U.S. patent application number 14/822462 was filed with the patent office on 2016-03-03 for vacuum machine, compressor, and piston.
The applicant listed for this patent is SHINANO KENSHI CO., LTD.. Invention is credited to Kazuhiro UEDA.
Application Number | 20160061196 14/822462 |
Document ID | / |
Family ID | 55404900 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160061196 |
Kind Code |
A1 |
UEDA; Kazuhiro |
March 3, 2016 |
VACUUM MACHINE, COMPRESSOR, AND PISTON
Abstract
A vacuum machine includes: a crankcase; a cylinder body fixed to
the crankcase; a cylinder head fixed to a distal end of the
cylinder body; and a piston reciprocating within the cylinder body,
wherein the piston includes: a piston rod; a piston head fixed to a
distal end of the piston rod and defining a chamber in cooperation
with the cylinder body and the cylinder head; and a check valve
arranged within a space formed between the piston rod and the
piston head, the piston rod and the piston head each includes a
through-hole communicating with the space, and the check valve is
elastically deformable within the space so as to open and close one
of the through holes of the piston rod and the piston head.
Inventors: |
UEDA; Kazuhiro; (Ueda-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHINANO KENSHI CO., LTD. |
Ueda-shi |
|
JP |
|
|
Family ID: |
55404900 |
Appl. No.: |
14/822462 |
Filed: |
August 10, 2015 |
Current U.S.
Class: |
417/443 |
Current CPC
Class: |
F04B 37/14 20130101;
F04B 39/10 20130101; F04B 39/0005 20130101 |
International
Class: |
F04B 37/14 20060101
F04B037/14; F04B 39/10 20060101 F04B039/10 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 26, 2014 |
JP |
2014-141862 |
Aug 26, 2014 |
JP |
2014-171875 |
Claims
1. A vacuum machine comprising: a crankcase; a cylinder body fixed
to the crankcase; a cylinder head fixed to a distal end of the
cylinder body; and a piston reciprocating within the cylinder body,
wherein the piston includes: a piston rod; a piston head fixed to a
distal end of the piston rod and defining a chamber in cooperation
with the cylinder body and the cylinder head; and a check valve
arranged within a space formed between the piston rod and the
piston head, the piston rod and the piston head each includes a
through-hole communicating with the space, and the check valve is
elastically deformable within the space so as to open and close one
of the through holes of the piston rod and the piston head.
2. The vacuum machine of claim 1, wherein the check valve abuts
with the one of the piston rod and the piston head to close the one
of the through holes of the piston rod and the piston head, and is
elastically deformed away from the one of the through holes of the
piston rod and the piston head and closer to the other one of the
through holes of the piston rod and the piston head to open the one
of the through holes of the piston rod and the piston head.
3. The vacuum machine of claim 1, wherein the check valve is fixed
to the one of the piston rod and the piston head by a fixation
member, and the other one of the through-holes of the piston rod
and the piston head releases the fixation member.
4. The vacuum machine of claim 1, wherein the cylinder head
includes a partition wall portion defining the chamber in
cooperation with the piston head, the partition wall portion is
formed with a communication hole communicating with the chamber, an
opening and closing member opening and closing the communication
hole being fixed to the partition wall portion by a cylinder side
fixation member, and the through-hole of the piston head releases
the cylinder side fixation member projecting in the chamber in
accordance with reciprocation of the piston head.
5. A compressor comprising: a crankcase; a cylinder body fixed to
the crankcase; a cylinder head fixed to a distal end of the
cylinder body; and a piston reciprocating within the cylinder body,
wherein the piston includes: a piston rod; a piston head fixed to a
distal end of the piston rod and defining a chamber in cooperation
with the cylinder body and the cylinder head; and a check valve
arranged within a space formed between the piston rod and the
piston head, the piston rod and the piston head each includes a
through-hole communicating with the space, and the check valve is
elastically deformable within the space so as to open and close one
of the through holes of the piston rod and the piston head.
6. The compressor of claim 5, wherein the check valve abuts with
the one of the piston rod and the piston head to close the one of
the through holes of the piston rod and the piston head, and is
elastically deformed away from the one of the through holes of the
piston rod and the piston head and closer to the other one of the
through holes of the piston rod and the piston head to open the one
of the through holes of the piston rod and the piston head.
7. The compressor of claim 5, wherein the check valve is fixed to
the one of the piston rod and the piston head by a fixation member,
and the other one of the through-holes of the piston rod and the
piston head releases the fixation member.
8. The compressor of claim 5, wherein the cylinder head includes a
partition wall portion defining the chamber in cooperation with the
piston head, the partition wall portion is formed with a
communication hole communicating with the chamber, an opening and
closing member opening and closing the communication hole being
fixed to the partition wall portion by a cylinder side fixation
member, and the through-hole of the piston head releases the
cylinder side fixation member projecting in the chamber in
accordance with reciprocation of the piston head.
9. A piston comprising: a piston rod; a piston head fixed to a
distal end of the piston rod; and a check valve arranged within a
space formed between the piston rod and the piston head, wherein
the piston rod and the piston head each includes a through-hole
communicating with the space, and the check valve is elastically
deformable within the space so as to open and close one of the
through holes of the piston rod and the piston head.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority of the prior Japanese Patent Application No. 2014-171862,
filed on Aug. 26, 2014, and the prior Japanese Patent Application
No. 2014-171875, filed on Aug. 26, 2014, the entire contents of
which are incorporated herein by reference.
BACKGROUND
[0002] (i) Technical Field
[0003] The present invention relates to a vacuum machine, a
compressor, and a piston.
[0004] (ii) Related Art
[0005] There are known a vacuum machine and a compressor in which a
piston reciprocates. In some cases, a distal end of the piston is
formed with a through-hole, and a check valve opening and closing
this through-hole is fixed to a piston. This check valve is
repeatedly and elastically deformed to open and close the
through-hole in conjunction with the reciprocation of the piston.
Japanese Patent Application Publication No. 2008-95700 discloses a
related device.
[0006] When such a check valve is greatly elastically deformed
repeatedly, the durability of the check valve might deteriorate.
Also, when the check valve is deformed greatly, it might be
plastically deformed to exceed its elastic limit, so that the
through-hole cannot be closed adequately.
SUMMARY
[0007] According to an aspect of the present invention, there is
provided a vacuum machine including: a crankcase; a cylinder body
fixed to the crankcase; a cylinder head fixed to a distal end of
the cylinder body; and a piston reciprocating within the cylinder
body, wherein the piston includes: a piston rod; a piston head
fixed to a distal end of the piston rod and defining a chamber in
cooperation with the cylinder body and the cylinder head; and a
check valve arranged within a space formed between the piston rod
and the piston head, the piston rod and the piston head each
includes a through-hole communicating with the space, and the check
valve is elastically deformable within the space so as to open and
close one of the through holes of the piston rod and the piston
head.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front view of a vacuum machine;
[0009] FIG. 2 is a side view of the vacuum machine;
[0010] FIG. 3 is a rear view of the vacuum machine;
[0011] FIG. 4 is a partial enlarged view of FIG. 3;
[0012] FIG. 5 is a partially sectional view of a vacuum machine
according to a comparative example;
[0013] FIG. 6 is front view of a compressor;
[0014] FIG. 7 is a rear view of the compressor;
[0015] FIG. 8 is a partially enlarged view of FIG. 7; and
[0016] FIG. 9 is a partially sectional view of a compressor
according to a comparative example.
DETAILED DESCRIPTION
[0017] FIGS. 1, 2, and 3 are front, side, and rear views of a
vacuum machine A, respectively. Additionally, FIGS. 1 and 3
illustrate a partial section. The vacuum machine A includes: four
cylinders 10a to 10d; a crankcase 20 to which the four cylinders
10a to 10d are fixed; and a motor M arranged on an upper portion of
the crankcase 20. The cylinders 10a to 10d are fixed around the
crankcase 20. The cylinder 10a includes: a cylinder body 12a fixed
to the crankcase 20; and a cylinder head 15a fixed to the cylinder
body 12a. A partition plate 14a intervenes between the cylinder
body 12a and the cylinder head 15a. Likewise, the cylinders 10b to
10d include cylinder bodies 12b to 12d and cylinder heads 15b to
15d, respectively. Between the cylinder bodies 12b to 12d and the
cylinder heads 15b to 15d, partition plates 14b to 14d intervene,
respectively. The partition plates 14a to 14d are examples of
partition wall portions. The cylinder 10a and the like and the
crankcase 20 are made of metal such as aluminum with good heat
radiation. A nozzle N is fixed to the crankcase 20. The nozzle N
exhausts air introduced into the crankcase 20 to the outside. Also,
apertures Hal and Hat are provided in the cylinder head 15a.
Likewise, apertures Hb1, Hb2, Hc1, Hc2, Hd1, and Hd2 are provided
in the cylinder heads 15b to 15d, respectively.
[0018] The motor M illustrated in FIG. 2 includes coils not
illustrated, a rotor 40, a stator not illustrated, and a printed
circuit board PB. The stator is fixed to the crankcase 20. Around
the stator, plural coils are wound. The coils are electrically
connected to the printed circuit board PB. The stator is excited by
energizing the coils. The rotor 40 includes a rotational shaft 42,
a yoke 44, and one or more permanent magnets not illustrated. The
rotational shaft 42 is rotatably supported by plural bearings
arranged within the crankcase 20. The yoke 44 is fixed to the
rotational shaft 42, and the yoke 44 rotates with the rotational
shaft 42. The yoke 44 has a substantially cylindrical shape, and is
made of metal. One or more plural permanent magnets are fixed to an
internal circumferential surface of the yoke 44. The permanent
magnet faces an outer circumferential surface of the stator. The
stator is excited by energizing the coils. Thus, the magnetic
attractive force and the magnetic repulsive force exert between the
permanent magnet and the stator. This magnetic force causes the
rotor 40 to rotate. Thus, the motor M is a motor of an outer rotor
type in which the rotor 40 rotates.
[0019] A fan F is fixed to the yoke 44 of the rotor 40, and rotates
with the rotor 40. Thus, the crankcase 20 and the cylinders 10a to
10d are cooled. Also, an increase in temperature depending on
friction of moveable portions can be suppressed.
[0020] Next, the internal structure of the cylinder 10a will be
described. As illustrated in FIG. 3, the cylinder body 12a is fixed
to an outer peripheral wall of the crankcase 20 to communicate with
a hole formed in the outer peripheral wall of the crankcase 20.
Also, the cylinder head 15a is fixed to a distal end of the
cylinder body 12a through the partition plate 14a. A chamber 13a is
formed in the cylinder body 12a. The chamber 13a is defined by the
cylinder body 12a, a distal end of the piston Pa, and the partition
plate 14a. The piston Pa reciprocates in conjunction with the
rotation of the motor M, so a capacity of the chamber 13a increases
and decreases. A proximal end of the piston Pa is located within
the crankcase 20, and is coupled with the rotational shaft 42
receiving rotary power through a bearing from the motor M.
Specifically, the proximal end of the piston Pa is coupled at the
eccentric position with respect to the central position of the
rotational shaft 42, and the piston Pa reciprocates in conjunction
with the one-way rotation of the rotational shaft 42. Pistons not
illustrated and moving within the other cylinders 10b to 10d are
provided therewithin, respectively. As for these pistons,
positional phases are shifted at intervals of 90 degrees. These
pistons reciprocate to introduce air into the cylinders 10a to 10d
and the crankcase 20 through the aperture Ha1, Hb1, Hc1, and Hd1,
which exhausts air from the nozzle N.
[0021] Next, the inner structure of the cylinder 10a will be
described in detail. FIG. 4 is a partially enlarged view of FIG. 3.
The cylinder head 15a includes: rooms 18a and 19a partitioned from
each other; and the apertures Hal and Ha2 respectively
communicating with the rooms 18a and 19a. The partition plate 14a
is formed with a hole portion 16a communicating the room 18a with
the chamber 13a. Note that the partition plate 14a is not formed
with a through-hole communicating the room 19a and the chamber 13a.
However, the through-hole communicating the room 19a with the
chamber 13a may be formed and sealed.
[0022] A check valve V1 is fixed to the partition plate 14a. The
check valve V1 allows air to flow into the chamber 13a through the
hole portion 16a from the room 18a, but restricts air from flowing
reversely. The check valve V1 is fixed to an inner surface of the
partition plate 14a facing the piston head 25a by a screw S1. A
proximal end of the check valve V1 is fixed to the partition plate
14a by the screw S1, a distal end of the check valve V1 is a free
end, and the check valve V1 is elastically deformed to open and
close the hole portion 16a. The check valve V1 is elastically
deformed by a difference in inner pressure between the chamber 13a
and the room 18a, so the hole portion 16a is opened and closed. The
check valve Vi is arranged within the chamber 13a. The check valve
V1 is made of metal such as a stainless steel, but is not limited
to this.
[0023] The piston Pa includes: a piston rod 21a having a proximal
end coupled with the rotational shaft 42; and a piston head 25a
fixed to a distal end of the piston rod 21a by a screw not
illustrated. A sealing ring C is sandwiched between the piston rod
21a and the piston head 25a. The sealing ring C seals between the
piston Pa and an inner side surface of the cylinder body 12a, and
is made of material such as fluoric resin with a good
self-lubrication property.
[0024] A space SP is formed between the distal end of the piston
rod 21a and the piston head 25a.
[0025] Specifically, a recess portion 23a is formed in the distal
end of the piston rod 21a, and a stepped portion 24a is formed
around the recess portion 23a. The piston head 25a is fitted into
and fixed to the stepped portion 24a. A through-hole 26a
communicating with the space SP is formed in the piston head 25a. A
through-hole 22a communicating with the space SP is formed in the
piston rod 21a.
[0026] A check valve V2 is fixed to an inner surface, of the piston
head 25a facing the recess portion 23a of the piston rod 21a, by a
screw S2. The screw S2 is an example of a fixation member. A
proximal end of the check valve V2 is fixed to the piston head 25a
by the screw S2, a distal end of the check valve V2 is a free end,
and the check valve V2 is elastically deformed to open and close
the through-hole 26a. The check valve V2 is elastically deformed by
a difference in inner pressure between the chamber 13a and the
crankcase 20, so the through-hole 26a is opened and closed. The
check valve V2 is provided within the space SP and is elastically
deformable therewithin. The check valve V2 permits air to flow into
the crankcase 20 through the through-hole 26a, the space SP, and
the through-hole 22a from the chamber 13a, but restricts air from
reversely flowing. The check valve V2 is made of metal such as
stainless steel, but is not limited to this. The check valve V2 is
a member that has a plate shape having a certain thickness so as to
be elastically deformable.
[0027] When the reciprocation of the piston Pa causes the capacity
of the chamber 13a to increase from the minimum to the maximum, air
is introduced into the room 18a through the aperture Ha1 from the
outside, and the distal end of the check valve V1 is elastically
deformed to be bent away from the hole portion 16a, which opens the
hole portion 16a. Thus, air is introduced into the chamber 13a.
When the capacity of the chamber 13a decreases from the maximum to
the minimum, the distal end of the check valve V2 is elastically
deformed to be bent away from the through-hole 26a and opens the
through-hole 26a, which introduces air from the chamber 13a to the
crankcase 20 through the through-hole 26a, the space SP, and the
through-hole 22a. Additionally, at this time, the check valve V1 is
kept closing the hole portion 16a by the inner pressure of the
chamber 13a. In this way, air is introduced into the crankcase 20
through the chamber 13a from the outside by the reciprocation of
the piston Pa. Note that the pistons respectively arranged within
the cylinders 10b to 10d have the similar structure. Thus, air is
introduced in the crankcase 20 from the outside by the
reciprocation of these pistons.
[0028] As illustrated in FIG. 4, the check valve V2 is arranged
between the distal end of the piston rod 21a and the piston head
25a. Thus, when the distal end of the check valve V2 is elastically
deformed to be bent away from the through-hole 26a, the distal end
of the check valve V2 abuts with a bottom surface of the recess
portion 23a, so that the check valve V2 is restricted from being
further elastically deformed. Thus, the maximum amount of the
elastic deformation of the check valve V2 is restricted to a
certain amount. For example, when the great elastic deformation is
repeated in such a check valve V2, the durability of the check
valve might deteriorates. Also, when the check valve is deformed
greatly, it might be plastically deformed to exceed its elastic
limit, so that the through-hole cannot be closed adequately. Thus,
the performance of the check valve might deteriorate. In the
present embodiment, the check valve V2 is arranged between the
piston rod 21a and the piston head 25a, and the elastic deformation
amount is restricted by the piston rod 21a. This can suppress the
deterioration in the performance of the check valve V2 caused by a
too large amount of the elastic deformation.
[0029] Also, the through-hole 22a releases the screw S2 fixing the
check valve V2 to the piston head 25a. Specifically, the
through-hole 22a is formed coaxially with the screw S2 so as not to
interfere with a head portion of the screw S2 protruding to the
space SP. Thus, regardless of the protruding amount of the screw
S2, the thickness of the space SP can be designed. Therefore, for
example, the thickness of the space SP can be designed smaller than
that of the head portion of the screw S2, and the total thickness
of the distal end of the piston rod 21a and the piston head 25a can
be designed small.
[0030] Also, the through-hole 26a is formed a such a position as to
release the head portion of the screw S1 protruding into the
chamber 13a. Therefore, the screw S1 avoids interfering with the
piston head 25a. Thus, even if the head portion of the screw S1
protrudes into the chamber 13a, the through-hole 26a releases the
head portion of the screw S1, so the minimum of the capacity of the
chamber 13a can be small as much as possible, thereby ensuring the
ratio of the maximum to the minimum of the capacity of the chamber
13a. This can further introduce air into the crankcase 20. The
screw S1 is an example of a cylinder side fixation member.
[0031] Next, a description will be given of a vacuum machine X
according to a comparative example having structure different from
the vacuum machine A. FIG. 5 is a partially sectional view of the
vacuum machine X according to the comparative example, and FIG. 5
corresponds to FIG. 4. Additionally, similar components are
designated with similar reference numerals and a duplicated
description of those components will be omitted. The cylinder 10x
includes a cylinder body 12x, a partition plate 14x, a cylinder
head 15x. A check valve V1x, arranged within a room 18x and fixed
to an outer surface of the partition plate 14x by a screw not
illustrated, permits air to pass to a chamber 13x through a hole
portion 16x from the room 18x, but restricts air from passing
reversely. The check valve V2x, arranged within the chamber 13x and
fixed to an inner surface of the partition plate 14x by a screw not
illustrated, permits air to pass to a room 19x through a hole
portion 17x from chamber 13x, but restricts air from passing
reversely. A piston Px includes a piston rod 21x, a piston head
25x, and a sealing ring Cx. A space is not provided between the
piston rod 21x and the piston head 25x.
[0032] Air is introduced into the chamber 13x through an aperture
Hx1, the room 18x, and the hole portion 16x by the reciprocation of
the piston Px, and air is exhausted outside from the chamber 13x
through the hole portion 17x, the room 19x, and an aperture Hx2. In
the vacuum machine X, air is not introduced into the crankcase 20x.
Thus, most of the flowing passage of air is the rooms 18x and 19x
of the cylinder head 15x located at the outer side of the vacuum
machine X. For this reason, there is a certain limit to a decrease
in leak of sound of air flowing. In the vacuum machine A according
to the present embodiment, air flows through the crankcase 20 as
illustrated in FIG. 4. This can suppress sound of air flowing
through the crankcase 20 from being leaked, and can suppress the
noise. Also, in the vacuum machine A according to the present
embodiment, air flows from the narrow space chamber 13a to the wide
space crankcase 20, so the noise is suppressed by the operation
similar to car mufflers.
[0033] Also, in a case where the vacuum machine X according to the
comparative example has plural pairs of the cylinder body, the
cylinder head, and the piston, it is considered that a passage for
meeting air exhausted from the cylinder heads is provided outside
the crankcase 20x. However, in the vacuum machine A according to
the present embodiment, air introduced from the cylinder heads 15a
to 15d are met within the crankcase 20. For this reason, a special
passage for meeting air is not needed. Thus, as for the vacuum
machine A according to the present embodiment, an increase in the
number of parts is suppressed, and an increase in size of the
device is also suppressed.
[0034] Also, in the vacuum machine X according to the comparative
example, air does not flow in the crankcase 20x. In the vacuum
machine A according to the present embodiment, air flows through
the crankcase 20 and is exhausted outside from the nozzle N. Thus,
the crankcase 20 can be cooled, and the heat degradation in parts
of the crankcase 20 can be suppressed.
[0035] Next, a compressor A' according to the present embodiment
will be described. FIGS. 6 and 7 are front and rear views of the
compressor A', respectively. FIG. 6 corresponds to FIG. 1, and FIG.
7 corresponds to FIG. 3. Additionally, similar components are
designated with similar reference numerals and a duplicated
description of those components will be omitted. Unlike the vacuum
machine A, in the compressor A', air is introduced into the
crankcase 20 through the nozzle N.
[0036] FIG. 8 is a partially enlarged view of FIG. 7. A partition
plate 14a' is formed with a hole portion 16a' communicating the
room 19a with the chamber 13a. The partition plate 14a' is not
formed with a through-hole communicating the room 18a with the
chamber 13a, but may be formed with a through-hole communicating
the room 18a with the chamber 13a, and this through-hole may be
sealed.
[0037] A check valve V1' is fixed to the partition plate 14a'. The
check valve V1' permits air to flow to the room 19a through the
hole portion 16a' from the chamber 13a, but restrict air from
flowing reversely. The check valve V1' is fixed to an outer
surface, of the partition plate 14a' facing the cylinder head 15a,
by a screw S1'. The screw S1' and the hole portion 16a' are
arranged in the central axis direction of the rotational shaft 42.
Thus, the check valve V1' is fixed to the partition plate 14a' in
such a posture that the central axis direction of the rotational
shaft 42 is the longer direction. A proximal end of the check valve
V1' is fixed to the partition plate 14a' by the screw S1', a distal
end of the check valve V1' is a free end, and the check valve V1'
is elastically deformed so as to open and close the hole portion
16a'. The check valve V1' is elastically deformed by a difference
in inner pressure between the chamber 13a and a room 19a, so the
hole portion 16a' is opened and closed. The check valve V1' is
provided within the room 19a.
[0038] A piston Pa' includes: a piston rod 21a'; a piston head 25a'
fixed to a distal end of the piston rod 21a' by a screw not
illustrated; and a seal ring C' sandwiched between the piston rod
21a' and the piston head 25a'. The check valve V2' is fixed to a
bottom surface, of the recess portion 23a of the piston rod 21a'
facing the piston head 25a', by a screw S2'. The screw S2' is an
example of a fixation member. A proximal end of the check valve V2'
is fixed to the piston rod 21a' by the screw S2', a distal end of
the check valve V2' is a free end, and the check valve V2' is
elastically deformed to open and close the through-hole 22a. The
check valve V2' is elastically deformed by a difference in inner
pressure between the chamber 13a and the crankcase 20, so that
through-hole 22a is opened and closed. The check valve V2' is
provided and is elastically deformable within the space SP. The
check valve V2' permits air to flow into the crankcase 20 through
the through-hole 26a, the space SP, and the through-hole 22a from
the chamber 13a, but restrict air from flowing reversely.
[0039] When the capacity of the chamber 13a is increased from the
minimum by the reciprocation of the piston Pa', the distal end of
the check valve V2' is elastically deformed to be bent away from
the through-hole 22a, which opens the through-hole 22a. Thus, air
introduced into the crankcase 20 through the nozzle N is introduced
into the chamber 13a through the through-hole 22a, the space SP,
and the through-hole 26a. When the capacity of the chamber 13a
decreases from the maximum, the distal end of the check valve V1'
is elastically deformed to be bent away from the hole portion 16a',
which opens the hole portion 16a'. Thus, air is introduced into the
room 19a from the chamber 13a, and is exhausted from the aperture
Ha2.
[0040] When the distal end of the check valve V2' is elastically
deformed to be bent away from the through-hole 22a, the distal end
of the check valve V2' abuts with an inner surface of the piston
head 25a', so that the check valve V2' is restricted from being
further elastically deformed. Thus, the maximum amount of the
elastic deformation of the check valve V2' is restricted to a
certain amount. This can suppress the deterioration in the
performance of the check valve V2' caused by a too large amount of
the elastic deformation.
[0041] Also, the through-hole 26a releases the screw S2' fixing the
check valve V2'. Specifically, the through-hole 26a is formed
coaxially with the screw S2' so as not to interfere with a head
portion of the screw S2' protruding to the space SP. Therefore, for
example, the thickness of the space SP can be designed smaller than
that of the head portion of the screw S2', and the total thickness
of the distal end of the piston rod 21a' and the piston head 25a'
can be designed small.
[0042] Also, the through-hole 26a is formed at such a position as
to release a lower end portion of the screw S1' protruding into the
chamber 13a in accordance with the reciprocation of the piston Pa'.
Therefore, the screw S1' avoids interfering with the piston head
25a. Thus, the minimum of the capacity of the chamber 13a can be
small as much as possible, thereby exhausting the large amount of
air from the crankcase 20. The screw S1' is an example of a
cylinder side fixation member.
[0043] Next, a description will be given of a compressor X'
according to a comparative example having structure different from
the compressor A'. FIG. 9 is a partially sectional view of the
compressor X' according to the comparative example. FIG. 9 is the
partially sectional view of a side view of the compressor X', and
illustrates the compressor X' when viewed along the cross section
parallel with a rotational shaft. An upper portion of the
compressor X' is located at the left side of FIG. 9, and the bottom
side is located at the right side of FIG. 9. Additionally, similar
components are designated with similar reference numerals and a
duplicated description of those components will be omitted. A
cylinder 10x' includes a cylinder body 12x', a partition plate
14x', and a cylinder head 15x'. A check valve V1x', arranged within
a room 19x' and fixed to an outer surface of the partition plate
14x' by a screw not illustrated, permits air to pass to a chamber
19x' through a hole portion 17x' from the room 13x', but restricts
air from passing reversely. A check valve V2x', arranged within the
chamber 13x' and fixed to an outer surface of the piston head 25x'
by a screw S2x', permits air to pass to a chamber 13x' from a
crankcase 20x', but restricts air from flowing reversely. The
piston Px' includes a piston rod 21x',a piston head 25x', and a
seal ring Cx'. The space is not provided between the piston rod
21x' and the piston head 25x'. Through-holes 22x' are 26x' directly
communicate with each other.
[0044] Air is introduced into the chamber 13x' through the
through-holes 22x' and 26x' from the crankcase 20x' by the
reciprocation of the piston Px', and air is exhausted outside from
an aperture Hx2' through the hole portion 17x' and the room 19x'.
As illustrated in FIG. 9, the check valve V2x' is fixed to the
outer surface of the piston head 25x'. Thus, when a capacity of the
chamber 13x' increases, a distal end of the check valve V2x' is
elastically deformed to be bent away from the through-hole 26x'. At
this time, the amount of the elastic deformation of the check valve
V2x' cannot be restricted. Thus, the amount of the elastic of
deformation of the check valve V2x' might be large, and the
performance might deteriorate.
[0045] Also, the check valve V2x' is elastically deformed such that
its distal end abuts with an inner surface of the partition plate
14x', so that contact noise might be made. In particular, when the
piston Px' reciprocates at high speed, the amount of the elastic
deformation of the check valve V2x' increases and the distal end of
the check valve V2x' abuts with the inner surface of the partition
plate 14x' in accordance with the reciprocation of the piston Px',
which might increases the noise. In the compressor A' according to
the present embodiment, the maximum amount of the elastic
deformation of the check valve V2' is restricted to be a certain
amount, which can also suppress an increase in the contact noise of
the piston head 25a' and the check valve V2'.
[0046] Also, the check valve V2x' is fixed to the outer surface of
the piston head 25x' facing the inner surface of the partition
plate 14x'. Therefore, in consideration of a position, a size, and
a shape of the check valve V2x', a shape of an inner surface of the
partition plate 14x' facing the check valve V2x' has to be
designed. In contrast, in the compressor A' according to the
present embodiment, the check valve V2' is arranged between the
piston head 25a' and the piston rod 21a', so the check valve V2'
does not abut with the partition plate 14a'. Thus, regardless of a
position, a size, and a shape of the check valve V2', the shape of
the inner surface of the partition plate 14a' can be designed.
Accordingly, the freedom degree of the design of the partition
plate 14a' improves.
[0047] While the exemplary embodiments of the present invention
have been illustrated in detail, the present invention is not
limited to the above-mentioned embodiments, and other embodiments,
variations and modifications may be made without departing from the
scope of the present invention.
[0048] The vacuum machine A and the compressor A' according to the
present embodiment each has four pairs of the cylinders 10a to 10d
and pistons, but are not limited to these. The vacuum machine and
the compressor each may have only one pair, two pairs, or three
pairs of the cylinders and pistons, and may have five or more pairs
of the cylinders and pistons.
[0049] The vacuum machine A according to the present embodiment
functions as a compressor, when an object product is connected to
the nozzle N that exhausts air. The compressor A' according to the
present embodiment functions as a vacuum machine, when an object
product is connected to the nozzle N that intakes air.
[0050] Note that, in the present embodiment, subject matters of
additional notes to be described later are supported. The subject
matters of the additional notes will be explained below.
[0051] There is known a vacuum machine in which a capacity of a
chamber increases depending on reciprocation of a piston within a
cylinder body fixed to a crankcase and in which air is sent from an
intake room to an exhaust room through this chamber. Japanese
Patent Application Publication No. 2008-95700 discloses a related
device.
[0052] The cylinder head is arranged in the outside of the
crankcase, and air flows to the exhaust room through the chamber
from the intake room in the cylinder head. In this way, a flowing
passage of air is mainly located at the outside of the crankcase,
so that there is a certain limit to a decrease in leak of sound of
air flowing.
[0053] According to an aspect of following additional notes, there
are provided a vacuum machine and a compressor in which noise is
restricted.
[0054] (additional note 1)
[0055] 1. A vacuum machine or a compressor comprising:
[0056] a crankcase;
[0057] a cylinder body fixed to the crankcase;
[0058] a cylinder head fixed to a distal end of the cylinder body;
and
[0059] a piston reciprocating within the cylinder body,
[0060] wherein
[0061] the piston includes: [0062] a piston rod; a piston head
fixed to a distal end of the piston rod and defining a chamber in
cooperation with the cylinder body and the cylinder head; and
[0063] a check valve arranged within a space formed between the
piston rod and the piston head,
[0064] the piston rod and the piston head each includes a
through-hole communicating with the space, and
[0065] the check valve is elastically deformed within the space so
as to open and close the through-hole of the piston rod or the
piston head, permits air to flow from one of the chamber and the
crankcase to the other one of the chamber and the crankcase through
the through-holes of the piston rod and the piston head and the
space, and restrict air from flowing to the other one of the
chamber and the crankcase from the one of the chamber and the
crankcase.
[0066] (additional note 2)
[0067] 2. The vacuum machine or the compressor of additional note 1
comprising a plural pairs of the cylinder body, the cylinder head,
and the piston.
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