JP2018162880A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper that can prevent a leaf valve laminated on a piston from being damaged during such as storage before shipment even if it is a damper that does not include a valve stopper.SOLUTION: In a damper, a stopper part for regulating a rod guide 4 for blocking an opening end of a cylinder 1 not to come close to a piston 3 is installed at least one of the cylinder 1, the piston 3 and the rod guide 4. The stopper part is disposed on an outside relative to an outer peripheral end of a leaf valve 5 stacked on a side of a stretch-side chamber of the piston 3 and a clearance is provided between the leaf valve 5 and the rod guide 4 at the closest approach between the piston 3 and the rod guide 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shock absorber.

  In general, the shock absorber is connected to a cylinder, a rod inserted in the cylinder so as to be movable in the axial direction, and connected to the tip of the rod and divides the inside of the cylinder into an extension side chamber and a pressure side chamber. A piston, a passage communicating the extension side chamber and the pressure side chamber provided in the piston, a leaf valve stacked on the piston and deflected when a liquid passes through the passage to provide resistance to the flow of the liquid, and the leaf valve And a valve stopper that regulates the amount of bending (see, for example, Patent Document 1).

  Such a shock absorber is used, for example, by being incorporated in a suspension of a vehicle, and when expanding and contracting, a resistance is applied by a valve to a flow of liquid flowing between the two chambers through a passage to reduce a differential pressure between the two chambers. It produces a damping force and suppresses the shaking of the vehicle body.

  In general, such a shock absorber is provided with extension regulating means for restricting the collision between the piston and the rod guide so that the piston and the rod guide do not collide even when the shock absorber is fully extended.

  However, for example, when the suspension spring is a leaf spring formed by stacking a plurality of leaf springs having different lengths, the leaf spring has a very high spring constant and a force acts in the compression direction. However, since it does not contract like a coil spring, the extension of the shock absorber is restricted and the piston and the rod guide do not collide.

  In this way, in the case where the extension limit regulating means for regulating the collision between the piston and the rod guide is provided in a portion other than the shock absorber of the suspension, it is not necessary to provide the stretch limit regulating means in the shock absorber itself. In some cases, the stretch restriction means may be omitted.

JP2015-117713A

  In the case of a shock absorber applied to a suspension whose extension is restricted in this way, the extension restriction means can be omitted, but if it is not necessary to restrict the amount of bending of the valve, the valve stopper can be eliminated. Cost can be reduced.

  However, in a single rod type shock absorber, if the compressive load is not applied, the shock absorber expands due to the internal pressure.

  At this time, if the shock absorber is equipped with a valve stopper, the valve stopper is placed between the leaf valve and the rod guide. It was in contact.

  However, if the valve stopper is omitted, the leaf valve stacked on the side of the extension side chamber of the piston may come into contact with the rod guide during storage and the surface of the leaf valve may be damaged, so the valve stopper cannot be omitted.

  Therefore, an object of the present invention is to provide a shock absorber that can prevent the leaf valve laminated on the piston from being damaged even when the shock absorber is not provided with a valve stopper during storage before shipment.

  Means for solving the above-mentioned problem is that at least one of the cylinder, the piston, and the rod guide is provided with a stopper portion that restricts the approach of the rod guide that closes the opening end of the piston and the cylinder, and the stopper portion Is disposed outside the outer peripheral end of the leaf valve superimposed on the extension side chamber side of the piston, and a gap is provided between the leaf valve and the rod guide when the piston and the rod guide are closest to each other. To do.

  Further, a step portion may be provided on the outer periphery of the rod, and the step portion may support the inner peripheral side of the leaf valve. According to this configuration, since the fulcrum of the leaf valve can be determined by the step provided on the outer periphery of the rod, instead of the spacer which has conventionally determined the fulcrum of the leaf valve, the spacer is omitted. The number of parts can be reduced.

  The stopper may be a protrusion provided on the rod guide side of the piston. According to this configuration, even when the shock absorber is stored before shipping, even if the rod moves in the retracting direction due to the pressure of the gas sealed in the cylinder, the protrusion provided on the rod guide side of the piston is The leaf valve is not in contact with the rod guide, and the leaf valve can be protected.

  The stopper may be a protrusion provided on the piston side of the rod guide. According to this configuration, even when the shock absorber is stored before shipping, even if the rod moves in the retracting direction due to the pressure of the gas sealed in the cylinder, the protrusion provided on the piston side of the rod guide Since the abutment restricts further movement of the rod, the leaf valve does not abut against the rod guide, and the leaf valve can be protected.

  Further, the stopper portion may be provided so as to protrude from the inner periphery of the cylinder. According to this configuration, even when the shock absorber is stored before shipping, even if the rod moves in the retracting direction due to the pressure of the gas sealed in the cylinder, the piston contacts the stopper that protrudes from the inner periphery of the cylinder. Since the further movement of the rod is restricted by contact, the leaf valve does not come into contact with the rod guide, and the leaf valve can be protected.

  According to the shock absorber of the present invention, the stopper portion that restricts the approach of the piston and the rod guide is provided in at least one of the cylinder, the piston, and the rod guide. Even if it moves in the withdrawal direction, the movement of the rod is restricted by the stopper portion. Therefore, even if the valve stopper is omitted, the leaf valve stacked on the piston can be prevented from coming into contact with the rod guide and being damaged.

It is a longitudinal cross-sectional view of the shock absorber according to the first embodiment, the left half is a vertical cross-sectional view of the shock absorber showing a fully extended state of the shock absorber, and the right half is a piston from the fully extended state of the shock absorber It is a longitudinal cross-sectional view of the buffer which shows the state arrange | positioned at the neutral position side. It is a partially expanded longitudinal cross-sectional view of the modification of the shock absorber of FIG. It is a longitudinal cross-sectional view of the shock absorber according to the second embodiment, the left half is a vertical cross-sectional view of the shock absorber showing a fully extended state of the shock absorber, and the right half is a piston from the fully extended state of the shock absorber It is a longitudinal cross-sectional view of the buffer which shows the state arrange | positioned at the neutral position side. It is a longitudinal cross-sectional view of the shock absorber according to the third embodiment, the left half is a vertical cross-sectional view of the shock absorber showing a fully extended state of the shock absorber, and the right half is a piston from the fully extended state of the shock absorber It is a longitudinal cross-sectional view of the buffer which shows the state arrange | positioned at the neutral position side.

  The present embodiment will be described below with reference to the drawings. The same reference numerals used throughout the several drawings indicate the same parts.

<First embodiment>
As shown in FIG. 1, the shock absorber D <b> 1 according to the present embodiment includes a cylinder 1, a rod 2 that is movably inserted into the cylinder 1, and an extension side chamber R <b> 1 provided in one end of the rod 2. A piston 3 that is partitioned into a pressure side chamber R2, a rod guide 4 that closes the opening of the cylinder 1 and guides the movement of the rod 2, and a leaf valve 5 that is superimposed on the extension side chamber R1 side of the piston 3. A protrusion 6 serving as a stopper for restricting the approach of the piston 3 and the rod guide 4 is provided outside the outer peripheral end of the third leaf valve 5.

  The configuration of the shock absorber D1 will be described in detail. As shown in FIG. 1, the shock absorber D1 is provided in a cylinder 1 filled with a working fluid such as hydraulic oil, and an upper end opening of the cylinder 1 so that the inside of the cylinder 1 is filled. An annular rod guide 4 that closes and a rod 2 that is inserted through the rod guide 4 so as to be movable in the axial direction are provided. Further, a piston 3 slidably contacting the inner peripheral surface of the cylinder 1 is connected to the tip of the rod 2, and the cylinder 1 is divided into two chambers, an extension side chamber R1 and a pressure side chamber R2. The shock absorber D <b> 1 includes a bottomed cylindrical outer cylinder 7 that covers the cylinder 1, and a reservoir chamber R <b> 3 is formed between the outer cylinder 7 and the cylinder 1. The reservoir chamber R3 is filled with hydraulic oil and gas, and the gas is sealed at a pressure of at least atmospheric pressure.

  Further, the piston 3 is provided with an extension side passage 10 and a pressure side passage 11 communicating with the extension side chamber R1 and the pressure side chamber R2. The extension side passage 10 is provided on the inner peripheral side of the piston 3, and the pressure side passage 11 is provided on the piston 3 side. It is arrange | positioned at the outer peripheral side, respectively.

  As shown in FIG. 1, an annular leaf valve 5 is overlapped on the upper surface of the piston 3 on the extension side chamber R <b> 1 side, and the pressure side passage 11 is closed by the leaf valve 5. Further, the leaf valve 5 is provided with a hole 5a at a position facing the extension side passage 10 so that the extension side passage 10 is not blocked. Thereby, in this example, the leaf valve 5 functions as a check valve that allows only the passage of hydraulic oil from the compression side chamber R2 toward the extension side chamber R1.

  On the other hand, a damping valve 8 composed of a plurality of annular leaf valves is laminated on the lower surface of the piston 3 on the pressure side chamber R2 side, and this damping valve 8 passes hydraulic oil from the extension side chamber R1 toward the pressure side chamber R2. Only this is allowed and resistance is given to the flow of this hydraulic oil.

  Next, the structure for connecting the piston 3 to the tip of the rod 2 will be described in detail. As shown in FIG. 1, the rod 2 according to the present embodiment includes a large diameter portion 2a, a small diameter portion 2b continuous to the large diameter portion 2a, and a step formed between the large diameter portion 2a and the small diameter portion 2b. A part 2c and a thread groove part 2d formed on the side opposite to the large diameter part of the small diameter part 2b are provided.

  As shown in FIG. 1, an annular leaf valve 5, a piston 3, a damping valve 8, and a spacer 9 are assembled in order from the top in FIG. 1 on the outer periphery of the small diameter portion 2 b of the rod 2. Then, when these members are assembled in this manner, when the valve nut 12 is screwed into the thread groove portion 2 d, these members are fixed to the small diameter portion 2 b of the rod 2.

  At this time, the inner peripheral side of the leaf valve 5 is supported by the step portion 2c, and when pressure is applied from the pressure side chamber R2, the pressure side passage 11 is opened by bending with the outer diameter portion of the step portion 2c as a fulcrum.

  Further, the end portion on the small diameter portion 2b side (the lower end in FIG. 1) of the large diameter portion 2a has a tapered shape that gradually decreases in diameter toward the small diameter portion 2b side. Thereby, the outer diameter of the step part 2c can be made smaller than the outer diameter of the large diameter part 2a. Therefore, if the inclination angle of the taper is adjusted, the outer diameter of the step portion 2c that supports the inner peripheral side of the leaf valve 5 can be adjusted, so that the fulcrum when the leaf valve 5 is bent can be set at an arbitrary position.

  When it is desired to make the support diameter, which is a fulcrum of bending in the leaf valve 5, smaller than the outer diameter of the stepped portion 2c, the second small diameter portion having a smaller diameter than the small diameter portion 2b is formed in the small diameter portion 2b as shown in FIG. 2e, a second step portion 2f having an outer diameter smaller than that of the step portion 2c is formed between the small diameter portion 2b and the second small diameter portion 2e, and the inner peripheral side of the leaf valve 5 is formed by the second step portion 2f. You may make it support.

  Although not shown, a valve disc that partitions the pressure side chamber R2 and the reservoir chamber R3 is fitted to the lower end of the cylinder 1. The valve disc includes a base valve (not shown) that allows only the hydraulic oil to pass from the pressure side chamber R2 to the reservoir chamber R3 and provides resistance to the flow of the hydraulic oil, and an operation toward the pressure side chamber R2 from the reservoir chamber R3. And a check valve (not shown) that allows only passage of oil.

  Further, as shown in FIG. 1, the rod guide 4 according to the present embodiment has a shaft portion 4a fitted into the upper end opening of the cylinder 1 and a diameter larger than that of the shaft portion 4a connected to the shaft portion 4a. The outer periphery of the outer cylinder 7 is provided with a flange portion 4b.

  A seal member 20 is placed above the rod guide 4 in FIG. The seal member 20 seals between the rod 2 and the outer cylinder 7 to seal the inside of the cylinder.

  Next, the operation of the shock absorber D1 will be described. When the shock absorber D1 is extended, the hydraulic oil moves from the expansion side chamber R1 in which the volume decreases to the pressure side chamber R2 in which the volume increases through the damping valve 8. Thereby, since the damping valve 8 gives resistance to the flow of the hydraulic oil passing through the expansion side passage 10, the shock absorber D1 exhibits the expansion side damping force. At this time, the volume of hydraulic oil with which the rod 2 retreats from the cylinder 1 is compensated from the reservoir chamber R3 via a check valve provided in the valve disk.

  On the other hand, when the shock absorber D1 contracts, the hydraulic oil moves from the pressure side chamber R2 whose volume decreases through the pressure side passage 11 to the expansion side chamber R1 whose volume increases, and the rod 2 enters the cylinder 1 and enters the rod. The hydraulic oil that has become excessive in volume is discharged from the pressure side chamber R2 to the reservoir chamber R3 via the base valve. As a result, the base valve provides resistance to the flow of hydraulic oil discharged from the pressure side chamber R2 to the reservoir chamber R3, so that the shock absorber D1 exhibits a pressure side damping force. In this example, the leaf valve 5 hardly gives resistance to the flow of hydraulic fluid that moves through the pressure side passage 11 from the pressure side chamber R2 whose volume decreases to the expansion side chamber R1 whose volume increases. ing. However, the leaf valve 5 may be caused to function as a damping valve that provides resistance to the flow of liquid moving from the compression side chamber R2 to the extension side chamber R1, for example, by increasing the number of leaf valves 5.

  Next, the protrusion 6 serving as a stopper portion that restricts the approach between the piston 3 and the rod guide 4 will be described in detail. The protrusion 6 of this example is annular, and is provided on the outer peripheral side end of the piston 3 on the extension side chamber R1 side, and is provided on the outer peripheral side from the outer peripheral end of the leaf valve 5 when viewed from the axial direction. Further, in this example, the outer peripheral surface of the protrusion 6 is flush with the outer peripheral surface of the piston 3, and when the shock absorber D <b> 1 expands and contracts, the outer peripheral surface of the protrusion 6 together with the outer peripheral surface of the piston 3 is It comes in sliding contact with the inner circumference.

  Thus, since the protrusion 6 is provided on the outer peripheral side from the outer peripheral end of the leaf valve 5 when viewed in the axial direction, it does not interfere with the leaf valve 5 and does not hinder the opening and closing of the leaf valve 5.

  In this example, the protrusion 6 as the stopper portion is provided at the outer peripheral end of the piston 3, but the protrusion 6 is provided outside the outer peripheral end of the leaf valve 5 of the piston 3. Therefore, it may be provided between the outer peripheral end of the leaf valve 5 and the outer peripheral end of the piston 3.

  In this example, the axial length of the protrusion 6 is set to be longer than at least the thickness of the leaf valve 5, and the protrusion 6 protrudes further toward the rod guide 4 than the leaf valve 5. .

  However, the axial length of the protrusion 6 is not necessarily set longer than the thickness of the leaf valve 5, and the rod guide side end of the protrusion 6 is disposed closer to the rod guide side than the rod guide side end of the leaf valve 5. It only has to be done.

  Here, since the pressure of the gas sealed in the reservoir chamber R3 is higher than the atmospheric pressure, the buffer chamber D3 is sealed in the reservoir chamber R3 during storage before shipment, for example, before the shock absorber D1 is incorporated into the suspension. The gas is fully extended by the gas pressure.

  On the other hand, according to the configuration of this example, as shown on the left half side of FIG. 1, even if the rod 2 moves in the retracting direction and the piston 3 and the rod guide 4 approach each other, the leaf valve 5 remains in the rod guide. Before the contact with 4, the protrusion 6 contacts the rod guide 4, and further movement of the rod 2 is restricted.

  Therefore, even when the valve stopper that restricts the bending of the leaf valve 5 is omitted, a gap is formed between the leaf valve 5 and the rod guide 4 so that the rod guide 4 contacts the surface of the leaf valve 5. Without being damaged, the surface of the leaf valve 5 is prevented from being damaged.

  In this example, since the protrusion 6 is formed integrally with the piston 3, the number of parts of the shock absorber D1 does not increase even if a stopper portion is provided. Therefore, according to the shock absorber D1 of this example, the valve stopper can be omitted without increasing the number of parts, and therefore the number of parts can be reduced.

  Further, in a normal shock absorber, a valve stopper that restricts the bending of the leaf valve 5 is provided between the leaf valve 5 and the stepped portion 2 c, so the bending of the leaf valve 5 is between the valve stopper and the leaf valve 5. There is a spacer to determine the fulcrum.

  On the other hand, in the shock absorber D1 of this example, the inner peripheral side of the leaf valve 5 is supported by the step 2c provided on the outer periphery of the rod 2, and the fulcrum of the leaf valve 5 is bent by the outer diameter of the step 2c. Therefore, the spacer can be omitted, and the number of parts can be further reduced.

  However, a spacer may be provided between the step portion 2c and the leaf valve 5, and the fulcrum of the leaf valve 5 may be determined by the outer diameter of the spacer. When the spacer is provided, the accuracy of the outer diameter of the step portion 2c is not required, so that the rod 2 can be easily processed.

  Further, in this example, the protrusion 6 is formed in an annular shape, but may be formed in, for example, a C ring shape or a U shape, and a plurality of or one rod-shaped protrusion may be provided along the circumferential direction of the piston 3. You may make it provide. With such a shape, the material used can be reduced as compared with the case where the protrusion 6 is formed in an annular shape.

  In the present embodiment, the shock absorber D1 is a double-tube shock absorber. However, the shock absorber D1 is a single-tube shock absorber provided with a reservoir composed of an air chamber partitioned by a free piston in the cylinder 1. Also good.

  In addition, since the gas sealed in the air chamber of the single-cylinder shock absorber is sealed at a higher pressure than the gas sealed in the reservoir chamber R3 of the double-cylinder shock absorber, it can be used during storage. Strong force to push the rod 2 in the exit direction. Therefore, when the shock absorber D1 is a single-tube shock absorber, the shock absorber D1 of this example exhibits the effect of protecting the leaf valve 5 more remarkably.

<Second Embodiment>
Next, the shock absorber D2 according to the second embodiment will be described. As shown in FIG. 3, the shock absorber D <b> 2 is the first embodiment in that the stopper portion that restricts the approach between the piston 3 and the rod guide 4 is a protrusion 30 provided on the piston side of the rod guide 4. It differs from the buffer D1 which concerns.

  Here, it demonstrates centering around a different point from the buffer D1 which concerns on 1st embodiment mentioned above, attaches | subjects the same code | symbol to the structure which has the same function, and abbreviate | omits description.

  As shown in FIG. 3, the protrusion 30 according to the present embodiment is annular, and is a lower end outer peripheral end portion of the shaft portion 4 a of the rod guide 4, and from an outer peripheral end of the leaf valve 5 when viewed from the axial direction. It is provided on the outer peripheral side.

  Further, in this example, the axial length of the protrusion 30 is the imaginary line X extending horizontally from the contact surface 3 a of the piston 3 facing the protrusion 30 and the imaginary line extending horizontally from the end surface on the rod guide side of the leaf valve 5. It is at least longer than the axial length between the line Y. Therefore, the rod 2 moves in the retracting direction due to the pressure of the gas sealed in the reservoir chamber R3 when the shock absorber D2 is stored in the suspension before shipment, and the piston 3 and the rod guide 4 approach each other. However, as shown on the left half side of FIG. 3, before the leaf valve 5 and the rod guide 4 come into contact with each other, the protrusion 30 is the surface outside the portion of the piston 3 where the leaf valve 5 is seated. Further movement of the rod 2 is restricted by contacting the contact surface 3a.

  Therefore, even when the valve stopper that restricts the bending of the leaf valve 5 is omitted, a gap is formed between the leaf valve 5 and the rod guide 4 so that the rod guide 4 contacts the surface of the leaf valve 5. Without being damaged, the surface of the leaf valve 5 is prevented from being damaged.

  Moreover, in this example, since the protrusion 30 is formed integrally with the rod guide 4, even if a stopper portion is provided, the number of parts of the shock absorber D2 does not increase. Therefore, according to the shock absorber D2 of this example, the valve stopper can be omitted without increasing the number of parts, and therefore the number of parts can be reduced.

  Also in the shock absorber D2 of this example, since the fulcrum of the leaf valve 5 is determined by the outer diameter of the step portion 2c provided on the outer periphery of the rod 2, it is provided between the valve stopper and the leaf valve 5. Therefore, the number of parts can be further reduced.

  However, in this example, the fulcrum of bending of the leaf valve 5 is determined by the step portion 2c, but a spacer is provided between the step portion 2c and the leaf valve 5, and the leaf valve 5 has the outer diameter of the spacer. The fulcrum of bending may be determined. When the spacer is provided, the accuracy of the outer diameter of the step portion 2c is not required, so that the rod 2 can be easily processed.

  Further, in this example, the protrusion 30 is formed in an annular shape, but may be formed in, for example, a C ring shape or a U-shape, or a plurality of rod-shaped protrusions or a single one along the circumferential direction of the rod guide 4. One may be provided. With such a shape, the material used can be reduced as compared with the case where the protrusion 30 is formed in an annular shape.

  Further, similarly to the shock absorber D1 according to the first embodiment, the shock absorber D2 may be a single-tube shock absorber. When the shock absorber D2 is a single-tube shock absorber that pushes the rod 2 in the retracting direction during storage, etc., and is stronger than the double-tube shock absorber, the shock absorber D2 in this example protects the leaf valve 5. The effect to do is demonstrated more remarkably.

<Third embodiment>
Next, the shock absorber D3 according to the third embodiment will be described. As shown in FIG. 4, the shock absorber D <b> 3 is a first embodiment in that the stopper portion that restricts the approach of the piston 3 and the rod guide 4 is a convex portion 40 that protrudes from the inner periphery of the cylinder 1. This is different from the shock absorber D1 according to the embodiment.

  Here, it demonstrates centering around a different point from the buffer D1 which concerns on 1st embodiment mentioned above, attaches | subjects the same code | symbol to the structure which has the same function, and abbreviate | omits description.

  The convex portion 40 according to the present embodiment is formed by roll crimping from the upper outer periphery in FIG. 4 of the cylinder 1 and projecting annularly from the inner periphery of the cylinder 1.

  Further, the radial length of the convex portion 40 is set to be at least shorter than the width from the outer peripheral side end of the piston 3 to the outer peripheral side end of the leaf valve 5, and the convex portion 40 is viewed from the axial direction. It is provided on the outer peripheral side from the outer peripheral end of the leaf valve 5.

  According to this configuration, the rod 2 moves in the retracting direction due to the pressure of the gas sealed in the reservoir chamber R3 during storage before shipping, for example, before the shock absorber D3 is incorporated into the suspension, so that the piston 3 and the rod guide As shown in the left half of FIG. 3, before the leaf valve 5 and the rod guide 4 come into contact with each other, the convex portion 40 is the outer surface of the portion of the piston 3 where the leaf valve 5 is seated. Further contact of the rod 2 with the contact surface 3a is restricted.

  Therefore, even when the valve stopper that restricts the bending of the leaf valve 5 is omitted, a gap is formed between the leaf valve 5 and the rod guide 4 so that the rod guide 4 contacts the surface of the leaf valve 5. Without being damaged, the surface of the leaf valve 5 is prevented from being damaged.

  Moreover, in this example, since the convex part 40 is provided by roll caulking the cylinder 1 from the outer periphery, it is formed integrally with the cylinder 1. Therefore, even if the stopper portion is provided, the number of parts of the shock absorber D3 does not increase. Therefore, according to the shock absorber D3 of this example, the valve stopper can be omitted without increasing the number of parts, and therefore the number of parts can be reduced.

  Also in the shock absorber D3 of this example, since the fulcrum of the leaf valve 5 is determined by the outer diameter of the step portion 2c provided on the outer periphery of the rod 2, it is provided between the valve stopper and the leaf valve 5. Therefore, the number of parts can be further reduced.

  However, in this example, the fulcrum of bending of the leaf valve 5 is determined by the step portion 2c, but a spacer is provided between the step portion 2c and the leaf valve 5, and the leaf valve 5 has the outer diameter of the spacer. The fulcrum of bending may be determined. When the spacer is provided, the accuracy of the outer diameter of the step portion 2c is not required, so that the rod 2 can be easily processed.

  Furthermore, in this example, since the convex part 40 is provided by roll caulking, it is advantageous in that an existing cylinder can be used.

  Moreover, the convex part 40 of this example is provided in the upper part in FIG. 4 from the range which strokes with respect to the cylinder 1 of the piston 3 after incorporating the buffer D3 in the suspension. Therefore, after the shock absorber D3 is incorporated into the suspension, even if the shock absorber D3 is extended, the piston 3 does not contact the convex portion 40 and does not hinder the movement of the piston 3.

  Moreover, since the convex part 40 is provided by carrying out roll crimping after inserting the piston 3 in the cylinder 1, it does not become obstructive when assembling the buffer D3.

  In addition, although the convex part 40 of this example is formed so that it may protrude from the inner periphery of the cylinder 1 in an annular shape, the convex part 40 is not limited to an annular shape, and is formed so as to protrude from the inner periphery of the cylinder 1. Just do it.

  Although not shown, instead of the convex portion 40 formed on the cylinder 1 by roll caulking, an annular groove is provided on the inner periphery of the cylinder 1, and a stopper is formed by attaching a C pin to the annular groove. Also good.

  Even in this configuration, the C pin contacts the outside of the portion of the piston 3 where the leaf valve 5 is seated before the leaf valve 5 and the rod guide 4 abut, as in the case where the convex portion 40 is provided. A gap is formed between the leaf valve 5 and the rod guide 4 to prevent the surface of the leaf valve 5 from being damaged.

  Moreover, it is good also considering the buffer D3 as a single cylinder type shock absorber like the buffer D1 which concerns on 1st embodiment. When the shock absorber D3 is a single-tube shock absorber that pushes the rod 2 in the retracting direction during storage, etc., and is stronger than the double-tube shock absorber, the shock absorber D3 in this example protects the leaf valve 5. The effect to do is demonstrated more remarkably.

  Although the preferred embodiments of the present invention have been described in detail above, it is obvious that modifications, changes and modifications can be made without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1 ... Cylinder, 2 ... Rod, 2c ... Step part, 3 ... Piston, 4 ... Rod guide, 5 ... Leaf valve, 6,30 ... Projection, 40 ...・ Convex part, D1, D2, D3 ... Shock absorber, R1 ... Extension side chamber, R2 ... Pressure side chamber

Claims (5)

A cylinder,
A rod movably inserted into the cylinder;
A piston which is provided at one end of the rod and divides the inside of the cylinder into an extension side chamber and a compression side chamber;
A rod guide for closing the open end of the cylinder and guiding the movement of the rod;
A leaf valve superimposed on the extension side chamber side of the piston,
In a shock absorber that does not have a valve stopper that regulates the deflection of the leaf valve,
At least one of the cylinder, the piston, and the rod guide is provided with a stopper portion that regulates the approach of the piston and the rod guide,
The said stopper part is arrange | positioned outside the outer peripheral end of the said leaf valve, and provides the clearance gap between the said leaf valve and the said rod guide when the said piston and the said rod guide approach the closest. A step is provided on the outer periphery of the rod,
The shock absorber according to claim 1, wherein the step portion supports an inner peripheral side of the leaf valve. The shock absorber according to claim 1 or 2, wherein the stopper portion is a protrusion provided on a rod guide side of the piston. The shock absorber according to claim 1 or 2, wherein the stopper portion is a protrusion provided on a piston side of the rod guide. The shock absorber according to claim 1 or 2, wherein the stopper portion is provided so as to protrude from an inner periphery of the cylinder.

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