JP2008248955A - Damper and assembling tool of damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damper improved in riding comfort in a vehicle, and also to provide an assembling tool for assembling the damper. <P>SOLUTION: The damper includes a cylinder 1; a cap 2 for blocking an end of the cylinder 1; a pipe 3 having an enlarged diameter part 3a which is fitted in the cylinder 1 and a small diameter part 3b which is connected with the cap 2, wherein an inner part is communicated with an outer part and a reservoir R is formed between the pipe 3 and the cylinder 1; a rod 4 inserted in the cylinder 1 and having its end side inserted in the pipe 3; an annular guide member 5 for guiding an end of the rod 4 while fixed at an inner circumferential side of the enlarged diameter part 3a of the pipe 3; a piston 6 provided in a middle part of the rod 4 and separating the cylinder 1 into two pressure chambers R1, R2; and an orifice 3c, provided in the enlarged diameter part 3a of the pipe 3, for communicating a fluid chamber L and the pressure chamber R2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shock absorber and a shock absorber assembly tool.

  In a conventional shock absorber, for example, a cylinder, a rod inserted into the cylinder, a piston provided in the middle of the rod and defining two pressure chambers in the cylinder, and extended to the cylinder And a reservoir that is formed in a cylindrical extension and into which one end of the rod is inserted.

According to this double rod type shock absorber, the pressure chamber and the reservoir are communicated with each other through the gap between the rod and the bearing member that guides the rod, and the volume change due to the change in the hydraulic oil temperature is compensated by the reservoir. (For example, refer to Patent Document 1).
Japanese Patent Laying-Open No. 2004-270902 (FIG. 1)

  In such a shock absorber, as described above, the rod is inserted into the reservoir, and the pressure in the air chamber always acts on the rod, and this extends the shock absorber as a rod reaction force. In addition, since the rod changes the volume of the air chamber in the reservoir during expansion and contraction of the shock absorber, the rod reaction force changes.

  Therefore, when such a shock absorber is applied to a vehicle, the rod reaction force not only affects the vehicle height, but also affects the ride comfort in the vehicle, so the pressure in the air chamber is necessarily limited. It cannot be set freely.

  In other words, there is no degree of freedom in setting the pressure in the air chamber, in other words, there is no degree of freedom in setting the damping force generated by the shock absorber and the response. There is a possibility that the optimum setting for the ride comfort in the vehicle cannot be performed.

  Therefore, the present invention was devised to improve the above-described problems, and the object of the present invention is to provide a shock absorber that can improve riding comfort in a vehicle. It is to provide an assembly tool suitable for assembling a shock absorber.

  In order to achieve the above object, the shock absorber in the problem solving means of the present invention comprises a cylinder, a cap that closes one end of the cylinder, an enlarged diameter portion and a smaller diameter portion, and the enlarged diameter portion is fitted into the cylinder and the The pipe is connected to the cap, the inside communicates with the outside, and forms a reservoir consisting of a liquid chamber and an air chamber between the cylinder and the cylinder, and one end is inserted into the pipe. A rod that is fixed to the inner peripheral side of the enlarged diameter portion of the pipe and guides one end of the rod, and a piston that is provided in the middle of the rod and that separates the two pressure chambers in the cylinder And an orifice provided in the enlarged diameter portion of the pipe to communicate the liquid chamber and the pressure chamber.

  Furthermore, in order to achieve the above object, a shock absorber according to another means for solving problems of the present invention comprises a cylinder, a cap that closes one end of the cylinder, an enlarged diameter portion and a smaller diameter portion, and the enlarged diameter portion is in the cylinder. A pipe that is fitted and has a small-diameter portion connected to a cap and communicates the inside to the outside and forms a reservoir between the cylinder, and a rod that is inserted into the cylinder and has one end inserted into the pipe. An annular guide member that is fixed to the inner peripheral side of the enlarged diameter portion of the pipe and guides one end of the rod, a piston that is provided in the middle of the rod and that separates the two pressure chambers in the cylinder, and a small diameter of the pipe An annular free piston that is slidably inserted between the cylinder and the cylinder and divides the reservoir into a liquid chamber and an air chamber, and an orifice that is provided in the enlarged diameter portion of the pipe and communicates the liquid chamber and the pressure chamber Characterized by comprising a.

  The assembly tool for the shock absorber in the problem solving means of the present invention includes a cylinder, a cap for closing one end of the cylinder, an enlarged diameter portion and a smaller diameter portion, and the enlarged diameter portion is fitted in the cylinder and the smaller diameter portion. Is connected to the cap and forms a reservoir between the cylinder, a rod that is inserted into the cylinder and one end is inserted into the pipe, and a rod that is fixed to the inner peripheral side of the expanded portion of the pipe An annular guide member that guides one end of the cylinder, a piston that is provided in the middle of the rod and that separates two pressure chambers in the cylinder, and a reservoir that is slidably inserted between the small diameter portion of the pipe and the cylinder A step of injecting liquid into a liquid chamber of a shock absorber provided with an annular free piston that divides the liquid chamber and the air chamber, and an orifice that is provided in an enlarged diameter portion of the pipe and communicates with the liquid chamber and the pressure chamber. An assembly tool for a shock absorber that positions the free piston at a predetermined position in the cylinder, and a base that is fitted to one end of the cylinder, and an assembly that is coupled to the base and can be screwed into the air chamber side end of the free piston. And a rod.

  According to the shock absorber of the present invention, since no rod reaction force is generated, the pressure in the air chamber can be set freely without being restricted by the pressure setting in the air chamber, and the generated damping force of the shock absorber In addition, the degree of freedom in setting responsiveness can be dramatically increased, and the pressure in the air chamber can be set to be optimal for the ride comfort in the vehicle, so that the ride comfort in the vehicle can be greatly improved.

  Also, since a pipe connected to a cap that closes the end of the cylinder is inserted into the cylinder to form an annular reservoir in the cylinder, the configuration of the double rod type shock absorber is realized with a monotube. In addition, the outer diameter of the shock absorber can be made compact, the pressure receiving area of the piston can be set large, and the shock absorber can be suitable for generating a large damping force.

  Further, a pipe whose inside is opened to the atmosphere is inserted into the cylinder so as to form an annular reservoir in the cylinder, and this reservoir is communicated with the pressure chamber by an orifice provided in the enlarged diameter portion of the pipe. Therefore, it is possible to manufacture the shock absorber easily without complicating the structure of the shock absorber.

  Furthermore, it is possible to easily inject liquid into the liquid chamber of the shock absorber by using a shock absorber assembly tool, and the volume change of the liquid chamber is not caused when the shock absorber is assembled. The shock absorber can be manufactured as designed, and the performance of the shock absorber does not vary from product to product, and the product yield is improved.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a shock absorber according to an embodiment. FIG. 2 is a diagram illustrating a process of injecting a liquid into the liquid chamber of the buffer according to the embodiment.

  As shown in FIG. 1, the shock absorber D in one embodiment includes a cylinder 1, a cap 2 that closes one end of the cylinder 1, an enlarged diameter portion 3 a, and a reduced diameter portion 3 b, and the enlarged diameter portion 3 a is inside the cylinder 1. Is connected to the cap 2 so that the inside is communicated to the outside and the reservoir 3 is formed between the pipe 1 and the cylinder 1, and the one end 4a side is inserted into the cylinder 1 A rod 4 inserted into the pipe 3, an annular guide member 5 that is fixed to the inner peripheral side of the enlarged diameter portion 3 a of the pipe 3 and guides one end 4 a of the rod 4, and is provided in the middle of the rod 4 and a cylinder 1, a piston 6 separating two pressure chambers R1 and R2, and a small diameter portion 3b of a pipe 3 and a cylinder 1 are slidably inserted to partition a reservoir R into a liquid chamber L and a gas chamber G. An annular free piston 7 Provided enlarged diameter portion 3a of the pipe 3 has a liquid chamber L and the pressure chamber R2 is configured to include an orifice 3c communicating.

  Hereinafter, each member will be described in detail. The cylinder 1 is provided with a screw portion 1a on the outer periphery of the upper end in FIG. 1, and the screw portion 1a is provided with an annular suspension spring receiver S and a rotation stopper for the suspension spring receiver S. A nut N to be prevented is screwed and the suspension spring receiver S can be moved in the vertical direction with respect to the cylinder 1 by rotating, thereby adjusting the vehicle height.

  The cylinder 1 also has a screw portion 1b on the outer periphery of the lower end in FIG. 1, and a cap 2 that closes the lower end in FIG. 1, which is one end of the cylinder 1, is screwed to the screw portion 1b. The cap 2 includes a mounting bracket 2a for attaching the lower end of the cylinder 1 to the axle side of the vehicle.

  The cap 2 faces the inside of the cylinder 1 and opens from the upper end in FIG. 1, and opens from the side to communicate with the fitting hole 2b to the outside of the shock absorber D. A horizontal hole 2c is provided, and the lower end in FIG. 1 which is the tip of the small diameter portion 3b of the pipe 3 inserted into the cylinder 1 is fitted into the fitting hole 2b.

  The pipe 3 is enlarged in diameter at the upper end side in FIG. 1 to form an enlarged diameter portion 3a, and the lower portion from the enlarged diameter portion 3a is a small diameter portion 3b. The outer periphery of the lower end in FIG. An annular groove 3d is formed. Further, a longitudinal groove along the vertical direction in FIG. 1 that is the axial direction is provided on the outer periphery of the enlarged diameter portion 3a, and this longitudinal groove is formed by fitting the enlarged diameter portion 3a into the cylinder 1 so that the orifice 3c. Function as.

  Then, the tip of the small diameter portion 3b of the pipe 3 is inserted and fitted into the fitting hole 2b of the cap 2, and a pair of screw members 8 and 8 are screwed to the cap 2 from the tangential direction of the pipe 3 in parallel. The pipe 3 is fixed to the cap 2 by being inserted into the annular groove 3d, and the inside of the pipe 3 is communicated to the outside of the shock absorber D through the lateral hole 2c and released to the atmosphere. The pipe 3 can be slightly swung with respect to the cap 2 and the cylinder 1 by play between the screw members 8 and 8 and the annular groove 3d.

  As described above, when the pipe 3 is inserted into the cylinder 1 and fixed to the cap 2, the expanded diameter portion 3 a of the pipe 3 is fitted to the inner periphery of the cylinder 1, and the pipe 3 has an annular gap in the cylinder 1. The reservoir R is defined by the annular gap, and the working chamber filled with the liquid is partitioned on the upper side of the cylinder 1 in FIG.

  An annular free piston 7 is slidably inserted between the small diameter portion 3b of the pipe 3 and the inner periphery of the cylinder 1, and the free piston 7 fills the reservoir R with a liquid chamber. It is divided into L and an air chamber G in which a gas of a predetermined pressure is enclosed. An annular seal 15 is attached to the outer periphery of the lower end in FIG. 1, which is the tip of the small diameter portion 3b of the pipe 3, and the seal 15 seals between the fitting hole 2b of the cap 2 and the small diameter portion 3b. Thus, leakage of gas to the outside of the cylinder 1 is prevented.

  Further, the free piston 7 is provided with annular seals 7a and 7b on the inner periphery and the outer periphery to prevent leakage of the liquid in the liquid chamber L, and further, the air chamber side end which is the lower end in FIG. Is provided with a screw hole 7c.

  Subsequently, the piston 6 is formed in an annular shape and attached to the middle of the rod 4, and the working chamber which is partitioned by the pipe 3 on the upper side in FIG. 1 of the cylinder 1 and filled with liquid is divided into two pressure chambers R 1 and R 2. Further, it has ports 6a and 6b that communicate with the pressure chamber R1 and the pressure chamber R2.

  The piston 6 is attached to the middle of the rod 4 together with a leaf valve 9a for opening and closing the port 6a and a leaf valve 9b for opening and closing the port 6b.

  That is, when the piston 6 moves upward in FIG. 1 with respect to the cylinder 1 and the shock absorber D extends, the leaf valve 9b causes the liquid flow moving from the pressure chamber R1 to the pressure chamber R2 via the port 6b. A resistance is applied to generate a damping force in the shock absorber D. Conversely, when the piston 6 moves downward in FIG. 1 with respect to the cylinder 1 and the shock absorber D is compressed, the pressure chamber R2 moves to the pressure chamber R1. A damping force can be generated in the shock absorber D by applying resistance to the flow of liquid moving through the port 6a by a leaf valve 9a.

  Further, with this configuration, the liquid chamber L of the reservoir R communicates with the pressure chamber R2 in the working chamber through the orifice 3c, and the reservoir R connects the pressure chambers R1 and R2 to each other. Pressure is applied by the pressure in the air chamber G.

  Further, the rod 4 includes one end 4a disposed below the piston 6 in FIG. 1, one end 4a disposed above the piston 6 in FIG. 1, and the other end 4b having the same outer diameter. The screw hole 4c is provided at the upper end of the one end 4a, and the small diameter portion 4d provided at the lower end of the other end 4b is inserted into the piston 3 and screwed into the screw hole 4c, thereby holding the piston 6 in the middle. The one end 4a and the other end 4b are integrated. The rod 4 is composed of two members, one end 4a and the other end 4b, so that the piston 6 can be easily installed in the middle. However, the rod 4 and the piston 6 are manufactured integrally. May be.

  Further, the other end 4b of the rod 4 is inserted into the inside of an annular head member 10 fitted to the upper end of the cylinder 1 in FIG. The shock absorber D is mounted on the vehicle body by attaching the lower end of the cylinder 1 to the axle side of the vehicle using a mounting bracket 2a provided on the cap 2 that is screwed to the lower end of the cylinder 1 and closes the lower end of the cylinder 1 on the vehicle body side. Can be interposed between the vehicle and the axle. Note that a seal 11 seals between the cap 2 and the cylinder 1 to prevent leakage of gas to the outside of the cylinder 1.

  Further, a cover 12 that covers the upper end of the cylinder 1 in FIG. 1 is screwed onto the screw portion 1 a of the cylinder 1. Between the cover 12 and the head member 10, an annular plate-like insert metal 13 a and the cover metal 13 a are attached. A seal member 13 having a lip 13b held on the inner periphery of the insert metal 13a and slidably contacting the outer periphery of the rod 4 is interposed. The upper end of the cylinder 1 is sealed by the seal member 13 so that the liquid cylinder 1 Leakage to the outside is prevented.

  Returning, one end 4 a of the rod 4 is movably inserted into the pipe 3 inserted into the cylinder 1, and is slidable by an annular guide member 5 fixed in the enlarged diameter portion 3 a of the pipe 3. Is pivotally supported. That is, one end 4a of the rod 4 is guided by the guide member 5 installed in the enlarged diameter portion 3a of the pipe 3 and protrudes into the small diameter portion 3b, and the inside of the pipe 3 is open to the atmosphere. No pressure other than atmospheric pressure is applied to the one end 4a even if it expands and contracts.

  The guide member 5 is annular in order to allow the insertion of the one end 4a of the rod 4, and specifically, an annular main body 5a that is screwed to the inner periphery of the enlarged diameter portion 3a of the pipe 3, and an annular main body A cylindrical bearing 5b fixed to the inner periphery of 5a and slidably in contact with the outer periphery of one end 4a of the rod 4 is provided. The guide member 5 and the expanded diameter portion 3a and the reduced diameter portion 3b of the pipe 3 A seal member 14 is interposed between the boundary step 3e.

  The seal member 14 is provided on the inner periphery of the annular plate-like insert metal 14a and the insert metal 14a sandwiched between the annular body 5a and the step portion 3e of the pipe 3, and slides on the outer periphery of the one end 4a of the rod 4. The lip 14b is in contact with the outer peripheral seal 14c that is in close contact with the inner periphery of the enlarged diameter portion 3a of the pipe 3, and the seal member 14 prevents liquid leakage from the pressure chamber R2 into the pipe 3. .

  The liquid that has passed between the bearing 5b and the rod 4 flows back to the pressure chamber R2 through a through hole 5c provided in the annular body 5a, and the diameter-enlarged portion in the annular body 5a and the pipe 3 The liquid is stored in the space partitioned by the inner periphery of 3a and the step portion 3e so as not to accumulate pressure.

  As can be understood from the above description, this shock absorber D is configured as a so-called double rod type shock absorber, and there is no change in the overall volume of each pressure chamber R1, R2 when expanding and contracting, and simply a shock absorber. When D expands and contracts, the free piston 7 basically does not move in the vertical direction in FIG. That is, the reservoir R pressurizes the pressure chambers R1 and R2 that are working chambers by the internal pressure, and absorbs the change in the entire volume of the pressure chambers R1 and R2 that are working chambers due to temperature changes in the air chamber G. Volume compensation is performed, and basically volume compensation during expansion / contraction is not performed.

  That is, in this shock absorber D, the free piston 7 basically does not move up and down during expansion and contraction, so unstable frictional force between the free piston 7 and the cylinder 1 affects the pressure in the pressure chamber R2. Without giving, the shock absorber D can exhibit a stable damping force.

  Even if the pressure in the pressure chamber R2 may suddenly increase or decrease, the movement of the free piston 7 is limited by the frictional force between the free piston 7 and the cylinder 1 when the piston speed is low. When the piston speed becomes high, the inflow of the liquid into the liquid chamber L is restricted by the throttling effect of the orifice 3c, and the liquid between the liquid chamber L and the pressure chamber R2 is not used during temperature compensation. Can be limited, and the generated damping force of the shock absorber D is not affected.

  As described above, the shock absorber D is configured as a double rod type shock absorber, and the pipe 3 that is open to the atmosphere inside the cylinder 1 is inserted to form an annular reservoir R in the cylinder 1. Since one end 4a of the rod 4 is inserted into the rod 3, only the atmospheric pressure acts on both ends of the rod 4, and the pressure in the air chamber G of the reservoir R does not act. There is no reaction force.

  Therefore, according to this shock absorber D, since the rod reaction force does not occur, the pressure in the air chamber G can be set freely without being restricted by the setting of the pressure in the air chamber G. The degree of freedom in setting the damping force generated by the shock absorber and the responsiveness is dramatically increased, and the pressure in the air chamber G can be set to be optimal for the ride comfort in the vehicle, which dramatically improves the ride comfort in the vehicle. Can be improved.

  In addition, since the pipe 3 connected to the cap 2 that closes the end of the cylinder 1 is inserted into the cylinder 1 to form the annular reservoir R in the cylinder 1, The structure can be realized with a monotube, the outer diameter of the shock absorber D can be made compact, the pressure receiving area of the piston 6 can be set large, and the shock absorber D is suitable for generating a large damping force It can be.

  Further, a pipe 3 whose inside is opened to the atmosphere is inserted into the cylinder 1 so as to form an annular reservoir R in the cylinder 1, and this reservoir R is pressurized by an orifice 3 c provided in the enlarged diameter portion 3 a of the pipe 3. Since the chamber R2 communicates with the chamber R2, the configuration of the buffer D is not complicated, and the buffer D can be easily manufactured.

  Further, the guide member 5 provided in the enlarged diameter portion 3a of the pipe 3 guides the rod 4 that moves in the vertical direction in FIG. 1, and the lateral load acting on the rod 4 is increased in diameter of the guide member 5 and the pipe 3. It can be supported by the portion 3a. Therefore, even if a lateral force acts on the shock absorber D, the lateral force can be distributed and received by each member of the pipe 3 holding the head member 10, the piston 6 and the guide member 5, and the sliding portion of the rod 4 can be received. It is possible to reduce the frictional resistance of the shock absorber D and to achieve a smoother expansion and contraction of the shock absorber D.

  Further, as described above, since the pipe 3 can be slightly swung with respect to the cap 2 and the cylinder 1, the buffer D cannot be assembled due to a dimensional error of each part. There is no fear, since the pipe 3 is fixed to the cap 2 and the screw members 8 and 8 are inserted into the annular groove 3d, so that the screw members 8 and 8 are inserted into the annular groove 3d of the pipe 3. At this time, it is not necessary to position the pipe 3 in the circumferential direction, and assembly is easy.

  As described above, the shock absorber D of the present invention exhibits the excellent effects as described above. In order to inject liquid into the liquid chamber L of the shock absorber D, the following operation is performed.

  First, as shown in FIG. 2, the pipe 3 and the free piston 7 provided with the guide member 5 are assembled in the cylinder 1, and the end 4 a of the rod 4 is inserted into the guide member 5. Inject into the cylinder 1. However, when the flow path area of the orifice 3c provided on the outer periphery of the enlarged diameter portion 3a of the pipe 3 is very small, the liquid is not injected into the liquid chamber L of the reservoir R as it is, and the gas in the liquid chamber L is left as it is. Will be left behind.

  Therefore, the free piston 7 is positioned at a predetermined position with respect to the cylinder 1 by using a shock absorber assembly tool 20 for positioning the free piston 7 at a predetermined position in the cylinder 1, and the pipe 3 is connected to the cylinder 1 and the free piston 7. The volume in the liquid chamber L is increased or decreased in the manner of a syringe, and the liquid filled above the diameter-enlarged portion 3a of the pipe 3 of the cylinder 1 is moved into the liquid chamber L. Inhale.

  As shown in FIG. 2, the assembly tool 20 includes a base portion 21 that is fitted to one end of the cylinder 1, and an assembly rod 22 that is connected to the base portion 21 and can be screwed to the air chamber side end portion of the free piston 7. It is prepared for.

  The base 21 is annular so that the pipe 3 can be inserted, and includes a flange 21 a that abuts the opening end of the cylinder 1 and a hole 21 b, and the assembly rod 22 is a screw hole provided in the free piston 7. 7c, a small diameter portion 22b inserted through the hole 21b of the base portion 21, and a screw portion 22c provided at the tip of the small diameter portion 22b. The base portion 21 and the assembly rod 22 are the screw portion 22c. This is done by a nut 23 that is screwed onto the nut.

  The assembly tool 20 pushes the base 21 into the cylinder 1 until the flange 21 a contacts the opening end of the cylinder 1 in a state where the assembly rod 22 is screwed into the free piston 7 and integrated with the free piston 7. The free piston 7 can be positioned at a predetermined position in the cylinder 1, and the pipe 3 is reciprocated in the vertical direction while the free piston 7 is positioned at the predetermined position with respect to the cylinder 1 by the assembly tool 20. It can be moved.

  Then, by moving the pipe 3 upward, the liquid sucked into the liquid chamber L through the orifice 3c is heavy, so that the liquid is stored below the liquid chamber L. The upper gas is discharged from the liquid chamber L through the orifice 3c, and the reciprocating motion is repeated, so that the liquid chamber L is eventually filled with only the liquid, and this assembly tool 20 is used. Thus, the liquid can be easily injected into the liquid chamber L.

  After the liquid chamber L is filled with only the liquid, the free piston 7 is positioned at a predetermined position in the cylinder 1 with the assembly tool 20, and this time the cylinder 1 is injected at the time of liquid injection into the liquid chamber L. The liquid is injected into the cylinder 1 so that the total amount of the liquid together with the volume of the liquid injected into the cylinder 1 matches the volume of the pressure chambers R1, R2 and the liquid chamber L, and the rod 4 provided with the piston 6 is inserted into the cylinder 1. To go.

  In this way, the pressure chamber R2 is compressed by the piston 6 and the liquid tries to flow into the liquid chamber L. However, since the free piston 7 is positioned by the assembly tool 20 and is not moved, the liquid remains in the pressure chamber. As R2 is compressed, it only moves to the pressure chamber R1, and the volume of the liquid chamber L is not changed during assembly of the buffer D, and the buffer D can be manufactured as designed. is there.

  In addition, since the shock absorber D can be manufactured as designed by the assembly tool 20, the performance of the shock absorber D does not vary from product to product, and the product yield is improved.

  In order to facilitate the operation of reciprocating the pipe 3 in the vertical direction, a screw portion 3f is provided on the inner periphery of the lower end in FIG. 1 of the small diameter portion 3b of the pipe 3, and a bolt (not shown) is attached to the screw portion 3f. The pipe 3 can be reciprocated by screwing and using the bolt as a handle.

  Further, in the above description, the pipe 3 is reciprocated in the vertical direction to inject the liquid into the liquid chamber L. However, the pipe 3 is fixed with respect to the cylinder 1 and the free piston 7 is moved to the cylinder 1. The free piston 7 is reciprocated up and down with respect to the cylinder 1 and the pipe 3 by using a shock absorber assembly tool 20 positioned at a predetermined position in the inside, and the volume in the liquid chamber L is increased or decreased in the manner of a syringe. Thus, the liquid filled above the enlarged diameter portion 3a of the pipe 3 of the cylinder 1 may be sucked into the liquid chamber L.

  Furthermore, as described above, the free piston 7 connects the liquid chamber L and the air chamber G of the reservoir R so that the shock absorber D can be used as a so-called upright shock absorber in which the cylinder 1 is installed on the axle side. In the case of a so-called inverted type in which the cylinder 1 side is attached to the vehicle body side and the other end 4b of the rod 4 is attached to the axle side, the shock absorber D in FIG. Therefore, the air chamber G is inevitably disposed on the cap 2 side of the cylinder 1 to enable gas-liquid separation, and the free piston 7 may be omitted, and the operational effects of the present invention are not lost. In other words, the provision of the free piston 7 makes it possible to use the shock absorber D whether it is upright or inverted. Further, in the shock absorber set to the inverted type, the free piston 7 can be omitted, and the number of parts can be reduced.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a longitudinal cross-sectional view of the shock absorber in one embodiment. It is a figure which shows the process of inject | pouring a liquid into the liquid chamber of the buffer in one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 1a, 1b Cylinder thread part 2 Cap 2a Cap mounting bracket 2b Cap fitting hole 2c Cap side hole 3 Pipe 3a Pipe expanded diameter part 3b Pipe small diameter part 3c Pipe orifice 3d Pipe annular groove 3e Step part 3f in the pipe Screw part 4 in the pipe 4 Rod 4a One end 4b of the rod 4c The other end 4c of the rod Screw hole 4d Small diameter part 5 Guide member 5a Annular main body 5b on the guide member A bearing 5c on the guide member A through hole 6 on the annular main body Piston 6a, 6b Port 7 Free piston 7a, 7b Annular seal 7c in free piston Screw hole 8 in free piston Screw member 9a, 9b Leaf valve 10 Head member 11, 15 Seal 12 Cover 13, 1 Seal member 13a, 14a Insert metal 13b, 14b in seal member Lip 20 in seal member Assembly tool 21 Base 21a Flange 21b in base Base hole 22 Assembly rod 22a, 22c Screw part 22b in assembly rod Small diameter part 23 in assembly rod Assembly tool Nut D Buffer G Air chamber L Fluid chamber N Nut R Reservoir R1, R2 Pressure chamber S Suspension spring receiver

Claims (4)

A cylinder, a cap that closes one end of the cylinder, a large-diameter portion and a small-diameter portion, the large-diameter portion is fitted into the cylinder, the small-diameter portion is connected to the cap, and the inside communicates with the outside, A pipe that forms a reservoir composed of a liquid chamber and an air chamber, a rod that is inserted into the cylinder and one end of which is inserted into the pipe, and a rod that is fixed to the inner peripheral side of the expanded portion of the pipe An annular guide member that guides one end of the cylinder, a piston that is provided in the middle of the rod and that separates the two pressure chambers in the cylinder, and is provided in an enlarged diameter portion of the pipe to communicate between the liquid chamber and the pressure chamber A shock absorber comprising an orifice. A cylinder, a cap that closes one end of the cylinder, a large-diameter portion and a small-diameter portion, the large-diameter portion is fitted into the cylinder, the small-diameter portion is connected to the cap, and the inside communicates with the outside, A pipe that forms a reservoir between them, a rod that is inserted into the cylinder and one end of which is inserted into the pipe, and an annular guide that is fixed to the inner peripheral side of the enlarged diameter portion of the pipe and guides one end of the rod The piston is provided between the member and the rod and separates the two pressure chambers in the cylinder, and is slidably inserted between the small diameter portion of the pipe and the cylinder to partition the reservoir into a liquid chamber and an air chamber. A shock absorber comprising: an annular free piston, and an orifice provided in a diameter-expanded portion of the pipe and communicating the liquid chamber and the pressure chamber. The cap is provided with a fitting hole that communicates with the outside and into which the tip of the small diameter portion of the pipe is fitted. The shock absorber according to claim 1 or 2, wherein the pipe is fixed to the cap with a pair of screw members that are screwed and inserted into the annular groove of the pipe. A pipe having a cylinder, a cap that closes one end of the cylinder, an enlarged diameter portion and a small diameter portion, the enlarged diameter portion is fitted into the cylinder, and the small diameter portion is connected to the cap to form a reservoir between the cylinder A rod that is inserted into the cylinder and has one end side inserted into the pipe, an annular guide member that is fixed to the inner peripheral side of the expanded diameter portion of the pipe and guides one end of the rod, and is provided in the middle of the rod A piston that separates two pressure chambers in the cylinder, an annular free piston that is slidably inserted between the small diameter portion of the pipe and the cylinder, and divides the reservoir into a liquid chamber and an air chamber, and a pipe The free piston is positioned at a predetermined position in the cylinder in the step of injecting liquid into the liquid chamber of the shock absorber provided with the orifice that is provided in the enlarged diameter portion of the shock absorber and has an orifice that communicates the liquid chamber and the pressure chamber. An impactor assembly tool comprising: a base portion that fits into one end of a cylinder; and an assembly rod that is connected to the base portion and can be screwed into an air chamber side end portion of a free piston. Assembly tool.

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