JP2009236242A - Relief valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the vibration of a ball bed, and to suppress the drop of relief pressure in course of usage, in a relief valve. <P>SOLUTION: In the relieve valve 20, a ball bed holder 40 has: a base plate 41, which contacts the end surface of a small diameter part 24a of the ball bed 24; and a vibration-proof seal 42 bonded to the outer peripheral part of the base plate 41. The vibration-proof seal 42 is made of rubber structured with a clamping part 43, one end of which is bonded to the base plate 41 and which clamps the outside circumference of the small part 24a of the ball bed 24, and a lip part 44, which is extended outward along the radial direction from one end side bonded to the base plate 41 of the clamping part 43 and to the side of a ball 23 along the axial direction and which slidably contacts the inside surface of a valve hole 21a. Rubber hardness of the vibration seal 42 is set within the range of Hs75-Hs65. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a relief valve suitable for use in a hydraulic control system such as a power steering device for a vehicle.

  As a conventional relief valve, a valve housing with a valve hole drilled along the axial direction, and a hydraulic pump from one end of a communication hole that is fitted and fixed to the opening end of the valve hole and penetrates along the axial direction. The discharged pressure oil is introduced, and a valve seat member having a valve seat formed at the other end, a ball that contacts the valve seat and closes the communication hole, holds the ball, and the valve hole And a relief spring that urges the ball receiver in a direction in which the ball comes into contact with the valve seat, and relieves the pressure oil when the pressure oil is relieved. Some relief holes open in the radial direction of the valve hole. In this relief valve, during the relief, the ball receiver causes self-excited vibration due to the total discharge flow rate of the pump flowing out of the relief valve, and a beep sound is generated.

  However, as a relief valve for preventing the vibration of the ball receiver, there is a relief valve in which a vibration isolating ring comprising a rubber O-ring and a PTFE ring is interposed between the ball receiver and the relief spring as described in Patent Document 1. . This is because the vibration-proof ring is pressed against the ball receiver by the relief spring, and the rubber O-ring of the vibration-proof ring is expanded to bring the vibration-proof ring into contact with the inner surface of the valve hole, thereby vibrating the ball receiver. It is to suppress.

  However, in the relief valve described in Patent Document 1, the rubber O-ring of the vibration isolating ring is compressed in the axial direction between the ball receiver and the ball receiver by the relief spring to be expanded in the radial direction. The expanded O-ring causes a phenomenon of sticking to the inner surface of the valve hole due to the hardening of the rubber when the oil is at a low temperature, and there is a possibility that the relief does not occur even if the hydraulic pressure exceeds the set pressure. In addition, when the set pressure changes due to deterioration over a long period of time, the relief valve does not operate normally, and a phenomenon occurs in which oil leakage occurs in each part of the cylinder and pump.

Accordingly, there is a relief valve shown in FIG. 5 as a relief valve that suppresses vibration of the ball receiver and stabilizes the relief pressure. In FIG. 5, 101 is a valve housing, 102 is a valve seat member, 103 is a ball, 104 is a ball receiver, 105 is a relief spring, and 106 is a ball receiver holder. The ball receiving holder 106 is backed up by a relief spring 105 and is made of a metal substrate 107 that contacts the end surface of the small diameter portion 104a of the ball receiver 104, and a rubber vibration-proof seal 108 that is bonded to the outer edge of the substrate 107. Consists of. The anti-vibration seal 108 includes a hugging portion 108 a that is hugged on the outer periphery of the small diameter portion 104 a of the ball receiver 104, and a lip that extends from the hugging portion 108 a and slidably contacts the inner surface of the valve hole 101 a of the valve housing 101. Part 108b. The outer diameter of the lip portion 108b of the anti-vibration seal 108 is slightly larger than the inner diameter of the valve hole 101a, and the lip portion 108b of the anti-vibration seal 108 is elastically slightly reduced in diameter so that the valve By lightly slidingly contacting the inner surface of the hole 101a, it is intended to avoid sticking or deterioration of the vibration-proof seal 108 to the inner surface of the valve hole 101a.
Patent 2878552

  In the relief valve of FIG. 5, the hydraulic pressure discharged from the hydraulic pump and acting on the ball 103 exceeds the spring force of the relief spring 105 and the frictional resistance force exerted on the inner surface of the valve hole 101a by the lip portion 108b of the vibration-proof seal 108. Sometimes, the ball 103 is opened to relieve the discharge hydraulic pressure of the hydraulic pump. Therefore, if the lip portion 108b of the vibration-proof seal 108 fits into the inner surface of the valve hole 101a with the progress of use and the frictional resistance decreases, the discharge hydraulic pressure of the hydraulic pump is relieved even at a low pressure, leading to a decrease in the relief pressure.

  In the prior art, the friction resistance force exerted on the inner surface of the valve hole 101a by the lip portion 108b of the anti-vibration seal 108 at the initial stage of use of the relief valve is set to a high value. There is an inconvenience that the pressure increases and the amount of decrease in the relief pressure increases.

  An object of the present invention is to suppress vibration of a ball receiver in a relief valve and to suppress a decrease in relief pressure due to the course of use.

  According to a first aspect of the present invention, there is provided a valve housing having a valve hole formed along an axial direction, and a hydraulic pump provided at one end of a communication hole provided at an opening end of the valve hole and penetrating along the axial direction. The discharged pressure oil is introduced, a valve seat portion having a valve seat formed at the other end portion, a ball that contacts the valve seat and closes the communication hole, and holds the ball, the valve hole A ball receiver that is slidable along the inner surface of the ball, a relief spring that urges the ball receiver in a direction in which the ball contacts the valve seat, and an outer periphery of a small-diameter portion of the ball receiver. And a ball receiving holder provided with a vibration-proof seal that is slidable along the inner surface of the valve hole, and a relief hole that relieves the pressure oil when the hydraulic pressure is relieved opens in a radial direction of the valve hole. In the relief valve, the ball receiver The holder has a substrate that contacts the end surface of the small-diameter portion of the ball receiver, and an anti-vibration seal that is bonded to the outer edge of the substrate, and the anti-vibration seal is bonded to the substrate at one end to A hugging portion to be hugged on the outer periphery, and extends from the one end side bonded to the substrate of the hugging portion to the outer side along the radial direction and the ball side along the axial direction, and slidably contacts the inner surface of the valve hole. The anti-vibration seal has a rubber hardness within a range of Hs75 to Hs65.

  According to a second aspect of the present invention, there is provided a valve housing having a valve hole formed along an axial direction, and a hydraulic pump provided at one end of a communication hole provided at an opening end of the valve hole and penetrating along the axial direction. The discharged pressure oil is introduced, a valve seat portion having a valve seat formed at the other end portion, a ball that contacts the valve seat and closes the communication hole, and holds the ball, the valve hole A ball receiver that is slidable along the inner surface of the ball, a relief spring that urges the ball receiver in a direction in which the ball contacts the valve seat, and an outer periphery of a small-diameter portion of the ball receiver. And a ball receiving holder provided with a vibration-proof seal that is slidable along the inner surface of the valve hole, and a relief hole that relieves the pressure oil when the hydraulic pressure is relieved opens in a radial direction of the valve hole. In the relief valve, the ball receiver The holder has a substrate that contacts the end surface of the small-diameter portion of the ball receiver, and an anti-vibration seal that is bonded to the outer edge of the substrate, and the anti-vibration seal is bonded to the substrate at one end to A hugging portion to be hugged on the outer periphery, and extends from the one end side bonded to the substrate of the hugging portion to the outer side along the radial direction and the ball side along the axial direction, and slidably contacts the inner surface of the valve hole. The maximum outer diameter portion of the anti-vibration seal lip portion in the free state is formed with respect to the end surface of the substrate that is not in contact with the end surface of the small-diameter portion of the ball receiver. The distance is set to 1.5 mm or more.

  According to a third aspect of the present invention, there is provided a valve housing having a valve hole formed along an axial direction, and a hydraulic pump provided at one end of a communication hole provided at an opening end of the valve hole and penetrating along the axial direction. The discharged pressure oil is introduced, a valve seat portion having a valve seat formed at the other end portion, a ball that contacts the valve seat and closes the communication hole, and holds the ball, the valve hole A ball receiver that is slidable along the inner surface of the ball, a relief spring that urges the ball receiver in a direction in which the ball contacts the valve seat, and an outer periphery of a small-diameter portion of the ball receiver. And a ball receiving holder provided with a vibration-proof seal that is slidable along the inner surface of the valve hole, and a relief hole that relieves the pressure oil when the hydraulic pressure is relieved opens in a radial direction of the valve hole. In the relief valve, the ball receiver The holder has a substrate that contacts the end surface of the small-diameter portion of the ball receiver, and an anti-vibration seal that is bonded to the outer edge of the substrate, and the anti-vibration seal is bonded to the substrate at one end to A hugging portion to be hugged on the outer periphery, and extends from the one end side bonded to the substrate of the hugging portion to the outer side along the radial direction and the ball side along the axial direction, and slidably contacts the inner surface of the valve hole. The angle formed by the extending direction of the lip portion of the anti-vibration seal with respect to the direction along the end surface of the substrate is set within a range of 60 degrees to 50 degrees. It is a thing.

  According to a fourth aspect of the present invention, there is provided a valve housing having a valve hole formed along the axial direction, and a hydraulic pump provided at one end of the communication hole provided at the opening end of the valve hole and penetrating along the axial direction. The discharged pressure oil is introduced, a valve seat portion having a valve seat formed at the other end portion, a ball that contacts the valve seat and closes the communication hole, and holds the ball, the valve hole A ball receiver that is slidable along the inner surface of the ball, a relief spring that urges the ball receiver in a direction in which the ball contacts the valve seat, and an outer periphery of a small-diameter portion of the ball receiver. And a ball receiving holder provided with a vibration-proof seal that is slidable along the inner surface of the valve hole, and a relief hole that relieves the pressure oil when the hydraulic pressure is relieved opens in a radial direction of the valve hole. In the relief valve, the ball receiver The holder has a substrate that contacts the end surface of the small-diameter portion of the ball receiver, and an anti-vibration seal that is bonded to the outer edge of the substrate, and the anti-vibration seal is bonded to the substrate at one end to A hugging portion to be hugged on the outer periphery, and extends from the one end side bonded to the substrate of the hugging portion to the outer side along the radial direction and the ball side along the axial direction, and slidably contacts the inner surface of the valve hole. The round radius of the crossing surface portion where the lip portion of the vibration-proof seal intersects the hugging portion is made to be R0.1 mm or less.

  According to a fifth aspect of the present invention, there is provided a valve housing having a valve hole formed along an axial direction, and a hydraulic pump provided at one end of a communication hole provided at an opening end of the valve hole and penetrating along the axial direction. The discharged pressure oil is introduced, a valve seat portion having a valve seat formed at the other end portion, a ball that contacts the valve seat and closes the communication hole, and holds the ball, the valve hole A ball receiver that is slidable along the inner surface of the ball, a relief spring that urges the ball receiver in a direction in which the ball contacts the valve seat, and an outer periphery of a small-diameter portion of the ball receiver. And a ball receiving holder provided with a vibration-proof seal that is slidable along the inner surface of the valve hole, and a relief hole that relieves the pressure oil when the hydraulic pressure is relieved opens in a radial direction of the valve hole. In the relief valve, the ball receiver The holder has a substrate that contacts the end surface of the small-diameter portion of the ball receiver, and an anti-vibration seal that is bonded to the outer edge of the substrate, and the anti-vibration seal is bonded to the substrate at one end to A hugging portion to be hugged on the outer periphery, and extends from the one end side bonded to the substrate of the hugging portion to the outer side along the radial direction and the ball side along the axial direction, and slidably contacts the inner surface of the valve hole. The angle formed by the extending direction of the anti-vibration seal lip with respect to the direction along the end face of the substrate is set within a range of 60 ° to 50 °, and the anti-vibration seal is formed. The round radius of the intersecting surface portion where the lip portion of the vibration seal intersects the hugging portion is set to R0.1 mm or less.

(Claim 1)
(a) The rubber hardness of the vibration-proof seal was determined within the range of Hs75 to Hs65. Accordingly, the rubber hardness of the vibration-proof seal is made softer than that of the conventional Hs80, and the friction resistance force exerted on the inner surface of the valve hole by the lip portion of the vibration-proof seal is low at the initial use stage of the relief valve. . As a result, the amount of decrease in the frictional resistance after the lip portion of the vibration-proof seal has become familiar with the inner surface of the valve hole as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

(Claim 2)
(b) The distance that the maximum outer diameter portion in the free state of the lip portion of the anti-vibration seal forms with respect to the end surface of the substrate not contacting the end surface of the small-diameter portion of the ball receiver is 1.5 mm or more. Therefore, the distance that the point where the maximum outer diameter of the lip portion of the vibration-proof seal is pressed against the inner surface of the valve hole is longer than the conventional 1.1 mm, and the lip portion with the substrate as a fulcrum is longer. Friction resistance force that reduces the bending reaction force (the lip part is easily bent to the reduced diameter side relative to the hugging part), and the anti-vibration seal lip part exerts on the inner surface of the valve hole in the initial stage of use of the relief valve Will be low. As a result, the amount of decrease in the frictional resistance after the lip portion of the vibration-proof seal has become familiar with the inner surface of the valve hole as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

(Claim 3)
(c) The angle formed by the extending direction of the lip portion of the vibration-proof seal with respect to the direction along the end face of the substrate was determined within a range of 60 degrees to 50 degrees. Therefore, the angle formed by the extending direction of the lip portion of the vibration-proof seal with respect to the direction along the end face of the substrate is made larger than the conventional 45 degrees, and the angle formed by the extending direction of the lip portion with respect to the inner surface of the valve hole is set. A small angle makes it easy to reduce the diameter of the maximum outer diameter portion of the lip portion with a small force generated between the inner surface of the valve hole (the lip portion is easily bent toward the reduced diameter side with respect to the hugging portion) The frictional resistance force exerted on the inner surface of the valve hole by the lip portion of the vibration-proof seal is low at the initial use stage of the relief valve. As a result, the amount of decrease in the frictional resistance after the lip portion of the vibration-proof seal has become familiar with the inner surface of the valve hole as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

(Claim 4)
(d) The roundness radius of the intersecting surface portion where the lip portion of the vibration-proof seal intersects the hugging portion is set to R 0.1 mm or less. Therefore, the rounded radius of the crossing surface portion where the lip portion of the vibration-proof seal intersects the hugging portion is made smaller than the conventional R0.2 mm, and the lip portion is easily bent to the reduced diameter side with respect to the hugging portion. In the initial stage of use of the relief valve, the frictional resistance force exerted on the inner surface of the valve hole by the lip portion of the vibration-proof seal is low. As a result, the amount of decrease in the frictional resistance after the lip portion of the vibration-proof seal has become familiar with the inner surface of the valve hole as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

(Claim 5)
(e) The angle formed by the extending direction of the lip portion of the vibration-proof seal with respect to the direction along the end face of the substrate is set within a range of 60 ° to 50 °, and the lip portion of the vibration-proof seal intersects the holding portion. The round radius of the intersecting surface portion is set to R0.1 mm or less. Therefore, the above (c) and (d) can be achieved simultaneously.

(Claims 1-5)
(f) The anti-vibration seal attached to the ball holder has a lip portion whose outer diameter in the free state is slightly larger than the inner diameter of the valve hole, and the lip portion is slightly reduced in diameter by its own elastic deformation, so that the valve hole Lightly slidably contact the inner surface. Thereby, the vibration of the ball receiver can be suppressed without causing the vibration-proof seal to be compressed and pressed against the inner surface of the valve hole and causing sticking or deterioration.

  1 is a sectional view showing a pump, FIG. 2 is a sectional view showing a relief valve of an example of the present invention, FIG. 3 shows the position of the maximum outer diameter portion of the lip portion of the vibration-proof seal, and FIG. 4B is a cross-sectional view showing a conventional example, FIG. 4 is a cross-sectional view showing an example of the present invention, and FIG. 4D is a cross-sectional view showing an example of the present invention. FIG. 5 is a sectional view showing a conventional relief valve.

  The variable displacement pump shown in FIG. 1 is an example of a vane type variable displacement pump that serves as a hydraulic pressure generation source for a vehicle power steering apparatus. A relief valve 20 is provided in a switching valve 17 that controls the pressure in a first fluid chamber. Built in.

  In this figure, a rotor 2 attached to a pump rotary shaft 1 rotates in an eccentric cam ring 3 to form a pump chamber 9 between the cam ring 3 and the cam ring 3 via an outer case 4. And supported by the pump housing 5. 6 is a pump housing cap, 7 is a preload spring.

  A plurality of vanes 8 are attached to the outer periphery of the rotor 2 in the circumferential direction, and the tips thereof are in contact with the inner peripheral surface of the cam ring 3. Therefore, when the rotor 2 rotates, the hydraulic oil sucked from the suction port 10 is discharged from the discharge port 11 through the pump chamber 9. The hydraulic oil discharged from the discharge port 11 passes through the variable orifice 12, passes through the discharge passage 30, and is sent to an external device.

  Reference numeral 15 denotes a valve storage hole which is provided in a part of the pump housing 5 and whose one end (the left end in the figure) is closed by a plug 16. In the valve storage hole 15, the valve body 21 of the switching valve 17 is provided. It is housed and biased toward the plug 16 by the switching valve spring 18. The fluid pressure on the upstream side of the variable orifice 12 provided in the pump discharge side passage is applied to the first valve chamber 19 a formed on the left side of the switching valve body 21 through the passage 28, A fluid pressure downstream of the variable orifice 12 is applied to the second valve chamber 19b formed on the right side.

  When the pump rotates at a high speed, the pressure in the first valve chamber 19a on the left side of the switching valve valve body 21 increases, so that the switching valve valve body 21 moves to the right in the figure against the force of the switching valve spring 18. . Then, the passage 29 opens to the first valve chamber 19a, and the hydraulic oil in the first valve chamber 19a passes through the passage 29 and is introduced into the first fluid chamber 13a between the cam ring 3 and the outer case 4. . On the other hand, the pressure on the downstream side of the variable orifice 12 is introduced into the second fluid chamber 13b. Thus, during high-speed rotation, the pressure before and after the variable orifice 12 is introduced into the first fluid chamber 13a and the second fluid chamber 13b, respectively, so that the cam ring 3 shifts due to the differential pressure, and the suction port 10 The area decreases, and the pump discharge rate decreases.

  FIG. 2 is an enlarged cross-sectional view showing the valve body 21 of the switching valve 17 taken out. The switching valve 17 incorporates a relief valve 20, and the switching valve body 21 is also a housing of the relief valve 20. The relief valve housing 21 is provided with a valve hole 21a along the axial direction. A valve seat member 22 is fitted into the opening end of the valve hole 21a, and is fixed by caulking at a position indicated by reference numeral 22a. The valve seat member 22 is provided with a communication hole 22b penetrating in the axial direction, and one end portion (the right end in the figure) of the communication hole 22b opens into the second valve chamber 19b of FIG. Pressure on the downstream side of the orifice 12 is introduced, and a valve seat 22c is formed at the other end (left end in the figure).

  A ball 23 abuts the valve seat 22c and closes the communication hole 22b. A ball receiver 24 holds the ball 23 and is slidably supported along the inner surface of the valve hole 21a. The ball receiver 24 is urged by a relief spring 25 in the direction in which the ball 23 comes into contact with the valve seat 22c (right side in the figure).

  In this embodiment, a ball receiving holder 40 is interposed between the ball receiver 24 and the relief spring 25 on the opposite side of the ball receiver 24 from the ball 23. The ball receiving holder 40 includes a metal substrate 41 that contacts the end surface of the small-diameter portion 24a near the anti-ball 23 of the ball receiver 24, and an outer edge portion of the substrate 41 (an outer peripheral range having a larger diameter than the small-diameter portion 24a of the ball receiver 24). And an anti-vibration seal 42 made of rubber that is baked and bonded.

  An anti-vibration seal 42 is an annular attachment that has one end bonded to the abutting inner end surface of the substrate 41 that contacts the small diameter portion 24 a of the ball receiver 24, and is press-fitted into the outer periphery of the small diameter portion 24 a of the ball receiver 24. Part 43 and the entire circumference of one end side bonded to the substrate 41 of the hugging part 43 extend outward in the radial direction and opposite to the ball 23 side in the axial direction, and slide on the inner surface of the valve hole 21a. It is made of rubber having a lip portion 44 in contact therewith. The lip portion 44 extends the base end portion on the hugging portion 43 side to the outer periphery of the substrate 41. The hugging portion 43 and the lip portion 44 form a V-shaped cross section that opens toward the ball 23 in a longitudinal sectional view along the axial direction of the vibration-proof seal 42, and the bottom of the V-shape is the outer edge portion of the substrate 41. It is baked and bonded. The vibration-proof seal 42 is set in the valve hole 21a in a state where the maximum outer diameter portion of the tip portion 44a of the lip portion 44 is set to be larger than the inner diameter of the valve hole 21a in a free state. . Thereby, the front-end | tip part 44a of the lip | rip part 44 of the vibration-proof seal 42 is made slidable along the inner surface of the valve hole 21a.

  The relief valve housing 21 in the vicinity of the valve seat 22c is provided with a relief hole 21b in the radial direction, and communicates with an annular notch 21c provided on the outer peripheral surface of the valve housing 21 over the entire circumference. Yes. The annular notch 21c communicates with the drain passage 31 shown in FIG. 1 or the suction port of the hydraulic pump.

  However, the relief valve 20 includes at least one of the following configurations in order to suppress the vibration of the ball receiver 24 and to suppress a decrease in the relief pressure due to the course of use. The relief valve 20 can also include one or more of the following configurations.

  (A) The anti-vibration seal 42 of the ball receiving holder 40 determines its rubber hardness within the range of Hs75 to Hs65, more preferably Hs70.

According to the present embodiment, the following operational effects can be obtained.
(a) The rubber hardness of the anti-vibration seal 42 is set within the range of Hs75 to Hs65. Accordingly, the rubber hardness of the vibration-proof seal 42 is made softer than that of the conventional Hs80, and the frictional resistance force that the lip portion 44 of the vibration-proof seal 42 exerts on the inner surface of the valve hole 21a at the initial use stage of the relief valve 20. Will be low. As a result, the amount of decrease in the frictional resistance force after the lip portion 44 of the vibration-proof seal 42 becomes familiar with the inner surface of the valve hole 21a as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

  (B) The maximum outer diameter portion P1 in the free state of the lip portion 44 of the anti-vibration seal 42 of the ball receiver holder 40 with respect to the outer end surface on the side where the substrate 41 does not contact the end surface of the small diameter portion 24a of the ball receiver 24. The formed distance L is set to 1.5 mm or more (FIG. 3A).

According to the present embodiment, the following operational effects can be obtained.
(b) The distance formed by the maximum outer diameter portion in the free state of the lip portion 44 of the anti-vibration seal 42 with respect to the end surface of the substrate 41 on the side not contacting the end surface of the small diameter portion 24a of the ball receiver 24 is 1.5 mm or more. did. Accordingly, the distance formed by the point where the maximum outer diameter portion of the lip portion 44 of the vibration-proof seal 42 is pressed against the inner surface of the valve hole 21a with respect to the substrate 41 is compared with the conventional 1.1 mm (FIG. 3B). The bending reaction force of the lip portion 44 with the substrate 41 as a fulcrum is reduced (the lip portion 44 is easily bent toward the diameter-reduced side with respect to the hugging portion 43), and is prevented at the initial use stage of the relief valve. The frictional resistance force exerted on the inner surface of the valve hole 21a by the lip portion 44 of the vibration seal 42 is low. As a result, the amount of decrease in the frictional resistance force after the lip portion 44 of the vibration-proof seal 42 becomes familiar with the inner surface of the valve hole 21a as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

  (C) The angle formed by the extending direction D of the lip portion 44 of the anti-vibration seal 42 of the ball receiving holder 40 with respect to the direction along the end surface of the substrate 41 is set within a range of 60 degrees to 50 degrees, and more preferably. It is set to 55 degrees (FIG. 4A).

According to the present embodiment, the following operational effects can be obtained.
(c) The angle formed by the extending direction of the lip portion 44 of the anti-vibration seal 42 with respect to the direction along the end surface of the substrate 41 is set within a range of 60 degrees to 50 degrees. Therefore, the angle formed by the extending direction of the lip portion 44 of the anti-vibration seal 42 with respect to the direction along the end surface of the substrate 41 is larger than the conventional 45 degrees (FIG. 4D), and the extending direction of the lip portion 44 is increased. Is made small with respect to the inner surface of the valve hole 21a, and the maximum outer diameter portion of the lip portion 44 is easily reduced in diameter with a small force generated between the inner surface of the valve hole 21a (the lip portion 44 is attached to the mounting portion). 43, and the friction resistance force exerted on the inner surface of the valve hole 21a by the lip portion 44 of the anti-vibration seal 42 becomes low at the initial use stage of the relief valve. As a result, the amount of decrease in the frictional resistance force after the lip portion 44 of the vibration-proof seal 42 becomes familiar with the inner surface of the valve hole 21a as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

  (D) Intersecting surface portion where the lip portion 44 of the anti-vibration seal 42 of the ball holder 40 intersects the hugging portion 43 (when the hugging portion 43 and the lip portion 44 intersect to form the aforementioned V-shaped cross section) The round radius of the V-shaped intersection formed by these surfaces is set to R 0.1 mm or less (FIG. 4B).

According to the present embodiment, the following operational effects can be obtained.
(d) The round radius of the intersecting surface portion where the lip portion 44 of the vibration-proof seal 42 intersects the hugging portion 43 is set to R 0.1 mm or less. Therefore, the round radius of the crossing surface portion where the lip portion 44 of the vibration-proof seal 42 intersects the hugging portion 43 is made smaller than the conventional R0.2 mm (FIG. 4D), and the lip portion 44 is changed to the hugging portion 43. On the other hand, it becomes easy to bend to the reduced diameter side, and the frictional resistance force exerted on the inner surface of the valve hole by the lip portion 44 of the vibration-proof seal 42 becomes low at the initial use stage of the relief valve. As a result, the amount of decrease in the frictional resistance force after the lip portion 44 of the vibration-proof seal 42 becomes familiar with the inner surface of the valve hole as a result of use is reduced, and as a result, the amount of decrease in the relief pressure can be reduced.

  (E) The angle formed by the extending direction D of the lip portion 44 of the anti-vibration seal 42 of the ball receiving holder 40 with respect to the direction along the end surface of the substrate 41 is determined within a range of 60 degrees to 50 degrees, and more preferably. An intersection surface portion where the lip portion 44 intersects the hugging portion 43 (when the hugging portion 43 and the lip portion 44 intersect to form the aforementioned V-shaped cross section, the surfaces thereof are formed. The round radius of the V-shaped intersection is set to R 0.1 mm or less (FIG. 4C).

According to the present embodiment, the following operational effects can be obtained.
(e) (c) of (C) and (d) of (D) are achieved simultaneously.

  In the relief valve 20, the anti-vibration seal 42 affixed to the ball receiver 24 makes the outer diameter of the lip portion 44 in a free state slightly larger than the inner diameter of the valve hole 21a, and the lip portion 44 is elastically deformed by itself. Thus, the diameter is slightly reduced to make light contact with the inner surface of the valve hole 21a. As a result, the vibration of the ball receiver 24 can be suppressed without causing the vibration-proof seal 42 to be compressed and pressed against the inner surface of the valve hole 21a and causing sticking or deterioration.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

FIG. 1 is a sectional view showing a pump. FIG. 2 is a cross-sectional view showing a relief valve of the present invention. 3A and 3B show the position of the maximum outer diameter portion of the lip portion of the vibration-proof seal. FIG. 3A is a cross-sectional view showing an example of the present invention, and FIG. FIG. 4 shows the shape of the lip portion of the vibration-proof seal, (A) to (C) are cross-sectional views showing examples of the present invention, and (D) is a cross-sectional view showing a conventional example. FIG. 5 is a cross-sectional view showing a conventional relief valve.

Explanation of symbols

20 Relief valve 21 Switching valve disc (valve housing)
21a Valve hole 21b Relief hole 22 Valve seat member (valve seat part)
22b Communication hole 22c Valve seat 23 Ball 24 Ball receiver 24a Small diameter part 25 Relief spring 40 Ball receiver holder 41 Substrate 42 Anti-vibration seal 43 Attaching part 44 Lip part

Claims (5)

The pressure housing discharged from the hydraulic pump is introduced into the valve housing having a valve hole drilled along the axial direction, and one end of the communication hole provided at the opening end of the valve hole and penetrating along the axial direction. And a ball seat that has a valve seat formed at the other end, a ball that contacts the valve seat and closes the communication hole, holds the ball, and slides along the inner surface of the valve hole. A ball receiver that is provided, a relief spring that urges the ball receiver in a direction in which the ball abuts the valve seat, and an inner surface of the valve hole that is attached to the outer periphery of the small-diameter portion of the ball receiver. A relief valve in which a relief hole for relieving pressure oil is opened in the radial direction of the valve hole.
The ball receiving holder has a substrate that contacts the end surface of the small diameter portion of the ball receiver, and a vibration-proof seal that is bonded to the outer edge of the substrate,
An anti-vibration seal is bonded to the substrate at one end and is hugged to the outer periphery of the small-diameter portion of the ball receiver, and from the one end side bonded to the substrate of the hugging portion outward along the radial direction, and It is composed of rubber that has a lip portion that extends to the ball side along the axial direction and that is in sliding contact with the inner surface of the valve hole,
A relief valve characterized in that the rubber hardness of the vibration-proof seal is determined within a range of Hs75 to Hs65. The pressure housing discharged from the hydraulic pump is introduced into the valve housing having a valve hole drilled along the axial direction, and one end of the communication hole provided at the opening end of the valve hole and penetrating along the axial direction. And a ball seat that has a valve seat formed at the other end, a ball that contacts the valve seat and closes the communication hole, holds the ball, and slides along the inner surface of the valve hole. A ball receiver that is provided, a relief spring that urges the ball receiver in a direction in which the ball abuts the valve seat, and an inner surface of the valve hole that is attached to the outer periphery of the small-diameter portion of the ball receiver. A relief valve in which a relief hole for relieving pressure oil is opened in the radial direction of the valve hole.
The ball receiving holder has a substrate that contacts the end surface of the small diameter portion of the ball receiver, and a vibration-proof seal that is bonded to the outer edge of the substrate,
An anti-vibration seal is bonded to the substrate at one end and is hugged to the outer periphery of the small-diameter portion of the ball receiver, and from the one end side bonded to the substrate of the hugging portion outward along the radial direction, and It is composed of rubber that has a lip portion that extends to the ball side along the axial direction and that is in sliding contact with the inner surface of the valve hole,
A relief valve characterized in that the distance formed by the maximum outer diameter portion in the free state of the lip portion of the vibration-proof seal with respect to the end surface on the side not contacting the end surface of the small-diameter portion of the ball receiver is 1.5 mm or more . The pressure housing discharged from the hydraulic pump is introduced into the valve housing having a valve hole drilled along the axial direction, and one end of the communication hole provided at the opening end of the valve hole and penetrating along the axial direction. And a ball seat that has a valve seat formed at the other end, a ball that contacts the valve seat and closes the communication hole, holds the ball, and slides along the inner surface of the valve hole. A ball receiver that is provided, a relief spring that urges the ball receiver in a direction in which the ball abuts the valve seat, and an inner surface of the valve hole that is attached to the outer periphery of the small-diameter portion of the ball receiver. A relief valve in which a relief hole for relieving pressure oil is opened in the radial direction of the valve hole.
The ball receiving holder has a substrate that contacts the end surface of the small diameter portion of the ball receiver, and a vibration-proof seal that is bonded to the outer edge of the substrate,
An anti-vibration seal is bonded to the substrate at one end and is hugged to the outer periphery of the small-diameter portion of the ball receiver, and from the one end side bonded to the substrate of the hugging portion outward along the radial direction, and It is composed of rubber that has a lip portion that extends to the ball side along the axial direction and that is in sliding contact with the inner surface of the valve hole,
A relief valve characterized in that the angle formed by the extending direction of the lip portion of the vibration-proof seal with respect to the direction along the end face of the substrate is set within a range of 60 to 50 degrees. The pressure housing discharged from the hydraulic pump is introduced into the valve housing having a valve hole drilled along the axial direction, and one end of the communication hole provided at the opening end of the valve hole and penetrating along the axial direction. And a ball seat that has a valve seat formed at the other end, a ball that contacts the valve seat and closes the communication hole, holds the ball, and slides along the inner surface of the valve hole. A ball receiver that is provided, a relief spring that urges the ball receiver in a direction in which the ball abuts the valve seat, and an inner surface of the valve hole that is attached to the outer periphery of the small-diameter portion of the ball receiver. A relief valve in which a relief hole for relieving pressure oil is opened in the radial direction of the valve hole.
The ball receiving holder has a substrate that contacts the end surface of the small diameter portion of the ball receiver, and a vibration-proof seal that is bonded to the outer edge of the substrate,
An anti-vibration seal is bonded to the substrate at one end and is hugged to the outer periphery of the small-diameter portion of the ball receiver, and from the one end side bonded to the substrate of the hugging portion outward along the radial direction, and It is composed of rubber that has a lip portion that extends to the ball side along the axial direction and that is in sliding contact with the inner surface of the valve hole,
A relief valve characterized in that the rounded radius of the crossing surface portion where the lip portion of the vibration-proof seal intersects the hugging portion is R0.1 mm or less. The pressure housing discharged from the hydraulic pump is introduced into the valve housing having a valve hole drilled along the axial direction, and one end of the communication hole provided at the opening end of the valve hole and penetrating along the axial direction. And a ball seat that has a valve seat formed at the other end, a ball that contacts the valve seat and closes the communication hole, holds the ball, and slides along the inner surface of the valve hole. A ball receiver that is provided, a relief spring that urges the ball receiver in a direction in which the ball abuts the valve seat, and an inner surface of the valve hole that is attached to the outer periphery of the small-diameter portion of the ball receiver. A relief valve in which a relief hole for relieving pressure oil is opened in the radial direction of the valve hole.
The ball receiving holder has a substrate that contacts the end surface of the small diameter portion of the ball receiver, and a vibration-proof seal that is bonded to the outer edge of the substrate,
An anti-vibration seal is bonded to the substrate at one end and is hugged to the outer periphery of the small-diameter portion of the ball receiver, and from the one end side bonded to the substrate of the hugging portion outward along the radial direction, and It is composed of rubber that has a lip portion that extends to the ball side along the axial direction and that is in sliding contact with the inner surface of the valve hole,
The crossing surface where the extending direction of the lip portion of the vibration-proof seal is defined in the range of 60 to 50 degrees with respect to the direction along the end face of the substrate, and the lip portion of the vibration-proof seal intersects the hugging portion Relief valve characterized in that round radius of the part is R0.1mm or less.

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