JP2013133896A - Damping force adjustment type shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten an axial length of a damping force adjusting valve and suppress occurrence of an abnormal noise or the like.SOLUTION: A damping force adjusting valve 22 includes a guide member 10, shutter member 23, and pin member 24. A mount end 24A of the pin member 24 axially extends into a shutter member 23 so as to radially face first and second shutter ports 23D and 23E of the shutter member 23. The shutter member 23 includes a cylindrical section 23A rotatably engaged with the inside of a shutter insertion hole 10B of the guide member 10, a lid section 23B closing the axial end of the cylindrical section 23A, and a cylindrical mount section 23C that extends axially from the lid section 23B into the cylindrical section 23A and to which a mount end 24A of the pin member 24 is engaged and mounted from the lid section 23B side.

Description

  The present invention relates to a damping force adjusting type shock absorber that is suitably used for buffering vibrations of, for example, an automobile.

  A vehicle such as a four-wheeled vehicle is provided with a damping force adjusting type shock absorber between the wheel side and the vehicle body side, and is configured to buffer upward and downward vibrations and the like generated during traveling. This damping force adjustment type shock absorber has a main passage formed on the piston side and a bypass passage provided on the piston rod side so as to bypass the main passage, and a damping force adjusting valve is used to The damping force generated in the cylinder is variably adjusted by changing the passage area (see, for example, Patent Document 1).

JP 2009-257456 A

  By the way, in the damping force adjusting type shock absorber according to the above-described prior art, a damping force adjusting valve is formed by a cylindrical shutter member, and a shutter port through which a working fluid flows is formed at a position facing the shutter member in the radial direction. Thus, the axial length of the damping force adjusting valve can be shortened. However, the working fluids flowing from the respective shutter ports into the shutter member may collide with each other in the radial direction as the flow rate increases, causing unexpected vortices and aeration. There is a problem that it also causes abnormal noise.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to reduce the axial length of the damping force adjustment valve and to suppress the occurrence of abnormal noise and the like. An object of the present invention is to provide a damping force adjusting shock absorber.

  In order to solve the above-described problems, the present invention includes a cylinder in which a working fluid is sealed, and a piston that is movably fitted in the cylinder and defines the chamber in two chambers, a rod side chamber and a bottom side chamber. A piston rod having one end fixed to the piston and the other end protruding to the outside of the cylinder, a main passage formed in the piston for communicating the rod side chamber and the bottom side chamber, and located in the rod side chamber. A sub-piston provided on the piston rod and arranged in a non-sliding state in the cylinder, and formed between the sub-piston and the piston rod, bypassing the main passage and communicating between the rod side chamber and the bottom side chamber A damping force adjusting shock absorber comprising: a bypass passage to be adjusted; and a damping force adjusting valve that variably adjusts a damping force by changing a passage area of the bypass passage. The damping force adjusting valve is a cylindrical guide member formed of a cylindrical body forming a part of the piston rod, and having a plurality of radial guide ports forming a part of the bypass passage on a peripheral wall; A shutter member that is rotatably provided in the guide member and has a plurality of shutter ports that are communicated with and cut off from the guide port, and is inserted into the piston rod to rotate the shutter member. Each guide port and each shutter port are provided at positions facing each other at 180 degrees in the circumferential direction, and the pin member is fixed to the shutter member. The mounting end side to be mounted is arranged at a position facing the shutter port in the radial direction.

  With the above configuration, since the working fluid flowing into the shutter member from each shutter port flows along the periphery of the mounting end side of the pin member, the working fluid does not directly collide with each other, and generation of abnormal noise or the like is suppressed. And the axial length of the damping force adjusting valve can be shortened.

1 is a longitudinal sectional view showing a damping force adjustment type hydraulic shock absorber according to an embodiment of the present invention. It is a longitudinal cross-sectional view which expands and shows the piston, subpiston, damping force adjustment valve, etc. in FIG. It is the cross-sectional view which expanded the damping force adjustment valve from the arrow III-III direction in FIG.

  Hereinafter, a case where the damping force adjusting shock absorber according to the embodiment of the present invention is applied to a damping force adjusting hydraulic shock absorber for a vehicle will be described as an example and described in detail with reference to the accompanying drawings.

  Here, FIG. 1 to FIG. 3 show an embodiment of the present invention. In FIG. 1, a cylindrical cylinder 1 forms an outer shell of a single cylinder type damping force adjusting hydraulic shock absorber, and a lower end portion of the cylinder 1 is closed by a bottom cap 2. A rod guide 3 for guiding a piston rod 7 described later is provided on the upper end side of the cylinder 1, and an upper cap 4 and a spring receiver 5 are attached so as to cover the rod guide 3. The spring receiver 5 supports a suspension spring (not shown) of the vehicle from below.

  A piston 6 is movably fitted in the cylinder 1, and the piston 6 defines the cylinder 1 in two chambers, a rod-side oil chamber A and a bottom-side oil chamber B. The piston 6 is formed with a plurality of oil passages 6A, 6B that can communicate with the rod-side oil chamber A and the bottom-side oil chamber B, respectively, spaced apart in the circumferential direction. The oil passages 6A, 6B It is comprised by the oil hole inclined diagonally with respect to 6 axis lines. The oil passages 6 </ b> A and 6 </ b> B constitute a main passage through which the oil liquid as the working fluid sealed in the cylinder 1 flows between the rod side oil chamber A and the bottom side oil chamber B.

  On the upper end face of the piston 6, there is an annular recess 6C formed so as to surround the upper opening of the oil passage 6A, and a compression side damping valve 13 (disc valve), which will be described later, located radially outside the annular recess 6C. An annular valve seat 6 </ b> D for separating and seating is provided. An annular recess 6E formed so as to surround the lower opening of the oil passage 6B is formed on the lower end surface of the piston 6, and an expansion-side damping valve 14 (disc valve), which will be described later, is located radially outside the annular recess 6E. Is provided with an annular valve seat 6F.

  7 is a piston rod extending in the axial direction in the cylinder 1. The piston rod 7 includes a cylindrical rod member 8 having a lower end as one end side inserted into the cylinder 1, and one side of the rod member 8 ( And a stepped cylindrical guide member 10 connected to the lower end side via a cylindrical joint member 9. The joint member 9 constitutes a part of the piston rod 7 and also serves as a spring receiver for a spring 29 described later.

  The piston 6 is attached to one end side of the piston rod 7 (that is, the lower end side of the guide member 10) in a state of being fastened by a nut 11 or the like. The nut 11 fixes the piston 6 to the guide member 10 and detachably fastens a contraction side and expansion side damping valves 13 and 14 described later on the upper and lower surfaces of the piston 6 in a detachable manner. Further, the other end side of the piston rod 7 (that is, the upper end side of the rod member 8) protrudes outside the cylinder 1 through the rod guide 3, the upper cap 4, and the like.

  As shown in FIG. 2, a pin insertion hole 10A into which a pin member 24 described later is inserted with a gap and a lower side of the pin insertion hole 10A are located on the inner peripheral side of the guide member 10 formed of a cylindrical body. A shutter insertion hole 10B extending in the axial direction and having a larger diameter than the pin insertion hole 10A is provided. In addition, a pin insertion hole (not shown) is also provided on the inner peripheral side of the rod member 8 so as to communicate with the pin insertion hole 10A of the guide member 10 in the axial direction. Also, a pin member 24 described later is inserted with a gap.

  The shutter insertion hole 10 </ b> B of the guide member 10 has an open end 10 </ b> C whose lower end side always communicates with the bottom side oil chamber B. A shutter member 23, which will be described later, is rotatably fitted in the shutter insertion hole 10B. The upper end side of the shutter insertion hole 10B communicates with the pin insertion hole on the rod member 8 side via the pin insertion hole 10A in the upward and downward directions, and the pin insertion hole 10A and the shutter insertion hole 10B are axially connected to each other. Are arranged at substantially the same position.

  The guide member 10 of the piston rod 7 constitutes a part of a damping force adjusting valve 22 described later. As shown in FIG. 2, a plurality of guide ports 10D, 10E, etc. extending radially outward from the shutter insertion hole 10B are provided on the peripheral wall side of the shutter insertion hole 10B of the cylindrical guide member 10, respectively. They are spaced apart in the axial direction and the circumferential direction.

  Of these guide ports 10D, 10E, etc., each guide port 10D is arranged at a position communicating in the radial direction with a recess 15G of a sub-piston 15 described later, as shown in FIG. That is, each guide port 10D is configured by a total of two radial holes formed at positions facing each other in the radial direction at intervals of 180 degrees in the circumferential direction of the guide member 10.

  Further, each of the other guide ports 10E is disposed at a position communicating with the inside of an intermediate chamber D (described later) via a cylindrical spacer 19 in the radial direction as shown in FIG. That is, the guide port 10E is also constituted by a total of two radial holes formed at positions opposed to each other in the radial direction at intervals of 180 degrees in the circumferential direction of the guide member 10 similarly to the guide port 10D described above. Has been. Furthermore, an annular step portion 10 </ b> F in which a spacer 18 described later is positioned in the axial direction is formed on the outer peripheral side of the guide member 10.

  On the other hand, as shown in FIG. 1, a free piston 12 is slidably inserted into the cylinder 1 between the piston 6 and the bottom cap 2. The free piston 12 defines a gas chamber C in which pressurized gas is sealed on the bottom side of the cylinder 1. Here, the free piston 12 is pivoted in the cylinder 1 so that the gas chamber C is contracted and expanded in response to the piston rod 7 entering or leaving the cylinder 1. Sliding displacement in the direction. That is, the free piston 12 expands and contracts the gas chamber C so as to compensate for the entry volume of the piston rod 7.

  Reference numeral 13 denotes a reduction side damping force generation mechanism (hereinafter referred to as a compression side damping valve 13) provided on the upper surface side of the piston 6. The compression side damping valve 13 is a rod side oil chamber of the cylinder 1 as shown in FIG. It is constituted by a plurality of disc valves and the like that are located in A and are fixedly attached to the upper surface side of the piston 6. The compression-side damping valve 13 (disc valve) is formed with a small notch 13A that forms a fixed orifice with the annular valve seat 6D. The notch 13A is configured so that the oil fluid on the oil passage 6A side is the rod-side oil. It is allowed to flow toward the chamber A even when the compression side damping valve 13 is closed. Instead of the notch 13A, a fixed orifice made of a notch or the like may be provided on the annular valve seat 6D side.

  When the piston 6 is slid downward in the cylinder 1 during the reduction stroke of the piston rod 7, the compression side damping valve 13 is provided with the oil passages 6A, the annular recess 6C and the annular valve from the bottom side oil chamber B to the piston 6. A resistance force is applied to the oil fluid flowing toward the rod-side oil chamber A through the seat 6D side to generate a predetermined contraction-side damping force.

  Reference numeral 14 denotes an extension side damping force generation mechanism (hereinafter referred to as an extension side damping valve 14) provided on the lower surface side of the piston 6. The extension side damping valve 14 is a bottom side oil chamber of the cylinder 1 as shown in FIG. It is composed of a plurality of disc valves and the like that are located in B and are fixedly attached to the lower surface side of the piston 6. The expansion side damping valve 14 (disc valve) is formed with a small notch 14A that forms a fixed orifice with the annular valve seat 6F. The notch 14A is configured such that the oil on the oil passage 6B side is bottom oil. The flow toward the chamber B is allowed even when the expansion side damping valve 14 is closed. In place of the notch 14A, a fixed orifice made of a notch or the like may be provided on the annular valve seat 6F side.

  When the piston 6 slides upward in the cylinder 1 during the extension stroke of the piston rod 7, the extension-side damping valve 14 moves from the rod-side oil chamber A to the oil passages 6B of the piston 6, the annular recess 6E, and the annular valve. A resistance force is given to the oil liquid flowing toward the bottom side oil chamber B through the seat 6F side, and a predetermined extension side damping force is generated.

  A sub-piston 15 is provided in the guide member 10 of the piston rod 7 and is located in the rod-side oil chamber A. The sub-piston 15 contracts the piston 6 via a cap member 20 and a cylindrical spacer 19 which will be described later. It is disposed on the side damping valve 13. The sub-piston 15 has an outer diameter dimension smaller than the inner diameter of the cylinder 1 and is disposed in the cylinder 1 in a non-sliding state (that is, a state having a gap in the radial direction).

  The sub-piston 15 defines an intermediate chamber D between the cap member 20 described later, and this intermediate chamber D constitutes a part of a bypass passage 21 described later. The sub-piston 15 is formed with a plurality of oil passages 15A and 15B that can communicate with the rod-side oil chamber A and the intermediate chamber D, respectively, spaced apart in the circumferential direction. It is constituted by an oil hole inclined obliquely with respect to 15 axes. The oil passages 15 </ b> A and 15 </ b> B constitute a passage (a part of a bypass passage 21 to be described later) through which an oil liquid is circulated between the rod-side oil chamber A and the intermediate chamber D.

  An annular recess 15C formed so as to surround the upper opening of the oil passage 15A and an annular valve located on the radially outer side of the annular recess 15C and seated on the reduction side disk valve 16 are attached to the upper end surface of the sub-piston 15. A seat 15D is provided. An annular recess 15E formed so as to surround the lower opening of the oil passage 15B and an extension-side disk valve 17 positioned on the radially outer side of the annular recess 15E are seated on the lower end surface of the sub-piston 15. An annular valve seat 15F is provided.

  A notch (not shown) is provided between the reduction-side disc valve 16 and the annular valve seat 15D as a fixed orifice that allows oil to flow even when the reduction-side disc valve 16 is closed. Similarly, a notch (not shown) as a fixed orifice is provided between the extension-side disc valve 17 and the annular valve seat 15F.

  Further, on the inner peripheral side of the sub-piston 15, an annular recess having a lower surface side (one side in the axial direction) opened to communicate with the annular recess 15E and an upper surface side (the other side in the axial direction) is a closed end. A portion 15G is provided. The recessed portion 15G is formed so as to surround the guide port 10D of the guide member 10 from the outside in the radial direction, and always communicates the guide port 10D with the annular recess 15E of the sub piston 15 and the oil passage 15B.

  Reference numeral 18 denotes a spacer provided between the step portion 10F of the guide member 10 and the reduction-side disk valve 16, and the spacer 18 is constituted by an annular ring or the like provided by being fitted to the outer peripheral side of the guide member 10. Has been. The spacer 18 sandwiches the reduction-side disc valve 16 with the step portion 10F, and stabilizes the opening and closing operations of the reduction-side disc valve 16.

  Reference numeral 19 denotes a cylindrical spacer for positioning the extension-side disk valve 17 on the lower surface side of the sub-piston 15, and the cylindrical spacer 19 is configured by a covered cylindrical body that is provided so as to pass through the outer peripheral side of the guide member 10. Yes. The cylindrical spacer 19 sandwiches the extension-side disc valve 17 from the lower side with the annular valve seat 15F of the sub-piston 15, and stabilizes the opening and closing operations of the extension-side disc valve 17. The cylindrical spacer 19 is formed with a plurality of notches 19A as communication holes at intervals in the circumferential direction, and the notches 19A always communicate the intermediate chamber D with the guide ports 10E of the guide member 10. Is.

  Reference numeral 20 denotes a cap member that defines an intermediate chamber D with respect to the sub-piston 15. The cap member 20 is positioned on one side (lower surface side) in the axial direction and is inserted into the outer peripheral side of the guide member 10 so as to be compressed on the contraction side. An annular bottom portion 20A sandwiched between the valve 13 and the cylindrical spacer 19, an inclined cylinder portion 20B extending obliquely upward from the outer peripheral side of the bottom portion 20A, and an axial direction from the outer peripheral side of the inclined cylindrical portion 20B. It is comprised by the cylindrical cylindrical part 20C extended toward the side (upper side). The cap member 20 is fitted in a liquid-tight state at the upper end side of the cylindrical portion 20 </ b> C to the outer peripheral side of the sub-piston 15, whereby an intermediate chamber D is defined between the cap member 20 and the sub-piston 15.

  The cap member 20 has an outer diameter dimension smaller than the inner diameter of the cylinder 1 and is disposed in the cylinder 1 in a non-sliding state (that is, a state having a gap in the radial direction). The cap member 20 is fixed to the guide member 10 of the piston rod 7 via the sub-piston 15 and the cylindrical spacer 19. The cap member 20 moves up the cylinder 1 together with the sub-piston 15 and the cylindrical spacer 19. It moves downward.

  21 is a bypass passage formed between the guide member 10 of the piston rod 7 and the sub piston 15, and the bypass passage 21 includes oil passages 15A, 15B, annular recesses 15C, 15E and recesses 15G of the sub piston 15, and a guide member. 10 shutter insertion holes 10B, guide ports 10D, 10E, and the like. As a result, the bypass passage 21 bypasses the main passage (that is, the oil passages 6A and 6B) formed in the piston 6, and between the rod-side oil chamber A and the bottom-side oil chamber B, a shutter port 23D to be described later. It communicates via 23F etc.

  A damping force adjusting valve 22 variably adjusts the damping force by changing the passage area of the bypass passage 21. The damping force adjusting valve 22 rotates the guide member 10 that forms part of the piston rod 7, a shutter member 23 that is rotatably provided in the shutter insertion hole 10 </ b> B of the guide member 10, and the shutter member 23. In order to operate, it comprises the pin insertion hole of the rod member 8 and the pin member 24 as a rotation operation shaft provided by being inserted into the pin insertion hole 10A of the guide member 10.

  The pin member 24 has an end portion on one side in the axial direction that is fixedly attached to the shutter member 23 in a non-rotating state, and this attachment end portion 24A has a cross section D as shown in FIG. It is formed in a letter shape. The mounting end 24A of the pin member 24 is disposed so as to extend in the axial direction into the shutter member 23 so as to face the shutter ports 23D and 23E described later in the radial direction.

  The shutter member 23 of the damping force adjusting valve 22 includes a cylindrical portion 23A that is rotatably inserted into the shutter insertion hole 10B of the guide member 10, and an axial end portion (the upper end side in FIG. 2) of the cylindrical portion 23A. A lid portion 23B having a closed end), and a cylindrical attachment that extends in the axial direction from the lid portion 23B into the cylinder portion 23A and is fitted and attached from the lid portion 23B side to the attachment end portion 24A of the pin member 24 Part 23C.

  As shown in FIG. 3, the cylindrical mounting portion 23 </ b> C is formed as a fitting hole having a D-shaped cross section on the inner peripheral side, and the mounting end portion 24 </ b> A of the pin member 24 is fitted and attached in a non-rotating state. ing. The outer peripheral surface of the cylindrical mounting portion 23C has a circular shape in cross section, and an annular ring that forms a part of the bypass passage 21 communicates with shutter ports 23D and 23E described later between the cylindrical portion 23A and the cylindrical mounting portion 23C. A passage portion 25 (see FIG. 3) is provided. That is, the cylindrical mounting portion 23C extends from the outer side of the mounting end portion 24A of the pin member 24 in the axial direction, and is disposed at a position facing the shutter ports 23D and 23E in the radial direction.

  Here, the cylindrical portion 23A of the shutter member 23 communicates with and blocks the guide ports 10D of the guide member 10 from the first shutter port 23D and the second shutter port 23E, and the shutter ports 23D and 23E. A third shutter port 23 </ b> F and a fourth shutter port (not shown) are provided that are spaced apart from each other in the axial direction and communicate with and cut off from each guide port 10 </ b> E of the guide member 10.

  As shown in FIG. 3, the first shutter port 23D has a total of two radial holes formed at positions facing each other in the radial direction at intervals of 180 degrees in the circumferential direction of the shutter member 23 (cylinder portion 23A). It is configured. The second shutter port 23E is also configured by a total of two radial holes formed at positions facing each other in the radial direction at intervals of 180 degrees in the circumferential direction of the shutter member 23. However, the second shutter port 23E is formed to have a larger hole diameter than the first shutter port 23D, and both are arranged at an interval of 90 degrees in the circumferential direction of the cylindrical portion 23A.

  The third shutter port 23F includes a total of two radial holes formed at positions opposed to each other in the radial direction at intervals of 180 degrees in the circumferential direction of the shutter member 23 in the same manner as the first shutter port 23D described above. Has been. However, the third shutter port 23F has a larger hole diameter than the first shutter port 23D. The fourth shutter port is also constituted by a total of two radial holes formed at positions facing each other in the radial direction at intervals of 180 degrees in the circumferential direction of the shutter member 23. However, the fourth shutter port is formed with a larger hole diameter than that of the third shutter port 23F, and both are arranged at an interval of 90 degrees in the circumferential direction of the cylindrical portion 23A.

  An actuator (not shown) such as an electric motor that rotates the pin member 24 is provided on the protruding end side (the other side in the axial direction) of the rod member 8, and this actuator is connected to the shutter member via the pin member 24. 23 is rotated in the direction of arrow E in FIG. 3 (or the direction opposite to the direction of arrow E) in the shutter insertion hole 10B. Accordingly, the first shutter port 23D or the second shutter port 23E of the shutter member 23 is communicated with or blocked from the guide port 10D of the guide member 10. Further, the third shutter port 23F of the shutter member 23 or the fourth shutter port is communicated with or blocked from the guide port 10E of the guide member 10. At this time, the damping force adjusting valve 22 generates a damping force according to the hole diameter (that is, the passage area) of the shutter ports 23D to 23F.

  Further, the oil liquid as the working fluid flowing through the bypass passage 21 is indicated by an arrow F from the pair of guide ports 10D shown in FIG. 3 into the annular passage portion 25 of the shutter member 23 through the first shutter port 23D, for example. , F flow in opposite directions. However, at this time, the oil liquid is guided along the peripheral surface of the cylindrical mounting portion 23C (that is, around the mounting end portion 24A of the pin member 24) without directly colliding in the directions indicated by arrows F and F. In the annular passage portion 25, a smooth flow is circulated.

  A bush 26 that also serves as a seal member is provided between the guide member 10 and the pin member 24, and this bush 26 contacts the lid portion 23B of the shutter member 23 via a washer 27 in the shutter insertion hole 10B. It is arranged at the position where it touches. The bush 26 supports the pin member 24 so as to be rotatable in the guide member 10 and compensates for a smooth rotation operation of the pin member 24 and the shutter member 23.

  The lid portion 23B of the shutter member 23 is provided with an axial through hole 23G, which keeps the bush 26 in a lubricated state by guiding a part of the oil to the bush 26 side. is there. Since the gap between the pin insertion hole 10A of the guide member 10 and the pin member 24 is sealed by the bush 26, leakage of the oil is prevented.

  A cylindrical body 28 is provided in the shutter insertion hole 10B of the guide member 10 so as to be positioned on the lower side (one side in the axial direction) of the shutter member 23. The cylindrical body 28 constitutes a positioning member that positions the shutter member 23 in the axial direction with a washer 27 (bush 26) provided on the upper side (the other side in the axial direction) of the shutter member 23.

  The rod member 8 of the piston rod 7 is provided with a rebound stopper 30 with a spring 29 interposed between the rod member 8 and the joint member 9 as shown in FIG. The rebound stopper 30 is provided so as to be movable along the outer peripheral surface of the rod member 8 together with the buffer rubber 31. That is, when the piston rod 7 extends greatly, the rebound stopper 30 contacts the lower surface of the rod guide 3 via the buffer rubber 31, and the spring 29 is bent and deformed in the compression direction. Buffered.

  The damping force adjusting type hydraulic shock absorber according to the first embodiment has the above-described configuration, and the operation thereof will be described next.

  When the damping force adjusting hydraulic shock absorber is mounted on the vehicle, the upper end side of the rod member 8 is attached to the vehicle body side of the vehicle, and the attachment eye 32 (see FIG. 1) side provided on the bottom cap 2 is attached to the wheel side. When the vehicle travels, when upward and downward vibrations are generated due to road surface unevenness, the piston rod 7 is displaced from the cylinder 1 so as to expand and contract, and the contraction side damping valve 13, the extension side damping valve 14 and the damping force are displaced. A damping force can be generated by the regulating valve 22 and the like, and the vibration of the vehicle can be buffered.

  That is, in the reduction stroke of the piston rod 7, the piston rod 7 enters the cylinder 1, and the inside of the bottom side oil chamber B becomes higher than the rod side oil chamber A. Flows from the oil passage 6A of the piston 6 into the rod-side oil chamber A through the annular recess 6C and the compression-side damping valve 13 (notch 13A). Further, the oil liquid flowing from the bottom side oil chamber B to the bypass passage 21 (in the shutter insertion hole 10B of the guide member 10) is, for example, the third shutter port 23F of the shutter member 23, the guide port 10E of the guide member 10, and the cylinder. The inflowing oil flows into the intermediate chamber D in the cap member 20 through the notch 19A of the shape spacer 19, and this inflowing oil flows from the oil passage 15A of the sub-piston 15 into the annular recess 15C and the reduction side disk valve 16 (including the notch). Through the rod side oil chamber A.

  On the other hand, in the extension stroke of the piston rod 7, the piston 6 is slid upward in the cylinder 1, and the rod-side oil chamber A becomes higher in pressure than the bottom-side oil chamber B. The oil liquid flows from the oil passage 6B of the piston 6 into the bottom side oil chamber B through the annular recess 6E and the extension side damping valve 14 (notch 14A). Further, the oil liquid flowing from the rod-side oil chamber A into the oil passage 15B, the annular recess 15E and the recess 15G (that is, the bypass passage 21) of the sub-piston 15 passes through the guide port 10D of the guide member 10 and the shutter member 23. It flows into the annular passage 25 via the first shutter port 23D or the second shutter port 23E (see FIG. 3), and enters the bottom side oil chamber B from the shutter insertion hole 10B and the opening end 10C side of the guide member 10. Circulate.

  Here, when the shutter member 23 of the damping force adjusting valve 22 is rotated to connect the first shutter port 23D to the guide port 10D of the guide member 10, the oil liquid flowing through the first shutter port 23D A damping force corresponding to the hole diameter can be generated. Further, when the shutter member 23 is rotated and the second shutter port 23E (see FIG. 3) is communicated with the guide port 10D of the guide member 10, the hole diameter is reduced by the oil liquid flowing through the second shutter port 23E. Accordingly, a relatively soft damping force can be generated.

  By the way, the oil liquid as the working fluid flowing through the bypass passage 21 is indicated by an arrow F, for example, from the pair of guide ports 10D shown in FIG. 3 into the annular passage portion 25 of the shutter member 23 via the first shutter port 23D. , F flow in opposite directions. If such fluid flows collide with each other in the directions indicated by arrows F and F (diameter direction), an unexpected vortex is generated or aeration is generated. Also become.

  Therefore, according to the present embodiment, the damping force adjustment valve 22 is configured by the guide member 10, the shutter member 23, and the pin member 24, and the mounting end 24 </ b> A of the pin member 24 is the first and first of the shutter member 23. 2 It is configured to extend in the axial direction into the shutter member 23 so as to face the shutter ports 23D and 23E in the radial direction. The shutter member 23 includes a cylindrical portion 23A that is rotatably inserted into the shutter insertion hole 10B of the guide member 10, a lid portion 23B that closes an axial end portion of the cylindrical portion 23A, and the lid portion. An attachment end 24A of the pin member 24 extends in the axial direction from 23B into the cylinder portion 23A, and includes a cylindrical attachment portion 23C that is fitted and attached from the lid portion 23B side. The cylindrical mounting portion 23C extends from the outer side of the mounting end portion 24A of the pin member 24 in the axial direction, and is disposed at a position facing the first and second shutter ports 23D and 23E in the radial direction. Yes.

  Thus, for example, the oil liquid flowing in the directions indicated by arrows F and F from the pair of guide ports 10D shown in FIG. 3 into the annular passage portion 25 of the shutter member 23 via the first shutter port 23D is attached to the cylinder. The oil liquid does not directly collide in the directions indicated by the arrows F and F just by striking the outer peripheral surface of the portion 23C, and the annular passage portion 25 in the shutter member 23 (that is, the mounting end 24A of the pin member 24). Flow around).

  For this reason, it is possible to prevent the oil liquid from directly colliding with the cylindrical mounting portion 23C of the shutter member 23 (that is, the peripheral portion of the mounting end portion 24A of the pin member 24), and an unexpected vortex is generated. Or aeration can be prevented, and the occurrence of abnormal noise can be suppressed. Further, the shutter member 23 and the pin member 24 are not subjected to rotational force by the oil liquid flowing in the directions indicated by the arrows F and F. For example, the shutter member 23 and the pin member 24 are extra in the actuator provided on the protruding end side of the piston rod 7 (rod member 8). Can be prevented.

  Moreover, the damping force adjusting valve 22 is constituted by the guide member 10 that forms part of the piston rod 7, and the cylindrical shutter member 23 and the pin member 24 that are inserted into the guide member 10. Since each guide port 10D and each shutter port 23D of the shutter member 23 are provided at positions facing each other at 180 degrees in the circumferential direction, the axial length of the damping force adjusting valve 22 can be shortened. .

  Therefore, according to the present embodiment, the axial length of the damping force adjusting valve 22 can be shortened to shorten the basic length of the shock absorber, and the working fluid can be directly connected inside the damping force adjusting valve 22. The occurrence of abnormal noise and the like can be suppressed.

  In the above-described embodiment, the first shutter port 23D and the second shutter port 23E that are communicated and blocked with respect to each guide port 10D of the guide member 10 are formed, for example, at intervals of 90 degrees in the circumferential direction. Was described as an example. However, the present invention is not limited to this, and for example, only one of the first and second shutter ports may be provided at an interval of 180 degrees, and the other shutter port may be eliminated. Further, another pair of shutter ports having different hole diameters from the first shutter port and the second shutter port may be additionally provided.

  A third shutter port 23F and a fourth shutter port (not shown) are arranged spaced apart from the shutter ports 23D and 23E in the axial direction and communicated with and disconnected from the guide ports 10E of the guide member 10. The same change as the first and second shutter ports described above can be made.

  Moreover, in the said embodiment, the case where the outer shell in the single cylinder type damping force adjustment type hydraulic shock absorber was formed using the cylindrical cylinder 1 was described as an example. However, the present invention is not limited to this. For example, the present invention may be applied to a double-cylinder damping force adjusting shock absorber including an outer cylinder and an inner cylinder.

  On the other hand, in the above embodiment, the case where an actuator such as an electric motor that rotates the pin member 24 is provided on the protruding end side (the other side in the axial direction) of the rod member 8 has been described as an example. However, the present invention is not limited to this, and an actuator such as an electric motor that rotates the pin member of the damping force adjusting valve may be provided inside the cylinder (for example, in the piston rod). In this case, it is possible to improve the mountability of the damping force adjustment type shock absorber to the vehicle, and the actuator is not protruded and mounted in the engine room, which is space-saving and safe. Further, the pin member of the damping force adjusting valve does not necessarily need to be rotated using an actuator such as an electric motor, and may be configured to rotate the shutter member via the pin member by manual operation, for example.

  Furthermore, in the above-described embodiment, the damping force adjusting hydraulic shock absorber as a damping force adjusting shock absorber provided in a vehicle such as an automobile has been described as an example. However, the present invention is not limited to this. For example, the present invention can also be applied to a damping force adjustment type shock absorber used for various machines, buildings, and the like which are vibration sources.

1 cylinder 6 piston 6A, 6B oil passage (main passage)
7 piston rod 8 rod member 9 joint member 10 guide member 10A pin insertion hole 10B shutter insertion hole 10D guide port 13 compression side damping valve (reduction side damping force generation mechanism)
14 Extension side damping valve (Extension side damping force generation mechanism)
15 Sub piston 16 Reduction side disk valve 17 Extension side disk valve 20 Cap member 21 Bypass passage 22 Damping force adjustment valve 23 Shutter member 23A Cylinder part 23B Lid part 23C Cylindrical attachment part 23D, 23E Shutter port 24 Pin member 24A Attachment end part (Mounting end side)
25 Annular passage A Rod side oil chamber (rod side chamber)
B Bottom side oil chamber (bottom side chamber)
C Gas chamber D Intermediate chamber

Claims (3)

A cylinder filled with a working fluid; a piston that is movably fitted in the cylinder and defines two chambers, a rod side chamber and a bottom side chamber; and one end side fixed to the piston and the other end side A piston rod protruding outside the cylinder; a main passage formed in the piston for communicating the rod side chamber and the bottom side chamber; and located in the rod side chamber and provided in the piston rod and non-sliding in the cylinder A sub-piston disposed in a state, a bypass passage formed in the sub-piston and the piston rod, bypassing the main passage and communicating between the rod-side chamber and the bottom-side chamber, and a passage area of the bypass passage In a damping force adjustment type shock absorber comprising a damping force adjustment valve that variably adjusts the damping force by changing,
The damping force adjusting valve is
A cylindrical guide member comprising a cylindrical body forming a part of the piston rod and having a plurality of radial guide ports forming a part of the bypass passage on a peripheral wall;
A shutter member rotatably provided in the guide member and having a plurality of shutter ports that are communicated with and blocked from the guide port;
A pin member that is inserted through the piston rod to rotate the shutter member.
The guide ports and the shutter ports are provided at positions facing each other at 180 degrees in the circumferential direction,
A damping force adjusting type shock absorber, wherein the pin member is arranged at a position where an attachment end side fixedly attached to the shutter member is opposed to the shutter port in a radial direction.   The shutter member includes a cylindrical portion that is rotatably inserted into the guide member, a lid portion that closes an axial end portion of the cylindrical portion, and an axial direction extending from the lid portion into the cylindrical portion. The attachment end side of the pin member has a cylindrical attachment portion that is fitted and attached from the lid portion side, and communicates with the shutter port between the cylindrical attachment portion and the cylindrical portion. The damping force adjusting type shock absorber according to claim 1, wherein an annular passage portion constituting a part of the bypass passage is provided.   The said working fluid which distribute | circulates the said bypass channel becomes a structure which flows along the attachment end side circumference | surroundings of the said pin member, when it flows in in the said shutter member via the said shutter port from the said guide port. A damping force adjustable shock absorber as described in 1.

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