U.S. patent application number 14/585979 was filed with the patent office on 2015-07-30 for vane type vacuum pump.
The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Masaya OTSUKA.
Application Number | 20150211520 14/585979 |
Document ID | / |
Family ID | 53523088 |
Filed Date | 2015-07-30 |
United States Patent
Application |
20150211520 |
Kind Code |
A1 |
OTSUKA; Masaya |
July 30, 2015 |
VANE TYPE VACUUM PUMP
Abstract
A vane type vacuum pump has a discharge port for discharging
suctioned air, and a reed valve part that opens and closes the
discharge port. The reed valve part includes a first reed valve
that is installed to cover the opening of the discharge port, and a
second reed valve that is superposed with the first reed valve. The
first reed valve and the second reed valve have different resonance
frequencies by having different thicknesses.
Inventors: |
OTSUKA; Masaya;
(Miyoshi-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Family ID: |
53523088 |
Appl. No.: |
14/585979 |
Filed: |
December 30, 2014 |
Current U.S.
Class: |
418/259 |
Current CPC
Class: |
F04C 18/08 20130101;
F04C 18/344 20130101; F04C 29/06 20130101; F04C 29/128
20130101 |
International
Class: |
F04C 29/12 20060101
F04C029/12; F04C 18/08 20060101 F04C018/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2014 |
JP |
2014-013400 |
Claims
1. A vane type vacuum pump that inhales a gas and discharges the
gas from a discharge port, the vane type vacuum pump comprising: a
first reed valve that is installed at the discharge port; and a
second reed valve that is superposed with the first reed valve and
has a resonance frequency which is different from that of the first
reed valve.
2. The vane type vacuum pump according to claim 1, wherein the
first reed valve and the second reed valve have different
thicknesses.
3. The vane type vacuum pump according to claim 1, wherein the
first reed valve and the second reed valve have different
shapes.
4. The vane type vacuum pump according to claim 1, wherein the
first reed valve and the second reed valve are formed with
different materials.
5. The vane type vacuum pump according to claim 1, further
comprising: a stopper member that is provided at an outer side of
the first reed valve and the second reed valve to limit a valve
open amount of the first reed valve and the second reed valve.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a vane type vacuum pump
that inhales a gas and discharges the gas from a discharge
port.
[0002] A conventional vane type vacuum pump is described in
Japanese Laid-Open Patent Publication No. 2012-057622. The vane
type vacuum pump described in Japanese Laid-Open Patent Publication
No. 2012-057622 includes a reed valve that is installed at a
discharge port. The discharge port is opened and closed by
deflecting the reed valve by a discharge pressure of the gas. In
Japanese Laid-Open Patent Publication No. 2012-057622, it is also
described that the reed valve is formed with a leaf spring which
includes a single plate or a laminated plate.
[0003] In the above vane type vacuum pump, the reed valve sometimes
resonates due to disturbance of a flow of the gas that is
discharged from the discharge port. When the reed valve resonates,
a pulsation occurs in the gas discharged from the discharge port.
Then, by the pulsation of the gas, a pressure variation occurs in
the installation space of the vane type vacuum pump. A wall surface
of the installation space vibrates due to the pressure variation,
and vibration energy of the wall surface vibration is radiated to
an outer side as sound, and abnormal noise occurs.
SUMMARY OF THE INVENTION
[0004] The vane type vacuum pump includes a first reed valve that
is installed at the discharge port, and a second reed valve that is
superposed with the first reed valve and has a resonance frequency
which is different from that of the first reed valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a front view of a vane type vacuum pump according
to a first embodiment of the present invention;
[0006] FIG. 2 is a perspective view of a reed valve part;
[0007] FIG. 3 is an exploded perspective view of the reed valve
part;
[0008] FIG. 4A is a sectional view showing a state that the reed
valve part is closed;
[0009] FIG. 4B is a sectional view showing a state that the reed
valve part is opened;
[0010] FIG. 5A is a plan view of a first reed valve that configures
a reed valve part of a vane type vacuum pump according to a second
embodiment of the present invention;
[0011] FIG. 5B is a plan view of a second reed valve that
configures the reed valve part;
[0012] FIG. 6A is a plan view of a first reed valve that configures
a reed valve part of a vane type vacuum pump according to another
example;
[0013] FIG. 6B is a plan view of a second reed valve that
configures the reed valve part;
[0014] FIG. 7A is a plan view of a first reed valve that configures
a reed valve part of a vane type vacuum pump according to another
example;
[0015] FIG. 7B is a plan view of the second reed valve that
configures the reed valve part;
[0016] FIG. 8A is a plan view of a first reed valve that configures
a reed valve part of a vane type vacuum pump according to a third
embodiment of the present invention; and
[0017] FIG. 8B is a plan view of a second reed valve that
configures the reed valve part.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0018] Hereinafter, a vane type vacuum pump according to a first
embodiment of the present invention will be described in detail
with reference to FIGS. 1 to 4B.
[0019] The vane type vacuum pump is installed inside a cylinder
head of an engine in a state that a lower portion is soaked in oil.
The vane type vacuum pump is coupled to a camshaft. When the
camshaft has rotated, the vane type vacuum pump suctions air from a
negative pressure actuator such as a brake booster, and discharges
the air within the cylinder head.
[0020] As shown in FIG. 1, the vane type vacuum pump has a
discharge port 10 for discharging the suctioned air, and a reed
valve part 11 that opens and closes the discharge port 10. In a
state that the vane type vacuum pump is installed within the
cylinder head cover, the discharge port 10 is laid out at a
slightly higher side than the liquid surface of the oil.
[0021] As shown in FIGS. 2 and 3, the reed valve part 11 includes a
first reed valve 12, a second reed valve 13, and a stopper member
14. At right side end parts of the first reed valve 12, the second
reed valve 13, and the stopper member 14, through-holes 12c, 13c,
and 14c are formed, respectively. The first reed valve 12, the
second reed valve 13, and the stopper member 14 are superposed with
each other in this order from the discharge port 10 side. At the
lateral side of the discharge port 10, a screw hole 15 is formed.
The first reed valve 12, the second reed valve 13, and the stopper
member 14 are fitted to a pump body 17, by fastening a bolt 16 that
has pierced through the through-holes 12c, 13c, and 14c, with the
screw hole 15.
[0022] The first reed valve 12 and the second reed valve 13 have
the same materials and the same planar shapes, but have different
thicknesses. In FIG. 3, the thickness of the second reed valve 13
is shown larger than the thickness of the first reed valve 12.
However, the thickness of the first reed valve 12 may be larger
than the thickness of the second reed valve 13.
[0023] The first reed valve 12 and the second reed valve 13 include
fixed portions 12a and 13a, and valve body portions 12b and 12b.
The fixed portions 12a and 13a are portions that are fixed to the
pump body 17 with the bolt 16. The valve body portions 12b and 13b
are elastically deformable portions in the first reed valve 12 and
the second reed valve 13. The valve body portions 12b and 13b have
shapes and sizes that cover a whole opening of the discharge port
10. The valve body portion 12b of the first reed valve 12 is
brought into contact with a valve seat 18 that is provided at the
peripheral edge of the opening of the discharge port 10. The first
reed valve 12 and the second reed valve 13 are superposed with each
other in a state that the valve body portions 12b and 13b are
slide-contacted with each other.
[0024] The stopper member 14 is made of metal, and has a larger
thickness than the thicknesses of the first reed valve 12 and the
second reed valve 13. The stopper member 14 has a first end part
that is fixed to the bolt 16, and a second end part located
opposite to the first end part. The stopper member 14 is curved so
as to be separated from the discharge port 10 as the stopper member
14 proceeds from the first end part to the second end part.
[0025] An operation of the reed valve part 11 of the vane type
vacuum pump will be described with reference to FIGS. 4A and
4B.
[0026] During the operation of the vane type vacuum pump, air is
intermittently discharged from the discharge port 10. The reed
valve part 11 operates to open the discharge port 10 during
discharge of the air, and close the discharge port 10 during
non-discharge of the air.
[0027] In the state shown in FIG. 4A, the valve body portion 12b of
the first reed valve 12 is in contact with the valve seat 18, and
the opening of the discharge port 10 is closed. As shown in FIG.
4B, when the air starts being discharged from the discharge port
10, the valve body portion 12b of the first reed valve 12 is curved
and deflected and the valve body portion 13b of the second reed
valve 13 that is brought into contact with the valve body portion
12b is also curved and deflected, by the pressure of the air.
Accordingly, the valve body portion 12b of the first reed valve 12
is separated from the valve seat 18, and the discharge port 10 is
opened.
[0028] When the inverse number of the cycle of opening and closing
the discharge port 10 becomes close to the intrinsic vibration
frequencies of the first reed valve 12 and the second reed valve
13, the first reed valve 12 and the second reed valve 13 resonate.
When the first reed valve 12 and the second reed valve 13 resonate
simultaneously, a pulsation occurs in the air that is discharged
from the discharge port 10. Then, a pressure variation occurs in
the space within the cylinder head cover in which the vane type
vacuum pump is installed. The wall surface of the cylinder head
cover vibrates due to the pressure variation, the vibration energy
is radiated to the outer side as sound, and abnormal noise
occurs.
[0029] In this respect, according to the vane type vacuum pump of
the first embodiment, the first reed valve 12 and the second reed
valve 13 have different resonance frequencies because they have
different thicknesses. Therefore, the first reed valve 12 and the
second reed valve 13 do not resonate simultaneously. Accordingly,
even when one of the first reed valve 12 and the second reed valve
13 resonates, the vibration is suppressed by the other reed valve
that does not resonate. Consequently, a vibration amplitude during
resonance becomes smaller.
[0030] Further, at the time of opening and closing the discharge
port 10, a relative sliding occurs between contact surfaces of the
first reed valve 12 and the second reed valve 13 that are
superposed with each other. Therefore, according to the vane type
vacuum pump of the first embodiment, vibrations of the first reed
valve 12 and the second reed valve 13 are attenuated by the
friction between the contact surfaces due to relative sliding.
[0031] The stopper member 14 regulates the opening of the first
reed valve 12 and the second reed valve 13 not to exceed a constant
amount of opening. Therefore, even when a discharge pressure of the
air from the discharge port 10 has become excessively large,
excessive opening of the first reed valve 12 and the second reed
valve 13 can be regulated.
[0032] According to the vane type vacuum pump of the first
embodiment, the following advantages can be obtained.
[0033] (1) According to the vane type vacuum pump, the first reed
valve and the second reed valve are deflected by the discharge
pressure of the gas so that the discharge port is opened and
closed. When the inverse number of the cycle of opening and closing
the discharge port becomes close to the resonance frequency of the
first reed valve and the second reed valve, the first reed valve
and the second reed valve resonate. In this respect, according to
the vane type vacuum pump of the first embodiment, the reed valve
that opens and closes the discharge port 10 is configured as
follows. That is, the reed valve is configured by superposing the
first reed valve 12 and the second reed valve 13 that have
different resonance frequencies. According to this configuration,
because the first reed valve 12 and the second reed valve 13 have
different resonance frequencies, the first reed valve 12 and the
second reed valve 13 do not resonate simultaneously. Accordingly,
even when one of the first reed valve 12 and the second reed valve
13 resonates, the vibration is regulated by the other reed valve
that does not resonate. As a result, resonance of the reed valve
that becomes the cause of the abnormal noise can be suppressed.
[0034] (2) Therefore, vibrations of the first reed valve 12 and the
second reed valve 13 are attenuated by friction between the contact
surfaces of the first reed valve 12 and the second reed valve 13.
As a result, resonance of the reed valves can be suppressed.
[0035] (3) At the outer side of the first reed valve 12 and the
second reed valve 13, the stopper member 14 is provided to limit a
valve open amount of the first reed valve 12 and the second reed
valve 13. Therefore, it is possible to suppress excessive
deformation of the first reed valve 12 and the second reed valve 13
and remaining of the deformation in the reed valve.
[0036] (4) Simply differentiating the thicknesses of the first reed
valve 12 and the second reed valve 13 makes it possible to easily
differentiate the resonance frequencies of the first reed valve 12
and the second reed valve 13. For example, in the case of stamping
the first reed valve 12 and the second reed valve 13, it is
possible to manufacture the first reed valve 12 and the second reed
valve 13 by using the same stamping mold, by simply changing the
thicknesses of metal materials.
Second Embodiment
[0037] Next, a vane type vacuum pump according to a second
embodiment of the present invention will be described with
reference to FIGS. 5A to 7B. In describing the second embodiment,
configurations that are common to the first embodiment are attached
with the same symbols, and their detailed descriptions will be
omitted.
[0038] As shown in FIGS. 5A and 5B, the vane type vacuum pump of
the second embodiment uses two reed valves. A first reed valve 21
shown in FIG. 5A is installed so as to be in contact with the valve
seat 18 surrounding the discharge port 10 shown in FIG. 2. A second
reed valve 22 shown in FIG. 5B is superposed on the first reed
valve 21 in a state that valve body portions of the first and
second reed valves 21 and 22 can be slide-contacted with each
other. Although the first reed valve 21 and the second reed valve
22 have the same materials and the same thicknesses, the first reed
valve 21 and the second reed valve 22 have different planar
shapes.
[0039] In the case of FIGS. 5A and 5B, the valve body portion of
the second reed valve 22 is formed smaller than the valve body
portion of the first reed valve 21.
[0040] In the second embodiment, the first reed valve 21 and the
second reed valve 22 also have different resonance frequencies by
having different planar shapes. Therefore, the first reed valve 21
and the second reed valve 22 do not resonate simultaneously, and
resonance of the reed valve that becomes the cause of abnormal
noise can be suppressed. Consequently, the advantages described in
the above (1) to (3) can be also obtained by the vane type vacuum
pump of the second embodiment.
[0041] In the example shown in FIGS. 5A and 5B, by setting the
valve body portion of the second reed valve 22 to be smaller than
the valve body portion of the first reed valve 21, shapes of both
reed valves have been differentiated. However, shapes of both reed
valves may be differentiated by the following mode.
[0042] As shown in FIGS. 6A and 6B, by setting the valve body
portion of a second reed valve 24 to be larger than the valve body
portion of a first reed valve 23, resonance frequencies of both
reed valves may be differentiated.
[0043] As shown in FIGS. 7A and 7B, by forming a hole 27 in one of
valve body portions of a first reed valve 25 and a second reed
valve 26, resonance frequencies of both reed valves may be
differentiated. In FIG. 7B, the hole 27 is formed on the second
reed valve 26. Further, by forming holes on both the first and
second reed valves and by differentiating shapes, sizes, and
numbers of the holes, resonance frequencies of both reed valves may
be differentiated.
Third Embodiment
[0044] Next, a vane type vacuum pump according to a third
embodiment of the present invention will be described with
reference to FIGS. 8A and 8B. In describing the third embodiment,
configurations that are common to the above embodiments are
attached with the same symbols, and their detailed descriptions
will be omitted.
[0045] As shown in FIGS. 8A and 8B, the vane type vacuum pump of
the third embodiment uses two reed valves. A first reed valve 28
shown in FIG. 8A is installed so as to be in contact with the valve
seat 18 surrounding the discharge port 10. A second reed valve 29
shown in FIG. 8B is superposed on the first reed valve 28 in a
state that valve body portions of the first and second reed valves
21 and 22 can be slide-contacted with each other. Although the
first reed valve 28 and the second reed valve 29 have the same
sizes and the same shapes, these reed valves are respectively
formed with different materials.
[0046] In the third embodiment, the first reed valve 28 and the
second reed valve 29 also have different resonance frequencies by
being formed with different materials. Therefore, the first reed
valve 28 and the second reed valve 29 do not resonate
simultaneously, and resonance of the reed valve that becomes the
cause of abnormal noise can be suppressed. Consequently, the
advantages described in the above (1) to (3) can be also obtained
by the vane type vacuum pump of the third embodiment.
[0047] The above embodiment may be changed as follows.
[0048] Shapes of the first and second reed valves and the stopper
member may be changed to match the shape of the discharge port of
the vane type vacuum pump that is applied.
[0049] The stopper member 14 may be omitted.
[0050] By differentiating two or all of thicknesses, shapes, and
materials of the first and second reed valves, resonance
frequencies of both reed valves may be differentiated.
[0051] In the above embodiments, although the first and second reed
valves are different members, both reed valves may be integrally
formed when the valve body portions can be slide-contacted with
each other. For example, by folding one plate material into two
portions, the reed valve may be configured such that two valve body
portions are superposed to be able to be slide-contacted with each
other.
* * * * *