JP2008202745A - Valve construction of damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve construction of a damper to be able to satisfy both the driving comfort and stroke length in a vehicle. <P>SOLUTION: The valve construction of the damper comprises a valve disk 1 in which ports 2a, 2b are bored, annular leaf valves 10a, 10b laminate on the valve disk 1 to open and close the ports 2a, 2b, and valve stoppers 11, 12 laminated on the leaf valves 10a, 10b to restrict the deflection amount of he leaf valves 10a, 10b. The valve stoppers 11, 12 comprise plates 11a, 12a having elasticity, laminated on the leaf valves 10a, 10b, and cylinders 11b, 12b brought in contact with the back of the leaf valves 10a, 10b when protruded from the plates 11a, 12b to the leaf valves 10a, 10b sides to deflect the leaf valves by a predetermined amount. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improved valve structure of a shock absorber.

  Conventionally, this kind of shock absorber valve structure is embodied in, for example, a piston portion of a shock absorber for a vehicle, and an annular leaf valve is laminated on the outlet end of a port provided in the piston portion. A valve that opens and closes a port is known.

  In particular, the shock absorber valve structure in which the inner periphery of the leaf valve is fixedly supported and the port is opened and closed by bending the outer periphery side, the damping speed in the high speed region is insufficient and vibration suppression is suppressed. In order to solve this problem, there is a possibility that the riding comfort in the vehicle is impaired, and the inner valve side of the leaf valve L is fixedly supported and the main valve M is supported by the spring S as shown in FIG. Therefore, a valve structure of a shock absorber in which the leaf valve L is urged toward the piston P has been proposed, and is illustrated as an extension side damping valve of the shock absorber (for example, Patent Documents). 1).

In this valve structure, as shown in the figure, when the piston speed when the piston P moves upward is in the low speed region, the outer peripheral side of the leaf valve L is supported by the main valve M stacked on the leaf valve L. Since it bends as a fulcrum, it can be expected to exhibit a higher damping force than a normal valve structure in which the inner periphery is fixedly supported, and when the piston speed reaches a high speed region and the leaf valve L bends greatly, the spring Since S is compressed, the force for urging the leaf valve L toward the piston P is also increased, and compared with a normal valve structure in which the urging force of the spring S is not superimposed, the damping is also large even when the piston speed is in a high speed region. It is expected that the power will be exerted, and the ride comfort in the vehicle can be improved.
Japanese Patent Laying-Open No. 2004-190716 (FIG. 4)

  However, in the proposed valve structure as described above, although it is a useful technique in terms of improving riding comfort in a vehicle, it may be pointed out that there are the following problems.

  Here, in order to improve the riding comfort in the vehicle, it is preferable to reduce the damping coefficient as much as possible when the piston speed is in the middle speed range so that the generated damping force does not become excessive. In the structure, since a larger urging force acts on the leaf valve L due to the compression of the spring S, the damping force becomes excessive even when the piston speed is in the middle speed region, thereby impairing the riding comfort in the vehicle. End up.

  In order to solve these problems, it is necessary to set the spring constant of the spring S small while keeping the initial load for urging the leaf valve L by the spring S as it is.

  However, if the spring S is set as described above, the damping force will be insufficient when the piston speed is in the high speed region, and vibration may not be sufficiently suppressed. is there.

  In order to satisfy the condition of reducing the spring constant while maintaining the initial load of the spring S as it is, it is necessary to set the free length of the spring S long and set the wire diameter small. The length of the whole piston part including the valve becomes longer due to the increase in the natural length, and the stroke length that is the extendable range of the shock absorber is shortened by that length. The overall length becomes long, and the mountability to the vehicle deteriorates.

  Therefore, the present invention was devised to improve the above-described problems, and the object of the present invention is to provide a shock absorber capable of satisfying both the riding comfort in a vehicle and the stroke length in the shock absorber. It is to provide a valve structure.

  In order to solve the above-described object, the problem-solving means in the present invention includes a valve disk in which a port is formed, an annular leaf valve that is stacked on the valve disk and opens and closes the port, and a leaf valve that is stacked on the leaf valve. In the valve structure of the shock absorber provided with a valve stopper that suppresses the valve stopper, the valve stopper is elastically stacked on the leaf valve, and the leaf valve protrudes from the plate toward the leaf valve side and the leaf valve is bent by a predetermined amount. And a cylindrical portion that comes into contact with the back surface of the first and second surfaces.

  According to the valve structure of the shock absorber of the present invention, it is possible to increase the damping coefficient in the high speed region while the piston speed is set to a low damping coefficient in the medium speed region. There is no excess or deficiency in the generated damping force, and the riding comfort in the vehicle can be improved.

  In addition, this valve structure does not require a spring for energizing the leaf valve, and does not increase the natural length of the spring, and the axial length of the piston part including the valve structure is increased. Therefore, there is no problem that the stroke length, which is the extendable range of the shock absorber, is shortened, and the mounting property on the vehicle is not deteriorated.

  In addition, since the configuration that urges the back of the leaf valve with a spring is not adopted, there is no concern that the damping characteristics of each product will vary due to variations in the urging force of the spring. Reliability and stability are improved.

The valve structure of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a part of a piston portion of a shock absorber in which a valve structure according to an embodiment is embodied. FIG. 2 is a diagram illustrating a damping characteristic in a shock absorber in which the valve structure of the shock absorber according to the embodiment is embodied.

  As shown in FIG. 1, the valve structure of the shock absorber in one embodiment is embodied in both the expansion side and pressure side damping valves of the piston portion of the shock absorber. Piston 1 which is a valve disc having a port 2a on one side and a port 2b on the other side which separates the chamber 42 and communicates the one chamber 41 and the other chamber 42, and is laminated on the side surface of the one chamber of the piston 1 One side leaf valve 10a that opens and closes the one side port 2a, the other side leaf valve 10b that is stacked on the other chamber side surface of the piston 1 and opens and closes the other side port 2b, and the one side leaf valve 10a The other side of the valve stopper 11 that suppresses the bending of the leaf valve 10a and the other side of the leaf valve 10b that suppresses the bending of the leaf valve 10b. It is constituted by a valve stopper 12.

  On the other hand, a shock absorber in which the valve structure is embodied is well known and will not be described in detail, but specifically, for example, a cylinder 40 and a head member (not shown) that seals the upper end of the cylinder 40. ), A piston rod 5 slidably passing through a head member (not shown), a piston 1 inserted through the tip 5a of the piston rod 5 and fixed to the tip 5a, and a piston 1 in the cylinder 40 The one chamber 41 on the upper side in FIG. 1 and the other chamber 42 on the lower side in FIG. 1, a sealing member (not shown) that seals the lower end of the cylinder 40, and the volume of the piston rod 5 that protrudes and retracts from the cylinder 40. The cylinder 40 is provided with a reservoir or an air chamber (not shown) that compensates for the minute volume change in the cylinder, and the cylinder 40 is filled with a fluid, specifically, hydraulic oil.

  In the valve structure, when the piston 1 moves up and down in FIG. 1 with respect to the cylinder 40, the hydraulic oil exchanges between the one chamber 41 and the other chamber 42 via the ports 2a and 2b. In addition, the leaf valves 10a and 10b corresponding to the flow of the hydraulic oil are given resistance to cause a predetermined pressure loss, thereby functioning as a damping force generating element for generating a predetermined damping force in the shock absorber.

  Hereinafter, the valve structure will be described in detail. The piston 1 serving as a valve disc is formed in an annular shape and operates in reverse to the port 2a on one side that allows hydraulic oil to pass from the other chamber 42 to the one chamber 41. The other side port 2b that allows oil to pass from the one chamber 41 to the other chamber 42, the windows 3a and 3b respectively connected to the outlet ends of the ports 2a and 2b, and the outlet ends of the ports 2a and 2b Annular valve seats 1a and 1b formed on the outer peripheral sides of the windows 3a and 3b are provided.

  Furthermore, opening windows 6a and 6b are provided at the open ends of the ports 2a and 2b so as not to be blocked by the leaf valves 10a and 10b stacked on the piston 1.

  As described above, the tip 5a of the piston rod 5 of the shock absorber is inserted into the inner peripheral side of the piston 1, and the tip 5a of the piston rod 5 is protruded downward in FIG. The piston rod 5 is a shaft in the shaft member. Further, the outer diameter of the tip 5a of the piston rod 5 is set to be smaller than the outer diameter on the upper side in FIG. 1 from the tip 5a, and a step portion 5b is formed at a portion where the outer diameters of the upper side and the tip 5a are different. Further, a screw groove 5c is formed on the outer periphery of the lower end of the tip 5a in FIG.

  Further, the leaf valves 10a and 10b stacked on the top and bottom of the piston 1 in FIG. 1 are configured as a stacked leaf valve by stacking a plurality of annularly formed plates. The peripheral side is fixed to the tip 5a of the piston rod 5 and abuts against the valve seat 1a formed on the piston 1 to close the outlet end of the port 2a on one side, and the leaf valve 10b on the other side has a piston on the inner peripheral side. It is fixed to the tip 5a of the rod 5 and abuts against a valve seat 1b formed on the piston 1 to close the outlet end of the other port 2b.

  Therefore, the leaf valves 10a and 10b can open the ports 2a and 2b when the inner peripheral side is a fixed end and the outer peripheral side is bent.

  In this embodiment, the leaf valves 10a and 10b are configured as laminated leaf valves. However, the number of the annular plates depends on the damping characteristics (relationship of damping force to piston speed) realized with the valve structure. ), The number of sheets may be one or more depending on the attenuation characteristics generated in the shock absorber, and the outer diameter of each leaf may be set differently depending on the attenuation characteristics generated in the shock absorber. be able to.

  A thick ring r is interposed at one location between the plates constituting the laminated leaf valve of the leaf valve 10a on one side, and is laminated on the upper side in FIG. An initial deflection can be given to the plate group. The deflection amount of the initial deflection can be adjusted by the thickness of the ring r, and the valve opening pressure when the leaf valve 10a leaves the valve seat 1a and opens the port 2a can be adjusted by setting the deflection amount. It has become. Of course, this ring r may be applied to the leaf valve 10b on the other side.

  Further, although not shown in detail, a notch formed on the outer periphery of the leaf valves 10a and 10b seated on the valve seats 1a and 1b or a known orifice formed by being stamped on the valve seats 1a and 1b is provided.

  Subsequently, a spacer 13 and a valve stopper 11 on one side are stacked on the upper side in FIG. 1 from the leaf valve 10a on one side, and a spacer 14 and the other on the lower side in FIG. 1 from the leaf valve 10b on the other side. The valve stopper 12 on the side is laminated, and each of these members is assembled to the tip 5a of the piston rod 5 together with the piston 1, and the piston nut 15 and the piston rod 5 are screwed into the screw groove 5c provided in the tip 5a. It is clamped by the part 5 b and fixed to the piston rod 5.

  That is, in this valve structure, the configuration of the leaf valve 10a, the spacer 13 and the valve stopper 11 arranged on the upper side of the piston 1, and the leaf valve 10b and the spacer 14 arranged on the lower side of the piston 1 are provided. The configuration of the valve stopper 12 is in a line-symmetric relationship with the piston 1 as a border and upside down.

  The one-side valve stopper 11 includes an annular plate 11a stacked on the leaf valve 10a via a spacer 13, and a cylindrical portion 11b that hangs from the outer periphery of the plate 11a and protrudes toward the one-side leaf valve 10a. And is configured.

  The plate 11a is formed by stacking a plurality of perforated thin plate members p, and the plate member p disposed at the lowermost position in FIG. 1 holds the cylindrical portion 11b. Each of these plate members p has elasticity and the inner peripheral side is fixed to the piston rod 5 so that the outer peripheral side can be bent with a predetermined bending rigidity. Therefore, the bending rigidity of the plate 11a is In this case, all of the bending rigidity of the laminated plate members p are combined, and in this case, it is proportional to the number of laminated plate members p.

  The plate member p may not be stacked to form the plate 11a, but may be formed of a single annular plate. In the present embodiment, the thin plate member p is stacked as described above. Thus, since the plate 11a is configured, the bending rigidity of the plate 11a can be adjusted by the number of stacked plate members p, and the adjustment of the bending rigidity of the plate 11a becomes very simple.

  In the present embodiment, the inner diameter of the cylindrical portion 11b is set to a diameter that allows the leaf valve 10a on one side to be in contact with the leaf valve 10a while being bent by a predetermined amount. When stacked on the valve 10a, the lower surface in FIG. 1 of the cylindrical portion 11b is opposed to the outer periphery of the rear surface of the leaf valve 10a, which is the upper surface in FIG. Note that the inner diameter of the cylindrical portion 11b may be set to be smaller than the outer diameter of the leaf valve 10a and may be in contact with the bent middle portion of the leaf valve 10a.

  Subsequently, the valve stopper 12 on the other side includes an annular plate 12a stacked on the leaf valve 10b via the spacer 14, and a cylindrical portion 12b that rises from the outer periphery of the plate 12a and protrudes toward the leaf valve 10b on the other side. And is configured. Also, the plate 12a in the valve stopper 12 is configured by laminating a plurality of perforated thin plate members p like the plate 11a, and the plate member p disposed at the top in FIG. The cylindrical portion 12b is held. Further, the inner diameter of the cylindrical portion 12b is set to a diameter that allows the leaf valve 10b on the other side to be in contact with the leaf valve 10b with a predetermined amount of deflection, and when the valve stopper 12 is stacked on the leaf valve 10b, the cylindrical portion 12b The upper surface of the portion 12b in FIG. 1 is opposed to the back surface of the leaf valve 10b which is the lower surface in FIG. In addition, even if it exists in this cylinder part 12b, you may make it contact | abut to the intermediate part of the leaf valve 10b which set the internal diameter smaller than the outer diameter of the leaf valve 10b, and was bent.

  That is, when the leaf valves 10a and 10b are bent by a predetermined amount, the rear surfaces of the leaf valves 10a and 10b come into contact with the cylindrical portions 11b and 12b. The plates 11a and 12a are also bent, so that the leaf valves 10a and 10b are bent by the combined high bending rigidity obtained by superimposing the bending rigidity of the plates 11a and 12a on the bending rigidity of the leaf valves 10a and 10b, respectively. Therefore, the bending of the leaf valves 10a and 10b is suppressed.

  And since the site | part which opposes the cylinder parts 11b and 12b in the back surface of the leaf valves 10a and 10b contact | abuts to the cylinder parts 11b and 12b, since the bending of the leaf valves 10a and 10b is suppressed, the predetermined amount of the said bending is In this embodiment, when the piston speed reaches the high speed region, the leaf valves 10a, 10a, 10b can be adjusted by setting the gap length between the rear surfaces of the leaf valves 10a, 10b and the cylindrical portions 11b, 12b. The amount by which 10b bends is defined as a predetermined amount. That is, the piston speed, which is the starting point at which the bending of the leaf valves 10a and 10b is suppressed, is set to be the boundary between the medium speed and the high speed.

  In addition, since it should just be able to set to the value which aimed at the bending rigidity of each plate 11a, 12a, the thickness of each plate member p which comprises each plate 11a, 12a may be set to the same, and it sets to differ. May be.

  Next, the operation of the valve structure configured as described above will be described. First, when the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the pressure in the other chamber 42 increases, and the hydraulic oil in the other chamber 42 passes through the opening window 6a and the port 2a on the one side, Try to move into the chamber 41.

  When the piston speed, which is the expansion / contraction speed of the shock absorber, is in the low speed region, the hydraulic oil is notched by the notch provided on the outer periphery of the leaf valve 10a on the one side seated on the valve seat 1a or the valve seat 1a When passing through the formed orifice and the subsequent piston speed increases and reaches the middle speed region, the hydraulic oil deflects the outer periphery of the leaf valve 10a on one side, and the leaf valve 10a and valve seat 1a on the one side. Pass through the gap between.

  When the piston speed is in the low / medium speed region, the valve does not bend until the back surface of the leaf valve 10a on one side comes into contact with the cylindrical portion 11b of the valve stopper 11, and the deflection of the leaf valve 10a on the one side is not suppressed by the valve stopper 11. .

  Therefore, when the piston speed is in the low / medium speed region, the deflection of the leaf valve 10a on one side is not suppressed by the valve stopper 11, and in this low / medium speed region, the leaf valve on the one side fixed at the inner peripheral end is fixed. The damping characteristic (relationship of the damping force to the piston speed) on which only 10a acts will be exhibited. And by setting the bending rigidity of the leaf valve 10a on one side low, as shown by the solid line in FIG. 2, the inclination of the damping characteristic in the medium speed region is reduced as shown in the solid line in FIG. 2, and compared with the conventional valve structure. Thus, the generated damping force can be set to be low.

  On the other hand, when the speed of the piston 1 reaches the high speed region and the difference between the pressure in the other chamber 42 and the pressure in the one chamber 41 becomes large, the outer periphery of the leaf valve 10a on one side of the hydraulic oil is moved upward in FIG. So that the back surface of the leaf valve 10a on one side comes into contact with the cylindrical portion 11b of the valve stopper 11, and the plate 11a of the valve stopper 11 is bent together with the leaf valve 10a on one side. Become.

  That is, when the piston speed reaches the high speed region, the leaf valve 10a on one side is bent by the high bending rigidity synthesized by superimposing the bending rigidity of the plate 11a of the valve stopper 11 on its own bending rigidity. Further bending of the leaf valve 10a is suppressed.

  Therefore, when the piston speed is in the high speed region, the leaf valve 10a becomes difficult to bend due to the action of the valve stopper 11 as the piston speed increases, and the damping characteristic in this high speed region is as shown by the solid line in FIG. As the piston speed increases, the inclination increases, and the generated damping force when the piston speed is in the high speed region is increased.

  On the contrary, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the configuration of the valve structure arranged on the lower side of the piston 1 is mutually different from the configuration arranged on the upper side of the piston 1. Since the configuration is upside down, the same operation as described above is exhibited.

  Specifically, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the pressure in the one chamber 41 increases, and the hydraulic oil in the one chamber 41 passes through the opening window 6b and the port 2b on the other side. Then, it tries to move into the other chamber 42. When the piston speed, which is the expansion / contraction speed of the shock absorber, is in the low speed region, the hydraulic oil is notched by the notch provided on the outer periphery of the leaf valve 10b on the other side seated on the valve seat 1b or the valve seat 1b. It passes through the formed orifice.

  When the piston speed thereafter increases and reaches the middle speed region, the hydraulic oil bends the outer periphery of the leaf valve 10b on the other side and passes through the gap between the leaf valve 10b and the valve seat 1b. Since the back surface of the leaf valve 10b does not contact the cylindrical portion 12b of the valve stopper 12 and the bending of the leaf valve 10b on the other side is not suppressed, the leaf valve 10b on the other side fixed at the inner peripheral end in this low / medium speed region. The damping characteristic (relationship of the damping force with respect to the piston speed) on which only the pressure acts is exhibited. Then, by setting the bending rigidity of the leaf valve 10b on the other side low, as shown by the broken line in FIG. 2, the inclination of the damping characteristic in the region where the piston speed is medium is reduced, and compared with the conventional valve structure. Thus, the generated damping force can be set to be low.

  Further, when the speed of the piston 1 reaches the high speed region, the leaf valve 10b on the other side becomes difficult to bend due to the action of the valve stopper 12 as the piston speed increases, and the damping characteristic in the high speed region is shown in FIG. As shown by the broken line, the inclination increases as the piston speed increases, and the generated damping force when the piston speed is in the high speed region is increased.

  Therefore, in the valve structure of the shock absorber according to the present embodiment, the piston speed can be increased in the high speed region while the piston speed can be set low, while the piston speed can be set low. The damping force generated according to the piston speed is not excessive or deficient, and the riding comfort in the vehicle can be improved.

  Further, in this valve structure, the coil spring for urging the leaf valves 10a and 10b is not required, and the natural length of the coil spring is not increased, and the axial length of the piston portion including the valve structure is increased. Therefore, there is no problem that the stroke length, which is the extendable range of the shock absorber, is shortened, and the mountability to the vehicle is not deteriorated.

  Further, since the configuration in which the back surfaces of the leaf valves 10a and 10b are urged by coil springs is not adopted, there is no concern that variations in the urging force of the coil springs will cause variations in the damping characteristics of each product, and buffering is possible. The reliability and stability of the valve structure of the vessel is improved.

  Furthermore, as described above, in the valve structure according to the present embodiment, the above-described effects can be obtained with a simple configuration in which the valve stoppers 11 and 12 are stacked on the leaf valves 10a and 10b stacked on the piston 1 serving as a valve disk. And can be assembled very easily.

  By the way, the piston speed at which the damping force should be increased, that is, the boundary between the medium speed and the high speed, can be set to be optimal for a vehicle equipped with a shock absorber that embodies the valve structure. Since it can be implemented by adjusting the length of the gap between the back surface of the valves 10a, 10b and the cylindrical portions 11b, 12b of the valve stoppers 11, 12, it is simple. Specifically, the adjustment of the length of the gap between the back surfaces of the leaf valves 10a and 10b and the cylindrical portions 11b and 12b of the valve stoppers 11 and 12 is performed by adjusting the thickness and number of spacers 13 and 14, or This can be done by adjusting the length of the cylindrical portions 11b, 12b.

  Further, when the outer diameters of the tube portions 11b and 12b of the valve stoppers 11 and 12 are made smaller than the leaf valves 10a and 10b, bending at the portions supported by the tube portions 11b and 12b of the leaf valves 10a and 10b is suppressed. Therefore, the outer peripheral side of the supporting portions of the leaf valves 10a and 10b bends according to their own bending rigidity without overlapping the bending rigidity of the plates 11a and 12a.

  Therefore, the smaller the outer diameter of the cylindrical portions 11b and 12b, the longer the distance from the portion where the cylindrical portions 11b and 12b of the leaf valves 10a and 10b abut to the outer peripheral edge, and the outer periphery of the leaf valves 10a and 10b. Since the amount of bending increases, the damping coefficient in the high speed region tends to decrease as the outer diameter of the cylindrical portions 11b and 12b decreases.

  By adjusting the outer diameters of the cylinder portions 11b and 12b in this way, it becomes possible to adjust the damping characteristics after the leaf valves 10a and 10b contact the valve stoppers 11 and 12.

  In the above description, the valve structure of the present invention has been described using an example embodied in the damping valve on both sides of the pressure expansion of the piston portion of the shock absorber. However, only the expansion side or the pressure side damping valve is described. It can also be embodied in the base valve unit, and can be applied to a shock absorber valve that functions as a damping force generating element that generates a damping force. Of course. That is, when the valve structure is embodied in the base valve portion, one chamber may be one of the piston side chamber or the reservoir chamber, and the other chamber may be the other of the piston side chamber or the reservoir chamber.

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

It is a longitudinal cross-sectional view in a part of piston part of the shock absorber by which the valve structure of the shock absorber in one embodiment was embodied. It is a figure which shows the damping characteristic in the buffer which embodied the valve | bulb structure of the buffer of one Embodiment. It is a longitudinal cross-sectional view of the piston part of the buffer which actualized the valve structure of the conventional buffer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston 1a, 1b which is a valve disc Valve seat 2a One side port 2b Other side port 3a, 3b Window 5 Piston rod 5a Piston rod tip 5b Piston rod step 5c Piston rod screw groove 6a, 6b Opening window 10a Leaf valve 10b on one side Leaf valve 11, 12 on the other side Valve stopper 11a, 12a Plate 11b on valve stopper, 12b Cylindrical portion 13, 14 on valve stopper 15 Piston nut 40 Cylinder 41 One chamber 42 Other chamber p Plate member r ring

Claims (2)

In a valve structure of a shock absorber, comprising: a valve disk in which a port is formed; an annular leaf valve that is stacked on the valve disk to open and close the port; and a valve stopper that is stacked on the leaf valve and suppresses bending of the leaf valve. The stopper includes a plate that is elastically stacked on the leaf valve, and a cylindrical portion that protrudes from the plate toward the leaf valve and contacts the back surface of the leaf valve when the leaf valve is bent by a predetermined amount. Valve structure. The shock absorber valve structure according to claim 1, wherein the plate is formed by laminating a plurality of plate members.

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