JP2012013119A - Damping valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damping valve that can generate a stable damping force at a multi-cylinder type damper by suppressing the oscillation of a valve body.SOLUTION: The damping valve 1 includes: a valve hole 3 which is formed at a rod guide 2 pivoting a piston rod 23 connected to a piston 22 which is mated with a cylinder 20 in the multi-cylinder type damper D and both ends of an outer cylinder 21 forming a reservoir R between the cylinder 20 and itself, and slidably inserted into the cylinder 20, and communicates with the inside of the cylinder 20; a pipe 9 which is attached to the rod guide 2, protrudes into the reservoir R, and makes the valve hole 3 and the reservoir R communicate with each other; a valve seat 4 arranged at the internal periphery of the valve hole 3; the valve body 5 which is axially and movably inserted into the valve hole 3, and separated from and seated on the valve seat 4; and an biasing member 6 which biases the valve body 5 toward the valve seat side. An orifice 8 is formed between the valve hole 3 and the reservoir R.

Description

  The present invention relates to an improvement of a damping valve used in a double cylinder type shock absorber.

  The damping valve 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. A rod guide that pivotally supports a piston rod that is fitted to both ends of an outer cylinder that forms a reservoir between cylinders in a shock absorber and that is slidably inserted into the cylinder. What is incorporated is known (see, for example, Patent Documents 1 and 2).

  More specifically, the damping valve is provided in the rod guide in the double cylinder type shock absorber and communicates with the cylinder, and is attached to the rod guide and protrudes into the reservoir to communicate the valve hole and the reservoir. A pipe, a valve seat provided on the inner periphery of the valve hole, a valve body that is inserted into the valve hole so as to be movable in the axial direction, and a coil spring that biases the valve body toward the valve seat side. Yes.

  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 JP 11-344068 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 to improve the above-described problems, and the object of the present invention is to suppress the oscillation of the valve body and generate a stable damping force in the double-tube shock absorber. It is to provide a damping valve capable of

  In order to achieve the above-mentioned object, the problem solving means of the present invention is to slide into the cylinder by fitting to both ends of the outer cylinder forming a reservoir between the cylinders in the double cylinder type shock absorber. A valve hole that is provided in a rod guide that pivotally supports a piston rod that is connected to a piston that is freely inserted, and that communicates with a cylinder; a valve hole that is attached to the rod guide and protrudes into the reservoir; A pipe that communicates with each other, a valve seat provided on the inner periphery of the valve hole, a valve body that is inserted in the valve hole so as to be movable in the axial direction, and is seated on and off from the valve seat, and the valve body is directed toward the valve seat An attenuation valve including an urging member for urging is characterized in that an orifice is provided between a valve hole and a reservoir.

  According to the damping valve of the present invention, the back pressure can be applied to the valve body by the orifice even when the multi-cylinder shock absorber operates at a high speed that expands and contracts at a high speed. Oscillation is prevented by suppressing the axial vibration, and the problem that the damping force generated by the double-tube shock absorber becomes stable and oscillating 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. A valve hole 3 communicating with the rod side chamber R1 in the cylinder 20 and a valve hole 3 attached to the rod guide 2 and projecting into a reservoir R formed between the cylinder 20 and the outer cylinder 21 and the reservoir R A pipe 9 that communicates with the valve hole 3, a valve seat 4 provided on the inner periphery of the valve hole 3, a valve body 5 that is inserted into the valve hole 3 so as to be movable in the axial direction and is seated on and off from the valve seat 4, and a valve body And a coil spring 6 as an urging member for urging 5 toward the valve seat 4, and an orifice 8 provided between the valve hole 3 and the reservoir R.

  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 shock absorber D is extended and the piston 22 moves upward in FIG. 1, the damping valve 1 is opened and compressed from the rod side chamber R1 through the valve hole 3 and the pipe 9 to the reservoir. The hydraulic oil flows to R, and resistance is applied to the flow of the hydraulic oil by the damping valve 1 so that the rod-side chamber R1 is pressurized, and the double-cylinder shock absorber D exhibits a damping force that suppresses the extension operation. 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, in this double cylinder type shock absorber D, the hydraulic oil flows through the damping valve 1 to the reservoir R regardless of whether it is in the expansion operation or in the contraction operation, and the expansion and contraction operation is repeated. A uniflow type shock absorber that 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.

  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. It communicates with the reservoir R through a vertical hole 11 leading to

  Further, the valve hole 3 has a small diameter portion 3a having a smaller diameter on the inner peripheral side of the rod guide 2 than the vertical hole 11, and an annular shape provided on the inner peripheral edge of the end of the small diameter portion 3a inside the valve hole 3. 2 and a screw portion 3b provided on the inner periphery of the right end in FIG. 2, and a spring seat 10 is screwed to the screw portion 3b.

  Further, a screw part 11a is also provided in the vertical hole 11 formed in the rod guide 2, and the screw part 9a provided on the outer periphery of the upper end in FIG. A pipe 9 is fixed to the guide 2, and 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 via the valve hole 3 and the pipe 9. The pipe 9 may be fixed to the vertical hole 11 by press-fitting or welding other than screw connection.

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

  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. In addition, the movement of the valve body 5 may be guided by sliding the outer periphery of the valve body 5a to the inner peripheral surface of the valve hole 3. Further, if the clearance between the outer periphery of the valve body 5a and the valve hole 3 is sufficiently large, the notch 5f provided on the outer periphery of the valve body 5a may be eliminated, but the flow passage area is secured by the notch 5f. Thus, the inner diameter of the valve hole 3 can be reduced, and 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.

  In addition to the valve body 5, a spring seat 10 is accommodated in the outer end of the rod guide 2 in the valve hole 3. Specifically, the spring seat 10 includes a cylindrical spring fitting portion 10 a and a spring receiving portion 10 b that is provided on the outer periphery of the spring fitting portion 10 a and is screwed to the screw portion 3 b of the valve hole 3. It is configured.

  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.

  Therefore, the damping valve 1 opens when 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 exceeds the urging force that urges the valve body 5 of the coil spring 6. Then, the fluid that has pushed through the valve body 5 and passed through the groove 5d passes through the valve hole 3, the vertical hole 11, and the pipe 9, and escapes to the reservoir R.

  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.

  In turn, the orifice piece 7 is attached to the end portion of the vertical hole side which is the upper end of the pipe 9 in FIG. The orifice piece 7 is cylindrical and forms an orifice 8 at the inner periphery and is fitted into a pipe 9 and is provided on the outer periphery of the upper end of the piece body 7a in FIG. A flange 7b having a diameter smaller than the inner diameter of the hole 11 and larger than the inner diameter of the pipe 9 is provided.

  When the piece body 7a of the orifice piece 7 is fitted to the valve hole 3 side which is the upper end of the pipe 9 in FIG. 2, the flange 7b faces the upper end surface of the pipe 9, so that the orifice piece 7 is completely inside the pipe 9. There is no entry and exit. In the case of this embodiment, the spring receiving portion 10b screwed into the screw portion 3b formed in the valve hole 3 of the spring seat 10 interferes with a part of the opening of the vertical hole 11 with respect to the valve hole 3. When the pipe 9 is attached to the screw portion 11a of the vertical hole 11 so as to face the rod guide outer peripheral side end of the opening, even if the orifice piece 7 tries to escape from the pipe 9 upward in FIG. This prevents the orifice piece 7 from falling out of the pipe 9 by abutting against the side portion and restricting upward movement. The orifice piece 7 may be fixed to the pipe 9 by press-fitting the piece body 7 a of the orifice piece 7 into the pipe 9.

  By providing the orifice piece 7 in this way, the hydraulic oil discharged from the rod side chamber R1 passes through the gap between the valve body 5 and the valve seat 4 and then passes through the orifice 8 and through the pipe 9 to the reservoir. Move to R.

  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 orifice 8, the pressure in the valve hole 3 becomes higher than that of the reservoir R, and the pressure in the valve hole 3 is against the valve body 5. Acts as pressure. Thus, since the back pressure acts on the valve body 5 by the orifice 8 and is pressed toward the valve seat 4 side, even when the multi-cylinder shock absorber D operates at a high speed to expand and contract at a high speed, The vibration of the body 5 in the axial direction 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.

  In this embodiment, since the orifice piece 7 having the orifice 8 is mounted on the pipe 9, it is not necessary to process the pipe 9 or the rod guide 2 to install the orifice 8, and the existing damping is performed. The orifice 8 can be incorporated into the valve easily and without cost.

  Further, since the spring seat 10 faces a part of the vertical hole 11 and the orifice piece 7 having the flange 7b is attached to the end of the pipe 9 on the side of the vertical hole, the orifice piece 7 is attached to the valve hole 3. It does not enter the inside and interfere with the valve body 5 or slip through the pipe 9 and fall into the reservoir R.

  As described above, the orifice piece 7 may be attached to the end of the pipe 9 on the side of the vertical hole. However, the effect of the present invention can be obtained even if attached to the end of the pipe 9 on the side of the reservoir. The inner diameter of a part of 9 may be set to a small diameter to provide a small diameter portion, and an orifice may be formed by the small diameter portion. Thus, when providing a small diameter part in the pipe 9, the process which squeezes a part of pipe 9 should just be carried out. Furthermore, it is also possible to employ a configuration in which an orifice is provided by setting a part of the vertical hole 11 to a small diameter. Furthermore, the disc-shaped orifice piece may be sandwiched between the vertical hole side end of the pipe 9 and the spring seat 10 as a disc having a hole functioning as an orifice.

  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 double cylinder type 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 a valve hole Screw part 4 in a valve hole 4 Valve seat 5 Valve body 5a Valve body 5b in a valve body Shaft part 5c in a valve body Spring fitting in a valve body Joint portion 5d Groove 5e in valve body Orifice passage 5f in valve body Notch 6 in valve body 6 Coil spring 7 as urging member Orifice piece 7a Piece body 7b in orifice piece オ リ フ ィ ス 8 in orifice piece Orifice 9 Pipe 9a Screw part 10 Spring seat 10a Spring fitting portion 10b Spring receiving portion 11 Vertical hole 11a Screw portion 20 in the vertical 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 R Reservoir R1 Rod side chamber R2 Piston side chamber

Claims (3)

A piston rod connected to a piston that is fitted into both ends of an outer cylinder that forms a reservoir between the cylinders in the double cylinder type shock absorber and is slidably inserted into the cylinder is pivotally supported. A valve hole provided in the cylindrical rod guide and communicated with the cylinder, a pipe attached to the rod guide and projecting into the reservoir to communicate the valve hole and the reservoir, and provided on the inner periphery of the valve hole A damping valve comprising: a valve seat, a valve body that is inserted in the valve hole so as to be movable in the axial direction and seats on and off the valve seat; and a biasing member that biases the valve body toward the valve seat A damping valve characterized in that an orifice is provided between the valve hole and the reservoir. 2. The damping valve according to claim 1, wherein an orifice piece having a cylindrical shape and having the orifice formed therein is provided, and the orifice piece is attached to a pipe. The pipe is attached to the vertical hole that opens from the end facing the reservoir of the rod guide and communicates with the valve hole, and the orifice piece has a flange on the outer periphery that is larger in diameter than the inner diameter of the pipe. The damping valve according to claim 2, wherein the damping valve is fitted to the portion.

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