JP5831986B2 - Vehicle shock absorber - Google Patents

Description

  The present invention relates to an improvement of a shock absorber for a vehicle.

  Conventionally, in a shock absorber for a vehicle, for example, a cylinder, a cylinder, and an extension working chamber and a pressure working chamber are inserted into the cylinder so as to be slidable. A piston that is divided into a cylinder, a piston rod that is movably inserted into the cylinder and holds the piston in the center, an outer cylinder that is connected to the lower end of the cylinder, and an insertion in the lower end side of the piston rod that is accommodated in the outer cylinder And a free piston that is slidably inserted into both the outer cylinder and the inner cylinder and defines a liquid chamber and an air chamber between the outer cylinder and the inner cylinder. (For example, refer to Patent Document 1).

  As a method for improving the damping force generation responsiveness of the vehicle shock absorber, increasing the pressure in the cylinder can be mentioned. Generally, a liquid has elasticity, and when a gas is dissolved in the liquid, the liquid column rigidity is low. When the liquid column rigidity is lowered, the liquid acts as a spring at the start of expansion and contraction of the vehicle shock absorber, and the rising of the damping force tends to be delayed in time. Therefore, when the pressure in the cylinder is increased to pressurize the liquid and the liquid column rigidity is increased, the damping force generation responsiveness is improved.

  However, when the cylinder internal pressure is set high with a single rod type shock absorber, the shock absorber is urged so as to always expand due to the cylinder internal pressure, so that the rod reaction force becomes large and the ride comfort in the vehicle is impaired. Result.

  On the other hand, in the above-described conventional vehicle shock absorber, since the piston rod is a so-called double rod type shock absorber in which both the extension side working chamber and the pressure side working chamber are inserted, the one rod Like a type shock absorber, even if the pressure in the air chamber is set high and the cylinder pressure is increased, the rod reaction force does not increase, so while increasing the liquid column rigidity and improving the damping force generation response, It is possible to achieve both improvement in damping force generation response and riding comfort without impairing the riding comfort in the vehicle.

JP 2010-71413 A (FIG. 1)

  Here, in the case of a vehicle shock absorber used in vehicle experiments or motor sports, it may be required to quickly adjust the damping force characteristic (damping characteristic) with respect to the expansion / contraction speed. In many cases, adjustment of the attenuation characteristic is required.

  However, the conventional vehicle shock absorber employs a structure in which a leaf valve that is a damping valve is stacked on the piston portion, and when adjusting the damping characteristics, the piston is pulled out from the cylinder at one end, It is necessary to perform a complicated and time-consuming work such as replacing the leaf valve, changing the number of stacked layers, and returning the piston together with the leaf valve into the cylinder while filling the cylinder with hydraulic oil.

  Therefore, the present invention was devised to improve the above-described problems, and an object of the present invention is to provide a vehicular shock absorber capable of easily adjusting the damping characteristics in a short time. That is.

To solve the problems described above, problems solving means of this invention, the cylinder and a piston that is inserted slidably into the cylinder, the extension side working chamber partitioned by the piston within the cylinder and the compression side and working chamber, the liquid chamber and a partition wall which partitions a valve case having a hollow portion provided on a side opening outwardly, in the secondary working chamber and the auxiliary liquid chamber are housed in the hollow portion of the cylinder When the communication path leading from one of the extension side working chamber and the pressure side working chamber to the auxiliary working chamber, a liquid chamber passage leading from the liquid chamber to said auxiliary fluid chamber, said auxiliary provided on the partition wall the liquid with allowing the damping passage connecting the working chamber and the auxiliary liquid chamber, only the flow of the liquid toward housed within the valve case from the damping passage is opened and closed the auxiliary hydraulic chamber to said auxiliary fluid chamber A damping valve that resists the flow of The vehicle shock absorber comprising, a lid for closing the opening of the hollow portion, and a fixing member for fixing the partition wall to the lid, the lid, the fixing member which is housed in the hollow portion, the partition wall, The volume occupied in the valve case of the damping valve and the fixed member fixed to the fixing member is in the hollow portion of the valve case among the outlet ends to the hollow portion of the communication path and the liquid chamber passage . at the outlet end is positioned on the opening end side, characterized in that it is set to be smaller than the hollow interior volume of the opening end side of the edge of the opening end side.

  In this vehicle shock absorber, even if the valve case is provided on the side of the cylinder and the lid, the fixing member, the partition wall, the damping valve and the fixed member are removed from the inside of the valve case, the extension side working chamber, Since there is no risk of gas entering the pressure side working chamber and the liquid chamber, the damping valve can be replaced easily and in a short time.

  As described above, according to the vehicle shock absorber of the present invention, the attenuation characteristic can be easily adjusted in a short time.

It is a longitudinal section of a shock absorber for vehicles in one embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, a vehicle shock absorber D according to an embodiment includes a cylinder 1, a piston 3 that is slidably inserted into the cylinder 1, and an extension defined by the piston 3 in the cylinder 1. A side working chamber R1, a pressure side working chamber R2, a liquid chamber L, a valve case 4 provided on the side of the cylinder 1 and having a hollow portion 4a that opens outward, and is accommodated in the valve case 4 and is A partition wall 5 that is divided into a working chamber 6 and a sub liquid chamber 7, a communication path 4 b that leads from the pressure side working chamber R 2 to the sub working chamber 6, a liquid chamber passage 4 c that leads from the liquid chamber L to the sub liquid chamber 7, and a partition wall 5 Attenuation passage 8 that is provided to communicate the sub-actuating chamber 6 and the sub-liquid chamber 7, and a liquid flow that is accommodated in the valve case 4 and opens and closes the damping passage 8 and moves from the sub-actuating chamber 6 to the sub-liquid chamber 7. Pressure side bar as a damping valve that allows only the flow and provides resistance to liquid flow , A lid 31 that closes the opening of the hollow portion 4a, and a fixing member 32 that fixes the partition wall 5 to the lid 31, and is interposed between a vehicle body and an axle (not shown). It is mounted and exerts a damping force during expansion and contraction to suppress the vibration of the vehicle body.

  In addition, in the case of the vehicle shock absorber D in the present embodiment, in addition to the above-described configuration, the pressurizing means P that pressurizes the liquid chamber L, and the expansion side passage that communicates the expansion side working chamber R1 and the pressure side working chamber R2. 9, the suction passage 10 that communicates the extension side working chamber R1 and the liquid chamber L, and opens and closes the extension side passage 9 to allow only the flow of liquid from the extension side working chamber R1 to the pressure side working chamber R2. An expansion side valve 12 that gives resistance to the flow, and a suction check valve 13 that is provided in the middle of the suction passage 10 and allows only the flow of liquid from the liquid chamber L toward the expansion side working chamber R1 are provided.

  Hereinafter, each member of the vehicle shock absorber D will be described in detail. In this embodiment, the cylinder 1 is accommodated in an outer tube 2 disposed on the outer peripheral side, and a liquid chamber L is provided in the outer tube 2 and below the cylinder 1. That is, the outer tube 2 is longer than the cylinder, and in this example, the liquid chamber L is provided below the extension side working chamber R1 and the pressure side working chamber R2. As described above, the outer periphery of the cylinder 1 is covered with the outer tube 2, and in this case, an annular gap is formed between the cylinder 1 and the outer tube 2. A piston 3 is slidably inserted into the cylinder 1, and the cylinder 1 is partitioned into an upper extension side working chamber R1 and a lower pressure side working chamber R2 in FIG.

  The cylinder 1 has a surface that is surface-treated so that it can slide smoothly with the piston 3. In this way, since the surface treatment of the cylinder 1 shorter than the outer tube 2 may be performed, the surface treatment of the long outer tube 2 does not have to be performed, so that the processing cost can be reduced, and the horizontal direction in the figure input from the piston 3 Therefore, it is possible to use a light and relatively soft metal for the outer tube 2.

  The piston 3 has an annular shape and is fixed in the middle of the piston rod 15. Specifically, the piston rod 15 is composed of an upper portion 15a and a lower portion 15b, and is integrally formed by screwing a screw shaft 15c provided at the lower end of the upper portion 15a into a screw hole 15d provided at the upper end of the lower portion 15b. The piston 3 is fixed between the upper portion 15a and the lower portion 15b. In the present embodiment, the vehicle shock absorber D is a so-called double rod type in which the piston 3 is fixed to the middle of the piston rod 15 and the upper end and the lower end of the piston rod 15 protrude from the outer tube 2 to the outside. However, the lower rod 15b of the piston rod 15 may be abolished, and the piston 3 may be fixed to the lower end of the upper portion 15a.

  Returning, the piston 3 divides the inside of the cylinder 1 into an extension side working chamber R1 and a pressure side working chamber R2, and includes an extension side passage 9 that communicates the extension side working chamber R1 and the pressure side working chamber R2. . An extension side valve 12 that is an annular leaf valve that opens and closes the lower end of the extension side passage 9 is stacked on the lower end of the piston 3 in FIG. The expansion side valve 12 is directed toward the pressure side working chamber R2 where the liquid is compressed from the expansion side working chamber R1 in which the liquid is compressed in the expansion side passage 9 when the piston 3 moves upward in FIG. When flowing, the valve is opened to give resistance to the flow of the liquid. On the other hand, at the time of contraction operation, the expansion side passage 9 is closed to prevent the flow of liquid from the compression side working chamber R2 toward the expansion side working chamber R1.

  It should be noted that the expansion side valve 12 only needs to allow the flow of liquid from the expansion side working chamber R1 to the compression side working chamber R2 and provide resistance to the flow of the liquid, so that it may be a damping valve other than the leaf valve. It may be a combination of a check valve and a valve that allows two-way passage, such as a choke or an orifice, and a structure that includes a spring that biases the back of the leaf valve toward the piston 3 side is adopted. Also good.

  The outer tube 2 has an upper small-diameter portion 2a provided with a small inner diameter on the upper side, a female screw portion 2b provided on the inner periphery of the opening in the upper part of FIG. 1 with respect to the upper small-diameter portion 2a, and a lower inner periphery with a small diameter. A lower small-diameter portion 2c provided, an annular convex portion 2d provided below the lower small-diameter portion 2c and projecting toward the inner peripheral side, an inner peripheral screw portion 2e provided on the inner periphery of the annular convex portion 2d, A valve case integrated with a male screw portion 2f provided on the outer periphery of the lower end, a perforation 2g that opens from the upper end step portion of the lower small diameter portion 2c and communicates with the lower end step portion of the annular convex portion 2d, and protrudes sideways. 4 and an outer peripheral screw portion 2 h provided on the outer periphery and above the valve case 4.

The male screw portion 2f, the bracket 61 can be connected is screwed A Songs over tube 2 to the axle side (not shown) of the vehicle. An annular suspension spring receiver 14 is screwed onto the outer peripheral screw portion 2h. The suspension spring receiver 14 supports a suspension spring S that supports the vehicle body of the vehicle, and holds the suspension spring in cooperation with an upper suspension spring receiver 60 connected to the upper end of the piston rod 15. It is supposed to be. In this case, if the suspension spring 14 is within the axial installation range of the outer peripheral screw portion 2h, the axial mounting position with respect to the outer tube 2 can be changed, but the suspension spring 14 is fixedly attached to the outer tube 2. It may be made like.

  The outer tube 2 is longer than the cylinder 1, and an annular rod that pivotally supports the piston rod 15 that is movably inserted into the cylinder 1 on the upper side 15 a side in FIG. A guide 16 is fitted. Further, an annular rod guide 17 that pivotally supports the piston rod 15 on the lower portion 15b side in FIG. 1 is fitted to the lower small diameter portion 2c of the outer tube 2.

The rod guide 16 is provided at a lower portion and provided with a cylindrical socket portion 16a having a notch 16b, and is attached to the outer periphery and closely contacts the inner periphery of the upper small-diameter portion 2a. And a seal ring 16c for sealing. An annular suction check valve 13 is accommodated in the inner periphery of the socket portion 16a. In addition, an annular valve fixing member 18 is attached to the socket portion 16a below the suction check valve 13. The valve fixing member 18, which the port 18a penetrating in the axial direction, and a tubular fitting portion 18b to be fitted in the socket portion 16a to the outer periphery, the lower side of the inner periphery of the upper end opening end of the cylinder 1 Mated. As described above, when the valve fixing member 18 is fitted to the rod guide 16 and the cylinder 1, the outer periphery of the suction check valve 13 is held between the fitting portion 18 b of the valve fixing member 18 and the rod guide 16. Since the suction check valve 13 is fixed on the outer peripheral side as described above, bending of only the inner periphery is allowed. The suction check valve 13 blocks the communication between the port 18a and the notch 16b leading to the gap between the cylinder 1 and the outer tube 2 in a state where the inner periphery is in close contact with the rod guide 16. 16b communicates with the port 18a. The rod guide 17 has a hole 17a that is annular and communicates from the upper end to the outer periphery in FIG.

  Further, an annular seal member 19 that seals between the rod guide 16 and the piston rod 15 and a spacer 39 are stacked above the rod guide 16, and the inner periphery of the lower small diameter portion 2 c of the outer tube 2 is laminated. An annular seal member 20 and a spacer 40 for sealing between the piston rod 15 and the outer tube 2 are accommodated between the annular protrusion 2d and the rod guide 17.

  Then, inside the outer tube 2, the spacer 40, the seal member 20, the rod guide 17, the cylinder 1, the valve fixing member 18, the suction check valve 13, the rod guide 16, the seal member 19 and the spacer 39 are accommodated in this order. When a nut 21 having a screw portion on the outer periphery is screwed onto the screw portion 2b, each member housed in the outer tube 2 is sandwiched between the nut 21 and the annular convex portion 2d and fixed to the outer tube 2. In this way, the seal members 19 and 20 and the seal ring 16c provide a tight seal between the piston rod 15 and the outer tube 2, and the extension side working chamber R1 and the pressure side working chamber R2 are kept liquid tight. Yes.

  In addition, a cylindrical rod insertion cylinder 22 is screwed onto an inner peripheral screw portion 2 e provided on the inner periphery of the annular convex portion 2 d of the outer tube 2. The rod insertion cylinder 22 has a cap 24 fitted to the inner periphery of the outer tube 2 at the lower end, allows the lower portion 15b of the piston rod 15 to be inserted, and allows the piston rod 15 to move up and down with respect to the outer tube 2. Yes.

  When the cylinder 1 is accommodated and fixed in the outer tube 2 as described above, an annular gap is formed between the inner surface of the outer tube 2 between the upper small diameter portion 2a and the lower small diameter portion 2c and the outer surface of the cylinder 1. Is formed. The gap communicates with a liquid chamber L provided below the outer tube 2 by a perforation 2g that opens from the upper end step portion of the lower small diameter portion 2c of the outer tube 2 and communicates with the lower end step portion of the annular convex portion 2d. Therefore, in this case, a gap formed between the cylinder 1 and the outer tube 2, and a suction passage 10 that connects the expansion side working chamber R1 and the liquid chamber L by the port 18a, the notch 16b, and the perforation 2g are formed. Yes. In addition, the clearance gap formed between the cylinder 1 and the outer tube 2 is not restricted to an annular clearance, and a shape is not ask | required.

  The liquid chamber L is defined by an annular free piston 23 slidably in contact with both the inner circumference below the annular projection 2d of the outer tube 2 and the outer circumference of the rod insertion cylinder 22 described above. The gap between the outer tube 2 and the rod insertion cylinder 22 is closed by an annular cap 24 provided at the lower end of the rod insertion cylinder 22, and the free piston 23 cooperates with the cap 24 to An air chamber G is defined between the tube 2 and the rod insertion cylinder 22. The pressure in the air chamber G presses the free piston 23 upward in FIG. 1 to pressurize the liquid chamber L, thereby forming a gas spring as urging means.

  That is, in this embodiment, the pressurizing means P is a free piston 23 that is slidably inserted into the outer tube 2 and an urging means that urges the free piston 23 toward the liquid chamber L. And a gas spring. The cap 24 is provided with an airway 24a leading to the air chamber G, and the air chamber G is kept airtight by closing the airway 24a with a valve 24b. The pressure in the air chamber G can be adjusted by supplying gas to the air chamber G via the air passage 24a or discharging the gas from the air chamber G. In the vehicle shock absorber D, the gas chamber G and the gas constitute a gas spring to pressurize the liquid chamber L, and the pressure of the liquid chamber L is actuated on the extension side through the suction passage 10 described above. Since it propagates to the chamber R1 and the pressure side working chamber R2, the inside of the cylinder 1 can be pressurized. In this embodiment, the liquid chamber L is pressurized with a gas spring. In addition to the gas spring, a spring other than the gas spring such as a coil spring may be used as the urging means. In addition, a metal bellows or diaphragm filled with gas in the liquid chamber L may be accommodated, and this may be used as a pressurizing means. When the metal bellows or free piston 23 is used, the gas inside You may make it provide springs other than a spring. By making the urging means a gas spring that pressurizes the liquid chamber L with the gas enclosed in the air chamber G partitioned by the free piston 23, not only the urging force in the urging means can be easily adjusted, but also metal There is an advantage that the vehicle shock absorber D can be reduced in weight as compared with those using a coil spring or the like.

  Subsequently, the valve case 4 is provided on the side of the outer tube 2. In this embodiment, the valve case 4 includes a hollow portion 4 a that opens downward. The hollow portion 4 a It is arranged below the extension side working chamber R1 and the pressure side working chamber R2 in the axial direction. In this case, the valve case 4 is integrated on the side of the outer tube 2 and is a single component. The valve case 4 may be configured as a separate part from the outer tube 2 and integrated with the outer tube 2. Further, the opening of the valve case 4 is closed by a lid 31, and a shaft-like fixing member 32 that is screwed into the lid 31 and fixes the partition wall 5 and the pressure side valve 11 to the valve case 4 is provided. Yes.

  Specifically, the valve case 4 includes a hollow portion 4a that opens from the lower end, a communication path 4b that communicates the hollow portion 4a and the pressure side working chamber R2, and a liquid chamber passage 4c that communicates the hollow portion 4a and the liquid chamber L. It has. Specifically, the communication path 4b faces the open end of the hole 17a on the outer periphery of the rod guide 17, and communicates with the pressure side working chamber R2 through the hole 17a. In this embodiment, the liquid chamber passage 4c communicates with the upper end of the liquid chamber L, and the outlet end on the liquid chamber L side is not disposed within the sliding range of the free piston 23. The seal ring 50 mounted on the outer periphery is not squeezed by the outlet end.

  In this embodiment, the outlet end on the hollow portion 4a side of the communication path 4b is disposed below the lower end of the extension side working chamber R1 and the lower end of the compression side working chamber R2. Therefore, in this embodiment, the hollow portion 4a is opened downward, and the vehicle shock absorber D is set to the posture reversed from the posture shown in FIG. 1 so that the opening of the hollow portion 4a is directed upward. Even if the lid 31 is removed or the hollow part 4a is opened to the outside, the extension side working chamber R1 and the pressure side action are provided if the liquid level in the hollow part 4a is above the outlet end on the hollow part side of the communication path 4b. An external gas does not enter the chamber R2. In other words, when the vehicular shock absorber D is set to the upside down posture from the posture shown in FIG. 1 and the opening of the hollow portion 4a is directed upward, the outlet end of the connecting passage 4b on the hollow portion 4a side is the extension side working chamber R1. And the pressure side working chamber R2 are disposed above the gas passage from the communication path 4b to the extension side working chamber R1 and the pressure side working chamber R2. In this embodiment, since the liquid chamber L is partitioned from the air chamber G by the free piston 23, the free piston in a state where the vehicle shock absorber D is changed from the posture shown in FIG. 23 moves to the lower limit of movement of the liquid chamber L and the movement is restricted, or if the movement of the free piston 23 is restricted in advance, the liquid level of the liquid in the hollow portion 4a is changed to the liquid chamber passage 4c. As long as it is above the outlet end on the hollow portion 4a side, the gas does not enter the liquid chamber L. Thus, when the member which isolate | separates air chamber G and liquid chamber L, such as free piston 23, metal bellows, and a diaphragm, is restrained so that the volume of liquid chamber L may not change, when lid 31 is removed The gas can be prevented from entering the liquid chamber L through the hollow portion 4a.

  The opening direction of the hollow portion 4a can be arbitrarily set. For example, even when the hollow portion 4a opens in the lateral direction or upward in FIG. 1, the opening of the hollow portion 4a is directed upward. In this state, the outlet end on the hollow portion 4a side of the communication path 4b may be disposed above the upper end of the extension side working chamber R1 and the upper end of the pressure side working chamber R2. By doing so, external gas can be prevented from entering the extension side working chamber R1 and the pressure side working chamber R2. When the liquid chamber L is not provided with a member such as a free piston 23 that separates the air chamber G from the outlet end of the liquid chamber passage 4c on the hollow portion 4a side, the liquid chamber passage 4c is disposed at least above the lower end of the liquid chamber L. Consideration should be given to prevent intrusion. As described above, the outlet end and the extension side of the hollow portion 4a side of the communication path 4b according to the opening direction of the hollow portion 4a with respect to the valve case 4 and the presence / absence of a member that partitions the liquid chamber L from the air chamber G. The positional relationship between the working chamber R1 and the pressure-side working chamber R2 and the positional relationship between the outlet end of the liquid chamber passage 4c on the hollow portion 4a side and the liquid chamber L may be determined so as to prevent gas intrusion.

  A partition wall 5 is fitted in the hollow portion 4 a of the valve case 4. This partition wall 5 is in contact with the inner surface of the hollow portion 4a of the valve case 4 so that the inside of the hollow portion 4a is divided into an auxiliary working chamber 6 on the upper side in FIG. 1 and an auxiliary liquid chamber 7 on the lower side in FIG. It is partitioned. The sub working chamber 6 communicates with the pressure side working chamber R2 through the communication path 4b and the hole 17a, and the sub liquid chamber 7 communicates with the liquid chamber L through the liquid chamber passage 4c. .

  The partition wall 5 is annular and includes an attenuation passage 8 that communicates the sub working chamber 6 and the sub liquid chamber 7, and a compensation passage 33 that communicates the sub working chamber 6 and the sub liquid chamber 7. The partition wall 5 is fixed to the valve case 4 by being mounted on the outer periphery of the fixing member 32 accommodated in the valve case 4.

Further, the auxiliary liquid chamber surface, which is the lower surface in FIG. 1 of the partition wall 5, is a damping valve composed of an annular leaf valve that is fixed to the outer periphery of the fixing member 32 and opens and closes the lower end opening in FIG. Compensation check comprising a pressure side valve 11 and an annular leaf valve which is fixed to the outer periphery of the fixing member 32 and opens and closes the upper end opening in FIG. Valves 34 are stacked. Note that the pressure side valve 11 as a damping valve is only required to permit only the flow of liquid from the pressure side working chamber R2 to the liquid chamber L and provide resistance to the flow. It may be a combination of a check valve and a valve that allows bidirectional passage, such as a choke or an orifice, and a structure that includes a spring that biases the back of the leaf valve toward the partition wall 5 side. It may be adopted. Further, the pressure side valve 11 does not block the upper end opening in FIG. 1 of the compensation passage 33, and the compensation check valve 34 also does not block the lower end opening in FIG. 1 of the damping passage 8. .

  In this case, the lid 31 includes a core portion 31a to which the lower end of the fixing member 32 is screwed, a flange 31b provided on the outer periphery on the upper end side of the core portion 31a, and a cylindrical outer tube portion provided on the outer periphery of the flange 31b. 31c and an outer periphery of the lower end of the outer cylindrical portion 31c are provided with a flange-like fitting portion 31d that fits into the inner periphery of the opening at the lower end of the valve case 4, that is, the lower end inner surface of the hollow portion 4a. A screw part 31e is provided on the lower side, and is screwed to the inner periphery of the lower end of the valve case 4. As described above, when the lid 31 is attached to the valve case 4 and accommodated in the hollow portion 4a, an annular gap is formed between the outer cylindrical portion 31c and the valve case 4 which are above the fitting portion 31d. Is done. The core 31a of the lid 31 is provided with a screw hole 31f drilled from the upper end side, and the lower end of the fixing member 32 is screwed into the screw hole 31f. In addition, the outer peripheral surface of the fitting part 31d is provided so that it may gradually expand from the outer cylinder part 31c, and the upper end of the fitting part 31d is provided with the curved surface. Further, in this embodiment, if the outer peripheral shape of the lower end of the core portion 31a of the lid 31 is set to a shape other than a perfect circle, the outer periphery of the lower end can be gripped by a tool (not shown), and the valve of the lid 31 Desorption to the case 4 is facilitated.

  Subsequently, the fixing member 32 includes a shaft portion 32a, a flange 32b provided at the upper end of the shaft portion 32a in FIG. 1, and a screw portion 32c provided at the outer periphery of the lower end in FIG. The screw portion 32c is screwed into the screw hole 31f and integrated with the lid 31.

  In addition to the partition wall 5 and the pressure side valve 11, an annular spacer 41, a compensation check valve 34, a spacer 42, a cylindrical spacer 43, and a spacer 44 are fixed to the outer periphery of the shaft portion 32 a of the fixing member 32. Is mounted together with the partition wall 5 and the pressure side valve 11.

  An annular spacer 41, a compensation check valve 34, a partition wall 5, a pressure side valve 11, a spacer 42, a cylindrical spacer 43, and a spacer 44 are sequentially attached to the outer periphery of the shaft portion 32 a of the fixing member 32, and the screw of the lid 31 is attached. By screwing the screw portion 32c into the hole 31f, all members housed in the valve case 4 are assembled. These assembled members are fixed to the valve case 4 while being accommodated in the hollow portion 4 a by screwing the lid 31 to the valve case 4. The spacers 42 and 44 and the spacer 43 can be eliminated or the number of installation can be increased or decreased depending on the axial length of the valve case 4. A seal ring 45 is mounted on the outer periphery of the fitting portion 31d of the lid 31, and the seal ring 45 is in close contact with the valve case 4 so that the hollow portion 4a is kept liquid-tight.

  Further, in the vehicle shock absorber D, the lid 31, the fixing member 32, the partition wall 5, the pressure side valve 11, and the above-described fixed object are provided in the valve case 4 filled with liquid, that is, in the hollow portion 4a. When the members are accommodated, the volume by which these members push away the liquid in the valve case 4 is such that the opening of the hollow portion 4a out of the outlets on the hollow portion 4a side to the valve case 4 of the communication path 4b and the liquid chamber passage 4c. It is set to be smaller than the inner volume of the hollow portion on the opening end side than the edge on the opening end side at the outlet end arranged on the end side. That is, in this case, the volume occupied by the lid 31, the fixing member 32, the partition wall 5, the pressure side valve 11, and the fixed member described above in the valve case 4 is the hollow opening end of the outlet end of the liquid chamber passage 4 c of the valve case 4. The inner volume of the hollow portion in the range X from the lower end edge in FIG. 1 which is the side edge to the lower end opening end in FIG. 1 of the hollow portion 4a is made smaller. The volume occupied by the lid 31, the fixing member 32, the partition wall 5, the pressure side valve 11, and the fixed member described above in the valve case 4 is a volume by which these members push the liquid in the valve case 4 as described above. Therefore, although there are a plurality of holes (not shown) provided in the lid 31 from the lower end side in FIG. 1, these holes do not affect the occupied volume.

  Therefore, even if this vehicle shock absorber D is turned upside down from the state shown in FIG. 1 so that the opening of the valve case 4 faces upward, and each member assembled together with the lid 31 is removed from the valve case 4, As described above, the relationship between the volume of each member assembled together with the lid 31 and the volume below the liquid chamber passage 4c of the valve case 4 does not spout the liquid in the pressure side working chamber R2 from the communication path 4b. Therefore, the liquid level in this state (the state in which it is turned upside down from FIG. 1) is always arranged above the upper end of the liquid chamber passage 4c. The outside gas does not enter the pressure side working chamber R2 and the liquid chamber L through the path 4b.

  Then, after changing the outer diameter of the leaf valve of the compression side valve 11 and the number of stacked layers, the lid 31 is assembled again, the valve case 4 is filled with the liquid, and the assembly from the fixed member 32 side to the valve case 4 is completed. As each member is inserted, the liquid pushed away by each member overflows from the valve case 4 and can be accommodated and fixed in the valve case 4 without gas mixing.

  The lid 31 that closes the valve case 4 has a tapered surface 31g on the outer periphery of the boundary between the flange 31b and the outer cylinder portion 31c, and is considered so that gas does not accumulate. In addition, an annular gap is formed between the outer cylinder portion 31c above the fitting portion 31d of the lid 31 and the valve case 4, and the upper end of the fitting portion 31d of the lid 31 has a curved surface. Therefore, at the stage where each assembled member is inserted into the valve case 4, the liquid pushed away by each member is smoothly discharged out of the valve case 4 through the outer periphery of the lid 31, and the gas is discharged into the valve case. It is possible to reliably prevent the occurrence of a situation that is left behind. It should be noted that the effect of reliably preventing gas from remaining in the valve case 4 in the operation of inserting each assembled member into the valve case 4 is that the upper end outer peripheral shape of the fitting portion 31d is a tapered surface. You can also get it. That is, the angle formed by the upper end surface of the fitting part 31d and the outer periphery of the outer cylinder part 31c may be 90 degrees or more.

  In the vehicle shock absorber D, the valve case 4 is provided on the side of the cylinder 1, and the lid 31, the fixing member 32, the partition wall 5, the pressure side valve 11 and the fixed member are removed from the valve case 4. However, since there is no risk of gas entering the pressure side working chamber R2 and the liquid chamber L, the pressure side valve 11 as a damping valve can be easily and quickly replaced. The attenuation characteristics on the side can be adjusted easily and in a short time.

  Note that either the communication path 4 b or the liquid chamber path 4 c may be disposed on the lower side of the valve case 4. Further, by disposing the liquid chamber L below the compression side working chamber R2 and the extension side working chamber R1 in FIG. 1, only the valve case 4 is disposed on the side of the cylinder 1 of the vehicle shock absorber D. Therefore, there is an advantage that the suspension spring receiver 14 can be easily attached to the vehicle shock absorber D, and since the opening of the hollow portion 4a is directed downward, when the damping valve is attached to and detached from the hollow portion 4a, Since the damping valve and other members assembled therewith do not interfere with the suspension spring receiver 14, the damping valve can be adjusted more easily. However, the liquid chamber L should be arranged on the side of the cylinder 1. The opening direction of the hollow portion 4a can be arbitrarily set as described above.

Further, in this embodiment, septum wall 5 which is integrated to the lid 31 and the fixing member 32, the compression side valve 11 and the fixed member is fixed to the valve casing 4 by screwing into the valve casing 4 of the lid 31 However, a bag-like nut can be screwed onto the outer periphery of the opening end of the valve case 4 so that the lid 31 and these assembled members can be clamped and fixed between the valve case 4 and the bag-like nut. If the lid 31 and each assembled member can be removed from the opening side of the hollow portion 4a of the valve case 4, they may be fixed by other fixing methods.

  Next, the operation of the vehicle shock absorber D configured as described above will be described. First, the case where the piston 3 moves upward in FIG. 1 and the vehicle shock absorber D extends will be described. The liquid in the expansion side working chamber R1, which is compressed by the upward movement of the piston 3 during this extension operation, pushes open the expansion side valve 12 and moves to the pressure side working chamber R2. Therefore, when the vehicle shock absorber D is extended, the expansion side valve 12 is opened to give resistance to the flow of the liquid, so that the expansion side valve 12 generates an expansion side damping force. In this case, the vehicle shock absorber D is set to a double rod type, the expansion side valve 12 is opened, the expansion side working chamber R1 and the pressure side working chamber R2 are communicated, and decreases in the expansion side working chamber R1. Since the volume of the pressure side working chamber R2 increases in accordance with the volume, there is no liquid in and out of the liquid chamber L and the cylinder 1, but the vehicle shock absorber D is set to a single rod type, that is, the piston rod 17 When the lower portion 17b is discarded, the compensation check valve 34 is opened and the insufficient liquid is supplied from the liquid chamber L to the pressure side working chamber R2.

  Next, the case where the piston 3 moves downward in FIG. 1 and the vehicle shock absorber D contracts will be described. During the contraction operation, the liquid in the pressure side working chamber R1 compressed by the lowering of the piston 3 pushes the pressure side valve 11 open and moves to the liquid chamber L. Therefore, when the vehicular shock absorber D is contracted, the pressure side valve 11 is opened to provide resistance to the flow of the liquid, so that the pressure side valve 11 generates a pressure side damping force. In addition, liquid is supplied from the liquid chamber L to the expansion side working chamber R1 to be expanded by opening the suction check valve 13.

  Although the vehicle shock absorber D operates as described above, the vehicle shock absorber D includes the pressure chamber P that pressurizes the liquid chamber L and the liquid chamber L. The liquid column rigidity in the working chamber R1 and the pressure side working chamber R2 can be increased.

  In the vehicle shock absorber D, the expansion side working chamber R1 compressed during the expansion stroke is not communicated with the liquid chamber L through a path without any resistance, and is compressed during the contraction stroke. Since the pressure side working chamber R2 communicated with the liquid chamber L through the pressure side valve 8 is not communicated with the liquid chamber L through a path without any resistance, the liquid chamber L is not in the expansion and contraction strokes. It does not behave as a chamber on the compression side and the liquid column rigidity of the liquid is not lowered.

  Thus, according to the vehicular shock absorber D, not only can the liquid column rigidity of the extension side working chamber R1 and the pressure side working chamber R2 be increased, but also the liquid chamber L behaves as a compression side chamber during the expansion / contraction stroke. Therefore, even if the piston speed during expansion / contraction is low, the damping force generation responsiveness can be improved and the riding comfort in the vehicle can also be improved. Therefore, in the vehicle shock absorber D, changes in the posture of the vehicle body such as when the vehicle is turning, braking, or accelerating can be firmly suppressed from the initial posture change.

  Further, in the vehicle shock absorber D, a partition wall 5 having an attenuation passage 8 is provided in a valve case 4 provided on the side of the outer tube 2, and the attenuation passage 8 is opened and closed to open the auxiliary working chamber 6. Since the pressure side valve 11 that allows only the flow of the liquid toward the sub liquid chamber 7 and provides resistance to the flow of the liquid is accommodated in the valve case 4, the damping force generation responsiveness is enhanced and the outer circumference of the outer tube 2 is increased. The suspension spring receiver 14 for supporting the suspension spring S can be provided, and since the compression side valve 11 is installed outside the outer tube 2, the cylinder length is also shortened, so that mountability to the vehicle is not sacrificed. .

  In the vehicle shock absorber D, if the extension side working chamber R1 is the starting point, the liquid flow circulates from the extension side working chamber R1 to the extension side working chamber R1 via the pressure side working chamber R2 and the liquid chamber L. Since it becomes a flow of traffic, the flow of the liquid does not reverse when the expansion and contraction of the vehicle shock absorber D is switched. Thus, since the reversal of the flow of the liquid does not occur, it is possible to suppress a delay in the generation of the damping force when the vehicle shock absorber D is switched between expansion and contraction. In the vehicle shock absorber D, the compensation passage 33 and the compensation check valve 34 can be eliminated. However, when these are provided, when the pressure decreases in the pressure side working chamber R2, The liquid can be quickly supplied from the liquid chamber L to the pressure side working chamber R2, and the pressure in the pressure side working chamber R2 can be compensated to prevent vacuum.

  Further, since the vehicle shock absorber D in the present embodiment is of a double rod type, there is no liquid in / out of the liquid chamber L and the cylinder 1 during the expansion / contraction operation, so the pressure in the liquid chamber L There is no fluctuation, which can contribute to further improvement in response to generation of damping force.

  In the above description, the damping valve is the pressure side valve 11. However, if the extension side working chamber R1 communicates with the sub working chamber 6, the damping valve is attenuated when the vehicle shock absorber D is extended. In this case, for example, a leaf valve that functions as a pressure-side valve for the piston 3 by using the expansion-side passage 9 as a pressure-side passage by eliminating the extension-side valve 12 and the like. The valve may be provided. Further, in this case, the suction passage 10 is abolished, and a passage that connects the liquid chamber L to the pressure side working chamber R2 is provided, and liquid is supplied to the pressure side working chamber R2 through the passage when the vehicle shock absorber D is extended. It is good to supply, and it is possible to make the extension side working chamber R1 and the sub working chamber 6 communicate with each other by utilizing an annular gap between the cylinder 1 and the outer tube 2.

  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.

  The hydraulic shock absorber for a vehicle according to the present invention can be used for a vibration damping application of a vehicle.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Outer tube 3 Piston 4 Valve case 4a Hollow part 5 Partition 6 Sub working chamber 7 Sub liquid chamber 8 Attenuation passage 9 Extension side passage 10 Suction passage 11 Pressure side valve 12 Extension side valve 13 Suction check valve 14 Suspension spring receptacle 31 Lid 31d Fitting portion 32 Fixing member L Liquid chamber P Pressurizing means R1 Extension side working chamber R2 Pressure side working chamber

Claims (4)

A cylinder, a piston that is inserted slidably into the cylinder, the extension side working chamber and the compression side working chamber partitioned by the piston within the cylinder, a liquid chamber, provided on the side of the cylinder a valve case having a hollow portion which opens outwardly, and barrier ribs partitioning is housed in the hollow portion and the secondary working chamber and the auxiliary liquid chamber, from one of the extension side working chamber and the pressure side working chamber A communication path that leads to the sub working chamber; a liquid chamber passage that leads from the liquid chamber to the sub liquid chamber; a damping passage that is provided in the partition and communicates the sub working chamber and the sub liquid chamber; and the valve It is accommodated in the case in a vehicle shock absorber comprising a damping valve that provides resistance to the flow of the liquid along with permitting only flow of liquid toward the auxiliary liquid chamber from the auxiliary hydraulic chamber to open and close the damping passage ,
A lid for closing the opening of the hollow part;
And a fixing member for fixing the partition wall to said cap,
The volume occupied in the valve case by the lid, the fixing member, the partition wall, the damping valve, and the fixed member fixed to the fixing member accommodated in the hollow portion is the communication path and the liquid chamber path. set to be smaller than the hollow interior volume of the opening end side of the edge of the open end at the outlet end is positioned on the opening end side of the hollow portion of the valve case of the end outlet to the hollow portion A vehicle shock absorber. The lid is provided with a flange-shaped fitting portion at the lower end, only the outer periphery of the fitting portion is fitted to the inner periphery of the lower end opening of the valve case, the upper side of the fitting portion and the valve case 2. The vehicle shock absorber according to claim 1, wherein an annular gap is formed between the two. The communication path communicates the pressure side working chamber to the sub working chamber,
A pressurizing means for pressurizing the liquid chamber;
An extension side damping passage communicating the extension side working chamber and the pressure side working chamber;
A suction passage communicating the extension side working chamber and the liquid chamber;
An extension side valve that opens and closes the extension side damping passage and allows only the flow of liquid from the extension side working chamber to the pressure side working chamber and provides resistance to the flow of the liquid;
The vehicle buffer according to claim 1, further comprising a suction check valve that is provided in the middle of the suction passage and allows only a flow of liquid from the liquid chamber toward the extension side working chamber. vessel. An outer tube covering the cylinder,
The liquid chamber is provided in the outer tube below the extension side working chamber and the pressure side working chamber,
The suction passage is formed by a gap provided between the cylinder and the outer tube,
A suspension spring support provided above the valve case of the outer tube,
Towards the opening of the hollow portion downward, claim 3, characterized in that the outlet end to said hollow portion of said connecting path is arranged downward from the lower end of the lower end and the compression side working chamber of the extension side working chamber The vehicle shock absorber described in 1.

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