Vacuum pump valve device

Abstract

To improve the durability of the valve body in the valve mechanism of a vacuum pump. [Solution] The valve device of the vacuum pump of the present invention comprises an annular valve seat disposed within a cylindrical housing that constitutes a fluid passage, a valve body 80 having an annular projection 83 facing the valve seat, and a spring that presses the annular projection 83 of the valve body 80 against the valve seat. The valve body 80 has a recess 84 surrounded by the annular projection 83, and a reinforcing rib 85 connected to the annular projection 83 is disposed within the recess 84, thereby improving the durability of the valve body 80.

Description

Technical Field

[0001] The present invention relates to a valve device for a vacuum pump.

Background Art

[0002] Conventionally, a vehicle is provided with a master booster that assists the driver's stepping force when stepping on the brake pedal. The master booster is defined by a negative pressure chamber and an atmospheric chamber, and by utilizing the differential pressure between the negative pressure chamber and the atmospheric chamber, the stepping force of the brake pedal is multiplied and transmitted to the master cylinder. Such a master booster is connected to a vacuum pump via a pipe, and negative pressure can be generated by operating the vacuum pump. The vacuum pump has a valve device on the pipe side connected to the master booster, and the valve device can hold the master booster side at negative pressure.

[0003] Patent Document 1 discloses a pressure control valve used for a double-acting vacuum pump. In the pressure control valve disclosed in Patent Document 1, a valve body and a spring are arranged in a fluid passage of a control valve housing. The valve body has an annular protrusion facing a valve seat formed by a step on the inner peripheral surface of the fluid passage. When the valve body is pressed by the biasing force of the spring and the annular protrusion of the valve body is pressed against the valve seat, the fluid passage is closed. On the other hand, when negative pressure of the fluid acts on the valve body, the annular protrusion separates from the valve seat against the biasing force of the spring, and the fluid passage is opened.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the pressure control valve described in Patent Document 1, the annular projection of the valve body is repeatedly pressed against the valve seat, causing it to wear down and potentially tilt outwards. When the annular projection tilts outwards, the valve body can no longer move smoothly, which is a problem.

[0006] This invention has been made in view of the above-mentioned problems, and aims to improve the durability of the valve body. [Means for solving the problem]

[0007] The present invention relates to a valve device for a vacuum pump, comprising an annular valve seat disposed within a cylindrical housing constituting a fluid passage, a valve body having an annular projection facing the valve seat, and a spring that presses the annular projection of the valve body against the valve seat, wherein the valve body has a recess surrounded by the annular projection, and a reinforcing rib connected to the annular projection is disposed within the recess. [Effects of the Invention]

[0008] According to the present invention, the durability of the valve body can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram shows a schematic configuration of a vehicle equipped with a vacuum pump valve mechanism. [Figure 2] This is a cross-sectional view showing an example of the configuration of a valve device. [Figure 3] This is a perspective view showing an example of the valve body's structure. [Figure 4] These are a plan view and a cross-sectional view showing an example of the valve body configuration. [Modes for carrying out the invention]

[0010] The valve device 40 of the vacuum pump 20 according to the present invention includes an annular valve seat 53 disposed within a cylindrical housing 50 that constitutes a fluid passage 51, a valve body 80 having an annular projection 83 facing the valve seat 53, and a spring 60 that presses the annular projection 83 of the valve body 80 against the valve seat 53. The valve body 80 has a recess 84 surrounded by the annular projection 83, and a reinforcing rib 85 connected to the annular projection 83 is disposed within the recess 84. Therefore, the durability of the valve body 80 can be improved. [Examples]

[0011] The valve device of the vacuum pump according to the present invention will be described below with reference to the drawings. Figure 1 shows a schematic configuration of a vehicle 1 equipped with a valve device 40 of a vacuum pump 20. Note that Figure 1 is a simplified representation for the purpose of explaining this embodiment, and components that a vehicle would normally have are assumed to be present even if they are not shown in the figure.

[0012] Vehicle 1 in this embodiment is equipped with an engine 10 as an internal combustion engine, a vacuum pump 20, a master cylinder 30, and the like. The engine 10 generates driving force by performing a series of strokes consisting of an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke. The driving force generated by the engine 10 is transmitted to the wheels via the crankshaft 11, causing the vehicle 1 to move.

[0013] The vacuum pump 20 is a pump that generates negative pressure inside the master cylinder 30 by sucking air from inside the master cylinder 30 through the vacuum hose 31. The vacuum pump 20 has a vane as a rotating body inside, and negative pressure is generated by the rotation of the vane. The vacuum pump 20 is also located adjacent to the engine 10 and operates in conjunction with the operation of the engine 10. Specifically, the vacuum pump 20 operates in conjunction with the rotation of the camshaft 12, which is connected to the crankshaft 11 of the engine 10 via a cam chain. Therefore, the vacuum pump 20 operates when the engine 10 is running and stops operating when the engine 10 is not running.

[0014] Furthermore, the vacuum pump 20 is equipped with a valve device 40. The valve device 40 is a so-called check valve, to which one end of the vacuum hose 31 is connected. The valve device 40 opens when the vacuum pump 20 is operating and closes when the vacuum pump 20 is stopped. Therefore, when the vacuum pump 20 is operating, air drawn in from inside the master back 30 flows to the vacuum pump 20 through the open valve device 40, creating negative pressure inside the master back 30. On the other hand, when the vacuum pump 20 is stopped, the valve device 40 is closed, preventing air from flowing to the master back 30, thus maintaining a negative pressure state inside the master back 30. The specific configuration of the valve device 40 will be described later with reference to Figures 2 to 4.

[0015] The master booster 30 assists the depressing force from the brake pedal 32 due to the internal pressure difference. The master booster 30 includes a housing 33, and the interior of the housing 33 is partitioned by a diaphragm into a negative pressure chamber and an atmospheric chamber. The other end of the vacuum hose 31 is connected to the housing 33. Therefore, the interior of the housing 33 is maintained at a negative pressure by the vacuum pump 20. The atmospheric chamber is introduced with air from the negative pressure state in response to the depression of the brake pedal 32. Therefore, when the brake pedal 32 is depressed, the depressing force is amplified by the introduction of air and output to the master cylinder 34. The master cylinder 34 generates a brake hydraulic pressure corresponding to the depressing force amplified by the master booster 30, and the vehicle 1 is braked by the brake operating unit restricting the rotation of the wheels using the brake hydraulic pressure.

[0016] Next, the configuration of the valve device 40 of the vacuum pump 20 will be described. FIG. 2 is a cross-sectional view showing an example of the configuration of the valve device 40. In each of the figures after FIG. 2, for ease of understanding, the longitudinal direction of the housing 50 described later is shown as the vertical direction, with one side being the upper side and the other side being the lower side. The valve device 40 has a housing 50, a spring 60, a support member 70, and a valve body 80.

[0017] The housing 50 is formed in a cylindrical shape and has a fluid passage 51 through which fluid flows inside and a valve seat 53 with which the valve body 80 contacts. The fluid passage 51 is composed of a first passage 52a and a second passage 52b.

[0018] The first passage 52a is a passage along the vertical direction and is located above the housing 50. The first passage 52a communicates with a connecting pipe 35 coupled to the housing 50 for connecting the vacuum hose 31. The second passage 52b is a passage along the vertical direction that communicates with the first passage 52a and is located below the housing 50. The second passage 52b is formed with an inner diameter larger than that of the first passage 52a. Also, the second passage 52b communicates with the interior of the vacuum pump 20.

[0019] The valve seat 53 is formed by a step resulting from the difference between the inner diameter of the first passage 52a and the inner diameter of the second passage 52b. The valve seat 53 is formed by a part of the wall surface of the second passage 52a and is located near the boundary between the first passage 52a and the second passage 52b. Specifically, the valve seat 53 is a surface formed in an annular shape that appears when the housing 50 is viewed from below.

[0020] The spring 60 is disposed between the support member 70 and the valve body 80, and presses the valve body 80 toward the valve seat 53 by an elastic force. The spring 60 is formed in a conical shape with the outer diameter of the upper side being smaller than the outer diameter of the lower side.

[0021] The support member 70 is a member that supports the lower end (one end side) of the spring 60. The support member 70 is disposed at the lower end of the second passage 52b. The support member 70 is formed with a substantially constant plate thickness and has a bulging portion 71 whose center bulges substantially hemispherically upward and an outer peripheral portion 72 located at the outer peripheral edge of the bulging portion 71. By fitting the spring 60 into the bulging portion 71 so that the lower end of the spring 60 surrounds the bulging portion 71, the lower end of the spring 60 can be positioned. A plurality of through holes 73 penetrating in the vertical direction are formed in the bulging portion 71 and the outer peripheral portion 72, and fluid can flow through the through holes 73.

[0022] The valve body 80 is located in the second passage 52b of the housing 50, and is a member for opening the fluid passage 51 so that fluid can flow through the fluid passage 51 or closing the fluid passage 51 so that fluid cannot flow through the fluid passage 51. The valve body 80 is made of, for example, rubber or soft synthetic resin. Further, the valve body 80 has a shape in which two cylinders are connected in a stacked manner, and has a support portion 81 and a valve portion 82.

[0023] The support portion 81 is located below the valve portion 82 and is approximately cylindrical or disc-shaped with a smaller outer diameter than the valve portion 82. The support portion 81 is the part that supports the upper end (other end) of the spring 60. The upper end of the spring 60 can be positioned by fitting the spring 60 into the support portion 81 such that the upper end of the spring 60 surrounds the support portion 81. The valve portion 82 is located above the support portion 81 and is approximately cylindrical or disc-shaped with a larger outer diameter than the support portion 81. The outer diameter of the valve portion 82 is larger than the inner diameter of the first passage 52a of the fluid passage 51 and smaller than the inner diameter of the second passage 52b.

[0024] Figure 3 is a perspective view showing an example of the configuration of the valve body 80. Figure 4(a) is a plan view of the valve body 80 seen from above, and Figure 4(b) is a cross-sectional view taken along line II and seen from the direction of the arrow. The valve portion 82 of the valve body 80 has an annular projection 83 and a recess 84.

[0025] The annular projection 83 is located on the upper part and outer edge of the valve portion 82 and is a part that protrudes upward. The annular projection 83 is a continuous annular shape when viewed from above. When the valve body 80 is positioned in the second passage 52b, the annular projection 83 faces the valve seat 53, and the annular projection 83 comes into contact with the valve seat 53 as the valve body 80 is pressed against it by the spring 60. Also, as shown in Figure 4(b), the width W1 of the annular projection 83 gradually decreases towards the upper end (tip).

[0026] The recess 84 is located at the top and center of the valve portion 82 and is a recessed area that slopes downward. The recess 84 is formed by being surrounded by the annular projection 83 and is a circular space when viewed from above. When the valve body 80 is positioned in the second passage 52b, even if the valve body 80 is pressed against it by the spring 60, the annular projection 83 contacts the valve seat 53, so the recess 84 does not contact the valve seat 53.

[0027] In this embodiment, the valve portion 82 has a reinforcing rib 85 connected to the annular projection 83 located within the recess 84 to prevent the annular projection 83 from collapsing due to wear. The reinforcing rib 85 protrudes upward from the bottom surface of the recess 84. In this embodiment, the reinforcing rib 85 is formed in a cross shape when viewed from above by rib 86a and rib 86b. Specifically, rib 86a and rib 86b are arranged in a straight line so as to connect the inner circumference of the annular projection 83 to each other. Also, when viewed from above, rib 86a and rib 86b are arranged radially from the center O of the valve portion 82 toward the annular projection 83. By arranging the reinforcing rib 85 connected to the annular projection 83 in this way, the strength of the annular projection 83 can be improved, thereby preventing the annular projection 83 from collapsing due to sagging.

[0028] Furthermore, as shown in Figure 4(b), the height H2 of ribs 86a and ribs 86b from the bottom surface of the recess 84 to the upper end (tip) is lower than the height H1 of the annular projection 83 from the bottom surface of the recess 84 to the upper end (tip). In this way, because the height H2 of ribs 86a and ribs 86b is lower than the height H1 of the annular projection 83, the tip of the annular projection 83 deforms so as to be crushed when it comes into contact with the valve seat 53, thereby improving the sealing performance between the annular projection 83 and the valve seat 53. Also, as shown in Figure 4(b), the width W2 of ribs 86a and ribs 86b gradually decreases towards the upper end (tip), thereby improving the strength of ribs 86a and ribs 86b themselves.

[0029] As described above, the vacuum pump 20 starts operating in conjunction with the engine 10 when it is driven. When the vacuum pump 20 starts operating, the valve device 40 opens, drawing air from inside the master back 30 housing 33 through the vacuum hose 31. Specifically, the valve body 80 of the valve device 40 moves downward (towards the support member 70) against the elastic force of the spring 60 due to the negative pressure from the vacuum pump 20. Therefore, the valve opens when the annular projection 83 of the valve body 80 moves from a state of contact with the valve seat 53 to a state of separation from the valve seat 53, causing air inside the master back 30 housing 33 to flow from the first passage 52a to the second passage 52b of the fluid passage 51, thereby creating negative pressure inside the master back 30 housing 33.

[0030] On the other hand, the vacuum pump 20 stops operating when the engine 10 is not driven. When the vacuum pump 20 stops operating, air is not sucked into the housing 33 of the master back 30, but the valve device 40 closes, maintaining negative pressure inside the housing 33 of the master back 30. Specifically, the valve body 80 of the valve device 40 moves upward (towards the first passage 52a) due to the elastic force of the spring 60 when the negative pressure effect from the vacuum pump 20 is removed. Therefore, the valve closes when the annular projection 83 of the valve body 80 moves from a state away from the valve seat 53 to a state in contact with the valve seat 53, preventing air from flowing from the second passage 52b of the fluid passage 51 to the first passage 52a from the vacuum pump 20 side to the master back 30 side, thus maintaining negative pressure inside the housing 33 of the master back 30.

[0031] Even if the valve body 80 repeatedly opens and closes due to the operation of the vacuum pump 20, causing the annular projection 83 to be repeatedly pressed against the valve seat 53 and then separated from the valve seat 53, the annular projection 83 can be prevented from collapsing due to sagging by the reinforcing rib 85, thereby preventing malfunction of the valve device 40.

[0032] As described above, the valve device 40 of the vacuum pump 20 in this embodiment has a recess 84 in which the valve body 80 is surrounded by annular projections 83, and reinforcing ribs 85 connected to the annular projections 83 are arranged within the recess 84. Therefore, the reinforcing ribs 85 can prevent the annular projections 83 from collapsing due to wear, thereby improving the durability of the valve body 80.

[0033] Furthermore, in this embodiment, the reinforcing rib 85 is formed such that the height H2 from the bottom surface of the recess 84 to the tip is lower than the height H1 from the bottom surface of the recess 84 to the tip of the annular projection 83. Therefore, when the annular projection 83 comes into contact with the valve seat 53, the tip of the annular projection 83 deforms so as to be crushed, thereby improving the sealing performance between the annular projection 83 and the valve seat 53.

[0034] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and modifications can be made within the scope of the present invention.

[0035] In the above-described embodiment, the reinforcing rib 85 was described as being formed in a cross shape by ribs 86a and 86b when viewed from above, but it is not limited to this case. The reinforcing rib 85 only needs to be connected to the annular projection 83 so that the annular projection 83 does not deteriorate, and the shape of the reinforcing rib 85 is not limited. For example, the number of ribs in the reinforcing rib 85 may be one or two or more, and the ribs may be formed intermittently by leaving some of the ribs missing. [Explanation of Symbols]

[0036] 1: Vehicle 10: Engine 20: Vacuum pump 30: Master cylinder 40: Valve mechanism 50: Housing 60: Spring 70: Support member 80: Valve body 82: Valve section 83: Annular projection 84: Recess 85: Reinforcement rib 86a, 86b: Rib

Claims

1. An annular valve seat is positioned within a cylindrical housing that constitutes a fluid passage, A valve body having an annular projection facing the valve seat, A valve device for a vacuum pump having a spring that presses the annular projection of the valve body against the valve seat, The valve body has a recess surrounded by the annular projection, A valve device for a vacuum pump, characterized in that a reinforcing rib connected to the annular projection is arranged within the recess.

2. The valve device for a vacuum pump according to claim 1, characterized in that the height of the reinforcing rib from the bottom surface of the recess to the tip is lower than the height of the annular projection from the bottom surface of the recess to the tip.

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