CN115638106A - Vacuum pump - Google Patents

Abstract

Provided is a vacuum pump capable of suppressing sticking of a valve element to a valve seat due to backflow generated at the end of the operation of the vacuum pump. The vacuum pump (1) has: a pump chamber (4); an exhaust flow path (6), which has an exhaust port (5) connected to the atmosphere, and is used to guide the exhaust from the pump chamber (4) to the atmosphere; a valve The core (8), which is arranged in the exhaust flow path (6), can be seated on the valve seat (15) formed in the exhaust flow path (6); the stopper (10), which is arranged in the exhaust flow Road (6), used to limit the position of the valve core (8) in the exhaust flow path (6) when the valve core (8) is not seated; 10) The restricted position of the valve core (8) and the valve seat (15) are connected with the exhaust flow path (6), and the other end is connected with the atmospheric communication port (20), and the atmospheric communication port (20) is connected with the exhaust port (5) Separately communicated with the atmosphere.

Description

vacuum pump

technical field

The present disclosure relates to a vacuum pump.

Background technique

Currently, in vehicles such as automobiles, a vacuum pump is sometimes used to create a negative pressure in a negative pressure chamber of a brake booster. The vacuum pump is often installed in the engine room of the vehicle, but it may be installed in a position close to the ground in some cases. Therefore, depending on where it is assembled, the vacuum pump may become flooded when the vehicle is driven through a deep puddle. To address this problem, Patent Document 1 discloses a vacuum pump including a valve element capable of closing an exhaust port (valve seat) of an exhaust flow path.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2020-097912

Contents of the invention

(1) Technical problems to be solved

However, when the vacuum pump ends (immediately after the pump power is turned off), since the pump chamber and the anechoic chamber are under negative pressure, atmospheric pressure is restored to the pump chamber by sucking air from the exhaust port. Therefore, immediately after the power supply to the pump is stopped, a reverse flow that flows toward the pump chamber in the exhaust flow path occurs. However, in the technique described in Patent Document 1, the valve element may be sucked into the valve seat due to backflow, and may stick to the valve seat. Furthermore, if water droplets adhering to the valve seat or the valve body freeze when the valve body is attached to the valve seat, the valve seat may not be able to open.

The present disclosure has been made in view of the above-mentioned technical problems, and an object thereof is to provide a vacuum pump capable of suppressing sticking of a valve element to a valve seat due to backflow generated when the operation of the vacuum pump ends.

(2) Technical solutions

(1) The vacuum pump according to at least one embodiment of the present disclosure includes: a pump chamber; an exhaust flow path, which has an exhaust port communicated with the atmosphere, and is used to guide the exhaust from the pump chamber to the atmosphere; In the exhaust flow path, it can be seated on the valve seat formed in the exhaust flow path; the stopper, which is arranged in the exhaust flow path, is used to limit the position of the valve core in the exhaust flow path when the valve core is not seated. position within; and the atmospheric communication path, one end of which is communicated with the exhaust flow path between the limit position of the stopper to the valve core and the valve seat, and the other end is communicated with the atmospheric communication port, and the atmospheric communication port is separated from the exhaust port. connected to the atmosphere.

(2) In some embodiments, in the structure described in (1) above, the exhaust flow path may include a cylindrical member having a first end forming a valve seat and forming an exhaust valve. The second end of the port communicates with the inner space of the cylindrical member through an opening radially penetrating the cylindrical member at one end of the atmosphere communication passage.

(3) In some embodiments, in the structure described in (2) above, a main body may be further provided, the main body has an insertion hole for inserting a cylindrical member, and a cylindrical member is formed on the inner wall of the insertion hole. Opposite the opening of the part, the slot extends into the open end of the insertion bore.

(4) In some embodiments, in the structure described in (2) or (3) above, it may be that the opening is at least partially aligned with the valve core at the restricting position of the stopper in the axial direction of the cylindrical member. The overlapping pattern is formed closer to the valve seat side than the center of the valve element.

(5) In some embodiments, in the structure described in (2) or (3) above, the valve element may have a spherical shape, and the opening may have a shape through which the valve element cannot pass.

(3) Beneficial effects

According to the vacuum pump of the present disclosure, it is possible to suppress the sticking of the valve element to the valve seat due to backflow generated when the operation of the vacuum pump ends.

Description of drawings

FIG. 1 is a schematic exploded perspective view showing a vacuum pump according to one embodiment.

Fig. 2 is a partially cutaway sectional view of the vacuum pump shown in Fig. 1 .

Fig. 3A is a diagram for explaining the function of the spool.

Fig. 3B is a diagram for explaining the function of the spool.

FIG. 3C is a diagram for explaining the operation of the valve element immediately after the operation of the vacuum pump is completed.

FIG. 4 is a schematic configuration diagram showing the configuration of an atmosphere communication passage according to an embodiment.

Fig. 5 is a cross-sectional view along line A-A of Fig. 4 .

FIG. 6 is a schematic configuration diagram showing the configuration of an atmosphere communication passage in some embodiments.

Fig. 7 is a schematic configuration diagram showing the configuration of an atmosphere communication passage in some embodiments.

FIG. 8 is a diagram showing the shape of openings according to one embodiment.

Fig. 9 is a diagram showing the shape of openings in some embodiments.

Fig. 10 is a diagram showing the shape of openings in some embodiments.

Fig. 11 is a schematic configuration diagram showing the configuration of an atmosphere communication passage in some embodiments.

Explanation of reference signs

1-vacuum pump; 4-pump chamber; 5-exhaust port; 6-exhaust flow path; 8-valve core; 10-stopper; 12-atmosphere communication path; 16-the first end of the cylindrical component; 18-the second end of the cylindrical component; 20-atmospheric communication port; 22-one end of the atmospheric communication channel; 24-the other end of the atmospheric communication channel; 25-inner space; 27-opening; 30-groove; 68-exhaust cover (main body); 70-insertion hole; 71-inner wall; 73-opening end.

Detailed ways

Embodiments of the vacuum pump of the present disclosure will be described below with reference to the drawings. However, dimensions, materials, shapes, relative arrangements, and the like of components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" indicating relative or absolute configurations are not only Strictly referring to such an arrangement also refers to a state of being relatively displaced by a tolerance or an angle and a distance to the extent that the same function can be obtained.

For example, expressions such as "same", "equal", and "homogeneous" indicating that things are in an equal state not only strictly indicate an equal state, but also indicate a state in which there is a difference in the degree of tolerance or the same function can be obtained.

For example, an expression indicating a shape such as a square shape or a cylindrical shape does not mean only a shape such as a square shape or a cylindrical shape in a strict geometric sense, but also means that a concave-convex portion, a chamfered portion, etc. are included within the range where the same effect can be obtained. shape.

On the other hand, the expression "exists", "has", "has", "includes" or "has" one constituent element is not an exclusive expression excluding the existence of other constituent elements.

FIG. 1 is a schematic exploded perspective view showing a vacuum pump 1 according to one embodiment. FIG. 2 is a partially cutaway sectional view of the vacuum pump 1 shown in FIG. 1 . The vacuum pump 1 illustrated in FIGS. 1 and 2 is an electric vacuum pump for making negative pressure in a negative pressure chamber of a brake booster (Master vac) of a vehicle such as an automobile. Hereinafter, "upper" and "lower" represent "upper" and "lower" in the state where the vacuum pump 1 is installed in the vehicle, and will be described. In the present disclosure, in the rotation axis direction of the rotor 56 described later, the top cover 64 side is set as “up”, and the motor 100 side is set as “down” to define up and down.

A vacuum pump 1 according to one embodiment will be described. As shown in FIGS. 1 and 2 , the vacuum pump 1 includes a pump chamber 4 , an exhaust flow path 6 , a valve body 8 , a stopper 10 , and an atmosphere communication path 12 .

A movable part 50 for sucking gas into the pump chamber 4 and discharging gas from the pump chamber 4 is accommodated in the pump chamber 4 . In the form shown in FIGS. 1 and 2 , the movable portion 50 is driven by a motor 100 as a driving device. The movable portion 50 includes a rotor 56 having a plurality of slits 54 formed in an outer peripheral surface 52 , and a plurality of vanes 58 arranged in the plurality of slits 54 , respectively. In this way, the vacuum pump 1 is configured as a vane-type electric vacuum pump. The rotor 56 is coupled to an unillustrated shaft of the motor 100 and rotates around the shaft. When the rotor 56 rotates, the vane 58 moves radially outward along the slit 54 of the rotor 56 by centrifugal force, and the front end 59 of the vane 58 slides on the wall surface (cam surface 51 ) of the pump chamber 4 .

In the form illustrated in FIGS. 1 and 2 , the vacuum pump 1 includes a pump casing body 60 , a pump cover 62 , a top cover 64 and a bottom cover 66 . The bottom cover 66 , the pump casing body 60 , the pump cover 62 , and the top cover 64 are arranged in this order from the bottom.

The pump casing body 60 defines the pump chamber 4 accommodating the movable part 50 . The pump chamber 4 includes a cam surface 51 opposed to the outer peripheral surface 52 of the rotor 56 . The pump casing body 60 includes an exhaust cover portion 68 (main body) covering the periphery of a cylindrical member 14 described later in the exhaust flow path 6 . The exhaust cap portion 68 has a cylindrical shape and extends in the vertical direction. An insertion hole 70 , which is open to outside air and through which the cylindrical member 14 is inserted, is formed on the lower end surface of the exhaust cap portion 68 .

The pump cover 62 is provided independently of the pump casing body 60 and covers one side of the movable part 50 (the upper side of the rotor 56 in the illustrated form). The pump cover 62 includes an air intake port 74 configured to allow air to flow into the pump chamber 4 from an air intake passage 72 for introducing air into the pump chamber 4 . The pump cover 62 is constituted as an independent member detachable from the pump casing main body 60, and is fastened to the pump casing main body 60 by bolts 76 (see FIG. 1 ) as fastening members.

The top cover 64 covers the upper side of the pump cover 62 . The top cover 64 is provided separately from the pump cover 62 . The top cover 64, the pump cover 62, and the pump casing body 60 are fastened together by bolts 78 (see FIG. 1 ) as fastening members.

The bottom cover 66 is provided between the pump casing body 60 and the motor 100 and covers the lower side of the pump casing body 60 . The bottom cover 66 includes an air intake pipe portion 80 for inhaling air from a negative pressure chamber of a brake booster (not shown). The air intake passage 72 described above takes in gas through the air intake pipe portion 80 . The bottom cover 66 is provided separately from the pump housing body 60 . The bottom cover 66 is fastened to the pump casing main body 60 by bolts 82 (see FIG. 1 ) as fastening members.

Next, the exhaust flow path 6 will be described. The exhaust flow path 6 has an exhaust port 5 communicating with the atmosphere, and guides exhaust from the pump chamber 4 to the atmosphere. In the manner illustrated in FIG. 2 , the exhaust flow path 6 includes: an anechoic chamber 84 (expansion chamber) as an expansion type sound absorber formed between the pump casing body 60 and the bottom cover 66; chamber) as an expansion-type sound absorber formed between the pump cover 62 and the top cover 64; The exhaust flow path 6 includes an anechoic chamber 84 , an anechoic chamber 86 , and a tubular member 14 in order from the upstream side along the flow direction in which exhaust gas flows in the exhaust flow path 6 .

Exhaust gas from the pump chamber 4 is discharged to the muffler chamber 84 through a discharge port 88 formed in the pump casing main body 60 . The exhaust gas that has passed through the muffler chamber 84 flows into the muffler chamber 86 through the through hole 90 that penetrates the pump casing main body 60 and the pump cover 62 . The space in the anechoic chamber 86 and the space in the cylindrical member 14 communicate with each other, and the exhaust gas that has passed through the anechoic chamber 86 flows into the cylindrical member 14 .

In the form illustrated in FIG. 2 , the cylindrical member 14 is provided separately from the pump cover 62 and the exhaust cover portion 68 of the pump casing body 60 . The cylindrical member 14 is inserted from the insertion hole 70 of the exhaust cover portion 68 , and is mounted on the vacuum pump 1 by pressing the upper end portion of the cylindrical member 14 into the hole 53 formed in the pump cover 62 .

The cylindrical member 14 has a first end 16 forming the valve seat 15 and a second end 18 forming the exhaust port 5 . The exhaust port 5 is located below the valve seat 15 . In the form illustrated in FIG. 2 , the first end 16 includes a tapered surface 92 that expands in cross-section as the flow path of the cylindrical member 14 goes downward. The tapered surface 92 functions as a valve seat 15 on which a valve body 8 described later can be seated. The second end portion 18 includes a straight surface 94 extending straight from the lower end of the tapered surface 92 toward the exhaust port 5 .

The valve body 8 is provided in the exhaust flow path 6 and can be seated on a valve seat 15 formed in the exhaust flow path 6 . In the form illustrated in FIG. 2 , the spherical valve body 8 is installed in the cylindrical member 14 . The inner diameter of the second end portion 18 of the cylindrical member 14 is larger than the diameter of the spool 8 . That is, fluid can communicate between the valve body 8 and the straight surface 94 of the second end portion 18 of the cylindrical member 14 .

The stopper 10 is provided on the exhaust flow path 6 and restricts the position of the valve element 8 in the exhaust flow path 6 when the valve element 8 is not seated. Furthermore, the stopper 10 is configured to allow the exhaust gas flowing through the exhaust flow path 6 to pass therethrough. Such a stopper 10 may be, for example, a net-like member configured in a net shape, or may be a clip formed by bending a wire.

Here, the function of the spool 8 will be described. 3A and 3B are views for explaining the function of the valve body 8, respectively. FIG. 3C is a diagram for explaining the operation of the valve body 8 immediately after the operation of the vacuum pump 1 is completed.

The valve element 8 is configured to be able to switch the state of the valve seat 15 , for example, an open state shown in FIG. 3A and a closed state shown in FIG. 3B . The open state is a state in which the vacuum pump 1 is operated, the valve element 8 is separated from the valve seat 15, and the space in the cylindrical member 14 communicates with the outside air. The spool 8 is supported by the stopper 10 so as not to fall off from the cylindrical member 14 . The closed state is a state in which the vacuum pump 1 is immersed in water, and the valve core 8 closes the valve seat 15 by the buoyancy of the valve core 8 . In this way, even when the vacuum pump 1 is submerged in water, the valve body 8 closes the valve seat 15 to prevent water from entering the pump chamber 4 through the valve seat 15 .

However, when the operation of the vacuum pump 1 ends, since the inside of the pump chamber 4 and the anechoic chambers 84 and 86 are under negative pressure, external air is sucked in from the exhaust port 5 to return the inside of the pump chamber 4 to atmospheric pressure. Therefore, a reverse flow X flowing toward the pump chamber 4 in the exhaust flow path 6 is generated. As shown in FIG. 3C , the valve core 8 is sucked into the valve seat 15 due to the generation of the reverse flow X, and may be attached to the valve seat 15 . Furthermore, if the water droplets adhering to the valve body 8 or the valve seat 15 freeze while the valve body 8 is attached to the valve seat 15, the valve seat 15 may not be able to open.

In order to solve such a problem, a vacuum pump 1 according to an embodiment of the present disclosure includes an atmosphere communication passage 12 . FIG. 4 is a schematic configuration diagram showing the configuration of the atmosphere communication passage 12 according to one embodiment. Fig. 5 is a cross-sectional view along line A-A of Fig. 4 .

One end 22 of the atmosphere communication path 12 communicates with the exhaust flow path 6 between the limit position of the stopper 10 to the valve core 8 and the valve seat 15, and the other end 24 communicates with the atmosphere communication port 20, which is connected to the exhaust gas communication port 20. The air port 5 communicates separately with the atmosphere. In the form illustrated in FIG. 4 , one end 22 of the atmosphere communication passage 12 communicates with the internal space 25 of the cylindrical member 14 via an opening 27 penetrating the cylindrical member 14 in the radial direction. The opening 27 is located between the stopper 10 and the valve seat 15 in the vertical direction (flow direction of exhaust gas). The other end 24 of the atmosphere communication path 12 communicates with the atmosphere communication port 20 formed on the outer peripheral surface 69 of the exhaust cap portion 68 . The atmosphere communication port 20 is formed by a through hole 21 that passes through the outer peripheral surface 69 of the exhaust cap portion 68 to the insertion hole 70 . The through hole 21 is, for example, a slit obtained by cutting out the outer peripheral surface 69 of the exhaust cap portion 68 .

In one embodiment, as shown in FIG. 4 , a gap 75 is formed between the outer wall 17 of the cylindrical member 14 and the inner wall 71 of the insertion hole 70 . The opening 27 of the cylindrical member 14 communicates with the through hole 21 of the exhaust cap portion 68 via the gap 75 . That is, in the form illustrated in FIG. 4 , the atmosphere communication passage 12 is formed by the opening 27 of the cylindrical member 14 , the gap 75 , and the through hole 21 of the exhaust cap portion 68 . In some embodiments, the gap 75 is not provided, and the opening 27 of the cylindrical member 14 may directly communicate with the through hole 21 of the exhaust cap portion 68 .

According to such a configuration, since the atmosphere communication passage 12 bypassing the exhaust port 5 is formed, part or all of the outside air sucked in when the operation of the vacuum pump 1 ends flows through the atmosphere communication passage 12 . Therefore, it is possible to reduce the flow rate of the flow of outside air (backflow X) from the exhaust port 5 toward the valve seat 15 . Therefore, the suction force (the flow rate of the reverse flow X) acting on the valve body 8 can be reduced, and the sticking of the valve body 8 to the valve seat 15 can be suppressed. In addition, the atmosphere communication passage 12 and the exhaust flow passage 6 can communicate with each other by a simple structure using a member such as the cylindrical member 14 .

In one embodiment, as shown in FIG. 4 , the opening 27 of the cylindrical member 14 is at least partially overlapped with the valve core 8 at the restricting position of the stopper 10 in the vertical direction (the axial direction of the cylindrical member 14 ). The mode is formed on the side closer to the valve seat 15 than the center O of the valve element 8 .

According to such a structure, it is possible to suppress the lift of the valve body 8 caused by the flow taken into the cylindrical member 14 from the atmosphere communication passage 12 through the opening 27 of the cylindrical member 14, and by making the opening 27 of the cylindrical member 14 The position is far away from the valve seat 15, and it is possible to suppress the adhesion of foreign matter entering through the opening 27 of the cylindrical member 14 to the valve seat 15.

In one embodiment, as shown in FIG. 5 , three through-holes 21 ( 21 a , 21 b , and 21 c ) are formed in the exhaust cover portion 68 . The first through-hole 21 a penetrates a portion P of the outer peripheral surface 69 of the exhaust cover portion 68 that is farthest from the pump chamber 4 when viewed from the up-down direction. The second through-hole 21 b opens at 90 degrees on one side in the circumferential direction of the cylindrical member 14 with respect to the opening direction D1 of the first through-hole 21 a. The third through-hole 21c is opened on the other side in the circumferential direction of the cylindrical member 14 by 90 degrees with respect to the opening direction D1 of the first through-hole 21a. That is, the second through-hole 21b and the third through-hole 21c are opened in directions opposite to each other.

In one embodiment, as shown in FIG. 5 , three openings 27 ( 27 a , 27 b , 27 c ) are formed in the cylindrical member 14 . The first opening 27a faces the first through hole 21a. At least a part of the opening surface of the first opening 27a is connected to the opening surface of the first through hole 21a (atmospheric communication port 20 ) when viewed in a direction perpendicular to the axial direction of the cylindrical member 14 (hereinafter referred to as "radial view"). overlapping. Likewise, the second opening 27b is opposed to the second through hole 21b. At least a part of the opening surface of the second opening 27b overlaps with the opening surface of the second through hole 21b when viewed in the radial direction. The third opening 27c is opposite to the third through hole 21c. At least a part of the opening surface of the third opening 27c overlaps with the opening surface of the third through hole 21c when viewed in the radial direction.

According to the configuration illustrated in FIG. 5 , by making the opening 27 face the through hole 21 , the flow of the fluid in the atmosphere communication path 12 can be improved, and the flow of outside air from the exhaust port 5 toward the valve seat 15 when the operation of the vacuum pump 1 is completed can be further reduced. The flow rate of the flow (counterflow X).

However, the structure of the atmosphere communication passage 12 is not limited to the form shown in FIG. 4 . 6 and 7 are schematic configuration diagrams showing the configuration of the atmosphere communication passage 12 in some embodiments, respectively.

In the form illustrated in FIG. 6 , an opening extending from a position P1 opposing the opening 27 of the cylindrical member 14 to the insertion hole 70 is formed on the inner wall 71 of the insertion hole 70 formed in the exhaust cap portion 68 (main body). end 73 of the groove 30. This position P1 overlaps with the opening 27 of the cylindrical member 14 in the vertical direction. More specifically, this position P1 is located at the same height as the upper end 77 inside the wall surface forming the opening 27 of the cylindrical member 14 in the vertical direction. Thus, in the form illustrated in FIG. 6 , the atmosphere communication path 12 is formed by the opening 27 of the cylindrical member 14 , the gap 75 , and the groove 30 of the exhaust cap portion 68 . In some embodiments, the gap 75 is not provided, and the atmosphere communication path 12 may be formed by the opening 27 of the cylindrical member 14 and the groove 30 of the exhaust cap portion 68 .

In the form illustrated in FIG. 7 , the opening 29 ( 27 ) penetrates through the lower end of the cylindrical member 14 . Such an opening 29 is, for example, a slit formed by cutting out the outer wall 17 of the cylindrical member 14 . The opening 29 faces the inner wall 71 of the insertion hole 70 via the gap 75 . That is, in the form illustrated in FIG. 7 , the atmosphere communication path 12 is formed by the opening 29 of the cylindrical member 14 , the gap 75 , and the inner wall 71 of the insertion hole 70 . In some embodiments, the gap 75 is not provided, and the atmosphere communication path 12 may be formed by the opening 29 of the cylindrical member 14 and the inner wall 71 of the insertion hole 70 .

According to the structures illustrated in FIGS. 6 and 7 , by inserting the cylindrical member 14 into the insertion hole 70 of the exhaust cap portion 68 , the atmosphere communication passage 12 can be formed.

Next, the configuration of the opening 27 of the cylindrical member 14 according to one embodiment will be described. FIG. 8 is a diagram showing the shape of the opening 27 according to one embodiment. 9 and 10 are diagrams showing the shape of the opening 27 of some embodiments, respectively. In each of FIGS. 8 to 10 , the spool 8 is indicated by a dotted line.

As mentioned above, the spool 8 of one embodiment has a spherical shape. Furthermore, the opening 27 of the cylindrical member 14 has a shape in which the valve body 8 cannot pass through. Specifically, as shown in FIG. 8 , the opening 27 of the cylindrical member 14 has a circular shape when viewed in the radial direction. Assuming that the diameter of the opening 27 is D1 and the diameter of the spool 8 is D2, D1<D2 is satisfied. According to such a configuration, it is possible to suppress the valve body 8 from slipping out of the cylindrical member 14 through the opening 27 of the cylindrical member 14 .

In some embodiments, as illustrated in FIGS. 9 and 10 , respectively, the opening 27 of the cylindrical member 14 has an oval shape. In the form illustrated in FIG. 9 , the opening 27 has a longitudinal direction along a horizontal direction perpendicular to the vertical direction, and has, for example, a raceway shape. When the size of the width direction of the opening 27 is D3, D3<D2 is satisfied. In the form illustrated in FIG. 10 , the opening of the cylindrical member 14 , that is, the opening 27 has a longitudinal direction along the vertical direction. When the size of the width direction of the opening 27 is D4, D4<D2 is satisfied.

As mentioned above, although the vacuum pump 1 of some embodiment of this disclosure was demonstrated, this disclosure is not limited to the above-mentioned form, Various changes are possible in the range which does not deviate from the objective of this disclosure.

In the above-described embodiment, the vacuum pump 1 includes the independently formed cylindrical member 14, but the present invention is not limited to this form. FIG. 11 is a schematic configuration diagram showing the configuration of the atmosphere communication passage 12 in some embodiments. In the embodiment illustrated in FIG. 11 , the insertion hole 70 of the exhaust cap portion 68 forms the exhaust port 5 of the exhaust flow path 6 that communicates with the atmosphere. In addition, the exhaust cap portion 68 includes a protruding portion 96 (stopper 10 ) protruding inwardly from the inner wall 71 of the insertion hole 70 . This protruding portion 96 supports the valve body 8 from below. The pump cover 62 includes a valve seat portion 98 that forms the valve seat 15 by being inserted into the insertion hole 70 of the exhaust cover portion 68 from above. Furthermore, in the form illustrated in FIG. 11 , the atmosphere communication passage 12 is formed by penetrating the outer peripheral surface 69 of the exhaust cap portion 68 to the insertion hole 70 .

Claims (5)

1. A vacuum pump, which has: pump room; an exhaust flow path, which has an exhaust port communicated with the atmosphere, and is used to guide the exhaust from the pump chamber to the atmosphere; a valve core, which is arranged in the exhaust flow path and can be seated on a valve seat formed in the exhaust flow path; a stopper, which is provided in the exhaust flow path, for limiting the position of the valve core in the exhaust flow path when the valve core is not seated; and An atmospheric communication passage, one end of which communicates with the exhaust flow passage between the position where the stopper restricts the valve core and the valve seat, and the other end communicates with the atmospheric communication port, which communicates with the atmospheric communication port The exhaust ports are separately communicated with the atmosphere. 2. The vacuum pump according to claim 1, characterized in that, The exhaust flow path includes a cylindrical member having a first end forming the valve seat and a second end forming the exhaust port, The one end of the atmosphere communication path communicates with the inner space of the cylindrical member through an opening radially penetrating the cylindrical member. 3. The vacuum pump according to claim 2, characterized in that, A main body is further provided, and the main body has an insertion hole into which the cylindrical member is inserted, A groove extending from a position opposing the opening of the cylindrical member to an opening end of the insertion hole is formed on an inner wall of the insertion hole. 4. The vacuum pump according to claim 2 or 3, characterized in that, The opening is formed closer to the valve seat than the center of the valve core in the axial direction of the cylindrical member so as to at least partially overlap the valve core at the restricting position of the stopper. side. 5. The vacuum pump according to claim 2 or 3, characterized in that, The spool has a spherical shape, The opening has a shape through which the spool cannot pass.

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