JP2015117737A - Pressure buffer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure buffer device which can make an attenuation force variable, does not generate the seizure of a pressing member for pressing a valve, and can stably and highly-reliably adjust the attenuation force.SOLUTION: A hydraulic pressure buffer device 1 which generates an attenuation force by controlling a flow of fluid comprises: an elongation-side flow passage 622 in which the fluid flows; a first attenuation valve 63 which opens and closes the elongation-side flow passage 622 according a flow of the fluid; a pressing member 78 which is arranged so as to be capable of pressing the first attenuation valve 63 to a direction in which the first attenuation valve 63 is closed; a guide part 792 which movably guides the pressing member 78; and energization means which variably energizes the pressing force for pressing the first attenuation valve 63 to a closing direction to the pressing member 78. The pressing member 78 contacts with the guide part 792 substantially vertically to a moving direction of the pressing member 78.

Description

  The present invention relates to a pressure buffering device.

  Conventionally, a pressure buffering device that generates a damping force by controlling a flow of a fluid is known. For example, in Patent Document 1, the piston portion is formed with a second flow path that communicates between two oil chambers in which the cylinder is divided into two, and a damping valve that closes or opens the opening of the second flow path. And a partition formed between a pressing member that moves in the axial direction to press the damping valve and closes the opening of the second flow path, and a piston rod that is movable in the axial direction inside the cylinder, It has an orifice that can communicate with the first flow path formed in the piston rod portion and can communicate with one of the oil chambers, and has a space portion that moves in the axial direction by pressing the pressing member with internal pressure. A pressure buffer device is disclosed in which the opening area of the opening of the first flow path is changed by the rod portion, thereby adjusting the flow rate of oil flowing into the space portion and adjusting the pressing force with which the pressing member presses the damping valve. ing.

  Further, in Patent Document 2, in a piston valve device of a hydraulic shock absorber, a valve seat having a diameter smaller than the diameter of the disc valve is provided on the back surface of the disc valve that contacts the piston, and the diameter of the valve seat is provided on the back surface of the valve seat. A ball retainer with a large diameter is arranged, and a ball having a diameter larger than the sum of the plate thickness of the ball retainer and the valve seat is held in each of the ball holding holes provided at a plurality of positions in the circumferential direction of the ball retainer. A configuration is disclosed in which a ball is pressed against a back surface of a disc valve by pressing a ball with a valve spring disposed on the back surface.

JP 2007-177822 A JP 2008-274991 A

  In the technique disclosed in Patent Document 1, so-called “galling” that locks in the space when the pressing member tilts may occur. If this pressing member is locked in the space, the damping force may be fixed because the damping force is high, or may be adjusted while the damping force is low. .

  On the other hand, in the disclosed technique of Patent Document 2, the ball is supported in the cylinder axial direction by the disk valve and the valve spring, and is supported in the direction perpendicular to the cylinder axial direction by the ball retainer. For this reason, even if a load is applied to the ball, the ball is not in a freely movable state, and does not cause “galling” by the ball in the first place, and variation in damping force hardly occurs. However, since the pressing force with which the ball presses the disc valve is maintained at a preset force, the damping force characteristic is also maintained at a preset value. That is, with the disclosed technique of Patent Document 2, for example, it is impossible to adjust the damping force so that the damping force is varied while the vehicle is actually running with the pressure buffering device assembled to the vehicle body or the like.

  Therefore, the present invention has been devised in view of the above-described problems, and an object of the present invention is to make the damping force variable and stable without causing galling of the pressing member that presses the valve. An object of the present invention is to provide a pressure buffer device capable of adjusting the damping force with high reliability.

  A pressure buffer device according to a first aspect of the present invention is a pressure buffer device that generates a damping force by controlling a flow of a fluid, a flow path through which the fluid flows, a valve that opens and closes the flow path according to the flow of the fluid, A pressing member provided so as to be capable of pressing the valve in a direction in which the valve is closed, a guide portion for guiding the pressing member so as to be movable, and a biasing force that variably presses the pressing member in the direction in which the valve is closed And the pressing member is in contact with the guide portion substantially perpendicular to the moving direction of the pressing member.

  The pressure buffering device according to a second aspect of the present invention is characterized in that, in the first aspect, the guide portion includes two or more holes.

  According to a third aspect of the present invention, in the first or second aspect, the urging means is the pressure of the fluid in the guide portion.

  The pressure buffering device according to a fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, the guide portion is provided in a direction substantially perpendicular to the valve.

  The pressure buffering device according to a fifth aspect of the present invention is characterized in that, in any one of the first to third aspects, the guide portion is provided to be inclined with respect to the valve.

  A pressure buffering device according to a sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the pressing member is formed at least on the surface by a resin.

  The pressure buffering device according to a seventh aspect of the present invention is characterized in that, in any one of the first to sixth aspects, the pressing member is formed in a substantially spherical shape.

  According to the first invention, a valve that opens and closes the flow path according to the flow of the fluid, a pressing member that is provided so as to be able to press the valve in a direction in which the valve is closed, and a guide portion that guides the pressing member to be movable, The pressing member is configured to contact the guide portion substantially perpendicular to the moving direction of the pressing member. For this reason, the so-called galling that the pressing member is caught on the guide portion is less likely to occur, and the variable damping force can be realized with high reliability. Further, according to the first invention, since the pressing member is configured to contact the guide portion substantially perpendicular to the moving direction of the pressing member, for example, it is not necessary to excessively increase the processing accuracy, so that the processing becomes easy and the manufacturing cost is increased. Can be kept low. Furthermore, in the first invention, the damping force can be adjusted only by increasing / decreasing the number of the pressing members and the guide portions, so that the setting of the damping force of the pressure buffer device is facilitated.

  According to the second aspect of the invention, since the guide portion has two or more holes, the pressure receiving area for pushing the valve from the valve closing side of the valve is smaller than that of the continuous annular shape in the plan view. can do. As a result, regardless of the size of the pressure receiving area on the valve opening side of the valve, the pressure receiving area on the valve closing side can be changed by increasing or decreasing the number of holes in the guide portion, thereby The pushing force from the valve closing side can be adjusted in accordance with the size of the pressure receiving area.

  According to the third invention, since the pressing force can be applied to the pressing member using the fluid, the damping force characteristic can be continuously varied by adjusting the liquid pressure.

  According to the fourth aspect of the present invention, since the guide portion is provided in a direction substantially perpendicular to the valve, it is possible to facilitate processing when forming the guide portion.

  According to the fifth invention, since the guide portion is provided to be inclined with respect to the valve, the pressing force for pressing the valve by the pressing member can be increased, and the damping force per pressing member is improved. be able to. Further, according to the fifth aspect, since the guide portion is inclined with respect to the valve, the pressing member is always in contact with the inner wall of the guide portion, and the size of the gap between the guide portion and the pressing member is maintained and stabilized. To do. For this reason, since the amount of oil leakage in the gap between the guide portion and the pressing member is stabilized, the damping force is stabilized, and the setting for adjusting the damping force is facilitated.

  According to the sixth invention, since at least the surface of the pressing member is formed of resin, the resin around the pressing member is sandwiched in the axial direction of the guide portion by the valve and oil. Is deformed so as to spread in the radial direction of the guide portion. As a result, a clearance (gap) between the guide portion and the pressing member is filled to improve the sealing performance, and the amount of fluid leakage in the guide portion is suppressed. As a result, the pressure in the guide portion can be increased more easily, and for example, the valve closing pressure for the valve can be increased.

  According to the seventh invention, since the pressing member is formed in a substantially spherical shape, for example, a general-purpose product such as a ball of a bearing can be used, and the manufacturing cost can be kept low.

It is the vertical front view which showed schematic structure of the hydraulic shock absorber of 1st Embodiment. FIG. 2 is a side view of the hydraulic shock absorber partially enlarged as viewed from an arrow II shown in FIG. 1. FIG. 3 is a cross-sectional plan view taken along line III-III of the hydraulic shock absorber shown in FIG. 2. It is a figure for demonstrating in detail the damping force adjustment mechanism shown in FIG. (A) is a top view of the valve | bulb pressing part in the hydraulic shock absorber of 1st Embodiment, (b) is sectional drawing of the Vb-Vb line | wire shown to (a). (A) is a figure which shows the flow of the oil of the damping force adjustment mechanism at the time of a pressure stroke, (b) is a figure which shows the oil flow of the damping force adjustment mechanism at the time of an extension stroke. (A) is a figure which shows the case where all the positions of a pressing member and an extension side flow path overlap, (b) is a figure which shows the case where the position of a pressing member and an extension side flow path overlaps only partially. FIG. 8C is a diagram illustrating a case where the pressing member and the extension-side flow path are arranged on different circumferences at different distances from the center of the housing in plan view. (A)-(c) is a figure for demonstrating the pressing member of another Example. (A) is a top view of the valve | bulb pressing part in the hydraulic shock absorber of 2nd Embodiment, (b) is sectional drawing of the IXb-IXb line | wire shown to (a), (c) is (a). It is a figure for demonstrating the effect | action of the force in the pressing member and guide part to show. (A) And (b) is a figure for demonstrating the clearance of a guide part and a pressing member. It is a figure for demonstrating the pressing member and guide part in the hydraulic shock absorber of 3rd Embodiment. It is a figure for demonstrating the pressing member and guide part in the hydraulic shock absorber of 4th Embodiment. It is a figure for demonstrating the valve | bulb pressing part in the hydraulic shock absorber of 5th Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>

  FIG. 1 is a longitudinal front view showing a schematic configuration of a hydraulic shock absorber 1 according to a first embodiment. FIG. 2 is a side view of the hydraulic shock absorber 1 partially enlarged as seen from the arrow II shown in FIG.

<Configuration and function of hydraulic shock absorber 1>

  The hydraulic shock absorber 1 is provided as a suspension on a vehicle body such as a two-wheel or four-wheel vehicle (not shown). As shown in FIG. 1, the hydraulic shock absorber 1 includes a cylinder portion 10 and a piston rod portion in which one end is extended to the outside of the cylinder portion 10 and the other end is slidably fitted inside the cylinder portion 10. 20 and a spring portion 30 disposed so as to cover the cylinder portion 10 and the piston rod portion 20 from the outside. The hydraulic shock absorber 1 further includes a sub tank 40 and a damping force adjusting mechanism 50 as shown in FIG. The hydraulic shock absorber 1 of the present embodiment is provided, for example, between a vehicle body and a rear wheel in a motorcycle or the like, and supports the weight of the vehicle body and absorbs and attenuates shocks. In the following description, the lower side of FIG. 1 in the axial direction of the hydraulic shock absorber 1 shown in FIG. 1 is referred to as “axle side”, and the upper side of FIG. 1 in the axial direction is referred to as “vehicle body side”.

(Configuration and function of cylinder part 10)

  As shown in FIG. 1, the cylinder portion 10 is provided inside the outer cylinder 11 with a hollow outer cylinder 11 whose end on the axle side is open and whose end on the vehicle body is closed, and both ends are open. The hollow inner cylinder 12 is formed, and the outer cylinder 11 and the rod guide 13 disposed at the end of the inner cylinder 12 on the axle side are provided.

  The outer cylinder 11 is a member formed in a substantially cylindrical shape. The outer cylinder 11 is closed at the axle end of the outer cylinder 11 by attaching the rod guide 13 to the opened end of the axle. The outer cylinder 11 is closed by providing an end portion 11B on the vehicle body side.

  The end portion 11B has oil between an oil passage 111 that communicates oil with a first oil chamber 50A (described later) of the damping force adjusting mechanism 50 and a second oil chamber 50C (described later) of the damping force adjusting mechanism 50. And an oil passage 112 communicating with each other.

  The outer cylinder 11 includes a vehicle body side connecting portion 113 that is connected to the vehicle body, and a spring adjusting portion 114 that is formed on the vehicle body side.

  The vehicle body side connecting portion 113 includes a through hole 113H for connecting the vehicle body such as a motorcycle (not shown) and the hydraulic shock absorber 1 to each other. And the hydraulic shock absorber 1 is assembled | attached to vehicle bodies, such as a two-wheeled vehicle, by attaching the vehicle body side connection part 113 to a vehicle body.

  The spring adjustment unit 114 is a male screw formed on the outer periphery of the outer cylinder 11. The spring adjuster 114 is attached with a spring receiver 33 and a lock nut 34 which will be described later. The spring adjusting unit 114 is configured to move the spring receiver 33 and the lock nut 34 in the axial direction, and holds the spring receiver 33 and the lock nut 34.

  The inner cylinder 12 is formed in a substantially cylindrical shape and is provided inside the outer cylinder 11. The outer diameter of the inner cylinder 12 is smaller than the inner diameter of the outer cylinder 11. An oil passage 12 </ b> L is formed by a gap between the inner cylinder 12 and the outer cylinder 11. The oil passage 12L communicates the inside of the inner cylinder 12 with the damping force adjusting mechanism 50 and enables oil flow.

  Further, the inner cylinder 12 includes an opening 12H that is opened in a direction substantially orthogonal to the axial direction in the vicinity of the end on the axle side. The opening 12H allows oil to flow between the inner cylinder 12 and the oil passage 12L.

  The end of the inner cylinder 12 on the vehicle body side is abutted against the end 11B of the outer cylinder 11 and closed. The end of the inner cylinder 12 on the axle side is closed by a rod guide 13. The inner cylinder 12 accommodates fluid and is filled with oil in this embodiment. Then, a later-described piston 22 and part of the rod member 21 of the piston rod portion 20 are inserted into the inner cylinder 12.

  The rod guide 13 is a substantially cylindrical member having a hole 13H penetrating substantially at the center in the radial direction. A rod member 21 to be described later is inserted into the through hole 13H. A first seal member 13S is attached between the rod guide 13 and the outer cylinder 11 to prevent oil from flowing out at the end. A bush 13B is provided on the inner periphery of the through hole 13H, and supports the rod member 21 so as to be slidable in the cylinder axial direction. Furthermore, the rod guide 13 includes a second seal member 13 </ b> G between the rod guide 21 and the rod guide 21. The second seal member 13 </ b> G seals between the outer periphery of the rod member 21 and the inner periphery of the rod guide 13.

(Configuration and function of piston rod 20)

  The piston rod portion 20 includes a rod member 21, a piston 22 provided on the vehicle body side of the rod member 21, and a rebound spring 23 disposed on the axle side of the piston 22.

  The rod member 21 is, for example, a solid rod-shaped member. Then, by being slidably supported by the rod guide 13, a part is inserted inside the inner cylinder 12, and a part protrudes or enters from the inner cylinder 12. Further, the rod member 21 includes an axle side connecting portion 211 at an end portion on the axle side. The axle side connecting portion 211 includes a through hole 211H for connecting an axle of a two-wheeled vehicle and the hydraulic shock absorber 1, for example. The rod member 21 may be a rod-shaped member formed in a hollow shape.

  The piston 22 includes a piston member 221 movably provided inside the inner cylinder 12, a piston ring 222 disposed between the outer periphery of the piston member 221 and the inner periphery of the inner cylinder 12, and the body of the piston member 221. And a piston nut 223 provided on the side.

  The piston member 221 is a member formed in a substantially disk shape, and has an outer diameter smaller than the inner diameter of the inner cylinder 12. The piston ring 222 is provided on the outer periphery of the piston member 221. The piston ring 222 allows the piston member 221 to slide in the axial direction of the inner cylinder 12 while sealing between the piston member 221 and the inner cylinder 12. The piston nut 223 is screwed to the end of the rod member 21 to fix the piston member 221 to the end of the rod member 21.

  The piston 22 defines an oil storage chamber in the inner cylinder 12 to form a piston-side oil chamber 12A on the side (vehicle body side) on which the rod member 21 does not protrude, as shown in FIG. The piston rod side oil chamber 12B is formed on the side from which the member 21 protrudes (axle side).

  The rebound spring 23 is attached so as to be sandwiched between the piston 22 and the rod guide 13. And the rebound spring 23 relieves | impacts the impact at the time of the piston 22 trying to contact the rod guide 13 when the rod member 21 extends most in the extension side stroke in the hydraulic shock absorber 1, for example.

  The spring portion 30 includes a suspension spring 31, a spring receiver 32 disposed on the axle side of the suspension spring 31, a spring receiver 33 disposed on the vehicle body side of the suspension spring 31, a lock nut 34, and a bump rubber 35.

  The suspension spring 31 has an axle side held by a spring receiver 32 and a vehicle body side held by a spring receiver 33. The impact force that the vehicle receives from the road surface is absorbed by the elastic force of the suspension spring 31. The spring receiver 32 is attached to the axle side connecting portion 211. The spring receiver 32 supports the axle side of the suspension spring 31. The spring receiver 33 is screwed to the spring adjusting portion 114 of the outer cylinder 11. The lock nut 34 is positioned outside the spring receiver 33 in the axial direction and is screwed to the spring adjustment unit 114. The lock nut 34 fixes the spring receiver 33 in the axial direction against the repulsive force of the suspension spring 31.

  In the present embodiment, the bump rubber 35 contacts the rod guide 13 when the hydraulic shock absorber 1 is in the most compressed state in the cylinder axis direction, and the axle side of the rod guide 13 collides with the axle side connecting portion 211. Absorbs the impact.

  3 is a cross-sectional plan view taken along line III-III of the hydraulic shock absorber 1 shown in FIG. In the following description, the left side of the sub tank 40 and the damping force adjusting mechanism 50 shown in FIG. 3 is referred to as “one side”, and the right side of the drawing is referred to as “the other side”.

(Configuration and function of sub tank 40)

  The sub tank 40 is provided in the vicinity of the vehicle body side end of the outer cylinder 11 (see FIG. 2). As shown in FIG. 3, the sub-tank 40 has a hollow, substantially cylindrical shape, one of which is open and the other is closed, a bladder 42 provided inside the space forming part 41, and one side And a cap 43 provided at the end of the head.

  The space formation part 41 forms the space which accommodates gas and oil inside. The space forming portion 41 accommodates the bladder 42 inside the hollow and is sealed by providing a cap 43 in the opening 41H. Further, the space forming portion 41 includes a communication passage 41L through which oil can flow. The communication passage 41L communicates with a first oil chamber 50A (described later) of the damping force adjustment mechanism 50.

  The bladder 42 is a bag-like member that is deformable by using an elastic body such as rubber as a material. The bladder 42 is fitted inside the opening 41H of the space forming portion 41 at the end on the opening 42H side. The opening 42H of the bladder 42 is closed by the cap 43. The gas is sealed inside the bladder 42 to form a gas chamber 42A for containing the gas. The bladder 42 is formed with a smaller capacity than the space forming portion 41. Therefore, as shown in FIG. 3, a sub tank oil chamber 41 </ b> A that stores fluid is formed between the outer periphery of the bladder 42 and the inner periphery of the space forming portion 41. The sub tank oil chamber 41A communicates with a later-described first oil chamber 50A of the damping force adjusting mechanism 50 via the communication passage 41L described above.

  The cap 43 closes the opened end portions of the space forming portion 41 and the bladder 42.

(Configuration and function of damping force adjusting mechanism 50)

  FIG. 4 is a diagram for explaining the damping force adjusting mechanism 50 shown in FIG. 3 in detail.

  As shown in FIG. 2, the damping force adjusting mechanism 50 is disposed in parallel with the sub tank 40 in the vicinity of the end of the hydraulic shock absorber 1 on the vehicle body side in the axial direction. As shown in FIG. 4, the damping force adjusting mechanism 50 includes a space forming member 50 </ b> H having a hollow, substantially cylindrical shape with one end opened and the other end closed. A solenoid portion 75 provided in the vicinity of one end portion of the solenoid portion 75, a back pressure adjusting portion 70 connected to the other end portion of the solenoid portion 75 and extended toward the hollow interior of the space forming member 50H, A valve unit 61 provided on the other side inside the space forming member 50H and having a back pressure adjusting portion 70 penetratingly disposed substantially at the center thereof, a washer 761 provided on the other side of the valve unit 61, and the other side of the washer 761 And a nut 762 provided on the head. Further, the damping force adjusting mechanism 50 includes a first oil chamber 50A surrounded by the valve unit 61 and the back pressure adjusting portion 70 on one side of the valve unit 61 inside the space forming member 50H, and the space forming member 50H. And a second oil chamber 50 </ b> C surrounded by the valve unit 61 and the back pressure adjusting unit 70 on the other side of the valve unit 61.

  In the present embodiment, the space forming member 50H is formed integrally with the sub tank 40 and the end portion 11B of the outer cylinder 11, as shown in FIG. As shown in FIG. 3, the space forming member 50 </ b> H accommodates various members such as the above-described valve unit 61 on the inner side and enables oil to be sealed.

  The first oil chamber 50 </ b> A communicates with the piston-side oil chamber 12 </ b> A (see FIG. 1) of the cylinder portion 10 through the oil passage 111. The first oil chamber 50A communicates with the sub tank oil chamber 41A of the sub tank 40 via the communication path 41L. The second oil chamber 50C communicates with the piston rod side oil chamber 12B (see FIG. 1) via the oil passage 112 and the oil passage 12L.

  As shown in FIG. 4, the solenoid portion 75 includes a hollow solenoid housing 754 provided in the vicinity of one end inside the hollow space forming member 50 </ b> H, and an annular coil 751 provided inside the solenoid housing 754. A plunger 753 provided on the inner periphery of the coil 751, a shaft 752 fixed to a through hole (not shown) of the plunger 753, a bush 756 provided on the outer periphery in the vicinity of the other end of the shaft 752, and a bush And a support member 755 provided on the outer periphery of 756.

  The solenoid housing 754 houses all members of the coil 751, the plunger 753, the shaft 752, and the bush 756. The coil 751 generates a magnetic field when energized. For the plunger 753, for example, a magnetic material can be used. The plunger 753 moves in the axial direction under the action of the magnetic field generated by the coil 751. The shaft 752 moves in the axial direction as the plunger 753 moves. The shaft 752 is disposed at one end of a needle 736 described later. The bush 756 holds the shaft 752 so as to be slidable in the rod axis direction. The support member 755 is provided between the solenoid housing 754 and the bush 756 and supports the other end of each.

  The solenoid 75 generates a magnetic field by energizing the coil 751 and moves the plunger 753 to operate the shaft 752 fixed to the plunger 753, thereby enabling the needle 736 to reciprocate by the shaft 752. The coil 751 is controlled by a control unit (not shown).

  As shown in FIG. 3, the valve unit 61 includes a flow path forming member 62 that forms a flow path of a fluid that generates a damping force, and an end on one side of the flow path forming member 62. A first damping valve 63 that opens and closes the flow path at one end of the flow path forming member 62, a second attenuation valve 64 provided at the other end of the flow path forming member 62, and a flow path The sealing member 65 provided between the formation member 62 and the space formation member 50H is provided.

  The flow path forming member 62 is a member formed in a thick, substantially cylindrical shape, and has an outer diameter substantially equal to the inner periphery of the space forming member 50H. The flow path forming member 62 is provided with a through hole 62R formed in the axial direction so as to pass an oil path forming rod 71 (described later) and a shaft radially outside the through hole 62R. A pressure side channel 621 formed in the direction and an extension side channel 622 formed in the axial direction are formed. Further, the flow path forming member 62 is formed to extend in the radial direction at the end portion on one side, and extends in the radial direction at the end portion on the other side, and an oil passage 623 communicating with the pressure side flow path 621. An oil passage 624 that is formed and communicates with the extension-side passage 622 is formed. The compression-side flow path 621 and the expansion-side flow path 622 are formed in plural numbers (six in the present embodiment) at equal intervals in the circumferential direction, and communicate with the first oil chamber 50A and the second oil chamber 50C. Functions as a communication path.

  The first damping valve 63 is configured, for example, by stacking a plurality of substantially disk-shaped metal plates. In the first damping valve 63, a through hole (not shown) is formed in the approximate center of each metal plate, and an oil passage forming rod 71 (described later) is inserted through the through hole. The first damping valve 63 allows the expansion side flow path 622 to be opened and closed, but always opens the pressure side flow path 621 when the oil path 623 communicates with the first oil chamber 50A.

  The second damping valve 64 is configured by, for example, stacking a plurality of substantially disk-shaped metal plates. In the second damping valve 64, a through hole (not shown) is formed in the approximate center of each metal plate, and an oil passage forming rod 71 (described later) is inserted through the through hole. The second damping valve 64 enables the pressure side flow path 621 to be opened and closed, but always opens the extension side flow path 622 by connecting the oil path 624 to the second oil chamber 50C.

  The seal member 65 seals the gap between the flow path forming member 62 and the space forming member 50H. The seal member 65 seals the gap between the outer periphery of the flow path forming member 62 and the inner periphery of the space forming member 50H, thereby allowing the oil flow between the first oil chamber 50A and the second oil chamber 50C to flow. Stop.

(Configuration / Function of Back Pressure Adjustment Unit 70)

  As shown in FIG. 4, the back pressure adjusting unit 70 is provided on one side of the oil passage forming rod 71 and an oil passage forming rod 71 extending in a direction toward the one side and the other side (hereinafter referred to as the rod axial direction). Provided with a needle portion 73 and a valve pressing portion 79 disposed on one side of the valve unit 61.

  The oil passage forming rod 71 includes a rod portion 71a that is provided on the other side and extends in the rod axial direction, and a step portion 71b that is provided on one side and has a larger outer diameter than the rod portion 71a. Yes. The oil passage forming rod 71 has a stepped portion 71 b supported by the solenoid housing 754.

  In addition, the oil passage forming rod 71 is disposed on the other side in the rod axis direction with the oil passage 711 formed to extend in the rod axis direction on the inner side, and from the inner side to the outer side in the radial direction with respect to the oil passage 711. An oil passage 712 that extends and an oil passage 714 that is formed in the rod axial direction on the outer side in the radial direction than the oil passage 711 are provided.

  The oil passage 711 communicates with the second oil chamber 50C on the other side, and communicates with an oil passage 731 of a needle receiving portion 737 described later on one side. The oil passage 712 is formed from the oil passage 711 toward the oil passage 794 of the collar 791 described later and the oil passage 793 of the housing 790, and enables the oil to flow between the oil passage 711 and a guide portion 792 described later. . The oil passage 714 forms an oil flow between an oil passage 735 and a first oil chamber 50A in a gap between a needle receiving portion 737 and an oil passage forming rod 71 described later.

  The needle portion 73 includes a needle 736 provided on the other side of the shaft 752, a needle receiving portion 737 provided outside the needle 736 in the radial direction, and a spring provided between the needle receiving portion 737 and the needle 736 in the radial direction. 738.

  The needle 736 is operated by the coil 751 and advances and retreats with respect to the oil passage 731 of the needle receiving portion 737. The needle 736 forms a throttle portion 736 </ b> S that restricts the flow of oil between the needle receiving portion 737 and the oil passage 732. Further, as will be described later, the needle 736 changes the pressure of oil in each oil passage of the oil passage 711, the oil passage 712, the oil passage 794, the oil passage 793, and the guide portion 792 depending on the opening degree of the throttle portion 736S. . The needle 736 includes an oil passage 739 and an oil passage 733 formed on one side of the oil passage 739.

  The needle receiving portion 737 is disposed at one end of the oil passage forming rod 71 and is disposed outside the needle 736 in the radial direction. The needle receiving portion 737 includes an oil passage 731 having an inner diameter larger than the outer diameter of the other end portion of the needle 736, an oil passage 732 disposed radially outside the oil passage 731, and the solenoid portion 75. An oil passage 734 formed between the other end portion and an oil passage 735 formed between one end portion of the oil passage forming rod 71 is provided.

  The oil passage 731 communicates the oil passage 711 and the oil passage 739. The oil passage 739 forms a space for accommodating the spring 738 inside the needle receiving portion 737 in the radial direction. The oil passage 739 communicates the oil passage 731 and the oil passage 733. The oil passage 733 communicates the oil passage 739 and the oil passage 734. The oil passage 734 communicates the oil passage 733 and the oil passage 732. The oil passage 732 communicates the oil passage 734 and the oil passage 735. The oil passage 735 communicates the oil passage 732 and the oil passage 714. That is, the oil passage 731, the oil passage 732, the oil passage 733, the oil passage 734, the oil passage 735, and the oil passage 739 enable oil to flow from the oil passage 711 to the oil passage 714. Then, as will be described later, the flow of oil between the first oil chamber 50A and the oil passage 711 with which the oil passage 714 communicates is controlled according to the opening degree of the needle 736 and the oil passage 731.

  The spring 738 biases an elastic force in a direction in which the needle 736 moves away from the needle receiving portion 737. The spring 738 contracts when the needle 736 receives a force in a direction approaching the needle receiving portion 737 by the coil 751.

  The valve pressing portion 79 includes a pressing member 78 disposed on one side of the valve unit 61, a housing 790 that holds the pressing member 78, and a collar 791 that is disposed between the housing 790 and the oil passage forming rod 71. Prepare.

  The pressing member 78 is arranged so that the first damping valve 63 can be pressed. The pressing member 78 is, for example, a metal member. The pressing member 78 is preferably substantially spherical. The pressing member 78 is accommodated in a guide portion 792 described later of the housing 790. Since the pressing member 78 is formed in a substantially spherical shape, the outer diameter of the pressing member 78 does not become larger than the inner diameter of the guide portion 792 even if the pressing member 78 is tilted, so that the pressing member 78 is locked to the guide portion 792. No “galling” occurs. In the first embodiment, for example, five pressing members 78 are provided.

  Fig.5 (a) is a top view of the valve | bulb pressing part 79 in the hydraulic shock absorber 1 of 1st Embodiment, FIG.5 (b) is sectional drawing of the Vb-Vb line | wire shown to Fig.5 (a).

  As shown in FIG. 5A, the housing 790 is formed in a substantially disk shape having an opening 790R. The housing 790 holds the collar 791 inside the opening 790R. Further, as shown in FIG. 4, the housing 790 is inserted with the rod portion 71 a of the oil passage forming rod 71 inside. Further, the housing 790 is provided so as to be sandwiched between the step portion 71 b of the oil passage forming rod 71 and the valve unit 61. The housing 790 includes a guide portion 792 and an oil passage 793 communicating with the guide portion 792.

  The guide portion 792 is a substantially cylindrical hole that penetrates the other side of the housing 790 in the rod axis direction but does not penetrate one side. As shown in FIG. 5A, a plurality of guide portions 792 are formed at equal intervals in the circumferential direction of the housing 790. In the present embodiment, five are provided corresponding to the number of pressing members 78.

  In addition, since the guide portion 792 includes two or more holes, the guide portion 792 has the first damping valve 63 from the closed side of the first damping valve 63 compared to a continuous annular shape in plan view. The pressure receiving area to be pressed can be reduced. As a result, regardless of the size of the pressure receiving area on the valve opening side of the first damping valve 63, by changing the pressure receiving area on the valve closing side by increasing or decreasing the number of holes in the guide portion 792, The pressing force from the valve closing side can be adjusted in accordance with the size of the pressure receiving area on the valve opening side of the first damping valve 63.

  As shown in FIG. 5B, the guide portion 792 is provided in a direction substantially perpendicular to the surface formed by the first damping valve 63 when the valve is closed. Therefore, in this embodiment, the pressing member 78 guided by the guide portion 792 can be pressed in the substantially vertical direction against the first damping valve 63. In addition, since the guide portion 792 is provided in a substantially vertical direction with respect to the first damping valve 63, it is possible to facilitate processing when the guide portion 792 is formed.

  As shown in FIG. 5A, the oil passage 793 is a through hole formed in the radial direction from the inner periphery of the housing 790 toward the guide portion 792. The oil passage 793 is provided on the inner periphery of the housing 790 so as to face an oil passage 794 described later of the collar 791.

  The collar 791 includes an opening 791R. It is a member formed in a substantially disk shape. The collar 791 has an inner diameter substantially equal to the outer diameter of the oil passage forming rod 71. Further, the outer diameter of the collar 791 is formed substantially equal to the inner diameter of the housing 790. Further, the collar 791 includes an oil passage 794 extending radially from the inner periphery toward the outer periphery. The oil passage 794 communicates with the oil passage 712 (see FIG. 4) of the oil passage forming rod 71 on the inner periphery of the collar 791, and communicates with the oil passage 793 on the outer periphery of the collar 791.

  As shown in FIG. 4, the washer 761 holds the second damping valve 64 at the other end of the flow path forming member 62 on the other side of the valve unit 61. The nut 762 is fitted into a male screw (not shown) formed near the other end of the rod portion 71 a of the oil passage forming rod 71. The nut 762 is fixed so as to press the washer 761 toward one side. The nut 762 sandwiches the washer 761, the valve unit 61, and the valve pressing portion 79 between the step portions 71 b of the oil passage forming rod 71 and holds the oil passage forming rod 71.

  Here, in this embodiment, the pressing member 78 is formed in a substantially spherical shape. Therefore, the curvature part of the guide part 792 and the pressing member 78 contacts. In this state, the pressing member 78 contacts the guide portion 792 substantially perpendicular to the moving direction of the pressing member 78. And the guide part 792 hold | maintains the pressing member 78 so that a movement is possible.

  In the present embodiment, when there is a clearance between the pressing member 78 and the guide portion 792, the arc-shaped contact portion is in a state where the pressing member 78 is partially in contact with the guide portion 792. It is formed. Further, when there is no clearance between the pressing member 78 and the guide portion 792, contact portions for the entire circumference of the pressing member 78 with respect to the guide portion 792 are formed. In any case, the pressing member 78 is configured to contact the guide portion 792 substantially perpendicular to the moving direction of the pressing member 78.

<Operation of hydraulic shock absorber 1>

  FIG. 6A is a diagram showing the oil flow of the damping force adjusting mechanism 50 during the pressure stroke, and FIG. 6B is a diagram showing the oil flow of the damping force adjusting mechanism 50 during the extending stroke.

  First, the pressure stroke will be described. During the pressure stroke, as shown in FIG. 1, the piston 22 located at the end of the rod member 21 moves toward the vehicle body side of the inner cylinder 12. At this time, the oil in the piston-side oil chamber 12 </ b> A is compressed by the movement of the piston 22 and flows into the oil passage 111. Then, the oil flows from the piston side oil chamber 12A to the first oil chamber 50A through the oil passage 111 as shown in FIG.

  The oil that has flowed into the first oil chamber 50 </ b> A flows from the oil path 623 to the pressure side flow path 621 of the flow path forming member 62. Furthermore, the oil that has flowed into the pressure-side flow path 621 flows into the second oil chamber 50C while opening the second damping valve 64 by bending it to the other side. Since the second damping valve 64 covers the pressure side flow path 621, the oil flows from the pressure side flow path 621 to the second oil chamber 50C, but does not flow backward.

  The oil that has flowed into the second oil chamber 50C flows into the piston rod side oil chamber 12B through the oil passage 112 and the oil passage 12L (see FIG. 1).

  Note that the oil (indicated by a broken line in FIG. 6A) that flows into the oil passage 714 from the first oil chamber 50 </ b> A flows into the oil passage 735. Then, the oil that has flowed into the oil passage 735 flows into the oil passage 732. The oil that has flowed into the oil passage 732 flows into the oil passage 734. Further, the oil that has flowed through the oil passage 734 flows into the oil passage 733. Further, the oil that has flowed into the oil passage 733 flows into the oil passage 739. When the needle 736 is opened, the oil that has flowed to the oil passage 739 flows to the oil passage 731 through the restriction 736S. Further, the oil that has flowed to the oil passage 731 flows to the oil passage 711 of the oil passage forming rod 71. The oil that has flowed into the oil passage 711 flows toward the oil passage 712 and the second oil chamber 50C.

  Further, during the pressure stroke, as shown in FIG. 1, the piston 22 is inserted into the inner cylinder 12, whereby the volume of the piston side oil chamber 12A is reduced and the volume of the piston rod side oil chamber 12B is increased. Here, there is a difference in the volume of oil that can be accommodated between the piston rod side oil chamber 12B in which the rod member 21 exists in the inner cylinder 12 and the piston side oil chamber 12A in which the rod member 21 does not exist inside. That is, the amount of increase in the oil storage volume of the piston rod side oil chamber 12B is smaller than the amount of decrease in the oil storage volume of the piston side oil chamber 12A accompanying the movement of the piston 22. Therefore, surplus for the volume of entry of the rod member 21 occurs in the oil flowing from the piston side oil chamber 12A to the piston rod side oil chamber 12B. As shown in FIG. 6A, when the oil flows into the second oil chamber 50C from the first oil chamber 50A, the oil corresponding to the volume of entry of the rod member 21 is communicated 41L (see FIG. 3). To the sub tank oil chamber 41A.

  Next, the extension process will be described. During the extension stroke, as shown in FIG. 1, the piston 22 located at the end of the rod member 21 moves toward the axle side of the inner cylinder 12. At this time, the movement of the piston 22 compresses the volume of the oil in the piston rod side oil chamber 12B, and the volume of oil corresponding to the piston 22 and the rod member 21 flows into the oil passage 12L through the opening 12H. And the oil which flowed to the oil path 12L flows into the 2nd oil chamber 50C, as shown in FIG.6 (b).

  Then, the oil that has flowed into the second oil chamber 50 </ b> C flows from the oil path 624 to the extension-side flow path 622 of the flow path forming member 62. Furthermore, the oil that has flowed into the extension-side flow path 622 flows into the first oil chamber 50A while the first damping valve 63 is bent and opened to one side. A damping force is generated by the resistance that blocks the flow of oil by the first damping valve 63. Since the first damping valve 63 covers the expansion side flow path 622, the oil flows from the expansion side flow path 622 to the first oil chamber 50A, but does not flow backward.

  The oil that has flowed into the first oil chamber 50A flows from the oil passage 111 (see FIG. 1) to the piston-side oil chamber 12A.

  Further, during the extension stroke, as shown in FIG. 1, the piston 22 moves to the axle side of the inner cylinder 12, whereby the volume of the piston-side oil chamber 12 </ b> A is increased and the volume of the piston rod-side oil chamber 12 </ b> B is reduced. To do. At this time, due to the difference in the oil storage volume between the piston rod side oil chamber 12B in which the rod member 21 exists inside and the piston side oil chamber 12A in which the rod member 21 does not exist inside, the piston rod side oil chamber 12B changes to the piston side. When flowing into the oil chamber 12A, a shortage of oil occurs. As shown in FIG. 6 (b), this shortage of oil flows through the sub-tank oil chamber 41A through the communication passage 41L (see FIG. 3) when the oil flows from the second oil chamber 50C to the first oil chamber 50A. Supplied from

  Further, the oil that has flowed into the second oil chamber 50 </ b> C flows into the oil passage 711. The oil that has flowed into the oil passage 711 is divided into two oil passages 712 and an oil passage 731. The oil that has flowed into the oil passage 712 flows from the oil passage 712 to the oil passage 794. Further, the oil that has flowed to the oil passage 794 flows to the guide portion 792 through the oil passage 793. Thereby, the oil that has flowed to the guide portion 792 presses the pressing member 78 to the other side. That is, the oil that has flowed to the guide portion 792 urges a pressing force that presses the first damping valve 63 against the other side, which is the direction in which the extension-side flow path 622 of the flow path forming member 62 is closed.

  Here, the oil flowing through the oil passage 711 is increased in pressure by the throttle 736S, and the oil pressure in the oil passage 712 is also increased. Furthermore, the oil pressure in the oil passage 794, the oil passage 793, and the guide portion 792 communicating with the oil passage 712 increases. Then, as the oil pressure in the guide portion 792 increases, the pressing force that presses the pressing member 78 toward one side increases. The pressing force can be determined by the opening of the diaphragm 736S adjusted by the solenoid unit 75.

  On the other hand, the oil (indicated by a broken line in FIG. 6B) that has flowed through the oil passage 731 flows through the throttle 736S into the oil passage 739 when the needle 736 is opened. Further, the oil that has flowed to the oil passage 739 flows to the oil passage 733. Further, the oil that has flowed into the oil passage 733 flows into the oil passage 734. Then, the oil that has flowed into the oil passage 734 flows into the oil passage 732. The oil that has flowed into the oil passage 732 flows into the oil passage 735. Further, the oil that has flowed to the oil passage 735 flows to the oil passage 714 of the oil passage forming rod 71. Then, the oil that has flowed into the oil passage 714 flows into the first oil chamber 50A.

  As described above, in the hydraulic shock absorber 1 according to the present embodiment, the damping force adjusting mechanism 50 generates a damping force with the operation of the piston rod portion 20. Then, the amplitude operation of the suspension spring 31 is attenuated. In addition, the oil pressure in the guide portion 792 is increased by the oil flow through the oil passage 711 of the oil passage forming rod 71. Then, the pressing member 78 accommodated in the guide portion 792 presses the first damping valve 63 in a direction in which the first damping valve 63 closes the extension side flow path 622 of the flow path forming member 62. Thereby, the damping force in the hydraulic shock absorber 1 is controlled.

  Here, a clearance (gap) of several microns may occur between the pressing member 78 and the guide portion 792 due to manufacturing tolerances or the like. In this case, oil leaks through the clearance between the pressing member 78 and the guide portion 792. However, due to the clearance generated between the pressing member 78 and the guide portion 792, the damping at the time of a very low speed operation in which the piston rod portion 20 swings relatively slowly with respect to the cylinder portion 10 as shown in FIG. It is also possible to reduce the force.

  In other words, in the case of a very low speed operation in which the piston rod portion 20 swings relatively slowly with respect to the cylinder portion 10, it is possible to reduce the damping force and give priority to ride comfort. In such a case, it is necessary to form a low-speed flow path that allows oil flow at low speeds to suppress an increase in damping force. In the hydraulic shock absorber 1 of this embodiment, the clearance between the guide portion 792 and the pressing member 78 can also function as a low-speed flow path. By configuring in this way, both the reduction of the damping force when the moving speed of the piston rod portion 20 is very low and the improvement of the damping force when the moving speed of the piston rod portion 20 shifts to a high speed are achieved. It doesn't matter.

  Subsequently, the adjustment of the damping force in the hydraulic shock absorber 1 of the present embodiment will be described.

  In the hydraulic shock absorber 1 of the present embodiment, the damping force is adjusted by the back pressure adjusting unit 70 as shown in FIG. That is, by moving the needle 736 forward and backward with respect to the oil passage 731 of the needle receiving portion 737 by the coil 751, the opening of the throttle portion 736S is changed and the oil pressure of the guide portion 792 is changed through the oil pressure of the oil passage 711. The amount of bending of the first damping valve 63 described above is adjusted.

  For example, when the opening of the throttle portion 736S between the needle 736 and the oil passage 731 is reduced, the oil pressure in the oil passage 711 increases. As a result, the pressure of the guide portion 792 of the housing 790 communicating with the oil passage 711 is increased. And the pressing force which presses the other side which is the direction which closes the 1st damping valve 63 in which the oil pressure of the guide part 792 biases the pressing member 78 increases. And the damping force which generate | occur | produces in the damping force adjustment mechanism 50 becomes high.

  On the other hand, when the opening degree of the throttle portion 736S between the needle 736 and the oil passage 731 is increased, the first oil chamber 50A is passed from the oil passage 711 through the passage formed by the oil passage 731, the oil passage 732, and the oil passage 714. It becomes easy for oil to flow into the head (see FIG. 6A or FIG. 6B). Therefore, the pressure in the oil passage 711 is released to the first oil chamber 50A, and the pressure in the oil passage 711 decreases. As a result, the pressure of the guide portion 792 of the housing 790 communicating with the oil passage 711 is reduced. And the pressing force which presses the other side which is the direction which closes the 1st damping valve 63 which the oil pressure of the guide part 792 biases against the pressing member 78 falls. And the damping force which generate | occur | produces in the damping force adjustment mechanism 50 becomes low.

  5B, the contact portion T between the pressing member 78 and the guide portion 792 is formed in the circumferential direction of the pressing member 78. On the other hand, the moving direction D of the pressing member 78 is formed along the axial direction of the guide portion 792 in this embodiment. The contact portion T is formed substantially perpendicular to the moving direction D of the pressing member 78. The state in which the pressing member 78 is in contact with the guide portion 792 substantially perpendicular to the moving direction D of the pressing member 78 is maintained regardless of the inclination (rotation) state of the pressing member 78 in this embodiment. Therefore, in the present embodiment, the pressing member 78 is not easily caught on the guide portion 792, and so-called galling is unlikely to occur. Therefore, the hydraulic shock absorber 1 according to the present embodiment can realize highly reliable variable damping force.

  Moreover, the damping force in the hydraulic shock absorber 1 can be easily set by changing the number of the pressing members 78. That is, when it is desired to increase the damping force, the number of pressing members 78 is set to be increased. Conversely, when it is desired to further reduce the damping force, the number of pressing members 78 is decreased. As described above, in the hydraulic shock absorber 1 according to the present embodiment, the setting of the damping force can be easily changed only by performing the setting of changing the number of the pressing members 78.

  FIG. 7A is a diagram showing a case where the positions of the pressing member 78 and the extension side flow path 622 all overlap, and FIG. 7B is a partial view of the positions of the pressing member 78 and the extension side flow path 622. FIG. 7C is a diagram showing a case where the pressing member 78 and the extension-side flow path 622 are arranged on different circumferences at different distances from the center of the housing 790 in plan view. is there.

  In the present embodiment, six extending side flow paths 622 of the flow path forming member 62 that the first damping valve 63 opens and closes are formed. The pressing member 78 is configured to press the first damping valve 63. Here, consider a case where the number of pressing members 78 is set to six. In this case, when the flow path forming member 62 or the housing 790 is rotated around the oil path forming rod 71, the position of the pressing member 78 and the flow path forming member 62 depending on the rotational phase, as shown in FIG. There is a possibility that the position of the extension side flow path 622 overlaps. When the pressing member 78 overlaps all the extension side channels 622, all the extension side channels 622 that act to push the first damping valve 63 open are pressed down. Therefore, in this state, the damping force becomes extremely large as compared with a state in which only a part of the plurality of extension-side flow paths 622 overlap. Thus, in the case of a configuration in which a state in which the damping force becomes extremely large can be set, it is difficult to set the damping force.

  Therefore, in the present embodiment, the extension side channel 622 is formed at six locations and the five pressing members 78 are provided, and the number of the extension side channels 622 and the number of the pressing members 78 of the channel forming member 62 are determined. Are both indivisible numbers. The phases of the pressing members 78 and the flow path forming member 62 are shifted from each other. Therefore, as shown in FIG. 7B, any of the plurality of oil passages does not overlap with the pressing member 78 regardless of the rotational phases of the housing 790 and the flow passage forming member 62. In this way, it is desirable to prevent a situation where the damping force becomes extremely large.

  It should be noted that the number of pressing members 78 and the number of oil passages of the flow path forming member 62 are not limited to be in a divisible relationship. For example, by providing a rotation stopper or the like between the flow path forming member 62 and the housing 790, the positional relationship between the oil path of the flow path forming member 62 and the pressing member 78 is fixed so that the above-described influence due to the phase does not occur. May be.

  Furthermore, for example, when the shape of the extension-side flow path 622 provided in the flow path forming member 62 is formed in an annular shape, for example, a state where all do not overlap regardless of the position of the pressing member 78 is formed. Therefore, when the shape of the extension side flow path 622 is formed in an annular shape, for example, it is not necessary to limit the relationship between the number of the extension side flow paths 622 or the pressing members 78 or provide a rotation stopper.

  Further, as shown in FIG. 7C, for example, the outer circumference R1 and the inner circumference R2 are set by changing the distance from the center of the housing 790 in plan view. Among the pressing members 78, those arranged on the circumference R1 are referred to as pressing members 78a, and those arranged on the circumference R2 are referred to as pressing members 78b. In the example shown in FIG. 7C, the extension-side flow path 622 and the guide portion 792 are also arranged on the circumference R1 and the circumference R2, and the arrangement on the circumference R1 is replaced with the extension-side flow path 622a and the guide. The portion 792a, which is disposed on the circumference R2, serves as the extension-side flow path 622b and the guide portion 792b.

  Here, the radius r2 of the circumference R2 is smaller than the radius r1 of the circumference R1. For this reason, when the pressing member 78a is disposed on the circumference R1 having the large radius r1 during the extension stroke, the flow rate of the oil at which the first damping valve 63 starts to bend to one side is changed from the low speed range to the first damping valve 63. Press in the valve closing direction. Accordingly, it is possible to increase the resistance force that blocks the flow of oil from which the first damping valve 63 is opened from the low speed range.

  On the other hand, when the pressing member 78b is disposed on the circumference R2 having the small radius r2 during the extending stroke, the flow rate of the oil at which the first damping valve 63 starts to bend to one side is changed from the middle to high speed range to the first damping valve 63. Press in the valve closing direction. Thereby, it is possible to increase the resistance force that blocks the flow of oil from which the first damping valve 63 is opened from the middle to high speed range. Of course, only one of the pressing members 78a and 78b may be arranged with respect to the first damping valve 63, or both of them may be arranged as shown in FIG. 7C.

  Therefore, the point of action on the first damping valve 63 that the pressing member 78 presses the first damping valve 63 in the valve closing direction from the low speed range to the medium to high speed range can be widely changed. Therefore, a wide range of damping force can be set by disposing the pressing member 78 at a position having a different radius in the plan view shown in FIG.

  In addition, a spherical member such as a pressing member 78 may be a general-purpose product such as a bearing ball, which is relatively easily available. This makes it possible to keep manufacturing costs low. Further, the processing of the guide portion 792 in the housing 790 for holding the pressing member 78 can also be performed by a relatively simple process of forming a cylindrical opening. For this reason, manufacturing cost can be suppressed low.

  Moreover, you may comprise the pressing member 78 so that the surface of metal spheres may be covered with resin materials, such as urethane rubber, for example. The pressing member 78 may be a resin material formed into a spherical shape. Since at least the surface of the pressing member 78 is formed of resin in this way, when the first damping valve 63 is pressed by the hydraulic pressure in the valve closing direction, the surface of the pressing member 78 is roded by the first damping valve 63 and oil. By being sandwiched in the axial direction, the resin around the pressing member 78 is deformed so as to spread in the radial direction of the guide portion 792. As a result, the clearance (gap) between the guide portion 792 and the pressing member 78 is filled to improve the sealing performance, and the amount of oil leakage in the guide portion is suppressed. As a result, the pressure in the guide portion 792 is likely to increase, and for example, the valve closing pressure for the first damping valve 63 can be increased.

  FIGS. 8A to 8C are diagrams for explaining pressing members 177, 277, and 377 of other embodiments.

  For example, as shown in FIG. 8A, the pressing member 177 of the first other embodiment has an end 177a formed in a hemispherical shape and an end 177b formed in a rectangular shape. The pressing member 177 formed in this way may be accommodated in the guide portion 792 of the housing 790. Even in this case, the curved portions 177 c and 177 d of the hemispherical portion are in contact with the inner periphery of the guide portion 792. Therefore, the contact portion T in the pressing member 177 is formed substantially perpendicular to the moving direction D of the pressing member 177.

  Further, as shown in FIG. 8 (b), the pressing member 277 of the second other embodiment has end portions 277a and 277b each having a rectangular shape and has curved portions 277c and 277d. The pressing member 277 formed in this way may be accommodated in the guide portion 792. Even in this case, the curvature portions 277 c and 277 d are in contact with the inner periphery of the guide portion 792. Therefore, the contact portion T in the pressing member 277 is formed substantially perpendicular to the moving direction D of the pressing member 277.

  Further, as shown in FIG. 8C, the pressing member 377 of the third other embodiment is formed in a substantially elliptical shape in which the directions of the end portions 377a and 377b are long. The pressing member 377 formed in this way may be accommodated in the guide portion 792 so that the directions of the end portions 377a and 377b are along the axial direction of the guide portion 792. Also in this case, the elliptical curvature portions 377c and 377d are in contact with the inner periphery of the guide portion 792. Therefore, the contact portion T in the pressing member 377 is formed substantially perpendicular to the moving direction D of the pressing member 377.

  As described above, the pressing members 177, 277 and 377 of the other embodiments configured to have the curvature portion and come into contact with the guide portion 792 are accommodated in the guide portion 792, thereby pressing members 177 and 277. 377 can be in contact with the guide portion 792 substantially perpendicularly to the moving direction D. For example, even when the pressing members 177, 277, and 377 of the other embodiments are inclined, the pressing members 177, 277, and 377 of the other embodiments with respect to the guide portion 792 are not galled. Then, the occurrence of problems such as the damping force cannot be changed is prevented.

Second Embodiment

  FIG. 9A is a plan view of the valve pressing portion 81 in the hydraulic shock absorber 1 of the second embodiment, and FIG. 9B is a cross-sectional view taken along the line IXb-IXb shown in FIG. FIG. 9C is a view for explaining the action of force in the pressing member 78 and the guide portion 812 shown in FIG.

  The valve pressing portion 81 is different from the valve pressing portion 79 of the first embodiment described above. In the description of the second embodiment, the same members in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 9A and 9B, the valve pressing portion 81 includes a pressing member 78 disposed on one side of the valve unit 61 (see FIG. 4), and a housing 810 that holds the pressing member 78. And a collar 791 disposed between the housing 810 and the oil passage forming rod 71 (see FIG. 4).

  As shown in FIG. 9A, the housing 810 includes an opening 810R. It is formed in a substantially disc shape. The housing 810 holds the collar 791 inside the opening 810R. In addition, the housing 810 includes a guide portion 812 and an oil passage 813 communicating with the guide portion 812.

  The guide part 812 is a hole formed in a substantially cylindrical shape. And as shown to Fig.9 (a), the guide part 812 is formed with two or more (in this embodiment) at equal intervals in the circumferential direction. In the present embodiment, one pressing member 78 is accommodated in one guide portion 812. The guide portion 812 is in contact with the pressing member 78 substantially perpendicular to the moving direction of the pressing member 78. And the guide part 812 hold | maintains the pressing member 78 so that a movement is possible.

  In addition, the guide portion 812 is provided so as to be inclined so as to form an angle θ with respect to the main surface 63a of the first damping valve 63 that is not deformed. Note that the guide portion 812 is not limited to be formed to extend obliquely in the circumferential direction, and may be provided to be inclined with respect to the first damping valve 63. In this embodiment, the pressing member 78 can press the first damping valve 63 in an oblique direction.

  The oil passage 813 is a through-hole formed in the radial direction from the guide portion 812 toward the inner periphery of the housing 810. The oil passage 813 is provided so as to communicate with the oil passage 794 of the collar 791 on the inner periphery of the housing 810.

  In the housing 810 configured as described above, the oil passage 794 communicates with the oil passage 712 (see FIG. 4) of the oil passage forming rod 71 on the inner peripheral side of the collar 791. Further, the oil passage 813 communicates with the oil passage 794 on the inner peripheral side of the housing 810. Accordingly, the oil passage 712 (see FIG. 4), the oil passage 794, the oil passage 813, and the guide portion 812 of the oil passage forming rod 71 communicate with each other.

Next, the action of force in the valve pressing portion 81 will be described with reference to FIG. Here, the pressing member 78 and the first damping valve 63 are used as a specific example. Here, the force pressing member 78 is pushed by the pressure of the oil in the guide portion 812 and f _1. Also, the force pressing member 78 receives from the inner surface of the guide portion 812 and _{f 2.} Further, F is a force that the first damping valve 63 receives from the pressing member 78. The relational expression of force is as follows.

f ₁ · cos θ = f ₂ · sin θ [Formula 1]

F = f ₁ · sin θ + f ₂ · cos θ [Formula 2]

Substituting [Equation 1] into [Equation 2] gives F = f ₁ · sin θ + (cos θ / sin θ) · f ₁ · cos θ [Equation 3].

Then, rearranging [Expression 3], F = (sin ² θ + cos ² θ) / sin θ · f ₁ [Expression 4] is obtained.

Further, rearranging [Expression 4], F = (1 / sin θ) · f ₁ [Expression 5] is obtained.

Here, for example, when the angle θ is set to 90 °, as described with reference to FIGS. 5A and 5B, the guide portion 792 is set to be perpendicular to the first damping valve 63. It corresponds to the case. In this case, based on [Equation 5], the relationship is F = f ₁ . Therefore, the force F received by the first damping valve 63 from the pressing member 78 is a force f _{1 at} which the pressing member 78 is pressed by the oil pressure of the guide portion 792.

In the relationship represented by [Formula 5], when the pressure applied to the guide portion 812 is constant, the oil pressure of the guide portion 812 is greater than or equal to the force pressing the pressing member 78 by adjusting the angle θ. The first damping valve 63 can be pushed with force. For example, when the angle θ is set to 60 °, F = (2 / √3) f ₁ = about 1.2f ₁ . Further, when the angle θ is set to 45 °, F = (√2) f ₁ = about 1.4f ₁ . Further, when setting the angle θ to 30 ° becomes F = 2f _1.

  As described above, the guide member 812 is inclined with respect to the first damping valve 63, so that the pressing member 78 is compared with the case where the guide portion 812 is formed substantially perpendicular to the first damping valve 63 as in the guide portion 792. The force that pushes the valve can be increased. Therefore, the damping force per one pressing member 78 can be increased.

  9B, in the valve pressing portion 81, the contact portion T between the pressing member 78 and the guide portion 812 is formed in the circumferential direction of the pressing member 78. The moving direction D of the pressing member 78 is formed along the axial direction of the guide part 812 in this embodiment. The contact portion T is formed substantially perpendicular to the moving direction D of the pressing member 78. The state in which the pressing member 78 is in contact with the guide portion 792 substantially perpendicular to the moving direction D of the pressing member 78 is maintained regardless of the inclination (rotation) state of the pressing member 78 in this embodiment. Therefore, in this embodiment, the pressing member 78 is not easily caught by the guide portion 812, and so-called galling is difficult to occur.

  FIGS. 10A and 10B are views for explaining the clearance between the guide portion 812 and the pressing member 78. FIG.

For example, the pressing member 78 as shown in FIG. 10 (a) when not in contact with the inner wall of the guide portion 812, an annular gap S ₁ is formed between the pressing member 78 and the guide portion 812. As shown in FIG. 10B, when the pressing member 78 contacts the inner wall of the guide portion 812, a C-shaped gap S ₂ is formed between the pressing member 78 and the guide portion 812.

According to Hagen-Poiseuille's law, which generally represents the flow characteristics of viscous fluids such as oil, the flow velocity of viscous fluid flowing through a cylindrical tube with a constant tube diameter is relative to the center side of the cylindrical tube when viewed in cross section. The inner wall side of the cylindrical tube becomes faster and slower. Therefore, if the flow annular gap S ₁ and C-shaped, respectively oil and interstices S ₂ of FIG. 10, as difference in the flow of oil, the amount of leakage each oil in the gap S _1, S ₂ Is different.

Here, in the first embodiment shown in FIG. 5B, since the guide portion 792 is substantially perpendicular to the first damping valve 63, the pressing member 78 moves freely within the guide portion 792, so that the pressing member 78. the gap between the guide portion 792 and is caused randomly in accordance with the annular gap S ₁ and C-shaped gap S ₂ shown in FIG. 10 situation. For this reason, when the guide part 792 of 1st Embodiment is substantially perpendicular | vertical to the 1st damping valve 63, variation arises in the amount of oil leaks.

On the other hand, in the second embodiment, since the guide portion 812 is inclined with respect to the first damping valve 63, the pressing member 78 has the oil of the guide portion 812 as shown in FIG. A resultant force G of the force f ₁ pushed by the pressure and the force F received by the pressing member 78 from the first damping valve 63 acts. By this force G acts on the pressing member 78, the pressing member 78 is always in contact with the inner wall of the guide portion 812, the size of the C-shaped clearance S ₂ shown in Fig. 10 (b) is maintained stably. For this reason, the amount of oil leakage in the gap between the guide portion 792 and the pressing member 78 is stabilized, so that the damping force is stabilized and the setting for adjusting the damping force is facilitated.

  As described above, a plurality of types of housings having different angles θ with respect to the first damping valve 63 of the guide portion 812 are prepared, and when adjusting the damping force, a desired housing is attached to the hydraulic shock absorber 1 as necessary. The damping force in the hydraulic shock absorber 1 may be configured to be variable.

  Further, for example, a cylindrical member that forms the guide portion 812 is provided, and the angle θ of the cylindrical member is configured to be variable so that the angle θ of the guide portion 812 with respect to the first damping valve 63 can be changed. . Accordingly, the damping force can be varied by changing the pressing force of the first damping valve 63 by changing the angle θ of the cylindrical member.

<Third Embodiment>

  FIG. 11 is a diagram for explaining the pressing member 78 and the guide portion 1792 in the hydraulic shock absorber 1 of the third embodiment.

  As shown in FIG. 11, a guide portion 1792 formed in a curved path shape may be used as a path for guiding the pressing member 78 to be movable. Similarly, the guide portion 1792 hardly causes galling with the pressing member 78. That is, the contact portion T is formed substantially perpendicular to the moving direction D of the pressing member 78. In this embodiment, the state in which the pressing member 78 is in contact with the guide portion 1792 substantially perpendicular to the moving direction D of the pressing member 78 is maintained regardless of the inclination (rotation) state of the pressing member 78. Therefore, in this embodiment, the pressing member 78 is not easily caught by the guide portion 1792, and so-called galling is difficult to occur.

<Fourth embodiment>

  FIG. 12 is a view for explaining the pressing member 278 and the guide portion 2792 in the hydraulic shock absorber 1 of the fourth embodiment.

  As shown in FIG. 12, the pressing member 278 is formed in a substantially cylindrical shape. Further, the guide portion 2792 has a curvature that is convex toward the center of the cylinder. Even in this case, the contact portion T of the pressing member 278 is formed substantially perpendicular to the moving direction D of the pressing member 278. Therefore, galling is less likely to occur between the pressing member 278 and the guide portion 2792.

<Fifth Embodiment>

  FIG. 13 is a view for explaining the valve pressing portion 281 in the hydraulic shock absorber 1 of the fifth embodiment.

  The valve pressing unit 281 is a first pressing unit disposed opposite to the other side of the first valve 163 that opens and closes the first channel 2621 according to the flow of oil toward the other side of the first channel 2621. The second valve 263 is disposed opposite to the member 378 and the first pressing member 378 and opens and closes the second flow path 2622 according to the flow of oil toward one side of the second flow path 2622. A second pressing member 478 disposed on one side, a housing 2810 for holding movement of the first pressing member 378 and the second pressing member 478, a housing 2810 and an oil passage forming rod 71 (see FIG. 4); And a collar 791 (not shown) disposed between the two.

The housing 2810 has a guide portion 3792 in which the first pressing member 378 and the second pressing member 478 are accommodated. In the guide portion 3792, the first pressing member 378 and the second pressing member 478 are arranged in series. The guide portion 3792 is a hole penetrating the housing 2810 and substantially perpendicular to the first valve 163 and the second valve 263. Therefore, the moving direction D ₁ in which the first pressing member 378 moves becomes substantially perpendicular to the first valve 163, the moving direction D ₂ of the second pressing member 478 is moved from the second valve 263 substantially It becomes vertical. Therefore, the contact between the guide portion 3792 and the first pressing member 378 and _{T 1,} the points of contact with the guide portion 3792 and the second pressing member 478 and _{T 2,} the contact portion _{T 1} and the moving direction _{D 1} is substantially becomes vertical, likewise the contact portion T ₂ and the moving direction D ₂ also substantially vertical.

  Further, the guide portion 3792 has a pressing force against the first valve 163 on the first pressing member 378 and a second pressing member 478 on the second pressing member 478 by hydraulic pressure caused by oil flowing in from a flow path (not shown). The pressing force to the two valves 263 can be collectively urged. For this reason, the hydraulic shock absorber 1 in which the first pressing member 378 and the second pressing member 478 are arranged in series on the guide portion 3792 shown in FIG. 13 has a damping force according to the flow of fluid on one side and the other side. The mechanism for changing can be simplified.

  In each of the present embodiments shown in the first to fifth embodiments, the pressing member 78 is formed by pressurizing the oil in the guide portion 792 of the housing 790 using the oil passage forming rod 71, the solenoid portion 75, and the like. The structure which urges | biases toward the 1st damping valve 63 side is employ | adopted. For this reason, in each embodiment, the damping force characteristic can be continuously varied by adjusting the oil pressure. However, the present invention is not limited to this. It is only necessary to be able to vary the pressing force that presses the pressing member 78 against the valve side. For example, a spring mechanism that changes the elastic force may be used. In addition, pressing with an elastic member such as a spring may be combined with pressurization with oil in each embodiment.

  In each of the embodiments, the example in which the damping force adjusting mechanism 50 is provided outside the outer cylinder 11 has been described. However, the present invention is not limited to this. For example, a configuration may be adopted in which a valve is provided in a piston that is provided in the outer cylinder 11 (or the inner cylinder 12) and moves in the axial direction, and a damping force is generated according to the pressure stroke and the extension stroke.

  Furthermore, although each embodiment demonstrated using the example which applies the damping-force adjustment mechanism 50 to the hydraulic shock absorber 1 provided between the rear-wheels and vehicle body in a two-wheeled vehicle etc. as mentioned above, it is limited to this. is not. For example, the damping force adjusting mechanism 50 of each embodiment can be applied to various pressure buffering devices, such as installing the damping force adjusting mechanism 50 on a front fork provided between a front wheel of a motorcycle or the like and a vehicle body.

DESCRIPTION OF SYMBOLS 1 ... Hydraulic shock absorber, 10 ... Cylinder part, 20 ... Piston rod part, 30 ... Spring part, 40 ... Sub tank, 50 ... Damping force adjustment mechanism, 50A ... 1st oil chamber, 50C ... 2nd oil chamber, 50H ... Space Forming member, 62 ... flow path forming member, 63 ... first damping valve, 64 ... second damping valve, 70 ... back pressure adjusting part, 71 ... oil passage forming rod, 75 ... solenoid part, 78 ... pressing member, 621 ... Pressure side flow path, 622 ... Extension side flow path, 790 ... Housing, 792 ... Guide part

Claims (7)

A pressure buffering device that generates a damping force by controlling the flow of fluid,
A flow path through which fluid flows;
A valve for opening and closing the flow path according to the flow of the fluid;
A pressing member provided to be capable of pressing the valve in a direction in which the valve is closed;
A guide unit for guiding the pressing member to be movable;
Urging means for urging the pressing force to press the pressing member in a direction to close the valve in a variable manner;
The pressure buffering device, wherein the pressing member is in contact with the guide portion substantially perpendicular to a moving direction of the pressing member. The pressure buffering device according to claim 1, wherein the guide portion includes two or more holes. The pressure buffering device according to claim 1, wherein the urging unit is a pressure of a fluid in the guide portion. The pressure buffering device according to any one of claims 1 to 3, wherein the guide portion is provided in a direction substantially perpendicular to the valve. The pressure buffer device according to any one of claims 1 to 3, wherein the guide portion is provided to be inclined with respect to the valve. The pressure buffering device according to any one of claims 1 to 5, wherein at least a surface of the pressing member is formed of a resin. The pressure buffering device according to any one of claims 1 to 6, wherein the pressing member is formed in a substantially spherical shape.

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