JP5369058B2 - Damping valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping valve that can generate a stable damping force at a damper by suppressing the oscillation of a valve body. <P>SOLUTION: The damping valve 1 includes: a housing 2 which communicates with one chamber R1 with the one chamber R1 as an upstream and the other chamber R as a downstream out of the two chambers formed in the damper D, and has a valve hole 3 having a valve seat 4 in the middle; a valve body 5 which is axially and movably inserted into the valve hole 3, and separated from and seated on the valve seat 4; a communication hole 11 opened from the side of the valve hole 3 and communicating with the other chamber R; and a biasing member 6 which biases the valve body 5 toward the valve seat 4 side. In the damping valve, there is arranged a cylindrical collar 7 which is accommodated in the valve hole 3, accommodates the valve body 5 therein, and partitions an annular chamber communicating with the communication hole 11 between the internal periphery of the valve hole 3 and itself, and a throttle hole 8 which makes the annular chamber and the inside of the collar 7 communicate with each other is formed at the collar 7. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an improved damping valve.

  The damping valve is a device that gives resistance to the flow of the working fluid that accompanies expansion and contraction of the shock absorber and exerts a damping force on the shock absorber. For example, a reservoir is formed between the cylinders in a double-tube shock absorber. Used to be incorporated into a rod guide that supports a piston rod that is fitted to both ends of the outer cylinder and is slidably inserted into the cylinder, and to be supported by the piston rod. .

  For example, in a damping valve incorporated in a rod guide of a double cylinder type shock absorber, a valve hole provided in the rod guide and communicated with an upstream cylinder and a downstream reservoir, and a valve hole A valve seat provided on the inner periphery of the valve body, a valve body inserted into the valve hole so as to be movable in the axial direction, and a coil spring for biasing the valve body toward the valve seat side (for example, a patent) Reference 1).

  Further, the multi-cylinder shock absorber divides the rod side chamber and the piston side chamber filled with the working fluid in the cylinder, and only the flow of the working fluid from the piston side chamber toward the rod side chamber, and the piston connected to the piston rod. A check valve that is allowed and a suction valve that allows only a flow of working fluid from the reservoir to the piston side chamber are provided, and the valve hole communicates the rod side chamber in the cylinder and the reservoir.

  This double-cylinder shock absorber discharges the working fluid from the cylinder to the reservoir through the valve hole regardless of whether it is extended or contracted. A damping force is exerted by applying resistance to the flow of the working fluid. Note that the working fluid that is insufficient in the cylinder at the time of extension is supplied into the cylinder via the suction valve.

JP 2002-349629 A

  In this conventional damping valve, the valve body is urged by a coil spring, the valve opening pressure is adjusted by the initial load of the coil spring, and the spring constant of the coil spring is used in the double cylinder type shock absorber. The attenuation characteristic can be adjusted.

  However, in such a damping valve that biases the valve body with a coil spring, if the double-tube shock absorber exhibits high speed operation, that is, if the double-tube shock absorber repeatedly expands and contracts at high speed, There is a problem that the axial vibration of the valve body is excited and oscillates due to the pressure fluctuation, and the damping force generated by the double-cylinder shock absorber becomes unstable and vibrates.

  Therefore, the present invention was devised in order to improve the above-mentioned problems, and the object of the present invention is to provide a damping that can suppress the oscillation of the valve body and generate a stable damping force in the shock absorber. It is to provide a valve.

  In order to achieve the above-described object, the problem solving means of the present invention is configured such that one chamber of the two chambers formed in the shock absorber is in the upstream and the other chamber is in the downstream and communicated with the one chamber. A housing having a valve hole having a valve seat, a valve body inserted in the valve hole so as to be movable in the axial direction and seated on and off from the valve seat, and opened from the side of the valve hole to communicate with the other chamber In a damping valve having a communication hole and a biasing member that biases the valve body toward the valve seat, the damping valve is housed in the valve hole and accommodates the valve body inward and between the inner periphery of the valve hole A cylindrical collar that divides the annular chamber that communicates with the communication hole is provided, and a throttle hole that communicates the annular chamber with the inside of the collar is provided in the collar.

  According to the damping valve of the present invention, even when the shock absorber operates at a high speed that expands and contracts at a high speed, back pressure can be applied to the valve body by the throttle hole, and the axial direction of the valve body can be applied by the back pressure. The problem that the vibration is suppressed and oscillation is prevented, and the damping force generated by the shock absorber becomes stable and vibrational is solved.

It is a longitudinal cross-sectional view of the double cylinder type | mold shock absorber with which the damping valve in one Embodiment was mounted. It is an expansion longitudinal cross-sectional view of the damping valve in one Embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIGS. 1 and 2, the damping valve 1 in one embodiment is provided on a rod guide 2 that is fitted to both ends of a cylinder 20 and an outer cylinder 21 in a double-tube shock absorber D. The rod guide 2 is used as a housing and communicated with a rod side chamber R1 as one chamber, and a valve hole 3 provided with a valve seat 4 is provided in the middle of the rod guide 2, and the rod provided with the valve hole 3 The guide 2, the valve body 5 that is inserted in the valve hole 3 so as to be movable in the axial direction and seated on the valve seat 4, and opens from the side of the valve hole 3 to communicate with the reservoir R as the other chamber. The communication hole 11, the coil spring 6 as an urging member for urging the valve body 5 toward the valve seat 4, and the valve body 5 accommodated in the valve hole 3 and accommodated in the valve hole 3. A cylindrical collar 7 that defines an annular chamber L that communicates with the communication hole 11 between the inner periphery of It is constituted by a throttle hole 8 provided in the chromatography.

  On the other hand, a double-cylinder shock absorber D to which the damping valve 1 is applied includes a cylinder 20, an outer cylinder 21 that forms a reservoir R between the cylinder 20, and a cylinder 20 that is slidably inserted into the cylinder 20. A piston 22 that is divided into a rod-side chamber R1 and a piston-side chamber R2 filled with working oil as working fluid, a piston rod 23 that is movably inserted into the cylinder 20 and connected to the piston 22, and a cylinder The rod guide 2 fitted to both ends of the cylinder 20 and the outer cylinder 21 and pivotally supporting the piston rod 23, the partition member 24 fitted to the lower end of the cylinder 20 in FIG. A lid 25 for closing the middle and lower ends, a piston passage 26 communicating with the piston side chamber R2 and the rod side chamber R1 provided in the piston 22, and a piston passage 26 provided in the piston passage 26 from the piston side chamber R2. A check valve 27 that allows only the flow of hydraulic oil toward the cylinder side chamber R1, a suction passage 28 that is provided in the partition member 24 and communicates the reservoir R and the piston side chamber R2, and a reservoir R that is provided in the suction passage 28. And a suction valve 29 that allows only the flow of hydraulic oil toward the piston side chamber R2. In addition to the working oil, it is possible to employ a working fluid that can be applied to a shock absorber such as gas, water, aqueous solution, electrorheological fluid, and magnetorheological fluid.

  When the double cylinder type shock absorber D is extended and the piston 22 moves upward in FIG. 1, the damping valve 1 is connected to the valve hole 3 and the communication hole 11 from the rod side chamber R1 which is opened and compressed. The hydraulic fluid flows into the reservoir R through the pipe 9 and the resistance of the hydraulic fluid is given by the damping valve 1 so that the rod side chamber R1 is pressurized, and the double cylinder type shock absorber D has a damping force for suppressing the extension operation. Demonstrate. In this extension operation, the piston 22 rises in FIG. 1 to increase the volume of the piston-side chamber R2, but the suction valve 29 provided in the suction passage 28 opens and the hydraulic oil corresponding to the increase is stored in the reservoir R. To the piston side chamber R2.

  Further, when the double cylinder type shock absorber D is contracted and the piston 22 moves downward in FIG. 1, the check valve 27 provided in the piston passage 26 is opened and compressed from the piston side chamber R2 to the rod side chamber R1. As the hydraulic fluid moves to the cylinder 20, the hydraulic fluid corresponding to the volume of the piston rod 23 entering the cylinder 20 becomes excessive in the cylinder 20, so that the damping valve 1 is opened and this excess hydraulic oil is opened. The hydraulic oil flows to the reservoir R through the hole 3 and the pipe 9, and resistance is applied to the flow of the hydraulic oil by the damping valve 1, whereby the overall pressure in the cylinder 20 rises and the double cylinder type shock absorber D is contracted. Demonstrates damping force.

  In other words, the double cylinder type shock absorber D is configured such that the hydraulic oil flows from the rod side chamber R1 through the damping valve 1 to the reservoir R and repeats the expansion and contraction operation during the expansion operation and the contraction operation. The uniflow type shock absorber in which hydraulic oil circulates in the order of the rod side chamber R1, the reservoir R, the piston side chamber R2, and the rod side chamber R1 is set. That is, in this case, one chamber upstream of the damping valve 1 formed in the double-tube shock absorber D is the rod-side chamber R1, and the other chamber downstream is the reservoir R.

  Hereinafter, the damping valve 1 will be described in detail. The rod guide 2 has a cylindrical shape, and the outer periphery is fitted to the inner periphery of the outer cylinder 21 at the upper end in FIG. 1 and the inner periphery is fitted to the outer periphery of the upper end of the cylinder 20 in FIG.

  Further, the inner peripheral diameter of the lower end in FIG. 1 of the rod guide 2 is set to a diameter that can be fitted to the outer periphery of the cylinder 20, and the upper inner periphery in FIG. A recess 2a is formed in which a seal member 30 for sealing is mounted, and a cylindrical bearing 31 slidably in contact with the outer periphery of the piston rod 23 is mounted on the inner periphery and below the recess 2a. In addition, the inner diameter of the intermediate portion 2 b that is the inner circumference of the rod guide 2 and below the mounting portion of the bearing 31 and above the fitting portion of the cylinder 20 is set larger than the outer diameter of the piston rod 23. A gap is formed between the piston rod 23 and the piston rod 23.

  Subsequently, the valve hole 3 provided in the rod guide 2 opens from the outer periphery of the rod guide 2 and passes through the intermediate portion 2 b, and opens from the end of the rod guide 2 facing the reservoir R to reach the middle of the valve hole 3. The communication hole 11 communicates with the reservoir R through the communication hole 11.

  The valve hole 3 has an inner diameter of the intermediate portion 2b of the rod guide 2 and a small diameter portion 3a communicating with the rod side chamber R1, and a large diameter portion having an inner diameter continuous with the small diameter portion 3a larger than the small diameter portion 3a. 3b, an annular valve seat 4 provided on the inner periphery of the step portion 3c between the small diameter portion 3a and the large diameter portion 3b, and a screw portion 3d provided on the inner periphery on the right end in FIG. 2 of the large diameter portion 3b. A collar 7 which will be described later is screwed to the screw portion 3d.

  A communication hole 11 that opens from the middle of the large-diameter portion 3 b of the valve hole 3 to the end facing the reservoir R of the rod guide 2 is provided. The communication hole 11 is also provided with a screw portion 11 a. In addition, the pipe 9 is fixed to the rod guide 2 by screwing a screw 9 a provided on the outer periphery of the upper end of the pipe 9 in FIG. The pipe 9 is protruded and accommodated in the reservoir R, and its lower end opening end in FIG. Therefore, the rod side chamber R1 and the reservoir R of the cylinder 20 are communicated with each other through the valve hole 3, the communication hole 11, and the pipe 9. The pipe 9 may be fixed to the communication hole 11 by press-fitting or welding in addition to screw connection.

  A cylindrical collar 7 is accommodated in the large diameter portion 3 b of the valve hole 3. The collar 7 includes a reduced diameter portion 7a that forms an annular gap with the large diameter portion 3b of the valve hole 3, and a screw portion 3d that is connected to the reduced diameter portion 7a and formed in the large diameter portion 3b of the valve hole 3. A diameter-reduced portion 7 b that is screwed and a throttle hole 8 that is formed in the diameter-reduced portion 7 a and communicates with the inside and outside of the collar 7. The left end is in contact with the stepped portion 3c of the valve hole 3 and the enlarged diameter portion 7b serving as the base end is screwed into the valve hole 3, so that the annular gap is defined in the valve hole 3, and the annular gap is formed in the annular chamber. L is formed.

  The throttle hole 8 provides resistance to the flow of the hydraulic fluid passing therethrough, and generates a differential pressure corresponding to the pressure loss between the pressure in the collar 7 and the annular chamber L. However, the number of installations is arbitrary.

  The reduced diameter portion 7a faces the communication hole 11, and communicates with the annular chamber L without the communication hole 11 being closed. Further, the communication hole 11 and the throttle hole 8 are not opposed to each other, and the installation positions of the throttle hole 8 and the communication hole 11 are shifted in the axial direction as shown in FIG. Since the communication hole 11 and the throttle hole 8 are installed with a shift in the axial direction in this way, it is not necessary to position and fix the collar 7 in the circumferential direction with respect to the valve hole 3, so that assembly processing is easy. However, the throttle hole 8 and the communication hole 11 may be installed with a shift in the circumferential direction so as not to face each other.

  The valve body 5 is accommodated in the collar 7 accommodated in the valve hole 3 so as to be movable in the axial direction of the valve hole 3, is seated on the valve seat 4, and has a disc shape with a notch 5 f on the outer periphery. The valve body 5a, the cylindrical shaft portion 5b formed at the left end in FIG. 2 which is the front side of the valve body 5a, and the spring fitting which protrudes to the right side in FIG. 2 which is the opposite shaft portion side of the valve body 5a A portion 5c, a groove 5d provided in the shaft portion 5b, and an orifice passage 5e leading from the groove 5d to the end of the spring fitting portion 5c are configured.

  The shaft portion 5 b is slidably inserted into the small diameter portion 3 a of the valve hole 3, and the valve body 5 can move in the axial direction without being displaced relative to the valve hole 3 with the shaft portion 5 b as a guide. It can be done. If the gap between the outer periphery of the valve body 5a and the inner periphery of the collar 7 is sufficiently large, the notch 5f provided on the outer periphery of the valve body 5a may be eliminated, but the flow path area is secured by the notch 5f. By doing so, the diameter of the collar 7 can be reduced, and consequently the inner diameter of the valve hole 3 can be reduced, so that the damping valve 1 can be made small.

  When the left end of the valve body 5a in FIG. 2 is brought into contact with the right end surface of the valve seat 4 in FIG. 2 and is seated, the damping valve 1 is closed and the flow of hydraulic oil into the valve hole 3 is blocked. Be able to. Further, the shaft portion 5b is provided with a U-shaped groove 5d from the distal end to the proximal end, and the left end in FIG. 2 of the valve body 5a is from the right end surface in FIG. 2 of the valve seat 4 to the right in FIG. When retreating to the inside of the valve hole 3, the groove 5 d enters the inside of the valve hole 3 from the small diameter portion 3 a according to the retraction amount, the damping valve 1 is opened, and the hydraulic oil enters the valve hole 3 through the groove 5 d. It can be inflowed. The valve opening area of the damping valve 1 increases as the groove 5d enters the valve hole 3 in accordance with the retraction amount of the valve body 5a in the valve body 5. Note that the shape of the shaft portion 5b is not limited to the above-described shape, and in particular, it may not function as a guide for the movement of the valve body 5.

  A spring seat 10 is screwed to the end portion on the outer peripheral side of the rod guide in the enlarged diameter portion 7b of the collar 7 described above. Specifically, the spring seat 10 is screwed to a cylindrical spring fitting portion 10a and a screw portion 7c provided on the outer periphery of the spring fitting portion 10a and provided on the inner periphery of the enlarged diameter portion 7b of the collar 7. And a flange-shaped spring receiving portion 10b.

  Further, a coil spring 6 as an urging member is interposed between the spring seat 10 and the valve body 5. The coil spring 6 is interposed between the spring seat 10 and the valve body 5 in a compressed state, and an initial load is applied. The valve body is energized by the initial load of the compressed coil spring 6. 5 is pressed toward the valve seat 4. In addition, since the energizing member should just energize the valve body 5, elastic bodies other than a coil spring can also be used.

  In this embodiment, the collar 7 is fixed by being screwed to the valve hole 3, and the spring seat 10 is screwed to the collar 7. The initial load applied to the coil spring 6 can be freely adjusted by adjusting the screwing position with respect to. It should be noted that while the length of the large diameter portion 3b of the valve hole 3 is lengthened and the collar 7 is screwed onto the screw portion 3d of the valve hole 3, the rod guide outer periphery from the base end of the collar 7 in the screw portion 3d of the large diameter portion 3b. It is possible to adjust the initial load applied to the coil spring 6 by screwing the spring seat 10 to the side, but the free length of the coil spring 6 is shortened by screwing the spring seat 10 to the collar 7. While being able to set, the full length of the damping valve 1 can be shortened. In this embodiment, the spring seat 10 can adjust the initial load of the coil spring 6. However, the position of the coil spring 6 is determined and the axial position needs to be adjusted. If not, the enlarged diameter portion 7b of the collar 7 is fitted to the large diameter portion 3b of the valve hole 3 without being screwed, and the spring receiving portion 10b of the spring seat 10 is screwed to the screw portion 3d of the large diameter portion 3b. The collar 7 may be clamped between the step portion 3 c of the valve hole 3 and the spring receiving portion 10 b so that the collar 7 is fixed to the valve hole 3.

  In the damping valve 1 configured as described above, the pressure in the rod side chamber R1 acts on the shaft portion 5a of the valve body 5, and the force pushing the valve body 5 biases the valve body 5 of the coil spring 6. When the force is exceeded, the valve opens, and the fluid that has pushed the valve body 5 and passed through the groove 5d passes through the collar 7, the throttle hole 8, the annular chamber L, the communication hole 11 and the pipe 9 and escapes to the reservoir R. Will go.

  As the pressure acting on the distal end side increases, the valve body 5 moves away from the valve seat 4 and the inward movement amount of the valve hole 3 increases. As the reverse movement amount increases, the valve body 5 and the valve seat increase. The valve opening area limited by 4 also increases. Note that the expansion and contraction speed of the double-tube shock absorber D is low, the force pressing the valve body 5 due to the pressure of the rod side chamber R1 acting on the valve body 5 is small, and overcomes the initial load of the coil spring 6 so that the valve body 5 Cannot be separated from the valve seat 4, the hydraulic oil passes through the orifice passage 5 e that connects the groove 5 d in the valve body 5 and the end of the spring fitting portion 5 c to the reservoir R. The multi-cylinder shock absorber D is configured to move and exhibits a damping force with a higher damping coefficient until the valve body 5 is separated from the valve seat 4 than after the valve body 5 is separated. . However, depending on the required attenuation characteristics, the orifice passage 5e may not be provided.

  As described above, the hydraulic oil discharged from the rod side chamber R1 always passes through the gap between the valve body 5 and the valve seat 4 and then passes through the throttle hole 8 provided in the collar 7 to the reservoir R. Will move.

  Therefore, when the double cylinder type shock absorber D exhibits expansion / contraction operation, the hydraulic oil discharged from the rod side chamber R1 pushes the valve body 5, the valve body 5 is separated from the valve seat 4, and the damping valve 1 is opened. Since the flow of the hydraulic oil that has passed between the valve body 5 and the valve seat 4 is throttled by the throttle hole 8, the pressure in the collar 7 becomes higher than that of the reservoir R, and the pressure in the collar 7 is back pressure applied to the valve body 5. Acts as Thus, since the back pressure acts on the valve body 5 by the throttle hole 8 and is pressed to the valve seat 4 side, even when the multi-cylinder shock absorber D operates at a high speed to expand and contract at high speed, The vibration in the axial direction of the valve body 5 is suppressed and oscillation is prevented, and the problem that the damping force generated by the double-tube shock absorber D becomes stable and oscillating is solved.

  Further, in this embodiment, since the throttle hole 8 does not face the communication hole 11, the flow of hydraulic oil flowing from the collar 7 to the annular chamber L through the throttle hole 8 follows from the throttle hole 8 to the communication hole 11. Since the flow velocity is weakened by all means until the flow velocity is reduced, the jet of hydraulic oil that has passed through the throttle hole 8 does not directly enter the reservoir R, and foaming of the hydraulic fluid in the reservoir R can be suppressed. A stable damping force can be generated in the double-tube shock absorber D. It should be noted that even if the throttle hole 8 and the communication hole 11 face each other, the effect of the present invention that the oscillation of the valve element 5 can be prevented is not lost, and the rod side chamber R1 and the reservoir R of the uniflow type multi-tube shock absorber D are not lost. When the damping valve 1 is provided between the throttle hole 8 and the communication hole 11, the foaming of the hydraulic oil in the reservoir R can be suppressed in addition to the effect of the present invention by preventing the throttle hole 8 and the communication hole 11 from facing each other. is there.

  Further, since only the collar 7 is installed, it is not necessary to newly process the housing provided with the valve hole 3, in this case, to the rod guide 2, so that the existing damping valve can be easily and costly. Can be incorporated without

  In the above description, the case where the damping valve 1 of the present invention is incorporated in the double cylinder type shock absorber D has been described as an example. However, the present invention can also be applied to a shock absorber other than the double cylinder type shock absorber. Can be demonstrated. For example, regardless of whether the cylinder is a single cylinder type or a multiple cylinder type, a shock absorber piston can be used as a housing and a damping valve can be incorporated therein. In this case, one chamber is one of a rod side chamber and a piston side chamber, and the other is The damping valve can generate a damping force in the shock absorber when the shock absorber is extended or contracted, with the other chamber being the other of the rod side chamber and the piston side chamber. In addition, when the shock absorber is a double-tube shock absorber and is set to biflow, the piston side chamber is set as one upstream chamber, the reservoir is set as the other downstream chamber, and a damping valve is incorporated in the base valve portion to You may make it exhibit a damping force to a buffer at the time of contraction.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

  The damping valve of the present invention can be used for a shock absorber.

DESCRIPTION OF SYMBOLS 1 Damping valve 2 Rod guide 2a Recessed part 2b Middle part 3 Valve hole 3a Small diameter part 3b in valve hole Large diameter part 3c in valve hole Step part 3d in valve hole Screw part 4 in valve hole 4 Valve seat 5 Valve body 5a Valve in valve body Main body 5b Shaft portion 5c in the valve body Spring fitting portion 5d in the valve body Groove 5e in the valve body Orifice passage 5f in the valve body Notch 6 in the valve body 7 Coil spring 7 as a biasing member 7a Collar 7a Expanded diameter portion 7c Screw portion 8 in collar Collar hole 9 Pipe 9a Screw portion 10 Spring seat 10a Spring fitting portion 10b Spring receiving portion 11 Communication hole 11a Screw portion 20 in communication hole Cylinder 21 Outer cylinder 22 Piston 23 Piston rod 24 Partition member 25 Lid 26 Piston passage 27 Check valve 28 Suction passage 29 Suction valve 30 Seal member 31 Bearing D Double cylinder Type shock absorber L Annular chamber R Reservoir R1 Rod side chamber R2 Piston side chamber

Claims (3)

A housing provided with a valve hole having a valve seat in the middle of the two chambers formed in the shock absorber and having one chamber upstream and the other chamber downstream A valve body that is inserted movably in the axial direction and seats on and off the valve seat, a communication hole that opens from the side of the valve hole and communicates with the other chamber, and biases the valve body toward the valve seat side In a damping valve provided with an urging member, a cylindrical collar is provided that divides an annular chamber that is accommodated in the valve hole, accommodates the valve body inward, and communicates with the inner periphery of the valve hole. A damping valve, wherein the collar is provided with a throttle hole for communicating the annular chamber with the inside of the collar. The damping valve according to claim 1, wherein the throttle hole is provided at a position not facing the communication hole. The valve hole includes a small-diameter portion communicating with one chamber, a large-diameter portion having an inner diameter larger than that of the small-diameter portion, and an annular valve seat provided on the inner edge of the step portion between the small-diameter portion and the large-diameter portion. The collar has a base end screwed to the large-diameter portion and a tip abutting against the stepped portion to partition the annular chamber into the valve hole. Damping valve as described in

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