JP5698561B2 - Shock absorber - Google Patents

Description

  The present invention relates to a shock absorber.

  In this type of shock absorber, generally, a cylinder, a piston that is slidably inserted into the cylinder and divides the cylinder into an output shaft side chamber and a piston side chamber, and is movably inserted into the cylinder. And a piston rod whose one end is connected to the piston (see, for example, Patent Document 1).

  The shock absorber is used to dampen the vibration of the vibration control target. For example, when the shock absorber is incorporated in the suspension of the vehicle, the shock absorber is interposed between the vehicle body and the wheel that is the vibration control target. The vibration is suppressed.

  By the way, in recent years, a lot of electronic devices are mounted on a vehicle in addition to devices necessary for running such as a suspension and an engine. In a hybrid vehicle, a motor is mounted in addition to the engine. As described above, various various devices are mounted on the vehicle, and it is desired to secure a large space in the vehicle interior. An increase in the amount of equipment will reduce the space in the passenger compartment, so that it is desired to reduce the size of each device, and it is also desirable to reduce the size of the shock absorber as well.

  As a small shock absorber, for example, a container, a guide shaft that is movably inserted into the container, a cylindrical mounting rubber that is fixed to the opening and the guide shaft of the container, and an end of the guide shaft are connected. In this shock absorber, when the damper plate moves in the axial direction in the container, the damping liquid in the container suppresses the movement of the damper plate. Demonstrates a damping force (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-267067 Japanese Patent Laid-Open No. 2003-113889

  In the shock absorber disclosed in Japanese Patent Laid-Open No. 2003-113889, as represented by Japanese Patent Laid-Open No. 10-267067, the size of the shock absorber is smaller than that of a conventional general shock absorber.

  However, the shock absorber disclosed in Japanese Patent Application Laid-Open No. 2003-113889 has no problem when used between a cab such as a truck and the vehicle body, but is interposed between the vehicle body and the wheel of the vehicle. There is a problem to use as a shock absorber.

  This is because the guide shaft is elastically supported by the mound rubber, so that when the lateral vibration is input, the guide shaft is inclined with respect to the container and formed at the inner periphery of the container and the outer periphery of the damper plate. The channel area changes. Then, there is a possibility that the damping force generated in the damper plate varies, the damping force is not stable, and the riding comfort of the vehicle cannot be maintained satisfactorily.

  Therefore, the present invention has been developed to improve the above-described problems, and the object of the present invention is to be small in size and to maintain stable riding comfort in a vehicle by exhibiting a stable damping force. It is to provide a shock absorber that can.

In order to solve the above-described problems, the problem-solving means of the present invention includes a shock absorber body provided with pressure chambers that are opened from both ends at both ends and filled with liquid, and can be moved freely into the pressure chambers. an output shaft inserted, the elastic member in an annular to permit axial movement of at least the output shaft and fixed to the outer periphery of the output shaft with and closes the opening of each pressure chamber to seal the pressure chamber A sealing body comprising: a damping passage that communicates with each of the pressure chambers and that provides resistance to the flow of the liquid that exchanges between the pressure chambers; a bracket that fixes the shock absorber body to an installation location; And a compensation chamber having a liquid chamber and an air chamber, wherein the liquid chamber communicates with at least one of the pressure chambers .

According to the shock absorber of the present invention, the length of the shock absorber body only needs to be long enough to ensure the stroke of the output shaft, and no piston or base valve is required. The overall length can be shortened to reduce the size. That is, according to the shock absorber of the present invention, it is small in size and can exhibit a stable damping force and maintain a good riding comfort in the vehicle. Further, since the output shaft is fixed to the elastic sealing body and elastically supported, it does not have a sliding part, and an uncontrollable frictional force is added to the damping force, thereby impairing the riding comfort in the vehicle. There is no problem. Furthermore, by providing the compensation chamber inside the bracket, the shock absorber body can be further shortened in the longitudinal direction and reduced in diameter in the radial direction, and the mountability of the shock absorber to the vehicle can be improved. .

It is a longitudinal cross-sectional view of the shock absorber in one embodiment. It is a figure which shows the state which interposed the buffer in one Embodiment between the vehicle body and the wheel of a vehicle. It is a longitudinal cross-sectional view of the buffer in other embodiment. It is a longitudinal cross-sectional view of the shock absorber in another embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, a shock absorber D according to an embodiment includes a shock absorber body 1 having pressure chambers R1 and R2 that are opened from both ends at both ends and filled with liquid, and each pressure. The output shafts 2 and 3 that are movably inserted into the chambers R1 and R2, respectively, and the openings of the pressure chambers R1 and R2 are closed to seal the pressure chambers R1 and R2, and the outer periphery of the output shafts 2 and 3 The annular sealed bodies 4 and 5 that allow the output shafts 2 and 3 to move in the axial direction and the pressure chambers R1 and R2 are communicated with each other, and the flow of the liquid exchanges between the pressure chambers R1 and R2. Attenuating passages 6 and 7 for providing resistance are provided.

  Hereinafter, each part of the shock absorber D will be described in detail. The shock absorber body 1 includes a central block 1a and cylindrical portions 1b and 1c provided on both sides of the central block 1a. The pressure chambers R1 and 1c are disposed in the cylindrical portions 1b and 1c at both ends. R2 is formed.

  The lower end in FIG. 1 of the cylindrical portion 1b and the upper end in FIG. 1 of the cylindrical portion 1c are closed by the central block 1a, and the upper end in FIG. 1 of the cylindrical portion 1b and the lower end in FIG. It is an opening.

  Next, the cylinder parts 1b and 1c, the output shafts 2 and 3, and the sealed bodies 4 and 5 will be described in detail. The cylinder part 1b and the cylinder part 1c, the output shaft 2 and the output shaft 3, the sealed body 4 and the sealed body 5 are described. Since the structure is the same, for the sake of simplicity of description, parentheses are attached to the reference numerals in the description of members having the same structure to avoid duplication of description.

  In this case, the output shaft 2 (3) has a rod shape, but the shape is not limited as long as the output shaft 2 (3) can be connected to a vibration-suppressed object when mounted on a vehicle.

  An output shaft 2 (3) is movably inserted into the cylindrical portion 1b (1c), and the output shaft 2 (3) has an annular shape whose outer periphery is fixed to the opening of the cylindrical portion 1b (1c). It is hold | maintained by the inner periphery of the sealing body 4 (5). More specifically, the inner periphery of the sealing body 4 (5) is firmly fixed to the outer periphery of the output shaft 2 (3) by welding or adhesion, and the outer periphery is the inner part of the cylindrical portion 1b (1c). It is firmly fixed around the periphery by welding or bonding. In addition, although not shown in figure, the holding member by which the outer periphery of the sealing body 4 (5) was fixed to the opening end of the cylinder part 1b (1c) is provided, and the said holding member is fixed to the cylinder part 1b (1c). The cylindrical portion 1b (1c) and the sealing body 4 (5) may be integrated.

  The sealing body 4 (5) may be, for example, an elastic body formed of rubber, synthetic rubber, resin or synthetic resin, or a combination thereof, or a diaphragm or bellows, and the output shaft 2 (3) It is only necessary to allow the output shaft 2 (3) to move in the vertical direction in FIG. 1 with respect to the cylinder portion 1b (1c) while sealing between the cylinder portion 1b (1c).

  As described above, the output shaft 2 (3) is supported by the sealing body 4 (5) so as to be movable in the axial direction. It is possible to make a stroke in the vertical direction in FIG. Further, in this example, the sealing body 4 (5) is an elastic body such as rubber, and can be bent in the radial direction, so that the output shaft 2 (3) is not shown in FIG. It can be moved slightly in the horizontal direction in 1 and can swing. In order to restrict the movement of the output shaft 2 (3) in the lateral direction of the sealing body 4 (5) and to provide directivity in the bending direction, a metal core is provided in the sealing body 4 (5). May be. The cored bar can be provided by insert molding when molding the sealed body 4 (5).

  And by installing the sealing body 4 (5) between the opening of the cylinder 1b (1c) and the output shaft 2 (3), the opening of the cylinder 1b (1c) is closed, and the pressure Chamber R1 (R2) is sealed.

  These pressure chambers R1 and R2 are filled with water, aqueous solution, oil or other liquid. The liquid may be a liquid that does not erode or corrode the shock absorber body 1, the output shafts 2 and 3, and the sealing bodies 4 and 5.

  The central block 1a is provided with damping passages 6 and 7 for communicating the pressure chamber R1 and the pressure chamber R2. The damping passage 6 includes a passage 6a that connects the pressure chamber R1 and the pressure chamber R2, a check valve 6b that allows only a flow from the pressure chamber R1 to the pressure chamber R2, and an attenuation that provides resistance to the flow of liquid that passes through the damping passage 6. The check valve 6b is set as a one-way passage that allows only the flow of liquid from the pressure chamber R1 to the pressure chamber R2, and resists the passing liquid by the damping valve 6c. Is supposed to give. That is, the attenuation passage 6 corresponds to the one-side attenuation passage. The damping passage 7 is resistant to the flow of the liquid passing therethrough, the passage 7a communicating the pressure chamber R2 and the pressure chamber R1, the check valve 7b allowing only the flow from the pressure chamber R2 to the pressure chamber R1. The check valve 7b is set as a one-way passage that allows only the flow of the liquid from the pressure chamber R2 to the pressure chamber R1, and the damping valve 7c for the liquid that passes through the check valve 7c. In order to give resistance. That is, the attenuation passage 7 corresponds to the other-side attenuation passage.

  In the case of this embodiment, the compensation passage 8 is connected between the check valve 6b and the damping valve 6c in the passage 6a and between the check valve 7b and the damping valve 7c in the passage 7a. It communicates with a compensation chamber R formed inside the central block 1a.

  The compensation chamber R is formed by a hollow portion formed in the central block 1a, and an accumulator 9 is accommodated in the hollow portion. This accumulator 9 is an elastic bag and is filled with gas to form an air chamber G. The accumulator 9 defines a liquid chamber L that communicates with the air chamber G and the compensation passage 8 in the compensation chamber R. Yes. In order to form the air chamber G and the liquid chamber L in the compensation chamber R, in addition to the above, for example, a free piston is slidably inserted into the hollow portion, and the air chamber G The liquid chamber L may be partitioned. Moreover, when using a free piston, you may make it pressurize with the spring from the air chamber G side and pressurize the liquid chamber L, and it is also possible to open | release the air chamber G to air | atmosphere in that case.

  The shock absorber D configured in this way, for example, as shown in FIG. 2, connects the shock absorber body 1 to the vehicle body B of the vehicle, and moves the wheels W in the vertical direction in FIG. By connecting the output shaft 2 and the output shaft 3 to the upper arm 10 and the lower arm 11 that can be supported, respectively, the vehicle can be interposed between the vehicle body B and the wheels W that are the vibration-suppressed objects. Yes. The shock absorber body 1 may be connected to one or both of the upper arm 10 and the lower arm 11 and the output shafts 2 and 3 may be connected to the vehicle body B.

  More specifically, an eye-shaped bracket 2a is provided at the tip of the output shaft 2 protruding outside the pressure chamber, and the eye-shaped bracket 2a can be pin-coupled to the upper arm 10, and Similarly, an eye-type bracket 3 a is also provided at the tip of the output shaft 3 protruding outside the pressure chamber, and this eye-type bracket 3 a can be pin-coupled to the lower arm 11.

  Therefore, when the wheel W moves upward in FIG. 2 with respect to the vehicle body B and the upper arm 10 and the lower arm 11 rotate counterclockwise in the drawing around the connecting portion of the vehicle body B, the rotation causes the output shaft 2 to move. The buffer body 1 is pulled upward in FIG. 2, and the output shaft 3 is pushed upward in FIG. 2 with respect to the buffer body 1. On the contrary, when the wheel W moves downward in FIG. 2 with respect to the vehicle body B and the upper arm 10 and the lower arm 11 rotate clockwise in the drawing around the connecting portion of the vehicle body B, the rotation causes the output shaft 2 to move. The shock absorber body 1 is pushed downward in FIG. 2, and the output shaft 3 is pulled downward in FIG. 2 with respect to the shock absorber body 1. The output shafts 2 and 3 are forced to move so that the axis of the shock absorber body 1 is inclined with respect to the shock absorber body 1 by the rotation of the upper arm 10 and the lower arm 11. The movement is allowed, and the cylindrical portions 1b and 1c of the shock absorber main body 1 are not overloaded.

  As described above, the output shaft 2 and the output shaft 3 are moved in the vertical direction almost synchronously by the upper arm 10 and the lower arm 11. When the output shaft 2 moves upward in FIG. 1 with respect to the shock absorber body 1 to expand the pressure chamber R1, the output shaft 3 also moves upward in FIG. 1 to reduce the volume of the pressure chamber R2, The volume of the expansion of the pressure chamber R1 is substantially equal to the volume of the reduction of the pressure chamber R2. When the output shafts 2 and 3 are moved downward in FIG. 1, the pressure chamber R1 is reduced and the pressure chamber R2 is enlarged. In this case as well, the reduced volume of the pressure chamber R1 and the enlarged portion of the pressure chamber R2 are expanded. The volume is almost equal. Even if the change volume of the pressure chamber R1 and the pressure chamber R2 due to the vertical movement of the output shafts 2 and 3 with respect to the shock absorber main body 1 is caused by the movement of the output shafts 2 and 3 in the tilt direction, the compensation chamber R has the volume. The difference liquid is compensated by being absorbed in the liquid chamber L or discharged into the pressure chambers R1 and R2 by expanding or contracting the gas chamber G. Further, even when the volume of the liquid changes due to a temperature change, the compensation chamber R compensates the volume change by absorbing or discharging the liquid into the pressure chambers R1 and R2 by expanding or reducing the gas chamber G. To do. Further, the compensation chamber R pressurizes the liquid filled in the pressure chambers R1 and R2 with the pressure of the air chamber G, and suppresses the influence of the reduction in the rigidity of the liquid due to the gas dissolved in the liquid, thereby generating a damping force. Improve responsiveness.

  As the damping valves 6c and 7c, variable damping valves such as rotary valves and solenoid valves as well as damping valves such as orifices, chokes, leaf valves and poppet valves can be used. In the case of having a function as a stop valve, the check valves 6b and 7b can be eliminated. In this case, the compensation chamber R communicates the liquid chamber L with one of the attenuation passage 6 and the attenuation passage 7, or separates the liquid chamber L from one or both of the pressure chambers R1 and R2 separately from the attenuation passages 6 and 7. Should be communicated. When the liquid is a magnetorheological fluid, a coil or a magnet for applying a magnetic field to the magnetorheological fluid may be provided in the damping passages 6 and 7 instead of the damping valves 6c and 7c. When a fluid is used, electrodes for applying an electric field to the electrorheological fluid may be provided in the damping passages 6 and 7 instead of the damping valves 6c and 7c.

  Now, in the shock absorber D configured as described above, as described above, the output shafts 2 and 3 are interposed between the vehicle body B and the wheels W so that the output shafts 2 and 3 are located with respect to the shock absorber body 1. 1 moves up and down in FIG.

  When the output shafts 2 and 3 move upward in FIG. 1 with respect to the shock absorber main body 1, the volume of the pressure chamber R1 is increased and the volume of the pressure chamber R2 is decreased, so that the pressure chamber R2 is moved to the pressure chamber R1. The liquid tries to move. In this case, since the check valve 6b is closed and cannot pass, the liquid moves from the pressure chamber R2 to the pressure chamber R1 by opening the check valve 7b in the attenuation passage 7. Since the damping valve 7c provides resistance to this liquid flow, the pressure in the pressure chamber R2 rises, and the shock absorber D is a damping force obtained by multiplying the inner diameter cross-sectional area of the cylindrical portion 1c by the pressure change in the pressure chamber R2. To prevent the output shaft 3 from entering the cylindrical portion 1c. That is, the shock absorber D exhibits a damping force that suppresses the movement of the wheel W relative to the vehicle body B in the upward direction in FIG. On the contrary, when the output shafts 2 and 3 move downward in FIG. 1 with respect to the shock absorber main body 1, the volume of the pressure chamber R2 is enlarged and the volume of the pressure chamber R1 is decreased. The liquid tries to move to. In this case, since the check valve 7b is closed and cannot pass, the liquid moves from the pressure chamber R1 to the pressure chamber R2 by opening the check valve 6b in the attenuation passage 6. Since the damping valve 6c provides resistance to the liquid flow, the pressure in the pressure chamber R1 rises, and the shock absorber D is a damping force obtained by multiplying the inner diameter cross-sectional area of the cylindrical portion 1b by the pressure change in the pressure chamber R1. To prevent the output shaft 2 from entering the cylindrical portion 1b. That is, the shock absorber D exhibits a damping force that suppresses the movement of the wheel W relative to the vehicle body B in the downward direction in FIG.

  In this way, the shock absorber D exhibits a damping force, but the damping force is generated in the damping passages 6 and 7 that provide resistance to the flow of the liquid that exchanges the pressure chambers R1 and R2, and the output shaft 2, Even if 3 is tilted or decentered with respect to the shock absorber body 1, the flow passage area of the damping passages 6 and 7 does not change and the passage flow rate is stable, so that a stable damping force can be exerted. Is possible. Therefore, the shock absorber D can exhibit a stable damping force and maintain a good riding comfort in the vehicle.

  Further, when the output shafts 2 and 3 move upward in FIG. 1 with respect to the shock absorber main body 1, the shock absorber D exhibits a damping force by the damping valve 7 c in the damping passage 7, and the output shafts 2 and 3. When 3 moves downward in FIG. 1 with respect to the shock absorber body 1, the damping valve 6c in the damping passage 6 exhibits a damping force, so that the resistance given to the liquid flow by the damping valves 6c and 7c is different. If so, the characteristics of the damping force generated when the output shafts 2 and 3 move upward relative to the shock absorber main body 1 and the damping force generated when the output shafts 2 and 3 move downward relative to the shock absorber main body 1. The characteristics of can be different. In the shock absorber D, the lengths of the cylindrical portions 1b and 1c need only be long enough to secure the stroke of the output shafts 2 and 3, and a piston and a base valve are not required. Compared to the above, the overall length can be shortened and the size can be reduced.

  Therefore, according to the shock absorber D of the present invention, it is small in size, can exhibit a stable damping force, and can maintain a good riding comfort in the vehicle.

  Moreover, since the damping force is exhibited by boosting the pressure chambers R1 and R2 with the inner diameter area of the cylindrical portions 1b and 1c as the pressure receiving area, the damper or the single output shaft provided with the conventional damper plate is also exhibited. Compared to the type shock absorber, it is structurally advantageous that a high damping force is easily exerted in both the vertical directions of the output shafts 2 and 3.

  Further, the output shafts 2 and 3 are elastically supported by the sealing body 4 and integrated with the shock absorber main body 1, and sliding parts such as a piston rod and a rod guide, a cylinder and a piston, which are found in a general shock absorber. Therefore, in this shock absorber D, a frictional force that cannot be controlled by the damping force is added, and the riding comfort in the vehicle is not impaired. In the shock absorber D, when the air chamber G is partitioned in the compensation chamber R, the accumulator 9 is used so that the sliding portion is eliminated also in the compensation chamber R and no friction force is generated. Therefore, the influence of the frictional force in the compensation chamber R on the damping force is also eliminated.

  In addition, you may make it provide compensation chamber R3, R4 in the output shafts 2 and 3 like the buffer D1 of other embodiment shown in FIG. The shock absorber D1 of the other embodiment is different from the shock absorber D only in that the compensation chambers R3 and R4 are provided in the output shafts 2 and 3, and the same members are denoted by the same reference numerals because the description is duplicated. Detailed description will be omitted.

  In the shock absorber D1 of another embodiment, the compensation chamber R3 is provided in the output shaft 2, and the compensation chamber R4 is provided in the output shaft 3. A free piston 13 is slidably inserted in the compensation chamber R3, and is divided into a liquid chamber L1 and a gas chamber G1 by the free piston 13. The liquid chamber L1 communicates with the pressure chamber R1 through a compensation passage 14 provided in the output shaft 2. A free piston 15 is slidably inserted in the compensation chamber R4, and is divided into a liquid chamber L2 and a gas chamber G2 by the free piston 15. The liquid chamber L2 communicates with the pressure chamber R2 through a compensation passage 16 provided in the output shaft 3.

  Even in the shock absorber D1 of this other embodiment, the output shafts 2 and 3 move in the vertical direction to boost the pressure in the pressure chamber R1 or the pressure chamber R2, thereby exhibiting a damping force. Therefore, the same operation and effect as the shock absorber D can be obtained. Further, in the buffer D1 of the other embodiment, since the compensation chambers R3 and R4 are provided in the output shafts 2 and 3, compared with the buffer D in which the compensation chamber R is provided in the central block 1a. Thus, it becomes lighter and smaller. Note that only one of the compensation chambers R3 and R4 may be provided.

  Furthermore, the shock absorber D2 in another embodiment shown in FIG. 4 holds the shock absorber main body 1 and mounts the shock absorber main body 1 to the vehicle body B instead of providing the compensation chamber R in the central block 1a of the shock absorber main body 1. A bracket 17 for fixing to the bracket 17 is provided, and the compensation chamber R5 is provided in the bracket 17.

  The bracket 17 includes a fixing portion 17a that is fixed to the vehicle body B, a holding portion 17b that holds the shock absorber main body 1, and an arm 17c that connects the fixing portion 17a and the holding portion 17b.

  A compensation chamber R5 is provided inside the fixed portion 17a. An accumulator 18 is accommodated in the compensation chamber R5, and the internal air chamber G3 and the liquid chamber L3 are partitioned by the accumulator 18. Further, check valves 6b and 7b and damping valves 6c and 7c for the damping passages 6 and 7 are also provided in the fixed portion 17a, and the liquid chamber L3 is communicated with the damping passages 6 and 7 through the compensation passage 19. ing.

  Thus, the shock absorber D2 is provided with the check valve 6b, 7b, the damping valve 6c, 7c and the compensation chamber R5 provided in the shock absorber main body 1 by the shock absorber D inside the bracket 17, so that the shock absorber main body is provided. 1 can be further shortened in the longitudinal direction and reduced in diameter in the radial direction, and the mountability of the shock absorber D2 on the vehicle can be improved. Even when only the compensation chamber R5 is provided in the bracket 17, it is possible to further shorten the longitudinal direction of the shock absorber body 1 and reduce the diameter in the radial direction as compared with the shock absorber D.

  In addition, in the shock absorbers D, D1, and D2 of the above-described embodiments, an attenuation passage that allows liquid to pass in both directions through the pressure chamber R1 and the pressure chamber R2 is provided instead of the attenuation passages 6 and 7. May be. It is also possible to make the inner diameters of the cylindrical portion 1b and the cylindrical portion 1c different. In this case, the buffering device always exerts an urging force in a direction in which the output shaft having the larger inner diameter protrudes from the buffer body. It is possible.

  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.

DESCRIPTION OF SYMBOLS 1 Buffer body 2, 3 Output shaft 4, 5 Sealing body 6, 7 Damping passage 6b, 7b Check valve 6c, 7c Damping valve 16 Bracket D, D1, D2 Buffer G, G1, G2, G3 Air chamber L, L1, L2, L3 Liquid chamber R, R3, R4, R5 Compensation chamber R1, R2 Pressure chamber

Claims (3)

A shock absorber body provided with pressure chambers that are open from both ends at both ends and filled with liquid;
An output shaft movably inserted into each of the pressure chambers;
A sealing body made of an elastic body at annular to permit axial movement of at least the output shaft and fixed to the outer periphery of the output shaft with and closes the opening of each pressure chamber to seal the pressure chamber,
An attenuation passage that provides resistance to the flow of the liquid that communicates the pressure chambers and exchanges the pressure chambers ;
A bracket for fixing the shock absorber body to the installation location;
A shock absorber, comprising: a compensation chamber provided in the bracket and having a liquid chamber and an air chamber, and the liquid chamber communicates with at least one of the pressure chambers . The damping passage allows only the flow from one side of the pressure chamber to the other and gives resistance to the flow, and allows only the flow from the other side of the pressure chamber to the one side. The shock absorber according to claim 1, further comprising an attenuation passage on the other side that provides resistance to the shock absorber. And a damping passage of the damping passage and the other side of the one side are both damping valve and the check valve, as claimed in claim 2, characterized in that a and damping valve and the check valve in the bracket Shock absorber.

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