JP6487815B2 - shock absorber - Google Patents

Description

  The present invention relates to a shock absorber.

  In the damping force generation mechanism described in Patent Document 1, an annular leaf valve that closes the passage of the piston is slidably fitted to a guide shaft, and is also slidably fitted to the guide shaft via a main valve. The leaf valve is biased by a spring with the inner peripheral side facing the piston.

  With the above structure, in a region where the operating speed of the shock absorber is low, the leaf valve is bent by the differential pressure between the two pressure chambers defined by the piston, and the passage is opened. In the middle and high speed regions, the differential pressure acting on the leaf valve increases, so that the leaf valve and the main valve overcome the urging force of the spring and move to the spring side, and the passage is more greatly opened.

  According to this, an increase in the damping force of the shock absorber in the medium / high speed region is suppressed. Therefore, the riding comfort of the vehicle can be improved.

JP-A-9-291196

  In recent years, in order to improve the riding comfort of a vehicle, there is a demand for further suppressing an increase in damping force of a shock absorber in a medium / high speed region.

  The present invention has been made in view of such a technical problem, and an object of the present invention is to suppress an increase in damping force of a shock absorber in a medium / high speed region.

  A first invention is a shock absorber, a cylinder filled with hydraulic fluid, a valve disc that partitions a pressure chamber in the cylinder, and a valve disc, wherein the hydraulic fluid passes when the shock absorber is operated. And a damping force generating mechanism that provides resistance to the flow of hydraulic fluid passing through the first and second passages, and the damping force generating mechanism is a shaft provided coaxially with the valve disk. A main valve that is slidably fitted to the part and closes the first passage by a flange formed at one end, an annular leaf valve that is provided on the outer periphery of the main valve and closes the second passage, and a shaft part And an elastic member that urges the flange portion of the main valve toward the valve disk via a leaf valve.

  In the first invention, in a region where the operating speed of the shock absorber is low, the leaf valve is bent by the differential pressure between the two pressure chambers partitioned by the valve disc, and the second passage is opened. In the middle and high speed regions, the differential pressure acting on the leaf valve and the main valve increases, so that the leaf valve and the main valve overcome the urging force of the elastic member and move toward the elastic member, Two passages are greatly opened.

  The second invention is characterized in that a fixing portion for fixing the inner peripheral side of the leaf valve to the flange portion is provided on the other end side of the main valve.

  In the second invention, the leaf valve can be fixed to the main valve by the fixing portion. According to this, when assembling the damping force generating mechanism, the main valve and the leaf valve can be set as sub-assemblies in advance. Therefore, the damping force generating mechanism can be easily assembled.

  ADVANTAGE OF THE INVENTION According to this invention, the raise of the damping force of the shock absorber in a medium-high speed area | region can be suppressed.

It is a fragmentary sectional view of the shock absorber which concerns on embodiment of this invention. It is an enlarged view around a damping force generation mechanism.

  Hereinafter, a shock absorber 100 according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  The shock absorber 100 is a device that is interposed between a vehicle body and an axle of a vehicle (not shown), for example, and generates damping force to suppress vibration of the vehicle body.

  As shown in FIG. 1, the shock absorber 100 includes a cylinder 1, a piston 2 as a valve disk that is slidably inserted into the cylinder 1 and partitions the inside of the cylinder 1 into an expansion side chamber 110 and a pressure side chamber 120, 1 and a piston rod 3 that is inserted into 1 so as to be able to advance and retract and is connected to the piston 2.

  The shock absorber 100 is a single-cylinder shock absorber and includes a free piston 4 that is slidably inserted into the cylinder 1 to define a gas chamber 130. On the outer periphery of the free piston 4, a seal member 4a for maintaining the airtightness of the gas chamber 130 is provided.

  The cylinder 1 has an end on the expansion side chamber 110 side sealed by a head member (not shown) that slidably supports the piston rod 3, and an end on the gas chamber 130 side sealed by a bottom member (not shown). Sealed. A connecting member 1a for attaching the shock absorber 100 to the vehicle is provided at the end on the gas chamber 130 side.

  A male screw 3a for attaching the shock absorber 100 to the vehicle is formed at the end of the piston rod 3 that extends from the cylinder 1.

  The extension side chamber 110 and the pressure side chamber 120 are filled with hydraulic oil as hydraulic fluid. A seal member (not shown) is provided between the piston rod 3 and the head member to prevent hydraulic oil from leaking outside the shock absorber 100.

  When the shock absorber 100 contracts and the piston rod 3 enters the cylinder 1, the gas in the gas chamber 130 is compressed by the volume of the piston rod 3 that has entered, and the free piston 4 moves toward the gas chamber 130. . When the shock absorber 100 extends and the piston rod 3 retracts from the cylinder 1, the gas in the gas chamber 130 expands by the volume of the retracted piston rod 3, and the free piston 4 moves toward the pressure side chamber 120. Thereby, the volume change in the cylinder 1 when the shock absorber 100 is operated is compensated.

  The piston 2 includes a first passage 2a, a second passage 2b, and a third passage 2c that communicate the extension side chamber 110 and the pressure side chamber 120.

  On the side of the expansion side chamber 110 of the piston 2, a leaf valve 5 is provided that closes the third passage 2c when the shock absorber 100 is extended and opens the third passage 2c when the shock absorber 100 is contracted.

  On the pressure side chamber 120 side of the piston 2, a damping force generation mechanism 10 that closes the first passage 2a and the second passage 2b when the shock absorber 100 is contracted and opens the first passage 2a and the second passage 2b when the shock absorber 100 is contracted. Is provided.

  The leaf valve 5, the piston 2, and the damping force generation mechanism 10 are fixed by a piston nut 6 to a small diameter portion 3 b formed at the end of the piston rod 3 on the side inserted into the cylinder 1.

  Hereinafter, the damping force generation mechanism 10 will be described in detail with reference to FIG.

  As shown in FIG. 2, the damping force generating mechanism 10 is fitted to the small diameter portion 3 b of the piston rod 3 and is provided with a collar 11 as a shaft provided coaxially with the piston 2, and slidably fitted to the collar 11. A main valve 12 that closes the first passage 2a by a flange 12a formed at the end portion on the piston 2 side, and an annular leaf valve 13 that is provided on the outer periphery of the main valve 12 and closes the second passage 2b. And a spring 14 as an elastic member that is provided on the outer periphery of the collar 11 and biases the flange 12a of the main valve 12 toward the piston 2 via the leaf valve 13 and the like.

  A circular recess 2d is formed in a portion of the piston 2 where the flange 12a of the main valve 12 abuts, and the first passage 2a is open to the bottom surface of the recess 2d.

  The depth of the concave portion 2d is such that the surface of the flange portion 12a on the pressure side chamber 120 side and the end surface 2e of the piston 2 on the pressure side chamber 120 side are flush with each other in the state where the main valve 12 closes the first passage 2a. The end surface 2e on the pressure side chamber 120 side is set to be slightly higher.

  As a result, as shown in FIG. 2, in a state where the main valve 12 closes the first passage 2a, the leaf valve 13 abuts against the surface of the flange portion 12a on the pressure side chamber 120 side, and the end surface 2e of the piston 2 It abuts and closes the opening of the second passage 2b on the pressure side chamber 120 side.

  The spring 14 is held in a compressed state between an annular spring receiving member 15 provided on the outer periphery of the main valve 12 and a bowl-shaped spring receiving portion 6 a formed on the outer periphery of the piston nut 6. A washer 16 is provided on the outer periphery of the main valve 12 between the spring receiving member 15 and the leaf valve 13. As a result, the spring 14 biases the flange portion 12a of the main valve 12 toward the piston 2 via the spring support member 15, the washer 16, and the inner peripheral side of the leaf valve 13.

  The washer 16 forms a space for the leaf valve 13 to bend toward the pressure side chamber 120 between the leaf valve 13 and the spring receiving member 15 and defines a starting point on the inner peripheral side when the leaf valve 13 is bent. Yes. Note that the washer 16 and the spring receiving member 15 may be integrally formed instead of being provided separately.

  An annular guide portion 15 a for preventing the spring 14 from being displaced in the radial direction is provided on the outer periphery of the spring receiving member 15 so as to protrude toward the spring 14. Similarly, an annular guide portion 6b is provided on the outer periphery of the spring receiving portion 6a of the piston nut 6 so as to protrude toward the spring 14 side. Note that the guide portion 15a and the guide portion 6b may not be provided.

  Moreover, in this embodiment, the fixing | fixed part which fixes the inner peripheral side of the leaf valve 13, the washer 16, and the spring receiving member 15 to the edge part on the opposite side to the collar part 12a of the main valve 12 between the collar parts 12a. A nut 17 is provided. Note that the washer 16, the spring receiving member 15, and the nut 17 may be integrally formed.

  According to this, when the damping force generating mechanism 10 is assembled, the main valve 12, the leaf valve 13, etc. can be set in advance as subassemblies. Therefore, the damping force generation mechanism 10 can be easily assembled.

  The shock absorber 100 is configured as described above, and at the time of contraction operation, the outer peripheral side of the leaf valve 5 is bent by the differential pressure between the expansion side chamber 110 and the pressure side chamber 120 to open the third passage 2c and The leaf valve 5 provides resistance to the flow of hydraulic fluid that passes from the pressure side chamber 120 to the extension side chamber 110.

  Further, when the shock absorber 100 is contracted, the first passage 2 a is closed by the main valve 12, and the second passage 2 b is closed by the leaf valve 13.

  The leaf valve 5 may be composed of a plurality of leaf valves, and the number, outer diameter, and thickness of the leaf valves are appropriately changed according to desired damping force characteristics.

  Further, when the shock absorber 100 is extended and the operating speed of the shock absorber 100 is low, that is, when the differential pressure between the expansion side chamber 110 and the pressure side chamber 120 is small, the outer peripheral side of the leaf valve 13 is bent. While the second passage 2b is opened, the leaf valve 13 provides resistance to the flow of hydraulic oil that moves from the expansion side chamber 110 to the compression side chamber 120 through the second passage 2b.

  At this time, the main valve 12 is pressed against the piston 2 by the urging force of the spring 14, and the first passage 2 a is closed by the main valve 12. In addition, when the shock absorber 100 is extended, the third passage 2 c is closed by the leaf valve 5.

  When the operating speed of the shock absorber 100 enters a medium high speed region, the flow rate of the operating oil increases, and the leaf valve 13 gives the flow of operating oil that moves from the expansion side chamber 110 to the compression side chamber 120 through the second passage 2b. Resistance increases. For this reason, the differential pressure between the expansion side chamber 110 and the pressure side chamber 120 increases, and the main valve 12 and the leaf valve 13 on which the differential pressure acts overcomes the urging force of the spring 14 and moves toward the spring 14 to move to the first passage. 2a and the 2nd channel | path 2b are open | released largely.

  After the first passage 2a and the second passage 2b are largely opened, the resistance that the main valve 12 and the leaf valve 13 give to the flow of hydraulic oil passing through the first passage 2a and the second passage 2b is less likely to increase. An increase in the damping force of the shock absorber 100 is suppressed.

  Thus, in this embodiment, when the shock absorber 100 is extended, the first passage 2a and the second passage 2b are largely opened in a region where the operation speed is medium to high. For this reason, for example, the flow passage area through which the hydraulic oil can pass can be made larger than when only one passage is opened in the medium to high speed region. Therefore, as described above, the resistance that the main valve 12 and the leaf valve 13 give to the flow of hydraulic oil passing through the first passage 2a and the second passage 2b is less likely to increase, and the damping force of the shock absorber 100 is further increased. It is suppressed.

  The leaf valve 13 may be composed of a plurality of leaf valves, and the number, outer diameter, and thickness of the leaf valves are appropriately changed according to desired damping force characteristics.

  Further, the valve opening pressure at which the outer peripheral side of the leaf valve 13 is bent and the second passage 2b is opened in the low speed region is a step between the pressure side chamber 120 side surface of the flange 12a and the end surface 2e of the piston 2 on the pressure side chamber 120 side. It can be changed by adjusting.

  Further, the valve opening pressure at which the main valve 12 and the leaf valve 13 move toward the spring 14 and the first passage 2a and the second passage 2b are largely opened in the middle and high speed range is adjusted by adjusting the urging force of the spring 14. It can be changed.

  As described above, according to the present embodiment, the leaf valve 13 is bent by the differential pressure between the expansion side chamber 110 and the pressure side chamber 120 when the shock absorber 100 is extended and the operation speed is low. The second passage 2b is opened. Further, in the medium / high speed region, the differential pressure acting on the leaf valve 13 and the main valve 12 increases, so that the leaf valve 13 and the main valve 12 overcome the urging force of the spring 14 and move toward the spring 14, The first passage 2a and the second passage 2b are greatly opened. Therefore, an increase in the damping force of the shock absorber 100 in the medium / high speed region can be suppressed.

  In addition, a nut 17 for fixing the inner peripheral side of the leaf valve 13, the washer 16, and the spring receiving member 15 to the flange 12a is provided at the end opposite to the flange 12a of the main valve 12. When the damping force generation mechanism 10 is assembled, the main valve 12, the leaf valve 13, etc. can be set as sub-assemblies in advance. Therefore, the damping force generation mechanism 10 can be easily assembled.

  Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

  The shock absorber 100 is provided in the cylinder 1 filled with hydraulic oil, the piston 2 that defines the pressure chamber (extension side chamber 110, the pressure side chamber 120) in the cylinder 1, and the piston 2, and when the shock absorber 100 is extended. A damping force generation mechanism including a first passage 2a and a second passage 2b through which the hydraulic oil passes, and a damping force generation mechanism 10 that provides resistance to the flow of the hydraulic oil through the first passage 2a and the second passage 2b. Reference numeral 10 denotes a main valve 12 that is slidably fitted to a collar 11 that is provided coaxially with the piston 2, and that is provided on the outer periphery of the main valve 12 and that closes the first passage 2 a with a flange 12 a formed at one end. An annular leaf valve 13 that closes the second passage 2b and an outer periphery of the collar 11, and the flange 12a of the main valve 12 is connected to the piston via the leaf valve 13. Characterized in that it has a spring 14 for urging the towards.

  In this configuration, when the shock absorber 100 is extended and the operating speed is low, the leaf valve 13 is bent due to the differential pressure between the expansion side chamber 110 and the compression side chamber 120 defined by the piston 2, and the second The passage 2b is opened. Further, in the medium / high speed region, the differential pressure acting on the leaf valve 13 and the main valve 12 increases, so that the leaf valve 13 and the main valve 12 overcome the urging force of the spring 14 and move toward the spring 14, The first passage 2a and the second passage 2b are greatly opened. Therefore, an increase in the damping force of the shock absorber 100 in the medium / high speed region can be suppressed.

  Further, the other end side of the main valve 12 is provided with a nut 17 for fixing the inner peripheral side of the leaf valve 13 between the flange portion 12a.

  In this configuration, the leaf valve 13 can be fixed to the main valve 12 by the nut 17. According to this, when the damping force generating mechanism 10 is assembled, the main valve 12 and the leaf valve 13 can be set as sub-assemblies in advance. Therefore, the damping force generation mechanism 10 can be easily assembled.

  As mentioned above, although embodiment of this invention was described, the said embodiment is only what showed a part of application example of this invention, and in the meaning which limits the technical scope of this invention to the specific example of said embodiment. Absent.

  For example, in the above embodiment, hydraulic oil is used as the hydraulic fluid, but other liquids such as water may be used.

  In the above embodiment, the present invention is applied to the shock absorber 100 that is a single-cylinder shock absorber. However, the present invention may be applied to a compound-type shock absorber or the like. In the case of a dual shock absorber, the present invention may be applied to a valve disk provided at the bottom of the cylinder.

  In the above embodiment, the collar 11 is provided as a shaft portion. However, the shaft portion may be provided integrally with a valve disk such as the piston 2 or the piston nut 6.

  Moreover, in the said embodiment, although the damping force generation mechanism 10 is provided in the compression side chamber 120 side of piston 2, you may provide in the extension side chamber 110 side of piston 2. FIG.

  Moreover, in the said embodiment, although the spring receiving part 6a is provided in the piston nut 6, you may provide the spring receiving member as a spring receiving part separately.

  Moreover, in the said embodiment, although the damping force generation mechanism 10 is provided with the spring 14 as an elastic member, you may provide a rubber pipe, a disc spring, etc. as an elastic member, for example.

  In the above embodiment, the damping force generation mechanism 10 includes the nut 17 as a fixed portion. However, for example, the end portion of the main valve 12 may be fixed by caulking the end portion of the main valve 12. A C pin may be provided as a fixed portion.

  In the above embodiment, the nut 17 is provided at the end of the main valve 12 opposite to the flange 12a. However, if the main valve 12, the leaf valve 13 and the like are not sub-assemblies, the nut 17 is unnecessary. is there.

DESCRIPTION OF SYMBOLS 100 ... Shock absorber, 110 ... Extension side chamber (pressure chamber), 120 ... Pressure side chamber (pressure chamber), 1 ... Cylinder, 2 ... Piston (valve disk) 2a ... 1st Passage 2b second passage 10 damping force generation mechanism 11 collar (shaft portion) 12 main valve 12a collar 13 leaf valve 14 ... spring (elastic member), 17 ... nut (fixed part)

Claims (2)

A shock absorber,
A cylinder filled with hydraulic fluid;
A valve disk that defines a pressure chamber in the cylinder;
A first passage and a second passage which are provided in the valve disc and through which the hydraulic fluid passes when the shock absorber is operated;
A damping force generating mechanism that provides resistance to the flow of the hydraulic fluid passing through the first passage and the second passage;
With
The damping force generation mechanism is
A main valve that is slidably fitted to a shaft provided coaxially with the valve disk and closes the first passage by a flange formed at one end;
An annular leaf valve provided on an outer periphery of the main valve and closing the second passage;
An elastic member provided on an outer periphery of the shaft portion and biasing the flange portion of the main valve toward the valve disk via the leaf valve;
A shock absorber characterized by comprising: The shock absorber according to claim 1,
The other end side of the main valve is provided with a fixing portion that fixes the inner peripheral side of the leaf valve between the flange portion,
Shock absorber characterized by that.

Images