JP6246425B1 - Shock absorber - Google Patents

Abstract

Provided is a shock absorber (10) capable of suppressing an impact received by an occupant while securing an impact force to be received. The shock absorber (10) includes a pair of tubes (11, 12) that slide relative to each other, a hollow rod (16) provided on the tube (11), and a first disposed on the inner periphery of the tube (12). A valve seat (33) and a second valve seat (41), and a first valve body (35) and a second valve body (39), the first valve body (35) of the hollow rod (16) The first valve seat (33) can be seated on the second valve seat (41) in a state where a gap is provided between the outer periphery and the second valve body (39) while being biased downward in the axial direction. ).

Description

  The present invention relates to a shock absorber, and more particularly to a shock absorber provided with an oil lock device that receives impact force.

  In a shock absorber mainly applied to the front fork of a motorcycle, an oil lock device that receives the impact force by closing the oil at the lower end or limit part of the stroke to prevent bottoming when a large impact force is input. (For example, Patent Document 1). In the oil lock device for a shock absorber disclosed in Patent Document 1, a lower valve that forms a flow path between the outer periphery of the hollow rod is disposed between the hollow rod and the inner tube. When a large impact force is input, the lower valve throttles the flow path, closes the oil, and receives the impact force.

JP 2010-151310 A

  However, in the technique disclosed in Patent Document 1, there is a demand for suppressing the impact received by the occupant while ensuring the impact force (maximum load) to be received.

  The present invention has been made to meet the above-described demand, and an object of the present invention is to provide a shock absorber capable of suppressing an impact received by an occupant while ensuring a maximum load that can be received.

In order to achieve this object, the shock absorber of the present invention has an inner tube disposed on the vehicle body side and an outer tube disposed on the wheel side. The outer tube is in sliding contact with the outer periphery of the inner tube. A hollow rod is provided at the bottom of the outer tube. A first valve seat and a second valve seat are disposed in the inner circumference of the inner tube in the axial direction of the inner tube in order from the wheel side to the vehicle body side. A first valve body and a second valve body, each seatable on the second valve seat and the first valve seat, are provided, and the first valve body and the second valve body are arranged in order from the wheel side to the vehicle body side in the axial direction. . A lower oil chamber surrounded by an outer tube, an inner tube, and a hollow rod is formed on the wheel side of the first valve body and the second valve body. The first valve body can be seated on the second valve seat with a clearance from the outer periphery of the hollow rod, and the second valve body is urged downward in the axial direction. It can adhere to the seating surface of the seat. In the pressure side stroke in which the inner tube enters the lower oil chamber, when the lower oil chamber becomes higher than a predetermined pressure, the second valve body opens with the first valve body seated on the second valve seat.

  According to the shock absorber of the first aspect, the maximum load can be secured in a state where the first valve body is seated on the second valve seat. When the second valve body is opened in this state, the impact received by the occupant can be suppressed. Therefore, there is an effect that the impact received by the occupant can be suppressed while ensuring the maximum load.

It is a half sectional view of the shock absorber in a 1st embodiment. It is sectional drawing of an oil lock apparatus. It is sectional drawing of the oil lock apparatus of the most compressed state. It is sectional drawing of the oil-lock apparatus at the time of the reversal from the most compressed state to the expansion side stroke. It is sectional drawing of the buffer in 2nd Embodiment. It is sectional drawing of the oil lock apparatus at the time of a compression side stroke. It is sectional drawing of the buffer in 3rd Embodiment. It is sectional drawing of the buffer in 4th Embodiment. It is an exploded view of the part which comprises an oil-lock apparatus among shock absorbers. It is sectional drawing of the buffer in 5th Embodiment. It is an exploded view of the part which comprises an oil-lock apparatus among shock absorbers.

(First embodiment)
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, the shock absorber 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a half sectional view of a shock absorber 10 according to the first embodiment. The shock absorber 10 is a device mainly applied to a front fork of a motorcycle. An inner tube 12 connected to the vehicle body side is slidably inserted into an outer tube 11 connected to the wheel side. A dust seal 13 and an oil seal 14 are arranged at the opening end of the outer tube 11 into which the inner tube 12 is inserted.

  A bolt 15 is inserted into the bottom of the outer tube 11, and a hollow rod 16 (hollow rod) is fixed along the outer tube 11 by the bolt 15. The hollow rod 16 has an enlarged upper end portion and forms a partition wall portion 17 that is in sliding contact with the inner periphery of the inner tube 12. In the present embodiment, a ring-shaped check valve 18 (described later) is provided in a groove provided on the outer periphery of the partition wall portion 17. The check valve 18 functions as a piston ring and is in sliding contact with the inner periphery of the inner tube 12.

  The hollow rod 16 has oil holes 19 and 20 penetrating in the radial direction at the lower part and the upper part, respectively. The oil holes 19 are formed at a plurality of locations in the axial direction and the circumferential direction of the hollow rod 16. In the shock absorber 10, a coil spring 22 is interposed between the spring seat 21 that closes the upper end portion of the inner tube 12 and the upper end surface of the partition wall portion 17. The coil spring 22 is a suspension spring that biases the hollow rod 16 and the inner tube 12 in the extending direction.

  The hollow rod 16 includes an internal oil reservoir chamber 23 for storing hydraulic oil, and an oil chamber (a lower oil chamber 25 and an upper oil chamber 26) formed between the outer tube 11 and the inner tube 12 and the hollow rod 16. Partition. The oil reservoir chamber 23 is in contact with the air chamber 24 through a free interface of hydraulic oil that exists above the upper end (partition wall portion 17) of the hollow rod 16. An oil lock device 30 that moves forward and backward to the lower oil chamber 25 and the upper oil chamber 26 is disposed on the inner periphery of the lower end portion of the inner tube 12.

  The oil hole 19 communicates the lower oil chamber 25 and the upper oil chamber 26 with the oil reservoir chamber 23, and the oil hole 20 communicates with the upper oil chamber 26 and the oil reservoir chamber 23. In the inner tube 12, a rebound spring 27 that urges the hollow rod 16 and the inner tube 12 in the compression direction at the time of maximum extension is disposed between the oil lock device 30 and the partition wall portion 17.

  The check valve 18 opens in the pressure side stroke, and causes the hydraulic oil in the oil reservoir chamber 23 existing above the partition wall portion 17 to flow into the upper oil chamber 26. The check valve 18 closes in the extension side stroke, and does not allow the hydraulic oil in the upper oil chamber 26 to flow into the oil reservoir chamber 23 that exists above the partition wall portion 17.

  The oil lock device 30 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the oil lock device 30. In FIG. 2, a part of the shock absorber 10 illustrated in the axial direction and a part symmetrical with respect to the axis are omitted.

  The oil lock device 30 includes a restriction member 31, a first valve seat 33, a second valve seat 41, and a restriction member 46 fixed to the inner tube 12 by caulking in order from the wheel side to the vehicle body side in the axial direction of the inner tube 12. Are lined up. The regulating members 31, 46, the first valve seat 33, and the second valve seat 41 are formed in a cylindrical shape that forms an annular flow path between the outer periphery of the hollow rod 16. The regulating members 31, 46, the first valve seat 33 and the second valve seat 41 are disposed on the lower side in the axial direction than the partition wall portion 17 of the hollow rod 16. In the first valve seat 33, a first valve body 35 and a second valve body 39 are disposed on the inner side in the radial direction.

  The restriction member 31 is an annular member for restricting the movement of the first valve body 35 in the axial direction, and the stopper 32 protrudes radially inward from a plurality of locations in the circumferential direction. Since the stopper 32 is arranged at intervals in the circumferential direction, a flow path between the regulating member 31 and the hollow rod 16 is ensured. Since the stopper 32 is disposed with a gap in the axial direction from the first valve body 35, the axial movement of the first valve body 35 is allowed until the first valve body 35 contacts the stopper 32.

  The first valve body 35 is an annular member that can be seated on the second valve seat 41, and an annular first flow path 36 is formed between the first valve body 35 and the hollow rod 16. In the present embodiment, the first valve body 35 is made of a synthetic resin. The first valve body 35 moves in the axial direction along the outer periphery of the hollow rod 16 between the regulating member 31 and the second valve body 39. The first valve body 35 may be provided with a plurality of centering protrusions (not shown) that protrude inward in the radial direction and contact the hollow rod 16.

  The first valve body 35 forms an annular second flow path 37 between the outer periphery of the first valve body 35 and the first valve seat 33. The first valve body 35 is provided with a chamfered portion 38 over the entire circumference at a corner of the outer circumference closer to the regulating member 31. The chamfered portion 38 is a part for taking a corner of the outer periphery of the first valve body 35 and making the corner a square or a round surface. The chamfered portion 38 formed on the outer periphery of the first valve body 35 can facilitate the operation oil to flow into the second flow path 37.

  When the first valve body 35 moves relatively upward with respect to the first valve seat 33, the upper end face comes into contact with the lower surface 39 a of the second valve body 39 without any gap and seals. In the present embodiment, the second valve body 39 is also a part of the second valve seat 41. From the state in which the first valve body 35 is in contact with the second valve body 39, the first valve body 35 is relatively moved downward to move away from the second valve body 39, and the first valve body 35 is moved to the stopper 32 of the regulating member 31. When it abuts, a second gap 51 (see FIG. 4) is formed between the upper end surface and the second valve body 39. The cross-sectional area of the second gap 51 is larger than the cross-sectional area of the first flow path 36. The first flow path 36 formed by the first valve body 35 is a pressure side throttle flow path.

  The first valve seat 33 is a cylindrical member in which a second flow path 37 is formed between the first valve body 35 and an annular first seat surface 34 is formed on the inner periphery. The entire circumference of the lower surface 39a of the second valve body 39 is in line contact with the first seat surface 34 when the second valve body 39 is in the closed position. The second flow path 37 has a cross-sectional area larger than that of the first flow path 36.

  The 2nd valve body 39 is an annular member which can be seated on the 1st valve seat 33, and closes the 2nd channel 37 so that opening is possible by bending deformation. In the present embodiment, the second valve body 39 is formed of a thin metal plate. The second valve body 39 forms an annular first gap 40 between the inner periphery of the second valve body 39 and the outer periphery of the hollow rod 16. The cross-sectional area of the first gap 40 is larger than the cross-sectional area of the first flow path 36. The second valve body 39 may be provided with a plurality of centering protrusions (not shown) protruding inward in the radial direction and contacting the hollow rod 16.

  The second valve seat 41 is a cylindrical member that regulates the position of the second valve body 39 and accommodates the third valve body 48 inside in the radial direction. As for the 2nd valve seat 41, the support part 42 protrudes toward the axial direction lower side from the several places of the axial direction lower end surface. The support portion 42 has a tip that abuts on the upper surface of the second valve body 39 and serves as a fulcrum for bending the second valve body 39. The support portion 42 is disposed at a position facing the first valve body 35 in the axial direction across the second valve body 39. Since the support portions 42 are arranged at intervals in the circumferential direction, the fourth flow path 44 is formed between the second valve body 39 and the end face of the second valve seat 41.

  Since the lower surface 39a of the second valve body 39 against which the support portion 42 is abutted is located below the position of the first seat surface 34 of the first valve seat 33 in the axial direction, the first seat surface 34 and the support The part 42 holds the second valve body 39 in a deformed state. The second valve body 39 is urged in the direction in which the second flow path 37 is closed (the lower side in the axial direction) by pre-deflection by the first seat surface 34 and the support portion 42. The second valve body 39 bends and opens the second flow path 37 when the pressure in the lower oil chamber 25 increases.

  The second valve seat 41 holds the second valve body 39 in a state of being bent by the support portion 42 and the first seat surface 34 of the first valve seat 33. Thereby, the second valve seat 41 arranges the second valve body 39 on the inner side in the radial direction than the first seat surface 34 of the first valve seat 33. Since the 2nd valve body 39 is arrange | positioned at the axial direction upper side of the 1st valve body 35, when the 1st valve body 35 exists in a closed state, the 2nd seat surface which the 1st valve body 35 makes a line contact to the perimeter As described above, the lower surface 39a of the second valve body 39 can be used. Since the lower surface 39a of the second valve body 39 is the second seat surface, each component can be arranged compactly.

  The second valve seat 41 forms a third flow path 43 between the outer periphery of the hollow rod 16. The cross-sectional area of the third flow path 43 is larger than the cross-sectional area of the first flow path 36. As for the 2nd valve seat 41, the 3rd seat surface 45 (upper seat surface) which expands as it goes to the upper side of an axial direction is formed in the inner periphery. A third valve body 48 is disposed between the third seat surface 45 and the restriction member 46.

  The restricting member 46 is an annular member for restricting the movement of the third valve body 48 in the axial direction, and the stopper 47 protrudes radially inward from a plurality of locations in the circumferential direction. Since the stoppers 47 are arranged at intervals in the circumferential direction, a flow path between the regulating member 46 and the hollow rod 16 is ensured. Since the stopper 47 is disposed with a gap in the axial direction from the third valve body 48, the third valve body 48 is allowed to move in the axial direction until it contacts the stopper 47.

  The third valve body 48 is an annular member that forms an annular inner flow path 49 between itself and the hollow rod 16, and is made of a synthetic resin in the present embodiment. The third valve body 48 moves in the axial direction along the outer periphery of the hollow rod 16 between the regulating member 46 and the third seat surface 45. The third valve body 48 may be provided with a plurality of centering protrusions (not shown) protruding inward in the radial direction and in contact with the hollow rod 16. The third valve body 48 forms an annular outer flow path 50 between the outer periphery of the third valve body 48 and the second valve seat 41.

  When the third valve body 48 moves relatively downward with respect to the second valve seat 41, the outer peripheral surface of the third valve body 48 is in line contact with the third seat surface 45 without any gap and sealed, and the outer flow path 50 is sealed. Close. From the state in which the third valve body 48 is in contact with the third seat surface 45, the third valve body 48 is relatively moved upward to move away from the third seat surface 45, and the third valve body 48 hits the stopper 47 of the restriction member 46. Then, the inner channel 49 and the outer channel 50 are formed. The cross-sectional area of the outer flow path 50 is larger than the cross-sectional area of the inner flow path 49. The inner flow path 49 formed by the third valve body 48 becomes an expansion side throttle flow path.

  The shock absorber 10 (see FIG. 1) cushions the impact received by the wheels by the coil spring 22 and the air spring of the air chamber 24, and generates expansion and contraction vibration accompanying absorption of the impact in the lower oil chamber 25 and the upper oil chamber 26. Suppressed by damping force.

  The damping action of the shock absorber 10 will be described with reference to FIGS. 3 is a cross-sectional view of the oil lock device 30 in the most compressed state, and FIG. 4 is a cross-sectional view of the oil lock device 30 at the time of reversal from the most compressed state to the extension side stroke. In FIGS. 3 and 4, illustration of a part of the shock absorber 10 in the axial direction and a part symmetrical with respect to the axis are omitted.

(Pressure side stroke)
As shown in FIG. 2, in the compression side stroke, when the inner tube 12 enters the lower oil chamber 25, the volume of the upper oil chamber 26 increases and the pressure decreases. The check valve 18 (see FIG. 1) is opened, and the hydraulic oil in the oil reservoir chamber 23 above the partition wall portion 17 flows into the upper oil chamber 26 through the check valve 18. The hydraulic oil corresponding to the volume of entry into the lower oil chamber 25 of the inner tube 12 flows from the lower oil chamber 25 into the oil reservoir chamber 23 inside the hollow rod 16 through the plurality of oil holes 19. The compression side damping force is generated by the plurality of oil holes 19.

  Since the volume of the lower oil chamber 25 is reduced and the pressure in the lower oil chamber 25 is increased, the first valve body 35 moves upward to contact the second valve body 39 and the third valve body 48 moves upward. Then it abuts against the regulating member 46. The hydraulic oil in the lower oil chamber 25 flows into the upper oil chamber 26 through the first flow path 36, the first gap 40, the third flow path 43, and the outer flow path 50. A compression side damping force based on the throttle resistance of the first flow path 36 due to the shape of the inner periphery of the first valve body 35 is generated.

  As shown in FIG. 3, when the first valve body 35 sequentially closes the plurality of oil holes 19 and enters the final stage of the compression side stroke (stroke limit portion), the hydraulic oil in the lower oil chamber 25 flows into the first flow path. After passing through 36, it flows into the upper oil chamber 26 through the first gap 40, the third flow path 43 and the outer flow path 50. Alternatively, the hydraulic oil in the lower oil chamber 25 passes through the first flow path 36 and then flows into the oil reservoir chamber 23 through the first gap 40, the third flow path 43 and the oil hole 19. As a result, the flow area of the hydraulic oil from the lower oil chamber 25 to the upper oil chamber 26 or the oil reservoir chamber 23 is reduced by the closed oil hole 19, so that the hydraulic oil in the lower oil chamber 25 is blocked. The oil lock is activated. Since the compression side damping force increases, the bottom of the inner tube 12 can be prevented.

  The damping force (load) by the first flow path 36 (pressure side throttle flow path) increases in proportion to almost the square of the speed at which the inner tube 12 enters the lower oil chamber 25. Accordingly, when the speed at which the inner tube 12 enters the lower oil chamber 25 is fast, the load increases rapidly, so that the impact received by the occupant when the lower oil chamber 25 enters the oil lock state also increases. On the other hand, the impact force (maximum load) received by the oil lock device 30 when the speed at which the inner tube 12 enters the lower oil chamber 25 is relatively slow can be secured by the first flow path 36.

  In addition to the first flow path 36, the oil lock device 30 is provided with a second flow path 37 that communicates the lower oil chamber 25 and the upper oil chamber 26 in parallel with the first flow path 36. The second flow path 37 is closed by a second valve body 39 that bends and deforms when the pressure in the lower oil chamber 25 increases. When the second valve body 39 is bent and deformed to open the second flow path 37, the hydraulic oil in the lower oil chamber 25 flows into the fourth flow path 44 through the second flow path 37. The damping force (load) due to the second flow path 37 in which the opening area changes due to the deformation of the second valve body 39 is proportional to approximately the 2/3 power of the speed at which the inner tube 12 enters the lower oil chamber 25. To increase.

  As a result, the damping forces of the first channel 36 and the second channel 37 are combined with the damping forces of the first channel 36 and the second channel 37, and the inner tube 12 enters the lower oil chamber 25. Can be proportional to speed. Accordingly, the oil lock device 30 prevents bottoming both when the speed at which the inner tube 12 enters the lower oil chamber 25 is fast and slow, and particularly when the speed at which the inner tube 12 enters the lower oil chamber 25 is fast. A sudden increase in load can be suppressed. Therefore, the impact can be reduced.

  The oil lock device 30 is disposed at a position where the third valve body 48 cannot completely close the oil hole 19 when the first valve body 35 is positioned below the hollow hole 16 relative to the oil hole 19. ing. Therefore, the oil pressure in the oil reservoir 23 reaches the upper portion of the third valve body 48 via the third flow path 43.

(Extension process)
As shown in FIG. 4, when the compression is reversed from the most compressed state to the extension side stroke, the first valve body 35 is pushed down by the differential pressure between the oil pressure in the oil reservoir chamber 23 and the oil pressure in the lower oil chamber 25, and the second valve body The first valve body 35 abuts against the regulating member 31 away from 39. A second gap 51 is formed between the second valve body 39 and the first valve body 35. The hydraulic oil in the oil reservoir 23 flows into the lower oil chamber 25 through the second gap 51 and the second flow path 37. Since the negative pressure in the lower oil chamber 25 is quickly eliminated, it is possible to prevent the occurrence of a missing sound when reversing from the most compressed state to the extension side stroke.

  When the inner tube 12 retreats from the lower oil chamber 25, the hydraulic oil in the upper oil chamber 26 flows through the oil hole 20 formed in the hollow rod 16 and flows into the oil reservoir chamber 23 inside the hollow rod 16. An extension side damping force is generated by the oil hole 20. The hydraulic oil corresponding to the retraction volume from the lower oil chamber 25 of the inner tube 12 is supplied from the oil reservoir chamber 23 inside the hollow rod 16 through the oil hole 19.

  Since the volume of the upper oil chamber 26 is reduced and the pressure of the upper oil chamber 26 is increased, the third valve body 48 is moved downward relative to the second valve seat 41, and the third valve body 48 is moved to the second position. It contacts the third seat surface 45 of the valve seat 41 without a gap. The first valve body 35 remains in contact with the regulating member 31. The hydraulic oil in the upper oil chamber 26 flows into the lower oil chamber 25 through the inner flow path 49, the third flow path 43, the first gap 40, the second gap 51, and the second flow path 37. The extension side damping force based on the throttle resistance of the inner flow path 49 due to the shape of the inner periphery of the third valve body 48 is generated.

  As described above, the oil lock device 30 includes the first valve seat 33, the second valve seat 41, the first valve body 35, and the second valve body 39. A cylindrical first valve seat 33 disposed on the outer periphery of the hollow rod 16 forms a second flow path 37 between the first valve body 35 and the first valve body 35. A cylindrical second valve seat 41 arranged on the upper side of the first valve seat 33 and on the outer periphery of the hollow rod 16 forms a third flow path 43 communicating with the first flow path 36 between the hollow rod 16. . The support portion 42 of the second valve seat 41 has a fourth flow path 44 communicating with the third flow path 43 in a state where the second valve body 39 is sandwiched between the second valve body 39 and the first valve body 35. Form between.

  The second valve body 39 forms a first gap 40 between the hollow rod 16 and a cross-sectional area wider than the cross-sectional area of the first flow path 36. The third flow path 43 and the fourth flow path 44 have a larger cross-sectional area than the cross-sectional area of the first flow path 36, and when the second valve body 39 opens the second flow path 37, the second flow path 37 and the fourth flow path The road 44 communicates. Therefore, the structure of the oil lock device 30 can be simplified.

  The first seat surface 34 of the first valve seat 33 and the support portion 42 of the second valve seat 41 hold the second valve body 39 in a deformed state. As a result, the pressure of the lower oil chamber 25 that opens the second flow path 37 can be adjusted by pre-deflection of the second valve body 39 by the first valve seat 33 and the support portion 42.

  Since the second valve body 39 is bent by the first valve seat 33 and the support portion 42, even if the first valve body 35 moves in the axial direction and separates from the second valve body 39, the second valve body 39 The valve body 39 is held at the same position. Therefore, the set pressure at which the second valve body 39 is deformed can be prevented from changing due to the change in the position of the second valve body 39.

  In the second valve body 39, when the lower oil chamber 25 is in the oil-locked state at the maximum compression, the pressure (bending load) of the lower oil chamber 25 is applied, but in the normal stroke region (when not in the oil-locked state) Only a small bending load by the one valve seat 33 and the support part 42 is applied. When in the oil lock state, the first valve body 35 presses the second valve body 39, but the support portion 42 faces the first valve body 35 across the second valve body 39, so the first valve body Bending load due to 35 and the support portion 42 does not occur in the second valve body 39. That is, since the second valve body 39 is only subjected to a bending load due to the pressure in the lower oil chamber 25 when in the oil lock state, the durability of the second valve body 39 can be ensured.

  The support portion 42 serves as a fulcrum for the second valve body 39 to bend and deform, and the second valve body 39 comes into line contact with the first seat surface 34 by the restoring force of the deformation. The magnitude of the pre-deflection is set by the axial distance between the first seat surface 34 and the tip of the support portion 42. The lower oil chamber 25 in which the second valve body 39 is deformed to open the second flow path 37 depending on the thickness and material of the second valve body 39 and the radial distance between the support portion 42 and the first seat surface 34. The pressure can be set. Therefore, the upper limit value of the pressure in the lower oil chamber 25 can be easily set.

  When the pressure in the lower oil chamber 25 is increased, the second valve body 39 is opened to release the pressure in the lower oil chamber 25 when in the oil lock state. The maximum pressure in the lower oil chamber 25 can be lowered. As a result, the strength of the outer tube 11 and the hollow rod 16 constituting the lower oil chamber 25 can be set low.

  Since the second seat surface (the lower surface 39a of the second valve element 39) and the third seat surface 45 are provided above and below the second valve seat 41, the valve seats having the second seat surface and the third seat surface are provided. Compared with the case of providing two, the number of parts can be reduced. Since the lower surface 39a of the second valve body 39 is the second seat surface in close contact with the first valve body 35, the oil lock device 30 in which two valve seats and three valve bodies are arranged between the regulating members 31 and 46. (Piston) can be made compact.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. In the first embodiment, the case where the regulating member 31 regulates the movement of the first valve body 35 toward the lower oil chamber 25 has been described. On the other hand, in the second embodiment, a case will be described in which the regulating member 31 is omitted and the first valve body 62 is elastically supported by the spring 65 instead. In addition, about the part same as the part demonstrated in 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted.

  FIG. 5 is a cross-sectional view of the shock absorber 60 according to the second embodiment, and FIG. 6 is a cross-sectional view of the oil lock device 61 during the compression side stroke. 5 and 6, illustration of a part of the shock absorber 60 in the axial direction and a part symmetrical with respect to the axis are omitted.

  As shown in FIGS. 5 and 6, the oil lock device 61 of the shock absorber 60 includes a first valve seat 33, a second valve seat 41, and a regulating member 46 that are fixed by crimping to the inner tube 12. They are arranged in the axial direction. The first valve body 62 includes a cylindrical tube portion 63 that extends in the axial direction along the hollow rod 16 from the inside of the end surface in the axial direction. The first valve body 62 forms an annular first flow path 64 between the hollow rod 16 and the first valve body 62. As for the 1st valve body 62, the cylinder part 63 is engage | inserted by the upper end of the spring 65. FIG. The spring 65 is a coil spring disposed around the hollow rod 16, and the lower end is fixed to the lower portion of the hollow rod 16.

  Since the first valve body 62 is elastically supported in the lower oil chamber 25 by the spring 65 in a state of being separated from the inner tube 12, the first valve body 62 is attached to the second valve body 39 as the inner tube 12 enters the lower oil chamber 25. It is pushed and moves downward in the axial direction along the outer periphery of the hollow rod 16. The spring 65 has a free length so that the first valve body 62 is positioned above the lowest oil hole 19 in a state where the first valve body 62 and the second valve body 39 are not in contact with each other. Is set. The spring 65 elastically supports the first valve body 62 at a position where at least the first valve seat 33 and the first valve body 62 do not overlap in the radial direction in a normal stroke region (when not in an oil lock state).

  The first valve body 62 may be provided with a plurality of centering protrusions (not shown) that protrude inward in the radial direction and contact the hollow rod 16. When the first valve body 62 enters the inside of the first valve seat 33 in the radial direction, an annular second flow path 37 is formed between the first valve body 62 and the first valve seat 33.

  Since the first valve body 62 is supported by the spring 65 in the oil lock device 61, the first valve body 62 is not brought into contact with the second valve body 39 in the normal stroke range (when not in the oil lock state). Can be. In the compression side stroke, the hydraulic oil in the lower oil chamber 25 flows into the upper oil chamber 26 through the inside of the first valve seat 33, the first gap 40, the third flow path 43, and the outer flow path 50. Since the first valve body 62 is retracted from the first valve seat 33, it is possible to prevent the hydraulic oil from flowing into the upper oil chamber 26 in the compression side stroke. As a result, it is possible to generate a stable extension side damping force in the extension side stroke using the hydraulic oil filled in the upper oil chamber 26 in the compression side stroke.

  When the oil lock device 61 is reversed from the most compressed state to the extension side stroke, the first valve body 62 is pushed down by the differential pressure between the oil pressure in the oil reservoir chamber 23 and the oil pressure in the lower oil chamber 25, and the second valve body 39. Get away from. Since the oil lock device 61 does not include the regulating member 31 (see FIG. 4), the second gap 51 (see FIG. 4) formed between the second valve body 39 and the first valve body 35 can be enlarged. . The second valve body 39 closes the second flow path 37, but the hydraulic oil in the upper oil chamber 26 and the oil reservoir chamber 23 flows into the lower oil chamber 25 through the inside of the first valve seat 33. Since the negative pressure in the lower oil chamber 25 is quickly eliminated, it is possible to prevent the occurrence of a missing sound when reversing from the most compressed state to the extension side stroke.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. 3rd Embodiment demonstrates the case where the displacement control part 75 is formed in the lower end surface of the 2nd valve seat 73. FIG. In addition, about the part same as the part demonstrated in 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 7 is a cross-sectional view of the shock absorber 70 in the third embodiment. In FIG. 7, a part of the shock absorber 70 illustrated in the axial direction and a part symmetrical with respect to the axis are omitted.

  As shown in FIG. 7, in the oil lock device 71 of the shock absorber 70, a first valve seat 72 and a second valve seat 73 fixed by crimping to the inner tube 12 are arranged in the axial direction of the inner tube 12. As for the 2nd valve seat 73, the support part 74 protrudes toward the downward direction of an axial direction from several places of the axial lower end surface. In the second valve seat 73, a displacement restricting portion 75 is formed in a radially outer portion of the support portion 74 on the lower end surface in the axial direction.

  The displacement restricting portion 75 is a part that restricts the maximum displacement of the second valve body 39 when the peripheral edge of the deformed second valve body 39 abuts. The distance L in the axial direction from the tip of the support portion 74 (the lower end in the axial direction) to the displacement restricting portion 75 is equal to or less than the deformation amount of the second valve body 39 in which the yield stress is generated in the second valve body 39. Is set. By providing the displacement restricting portion 75 in the second valve seat 73, it is possible to prevent the second valve body 39 from being plastically deformed when an excessive load is input to the second valve body 39. The maximum value of elastic deformation at this time is the maximum displacement.

  The second valve seat 73 has a groove 76 that is recessed in the axial direction from the displacement regulating portion 75 on the lower end surface in the axial direction. A plurality of the groove portions 76 are radially formed between the support portions 74. The groove 76 communicates the second flow path 37 and the third flow path 43 with the second valve body 39 open. Since the displacement restricting portion 75 is present, the fourth flow path 44 may be narrowed when the second valve body 39 is bent. However, since the groove portion 76 is formed, the second valve body 39 becomes the displacement restricting portion 75. The fourth flow path 44 can be secured even in the contact state. As a result, even when an excessive load that causes the second valve body 39 to come into contact with the displacement regulating portion 75 is input, it is possible to prevent plastic deformation of the second valve body 39 while suppressing the impact received by the occupant.

  In addition, protrusions and ridges that are scattered in the circumferential direction are provided on the upper surface of the second valve body 39, and when an excessive load is input and the protrusions contact the displacement restricting portion 75, the space between the protrusions is If the hydraulic oil flows, the fourth flow path 44 can be secured. However, the provision of the protrusions or the like on the second valve body 39 makes it difficult to design the second valve body 39 in consideration of mechanical characteristics such as a load deflection curve and to ensure the stability of the operation of the second valve body 39. There is a fear. On the other hand, according to the third embodiment, since the groove portion 76 for securing the fourth flow path 44 is provided in the second valve seat 73, it is easy to ensure the design and operation stability of the second valve body 39. it can.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS. FIG. 8 is a cross-sectional view of the shock absorber 80 in the fourth embodiment, and FIG. In FIG. 8, illustration of the outer tube 11 and the hollow rod 16 and a part of the inner tube 12 are omitted for easy understanding. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted.

  As shown in FIG. 8, the shock absorber 80 is arranged on the inner periphery of the lower end portion of the inner tube 12 in order from the bottom to the top in the axial direction, the regulating member 31, the first valve seat 81, the second valve seat 87, and the regulating member 46. Is arranged. The second valve body 39 is disposed between the first valve seat 81 and the second valve seat 87, the first valve body 35 is disposed between the regulating member 31 and the second valve body 39, and the regulating member 46 A third valve body 48 is disposed between the second valve seat 87 and the second valve seat 87. The regulating member 31, the first valve seat 81, the second valve seat 87, and the regulating member 46 are configured such that the step 94 formed on the inner periphery of the inner tube 12 and the tip (lower end) of the inner tube 12 are bent inward. And the position in the axial direction is restricted.

  As shown in FIG. 9, the first valve seat 81 includes an annular first portion 82 and an axially upper portion from the radially outer portion of the end surface of the first portion 82 on the second valve body 39 side. And an annular second portion 83 that protrudes from the center. In the first valve seat 81, a first seat surface 84 on which the second valve body 39 is seated is formed on the inner periphery of the boundary between the first portion 82 and the second portion 83. The second portion 83 includes an inner peripheral surface 85 that continues to the outer side in the radial direction of the first seat surface 84, and a first contact portion 86 that continues from the inner peripheral surface 85 to the outer side in the radial direction. The first contact portion 86 is located at the tip of the second portion 83 in the axial direction. Since the difference between the inner diameter of the second part 83 and the inner diameter of the first part 82 can be made the size of the first seat surface 84 provided on the inner periphery of the first valve seat 81, the thickness of the second part 83 can be reduced. The strength of the second part 83 can be ensured by securing.

  The second valve seat 87 has an annular shape that protrudes downward in the axial direction from a third portion 88 formed in an annular shape and a radially inner portion of the end surface of the third portion 88 on the second valve body 39 side. 4th part 89 of this invention. The fourth portion 89 is provided with a support portion 90 that presses the radially inner upper surface of the second valve body 39. The second valve seat 87 has a second contact portion 91 formed on the outer periphery of the boundary between the third portion 88 and the fourth portion 89. The outer peripheral surface 92 of the fourth portion 89 is continuous with the radially inner side of the second contact portion 91. The third portion 88 has a third seat surface 93 on the inner periphery on which the third valve body 48 is seated. Since the support portion 90 that presses the upper surface in the radial direction of the second valve body 39 is provided on the fourth portion 89 of the second valve seat 87 inserted inside the second portion 83 of the first valve seat 81, The thickness of the fourth part 89 can be secured by securing the thickness of the fourth part 89.

  In the present embodiment, the inner diameter of the inner peripheral surface 85 of the second part 83 is set smaller than the outer diameter of the outer peripheral surface 92 of the fourth part 89, and the second part 83 and the fourth part 89 are fitted together. A tightening allowance is provided. In a state where the fourth part 89 is press-fitted into the second part 83 and the second part 83 is overlapped with the fourth part 89 in the radial direction, the first contact part 86 of the second part 83 is the second valve seat 87. The second contact portion 91 is contacted from the axial direction. In this state, the support portion 90 comes into contact with the radially inner upper surface of the second valve body 39, and the radially outer portion of the lower surface of the second valve body 39 makes line contact with the first seat surface 84. The second valve body 39 is pushed and elastically deformed by the support portion 90 and the first seat surface 84, and applies a restoring force directed downward in the axial direction to the first seat surface 84.

  When assembling the shock absorber 80, first, the second valve body 39 is placed on the first seat surface 84 of the first valve seat 81, the fourth portion 89 is press-fitted into the second portion 83, and the second contact portion 91 is inserted. The first contact portion 86 is contacted. Thereby, the assembly 96 in which the first valve seat 81 and the second valve seat 87 sandwich the second valve body 39 is obtained. According to the assembly 96, the amount of pre-deflection of the second valve body 39 when the first contact portion 86 of the first valve seat 81 contacts the second contact portion 91 of the second valve seat 87 is set. Can be constant. Further, the assembly 96 allows visual confirmation from the first part 82 side of the first valve seat 81 whether or not the second valve body 39 is attached at a proper position. Furthermore, since three parts can be made into one part by the assembly 96, the operation | work which accommodates each part in the inner tube 12 can be simplified.

  Next, after the regulating member 46 is accommodated at the position of the step portion 94 from the lower end of the inner tube 12, the third valve body 48, the assembly 96, the first valve body 35, and the regulating member 31 are accommodated in the inner tube 12 in order. To do. Next, a bent portion 95 is formed by bending the lower end of the inner tube 12, and the regulating member 46, the assembly 96 and the regulating member 31 are caulked and fixed to the inner tube 12.

  Even if the size of the bent portion 95 (the axial distance between the stepped portion 94 and the bent portion 95) varies and an axial gap is generated between the restricting member 46, the assembly 96, and the restricting member 31, the assembled portion Since the fourth portion 89 is press-fitted into the second portion 83 of the solid 96, the magnitude of the pre-deflection of the second valve body 39 can be kept unchanged. Therefore, even if the size of the bent portion 95 varies, the pressure in the lower oil chamber 25 that opens the second flow path 37 (see FIG. 2) by the second valve element 39 can be prevented from varying.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a cross-sectional view of the shock absorber 100 according to the fifth embodiment, and FIG. 11 is an exploded view of a portion of the shock absorber 100 that constitutes the oil lock device. In FIG. 10, illustration of the outer tube 11 and the hollow rod 16 and a part of the inner tube 12 are omitted for easy understanding. In addition, about the part same as 1st Embodiment and 4th Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted.

  As shown in FIG. 10, in the shock absorber 100, the first valve seat 101, the second valve seat 87, and the regulating member 46 are arranged on the inner periphery of the lower end portion of the inner tube 12 in order from the bottom in the axial direction. Yes. The second valve body 39 is disposed between the first valve seat 101 and the second valve seat 87, and the first valve body 103 is disposed between the restriction portion 102 of the first valve seat 101 and the second valve body 39. Has been. The first valve seat 101, the second valve seat 87, and the regulating member 46 have a stepped portion 94 formed on the inner periphery of the inner tube 12 and the tip (lower end) of the inner tube 12 bent inward in the radial direction. It is fixed between the bent part 95 and the position in the axial direction is restricted.

  As shown in FIG. 11, the first valve seat 101 is provided with a regulating portion 102 that projects in an annular shape from the lower end portion in the axial direction of the first portion 82 toward the inside in the radial direction. The restriction part 102 is a part for restricting the movement of the first valve body 103 in the axial direction. Since the restriction portion 102 is provided in the first valve seat 101, the restriction member 31 (see FIG. 9) can be omitted, and the number of parts can be reduced accordingly.

  The first valve body 103 is an annular member that can be seated on the second valve seat 87 (the lower surface of the second valve body 39). The first valve body 103 moves in the axial direction between the restriction portion 102 of the first valve seat 101 and the second valve body 39. As for the 1st valve body 103, the protrusion part 104 protrudes from the multiple places of a lower end surface. Since the protrusions 104 are arranged at intervals in the circumferential direction, the flow path between the restriction portion 102 and the first valve body 103 is ensured even when the protrusion 104 contacts the restriction portion 102.

  When assembling the shock absorber 100, first, the first valve body 103 is placed on the restriction portion 102 of the first valve seat 101, and the second valve body 39 is placed on the first seat surface 84. Next, the fourth part 89 is press-fitted into the second part 83 and the first contact part 86 is brought into contact with the second contact part 91. Thereby, the assembly 105 in which the first valve seat 101 and the second valve seat 87 sandwich the second valve body 39 is obtained. According to the assembly 105, the amount of pre-deflection of the second valve body 39 when the first contact portion 86 contacts the second contact portion 91 of the second valve seat 87 can be made constant. Further, since the four parts can be made into one part by the assembly 105, the operation of housing each part in the inner tube 12 can be simplified.

  Next, after the regulating member 46 is accommodated at the position of the step portion 94 from the lower end of the inner tube 12, the third valve body 48 and the assembly 105 are accommodated in the inner tube 12 in order. Next, a bent portion 95 is formed by bending the lower end of the inner tube 12, and the regulating member 46 and the assembly 105 are caulked and fixed to the inner tube 12.

  According to the fifth embodiment, in addition to the operational effects obtained in the fourth embodiment, the restriction portion 102 formed in the first valve seat 101 reduces the number of parts and the assembly process of housing each part in the inner tube 12. Simplification can be realized.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed. For example, the position and number of the oil holes 19 can be set as appropriate.

  In each of the above-described embodiments, the shock absorbers 10, 60, 70, 80, 100 have the third valve body 48 in which the inner flow path 49 between the hollow rod 16 and the expansion side throttle path is the expansion side throttle path, Although the case where the damping force generating mechanism such as the oil hole 20 is provided has been described, it is not necessarily limited thereto. In a front fork in which a first shock absorber and a second shock absorber are disposed on both sides of a wheel, the first shock absorber has a built-in damping force generation mechanism, the second shock absorber has a built-in spring, but the damping force generation mechanism is When not built in, it is naturally possible to arrange the oil lock devices 30, 61, 71 described in the respective embodiments in the second shock absorber. This is because the oil can be locked using the lubricating oil inside the second shock absorber.

  In each of the above embodiments, the case where the damping force generating mechanism includes the third valve body 48 that moves in the axial direction has been described, but the present invention is not necessarily limited thereto. It is naturally possible to provide another known damping valve in place of the third valve body 48.

  In the first to fourth embodiments, the case where the regulating member 31 that regulates the axial movement of the first valve body 35 is provided separately from the first valve seats 33 and 81 has been described. It is not something that can be done. As in the fifth embodiment, it is naturally possible to integrate the regulating member 31 with the first valve seat 33. Even when the restricting member 31 is integrated with the first valve seats 33 and 81, the restricting member 31 and the third valve body 48 are assembled in this order on the inner periphery of the inner tube 12 so that the restricting member 31 is integrated. After the seat 33 is assembled last, the tip of the inner tube 12 can be bent and fixed by caulking.

  In each of the above embodiments, the case where the second valve body 39 is formed by one annular thin plate has been described, but the present invention is not necessarily limited thereto. It is naturally possible to form the second valve body 39 by arranging a plurality of thin plates. In this case, the set pressure at which the second valve body 39 is deformed can be adjusted by increasing or decreasing the number of thin plates.

  Although the said 1st Embodiment demonstrated the case where the chamfering part 38 was provided over the perimeter in the corner near the control member 31 among the outer periphery of the 1st valve body 35, it is not necessarily restricted to this. . Of course, it is possible to provide a chamfered portion over the entire circumference of the outer periphery of the first valve body 35 at the corner closer to the second valve body 39. By providing the chamfered portion at the corner on the side close to the second valve body 39, the hydraulic oil can easily flow into the second flow path 37 from the second gap 51. Further, it is naturally possible to provide chamfered portions at both corners of the outer periphery of the second valve body 39 (a corner close to the restriction member 31 and a corner close to the second valve body 39).

  In the fourth and fifth embodiments, the fit between the first valve seat 81 and 101 and the second valve seat 87 is an interference fit (the second valve seat 87 is press-fitted into the first valve seat 81 and 101). However, the present invention is not necessarily limited to this. Naturally, the fitting of the first valve seat 81, 101 and the second valve seat 87 can be a clearance fit or an intermediate fit. Also in these cases, the first valve seats 81 and 101 and the second valve seat 87 are caused by friction between the second portion 83 of the first valve seat 81 and the fourth portion 89 of the second valve seat 87 that overlap in the radial direction. The temporarily fixed assemblies 96 and 105 are obtained. As a result, the operation of housing each component in the inner tube 12 can be simplified.

  In the fourth and fifth embodiments, the case where the fourth portion 89 of the second valve seat 87 is inserted into the second portion 83 provided in the first valve seat 81 has been described. It is not something that can be done. For example, a concave portion such as a groove or a recess is formed in the fourth portion 89 of the second valve seat 87, and a convex portion to be inserted into the concave portion is provided in the second portion 83 of the first valve seat 81, or the first valve It is naturally possible to form a recess such as a groove or a recess in the second portion 83 of the seat 81 and provide a projection to be inserted into the recess in the fourth portion 89 of the second valve seat 87. In those cases, the tip of the convex portion and the bottom of the concave portion can abut against each other in the axial direction, and the tip of the convex portion and the bottom of the concave portion are in contact with the first contact portion 86 and the second contact portion 91. Applicable.

  Each of the above embodiments may be modified by adding or exchanging a part of the configuration of the other embodiment to the embodiment. For example, the second valve seat 73 in which the displacement restricting portion 75 and the groove 76 described in the third embodiment are formed, together with the first valve seat 72, the second valve seat 41 and the first valve of the second embodiment. It is of course possible to replace the seat 33. Moreover, it is naturally possible to provide the displacement restricting portion 75 and the groove portion 76 described in the third embodiment in the second valve seat 87 of the fourth embodiment and the fifth embodiment. Further, the protrusion 104 of the first valve body 103 described in the fifth embodiment is provided on the first valve body 35 of the first to fourth embodiments, and the regulation of the first to fourth embodiments. Of course, the stopper 32 of the member 31 can be omitted.

10, 60, 70, 80, 100 Shock absorber 11 Outer tube 12 Inner tube 16 Hollow rod
25 Lower oil chamber 33, 72, 81, 101 First valve seat 34, 84 First seat surface (seat surface)
35, 62, 103 First valve body 36 First flow path
37 Second channel 39 Second valve body
40 1st gap (gap)
41, 73, 87 Second valve seat 42, 74, 90 Support portion 45, 93 Third seat surface (upper seat surface)
48 Third valve body 65 Spring 75 Displacement restricting portion 76 Groove portion 82 First portion 83 Second portion 86 First contact portion 88 Third portion 89 Fourth portion 91 Second contact portion

Claims (7)

An inner tube arranged on the vehicle body side;
An outer tube disposed on the wheel side and in sliding contact with the outer periphery of the inner tube;
A hollow rod provided at the bottom of the outer tube;
A first valve seat and a second valve seat arranged in order from the wheel side to the vehicle body side in the axial direction of the inner tube on the inner periphery of the inner tube;
A first valve body and a second valve body, which are arranged so as to be seated on the second valve seat and the first valve seat, respectively, and which are sequentially arranged in the axial direction from the wheel side to the vehicle body side. ,
A lower oil chamber surrounded by the outer tube, the inner tube and the hollow rod is formed on the wheel side of the first valve body and the second valve body,
The first valve body can be seated on the second valve seat in a state in which a first flow path is provided between an outer periphery of the hollow rod and an inner periphery of the first valve body ,
The second valve body is disposed in a state where a gap is provided between an outer periphery of the hollow rod and an inner periphery of the second valve body, the gap is connected in series with the first flow path, and the gap Is larger than the cross-sectional area of the first flow path,
In the pressure side stroke in which the inner tube enters the lower oil chamber, the first valve body is seated on the second valve seat, and the second valve body is urged downward in the axial direction. In close contact with the seat surface of the first valve seat, close the second flow path provided in parallel with the first flow path,
When the lower oil chamber becomes higher than a predetermined pressure, the second valve body opens to open the second flow path in a state where the first valve body is seated on the second valve seat,
When reversed to the extension stroke, the first valve body is separated from the second valve seat, and the hydraulic oil flows into the lower oil chamber through the gap . An inner tube arranged on the vehicle body side;
An outer tube disposed on the wheel side and in sliding contact with the outer periphery of the inner tube;
A hollow rod provided at the bottom of the outer tube;
A first valve seat and a second valve seat arranged in order from the wheel side to the vehicle body side in the axial direction of the inner tube on the inner periphery of the inner tube;
A first valve body and a second valve body, which are arranged so as to be seated on the second valve seat and the first valve seat, respectively, and which are sequentially arranged in the axial direction from the wheel side to the vehicle body side. ,
A lower oil chamber surrounded by the outer tube, the inner tube and the hollow rod is formed on the wheel side of the first valve body and the second valve body,
The first valve body can be seated on the second valve seat in a state of providing a clearance from the outer periphery of the hollow rod,
Said second valve body, Ri adherable der the seating surface of the first valve seat in a state of being biased toward the lower side of the axial direction,
In the pressure side stroke in which the inner tube enters the lower oil chamber, when the lower oil chamber becomes higher than a predetermined pressure, the second valve body is in a state where the first valve body is seated on the second valve seat. Open,
The second valve seat includes a displacement restricting portion that restricts the maximum displacement of the second valve body,
The said displacement control part is a buffer provided in the end surface of the said axial direction lower side of the said 2nd valve seat . An inner tube arranged on the vehicle body side;
An outer tube disposed on the wheel side and in sliding contact with the outer periphery of the inner tube;
A hollow rod provided at the bottom of the outer tube;
A first valve seat and a second valve seat arranged in order from the wheel side to the vehicle body side in the axial direction of the inner tube on the inner periphery of the inner tube;
A first valve body and a second valve body, which are arranged so as to be seated on the second valve seat and the first valve seat, respectively, and which are sequentially arranged in the axial direction from the wheel side to the vehicle body side. ,
A lower oil chamber surrounded by the outer tube, the inner tube and the hollow rod is formed on the wheel side of the first valve body and the second valve body,
The first valve body can be seated on the second valve seat in a state of providing a clearance from the outer periphery of the hollow rod,
Said second valve body, Ri adherable der the seating surface of the first valve seat in a state of being biased toward the lower side of the axial direction,
In the pressure side stroke in which the inner tube enters the lower oil chamber, when the lower oil chamber becomes higher than a predetermined pressure, the second valve body is in a state where the first valve body is seated on the second valve seat. Open,
The first valve seat includes a first part formed in an annular shape, a second part protruding in the axial direction from the first part, and a first contact formed in the first part or the second part. And comprising
The second valve seat includes a third part formed in an annular shape, a fourth part protruding in the axial direction from the third part and overlapping the second part in the radial direction, and the third part or the first part. A first abutting portion and a second abutting portion that abuts in the axial direction while being formed in four parts,
A shock absorber in which the second valve body is biased downward in the axial direction in a state where the second contact portion is in contact with the first contact portion . The second valve seat includes an upper seat surface on the upper side in the axial direction from the lower surface thereof,
The first valve body according to claim 1, further comprising a third valve body that is disposed on an inner periphery of the inner tube on the upper side in the axial direction than the upper seat surface and that can be in close contact with the upper seat surface . The shock absorber in any one . The lower surface on the radially outer side of the second valve body is an annular member through which the hollow rod penetrates the center, and can be in close contact with the first valve seat in the closed state,
The second valve seat includes a support portion protruding downward in the axial direction,
The shock absorber according to any one of claims 1 to 4 , wherein the support portion presses a radially inner upper surface of the second valve body. Said second valve seat, the shock absorber according to claim 2, wherein a groove is formed on the end surface of the lower side of the said axis. The shock absorber according to any one of claims 1 to 6 , further comprising a spring that biases the first valve body upward in the axial direction.

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