JP2009063079A - Buffer valve structure - Google Patents

Abstract

To provide a valve structure of a shock absorber capable of improving riding comfort in a vehicle even when a piston speed reaches a high speed region.
SOLUTION: One channel 7 that communicates one chamber 41 and each port 2a, 2b, one channel 8 that communicates the other chamber 42 and each port 2a, 2b, and one channel One side throttle valve 11 provided with a valve body 12 provided in the middle of the passage 7 and capable of reducing the flow passage area, and provided in the middle of the other flow passage 8 can reduce the flow passage area. A throttle valve 13 provided with the valve body 14, a communication passage 15 that communicates the one chamber 41 and the other chamber 42, a pair of orifices 16 a and 17 a provided in series in the middle of the communication passage 15, The pressure between the orifices 16a and 17a is applied to the valve body 12 on the one side in the direction of reducing the flow path area in the direction of the communication passage 15 and the flow path area is reduced on the valve body 13 on the other side. The pressure between the orifices 16a and 17a in the middle of the communication path To use.
[Selection] Figure 1

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.

  Specifically, for example, as shown in FIG. 4, the valve structure of the shock absorber has a cylindrical shape that fixes the piston P to the piston rod R without fixedly supporting the inner peripheral side of the leaf valve L. A valve structure of a shock absorber is proposed in which the inner periphery of the leaf valve L is slidably contacted with the outer periphery of the piston nut N and the back surface of the leaf valve L is urged by the spring S via the main valve M. However, it is embodied in the expansion side damping valve of the shock absorber (see, for example, Patent Document 1).

In the shock absorber to which this valve structure is applied, 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 stacked on the leaf valve L. Since it bends with the contact part as a fulcrum, as shown in FIG. 5, it exhibits substantially the same damping characteristics as the valve structure in which the inner periphery is fixedly supported. The pressure of the hydraulic oil passing through the valve acts on the leaf valve L, and the leaf valve L lifts and retreats in the axial direction from the piston P together with the main valve M against the urging force of the spring S. Compared to the valve structure of the shock absorber supported by the vehicle, the flow path area is increased, and an excessive damping force can be suppressed to improve the riding comfort in the vehicle.
JP-A-9-291196 (FIG. 1)

  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.

  This is because, for example, when the piston speed when the piston P moves upward reaches the high speed region, in the conventional shock absorber valve structure, the leaf valve L moves backward from the piston P in the axial direction according to the piston speed. The damping coefficient does not increase.

  Therefore, when the piston speed reaches the high speed region, the damping force is insufficient, and the vibration is not sufficiently suppressed, so that the riding comfort in the vehicle is deteriorated.

  Therefore, the present invention was devised to improve the above problems, and the object of the present invention is to improve the riding comfort in the vehicle even when the piston speed reaches the high speed region. It is to provide a valve structure of a shock absorber.

  In order to solve the above-described object, the problem-solving means in the present invention includes a valve disk having a pair of ports that separate one chamber and the other chamber in the shock absorber and communicate the one chamber with the other chamber. A leaf valve on one side that is stacked on the side surface of the one chamber of the valve disc and opens and closes one port, and a leaf valve on the other side that is stacked on the side surface of the other chamber of the valve disc and opens and closes the other port. Provided in the middle of the one-side flow path communicating between the one chamber and each port, the other-side flow path communicating between the other chamber and each port, and the one-side flow path One side throttle valve provided with a valve body capable of reducing the flow area and the other side throttle provided with a valve body provided in the middle of the other side flow path and capable of reducing the flow area Communication between the valve and one chamber and the other chamber And a pair of orifices arranged in series in the middle of the communication path, and the pressure between the orifices is applied to the valve body on one side in the middle of the communication path in the direction of reducing the flow area. In addition, the pressure between the orifices is applied to the valve body on the other side in the middle of the communication path in the direction of reducing the flow path area.

  According to the valve structure of the shock absorber of the present invention, when the piston speed is in the medium speed region, the damping force is kept low, and when the piston speed reaches the high speed region, the piston speed is in the medium speed region. Further, the damping force can be increased, and even when the piston speed reaches the high speed region, the damping force is not insufficient, vibration is sufficiently suppressed, and the riding comfort in the vehicle can be improved.

  In addition, in a situation where the amplitude at which the shock absorber is fully extended is large and the piston speed reaches the high speed region, the damping force generated by the shock absorber can be increased. It is possible to reduce the impact at the time of maximum extension.

  Furthermore, since the secondary pressure, which is the pressure between each orifice, is introduced to the pressure chamber in the communication path, both the throttle valves can be operated only by installing a single communication path. Therefore, the processing is simplified and the manufacturing cost 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 spring urging force, and the valve structure of the shock absorber 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 an example of a damping characteristic in the shock absorber in which the valve structure of the shock absorber according to the embodiment is embodied. FIG. 3 is a diagram illustrating another example of a damping characteristic in the 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 provided with a pair of ports 2a and 2b which separate the chamber 42 and communicate with the one chamber 41 and the other chamber 42, and one port stacked on the side surface of the one chamber of the piston 1 A leaf valve 10a on one side that opens and closes the pressure port 2a, a leaf valve 10b on the other side that opens and closes the expansion port 2b that is stacked on the other chamber side surface of the piston 1, and one chamber 41 and each port 2a. , 2b communicating with one side flow path 7, the other chamber 42 communicating with each port 2a, 2b, the other side flow path 8 and the one side flow path 7 in the middle of the flow path area. Valve that can be reduced The throttle valve 11 on one side provided with 12, the throttle valve 13 on the other side provided with a valve body 14 provided in the middle of the flow path 8 on the other side and capable of reducing the flow area, the one chamber and the other A communication passage 15 communicating with the chamber, a pair of orifices 16a and 17a provided in series in the middle of the communication passage 15, and a pressure between the orifices 16a and 17a in the middle of the communication passage 15 is guided. The pressure between the orifices 16a and 17a in the middle of the communication passage 15 and the pressure chamber 18 on the one side energizing the valve body 12 in the throttle valve 11 on the one side in the direction of reducing the flow passage area with the pressure. And a pressure chamber 19 on the other side for energizing the valve body 14 of the throttle valve 13 on the other side in a direction to reduce the flow path area with the pressure.

  In this document, in order to facilitate the description of each part, the member disposed on the one chamber 41 side with the piston 1 as a boundary is referred to as one member, and the member disposed on the other chamber 42 side is the other. As side members, members having the same name are distinguished.

  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 that slidably passes through a head member (not shown), a piston 1 that is inserted into the tip 5a of the piston rod 5 that forms a shaft member, and is fixed to the tip 5a, and a cylinder 40 An upper chamber 41 in FIG. 1, a lower chamber 42 in the lower side in FIG. 1, a sealing member (not shown) that seals the lower end of the cylinder 40, and the cylinder 40 protrude from the cylinder 40. A cylinder or an air chamber (not shown) that compensates for a change in the cylinder volume corresponding to the volume of the piston rod 5 is provided, 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 passes 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 disk is formed in an annular shape, and allows the hydraulic oil to pass from the other chamber 42 to the first chamber 41. An extension port 2b that allows passage from one chamber 41 to the other chamber 41, windows 3a and 3b that are respectively connected to the outlet ends of the ports 2a and 2b, and windows 3a and 3b that are outlet ends of the ports 2a and 2b And annular valve seats 1a and 1b formed on the outer peripheral side.

  Further, in this embodiment, the open ends of the ports 2a and 2b are arranged on the outer peripheral side of the windows 3a and 3b so as not to be blocked by the leaf valves 10a and 10b stacked on the piston 1, respectively. . The pressure port 2a is not closed by the leaf valve 10b on the other side, and the expansion port 2b is not limited to the one shown in the drawing for the arrangement and shape unless it is closed by the leaf valve 10a on the one side. For example, you may employ | adopt the structure which arrange | positions each port 2a, 2b on the same periphery, and makes valve seat 1a, 1b what is called a petal type.

  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. 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. Yes.

  The piston rod 5 further includes a vertical hole 15a that opens from the lower end of the tip 5a, and a horizontal hole 15b that opens from a side portion above the step portion 5b of the piston rod 5 and communicates with the vertical hole 15a. The vertical hole 15a and the horizontal hole 15b form a communication path 15 that connects the one chamber 41 and the other chamber 42.

  Further, plugs 17 and 17 having an orifice 17a are screwed to the lower side of the vertical hole 15a in FIG. 1, and plugs 16 and 16 having an orifice 16a are screwed to the lateral hole 15b. During the expansion stroke of the shock absorber, the hydraulic oil passes through the communication path 15 as well as the expansion port 2b and moves from the one chamber 41 to the other chamber 42, and during the compression stroke of the shock absorber, the hydraulic fluid is Since not only the pressure port 2a but also the communication passage 15 passes through and moves from the other chamber 42 to the one chamber 41, the orifices 16a and 17a are arranged in series in the communication passage 15. The pressure between the orifices 16 a and 17 a in the communication path 15 takes a value between the pressure in the one chamber 41 and the pressure in the other chamber 42. In the figure, two orifices 16a and 17a are provided. However, the number of the orifices 16a and 17a is arbitrary, and the number of the orifices 16a and 17a is arbitrary in the communication path 15 between the orifices 16a and 17a. The pressure can be arbitrarily changed depending on the number of the orifices 16a and 17a installed. As described above, in the present embodiment, the plugs 16 and 17 having the orifices 16a and 17a are provided in the middle of the communication path 15, so that the change in the number of orifices is very simple. 15, the pressure between the orifices 16 a and 17 a can be easily set. However, the above setting may be performed by changing the diameters of the orifices 16 a and 17 a. That is, the orifice diameter may be different depending on the plug. In addition, the orifices 16a and 17a may be configured as long as the diameter of the communication path 15 is partially reduced and can be provided directly in the communication path 15.

  Returning, leaf valve 10a, 10b laminated | stacked up and down in FIG. 1 of the piston 1 is comprised as a lamination | stacking leaf valve by laminating | stacking several sheets formed in cyclic | annular form, The leaf valve 10a of one side is A valve seat 1a formed on the one chamber 41 side of the piston 1 is brought into contact with the outlet end of the pressure port 2a, and the leaf valve 10b on the other side is formed on the side of the other chamber 42 of the piston 1. The outlet end of the extension port 2b is closed. 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 the damping force to the piston speed) realized by this valve structure. It may be optional, and there may be a single sheet or multiple sheets 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. it can.

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

  Subsequently, a spacer 21, a partition member 22, a cylindrical holding member 23, and a stopper 24 are stacked above the leaf valve 10a on one side in FIG. Further, a cylindrical valve body 12 in the throttle valve 11 on one side is slidably mounted on the outer periphery of the holding member 23 above the partition member 22 in FIG. 1 is urged upward in FIG. 1 by a spring 25 interposed between the valve member 12 and the partition member 22, and the upper end thereof abuts against the stopper 24 to restrict further upward movement of the valve body 12.

  On the other hand, a spacer 26, a partition member 27, and a holding member 28 are laminated below the leaf valve 10b on the other side in FIG. 1, and further on the throttle valve 13 on the other side below the partition member 28 in FIG. A cylindrical valve body 14 is slidably mounted on the outer periphery of the holding member 28, and the valve body 14 is moved downward in FIG. 1 by a spring 29 interposed between the valve body 14 and the partition member 27. The upper end of the valve body 14 abuts on a piston nut 30 screwed into a screw groove 5c formed at the tip 5a of the piston rod 5, and the further upward movement of the valve body 14 is restricted.

  And the stopper 24, the holding member 23, the valve body 12, the spring 25, the partition member 22, the spacer 21, the leaf valve 10b on the other side, the piston 1, the leaf valve 10a on the one side, the spacer 26, the partition member 27, the holding These members of the member 28, the spring 29, and the valve body 14 are sequentially assembled to the tip 5a of the piston rod 5, and the piston nut 30 and the stepped portion of the piston rod 5 screwed into the screw groove 5c provided in the tip 5a. 5b and is fixed to the piston rod 5.

  That is, in this valve structure, the configuration of the spacer 21, the partition member 22, the holding member 23, the valve body 12 disposed in the one chamber 41 on the upper side of the piston 1, and the inside of the other chamber 42 on the lower side. The configuration of the spacer 26, the partition member 27, the holding member 28, and the valve body 14 that are arranged in the above is in a line-symmetric relationship with the piston 1 as a boundary and upside down.

  The partition member 22 disposed above the piston 1 in FIG. 1 has a bottom portion 22a and a cylindrical portion 22b and is formed into a bottomed cylindrical shape, and the piston is configured so that the cylindrical portion 22b is fitted to the outer periphery of the piston 1. 1 and the chamber R1 is partitioned from the one chamber 41 with the piston 1. Further, the bottom 22a of the partition member 22 has a hole 22c into which the tip 5a of the piston rod 5 can be inserted, a plurality of through holes 22d provided on the same circumference and penetrating the bottom 22a, and the same circumference. A plurality of through holes 22e that pass through the bottom portion 22a and are arranged on the inner peripheral side of the through hole 22d, an annular valve seat 22f provided between the through hole 22d and the through hole 22e, and an annular valve seat 22f is provided with an annular inclined surface 22g provided on the outer periphery, and the one-side flow path 7 is branched into the main flow path 7a and the sub-flow path 7b through the through-hole 22d and the through-hole 22e. The main flow path 7a and the sub flow path 7b that constitute the above-described structure communicate the one chamber 41 with the ports 2a and 2b through the room R1.

  On the other hand, the partition member 27 disposed below the piston 1 in FIG. 1 is similarly provided with a bottom portion 27a and a cylindrical portion 27b so as to have a bottomed cylindrical shape, and the cylindrical portion 27b is fitted to the outer periphery of the piston 1. The chamber R2 is separated from the other chamber 42 between the piston 1 and the piston 1. Further, the bottom 27a of the partition member 27 has a hole 27c into which the tip 5a of the piston rod 5 can be inserted, a plurality of through holes 27d provided on the same circumference and penetrating the bottom 27a, and the same circumference. A plurality of through holes 27e disposed through the bottom 27a and disposed on the inner peripheral side of the through hole 27d, an annular valve seat 27f provided between the through hole 27d and the through hole 227e, and an annular valve seat 27f is provided with an annular inclined surface 27g provided on the outer periphery from 27f, and the other flow path 8 is branched into the main flow path 8a and the sub flow path 8b by the through hole 27d and the through hole 27e. These other main channels 8a and sub-channels 8b communicate the other chamber 42 with the ports 2a and 2b through the room R2.

  Subsequently, as shown in FIG. 1, the holding member 23 is formed in a cylindrical shape with a small diameter portion 23a on the lower side in FIG. 1 and a large diameter portion 23b on the upper side in FIG. Is provided with an annular groove 23c, and is provided with a passage 23d communicating the annular groove 23c and the small diameter portion 23a. The holding member 23 is laminated on the partition member 22 and fixed to the tip 5a of the piston rod 5 so that it cannot move in the axial direction with respect to the piston 1. It opposes the through-hole 15c branched from between the orifices 16a and 17a.

  Further, the valve body 12 includes an inner cylinder 12a, an inner peripheral flange 12b connected to the inner periphery of the lower end of the inner cylinder 12a in FIG. 1, an outer peripheral flange 12c connected to the outer periphery of the upper end of the inner cylinder 12a in FIG. A valve cylinder 12d suspended from the outer periphery and a groove 12e provided at the upper end in FIG. 1 are configured. The inner periphery of the inner peripheral flange 12b is connected to the outer periphery of the small-diameter portion 23a of the holding member 23. The inner periphery is slidably attached to the outer periphery of the holding member 23 such that the inner periphery is brought into sliding contact with the outer periphery of the large-diameter portion 23 b of the holding member 23. Further, the valve body 12 separates the pressure chamber 18 on one side by the outer periphery of the small diameter portion 23a of the holding member 23 and the lower end in FIG. 1 of the large diameter portion 23b and the inner periphery and the inner peripheral flange 12b of the valve body 12, The pressure chamber 18 is communicated between the orifices 16 a and 17 a of the communication hole 15 through a passage 23 d provided in the holding member 23, an annular groove 23 c and a through hole 15 c provided in the piston rod 5. The pressure between the orifices 16a and 17a of the communication hole 15 (hereinafter simply referred to as “secondary pressure”) is guided.

  Further, the spring 25 interposed between the valve body 12 and the partition member 22 is urged upward in FIG. 1 and is regulated by the stopper 24 in the state where no other force is applied. Placed in. That is, the valve body 12 is disposed in the one chamber 41, and the pressure in the one chamber 41 acting as the pressure receiving area of the inner cylinder 12a, the outer peripheral flange 12c and the valve cylinder 12d in FIG. The area, that is, the area of the upper surface of the inner peripheral flange 12b in FIG. 1 is urged downward by the pressure of the pressure chamber 18 acting as a pressure receiving area, and conversely, the inner cylinder 12a, the inner peripheral flange 12b, the outer peripheral flange 12c and the valve cylinder 1d is biased upward by the pressure of the one chamber 41 acting as the pressure receiving area and the spring force of the spring 25.

  The groove 12e provided in the valve body 12 guides the pressure in the one chamber 41 through the groove 12e to the contact portion even when the valve body 12 is in close contact with the stopper 24. FIG. The pressure in the one chamber 41 can be applied to the entire middle upper surface.

  The throttle valve 11 on one side includes a valve body 12, a spring 25, and an annular valve seat 22 f provided on the partition member 22, and the valve body 12 resists the urging force of the spring 25. 1 moves downward in FIG. 1, the valve cylinder 12d approaches the annular valve seat 22f provided on the partition member 22 so as to reduce the flow passage area in the sub flow passage 7b. When the lower end of 12d in FIG. 1 is seated on the annular valve seat 22f, the communication between the one chamber 41 and the room R1 by the sub-channel 7b is blocked, and the channel area of the channel 7 on the one side is reduced to the main channel area. The flow path 7a is reduced to the flow path area.

  That is, the differential pressure between the secondary pressure in the communication passage 15 and the pressure in the one chamber 41 acts on the valve body 12 downward in FIG. 1 in the direction of reducing the flow path area, and the differential pressure increases. The valve body 12 moves downward in FIG. 1 against the spring force of the spring 25 and operates to reduce the flow area of the flow path 7 on one side. In this embodiment, the pressure chamber 18 is provided to realize the secondary pressure of the communication passage 15 described above on the valve body 12.

  Specifically, during the compression stroke of the shock absorber in which the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the valve body 12 of the throttle valve 11 on one side acts as a pressure receiving area using the cross-sectional area of the pressure chamber 18. 1 which is generated by the differential pressure between the secondary pressure which is high in the communication passage 15 guided to the pressure chamber 18 and the pressure in the one chamber 41 which is low, and the spring 25 which is upward in FIG. Thrust acts. And when the thrust by the said differential pressure exceeds the thrust by the spring 25, the valve body 12 in the throttle valve 11 on one side is moved downward in FIG. 1 on the partition member 22 side and approaches the partition member 22. Thus, the flow passage area of the sub flow passage 7b communicating with the through hole 22e is narrowed to reduce the flow passage area of the flow passage 7 on one side.

  In other words, when the secondary pressure in the communication passage 15 exceeds the pressure in the one chamber 41 by a predetermined amount, the valve body 12 moves downward in FIG. In the case of this embodiment, finally, the sub-channel 7b is cut off, and the one chamber 41 and each port 2a, 2b are merely communicated with only the main channel 7a.

  When the secondary pressure in the communication passage 15 exceeds the pressure in the one chamber 41 by a predetermined amount, the valve body 12 starts to throttle the sub-channel 7b. The predetermined amount is set by the pressure in the one chamber 41 and the secondary pressure. It can be arbitrarily set by adjusting the cross-sectional area of the pressure chamber 18 serving as a pressure receiving area where the pressure acts, the spring constant of the spring 25, the number of orifices 16a and 17a for adjusting the secondary pressure, and the orifice diameter. In this case, the piston speed of the shock absorber is set at the boundary between medium speed and high speed.

  Furthermore, in the case of this embodiment, during the expansion stroke of the shock absorber in which the piston 1 moves upward in FIG. The pressure of the sub flow path 7b on the port 2a, 2b side is depressurized from the valve body 12 by giving resistance to the flow of hydraulic oil passing through 7b, and the piston speed exceeds the high speed region and reaches the high speed region. The flow rate of the hydraulic fluid flowing through the sub flow path 7b becomes very high, and the pressure in the sub flow path 7b on the port 2a, 2b side is greatly reduced from the valve body 12, and the one chamber 41 and the pressure are reduced. The differential pressure between the pressures in the sub flow path 7b increases, and the thrust force that presses the valve body 12 downward in FIG. 1 increases, and the valve body 12 squeezes the sub flow path 7b against the urging force of the spring 25. Set to reduce the flow area It has been.

  That is, the throttle valve 11 on one side operates to throttle the sub-channel 7b when the piston speed reaches the high speed region when the shock absorber is in the compression stroke, and the piston speed is high even when the shock absorber is in the expansion stroke. When reaching the speed region, the sub-channel 7b is operated to be throttled.

  In the case of this embodiment, the throttle valve 11 on one side closes the sub-channel 7b in the channel 7 on the one side. Although it is advantageous in that the final channel area can be set by the main channel 7a, a single channel can be throttled by the throttle valve 11 on one side without branching the channel 7 on one side. It may be. When narrowing a single flow path, if the flow path is completely blocked, the communication between the one chamber 41 and the other chamber 42 is cut off, so that the flow path may not be completely blocked.

  Further, the valve body 12 is in the uppermost position and comes into contact with the stopper 24 to contact the annular valve seat 22f from the position where the flow passage area of the flow passage 7 on one side is maximized. The area of the annular gap between the partition member 22 and the valve body 12, that is, the flow path area of the sub flow path 7 b gradually decreases in accordance with the displacement amount of the valve body 12 until it is displaced to the position where the area is minimized. It has become. That is, the valve body 12 is at the time of the compression stroke of the shock absorber, the secondary pressure exceeds the pressure of the one chamber 41 by a predetermined amount and the pressure difference becomes larger, and at the time of the expansion stroke of the shock absorber, As the degree of depressurization of the sub-channel 7b increases, the sub-channel 7b functions closer to the annular inclined surface 22g of the partition member 22 so that the channel 7 on one side is largely narrowed.

  In the valve structure in this embodiment, the partition area is gradually reduced in accordance with the increase in the pressure difference between the secondary pressure and the pressure in the one chamber 41 and the degree of decompression of the sub-channel 7b. A mortar-shaped annular inclined surface 22g is formed on the outer peripheral side of the annular valve seat 22f on which the valve body 12 of the member 22 is seated, and the area between the partition member 22 and the valve body 12 is minimized. This is an annular gap formed between the annular inclined surface 22 g of the member 22 and the outer periphery of the lower end of the valve cylinder 12 d of the valve body 12.

  That is, in the valve structure according to the present embodiment, the area of the annular gap formed between the annular inclined surface 22g and the outer periphery of the lower end of the valve cylinder 12d of the valve body 12 is minimized, and the annular inclined surface 22g and the valve cylinder are minimized. The flow path area reduction gain with respect to the displacement amount of the valve body 12 in the area of the annular gap formed between the lower end outer periphery of 12d (the ratio of the flow area reduction with respect to the displacement amount of the valve body 12) is determined by the annular inclined surface 22g. In the absence, the pressure is reduced compared to the channel area reduction gain in the area of the annular gap formed between the annular valve seat 22f and the lower end surface of the valve cylinder 12d. The channel area can be gradually reduced according to the increase in the pressure difference and the degree of pressure reduction of the sub-channel 7b.

  In this manner, in order to gradually reduce the flow area of the one-side flow path 7 in accordance with the increase in the pressure difference between the pressure in the one chamber 41 and the secondary pressure and the degree of pressure reduction in the sub flow path 7b. Although not shown, an annular inclined surface having a truncated cone shape may be provided on the inner peripheral side of the annular valve seat 22f, or the annular valve seat 22f itself may be provided on the inner peripheral side or the outer peripheral side of the partition member 22. It may be an annular inclined surface that is inclined.

  In turn, as shown in FIG. 1, the holding member 28 has the same configuration as the holding member 23 described above, and includes a small diameter portion 28a on the upper side in FIG. 1 and a large diameter portion 28b on the lower side in FIG. The annular groove 28c is provided on the inner peripheral side, and a passage 28d that communicates the annular groove 28c and the small diameter portion 28a is provided. The holding member 28 is laminated below the partition member 27 and fixed to the tip 5a of the piston rod 5 so that it cannot move in the axial direction with respect to the piston 1, and the annular groove 28c is formed in the communication hole 15. These are opposed to a through hole 15d branched from between each of the orifices 16a and 17a.

  Further, the valve body 14 includes an inner cylinder 14a, an inner peripheral flange 14b connected to the inner periphery of the upper end of the inner cylinder 14a in FIG. 1, an outer peripheral flange 14c connected to the outer periphery of the lower end of the inner cylinder 14a in FIG. 1 and a groove 14e provided at the lower end in FIG. 1. The inner periphery of the inner peripheral flange 14b is set to the outer periphery of the small diameter portion 28a of the holding member 28, and the inner periphery of the inner cylinder 14a is set. The holding member 28 is slidably mounted on the outer periphery of the holding member 28 in sliding contact with the outer periphery of the large-diameter portion 28b. Further, the valve body 14 defines a pressure chamber 19 on one side by the outer periphery of the small diameter portion 28a of the holding member 28 and the upper end of the large diameter portion 28b in FIG. 1 and the inner periphery and inner peripheral flange 14b of the valve body 14, The pressure chamber 19 is communicated between the orifices 16 a and 17 a of the communication hole 15 through a passage 28 d provided in the holding member 28, an annular groove 28 c and a through hole 15 d provided in the piston rod 5. A secondary pressure that is a pressure between the orifices 16a and 17a of the communication hole 15 is introduced.

  Further, a spring 29 interposed between the valve body 14 and the partition member 27 is urged downward in FIG. 1 and is regulated by the piston nut 30 in the state where no other force acts. Arranged above. That is, the valve body 14 is disposed in the other chamber 42, and the pressure in the other chamber 42 acting as the pressure receiving area of the inner cylinder 14 a, the outer peripheral flange 14 c and the valve cylinder 14 d in FIG. The area, that is, the area of the inner peripheral flange 14b in FIG. 1 is biased downward by the pressure of the pressure chamber 19 acting as a pressure receiving area, and conversely, the inner cylinder 14a, the inner peripheral flange 14b, the outer peripheral flange 14c and the valve cylinder 14d is urged downward by the pressure of the other chamber 42 acting as the pressure receiving area and the spring force of the spring 29.

  The groove 14e provided in the valve body 14 guides the pressure in the other chamber 42 to the contact portion via the groove 14e even when the valve body 14 is in close contact with the piston nut 30. The pressure in the other chamber 42 can be applied to the entire lower surface of 1.

  The throttle valve 13 on the other side includes a valve body 14, a spring 29, and an annular valve seat 27 f provided on the partition member 27. The valve body 14 resists the urging force of the spring 29. 1 moves upward in FIG. 1, the valve cylinder 14d approaches the annular valve seat 27f provided in the partition member 27 so as to reduce the flow path area in the sub flow path 8b. When the upper end of 14d in FIG. 1 is seated on the annular valve seat 27f, the communication between the other chamber 42 and the room R2 by the sub-channel 8b is cut off, and the channel area of the channel 8 on the other side is reduced to the main channel 14b. The channel area is reduced to the channel area of the channel 8a.

  That is, the throttle valve 13 on the other side has the same configuration as that of the throttle valve 11 on the one side except that the valve element 14 is disposed in the other chamber 42, and during the expansion stroke of the shock absorber. When the piston speed reaches the high speed region, the secondary pressure in the communication passage 15 exceeds the pressure in the other chamber 42 by a predetermined amount, and the valve body 14 moves upward in FIG. Eventually, the sub flow path 8b is shut off, and during the compression stroke of the shock absorber, the pressure on the ports 2a, 2b side is reduced from the valve body 14 of the sub flow path 8b, and the piston speed reaches the highest speed region. Then, the valve body 14 moves upward in FIG. 1 and operates so as to throttle the sub flow path 8b.

  In other words, during the expansion stroke of the shock absorber, the valve body 14 acts upward in FIG. 1 in which the differential pressure between the secondary pressure of the communication passage 15 and the pressure of the other chamber 42 decreases the flow path area. When the differential pressure increases, the valve element 14 moves upward in FIG. 1 against the spring force of the spring 29 and operates to reduce the flow area of the flow path 8 on the other side. During the compression stroke, resistance is applied to the flow of the hydraulic oil passing through the throttle valve 13 on the other side to depressurize the sub flow path 8b in the flow path 8 on the other side, and the other chamber 42 and the depressurized sub flow path 8b. 1 increases, the thrust for pressing the valve body 14 upward in FIG. 1 increases, and the valve body 14 squeezes the sub flow path 8b against the urging force of the spring 29 to reduce the flow path area. Works like this. In the case of this embodiment, in order to apply the differential pressure to the valve body 14, a pressure chamber 19 is provided to realize this.

  Also, in the case of the throttle valve 13 on the other side, since the partition member 27 is provided with the annular inclined surface 27g, the channel area reduction gain with respect to the displacement amount of the valve body 14 is reduced, and the other side channel 8 The channel area can be gradually reduced in accordance with the increase in the pressure difference between the pressure in the other chamber 42 and the secondary pressure and the degree of pressure reduction in the sub-channel 8b.

  In addition, in the throttle valve 13 on the other side, as in the case of the throttle valve 11 on the one side described above, an annular inclined surface in the shape of a truncated cone may be provided on the inner peripheral side of the annular valve seat 27f. The annular valve seat 27f itself may be an annular inclined surface that is inclined toward the inner peripheral side or the outer peripheral side of the partition member 27. Furthermore, the single channel may be throttled by the other throttle valve without branching the other channel 8 into the main channel 8a and the sub channel 8b.

  When the secondary pressure or the like in the communication passage 15 exceeds the pressure in the direction chamber 42 by a predetermined amount, the valve body 14 starts to throttle the sub flow path 8b. It can be arbitrarily set by adjusting the cross-sectional area of the pressure chamber 19 serving as a pressure receiving area where the secondary pressure acts, the spring constant of the spring 29, the number of orifices 16a and 17a for adjusting the secondary pressure, and the orifice diameter. However, in this case, the piston speed of the shock absorber is set at the boundary between the medium speed and the high speed. Further, as a matter of course, a predetermined amount at which the pressure in the one chamber 41, which serves as a reference when the throttle valve 11 on one side starts to throttle the flow path 7 on the one side during the expansion stroke of the buffer, should exceed the secondary pressure, The pressure in the other chamber 42, which serves as a reference for the other side throttle valve 13 to start to throttle the other side flow path 8 during the compression stroke, may be different from the predetermined amount that should exceed the secondary pressure.

  Further, in the configuration of the throttle valves 11 and 13, the valve bodies 12 and 14 are cylindrical and are mounted on the cylindrical holding members 23 and 28, respectively, so that the valve bodies 12 and 14 are attached to the holding members 23 and 28. Guided operation is ensured and the formation of the pressure chambers 18 and 19 is simplified and the assembly of the valve is facilitated. The shape and configuration of the valve bodies 12 and 14 are respectively on one side. It is natural that the design can be changed so as to be suitable for the flow path 7 and the flow path 8 on the other side.

  Next, the operation of the valve structure configured as described above will be described. First, when the shock absorber is in the extension stroke and the piston 1 moves upward in FIG. 15 and 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 formed by stamping the notch provided on the outer periphery of the leaf valve 10b seated on the valve seat 1b or the valve seat 1b. When passing through the communication passage 15 having the orifice and the orifices 16a and 17a, and then the piston speed increases and reaches the middle speed region, the hydraulic oil deflects the outer periphery of the leaf valve 10b, and the leaf valve 10b and the valve It also passes through the gap between the seat 1b. The secondary pressure between the orifices 16a and 17a in the communication passage 15 is a high pressure in the one chamber 41 and a low pressure in the other chamber 42 due to pressure loss caused when the hydraulic oil passes through the orifices 16a and 17a. Take the value between.

  When the piston speed is in the low / medium speed region, the predetermined amount is set so that the secondary pressure in the communication passage 15 does not exceed the pressure in the other chamber 42 by a predetermined amount. 1 is in the middle speed region, the valve body 14 of the throttle valve 13 on the other side cannot move upward in FIG. 1 against the urging force of the spring 29, and the throttle valve 13 on the other side cannot move on the other side. The flow area is not reduced by narrowing the flow path 8.

  Further, when the piston speed is in the low / medium speed region, the amount of pressure reduction in the sub flow path 7b due to the pressure loss when the hydraulic oil passes through the throttle valve 11 on one side is small, and the valve body 12 is caused by the urging force of the spring 25. In contrast, it cannot move downward in FIG. 1, and even in the throttle valve 11 on one side, the flow path area on the one side is restricted to reduce the flow area.

  Therefore, when the piston speed is in the low / medium speed region, damping characteristics (relationship of the damping force to the piston speed) by the leaf valve 10b on the other side and the orifices 16a and 17a of the communication path 15 are exhibited. Then, by setting the spring rigidity of the leaf valve 10b low, as shown in FIG. 2, the piston speed can be set so that the slope of the damping characteristic in the medium speed region is reduced and the damping force is lowered. .

  On the other hand, the speed of the piston 1 reaches the high speed region, the difference between the pressure in the one chamber 41 and the pressure in the other chamber 42 increases, and the secondary pressure in the communication passage 15 controls the pressure in the other chamber 42. When the amount exceeds the fixed amount, the thrust for pressing the valve body 14 upward in FIG. 1 exceeds the thrust of the spring 29, and the valve body 14 is pushed upward in FIG. The channel area of the channel 8 is reduced. The throttle valve 11 on one side does not reduce the flow area of the flow path 7 on the one side because the piston speed has not yet reached the high speed region.

  Then, when the difference between the secondary pressure in the communication passage 15 and the pressure in the other chamber 42 further increases after the piston speed reaches the high speed region, the valve body 14 changes the flow passage area to the pressure difference. Accordingly, the sub-flow path 8b is closed by contacting the annular valve seat 27f of the partition member 27 and finally disconnecting the one chamber 41 and the other chamber 42 through the through hole 27e. The one chamber 41 and the other chamber 42 are communicated with each other only by the channel 8a, and the channel area of the channel 8 on the other side is minimized.

  Therefore, when the speed of the piston 1 is in the high speed region, the flow area of the flow path 8 on the other side is gradually reduced as the pressure difference between the secondary pressure in the communication path 15 and the pressure in the other chamber 42 increases. As the speed of the piston 1 increases, the pressure loss gradually increases.

  That is, as shown in FIG. 2, the damping area is gradually limited when the piston speed reaches the high speed region and the throttle valve 13 of the other side throttles the other side of the flow path 8 for the first time. Therefore, the inclination becomes larger than that in the middle speed region, the damping force increases as the speed of the piston 1 increases, and the throttle valve 13 on the other side minimizes the flow passage area of the flow passage 8 on the other side. As the piston speed increases later, the slope of the damping characteristic decreases again, but the damping force increases as the flow path area decreases.

  Further, when the speed of the piston 1 reaches the highest speed region, the difference between the pressure in the one chamber 41 and the pressure in the other chamber 42 is further increased, and the flow rate of the hydraulic oil passing through the throttle valve 11 on one side is increased. When the pressure loss caused by the throttle valve 11 becomes large, the sub flow path 7b is greatly depressurized, and the thrust that presses the valve body 12 downward increases to move downward in FIG. The valve 11 reduces the flow area by narrowing the sub flow path 7b in the flow path 7 on one side.

  Then, when the piston speed further increases after the piston speed reaches the highest speed region, the valve body 12 in the throttle valve 11 on one side has a flow path area corresponding to the degree of pressure reduction of the sub flow path 7b. The sub-flow path 7b is closed by finally abutting the annular valve seat 22f of the partition member 22 and closing the communication between the one chamber 41 and the other chamber 42 through the through hole 22e. The one chamber 41 and the other chamber 42 are communicated with each other only by 7a to minimize the flow area of the flow path 7 on one side.

  That is, as shown in FIG. 2, the damping area is gradually limited as the damping characteristic during the first time the throttle valve 11 of the one side restricts the first flow passage 7 after the piston speed reaches the highest speed region. Therefore, the inclination becomes larger than that in the high speed region, the damping force increases as the speed of the piston 1 increases, and the throttle valve 11 on one side minimizes the flow area of the flow path 7 on the one side. As the piston speed increases later, the slope of the damping characteristic decreases again, but the damping force increases as the flow path area decreases.

  On the contrary, when the shock absorber is in the compression stroke and the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the configuration of the valve structure arranged on the upper side of the piston 1 is the lower side of the piston 1. Since the configuration arranged in the above is a configuration that is upside down, the same operation as described above is exhibited.

  Specifically, when the shock absorber is in the compression stroke and 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 flows into the pressure port 2 a and the communication port. It tries to move into the one chamber 41 through the passage 15.

  When the piston speed, which is the expansion / contraction speed of the shock absorber, is in the low speed region, the hydraulic oil is formed by stamping the notch provided on the outer periphery of the leaf valve 10a seated on the valve seat 1a or the valve seat 1a. When passing through the communication passage 15 having the orifice and the orifices 16a and 17a, and then the piston speed increases and reaches the middle speed region, the hydraulic oil deflects the outer periphery of the leaf valve 10a, and the leaf valve 10a and the valve It also passes through the gap between the seat 1a. The secondary pressure between the orifices 16a and 17a in the communication passage 15 is the difference between the pressure in the other chamber 42 which is high and the pressure in the low one chamber 41 due to the pressure loss caused when the hydraulic oil passes through the orifices 16a and 17a. Take the value between.

  When the piston speed is in the low / medium speed region, the predetermined amount is set so that the secondary pressure in the communication passage 15 does not exceed the pressure in the one chamber 41 by a predetermined amount. 1 is in the middle speed region, the valve body 12 in the throttle valve 11 on one side cannot move downward in FIG. 1 against the urging force of the spring 25, and the throttle valve 11 on one side does not move on the one side. The flow path area is not reduced by narrowing the flow path 7.

  Further, when the piston speed is in the low / medium speed region, the pressure reduction amount of the sub flow path 8b due to the pressure loss when the hydraulic oil passes through the throttle valve 13 on the other side is small, and the valve body 14 is caused by the urging force of the spring 29. Accordingly, it cannot move upward in FIG. 1, and even in the throttle valve 13 on the other side, the flow path area on the other side is restricted to reduce the flow area.

  Therefore, when the piston speed is in the low / medium speed region, damping characteristics are exhibited by the leaf valve 10a on one side and the orifices 16a and 17a of the communication passage 15. By setting the spring stiffness of the leaf valve 10a low, as shown in FIG. 2, the piston speed can be set so that the slope of the damping characteristic in the medium speed region is reduced and the damping force is lowered. .

  On the other hand, 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 increases, and the secondary pressure in the communication passage 15 determines the pressure in the one chamber 41. When the amount exceeds the fixed amount, the thrust for pushing the valve body 12 downward in FIG. 1 exceeds the thrust of the spring 25, and the valve body 12 is pushed downward in FIG. The flow channel area of the flow channel 7 is reduced. The throttle valve 13 on the other side does not reduce the flow area of the flow path 8 on the other side because the piston speed has not yet reached the high speed region.

  Then, when the difference between the secondary pressure in the communication passage 15 and the pressure in the one chamber 41 further increases after the piston speed reaches the high speed region, the valve body 12 changes the flow passage area to the pressure difference. Accordingly, the sub-flow path 7b is closed by contacting the annular valve seat 22f of the partitioning member 22 and finally disconnecting the one chamber 41 and the other chamber 42 through the through hole 22e. The one chamber 41 and the other chamber 42 are communicated with each other only by the channel 7a, and the channel area of the channel 7 on one side is minimized.

  Therefore, when the speed of the piston 1 is in the high speed region, the flow passage area of the flow passage 7 on one side is gradually reduced as the pressure difference between the secondary pressure in the communication passage 15 and the pressure in the one chamber 41 increases. The pressure loss gradually increases as the speed of the piston 1 increases.

  That is, as shown in FIG. 2, the damping area is gradually limited when the piston speed reaches the high speed region and the throttle valve 11 on the one side stops the throttle for the first time. Therefore, the inclination becomes larger than that in the middle speed region, the damping force increases as the speed of the piston 1 increases, and the throttle valve 11 on one side minimizes the flow area of the flow path 7 on the one side. As the piston speed increases later, the slope of the damping characteristic decreases again, but the generated damping force increases as the flow path area decreases.

  Further, when the speed of the piston 1 reaches the highest speed region, the difference between the pressure in the other chamber 42 and the pressure in the one chamber 41 is further increased, and the flow rate of the hydraulic oil passing through the throttle valve 13 on the other side is increased. When the pressure loss caused by the throttle valve 13 becomes large, the sub flow path 8b is greatly depressurized, the thrust that presses the valve body 14 upward increases, and moves upward in FIG. The valve 13 restricts the sub flow path 8b in the flow path 8 on the other side to reduce the flow path area.

  When the piston speed further increases after the piston speed reaches the highest speed region, the valve body 14 in the throttle valve 13 on the other side has a flow path area corresponding to the degree of pressure reduction of the sub flow path 8b. The sub-passage 8b is closed by contacting the annular valve seat 27f of the partitioning member 27 and finally shutting off the communication between the one chamber 41 and the other chamber 42 through the through hole 27e. The one chamber 41 and the other chamber 42 are communicated with each other only by 8a to minimize the channel area of the channel 8 on the other side.

  That is, as shown in FIG. 2, the damping characteristic during the period when the piston speed reaches the high speed region and the other side flow path 8 is throttled for the first time after the other side throttle valve 13 is throttled is gradually limited as shown in FIG. 2. Therefore, the inclination becomes larger than that in the high speed region, the damping force increases as the speed of the piston 1 increases, and the throttle valve 13 on the other side minimizes the flow area of the flow path 8 on the other side. As the piston speed increases later, the slope of the damping characteristic decreases again, but the damping force increases as the flow path area decreases.

  As described above, in the valve structure of the shock absorber according to the present embodiment, when the piston speed is in the medium speed region, the piston speed is reduced when the piston speed reaches the high speed region while keeping the damping force low. The damping force can be made larger than when it is in the middle speed range, and even when the piston speed reaches the high speed range, the damping force will not be insufficient, vibration will be sufficiently suppressed, and the ride comfort in the vehicle Can be improved.

  In addition, in a situation where the amplitude at which the shock absorber is fully extended is large and the piston speed reaches the high speed region, the damping force generated by the shock absorber can be increased. It is possible to reduce the impact at the time of maximum extension.

  Further, since the secondary pressure between the orifices 16a and 17a is introduced into the pressure chambers 18 and 19 in the communication passage 15, only by installing a single communication passage 15, the throttle valve 11, Since both of them can be operated, the processing is simplified and the manufacturing cost is not deteriorated.

  In this case, the throttle valve 11 on one side and the throttle valve 13 on the other side reduce the flow area of the one-side flow path 7 and the other-side flow path 8 corresponding to both strokes of the expansion / contraction stroke of the shock absorber. Therefore, the damping force can be increased when the piston speed is in the high speed region, and a further higher damping force can be generated in the region where the piston speed is at most high.

  It should be noted that the flow area of the corresponding one-side flow path 7 and the other-side flow path 8 in the one-side throttle valve 11 during the expansion stroke and in the other-side throttle valve 13 during the compression stroke. Although it operates so as to reduce, by adjusting the pressure receiving areas of the springs 25 and 29 and the pressure chambers 18 and 19 and weakening the pressure reducing action of the sub flow paths 7b and 8b by the throttle valves 11 and 13 on the one side and the other side. It is also possible to set so that the above-mentioned operation is not exhibited at least in the practical use range of the shock absorber. In this case, even if the piston speed reaches the highest speed region, the throttle valve 11 on the one side and the throttle valve 13 on the other side. Since it does not operate, it is possible to realize the attenuation characteristic as shown in FIG.

  In addition, since the configuration in which the rear surfaces of the leaf valves 10a and 10b are energized by springs is not employed, there is no concern that variations in the urging force of the springs will cause variations in the damping characteristics of each product. The reliability and stability of the valve structure is improved.

  Note that the annular inclined surfaces 22g and 27g may not be provided in order to achieve the above-described effects. However, in the valve structure according to the present embodiment, the annular inclined surfaces 22g and 27g are provided to displace the valve bodies 12 and 14. Since the flow area reduction gain of each of the flow paths 7 and 8 with respect to the amount is reduced, the throttle valves 11 and 13 have a pressure difference between the pressure in the one chamber 41 or the other chamber 42 and the secondary pressure in the communication path 15. By gradually decreasing the flow path area in accordance with the increase, the rate of increase of the damping force with respect to the increase of the piston speed when the piston speed is in the high speed region can be reduced, and the damping force changes rapidly. In addition, since the vehicle occupant does not feel uncomfortable due to a sudden change in damping force or feel a shock, the ride comfort can be further improved.

  In the present embodiment, in order to explain the change of the damping characteristic, the piston speed is provided with sections of low speed, medium speed, and high speed, but the speed of the boundary between these sections is arbitrarily set. be able to.

  The springs 25 and 29 for biasing the valve bodies 12 and 14 in the throttle valves 11 and 13 are coil springs in the drawing, but this is, for example, a disc spring or a leaf spring, rubber or the like. Or an elastic body.

  The one-side flow path 7 and the other-side flow path 8 include main flow paths 7a, 8a and sub-flow paths 7b, 8b, and the one-side and the other-side throttle valves 11, 13 are sub-flow paths 7b. , 8b is closed to reduce the flow passage area, so that when the flow passage area is at a minimum state, only the main flow passages 7a, 8a are in communication and the piston speed is in the high speed region. It is not necessary to set the damping force of the flow path 7 and 8 with the degree of restriction of the flow paths 7, and also in this respect, the damping characteristic is stable when the piston speed is higher than the high speed, and the damping characteristic varies from product to product. Nor. Further, as described above, since it is not necessary to set the damping force according to the degree of restriction of the flow paths 7 and 8, there is a concern that even if there is some variation in the spring rigidity of the springs 25 and 30, the damping characteristics may change greatly. Nor.

  Further, the main flow paths 7a, 8a and the sub flow paths 7b, 8b can be formed upstream of the ports 2a, 2b simply by stacking the partition members 22, 27 on the piston 1 which is a valve disk. 7a, 8a and sub-channels 7b, 8b are easily formed, and there is an advantage that the valve structure can be easily assembled.

  Further, in the above description, the valve structure of the present invention has been described using the example embodied in the damping valve on both sides of the pressure expansion of the piston portion of the shock absorber, but it can also be embodied in the base valve portion. Of course, the present invention can be applied to a valve of a shock absorber that functions as a damping force generating element that generates a damping force. 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 in which the valve structure in one embodiment was embodied. It is a figure which shows an example of the damping characteristic in the buffer which embodied the valve | bulb structure of the buffer of one embodiment. It is a figure which shows the other example of 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. It is a figure which shows the damping characteristic in 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 Pressure port 2b which is a port on one side Extension port 3a, 3b which is a port on the other side Window 5 Piston rod 5a Piston rod tip 5b Piston rod step 5c Piston rod screw groove 7 Flow path 7a, 8a Main flow path 7b, 8b Sub flow path 8 Flow path 10a on the other side Leaf valve 10b on the other side Leaf valve 11 on the other side Throttle valves 12, 14 Valve bodies 12a, 14a Inner cylinders 12b and 14b in the valve element Inner peripheral flanges 12c and 14c in the valve element Outer flanges 12d and 14d in the valve element Valve cylinders 12e and 14e in the valve element 13 Groove 13 in the valve element Other throttle valve 15 Communication path 15a Vertical hole 15b Horizontal hole 15c, 15d Through hole 16, 17 Plug 16a, 17a Orifice 18, 19 Pressure chamber 21, 6 Spacers 22 and 27 Partition members 22a and 27a Bottom portions 22b and 27b in the partition member Cylindrical portions 22c and 27c in the partition member Holes 22d, 22e, 27d and 27e Through holes 22f and 27f in the partition member Annular valves in the partition member Seats 22g, 27g Annular inclined surfaces 23, 28 in partition member Holding members 23a, 28a Small diameter portions 23b, 28b in holding member Large diameter portions 23c, 28c in holding member Annular grooves 23d, 28d in holding member Passage 24 in holding member Stopper 25 29 Spring 30 Piston nut 40 Cylinder 41 One chamber 42 Other chamber R1, R2 chamber

Claims (7)

A valve disc having a pair of ports for separating the one chamber and the other chamber in the shock absorber and communicating the one chamber and the other chamber, and one port stacked on the side surface of the one chamber of the valve disc. In a valve structure of a shock absorber having a leaf valve on one side that opens and closes and a leaf valve on the other side that is stacked on the other chamber side surface of the valve disc and opens and closes other ports, the one chamber communicates with each port. One side provided with a valve body that is provided in the middle of the one-side flow path, the other chamber communicating with each port and the one-side flow path, and can reduce the flow area A throttle valve on the other side, a throttle valve on the other side provided with a valve body provided in the middle of the flow path on the other side and capable of reducing the flow area, a communication passage communicating the one chamber and the other chamber, A pair of orifices arranged in series in the middle of the passage; In the middle of the communication path in the direction of reducing the flow path area to the valve body on one side and acting the pressure between each orifice on the valve body on the other side, in the middle of the communication path in the direction of reducing the flow path area to the valve body on the other side A valve structure of a shock absorber, wherein pressure between each orifice is applied. In the middle of the communication path, the pressure between the orifices is guided and the pressure area on the one side is urged in the direction in which the flow passage area is reduced by the pressure. And a pressure chamber on the other side for energizing a valve body in the throttle valve on the other side in a direction in which the pressure between the orifices is guided and the flow passage area is reduced by the pressure. The valve structure of the shock absorber according to 2. When the throttle valve on one side is in the middle of the flow path on one side and depressurizes the port side from the valve body, the flow path can be reduced by the pressure reduction, and the throttle valve on the other side 3. The shock absorber valve structure according to claim 1, wherein when the pressure is reduced on the port side of the valve body in the middle of the flow path, the flow path can be reduced by the pressure reduction. 4. The shock absorber valve structure according to claim 1, wherein the flow path includes a main flow path and a sub flow path, and the throttle valve reduces the flow path area by closing the sub flow path. . 5. The buffer structure for a shock absorber according to claim 4, wherein a partition member is provided which is stacked on the valve disk and forms a chamber communicating with the main flow path and the sub flow path upstream of the port. The valve body is formed in a cylindrical shape, and is provided with a holding member that is immovable in the axial direction with respect to the valve disk, and the valve body and the holding member are slidably mounted on the outer periphery of the holding member. 6. The shock absorber valve structure according to claim 2, wherein a pressure chamber is defined therebetween. The valve structure of the shock absorber according to any one of claims 4 to 6, wherein the flow path area of the sub flow path is reduced by the approach of the valve body to the partition member.

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