JP2005147209A - Vehicular hydraulic shock absorbing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular hydraulic shock absorbing device for preventing excessive inner pressure of a piston side oil chamber while reducing its cost with a less number of parts, and to provide multicylindrical hydraulic shock absorbers constituting the same. <P>SOLUTION: The vehicular hydraulic shock absorbing device 1 comprises the hydraulic shock absorbers 100, 200 provided on the right and left sides of a wheel. The hydraulic shock absorber 100 on one side has a piston-valve assembly 101 at the front end of a piston rod 15 for substantially generating only pressure side damping force and an oil path 50 in a piston rod side oil chamber 41A for volume compensation for the piston rod 15, which normally opens it to an oil sump chamber 43. The hydraulic shock absorber 200 on the other side has a piston-valve assembly 201A at the front end of the piston rod 15 for substantially generating only expansion side damping force and an oil path 70 for volume compensation for the piston rod 15, which normally opens a piston side oil chamber 41B to the oil sump chamber 43. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  According to the present invention, a lower portion of a pair of hydraulic shock absorbers arranged on the left and right sides of a wheel is attached to a common axle or an axle side member, and a hydraulic shock absorber that substantially generates only a compression side damping force is provided on one of the left and right sides. A unit-type hydraulic shock absorber, in which a hydraulic shock absorber that generates substantially only the expansion-side damping force is disposed on the other side, and one hydraulic shock absorber is configured by a pair of right and left hydraulic shock absorbers It is related with the hydraulic shock absorber which comprises.

  Patent Document 1 discloses a motorcycle having a compression leg 5 that essentially exhibits a damping function only during a compression movement and a return leg 6 that essentially exhibits a damping function only during a return (extension) movement. A front fork is disclosed.

  The front fork of Patent Document 1 has a pressure chamber unit 22 connected to the outer periphery of the lower portion of the inner tube 8 as shown in FIG. The pressure chamber unit 22 includes a gas (nitrogen gas) in the space 23 and a displaceable separation piston 24, and a control valve unit 25 (pressure-side base valve device) is provided between the space 17 and the pressure chamber unit 22. Is provided.

The control valve unit 25 (pressure side base valve device) includes an adjusting screw 26 for setting a bleed amount and a valve function body. The valve function body is mainly provided to generate a compression side damping force for the hydraulic oil corresponding to the volume of entry of the piston rod 10 into the damper cylinder 13.
JP2001-165221 ([0029], [0032])

  In the thing of patent document 1, since each leg is equipped with the control valve unit 25 (pressure side base valve apparatus) which generates the compression side damping force with respect to the hydraulic oil for the approach volume of a piston rod, the following problem There is a point.

  (1) Since the control valve unit 25 (pressure-side base valve device) is provided, the number of parts increases and the cost increases. As a result, it is difficult to apply to hydraulic shock absorbers such as small motorcycles with cost constraints.

  (2) Normally, the compression side damping force generated in the compression side base valve device is set larger than the compression side damping force generated in the piston portion at the tip of the piston rod. The reason is to fill the piston rod side oil chamber with hydraulic oil so that negative pressure is not generated in the piston rod side oil chamber when the piston rod moves to the extension stroke.

  However, if the compression-side damping force generated at the compression-side base valve section is to be greater than the compression-side damping force of the piston section, the piston rod's cross-sectional area is usually the piston's annular cross-sectional area (from the piston's cross-sectional area Therefore, it is necessary to increase the pressure in the piston side oil chamber to increase the differential pressure.

  As a result, the internal pressure of the piston-side oil chamber becomes excessive. In particular, in a hydraulic shock absorber (for example, Japanese Utility Model Publication No. 59-149149) in which only the orifice hole is provided in the pressure-side base valve portion, the valve constituting the pressure-side base valve portion. The body 22 and the valve seat 23 may be destroyed.

  The compression side damping force at the piston part is the value obtained by multiplying the sectional area of the piston by subtracting the sectional area of the piston rod from the annular sectional area and the differential pressure of the oil chambers on both sides of the piston part. The generated compression side damping force is a value obtained by multiplying the cross-sectional area of the piston rod by the pressure difference between the chambers on both sides of the compression side base valve portion.

  (3) Patent Document 1 discloses a front fork of a motorcycle, but a hydraulic shock absorber on the rear wheel side of a motorcycle having a relatively small displacement, such as disclosed in Japanese Utility Model Publication No. 59-149149, An embodiment when applied to a so-called double cylinder type hydraulic shock absorber is not disclosed.

  An object of the present invention is to provide a hydraulic shock absorber for a vehicle, which can reduce the number of parts, reduce costs, and prevent the internal pressure of a piston-side oil chamber from becoming excessive, and a vehicle hydraulic shock absorber. It is to provide a double cylinder type hydraulic shock absorber.

  According to the first aspect of the present invention, hydraulic shock absorbers are provided on the left and right sides of the wheel, substantially only the compression side damping force is generated in the one side hydraulic shock absorber, and only the extension side damping force is substantially generated in the other side hydraulic shock absorber. In the vehicle hydraulic shock absorber, the one-side hydraulic shock absorber is configured such that an inner cylinder is erected at the bottom of the outer cylinder, and a rod guide provided at the opening of the inner cylinder, A piston / valve assembly that generates substantially only a compression damping force is provided at the tip of a piston rod that is slidably inserted into the inner cylinder, and the piston rod side that accommodates the piston rod is provided in the inner cylinder. An oil chamber and a piston-side oil chamber that does not accommodate the piston rod are partitioned, the space between the opening of the outer cylinder and the piston rod is sealed, and a lower oil reservoir chamber is provided between the inner cylinder and the outer cylinder. An upper gas chamber, and the oil reservoir in the piston rod side oil chamber An oil passage for volume compensation of the piston rod that always opens is provided, and the other-side hydraulic shock absorber has an inner cylinder erected at the bottom of the outer cylinder, and the opening of the inner cylinder. A piston / valve assembly that generates substantially only the expansion-side damping force is provided at the tip of the piston rod slidably inserted into the inner cylinder through the provided rod guide. A piston rod side oil chamber that houses the piston rod and a piston side oil chamber that does not contain the piston rod, and seals between the opening of the outer cylinder and the piston rod, and between the inner cylinder and the outer cylinder Between, a lower oil reservoir chamber and an upper gas chamber are provided, and the piston-side oil chamber is provided with an oil passage for volume compensation of the piston rod that always opens to the oil reservoir chamber.

  The invention according to claim 2 is characterized in that the inner cylinder is erected at the bottom of the outer cylinder, and the tip of the piston rod is slidably inserted into the inner cylinder via a rod guide provided at the opening of the inner cylinder. A piston / valve assembly that substantially generates only a compression damping force, and a piston rod side oil chamber that houses the piston rod and a piston side oil chamber that does not contain the piston rod are defined in the inner cylinder, While sealing between the opening of the outer cylinder and the piston rod, a lower oil reservoir chamber and an upper gas chamber are provided between the inner cylinder and the outer cylinder. It is a vehicle hydraulic shock absorber provided with an oil passage for volume compensation of the piston rod that always opens in the oil reservoir chamber.

  According to a third aspect of the present invention, in the second aspect of the invention, an opening of the volume compensating oil passage is provided below the oil surface of the oil reservoir chamber, and the extended position of the piston rod is set to the oil passage. The oil passage is always opened to the oil reservoir chamber by being positioned below the opening.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, by further providing an extended position restricting member for the piston rod between the inner cylinder side and the piston rod side, the volume compensation is provided. An oil passage is always opened in the oil reservoir chamber.

  According to a fifth aspect of the present invention, in the invention according to any one of the second to fourth aspects, the extended position restricting member comprises a cylindrical collar fixed to an upper inner periphery of the inner cylinder, A coil spring is interposed between the piston rod and a buffer at the time of maximum extension.

  According to the sixth aspect of the present invention, the tip of the piston rod is slidably inserted into the inner cylinder through a rod guide provided at the bottom of the outer cylinder and provided in the opening of the inner cylinder. The piston / valve assembly that generates only the expansion side damping force is provided in the part, and the piston rod side oil chamber that accommodates the piston rod and the piston side oil chamber that does not accommodate the piston rod are defined in the inner cylinder. And sealing between the opening of the outer cylinder and the piston rod, and providing a lower oil reservoir chamber and an upper gas chamber between the inner cylinder and the outer cylinder. The hydraulic shock absorber is provided with an oil passage for volume compensation of the piston rod that is always open to the oil reservoir chamber.

(Claim 1)
(a) (1) When compressing the hydraulic shock absorber on one side, the hydraulic oil equivalent to the piston cross-sectional area (including the cross-sectional area of the piston rod) passes through the piston disk valve and passes through the piston disk valve. Generate compression side damping force. As a result, even if the compression side base valve device is eliminated, the compression side damping force will not be insufficient.

  (2) The compression side base valve device was abolished, and the compression side damping force was generated by the piston. As a result, since the cross-sectional area of the piston is usually larger than the cross-sectional area of the piston rod, the same or more compression-side damping force can be generated even if the differential pressure between the oil chambers on both sides of the piston is reduced. Therefore, the pressure in the piston side oil chamber does not become excessive.

  (3) Since the opening of the volume compensating oil passage provided in the piston rod side oil chamber is provided at a position that is always open in the oil reservoir chamber, the gas chamber is located on the outer periphery of the piston rod side oil chamber. Even in the cylindrical hydraulic shock absorber, the operation of the piston is not hindered, and the air in the gas chamber is not caught in the inner cylinder.

  (4) The hydraulic shock absorber on the other side does not generate the compression side damping force at all or substantially, and therefore does not require the compression side base valve device.

  (5) Accordingly, both the hydraulic shock absorbers on one side and the other side can eliminate the pressure side base valve device. As a result, it is possible to provide a suspension device that can reduce costs and that does not cause excessive pressure in the piston-side oil chamber.

(Claim 2)
(b) `` A piston / valve assembly that generates only a compression damping force is provided at the tip of the piston rod that is slidably inserted into the inner cylinder. An oil passage for compensating the volume of the piston rod that is always open is provided. ”Therefore, the same effect as that of a of claim 1 can be obtained.

(Claim 3)
(c) “The volume of the oil passage opening for volume compensation is provided below the oil level in the oil reservoir chamber, and the fully extended position of the piston rod is positioned below the oil passage opening. In the double cylinder type hydraulic shock absorber in which the gas chamber is located on the outer periphery of the piston rod side oil chamber, the air in the gas chamber is not caught in the inner cylinder. .

(Claim 4)
(d) “The volume compensation oil passage was always opened in the oil reservoir chamber by providing a piston rod extension position regulating member between the inner cylinder side and the piston rod side.” The position restricting member can always open the oil passage for volume compensation into the oil reservoir.

(Claim 5)
(e) “A coil in which the extended position restricting member is formed of a cylindrical collar fixed to the upper inner periphery of the inner cylinder, and cushions at the time of maximum extension between the tip of the collar and the piston rod. A spring is interposed. ”By fixing a cylindrical collar to the inner circumference of the upper part of the inner cylinder, it becomes a piston rod extension position regulating member. As a result, the oil path for volume compensation with a simple configuration Can be positioned below the oil level.

  Since a coil spring is used as a buffer means at the time of maximum extension, even when the coil spring is attached to the inner cylinder side, there is a gap between the lines, so that the volume compensation oil passage (opening) is not blocked.

(Claim 6)
(f) `` A piston / valve assembly that generates substantially only the expansion side damping force is provided at the tip of the piston rod that is slidably inserted into the inner cylinder. An oil passage for compensating the volume of the piston rod that is always open is provided. ”Since the hydraulic shock absorber generates no or substantially no compression-side damping force, the compression-side base valve device can be eliminated. . Therefore, the cost can be reduced and the pressure in the piston side oil chamber does not become excessive.

  1 is an overall view showing a hydraulic shock absorber for a vehicle, FIG. 2 is a cross-sectional view showing one of the left and right hydraulic shock absorbers, FIG. 3 is an enlarged view of a main part of FIG. 2, and FIG. A) is an overall cross-sectional view, (B) is an enlarged view of a main part, FIG. 5 shows components of a compression side piston / valve assembly, (A) is a plan view showing an annular valve, and (B) shows a disk valve. Sectional view, (C) is a plan view showing a modification of the annular valve, FIG. 6 shows the operating state of the compression side piston / valve assembly, (A) is a sectional view showing the compressed state, and (B) shows the expanded state. FIG. 7 is a cross-sectional view showing the other hydraulic shock absorber on the left and right side, FIG. 8 is an enlarged view of a main part of FIG. 7, FIG. 9 shows an expansion side piston / valve assembly, and FIG. (B) is an enlarged view of the main part, FIG. 10 shows the operating state of the expansion side piston / valve assembly, and (A) is a sectional view showing the extended state. FIG, (B) is a sectional view showing a compressed state.

Example 1 (FIGS. 1 to 10)
As shown in FIG. 1, a vehicle hydraulic shock absorber 1 includes left and right hydraulic shock absorbers 100 and 200 provided on both left and right sides of the vehicle. This hydraulic shock absorber 1 is a rear damper for a two-wheeled vehicle or the like, in which wheel side tubes of left and right hydraulic shock absorbers are attached to both sides of a common axle, or a rear wheel-side hydraulic shock absorber for a two-wheeled vehicle or the like. Thus, the left and right hydraulic shock absorbers are configured to be attached to a common swing arm, and exclude the independent suspension type hydraulic shock absorber.

  One of the left and right hydraulic shock absorbers 100 is configured as shown in FIGS. 2 to 6, and the other left and right hydraulic shock absorbers 200 are configured as shown in FIGS. 7 to 10. The hydraulic shock absorber 1 includes a piston / valve assembly 101A (hereinafter referred to as “pressure side”) that is provided at the tip of a piston rod 15 inserted into the inner cylinder 12 of one hydraulic shock absorber 100 and generates substantially only a compression side damping force. A piston / valve assembly ”) and a piston / valve assembly which is provided at the tip of the piston rod 15 inserted into the inner cylinder 12 of the other hydraulic shock absorber 200 and generates substantially only the extension side damping force. A solid body 201A (hereinafter referred to as “extension side piston / valve assembly”) is provided, and the generation of the compression side damping force and the extension side damping force is shared by the left and right hydraulic shock absorbers 100 and 200, respectively.

(Hydraulic shock absorber 100) (FIGS. 2 to 6)
As shown in FIG. 2, the hydraulic shock absorber 100 has an inner cylinder 12 standing on the bottom 11 </ b> A of the outer cylinder 11, and a piston rod 15 slidably supported on a rod guide 14 provided in an opening of the inner cylinder 12. The piston rod 15 is inserted into the inner cylinder 12. The wheel side mounting portion 13 is fixed to the bottom portion 11A. Further, the hydraulic shock absorber 100 is provided with a shaft sealing means 16 such as an oil seal at the opening of the outer cylinder 11, the piston rod 15 is sealed by the shaft sealing means 16, the piston rod 15 projects from the outer cylinder 11, and the piston A vehicle body side mounting portion 17 is provided at the protruding end of the rod 15.

  The hydraulic shock absorber 100 has a spring bearing support member 18A fixed to the outer periphery of the outer cylinder 11, a spring bearing 18B having a cam surface supported on the back by the spring bearing support member 18A, and a vehicle body side mounting provided on the piston rod 15. A suspension spring 20 is interposed between spring receivers 19 formed in the portion 17. The initial set load of the suspension spring 20 can be adjusted by the rotation of the spring support 18B relative to the spring support member 18A. The hydraulic shock absorber 100 buffers the impact force received from the road surface when the vehicle travels by the spring reaction force of the suspension spring 20.

  The hydraulic shock absorber 100 has the above-described compression side piston / valve assembly 101 </ b> A in order to suppress the expansion and contraction vibration of the suspension spring 20.

  The compression side piston / valve assembly 101A has a stopper collar 31, a piston 32, a washer 33, a disk valve 34, an annular valve 35, a valve spring 36, and a valve stopper 37 inserted in this order into the small diameter portion of the piston rod 15. It is held by the caulking portion 38. The annular valve 35 and the disc valve 34 constitute a pressure side valve assembly 101B.

  The piston 32 includes a piston ring that slidably contacts the inner circumference of the inner cylinder 12, and the piston rod side oil chamber 41 </ b> A on the side where the piston rod 15 is inserted and the piston rod 15 are inserted inside the inner cylinder 12. It has a pressure expansion common oil passage 42 that is divided into a piston-side oil chamber 41B on the non-piston side and communicates the piston rod-side oil chamber 41A and the piston-side oil chamber 41B. The disc valve 34 and the annular valve 35 are slid on the inner periphery of the guide 37A of the valve stopper 37, and are provided so as to be axially movable with respect to the opening at the lower end of the pressure expansion common oil passage 42. Only the damping force is generated.

  The annular valve 35 (FIG. 5A) has a plurality of hole-shaped openings 35A, slides the inner periphery of the guide 37A of the valve stopper 37, and is more than the pressure increase common oil passage 42 on the lower end surface of the piston 32. The oil passage 42 is opened and closed by contacting and separating from the valve seat 32A formed on the outer peripheral side. The valve spring 36 biases the annular valve 35 toward the valve seat 32A. The disc valve 34 (FIG. 5B) is adjacent to the piston 32 side of the annular valve 35 around the guide 37 </ b> A of the valve stopper 37, and between the lower end surface of the piston 32 and the washer 33 and the annular valve 35. The outer periphery is sandwiched between the valve seat 32A of the piston 32 and closer to the common pressure oil passage 42 than the valve seat 32A, and the outer periphery is bent so as to be in contact with and separated from the annular valve 35 with the inner periphery being cantilevered. It deform | transforms and opens and closes the hole-shaped opening part 35A of the annular valve 35.

  Therefore, in the compression side piston / valve assembly 101A, during compression, the hydraulic pressure of the piston side oil chamber 41B is applied to the disc valve 34 from the hole-shaped opening 35A of the annular valve 35, as shown in FIG. By causing the disk valve 34 to bend and deform (in other words, to generate a pressure-side damping force), the oil in the piston-side oil chamber 41B flows into the piston rod-side oil chamber 41A via the pressure-extended common oil passage 42. 6B, the oil pressure in the piston rod side oil chamber 41A is applied to the disc valve 34 and the annular valve 35, and the disc valve 34 and the annular valve 35 are resisted against the urging force of the valve spring 36. Then, the oil in the piston rod side oil chamber 41A is caused to flow to the piston side oil chamber 41B via the oil passage 42 through a path that bypasses the disk valve 34, which is a valve means for generating a compression side damping force.

  The piston 32 includes two small-diameter hole orifices 32B that connect the pressure-extended common oil passage 42 to the piston-side oil chamber 41B on the circumference of the valve seat 32A.

  The hydraulic shock absorber 100 is provided with a lower oil reservoir chamber 43 and an upper gas chamber 44 in an annular space between the outer cylinder 11 and the inner cylinder 12, and the piston rod side oil chamber 41 </ b> A is always open to the oil reservoir chamber 43. The oil passage 50 for volume compensation of the piston rod 15 is provided in the inner cylinder 12.

  The oil passage 50 is provided below the oil level (L) of the oil reservoir 43, and the position of the piston 32 (FIGS. 2 and 3) when fully extended is positioned below the opening of the oil passage 50, The oil passage 50 is always opened to the piston rod side oil chamber 41 </ b> A and the oil reservoir chamber 43. In other words, the hydraulic shock absorber 100 is provided with the extended position regulating member 60 of the piston rod 15 between the inner cylinder 12 side and the piston rod 15 side, whereby the oil passage 50 is connected to the piston rod side oil chamber 41A and the piston rod side oil chamber 41A. The oil reservoir 43 is always opened. The extended position restricting member 60 includes a collar 61 fixed to the upper inner periphery of the inner cylinder 12 (a stopper ring 62 in which the outer periphery of the collar 61 is engaged with the inner periphery of the inner cylinder 12, and the rod guide 14. Sandwiched between). A rebound spring (coil spring) 63 is provided between the tip end of the collar 61 and the stopper collar 31 held by the piston rod 15 to provide a buffer at the time of maximum extension. regulate.

Accordingly, the hydraulic shock absorber 100 operates as follows.
(Compression process)
During compression of the hydraulic shock absorber 100, the outer cylinder 11, the inner cylinder 12 and the piston rod 15 are relatively compressed, and the suspension spring 20 is compressed. Further, the piston rod 15 enters the inner cylinder 12, and the oil in the piston side oil chamber 41B flows into the piston rod side oil chamber 41A through the orifice 32B of the piston 32 at a low speed, and is compressed by the throttle resistance of the orifice 32B during this time. Get damping force. Further, at medium and high speeds, the oil in the piston-side oil chamber 41B deflects and deforms the disk valve 34 in the pressure expansion common oil passage 42 of the piston 32 and flows into the piston rod-side oil chamber 41A. Get compression side damping force. The spring force of the suspension spring 20 buffers an impact during compression, and the compression side damping force controls the compression speed of the suspension spring 20.

  When the hydraulic shock absorber 100 is compressed, oil corresponding to the volume of the piston rod 15 entering the inner cylinder 12 is discharged from the piston rod side oil chamber 41 </ b> A through the oil passage 50 of the inner cylinder 12 to the oil reservoir chamber 43.

(Extension process)
When the hydraulic shock absorber 100 is extended, the outer cylinder 11, the inner cylinder 12 and the piston rod 15 are relatively extended, and the suspension spring 20 is extended. Further, the piston rod 15 retreats from the inner cylinder 12, and the oil in the piston rod side oil chamber 41A moves the disk valve 34 and the annular valve 35 of the pressure increase common oil passage 42 of the piston 32 downward to move the piston side oil chamber. It flows to 41B.

  When the hydraulic shock absorber 100 is fully extended, the rebound spring 63 backed up and supported by the collar 61 fixed to the inner cylinder 12 is compressed by the stopper collar 31 of the piston 32 to restrict the maximum extension stroke.

  When the hydraulic shock absorber 100 is extended, the oil corresponding to the withdrawal volume of the piston rod 15 from the inner cylinder 12 is replenished from the oil reservoir chamber 43 through the oil passage 50 of the inner cylinder 12 to the piston rod side oil chamber 41A. The piston 32 passes through the pressure common oil passage 42 of the piston 32 and is replenished to the piston-side oil chamber 41B.

(Hydraulic shock absorber 200) (FIGS. 7 to 10)
The only difference between the hydraulic shock absorber 200 and the hydraulic shock absorber 100 is that the compression side piston / valve assembly 101A in the hydraulic shock absorber 100 is replaced with an expansion side piston / valve assembly 201A, as shown in FIGS. .

  That is, the hydraulic shock absorber 200 has the above-described extension-side piston / valve assembly 201 </ b> A in order to suppress the expansion and contraction vibration of the suspension spring 20.

  As shown in FIGS. 7 to 9, the extension side piston / valve assembly 201A provided at the tip of the piston rod 15 inserted into the inner cylinder 12 is the same as the aforementioned pressure side piston / valve assembly 101A. Was installed in reverse.

  The extension-side piston / valve assembly 201A has a valve stopper 37, a valve spring 36, an annular valve 35, and a disc valve 34 that are the same as the components of the compression-side piston / valve assembly 101A at the small diameter portion of the piston rod 15. The washer 33 and the piston 32 are inserted in this order, and are held by the caulking portion 38.

  The piston 32 includes a piston ring that slidably contacts the inner circumference of the inner cylinder 12, and the piston rod side oil chamber 41 </ b> A on the side where the piston rod 15 is inserted and the piston rod 15 are inserted inside the inner cylinder 12. It has a pressure expansion common oil passage 42 that is divided into a piston-side oil chamber 41B on the non-piston side and communicates the piston rod-side oil chamber 41A and the piston-side oil chamber 41B. The washer 33, the disk valve 34, and the annular valve 35 are slid on the inner periphery of the guide 37A of the valve stopper 37, and are provided so as to be axially movable with respect to the opening at the upper end of the pressure increasing common oil passage 42. Only the extension side damping force is generated.

  The annular valve 35 (FIG. 5A) includes a plurality of hole-shaped openings 35A, and slides the inner periphery of the guide 37A of the valve stopper 37 so that it is more than the pressure increasing common oil passage 42 on the upper end surface of the piston 32. The oil passage 42 is opened and closed by contacting and separating from the valve seat 32A formed on the outer peripheral side. The valve spring 36 biases the annular valve 35 toward the valve seat 32A. The disc valve 34 (FIG. 5B) is adjacent to the piston 32 side of the annular valve 35 around the guide 37A of the valve stopper 37, and between the upper end surface of the piston 32 and the washer 33 and the annular valve 35. The outer periphery is sandwiched between the valve seat 32A of the piston 32 and closer to the common pressure oil passage 42 than the valve seat 32A, and the outer periphery is bent so as to be in contact with and separated from the annular valve 35 with the inner periphery being cantilevered. It deform | transforms and opens and closes the hole-shaped opening part 35A of the annular valve 35.

  The annular valve 35 and the disc valve 34 constitute an extension side valve assembly 201B.

  Accordingly, in the extension side piston / valve assembly 201A, when extended, the hydraulic pressure of the piston rod side oil chamber 41A is transferred from the hole-shaped opening 35A of the annular valve 35 to the disc valve 34 as shown in FIG. In addition, the disk valve 34 is flexibly deformed (in other words, an expansion-side damping force is generated), so that the oil in the piston rod-side oil chamber 41A flows into the piston-side oil chamber 41B via the pressure-extended common oil passage 42. During compression, as shown in FIG. 10B, the oil pressure in the piston side oil chamber 41B is applied to the disc valve 34 and the annular valve 35, and the disc valve 34 and the annular valve 35 are resisted against the urging force of the valve spring 36. The oil in the piston-side oil chamber 41B is caused to flow through the oil passage 42 to the piston rod-side oil chamber 41A through a path that bypasses the disk valve 34 that is the valve means for generating the extension-side damping force.

  The piston 32 includes two small-diameter hole orifices 32B on the circumference of the valve seat 32A for communicating the pressure increase common oil passage 42 to the piston rod side oil chamber 41A.

  The hydraulic shock absorber 200 is provided with a lower oil reservoir chamber 43 and an upper gas chamber 44 in an annular space between the outer cylinder 11 and the inner cylinder 12, and the piston-side oil chamber 41B is always open to the oil reservoir chamber 43. An oil passage 70 for volume compensation of the piston rod 15 is provided in the inner cylinder 12. Since this oil passage 70 does not generate a damping force during compression, it is only necessary to consider replenishment of hydraulic oil during expansion. Therefore, a sufficiently large opening can be set.

Accordingly, the hydraulic shock absorber 200 operates as follows.
(Compression process)
During compression of the hydraulic shock absorber 200, the outer cylinder 11, the inner cylinder 12, and the piston rod 15 are relatively compressed, and the suspension spring 20 is compressed. Further, the piston rod 15 enters the inner cylinder 12, and the oil in the piston side oil chamber 41B moves the disk valve 34 and the annular valve 35 of the pressure increase common oil passage 42 of the piston 32 upward to move the piston rod side oil chamber. It flows to 41A.

  When the hydraulic shock absorber 200 is compressed, the oil corresponding to the volume of the piston rod 15 entering the inner cylinder 12 is discharged from the piston-side oil chamber 41 </ b> B through the oil passage 70 of the inner cylinder 12 to the oil reservoir chamber 43.

(Extension process)
When the hydraulic shock absorber 200 is extended, the outer cylinder 11, the inner cylinder 12 and the piston rod 15 are relatively extended, and the suspension spring 20 is extended. Further, the piston rod 15 retreats from the inner cylinder 12, and the oil in the piston rod side oil chamber 41A flows into the piston side oil chamber 41B through the orifice 32B of the piston 32 at a low speed, and is extended by the restriction resistance of the orifice 32B during this time. Get side damping force. Further, at medium and high speeds, the oil in the piston rod side oil chamber 41A deflects and deforms the disk valve 34 of the pressure expansion common oil passage 42 of the piston 32 and flows into the piston side oil chamber 41B. Get extension side damping force. The extension side damping force prevents the suspension spring 20 from resonating.

  When the hydraulic shock absorber 200 is fully extended, the rebound spring 71 backed up by the rod guide 14 on the inner cylinder 12 side is compressed by the valve stopper 37 of the piston 32 to restrict the maximum extension stroke.

  When the hydraulic shock absorber 200 is extended, oil corresponding to the withdrawal volume of the piston rod 15 from the inner cylinder 12 is supplied from the oil reservoir 43 through the oil passage 70 of the inner cylinder 12 to the piston-side oil chamber 41B.

  Therefore, in the hydraulic shock absorber 1, the compression side piston / valve assembly 101A of the hydraulic shock absorber 100 generates a compression side damping force during the compression stroke, and the expansion side piston / valve assembly 201A of the hydraulic shock absorber 200 during the expansion stroke. The expansion and contraction vibration of the suspension spring 20 is suppressed by the extension side damping force generated.

  In the compression side piston / valve assembly 101A (the same applies to the expansion side piston / valve assembly 201A), the set of the disk valve 34 and the annular valve 35 is placed on the annular valve 300 shown in FIG. It can be replaced. The annular valve 300 has a hole orifice 301. The annular valve 300 has the same inner and outer diameters as the annular valve 35, is urged toward the valve seat 32 </ b> A of the piston 32 by the valve spring 36, and can slide the guide 37 </ b> A of the valve stopper 37. It is provided so that it can move in the axial direction with respect to the opening. In the compression side valve assembly 101B, the oil in the piston side oil chamber 41B at the time of compression is passed through the orifice 301 and flows from the oil passage 42 of the piston 32 to the piston rod side oil chamber 41A, and the compression side damping force based on the restriction resistance of the orifice 301 is applied. The annular valve 300 is moved downward by the hydraulic pressure of the piston rod side oil chamber 41A during expansion and flows to the piston side oil chamber 41B. In the extension side piston / valve assembly 201A, the oil in the piston rod side oil chamber 41A at the time of extension passes through the orifice 301, and flows from the oil passage 42 of the piston to the piston side oil chamber 41B. A damping force is generated, and the annular valve 300 is moved upward by the hydraulic pressure of the piston-side oil chamber 14B during compression to flow into the piston rod-side oil chamber 41A.

According to the present embodiment, the following operational effects can be obtained.
(a) (1) When the hydraulic shock absorber 100 on one side is compressed, hydraulic oil corresponding to the cross-sectional area of the piston 32 (including the cross-sectional area of the piston rod 15) passes through the disk valve 34 of the piston 32 and passes through the piston 32. The disc valve 34 generates a compression side damping force. As a result, even if the compression side base valve device is eliminated, the compression side damping force will not be insufficient.

  (2) The compression side base valve device was abolished, and the compression damping force was generated by the piston 32. As a result, the annular cross-sectional area of the piston 32 (the cross-sectional area obtained by subtracting the cross-sectional area of the piston rod 15 from the cross-sectional area of the piston 32) is usually larger than the cross-sectional area of the piston rod 15, so Even if the differential pressure of 41B is reduced, the same or more compression side damping force can be generated. Therefore, the pressure in the piston side oil chamber 41B does not become excessive.

  (3) Since the opening of the volume compensation oil passage 50 provided in the piston rod side oil chamber 41A is provided at a position that always opens in the oil reservoir chamber 43, the gas chamber 44 is positioned on the outer periphery of the piston rod side oil chamber 41A. Even in the multi-cylinder hydraulic shock absorber 100 to be performed, the operation of the piston 32 is not hindered, and the air in the gas chamber 44 is not caught in the inner cylinder 12.

  (4) The hydraulic shock absorber 200 on the other side does not generate a compression side damping force at all or substantially, and therefore does not require a compression side base valve device.

  (5) Therefore, both the hydraulic shock absorbers 100 and 200 on the one side and the other side can eliminate the pressure side base valve device. As a result, it is possible to provide a suspension device that can reduce costs and that does not cause excessive pressure in the piston-side oil chamber 41B.

  (b) “A piston valve assembly 101A that generates substantially only a pressure-side damping force is provided at the tip of the piston rod 15 slidably inserted into the inner cylinder 12, and the piston rod-side oil chamber 41A includes The oil passage 50 for volume compensation of the piston rod 15 that always opens in the oil reservoir 43 is provided. ”From the above, the same effect as that of a of claim 1 can be obtained.

  (c) “By providing the opening of the oil passage 50 for volume compensation under the oil surface of the oil reservoir 43 and positioning the extended position of the piston rod 15 below the opening of the oil passage 50, The passage 50 was always opened to the oil reservoir 43. Therefore, even in the double cylinder type hydraulic shock absorber 100 in which the gas chamber 44 is located on the outer periphery of the piston rod side oil chamber 41A, the air in the gas chamber 44 is Is not caught in the inner cylinder 12.

  (d) “By providing the extended position regulating member 60 of the piston rod 15 between the inner cylinder 12 side and the piston rod 15 side, the oil passage 50 for volume compensation is always opened in the oil reservoir chamber 43. ”, The volume compensation oil passage 50 can always be opened in the oil reservoir chamber 43 by the extended position restricting member 60.

  (e) “The extended position restricting member 60 is formed of a cylindrical collar 61 fixed to the inner periphery of the upper portion of the inner cylinder 12, and between the tip end portion of the collar 61 and the piston rod 15, The coil spring 62 is interposed, so that the cylindrical collar 61 is fixed to the inner periphery of the upper portion of the inner cylinder 12, so that the extended position restricting member 60 of the piston rod 15 is obtained. With this configuration, the opening of the volume compensating oil passage 50 can be positioned below the oil level.

  Since the coil spring 62 is used as a buffer means at the time of maximum extension, even when the coil spring 62 is attached to the inner cylinder 12 side, there is a gap between the lines, so that the volume compensating oil passage 50 (opening) is blocked. There is nothing.

  (f) “A piston valve assembly 201A that generates a damping force substantially only when extended is provided at the tip of the piston rod 15 slidably inserted into the inner cylinder 12, and an oil reservoir is provided in the piston-side oil chamber 41B. Since the oil passage 70 for volume compensation of the piston rod 15 that is always open in the chamber 43 is provided. ", The hydraulic shock absorber 200 does not generate a compression side damping force at all or substantially, and therefore the compression side base valve device. Can be abolished. Therefore, the cost can be reduced and the pressure in the piston-side oil chamber 41B does not become excessive.

  In the hydraulic shock absorber 100 on one side of the present embodiment, “always opening” the volume compensation oil passage 50 of the piston rod 15 is not blocked by the piston even at the maximum extension, It means opening directly to the oil reservoir without going through the gas chamber. This is because when the gas chamber is opened, the air in the gas chamber is sucked when the gas chamber is extended.

  In addition, the opening of the oil passage 70 for volume compensation of the piston rod 15 in the hydraulic shock absorber 200 on the other side of the present invention does not need to generate a compression-side damping force at this opening. The size can be set taking into consideration only the suction property.

  Further, the vehicle to which the present invention is applied is a four-wheeled vehicle, regardless of a motorcycle, as long as the outer cylinder side of the hydraulic shock absorber is attached to a common axle or an axle-side member having a common axle. May be. That is, it is sufficient if the left and right hydraulic shock absorbers are interlocked in synchronization with the left and right.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

FIG. 1 is an overall view showing a hydraulic shock absorber of a vehicle. FIG. 2 is a cross-sectional view showing one of the left and right hydraulic shock absorbers. FIG. 3 is an enlarged view of a main part of FIG. 4A and 4B show a piston / valve assembly, in which FIG. 4A is an overall cross-sectional view and FIG. 5A and 5B show components of the piston / valve assembly, in which FIG. 5A is a plan view showing an annular valve, FIG. 5B is a sectional view showing a disc valve, and FIG. 5C is a plan view showing a modification of the annular valve. is there. 6A and 6B show the operating state of the piston and valve assembly, where FIG. 6A is a cross-sectional view showing a compressed state, and FIG. 6B is a cross-sectional view showing an extended state. FIG. 7 is a cross-sectional view showing the left and right hydraulic shock absorbers. FIG. 8 is an enlarged view of a main part of FIG. 9A and 9B show a piston / valve assembly, where FIG. 9A is an overall cross-sectional view and FIG. 10A and 10B show the operating state of the piston and valve assembly, where FIG. 10A is a cross-sectional view showing an expanded state, and FIG. 10B is a cross-sectional view showing a compressed state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic shock absorber 11 Outer cylinder 12 Inner cylinder 14 Rod guide 15 Piston rod 41A Piston rod side oil chamber 41B Piston side oil chamber 42 Pressure expansion common oil passage 43 Oil reservoir chamber 44 Gas chamber 50 Oil passage 60 for volume compensation Position regulating member 61 Collar 63 Rebound spring (coil spring)
70 Oil passages 100, 200 for volume compensation Hydraulic shock absorber 101A Piston / valve assembly 201A Piston / valve assembly

Claims (6)

Install hydraulic shock absorbers on the left and right of the wheel
In the vehicle hydraulic shock absorber, in which only the compression side damping force is substantially generated in the one side hydraulic shock absorber, and only the expansion side damping force is substantially generated in the other side hydraulic shock absorber,
The hydraulic shock absorber on one side is
At the bottom of the outer cylinder, set up the inner cylinder,
A piston / valve assembly that substantially generates only a compression-side damping force is provided at the tip of a piston rod slidably inserted into the inner cylinder through a rod guide provided in the opening of the inner cylinder. ,
In the inner cylinder, a piston rod side oil chamber that accommodates the piston rod and a piston side oil chamber that does not accommodate the piston rod are partitioned,
While sealing between the opening of the outer cylinder and the piston rod, a lower oil reservoir and an upper gas chamber are provided between the inner cylinder and the outer cylinder,
The piston rod side oil chamber is provided with an oil passage for volume compensation of the piston rod that is always open to the oil reservoir chamber,
The hydraulic shock absorber on the other side is
At the bottom of the outer cylinder, set up the inner cylinder,
A piston / valve assembly that generates substantially only an extension-side damping force at the tip of a piston rod slidably inserted into the inner cylinder through a rod guide provided in the opening of the inner cylinder. Provided,
In the inner cylinder, a piston rod side oil chamber that accommodates the piston rod and a piston side oil chamber that does not accommodate the piston rod are partitioned,
Sealing between the opening of the outer cylinder and the piston rod, and providing a lower oil reservoir and an upper gas chamber between the inner cylinder and the outer cylinder,
The piston-side oil chamber is provided with an oil passage for volume compensation of the piston rod that always opens to the oil reservoir chamber.
A hydraulic shock absorber for a vehicle. At the bottom of the outer cylinder, set up the inner cylinder,
A piston / valve assembly that substantially generates only a compression-side damping force is provided at the tip of a piston rod slidably inserted into the inner cylinder via a rod guide provided in the opening of the inner cylinder.
In the inner cylinder, a piston rod side oil chamber that accommodates the piston rod and a piston side oil chamber that does not accommodate the piston rod are partitioned,
Sealing between the opening of the outer cylinder and the piston rod, and providing a lower oil reservoir and an upper gas chamber between the inner cylinder and the outer cylinder,
A hydraulic shock absorber for a vehicle, characterized in that an oil passage for volume compensation of the piston rod that always opens to the oil reservoir chamber is provided in the oil chamber on the piston rod side.   An opening of the oil passage for volume compensation is provided below the oil surface of the oil reservoir chamber, and the extended position of the piston rod is positioned below the opening of the oil passage, whereby the oil passage is The vehicle hydraulic shock absorber according to claim 2, wherein the oil reservoir chamber is always opened.   4. The volume compensation oil passage is always opened in the oil reservoir chamber by providing an extension position regulating member for the piston rod between the inner cylinder side and the piston rod side. The vehicle hydraulic shock absorber as described in 1.   The fully extended position restricting member is formed of a cylindrical collar fixed to the inner periphery of the upper part of the inner cylinder, and a coil spring is provided between the leading end of the collar and the piston rod to provide a buffer during maximum extension. The vehicle hydraulic shock absorber according to any one of claims 2 to 4. At the bottom of the outer cylinder, set up the inner cylinder,
A piston / valve assembly that substantially generates only an extension-side damping force is provided at the tip of a piston rod slidably inserted into the inner cylinder through a rod guide provided in the opening of the inner cylinder. Provided,
In the inner cylinder, a piston rod side oil chamber that accommodates the piston rod and a piston side oil chamber that does not accommodate the piston rod are partitioned,
While sealing between the opening of the outer cylinder and the piston rod, a lower oil reservoir and an upper gas chamber are provided between the inner cylinder and the outer cylinder,
A hydraulic shock absorber for a vehicle, wherein the piston-side oil chamber is provided with an oil passage for volume compensation of the piston rod that is always open to the oil reservoir chamber.

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