JP5938818B2 - Relief valve - Google Patents

Description

  The present invention relates to a relief valve, and more particularly to a relief valve incorporating a proportional solenoid.

  A relief valve is a valve used for pressure setting in a hydraulic circuit, and sets a pressure by a spring or a solenoid. That is, when the pressure on the upstream (input port) side exceeds a predetermined pressure, the pressure body separates the valve body from the valve seat against the urging force of the spring or solenoid by this pressure, and pressure oil is supplied to the downstream (output port) side. It is sent out and the hydraulic pressure in the circuit is lowered to keep it at a predetermined pressure. A relief valve set by a solenoid variably controls a set pressure by an input from a proportional solenoid, so that the set pressure can be changed at any time, and is often used for a damper of a vibration reduction device such as a railway vehicle. By the way, in both relief valves that use springs and those that use solenoids, suppression of chattering that occurs when the valve element is separated from the valve seat is one of the problems.

  Hereinafter, a conventional technique for suppressing chattering will be described. FIG. 8 is a cross-sectional view showing the structure of a relief valve according to the prior art. 8, 70 is a relief valve, 71 is a housing, 72 is a valve body holding chamber, 73a is a large diameter portion, 73b is a small diameter portion, 74 is a valve body, 75a is a large diameter portion, 75b is a small diameter portion, and 76 is a spring. , 77 is a seat portion, 78 is a damper chamber, 79a is an input port, and 79b and 79c are output ports.

  FIG. 8 shows a solenoid disclosed in Japanese Patent Laid-Open No. 11-325285. The relief valve 70 includes a valve body 74 held in a valve body holding chamber 72 provided in the housing 71 so as to be able to advance and retract between a closed position and an opened position, and a spring that biases the valve body 74 toward the closed position. 76. The valve body holding chamber 72 includes a large-diameter portion 73a having a large inner diameter and a small-diameter portion 73b having a small inner diameter formed continuously therewith. The valve body 74 includes a large diameter portion 75a and a small diameter portion 75b having diameters corresponding to the large diameter portion 73a and the small diameter portion 73b of the valve body holding chamber 72, respectively. Further, a damper chamber 78 is formed between the large diameter portion 73a of the valve body holding chamber 72 and the small diameter portion 75b of the valve body 74 so as to expand and contract as the valve body 74 advances and retreats. In order to secure an oil passage that flows into and out of 78, a predetermined clearance is provided between the large diameter portion 73a and the small diameter portion 73b and the large diameter portion 75a and the small diameter portion 75b.

  In the above configuration, when the hydraulic pressure applied to the valve body 74 exceeds a predetermined pressure, and the force acting on the valve body 74 exceeds the elastic biasing force of the spring 76, the valve body 74 is separated from the seat portion 77, and the input port 79a communicates with the output ports 79b and 79c. On the other hand, the holding space of the spring 76 expands / contracts as the valve element 74 moves forward / backward, but the damper chamber 78 expands when the valve element 74 moves toward the open position. As a result, oil flows into the damper chamber 78 from the holding space of the spring 76 through the oil passage by the above-described clearance. At this time, the valve body 74 receives a resistance force due to the viscous resistance of the oil and functions as a damper for the valve body 74, so chattering is suppressed.

  However, in the above configuration, if the hydraulic circuit has not been used for a long time or has been disassembled for maintenance and bubbles are generated in the downstream oil passage, the bubbles are crushed so as to crush the bubbles. Oil flows into the oil path suddenly. Since the damper chamber 78 is at a relatively higher pressure than the oil passage with bubbles, the inflow of oil into the damper chamber 78 is not sufficient, and the function as a damper is reduced.

JP 11-325285 A

  In order to solve the above problems, the present invention provides a relief valve having a structure capable of suppressing chattering even when bubbles are generated in a downstream oil passage in a relief valve incorporating a proportional solenoid. The purpose is to provide.

  According to the first aspect of the present invention, there is provided a valve body provided so as to open and close a communication path between an upstream oil passage and a downstream oil passage by contacting and separating from a valve seat, and a part of the valve body Or a sleeve that is inserted and held in a retractable manner, and is directly or indirectly connected to the valve body, and slides along the central axis to bring the valve body into contact with and away from the valve seat. In the relief valve having the plunger provided as described above, the damper chamber formed by the concave portion formed in one or both of the portions facing each other on the peripheral side surface of the valve body and the inner peripheral surface of the sleeve, It is a relief valve characterized by having an orifice formed so as to communicate the oil passage on the upstream side of the communication passage and the damper chamber.

  According to a second aspect of the present invention, in the first aspect of the invention, the sleeve is formed in a substantially cylindrical shape, and an inner diameter of the plunger side portion is larger than an inner diameter of the valve seat side portion. The relief valve is characterized in that the concave portion is formed in a boundary region between these portions.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the valve body is formed in a substantially cylindrical shape, and a diameter of a portion connected to the plunger is the valve seat. It is a relief valve characterized in that it is larger than the diameter of the part on the side of contact and separation, and the recess is formed in the boundary region between these parts.

  The invention according to a fourth aspect is the invention according to the third aspect, wherein the valve body has a side closer to and away from the valve seat than a portion where the concave portion is formed. The first diameter is slightly smaller than the inner diameter and the second diameter is smaller than the first diameter. The valve body is closer to and away from the valve seat than the portion where the recess is formed. The relief valve is characterized in that a peripheral side surface and an inner peripheral surface closer to the valve seat than a portion where the concave portion of the sleeve is formed constitute the orifice.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the communication passage is further formed inside, and a part of the communication passage is part of the valve seat. A space is formed between the sleeve and the communication path component by cutting the entire circumference or a part of the outer peripheral surface of the valve seat side. The relief valve is characterized in that a through-hole communicating with the space and the damper chamber is formed, and the groove and the through-hole constitute the orifice.

  According to the first aspect of the present invention, since the damper chamber and the orifice communicating the upstream oil passage and the damper chamber are provided between the sleeve and the valve body, the upstream oil passage reaches a predetermined pressure. When this happens, the damper chamber can be activated. Further, even when bubbles are generated in the downstream oil passage, a flow of oil flowing from the upstream oil passage into the damper chamber is generated, so that the damper function is not lowered.

  According to the second aspect of the present invention, the step portion formed on the inner peripheral surface of the sleeve is used as the damper chamber in order to reduce oil leakage to the plunger side. Unlike the case where a damper chamber is provided, it is not necessary to have a diameter that takes into account the damper chamber, and there is no obstacle to the miniaturization of the relief valve.

  According to the third aspect of the present invention, the step portion formed on the peripheral side surface of the valve body is used as the damper chamber in order to reduce the leakage of oil to the plunger side. Unlike the case where a damper chamber is provided, it is not necessary to have a diameter that takes into account the damper chamber, and there is no obstacle to the miniaturization of the relief valve.

  According to the invention described in claim 4, since it is not necessary to form a through hole for the orifice in the sleeve, the processing cost of the sleeve can be reduced.

  According to the fifth aspect of the invention, in addition to the orifice between the sleeve and the valve body, the through hole is formed in the sleeve to form the orifice, so that the flow rate of oil flowing into and out of the damper chamber is increased. Can be easily applied to a large relief valve.

It is a fragmentary sectional view which shows the structure of the peripheral part of the communicating path of the relief valve which concerns on the 1st Embodiment of this invention. It is a fragmentary sectional view which shows the state of the peripheral part of a communicating path at the time of valve opening of the relief valve which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the relief valve which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the relationship between the electric current value and hydraulic pressure in the Example of the relief valve which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the relationship between the electric current value and hydraulic pressure in the relief valve used as a comparative example. It is a fragmentary sectional view which shows the structure of the peripheral part of the communicating path of the relief valve which concerns on the 2nd Embodiment of this invention. It is a fragmentary sectional view which shows the structure of the peripheral part of the communicating path of the relief valve which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the relief valve which concerns on a prior art.

  First, the overall configuration of the relief valve according to the first embodiment of the present invention will be described. FIG. 3 is a cross-sectional view showing a relief valve according to the first embodiment of the present invention. In FIG. 3, 10 is a relief valve, 20 is a valve body, 27 is a large diameter portion, 29 is a proximal end portion, 31 is a communication passage member, 32 is a sleeve, 33 is a small diameter portion, 35 is a medium diameter portion, and 36 is a valve. Seat members 38a and 38b are upstream communication passages, 38c are downstream communication passages, 38d is an annular space, 40 is a damper chamber, 41 is a base end portion, 42 is a spring, 43 is a base, 44 is a flange portion, and 45 is a Caulking portion, 46 is a shaft, 47 is a bearing, 49 is an O-ring, 50 is a plunger, 51 is a proximal end portion, 52 is a case, 53 is a caulking portion, 54 is a sleeve, 55 is a bobbin, 56 is a coil, and 57 is a bearing. , 58 are end caps, 59 is a bushing, and 60 is a cable.

  As shown in FIG. 3, the relief valve 10 according to the first embodiment of the present invention is operated by a proportional solenoid, a base 43 is fitted into a case 52, and the base 43 is further connected to the communication path member 31. It has a structure that supports. The case 52 has both a function as a housing that houses components as a proportional solenoid and a function that supports the base 43. That is, the entire case 52 is formed in a substantially bottomed cylindrical shape, and the portion corresponding to the bottom is located on the distal end side of the relief valve 10, and the side without the bottom is located on the proximal end side of the relief valve 10. Yes. Furthermore, the center of the portion corresponding to the bottom is greatly opened, and the base 43 is fitted into this portion. Inside, a bobbin 55 and a coil 56 wound around the bobbin 55 are inserted. Further, the end cap 58 is inserted so as to press the bobbin 55, and is fixed by the caulking portion 53. Therefore, the bobbin 55 and the coil 56 are also fixed. A stepped portion for positioning the end cap 58 is formed near the proximal end opening on the inner peripheral surface of the case 52, and the end cap 58 is caulked in contact with the stepped portion. Yes.

  The end of the coil 56 is connected to the cable 60. The cable 60 is inserted into a bushing 59 fitted to the end cap 58 and led out to the outside through the bushing 59. Further, the outer peripheral surface on the distal end side of the end cap 58 is fitted to the sleeve 54, and the proximal end portion 51 of the base 43 is fitted to the distal end side of the sleeve 54. Therefore, the end cap 58 and the base 43 are integrated with each other via the sleeve 54. A bearing 57 is fitted in the recessed portion of the end cap 58. The bearing 57 supports the base end side of the shaft 46 in a slidable state. The case 52, the bobbin 55, the end cap 58, the bushing 59, and the cable 60 may have any shape, structure, or size as long as they constitute a proportional solenoid. The shape shown in FIG. It is not limited to structure or size.

  The base 43 has a function of supporting the communication path and components that open and close the communication path. That is, as described above, the base end side of the flange portion 44 is located inside the case 52 and is fitted to the sleeve 54. A through hole is formed along the central axis, and a bearing 47 is fitted to the tip side of the through hole. The bearing 47 supports the base end side of the shaft 46 in a slidable state. In addition, a hole having a larger diameter is formed on the distal end side of the through hole. The communication path member 31 having a larger diameter is inserted, and the communication path member 31 is fixed by a caulking portion 45. Further, the base end side of the through hole is a space for sliding the shaft 46 supported by the bearing 47 and the bearing 57. The shaft 50 has a plunger 50 fixed to an intermediate portion thereof. The plunger 50 is fixed to the shaft 46 by caulking cuts formed at both end faces, and is attracted to the base end portion 51 of the base 43 when the coil 56 is energized.

  Further, the configuration related to the communication path such as the communication path member 31 will be described based on a partially enlarged view. FIG. 1 is a partial cross-sectional view showing the structure of the periphery of the communication passage of the relief valve according to the first embodiment of the present invention. In FIG. 1, 21 is a tip portion, 22 is a small diameter portion, 23 is a medium diameter portion, 24 is a small diameter portion, 25 is a medium diameter portion, 26 is a small diameter portion, 28 is a small diameter portion, 30a and 30b are communication holes, and 34 is a communication hole. A large-diameter portion, 37 is a sheet surface, 39 is a base portion, and 48 is a proximal space. FIG. 2 is a partial cross-sectional view showing the state of the periphery of the communication path when the relief valve according to the first embodiment of the present invention is opened. The reference numerals used in FIG. 2 are the same as those in FIGS.

  The communication path member 31 is inserted into a hole having a large diameter on the distal end side of the base 43 and is fixed by a caulking portion 45. Note that an O-ring 49 is provided so as to be interposed between the two in order to waterproof the leakage of oil from the gap between the two. In addition, through holes are formed as communication paths in the central axis direction of the communication path member 31 and in the vertical direction orthogonal to the central axis. Of the through-hole in the vertical direction and the through-hole in the central axis direction, the portion that opens from the vertical through-hole to the tip portion serves as a communication path with the external oil passage. That is, the upstream communication passages 38a and 38b are connected to an upstream oil passage (not shown), and the downstream communication passage 38c is connected to a downstream oil passage (not shown). Furthermore, a portion of the through hole in the central axis direction that opens from the vertical through hole to the base end, that is, the annular space 38 d side, is formed to fit the sleeve 32. A step portion is formed on the proximal end side of the sleeve 32 so that the diameter near the proximal end portion is slightly larger.

  The sleeve 32 slidably holds the valve body 20 and constitutes an orifice. That is, a through hole is formed in the sleeve 32 in the central axis direction, and the valve body 20 is slidably inserted into the through hole. Further, the through hole in the central axis direction has a small diameter portion 33 having a small inner diameter on the distal end side and a medium diameter portion 35 having a larger inner diameter than the small diameter portion 33 on the proximal end side, corresponding to the shape to be described later of the valve body 20. Forming. Further, a large-diameter portion 34 having an inner diameter larger than that of the medium-diameter portion 35 is formed at a portion that becomes a boundary between the small-diameter portion 33 and the medium-diameter portion 35. The large diameter portion 34 constitutes a damper chamber as will be described later. In addition, the magnitude | size of these specific diameters is determined by the flow volume of oil, etc., and can be changed suitably. In addition, a proximal end portion 41 having a larger inner diameter than the middle diameter portion 35 is formed on the most proximal end side. An annular space 38d is formed between the small-diameter portion 33 and the communication path member 31, and is a space in which oil stays.

  The base end portion 41 of the sleeve 32 has a larger diameter on the outer peripheral surface than the medium diameter portion 35, and step portions are formed on the inner peripheral surface and the outer peripheral surface, respectively. A spring 42 is inserted on the inner peripheral surface side of the base end portion 41, and the tip end side of the spring 42 is held in contact with the stepped portion. Further, the stepped portion between the intermediate diameter portion 35 and the base end portion 41 on the outer peripheral surface is a press-fit completion position when the sleeve 32 is press-fitted into the communication path member 31 and fitted. In addition, the outer peripheral surface of the base end portion 41 is in pressure contact with the O-ring 49, and oil is sealed at this portion. Further, a stepped portion is also formed on the outer peripheral surface between the small diameter portion 33 and the medium diameter portion 35 of the sleeve 32, and oil leakage to the shaft 46 side is reduced by these two stepped portions.

  The valve body 20 is slidably disposed inside the through hole of the sleeve 32, and from the distal end side, the distal end portion 21, the small diameter portion 22, the medium diameter portion 23, the small diameter portion 24, the medium diameter portion 25, and the small diameter. The portion 26, the large diameter portion 27, the small diameter portion 28, and the base end portion 29 are configured in this order. The distal end portion 21 contacts and separates from the seat surface 37 of the valve seat member 36 fitted to the communication passage member 31, and opens and closes between the upstream communication passages 38a and 38b and the downstream communication passage 38c. As shown in FIG. 2, it literally functions as a valve body. The small diameter part 22, the medium diameter part 23, the small diameter part 24, and the medium diameter part 25 are arranged between these peripheral side surfaces and the inner peripheral surface of the small diameter part 33 of the sleeve 32 by alternately arranging portions having different diameters. An orifice is formed. For example, the gap between the peripheral side surface of the small diameter portion 22 and the small diameter portion 24 and the inner peripheral surface of the small diameter portion 33 is 0.2 to 0.4 mm, and the inner peripheral surface of the medium diameter portion 23, the medium diameter portion 25, and the small diameter portion 33. And a gap of 1.0 to 1.4 mm. By comprising in this way, the upstream communication path 38a and the damper chamber 40 mentioned later are connected. Therefore, it is not necessary to separately form a through hole in the sleeve 32, and the manufacturing cost of the relief valve is not increased.

  Further, as shown in FIG. 1, when the distal end portion 21 is in contact with the seat surface 37 of the valve seat member 36, the peripheral side surface of the small diameter portion 26 of the valve body 20 and the inner peripheral surface of the small diameter portion 33 of the sleeve 32 Are opposed to each other with a predetermined gap, and this region constitutes the damper chamber 40. When the damper chamber 40 is in a valve-opened state, the area of the regions facing each other with a predetermined gap is increased, in other words, the capacity of the damper chamber 40 is increased. A small-diameter portion 28 is formed on the base end side of the large-diameter portion 27, and a base end portion 29 is further formed on the base end side. The base end portion 29 has a larger diameter than the large diameter portion 27 and is formed in a bowl shape. Further, the spring 42 is compressed between the stepped portion on the inner peripheral surface side of the base end portion 41 of the sleeve 32 and the base end portion 29, and the center axis thereof is positioned as the center axis of the valve body 20. Is arranged. Since the sleeve 32 is fixed to the base 43 via the communication path member 31, the urging force of the valve body 20 is always applied to the shaft 46 side by the spring 42. Further, the valve body 20 is formed with a communication hole 30 a penetrating the central axis and a communication hole 30 b penetrating in the vertical direction in the small diameter portion 28. The communication holes 30a and 30b relieve the pressure difference between the proximal space 48 and the vicinity of the small-diameter portion 28 and the downstream communication passage 38c so that the operating speed of the valve body 20 does not slow down when the valve is closed. is there.

  In the above configuration, when the current value to the coil 56 is decreased and the urging force of the spring 42 overcomes the force from the plunger 50, the valve body 20 opens away from the seat surface 37, that is, as shown in FIG. The state becomes the state shown in FIG. At this time, as the capacity of the damper chamber 40 increases, the oil flows into the damper chamber 40 from the upstream communication path 38a through the orifice oil passage. Therefore, since the rapid operation of the valve body 20 is hindered by the viscous resistance of the oil, chattering is suppressed. Further, when operating in the reverse direction, the force by which the plunger 50 is attracted to the base 43 overcomes the urging force of the spring 42, and the valve body 20 is pressed against the shaft 46. Then, the valve body 20 comes into contact with the seat surface 37 and closes.

  An experiment for confirming chattering suppression in the relief valve according to the first embodiment of the present invention described above will be described. FIG. 4 is a sectional view showing the relationship between the current value and the hydraulic pressure in the example of the relief valve according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing the relationship between the current value and the hydraulic pressure in a relief valve as a comparative example.

  The relief valve disclosed in FIG. 1, FIG. 2 and FIG. 3 is used as an example, and has the same structure as the relief valve of this example, but the small diameter portion 26 of the valve body 20 and the small diameter portion 33 of the sleeve 32 are formed. A relief valve having a configuration in which the damper chamber 40 does not exist is used as a comparative example. Then, the current value of the coil was increased from 0 to a predetermined value, and in the process until it returned to 0 again, the pressure in the upstream oil passage at the time of valve opening was measured. As a result, in the example, as shown in FIG. 4, the pressure changed smoothly and chattering did not occur. On the other hand, in the comparative example, as shown in FIG. 5, a change in pressure that pulsates when the pressure is about 2.5 Mpa or more, that is, chattering continuously occurred. Therefore, it was confirmed that the embodiment disclosed in FIGS. 1, 2 and 3 has an effect of considerably suppressing chattering.

  As described above, since the relief valve 10 according to the first embodiment of the present invention is provided with the damper chamber 40, the valve body 20 is caused by the viscous resistance of the oil when the oil flows into the damper chamber 40. Receive resistance. Therefore, it is possible to provide a relief valve in which fine vibration of the valve body 20 is suppressed by this resistance and chattering is suppressed. In addition, the relief valve 10 according to this embodiment includes the damper chamber 40 and the upstream communication passages 38a and 38b, the small diameter portion 22, the medium diameter portion 23, the small diameter portion 24, the peripheral surface of the medium diameter portion 25, and the sleeve 32. The small diameter portion 33 communicates with the inner peripheral surface of the small-diameter portion 33 by an orifice, so that bubbles are formed in the downstream oil passage as in the prior art in which the downstream oil passage and the damper chamber communicate with each other. When it occurs, it can be prevented that the oil suddenly flows toward the oil passage with the bubbles so as to crush the bubbles, and the inflow of the oil into the damper chamber is not sufficient. Further, the damper chamber 40 is formed using a stepped portion between the small diameter portion 26 and the large diameter portion 27 of the valve body 20 and a stepped portion between the small diameter portion 33 and the medium diameter portion 35 of the sleeve 32. This is more advantageous in terms of manufacturing cost than in the case of forming a space that becomes a damper chamber by cutting a part of the valve body 20 and the like, and does not hinder downsizing of the relief valve.

  Furthermore, a relief valve according to a second embodiment of the present invention will be described. FIG. 6 is a partial cross-sectional view showing the structure of the periphery of the communication passage of the relief valve according to the second embodiment of the present invention. In FIG. 6, 61 is a medium diameter part, and other code | symbol shows the same thing as FIG.

  In the relief valve according to the second embodiment of the present invention, the small diameter portion 24 of the relief valve 10 according to the first embodiment of the present invention is omitted, and the medium diameter portions 23 and 25 are integrated. 61. Other configurations of the relief valve according to this embodiment are the same as those of the relief valve 10 according to the first embodiment. With the above configuration, depending on the oil flow rate required for the relief valve, a part of the configuration can be simplified compared to the relief valve 10 according to the first embodiment, and the manufacturing cost can be reduced. .

  Subsequently, a relief valve according to a third embodiment of the present invention will be described. FIG. 7 is a partial cross-sectional view showing the structure of the periphery of the communication passage of the relief valve according to the second embodiment of the present invention. In FIG. 7, 62 is an orifice, and other reference numerals are the same as those in FIG.

  In the relief valve according to the third embodiment of the present invention, in the structure of the relief valve 10 according to the first embodiment of the present invention, a through hole is formed in the small diameter portion 33 of the sleeve 32, and the damper chamber 40 and A new orifice 62 communicating with the annular space 38d is provided. Other configurations of the relief valve according to this embodiment are the same as those of the relief valve 10 according to the first embodiment. With the above configuration, when the flow rate of oil required for the relief valve is larger than that of the relief valve 10 according to the first embodiment, it is possible to cope with a larger flow rate by providing the orifice 62. Become.

  The present invention is not limited to the contents described above. For example, depending on the specifications of the relief valve, either the small diameter portion 26 of the valve body 20 or the large diameter portion 34 of the sleeve 32 is not provided. The damper chamber 40 may be formed. That is, in the relief valve 10 according to the first embodiment of the present invention, recesses are formed on both the peripheral side surface of the valve body 20 and the inner peripheral surface of the sleeve 32, and these recesses serve as the damper chamber 40. The recess may be formed only in one of the portions of the peripheral side surface of the valve body and the inner peripheral surface of the sleeve facing each other, and this recess may be used as a damper chamber. Further, in the relief valve 10 according to the third embodiment of the present invention, the small diameter part 22, the medium diameter part 23, the small diameter part 24, and the medium diameter part 25 are arranged by alternately arranging portions having different diameters. Instead of forming an orifice between the peripheral side surface and the inner peripheral surface of the small diameter portion 33 of the sleeve 32, only the orifice 62 may be provided. Further, when the orifice 62 is not provided, a configuration in which the annular space 38d is not provided may be employed. Alternatively, the valve body 20 side portion of the plunger 50 may be formed in a shaft shape without providing the shaft 46, and the valve body 20 may be directly pressed by the plunger 50. Thus, various modifications can be made without departing from the scope described in each claim.

DESCRIPTION OF SYMBOLS 10 Relief valve 20 Valve body 21 Tip part 22 Small diameter part 23 Medium diameter part 24 Small diameter part 25 Medium diameter part 26 Small diameter part 27 Small diameter part 27 Large diameter part 28 Small diameter part 29 Base end part 30a Communication hole 30b Communication hole 31 Communication path member 32 Sleeve 33 Small diameter portion 34 Large diameter portion 35 Medium diameter portion 36 Valve seat member 37 Seat surface 38a Upstream communication passage 38b Upstream communication passage 38c Downstream communication passage 38d Annular space 39 Base portion 40 Damper chamber 41 Base end portion 42 Spring 43 Base 44鍔 part 45 caulking part 46 shaft 47 bearing 48 base end side space 49 O-ring 50 plunger 51 base end part 52 case 53 caulking part 54 sleeve 55 bobbin 56 coil 57 bearing 58 bushing 59 cable 60 end cap 61 medium diameter part 62 orifice 70 Relief valve 71 Housing 72 Valve body holding chamber 73a Large diameter portion 73b Small diameter 74 the valve body 75a a large-diameter portion 75b small diameter portion 76 the spring 77 seat portion 78 damper chamber 79a input port 79b output port 79c output port

Claims (4)

A valve body provided to open and close the communication path between the upstream oil passage and the downstream oil passage by contacting and separating from the valve seat, and a part or all of the valve body can be inserted and stored And a plunger that is connected directly or indirectly to the valve body and that slides along a central axis to bring the valve body into and out of contact with the valve seat. In relief valve,
A damper chamber formed by a recess formed in one or both of the portions facing each other on the peripheral side surface of the valve body and the inner peripheral surface of the sleeve;
An orifice formed so as to communicate the oil passage upstream of the communication path and the damper chamber;
The sleeve is formed in a substantially cylindrical shape, and an inner diameter of the plunger side portion is larger than an inner diameter of the valve seat side portion, and the concave portion is formed in a boundary region between these portions. Relief valve characterized by   The valve body is formed in a substantially cylindrical shape, and a diameter of a portion connected to the plunger is larger than a diameter of a portion on the side contacting and separating from the valve seat, and a boundary region between these portions The relief valve according to claim 1, wherein the concave portion is formed in the relief valve. The valve body has a first diameter slightly smaller than an inner diameter of the valve seat side portion of the sleeve, and a side closer to and away from the valve seat than a portion where the concave portion is formed, and the first diameter. Is made of a smaller second diameter,
A peripheral side surface closer to and away from the valve seat than a portion where the concave portion of the valve body is formed, and an inner peripheral surface of the sleeve which is closer to the valve seat side than the portion where the concave portion is formed constitute the orifice. The relief valve according to claim 2, wherein the relief valve is provided. Further, the communication path is formed inside, and a part of the communication path has a communication path component configured to constitute the valve seat,
The sleeve is formed so as to communicate a space between the communication path constituent member formed by cutting the entire circumference or a part of the outer peripheral surface of the valve seat side, and the space and the damper chamber. and a through-hole, the relief valve according to any one of claims 1 to 3 wherein the through hole formed in said sleeve, characterized in that it constitutes a separate orifice.

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