U.S. patent application number 16/251302 was filed with the patent office on 2019-07-25 for driving tool.
This patent application is currently assigned to MAX CO., LTD.. The applicant listed for this patent is MAX CO., LTD.. Invention is credited to Mitsuhiro KIMURA, Eiichi WATANABE, Yu YAMAMOTO, Takashi YUKI.
Application Number | 20190224832 16/251302 |
Document ID | / |
Family ID | 65041617 |
Filed Date | 2019-07-25 |
United States Patent
Application |
20190224832 |
Kind Code |
A1 |
WATANABE; Eiichi ; et
al. |
July 25, 2019 |
DRIVING TOOL
Abstract
A driving tool includes a striking cylinder including a piston
configured to be actuated by a combustion pressure of a mixed gas
of compressed oxidant and fuel, a combustion chamber in which the
mixed gas of compressed oxidant and fuel is to be combusted; a
valve member configured to open and close communication between the
striking cylinder and the combustion chamber, and a striking
cylinder exhaust valve configured to open and close communication
between the striking cylinder and an outside.
Inventors: |
WATANABE; Eiichi; (Tokyo,
JP) ; KIMURA; Mitsuhiro; (Tokyo, JP) ; YUKI;
Takashi; (Tokyo, JP) ; YAMAMOTO; Yu; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MAX CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
MAX CO., LTD.
Tokyo
JP
|
Family ID: |
65041617 |
Appl. No.: |
16/251302 |
Filed: |
January 18, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B25D 9/10 20130101; F01L
9/02 20130101; B25C 1/08 20130101; F02B 63/02 20130101 |
International
Class: |
B25C 1/08 20060101
B25C001/08; B25D 9/10 20060101 B25D009/10; F02B 63/02 20060101
F02B063/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 19, 2018 |
JP |
2018-007520 |
Jan 19, 2018 |
JP |
2018-007521 |
Jan 19, 2018 |
JP |
2018-007633 |
Feb 9, 2018 |
JP |
2018-022480 |
Feb 9, 2018 |
JP |
2018-022481 |
Feb 9, 2018 |
JP |
2018-022482 |
Feb 19, 2018 |
JP |
2018-026624 |
Apr 25, 2018 |
JP |
2018-084498 |
Apr 25, 2018 |
JP |
2018-084499 |
Apr 25, 2018 |
JP |
2018-084500 |
Apr 25, 2018 |
JP |
2018-084501 |
Claims
1. A driving tool comprising: a striking cylinder including a
piston configured to be actuated by a combustion pressure of a
mixed gas of compressed oxidant and fuel; a combustion chamber in
which the mixed gas of compressed oxidant and fuel is to be
combusted; a valve member configured to open and close
communication between the striking cylinder and the combustion
chamber; and a striking cylinder exhaust valve configured to open
and close communication between the striking cylinder and an
outside.
2. The driving tool according to claim 1, further comprising: a
combustion chamber exhaust valve configured to open and close
communication between the combustion chamber and the outside.
3. The driving tool according to claim 2, wherein an operation of
opening and closing the striking cylinder exhaust valve and an
operation of opening and closing the combustion chamber exhaust
valve are performed in conjunction with each other.
4. The driving tool according to claim 3, wherein the striking
cylinder exhaust valve and the combustion chamber exhaust valve are
integrally formed.
5. The driving tool according to claim 1, further comprising: a
main body part including the striking cylinder and the combustion
chamber; and a handle part extending from the main body part,
wherein the striking cylinder exhaust valve is provided at one side
part of the striking cylinder with respect to an extension
direction of the handle part.
6. The driving tool according to claim 5, wherein the striking
cylinder exhaust valve is configured to be actuated by axial
movement of the striking cylinder.
7. The driving tool according to claim 2, further comprising: a
main body part including the striking cylinder and the combustion
chamber, and a handle part extending from the main body part,
wherein the striking cylinder exhaust valve is provided at one side
part of the striking cylinder with respect to an extension
direction of the handle part, and the combustion chamber exhaust
valve is provided at one side part of the combustion chamber with
respect to the extension direction of the handle part.
8. The driving tool according to claim 7, wherein the striking
cylinder exhaust valve and the combustion chamber exhaust valve are
configured to be actuated by axial movement of the striking
cylinder.
9. The driving tool according to claim 1, wherein the striking
cylinder exhaust valve includes a striking cylinder exhaust port
provided at a top dead point position of the piston and configured
to communicate the outside and an inside of the striking cylinder.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Japanese Patent
Application No. 2018-007520 filed on Jan. 19, 2018, Japanese Patent
Application No. 2018-007521 filed on Jan. 19, 2018, Japanese Patent
Application No. 2018-007633 filed on Jan. 19, 2018, Japanese Patent
Application No. 2018-022480 filed on Feb. 9, 2018, Japanese Patent
Application No. 2018-022481 filed on Feb. 9, 2018, Japanese Patent
Application No. 2018-022482 filed on Feb. 9, 2018, Japanese Patent
Application No. 2018-026624 filed on Feb. 19, 2018, Japanese Patent
Application No. 2018-084498 filed on Apr. 25, 2018, Japanese Patent
Application No. 2018-084499, filed on Apr. 25, 2018, Japanese
Patent Application No. 2018-084500 filed on Apr. 25, 2018, and
Japanese Patent Application No. 2018-084501 filed on Apr. 25, 2018,
the entire contents of which are incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a driving tool configured
to combust a mixed gas of compressed oxidant and fuel and to be
driven by a combustion pressure.
BACKGROUND
[0003] A driving tool referred to as a nailing machine configured
to strike a fastener such as a nail by actuating a piston with a
striking cylinder by using a compressed air (compressed oxidant) as
a power source and driving a driver joined to the piston has been
known.
[0004] Also, a driving tool configured to strike a fastener such as
a nail by combusting a mixed gas of air and fuel and actuating a
striking cylinder by a combustion pressure has been known. In the
gas combustion type driving tool, the mixed gas of which a pressure
has been increased in advance is combusted to further increase the
combustion pressure. However, since the mixed gas of which a
pressure has been increased is generated, when the compressed air
is supplied to a combustion chamber, the striking cylinder is
actuated by a pressure of the compressed air before the mixed gas
is combusted.
[0005] Therefore, a driving tool including a head valve mechanism
configured to openably and closably partition a combustion chamber
in which a mixed gas of compressed air and fuel is to be combusted
and a striking cylinder has been suggested (for example, refer to
Patent Document 1).
[0006] Also, in the driving tool configured to actuate the striking
cylinder by the combustion pressure, in order to exhaust a gas
remaining in the combustion chamber after a piston of the striking
cylinder is actuated, the combustion chamber is provided with an
exhaust port. Further, a check valve is provided at a part at which
the combustion chamber and the striking cylinder are partitioned
therebetween, and the gas in the striking cylinder is sent from the
check valve to the combustion chamber, so that the gas is exhausted
from the exhaust port of the combustion chamber (for example, refer
to Patent Document 2).
[0007] Patent Document 1: JP-A-S51-58768
[0008] Patent Document 2: Japanese Patent No. 4,935,978B
[0009] In the driving tool configured to actuate the striking
cylinder by the combustion pressure, the mixed gas of compressed
air and fuel is combusted in the combustion chamber to open
communication between the striking cylinder and the combustion
chamber by the head valve mechanism, and the high temperature and
high pressure gas flows from the combustion chamber into the
striking cylinder, so that when a pressure in the combustion
chamber is lowered, the head valve mechanism is closed. For this
reason, while the piston returns from a bottom dead point position
to a top dead point position, it is not possible to exhaust the gas
in the striking cylinder from the exhaust port provided to the
combustion chamber to an outside, so that it is difficult to
securely return the piston to the top dead point position.
[0010] Therefore, the check valve is provided at the part at which
the combustion chamber and the striking cylinder are partitioned
therebetween, and the gas in the striking cylinder is sent from the
check valve to the combustion chamber, so that it is possible to
exhaust the gas in the striking cylinder from the exhaust port
provided to the combustion chamber to the outside. However,
according to the configuration where the check valve is provided at
the part at which the combustion chamber and the striking cylinder
are partitioned therebetween, it is necessary to secure a pressure
difference between the combustion chamber and the striking cylinder
so as to open the check valve. For this reason, when the pressure
in the striking cylinder is lowered as the gas in the striking
cylinder is exhausted from the exhaust port of the combustion
chamber to the outside through the check valve, the check valve may
be closed before the pressure in the striking cylinder is lower to
an atmospheric pressure, depending on the pressure in the
combustion chamber. In this case, it is not possible to securely
return the piston to the top dead point position due to a residual
pressure in the striking cylinder. Also, the check valve is
provided, so that the structure becomes complicated, and the
combustion chamber is enlarged so as to secure a volume of the
combustion chamber.
SUMMARY
[0011] The present disclosure has been made in view of the above
situations, and an object thereof is to provide a driving tool
capable of exhausting a gas in a striking cylinder without via a
combustion chamber.
[0012] One aspect of the present disclosure provides a driving tool
comprising: a striking cylinder including a piston configured to be
actuated by a combustion pressure of a mixed gas of compressed
oxidant and fuel; a combustion chamber in which the mixed gas of
compressed oxidant and fuel is to be combusted; a valve member
configured to open and close communication between the striking
cylinder and the combustion chamber; and a striking cylinder
exhaust valve configured to open and close communication between
the striking cylinder and an outside.
[0013] In the above configuration, the mixed gas of compressed
oxidant and fuel is combusted in the combustion chamber,
communication between the striking cylinder and the combustion
chamber is opened by the valve member, and the high temperature and
high pressure gas flows from the combustion chamber into the
striking cylinder, so that the piston is moved from the top dead
point position to the bottom dead point position and a striking
operation is thus performed. When communication between the
striking cylinder and the combustion chamber is closed by the valve
member as the pressure in the combustion chamber is lowered, the
gas in the striking cylinder is exhausted from the striking
cylinder to the outside by the exhaust valve while the piston
returns from the bottom dead point position to the top dead point
position.
[0014] In the above configuration, even when communication between
the striking cylinder and the combustion chamber is closed by the
valve member, it is possible to exhaust the gas in the striking
cylinder to the outside by the exhaust valve while the piston
returns from the bottom dead point position to the top dead point
position, so that it is possible to securely return the piston to
the top dead point position. Also, it is not necessary to provide a
check valve at a part at which the combustion chamber and the
striking cylinder are partitioned therebetween, and it is possible
to exhaust the gas in the striking cylinder to the outside,
irrespective of the pressure in the combustion chamber, to securely
return the piston to the top dead point position, to simplify the
structure because it is not necessary to provide the check valve,
and to suppress the combustion chamber from being enlarged.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a configuration view of main parts depicting an
example of a nailing machine of an embodiment.
[0016] FIG. 2 is an overall configuration view depicting an example
of the nailing machine of the embodiment.
[0017] FIG. 3 is an overall configuration view depicting an example
of the nailing machine of the embodiment.
[0018] FIG. 4 is a configuration view of main parts depicting an
example of the nailing machine of the embodiment and an operation
example.
[0019] FIG. 5 is a configuration view of main parts depicting an
example of the nailing machine of the embodiment and an operation
example.
[0020] FIG. 6 is a configuration view of main parts depicting an
example of the nailing machine of the embodiment and an operation
example.
[0021] FIG. 7 is a configuration view of main parts depicting an
example of the nailing machine of the embodiment and an operation
example.
DETAILED DESCRIPTION
[0022] Hereinafter, an embodiment of a nailing machine, which is an
example of the driving tool of the present disclosure, will be
described with reference to the drawings.
[0023] <Configuration Example of Nailing Machine of
Embodiment>
[0024] FIG. 1 is a configuration view of main parts depicting an
example of a nailing machine of an embodiment, and FIGS. 2 and 3
are overall configuration views depicting an example of the nailing
machine of the embodiment. Also, FIGS. 4 to 7 are configuration
views of main parts depicting an example of the nailing machine of
the embodiment and an operation example.
[0025] A nailing machine 1A of the embodiment includes a main body
part 10 and a handle part 11 extending from the main body part 10
and configured to be gripped by a hand. The nailing machine 1A
includes a nose part 12 provided at one side of the main body part
10 and configured to strike out a fastener therefrom. In below
descriptions, considering a using aspect of the nailing machine 1A,
the side at which the nose part 12 is provided is referred to as
`lower side`, and a side opposite to the side at which the nose
part 12 is provided is referred to as `upper side`. Also, a side at
which the handle part 11 is provided is referred to as `rear side`
and a side opposite to the side at which the handle part 11 is
provided is referred to as `front side`.
[0026] The nailing machine 1A includes a tank mounting part 13, to
which a fuel tank (not shown) having fuel filled therein is
detachably mounted and which is provided substantially in parallel
with the handle part 11 below the handle part. Also, the nailing
machine 1A includes a magazine 14 configured to share fasteners
with the nose part 12 and provided below the tank mounting part 13.
Also, the nailing machine 1A includes an air plug 15 to which an
air hose, to which compressed air (compressed oxidant) is to be
supplied from a supply source such as an air compressor, is
connected and which is provided to the tank mounting part 13, in
the embodiment.
[0027] Also, the nailing machine 1A includes an operation trigger
16 configured to actuate the nailing machine 1A and provided to the
handle part 11, and a battery mounting part 18 to which a battery
17 becoming a power supply of the nailing machine 1A is to be
mounted and which is provided to the handle part 11.
[0028] The nailing machine 1A includes a striking cylinder 2
configured to be actuated by a combustion pressure of a mixed gas
of compressed air and fuel, a combustion chamber 3 in which the
mixed gas of compressed air and fuel is to be combusted, a head
valve 4 configured to open and close communication between the
striking cylinder 2 and the combustion chamber 3, and a valve
support member 5 configured to support the head valve 4.
[0029] The striking cylinder 2 is an example of the striking
mechanism, and includes a driver 20 configured to strike out a
fastener supplied from the magazine 14 to the nose part 12 and a
piston 21 to which the driver 20 is provided. The striking cylinder
2 has a cylindrical space in which the piston 21 can be slid, and
is configured so that the driver 20 is to move along the extension
direction of the nose part 12 by a reciprocal operation of the
piston 21.
[0030] The striking cylinder 2 has a piston position restraint part
2a provided at a peripheral edge of an upper end and formed to have
a tapered shape of which a diameter increases upward. When the
piston 21 is moved upward, a piston ring 21a provided on an outer
peripheral surface of the piston 21 is engaged to the piston
position restraint part 2a, so that a top dead point position of
the piston 21 is defined. In the meantime, the engagement of the
piston 21 with the piston position restraint part 2a is released by
a force of pushing the piston 21 by a combustion pressure, so that
the piston 21 can move by the combustion pressure.
[0031] Also, the striking cylinder 2 includes a buffer material 22
with which the piston 21 is to collide. The buffer material 22 is
configured by an elastic member and is provided at a lower part of
the striking cylinder 2. In the striking cylinder 2, the piston 21
having moved downward by an operation of striking out a fastener
collides with the buffer material 22, so that movement ranges of
the driver 20 and the piston 21 are restrained.
[0032] The combustion chamber 3 is provided above the striking
cylinder 2 along axial directions of the driver 20 and the piston
21, which are an axial direction of the striking cylinder 2. The
striking cylinder 2 and the combustion chamber 3 are partitioned by
a partitioning part 50, and the partitioning part 50 is provided
with a striking cylinder inlet 51 through which high temperature
and high pressure combusted air is to pass. The striking cylinder
inlet 51 is an example of the striking mechanism inlet, and is
configured by forming a circular opening on axes of the driver 20
and the piston 21, which are the axial direction of the striking
cylinder 2.
[0033] The combustion chamber 3 has the valve support member 5
provided around the striking cylinder inlet 51, and a ring-shaped
space formed around the valve support member 5.
[0034] The head valve 4 is an example of the valve member, and is
configured by a cylindrical metal member. As shown in FIGS. 6 and
7, the head valve 4 has a circular planar valve surface 40 of which
a lower end face in an axial direction of the cylinder is closed.
The head valve 4 has a configuration where a diameter of the valve
surface 40 is larger than the striking cylinder inlet 51, and the
striking cylinder inlet 51 is closed in a state where the valve
surface 40 is in contact with the partitioning part 50.
[0035] The head valve 4 has a first seal part 41 and a second seal
part 42. The first seal part 41 is an example of the seal part, is
provided on an outer periphery of the valve surface 40 in the axial
direction, which is a moving direction of the head valve 4, and is
attached with a first seal material 41a. The first seal material
41a is configured by a metal ring referred to as a piston ring. The
first seal part 41 has a circumferential groove in which the first
seal material 41a is fitted. When the first seal material 41a is
attached to the first seal part, the first seal material 41a
protrudes from a circumferential surface by a predetermined amount.
In the case of the first seal part 41 of the embodiment, the two
first seal materials 41a are attached along the axial direction of
the head valve 4.
[0036] The second seal part 42 is an example of the seal part, is
provided on the outer periphery of the head valve 4 with being
spaced from the first seal part 41 by a predetermined distance
along the axial direction of the head valve 4, and is attached with
a second seal material 42a. The second seal material 42a is a
so-called O-ring made of an elastic body such as rubber. The second
seal part 42 has a circumferential groove in which the second seal
material 42a is fitted. When the second seal material 42a is
attached to the second seal part, the second seal material 42a
protrudes from a circumferential surface by a predetermined
amount.
[0037] The head valve 4 has a configuration where the first seal
part 41 and the second seal part 42 protrude outward from the
circumferential surface of the head valve 4 and a diameter of the
second seal part 42 is larger than a diameter of the first seal
part 41. The second seal part 42 has an actuation surface 43 that
is a surface facing the first seal part 41 and is to be pushed by a
high temperature and high pressure gas. The actuation surface 43 is
a ring-shaped surface.
[0038] The head valve 4 is configured to be urged in a direction of
the partitioning part 50 by a spring 44. The spring 44 is an
example of the urging member, and is configured by a coil spring.
An axis of the spring 44 is provided on the axes of the driver 20
and the piston 21, which are on the axis of the striking cylinder
2, i.e., is provided coaxially with the head valve 4 and the
striking cylinder inlet 51. The spring 44 is introduced into a
concave part 45 having an open upper and formed in the head valve 4
along the axial direction, which is a moving direction of the head
valve 4, so that the head valve 4 and a part of the spring 44 are
arranged with overlapping each other. This arrangement is referred
to as `overlap arrangement`. Also, in order for the spring 44 to be
introduced into the concave part 45 of the head valve 4, a diameter
of the spring 44 is made to be smaller than the head valve 4 and
the striking cylinder 2.
[0039] A force of pushing the head valve 4 by the spring 44 is a
force of keeping a contact state of the valve surface 40 with the
partitioning part 50 in a state where the high temperature and high
pressure gas is not applied to the actuation surface 43.
[0040] The head valve 4 is supported to be moveable by the valve
support member 5.
[0041] The valve support member 5 is an example of the valve
support member and is configured by a cylindrical metal member. As
shown in FIGS. 6 and 7, in the embodiment, the valve support member
5 has the partitioning part 50 integrally provided at an axial
lower part of the cylinder. When the head valve 4 is put in the
cylindrical inner space, the first seal material 41a of the first
seal part 41 and the second seal material 42a of the second seal
part 42 of the head valve 4 are sliding contacted to the valve
support member 5. The valve support member 5 has different inner
diameters at parts to which the first seal material 41a of the
first seal part 41 and the second seal material 42a of the second
seal part 42 of the head valve 4 are sliding contacted, in
conformity to the respective seal parts.
[0042] When the head valve 4 is put in the valve support member 5,
an actuation space 52 is formed between the first seal part 41 and
second seal part 42 of the head valve 4 and an inner surface of the
valve support member 5. The actuation space 52 is an annular
space.
[0043] The valve support member 5 has a head valve inlet 53 for
connecting the combustion chamber 3 and the actuation space 52. The
head valve inlet 53 is configured by providing an opening
penetrating the valve support member 5 in the vicinity of the first
seal part 41 in a state where the valve surface 40 of the head
valve 4 is in contact with the partitioning part 50. The head valve
inlet 53 is formed on a side surface of the valve support member 5,
so that a flow path connecting the combustion chamber 3 and the
actuation space 52 becomes simple and an increase in inflow
resistance can be prevented.
[0044] As shown in FIG. 6, the head valve inlet 53 is coupled to
the actuation space 52 in the state where the valve surface 40 of
the head valve 4 is in contact with the partitioning part 50, i.e.,
in the state where the striking cylinder inlet 51 is closed by the
head valve 4.
[0045] In contrast, when the high temperature and high pressure gas
is applied to the actuation surface 43 of the head valve 4 and the
head valve 4 is thus moved upward, as shown in FIG. 7, the striking
cylinder inlet 51 is opened and the head valve inlet 53 is coupled
to the striking cylinder inlet 51.
[0046] The air to pass through the head valve inlet 53 is the high
temperature and high pressure air generated by combusting the mixed
gas of compressed air and fuel in the combustion chamber 3. Since
the high temperature and high pressure gas has lower viscosity than
the ordinary temperature and pressure air, the increase in
resistance against the gas flow is suppressed even though an
opening area of the head valve inlet 53 is small.
[0047] The first seal part 41 has the first seal material 41a
provided on the outer periphery thereof, and the first seal
material 41a is in contact with the inner surface of the valve
support member 5. Since the first seal material 41a is fitted in
the groove, a part to be exposed to the actuation space 52 is
suppressed to the minimum.
[0048] The second seal part 42 has the second seal material 42a
provided on the outer periphery thereof, and the second seal
material 42a is in contact with the inner surface of the valve
support member 5. Since the second seal material 42a is fitted in
the groove, a part to be exposed to the actuation space 52 is
suppressed to the minimum.
[0049] The valve support member 5 has a buffer material 54 with
which the head valve 4 is to collide. The buffer material 54 is
configured by an elastic member and is provided at an upper part of
the head valve 4. The head valve 4 having moved due to the high
temperature and high pressure gas applied to the actuation surface
43 of the head valve 4 collides with the buffer material 54 of the
valve support member 5, so that a movement range of the head valve
4 is restrained. In the meantime, although the movement range of
the head valve 4 is restrained by the buffer material 54, when the
head valve 4 collides with the buffer material 54, a shock is
absorbed by elastic deformation of the buffer material 54.
Therefore, a height of the head valve inlet 53 is preferably set to
be equal to or smaller than a stroke of the head valve 4. Thereby,
when the head valve 4 moves up to a position at which it is to
collide with the buffer material 54, the head valve 4 is not
exposed to the head valve inlet 53 and the head valve inlet 53 is
entirely opened. In this way, an opening amount of the head valve
inlet 53 is made constant, so that it is possible to stabilize an
output.
[0050] The upper opening of the combustion chamber 3 is sealed by a
head part 30. The head part 30 is provided with an ignition device
31. Also, the head part 30 is provided with a fuel supply port and
a compressed air supply port (not shown). Also, the buffer material
54 is provided to be in contact with the head part 30, so that the
shock to be applied to the head part 30 is buffered, durability of
a component is improved, a bolt for fastening the head part 30 to
the combustion chamber 3 is prevented from being unfastened, and an
electric noise is reduced.
[0051] The nailing machine 1A includes a blowback chamber 6 for
storing the gas to return the driver 20 and the piston 21 of the
striking cylinder 2. The blowback chamber 6 is provided around the
striking cylinder 2 and is coupled to an inside of the striking
cylinder 2 at an inlet/outlet 60 provided in the vicinity of the
buffer material 22.
[0052] The nailing machine 1A has an exhaust valve 7 configured to
exhaust the gas in the striking cylinder 2 and the combustion
chamber 3. The exhaust valve 7 is an example of the exhaust valve,
is provided at one side part of the striking cylinder 2 with
respect to the extension direction of the handle part 11, and
includes an exhaust piston 71 configured to be pushed by a gas
introduced into the blowback chamber 6, a first exhaust valve 72
configured to open and close a striking cylinder exhaust port 23
formed in the striking cylinder 2, a second exhaust valve 73
configured to open and close a combustion chamber exhaust port 32
formed in the combustion chamber 3, and a valve rod 74 coupling the
exhaust piston 71, the first exhaust valve 72 and the second
exhaust valve 73.
[0053] The exhaust piston 71, the first exhaust valve 72, the
second exhaust valve 73, and the valve rod 74 of the exhaust valve
7 are integrally made of metal. The exhaust valve 7 is configured
so that movement of the exhaust piston 71 is to be transmitted to
the first exhaust valve 72 and the second exhaust valve 73 via the
valve rod 74 and the first exhaust valve 72 and the second exhaust
valve 73 are thus to move in conjunction with the movement.
[0054] Also, the exhaust valve 7 includes an exhaust cylinder 75 to
be coupled to the blowback chamber 6, and an exhaust flow path
forming cylinder 76 to be coupled to the striking cylinder exhaust
port 23 and the combustion chamber exhaust port 32. The exhaust
cylinder 75 has a cylindrical space, in which the exhaust piston 71
can be slid, provided at one side part of the striking cylinder 2
with respect to the extension direction of the handle part 11, and
the exhaust valve 7 is configured to move in the extension
direction of the valve rod 74 by a reciprocal operation of the
exhaust piston 71.
[0055] The exhaust flow path forming cylinder 76 has a cylindrical
space, in which the first exhaust valve 72 and the second exhaust
valve 73 can be slid, provided at one side part of the striking
cylinder 2 with respect to the extension direction of the handle
part 11, and extends in a moving direction of the piston 21.
[0056] The striking cylinder exhaust port 23 is an example of the
exhaust port, is formed by an outer opening 23a penetrating the
exhaust flow path forming cylinder 76 and an outside and an inner
opening 23b penetrating the exhaust flow path forming cylinder 76
and the striking cylinder 2, and is configured to communicate the
outside and the inside of the striking cylinder 2 via the exhaust
flow path forming cylinder 76.
[0057] The inner opening 23b of the striking cylinder exhaust port
23 is provided to face a top dead point position of the piston 21
so that the gas in the striking cylinder 2 can be exhausted to the
outside by a return operation of the piston 21 from a bottom dead
point position to the top dead point position. Also, the outer
opening 23a of the striking cylinder exhaust port 23 opens toward a
side of the striking cylinder 2, and the outer opening 23a and the
inner opening 23b are arranged on one line.
[0058] The combustion chamber exhaust port 32 is an example of the
exhaust port, is formed by an outer opening 32a penetrating the
exhaust flow path forming cylinder 76 and the outside and an inner
opening 32b penetrating the exhaust flow path forming cylinder 76
and the combustion chamber 3, and is configured to communicate the
outside and the inside of the combustion chamber 3 via the exhaust
flow path forming cylinder 76. The exhaust flow path forming
cylinder 76 and the combustion chamber 3 are partitioned
therebetween by a wall part 76a, except a part at which the inner
opening 32b is provided.
[0059] The outer opening 32a of the combustion chamber exhaust port
32 opens toward a side of the striking cylinder 2, and the outer
opening 32a and the inner opening 32b are arranged with being
vertically offset in the moving direction of the second exhaust
valve 73.
[0060] The first exhaust valve 72 is an example of the striking
cylinder exhaust valve, has a substantially circular column shape
conforming to an inner peripheral surface of the exhaust flow path
forming cylinder 76, and has a pair of sealing parts 72a, 72b
having diameters capable of slidably contacting the inner surface
of the exhaust flow path forming cylinder 76 and a flow path
forming part 72c provided between the pair of sealing parts 72a,
72b, having a substantially circular column shape of a diameter
smaller than the sealing parts 72a, 72b and forming a space between
the flow path forming part and the inner surface of the exhaust
flow path forming cylinder 76.
[0061] The second exhaust valve 73 is an example of the combustion
chamber exhaust valve, has a substantially circular plate shape
conforming to the inner peripheral surface of the exhaust flow path
forming cylinder 76 and includes a sealing member 73a provided on
an outer peripheral surface thereof. The sealing member 73a is
configured by an O-ring, for example, and the sealing member 73a is
configured to sliding contact the inner peripheral surface of the
exhaust flow path forming cylinder 76.
[0062] As shown in FIG. 1, the first exhaust valve 72 has such a
configuration that when the flow path forming part 72c is moved to
a position facing the outer opening 23a and the inner opening 23b
of the striking cylinder exhaust port 23, the outer opening 23a and
the inner opening 23b of the striking cylinder exhaust port 23
communicate with each other by the space formed between the inner
surface of the exhaust flow path forming cylinder 76 and the flow
path forming part 72c and the striking cylinder exhaust port 23
opens.
[0063] Also, when the flow path forming part 72c is moved to the
position facing the outer opening 23a and the inner opening 23b of
the striking cylinder exhaust port 23, the upper exhaust flow path
forming cylinder 76 of the flow path forming part 72c is sealed by
one sealing part 72a and the lower exhaust flow path forming
cylinder 76 is sealed by the other sealing part 72b.
[0064] The sealing parts 72a, 72b are made of metal and are not
provided with a sealing member such as an O-ring but implement a
sealing structure by dimensions of outer diameters of the sealing
parts 72a, 72b and an inner diameter of the exhaust flow path
forming cylinder 76.
[0065] In a state where the striking cylinder exhaust port 23 is
opened by the first exhaust valve 72, the second exhaust valve 73
moves to the upper of the inner opening 32b of the combustion
chamber exhaust port 32, so that the inner opening 32b and the
outer opening 32a of the combustion chamber exhaust port 32
communicate with each other therebetween by the exhaust flow path
forming cylinder 76 and the combustion chamber exhaust port 32
opens, as shown in FIG. 1.
[0066] Also, in the state where the second exhaust valve 73 has
moved to the upper of the inner opening 32b of the combustion
chamber exhaust port 32, the sealing part 72a of the first exhaust
valve 72 is located below the outer opening 32a of the combustion
chamber exhaust port 32, so that the striking cylinder exhaust port
23 and the combustion chamber exhaust port 32 are sealed
therebetween by the sealing part 72a of the first exhaust valve
72.
[0067] In this way, the exhaust valve is configured by the first
exhaust valve 72, the striking cylinder exhaust port 23 and the
exhaust flow path forming cylinder 76, and the combustion chamber
exhaust valve is configured by the second exhaust valve 73, the
combustion chamber exhaust port 32 and the exhaust flow path
forming cylinder 76.
[0068] Also, the first exhaust valve 72, the striking cylinder
exhaust port 23 and the exhaust flow path forming cylinder 76 are
provided at one side part of the striking cylinder 2, and the
striking cylinder exhaust port 23 faces toward a side of the
striking cylinder 2. Also, the second exhaust valve 73, the
combustion chamber exhaust port 32 and the exhaust flow path
forming cylinder 76 are provided at one side part of the combustion
chamber 3, and the combustion chamber exhaust port 32 faces toward
a side of the combustion chamber 3.
[0069] Also, the exhaust valve 7 has a buffer material 77 with
which the exhaust piston 71 is to collide. The buffer material 77
is configured by an elastic member. The exhaust piston 71 collides
with the buffer material 77, so that a movement range of the
exhaust valve 7 is restrained.
[0070] Also, the exhaust valve 7 includes a spring 79 configured to
urge the valve rod 74 in a direction in which the first exhaust
valve 72 is to close the striking cylinder exhaust port 23 and the
second exhaust valve 73 is to close the combustion chamber exhaust
port 32. The spring 79 is an example of the urging member, is
configured by a compression coil spring, in the embodiment, and is
interposed between a spring receiving part 24 provided on a side
surface of the striking cylinder 2 and a spring retainer 74a
attached to the valve rod 74.
[0071] The spring retainer 74a is configured to move integrally
with the valve rod 74. When the valve rod 74 is moved in a
direction of compressing the spring 79 by the spring retainer 74a,
the first exhaust valve 72 opens the striking cylinder exhaust port
23 and the second exhaust valve 73 opens the combustion chamber
exhaust port 32. Also, when the valve rod 74 is moved in a
direction in which the spring 79 is to extend, the first exhaust
valve 72 closes the striking cylinder exhaust port 23 and the
second exhaust valve 73 closes the combustion chamber exhaust port
32.
[0072] The nailing machine 1A has a contact member 8 provided in
the nose part 12. The contact member 8 is provided to be moveable
along the extension direction of the nose part 12, and is urged by
a spring 80 in a direction in which it is to protrude from the nose
part 12. The contact member 8 is coupled to the exhaust valve 7 via
a link 81. The link 81 is attached to a side surface of the
striking cylinder 2 to be rotatable about a shaft 81d, which is a
support point, and is coupled at one end to the contact member 8.
The link 81 is urged by the spring 80 such as a tensile coil
spring, so that the contact member 8 rotates in the direction in
which it protrudes from the nose part 12.
[0073] Also, the other end of the link 81 is coupled to the exhaust
valve 7 via a long hole portion 78 formed in the valve rod 74. The
long hole portion 78 is an opening extending in the moving
direction of the valve rod 74 and is configured so that the valve
rod 74 can move in a state where a position of the link 81 is fixed
by the contact member 8.
[0074] Thereby, the link 81 rotates in conjunction with movement of
the contact member 8, so that the exhaust valve 7 is actuated.
Also, in the state where a position of the link 81 is fixed by the
contact member 8, the link 81 and the valve rod 74 are decoupled
with shapes of the link 81 and of the long hole portion 78 and the
exhaust valve 7 is actuated by the gas introduced into the blowback
chamber 6.
[0075] <Operation Example of Nailing Machine of
Embodiment>
[0076] Subsequently, an operation of the nailing machine 1A of the
embodiment is described with reference to the respective drawings.
In an initial state, the operation trigger 16 is not pulled, and
the contact member 8 is not pressed to a material to be struck and
is located at an initial position at which it is urged by the
spring 80 and protrudes from the nose part 12.
[0077] In a state where the contact member 8 is located at the
initial position, the link 81 is urged by the spring 80 to push the
long hole portion 78 of the valve rod 74, so that the valve rod 74
is moved in the direction of compressing the spring 79. As shown in
FIG. 1, the flow path forming part 72c of the first exhaust valve
72 of the exhaust valve 7 is moved to the position facing the outer
opening 23a and the inner opening 23b of the striking cylinder
exhaust port 23, so that the striking cylinder exhaust port 23 is
opened. Also, the second exhaust valve 73 is moved to the upper
side of the inner opening 32b of the combustion chamber exhaust
port 32 in conjunction with the first exhaust valve 72, so that the
inner opening 32b and the outer opening 32a of the combustion
chamber exhaust port 32 communicate with each other therebetween by
the exhaust flow path forming cylinder 76 and the combustion
chamber exhaust port 32 is opened. Thereby, the striking cylinder 2
and the combustion chamber 3 are opened to the atmosphere.
[0078] Also, the head valve 4 is pressed by the spring 44 and is
thus in the state where the valve surface 40 is in contact with the
partitioning part 50, i.e., in the state where the striking
cylinder inlet 51 is closed by the head valve 4. In this state, the
head valve inlet 53 is coupled to the actuation space 52.
[0079] When the contact member 8 is pressed to a material to be
struck, the link 81 is rotated in a direction of extending the
spring 80, so that the valve rod 74 is moved in the extension
direction of the spring 79 in conformity to the rotation of the
link 81 and the movement of the contact member 8 is transmitted to
the exhaust valve 7 by the link 81.
[0080] As shown in FIG. 4, the sealing part 72a of the first
exhaust valve 72 of the exhaust valve 7 is moved to the position
facing the outer opening 23a and the inner opening 23b of the
striking cylinder exhaust port 23, so that the striking cylinder
exhaust port 23 is closed. Also, the second exhaust valve 73 is
moved between the outer opening 32a and the inner opening 32b of
the combustion chamber exhaust port 32 in conjunction with the
first exhaust valve 72, so that the combustion chamber exhaust port
32 is closed. Thereby, the striking cylinder 2 and the combustion
chamber 3 are sealed.
[0081] Also, an air valve and a fuel valve (not shown) are opened
in conjunction with the contact member 8 and an operation of the
operation trigger 16, so that the gasified fuel and the compressed
air are supplied to the combustion chamber 3. For example, when the
contact member 8 is pressed to the material to be struck, the fuel
valve (not shown) is opened, and when the operation trigger 16 is
operated, the air valve (not shown) is opened. In the meantime,
when the contact member 8 is pressed to the material to be struck
and the operation trigger 16 is operated, the air valve and fuel
valve (not shown) may be opened at predetermined timings. Also,
when the contact member 8 is pressed to the material to be struck,
the air valve and fuel valve (not shown) may be opened at
predetermined timings.
[0082] When the compressed air is supplied to the combustion
chamber 3, a pressure in the combustion chamber 3 rises. During the
pressure rise in the combustion chamber 3 by the compressed air,
the head valve 4 is pressed by the spring 44, so that the valve
surface 40 is kept in the contact state with the partitioning part
50 and the striking cylinder inlet 51 is closed by the head valve
4. Therefore, even when the pressure in the combustion chamber 3
rises by the supply of the compressed air, the pressure does not
rise in the striking cylinder 2 and the piston 21 is not
actuated.
[0083] When the contact member 8 is pressed to the material to be
struck, the operation trigger 16 is operated to open the air valve
and the fuel valve (not shown) and the ignition device 31 is then
actuated at a predetermined timing, the mixed gas of compressed air
and fuel in the combustion chamber 3 is combusted. When the mixed
gas is combusted in the combustion chamber 3, the pressure in the
combustion chamber 3 rises and the high temperature and high
pressure gas is introduced from the head valve inlet 53 of the head
support member 5 into the actuation space 52.
[0084] When the pressure in the actuation space 52 rises, the high
temperature and high pressure gas is applied to the actuation
surface 43 of the head valve 4, so that the head valve 4 is moved
upward with compressing the spring 44. Here, when the pressure in
the actuation space 52 rises, the pressure is applied to the
surface of the first seal part 41 facing the actuation space 52,
too. However, since an area of the actuation surface 43 is larger,
the head valve 4 is moved upward with compressing the spring
44.
[0085] As shown in FIG. 7, when the head valve 4 is moved upward,
the striking cylinder inlet 51 is opened and the head valve inlet
53 is coupled to the striking cylinder inlet 51. Thereby, the high
temperature and high pressure gas is introduced from the combustion
chamber 3 into the striking cylinder 2 via the striking cylinder
inlet 51, so that the pressure of the striking cylinder 2
rises.
[0086] When the pressure of the striking cylinder 2 rises, the
piston 21 is pushed to move the piston 21 and the driver 20 in a
direction of striking out a fastener, so that a fastener striking
operation is performed. When the piston 21 and the driver 20 are
moved in the direction of striking out a fastener, the gas (air) in
a piston lower chamber 25a, which is one of chambers in the
striking cylinder 2 partitioned by the piston 21, flows from the
inlet/outlet 60 into the blowback chamber 6. Also, since the piston
21 passes through the inlet/outlet 60 with compressively deforming
the buffer material 22, a part of the high temperature and high
pressure gas having driven the piston 21 is introduced into the
blowback chamber 6.
[0087] When the gas (air) in the striking cylinder 2 flows into the
blowback chamber 6 and the pressure in the blowback chamber 6
rises, the exhaust piston 71 of the exhaust valve 7 is pushed, as
shown in FIG. 5. In the state where the exhaust valve 7 and the
link 81 are coupled via the long hole portion 78 formed in the
valve rod 74 and the position of the link 81 is fixed by the
contact member 8, the link 81 and the valve rod 74 are decoupled,
so that the exhaust valve 7 can move to the position at which it is
to collide with the buffer material 77. Since a moving amount of
the exhaust valve 7 is restrained by the buffer material 77, the
durability of the exhaust valve 7 is improved.
[0088] Thereby, when the exhaust piston 71 of the exhaust valve 7
is pushed, the first exhaust valve 72 is moved to the position at
which the flow path forming part 72c faces the outer opening 23a
and the inner opening 23b of the striking cylinder exhaust port 23,
so that the striking cylinder exhaust port 23 is opened. Also, the
second exhaust valve 73 is moved to the upper side of the inner
opening 32b of the combustion chamber exhaust port 32 in
conjunction with the first exhaust valve 72, so that the inner
opening 32b and the outer opening 32a of the combustion chamber
exhaust port 32 communicate with each other therebetween by the
exhaust flow path forming cylinder 76 and the combustion chamber
exhaust port 32 is opened.
[0089] Therefore, the striking cylinder 2 and the combustion
chamber 3 are opened to the atmosphere, and the gas in the
combustion chamber 3 is exhausted from the combustion chamber
exhaust port 32 to the outside. Also, the high temperature and high
pressure gas flows from the combustion chamber 3 into the striking
cylinder 2 through the striking cylinder inlet 51 and the pressure
in the combustion chamber 3 is thus lowered, so that the head valve
4 is pressed with the spring 44 and is moved to the position at
which the valve surface 40 is in contact with the partitioning part
50, and the striking cylinder inlet 51 is closed by the head valve
4.
[0090] When the piston 21 and the driver 20 are further moved in a
direction of striking out a fastener and the piston 21 is moved to
the bottom dead point and collides with the buffer material 22, the
piston 21 and the driver 20 intend to move upward by the elasticity
of the buffer material 22. When the piston 21 is moved to the upper
side of the inlet/outlet 60 through the inlet/outlet 60, the gas
(air) in the blowback chamber 6 of which the pressure has risen is
introduced into the striking cylinder 2 and pushes the piston 21.
When the piston 21 is pushed, the gas in a piston upper chamber
25b, which is the other chamber in the striking cylinder 2
partitioned by the piston 21, is exhausted from the striking
cylinder exhaust port 23 to the outside, and the piston 21 and the
driver 20 are returned to the top dead point.
[0091] When the contact member 8 separates from the material to be
struck, the link 81 is urged by the spring 80 to push the long hole
portion 78 of the valve rod 74, so that the valve rod 74 is moved
in the direction of compressing the spring 79. Thereby, as shown in
FIG. 1, the state where the first exhaust valve 72 opens the
striking cylinder exhaust port 23 and the second exhaust valve 73
opens the combustion chamber exhaust port 32 is kept.
[0092] <Operational Effect Example of Nailing Machine of
Embodiment>
[0093] In the nailing machine 1A of the embodiment, the compressed
air and the fuel are supplied to the combustion chamber 3, the
mixed gas is combusted to generate the high pressure gas and the
piston 21 of the striking cylinder 2 is pushed by the high pressure
gas, so that the force of pushing a fastener by the piston 21 and
the driver 20 increases.
[0094] Thereby, it is possible to increase an output for striking a
fastener, as compared to the related-art gas combustion type
nailing machine in which the ordinary pressure gas is used.
[0095] Also, the head valve 4 configured to open and close the
striking cylinder inlet 51 between the combustion chamber 3 and the
striking cylinder 2 is provided, so that it is possible to disable
the striking cylinder 2 from actuating even though the compressed
air is just supplied to the combustion chamber 3. Also, the head
valve 4 is actuated by the combustion pressure of the mixed gas, so
that it is not necessary to provide a separate drive source for
driving the head valve 4. Thereby, it is possible to simplify
structures of the head valve 4 and the drive mechanism thereof, to
miniaturize the device and to save the cost.
[0096] In the configuration where the head valve 4 is actuated by
the combustion pressure of the mixed gas, when the high temperature
and high pressure gas flows from the combustion chamber 3 into the
striking cylinder 2 through the striking cylinder inlet 51 and the
pressure in the combustion chamber 3 is thus lowered, the striking
cylinder inlet 51 is closed by the head valve 4. For this reason,
while the piston 21 returns from the bottom dead point position to
the top dead point position, it is not possible to exhaust the gas
in the striking cylinder 2 from the combustion chamber 3 to the
outside.
[0097] Therefore, the striking cylinder exhaust port 23 configured
to communicate the striking cylinder 2 and the outside and the
first exhaust valve 72 configured to open and close the striking
cylinder exhaust port 23 are provided. The striking cylinder
exhaust port 23 is provided to face the top dead point position of
the piston 21.
[0098] Thereby, even when the striking cylinder inlet 51 is closed
by the head valve 4 and communication between the striking cylinder
2 and the combustion chamber 3 is thus closed, while the piston 21
returns from the bottom dead point position to the top dead point
position, it is possible to exhaust the gas in the striking
cylinder 2 from the combustion chamber 3 to the outside. Therefore,
it is possible to securely return the piston 21 to the top dead
point position.
[0099] Also, the combustion chamber exhaust port 32 configured to
communicate the combustion chamber 3 and the outside and the second
exhaust valve 73 configured to open and close the combustion
chamber exhaust port 32 are provided, so that it is possible to
exhaust, to the outside, the gas remaining in the combustion
chamber 3 after actuating the piston 21 of the striking cylinder
2.
[0100] Also, the exhaust valve 7 is configured so that the first
exhaust valve 72 configured to open and close the striking cylinder
exhaust port 23 and the second exhaust valve 73 configured to open
and close the combustion chamber exhaust port 32 provided to the
combustion chamber 3 are to operate in conjunction with each other.
Thereby, it is possible to open the striking cylinder exhaust port
23 and the combustion chamber exhaust port 32 at predetermined
timings. In the embodiment, the first exhaust valve 72 and the
second exhaust valve 73 are integrally coupled by the valve rod 74,
so that it is possible to open the striking cylinder exhaust port
23 and the combustion chamber exhaust port 32 without delay of
actuation timing between the first exhaust valve 72 and the second
exhaust valve 73.
[0101] Also, the exhaust valve 7 is provided at one side part of
the striking cylinder 2 with respect to the extension direction of
the handle part 11. Thereby, as compared to a configuration where
the exhaust valve 7 is provided between the striking cylinder 2 and
the handle part 11, which is the rear side of the striking cylinder
2, it is possible to shorten a distance between the striking
cylinder 2 and the handle part 11. Therefore, a distance L1 between
a driver center P1 of the striking cylinder 2 and an operation
position P2 of the operation trigger 16 is shortened to improve the
operability. Also, as compared to a configuration where the exhaust
valve 7 is provided at a front side of the striking cylinder 2, it
is possible to shorten a distance L2 between a front surface P3 of
the main body part 10 and the driver center P1 of the striking
cylinder 2, so that it is possible to perform a striking operation
at a narrow place such as the vicinity of a wall surface, and to
improve the corner striking performance.
[0102] In the embodiment, the exhaust valve 7 configured to open
and close the striking cylinder exhaust port 23 and the combustion
chamber exhaust port 32 is actuated by the gas supplied to the
blowback chamber 6. However, the drive source of the exhaust valve
7 is not limited to the gas actuation. Also, in the embodiment, the
air is used as the oxidant, and the mixed gas of the compressed air
as the compressed oxidant and the fuel is used for actuation.
However, the oxidant is not limited to the compressed air and the
other oxidants may be used inasmuch as the oxidant contains oxygen
necessary for combustion of the fuel. For example, oxygen, ozone,
nitrogen monoxide and the like may also be used, instead of the
air.
[0103] 1A . . . nailing machine, 10 . . . main body part, 11 . . .
handle part, 12 . . . nose part, 13 . . . tank mounting part, 14 .
. . magazine, 15 . . . air plug, 16 . . . operation trigger, 17 . .
. battery, 18 . . . battery mounting part, 2 . . . striking
cylinder (striking mechanism), 2a . . . piston position restraint
part, 20 . . . driver, 21 . . . piston, 21a . . . piston ring, 22 .
. . buffer material, 23 . . . striking cylinder exhaust port(the
exhaust port), 23a . . . outer opening, 23b . . . inner opening, 24
. . . spring receiving part, 25a . . . piston lower chamber (one
chamber), 25b . . . piston upper chamber, 3 . . . combustion
chamber, 30 . . . head part, 31 . . . ignition device, 32 . . .
combustion chamber exhaust port (exhaust port), 32a . . . outer
opening, 32b . . . inner opening, 4 . . . head valve (valve
member), 40 . . . valve surface, 41 . . . first seal part, 41a . .
. first seal material, 42 . . . second seal part, 42a . . . second
seal material, 43 . . . actuation surface, 44 . . . spring, 45 . .
. concave part, 5 . . . valve support member, 50 . . . partitioning
part, 51 . . . striking cylinder inlet, 52 . . . actuation space,
53 . . . head valve inlet, 54 . . . buffer material, 6 . . .
blowback chamber, 60 . . . inlet/outlet, 7 . . . exhaust valve, 71
. . . exhaust piston, 72 . . . first exhaust valve (striking
cylinder exhaust valve), 72a . . . sealing part, 72b . . . sealing
part, 72c . . . flow path forming part, 73 . . . second exhaust
valve (combustion chamber exhaust valve), 73a . . . sealing member,
74 . . . valve rod, 74a . . . spring retainer, 75 . . . exhaust
cylinder, 76 . . . exhaust flow path forming cylinder, 76a . . .
wall part, 77 . . . buffer material, 78 . . . long hole portion, 79
. . . spring, 8 . . . contact member, 80 . . . spring, 81 . . .
link
* * * * *