JP2012211627A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a change in the configuration of a damping portion, without needing disassembling work for taking out a piston body from an inner cylinder.SOLUTION: A shock absorber has a shock absorber body consisting of an outer cylinder 1, an inner cylinder 2 inserted into the outer cylinder 1 to be movable in and out, a rod body 3 vertically provided in the shaft core portion of the outer cylinder 1, and a piston body 4 provided in the inner cylinder 2, being connected to the rod body 3, and has a damping portion V which performs damping action when the piston body 4 moves up and down in the inside of the inner cylinder 2, wherein the inner cylinder 2 has an auxiliary cylinder 6 arranged coaxially in the inner cylinder 2, an annular passage way L is compartmentalized formed between the auxiliary cylinder 6 and the inner cylinder 2, by housing slidably the piston body 4 in the auxiliary cylinder 6, a rod side chamber R1 in which the rod body 3 is inserted and a piston side chamber R2 in which the rod body 3 is not inserted are compartmentalized formed in the auxiliary cylinder 6, the rod side chamber R1 and the piston side chamber R2 are made to be connectable through a connecting passage way L1 provided outside of the annular passage way L and the inner cylinder 2 which connects this annular passage way and the piston side chamber, and at the same time, the damping portion V is provided in the connecting passage way L1.

Description

  The present invention relates to a shock absorber, and more particularly, to an improvement of a shock absorber suitable for mounting on a vehicle.

  There have been various proposals so far for shock absorbers suitable for equipment on vehicles. Among them, for example, in the proposal disclosed in Patent Document 1, the front fork serving as a shock absorber is a wheel side that is an inner cylinder. It has a piston body that is in direct sliding contact with the inner periphery of the tube.

  That is, in FIG. 7 showing the place disclosed in Patent Document 1, the front fork as a shock absorber is an inner cylinder that is a lower end side member in a vehicle body side tube that is an outer cylinder 1 that is an upper end side member. Two wheel side tubes are inserted so as to be able to enter and exit, and can be expanded and contracted.

  And in this front fork, the vehicle body side tube has the rod body 3 suspended from the shaft core portion, and the wheel side tube has the piston body 4 that slides the outer periphery on the inner periphery of the wheel side tube. The piston body 4 is connected to the tip end portion which is the lower end portion of the rod body 3.

  The piston body 4 is located above the piston body 4 in a wheel side tube that contains a working fluid typified by hydraulic oil, and is located below the piston body 4 and a rod side chamber R1 through which the rod body 3 is inserted into the shaft core. A piston side chamber R2 in which the rod body 3 is not inserted through the shaft core portion is defined.

  The piston body 4 allows the rod side chamber R1 and the piston side chamber R2 to communicate with each other, and when the working fluid reciprocates between the rod side chamber R1 and the piston side chamber R2, the expansion side damping performs a predetermined damping action. It has an attenuation part (not shown) composed of the means 4a and the compression side attenuation means 4b.

  On the other hand, in this front fork, an annular room R3 is defined between the vehicle body side tube and the wheel side tube, and this annular room R3 is formed through the communication hole 2a that opens the wheel side tube. It communicates with the rod side chamber R1 which is the inside of the wheel side tube.

  The cross-sectional area A2 of the annular chamber R3 and the cross-sectional area A1 of the rod body 3 that passes through the rod-side chamber R1 are set to satisfy A1 ≦ A2.

  As a result, the flow rate change of the working fluid in the wheel side tube when the rod body 3 enters and exits the wheel side tube is absorbed, and in particular, the piston body 4 rises in the wheel side tube and expands the piston side chamber R2. When this is done, no negative pressure phenomenon is caused in the piston side chamber R2.

  In this front fork, the upper end opening of the wheel side tube is closed by the partition member 5. At this time, the partition wall member 5 has a concave portion (not shown) formed in a bottomed cylindrical shape having a square U-shaped section inside the opening end portion of the wheel side tube and at the upper end of the concave portion. While the outer flange (not shown) is integrally connected to the upper end of the wheel side tube, the outer periphery of the outer flange is brought into sliding contact with the inner periphery of the vehicle body side tube.

  In addition, the partition member 5 allows the rod body 3 to pass through the shaft core portion of the recess, stores the working fluid with the recess as a liquid reservoir R, and places the liquid level O above the liquid level O of the working fluid. It has air chamber A as a boundary.

  Further, the partition member 5 has a check valve 5a for preventing the working fluid from passing from the rod side chamber R1 below at the bottom of the recess, and in parallel with the check valve 5a, the partition member 5 from the rod side chamber R1. It has a throttle 5b that allows the working fluid that thermally expands and bubbles to flow into the liquid reservoir R.

  Therefore, in the front fork shown in FIG. 7, when this expands and contracts, that is, when the piston body 4 moves up and down in the wheel side tube, the extension side damping means 4a and the pressure side damping means possessed by the piston body 4 are provided. The damping means 4b performs a predetermined damping action.

  And in this front fork, since the piston body 4 is directly accommodated in the wheel side tube, the piston body in the damper cylinder in the damper disposed inside the wheel side tube as in the conventional front fork. Compared with the case where it is housed, the pressure receiving area is increased, and an effective damping action can be realized.

Japanese Patent No. 4055843

  However, in the proposal disclosed in Patent Document 1 described above, that is, in the shock absorber as the front fork shown in FIG. 7, the piston body is fundamental in that the pressure receiving area is increased to enable an effective damping action. However, there is a possibility that it is pointed out that there is a minor defect in its use.

  That is, in the above-described shock absorber shown in FIG. 7, the piston body 4 which is the front fork is provided with an attenuation portion having the expansion side attenuation means 4a and the compression side attenuation means 4b.

  Therefore, even if it is desired to change the configuration of this attenuation portion, that is, the configuration of the extension side attenuation means 4a and / or the compression side attenuation means 4b, for example, the thickness and number of leaf valves constituting the attenuation means, This cannot be easily done.

  That is, in the shock absorber shown in FIG. 7, when changing the configuration of the attenuating means in the attenuating section, the upper end opening of the outer cylinder 1 is opened and the piston body 4 is taken out from the inner cylinder 2. Disassembling work is indispensable. For example, even if it is desired to change the configuration of the attenuating section suddenly during a race, there is a problem that cannot be easily dealt with.

  The present invention was devised in view of the above-described circumstances, and provides a shock absorber that does not require a disassembling work for taking out the piston body from the inner cylinder and facilitates the change of the configuration of the damping portion. For the purpose.

  In order to achieve the above-described object, the shock absorber according to the present invention includes an outer cylinder as an upper end member, an inner cylinder as a lower end member inserted into the outer cylinder so as to be able to enter and exit, and a shaft of the outer cylinder. It has a shock absorber body comprising a rod body suspended from the core and a piston body connected to the rod body and provided inside the inner cylinder, and the piston body ascends and descends inside the inner cylinder. In the shock absorber having a damping portion that sometimes performs a damping action, the inner cylinder has an auxiliary cylinder on the inner side, and an annular passage is defined between the auxiliary cylinder and the inner cylinder, and the auxiliary cylinder A cylinder slidably accommodates the piston body, and defines a rod side chamber through which the rod body is inserted into the auxiliary cylinder and a piston side chamber through which the rod body is not inserted, the rod side chamber, the piston side chamber, Are the annular passage and the annular passage and the piston. It communicates via a communication path provided outside of the inner tube that connects the chamber, and the damping portion is provided in the communication passage.

  Therefore, in the present invention, the piston body moves up and down in the auxiliary cylinder when the inner cylinder enters and exits the outer cylinder, and therefore, the rod side chamber and the piston defined by the piston body in the auxiliary cylinder. The side chamber expands and contracts.

  The inner cylinder is formed in a double cylinder structure having an auxiliary cylinder inside, and an annular passage is formed between the inner cylinder and the auxiliary cylinder. The annular passage connects the annular passage and the piston side chamber. Since it communicates with a communication path provided outside, that is, an external path provided outside the shock absorber body, the rod side chamber and the piston side chamber defined by the piston body in the inner cylinder are annular passages and external passages. It is possible to communicate via

  An attenuation portion is provided in the external passage, and the rod side chamber and the piston side chamber communicate with each other through the attenuation portion, so that the attenuation portion performs an attenuation action.

  In addition, since the attenuation part is disposed in the external passage, when changing the configuration of the attenuation part, the piston body is taken out from the auxiliary cylinder as compared with the case where the attenuation part is provided in the piston body in the auxiliary cylinder. So-called disassembling work is not required, and it becomes easy to change the configuration of the damping section, for example, to change the thickness and number of leaf valves.

  Furthermore, since the damping part is arranged in the external passage, when changing the generated damping force in the damping part, a free configuration can be selected such as a change by manual operation or a change by automatic control such as using a solenoid. Is possible.

  As a result, according to the present invention, it is possible to easily change the configuration of the attenuating portion without requiring a disassembling operation for taking out the piston body from the inner cylinder.

It is a figure which shows in principle the shock absorber by one Embodiment of this invention. It is a figure which shows the shock absorber by other Embodiment of this invention similarly to FIG. It is a figure which shows the shock absorber by other Embodiment of this invention similarly to FIG. It is a figure which shows the shock absorber by other Embodiment of this invention similarly to FIG. It is a figure which shows the shock absorber by other Embodiment of this invention similarly to FIG. It is a figure which shows the shock absorber by other Embodiment of this invention similarly to FIG. It is a figure which shows the shock absorber as a prior art example similarly to FIG.

  The present invention will be described below on the basis of the illustrated embodiment. In the illustrated embodiment, the shock absorber according to the present invention is mounted on the front wheel side of a two-wheeled vehicle (not shown) as a vehicle and is suspended at the lower end. The front fork absorbs road surface vibrations input to the front wheels (not shown).

  Although the front fork is mounted on the front wheel side of the two-wheeled vehicle, although not shown, the upper end sides of the pair of left and right front forks are integrated in advance by a bridge mechanism.

  And the lower end part of the inner cylinder 2 (refer FIG. 1) in a pair of front forks integrated by the bridge mechanism is connected to the axle (not shown) of the front wheel so as to sandwich the front wheel.

  Although not shown, the bridge mechanism includes an upper bracket connected to the upper side of the upper end of the outer cylinder 1 constituting the front fork and an under bracket connected to the lower side.

  Although not shown in the drawing, the upper bracket and the under bracket are gripped integrally by inserting the upper end portion of the outer cylinder 1 through the attachment holes of the split structure formed at both ends.

  Further, although not shown in the figure, this bridge mechanism has a single steering stem that integrally connects the upper and lower upper brackets and the under bracket at the center of both.

  The steering stem is pivotally connected to a head pipe that forms the front end of a vehicle body in a two-wheeled vehicle, and serves as a center of rotation when the handle is operated. Allows steering in the direction.

  By the way, the shock absorber according to the present invention is as shown in FIG. 1, and includes an outer cylinder 1 that is an upper end member, an inner cylinder 2 that is a lower end member that is inserted into the outer cylinder 1 so as to be able to enter and exit, and an outer cylinder. 1 has a shock absorber body (not shown) including a rod body 3 suspended from the shaft core portion 1 and a piston body 4 connected to the rod body 3 and provided inside the inner cylinder 2. .

  The shock absorber body is defined by the urging force of a suspension spring (not shown), or in place of the suspension spring or together with the suspension spring, with the liquid level O of the working fluid represented by the working oil in the shock absorber body as a boundary. The air cylinder A is energized in the extending direction in which the inner cylinder 2 protrudes from the outer cylinder 1 with the air pressure enclosed.

  Further, in this shock absorber, the inner cylinder 2 accommodates the working fluid, and the auxiliary cylinder 6 in the form of a cylinder body is erected on the shaft core portion, and the above-described working fluid is also accommodated in the auxiliary cylinder 6.

  In this shock absorber, the piston body 4 is slidably accommodated in the auxiliary cylinder 6. The piston body 4 is located above the piston body 4 in the auxiliary cylinder 6 and has a shaft core portion. The rod side chamber R1 into which the rod body 3 is inserted, and the piston side chamber R2 which is below the piston body 4 and does not allow the rod body 3 to pass through the shaft core portion.

  Further, in this shock absorber, the piston body 4 is connected to the tip portion which is the lower end portion in the figure of the rod body 3 suspended from the shaft core portion of the outer cylinder 1.

  Incidentally, as will be described in detail later, in this shock absorber, when the working fluid reciprocates between the rod side chamber R1 and the piston side chamber R2 due to the sliding of the piston body 4 in the auxiliary cylinder 6, this operation is performed. About the attenuation | damping part V which has the attenuation | damping means which accept | permits passage of a fluid and performs a predetermined | prescribed attenuation | damping action, this is arrange | positioned outside a buffer body.

  Although not shown, the shock absorber has upper and lower bearings that are spaced apart from each other between the outer cylinder 1 and the inner cylinder 2, and the outer cylinder 1 and the inner cylinder are separated by the spaced apart arrangement of the upper and lower bearings. Assures sliding with concentricity between the two.

  Further, a seal member is disposed on the inner periphery of the opening end portion which is the lower end portion in FIG. 1 of the outer cylinder 1, and will be described later which is formed by the outer cylinder 1 and the inner cylinder 2 by the arrangement of the seal member. The annular chamber R3 is sealed from the outside, and a predetermined amount of working fluid and an atmosphere of a predetermined pressure can be accommodated in the annular chamber R3.

  The outer periphery of the upper end portion of the inner cylinder 2 is in sliding contact with the inner periphery of the outer cylinder 1, but is not in sliding contact with a completely sealed state, that is, the upper and lower sides sandwiching the upper end portion of the inner cylinder 2, that is, the air The chamber A and the annular chamber R3 are in sliding contact with each other to allow communication.

  Thereby, air from the air chamber A is sucked into the annular chamber R3 when the shock absorber is contracted, but there is no problem because the air sucked when the shock absorber is extended is allowed to be released into the air chamber A. Furthermore, it is advantageous in that the configuration can be simplified.

  The air chamber A is filled with air under an arbitrary pressure, but instead of the air chamber A, a gas chamber may be used, and an inert gas may be sealed in the gas chamber under an arbitrary pressure. Further, whether it is the air chamber A or the gas chamber, the internal pressure enclosed through an air valve (not shown) disposed on the cap member that closes the upper end opening of the outer cylinder 1 may be increased or decreased. good.

  On the other hand, in this shock absorber, an annular chamber R3 is defined between the outer cylinder 1 and the inner cylinder 2, and the annular chamber R3 is formed in the inner cylinder 2 through a communication hole 2a. The inside of the inner cylinder 2 is communicated.

  In this shock absorber, the annular chamber R3 is defined between the outer cylinder 1 and the inner cylinder 2 by separating the upper and lower bearings, and the cross-sectional area A2 in the annular chamber R3, The cross-sectional area A1 in the rod body 3 is set so that A2 ≧ A1.

  Further, in the shock absorber, an annular passage L is formed inside the inner cylinder 2, that is, between the inner cylinder 2 and the auxiliary cylinder 6 described above. It communicates with the damping part V disposed outside the shock absorber main body and communicates with the rod side chamber R1 in the auxiliary cylinder 6 through the communication hole 6a opened in the auxiliary cylinder 6.

  In other words, the annular chamber R3 between the outer cylinder 1 and the inner cylinder 2 is formed in the communication hole 2a opened in the inner cylinder 2, the annular passage L between the inner cylinder 2 and the auxiliary cylinder 6, and the auxiliary cylinder 6. It communicates with the rod side chamber R1 in the auxiliary cylinder 6 through the open communication hole 6a.

  By setting the cross-sectional area A2 of the annular chamber R3 and the cross-sectional area A1 of the rod body 3 as described above (A2 ≧ A1), the inner cylinder 2 when the rod body 3 enters and exits the inner cylinder 2 Absorbs changes in the flow rate of the working fluid inside.

  By setting as described above, particularly when the piston body 4 rises in the auxiliary cylinder 6 to expand the piston side chamber R2, the piston side chamber R2 does not cause a shortage of the working fluid suction amount. Thus, no negative pressure phenomenon is caused in the piston side chamber R2.

  In this shock absorber, the upper end opening of the auxiliary cylinder 6 is closed by a partition wall member 5 formed in a thick plate shape, and the rod body 3 is passed through the axial core portion of the partition wall member 5. The outer periphery of the partition member 5 is adjacent to the inner periphery of the inner cylinder 2.

  In addition, the partition member 5 forms a liquid reservoir R above the upper end portion of the inner cylinder 2. The liquid reservoir R contains a working fluid and has an air chamber A with the working fluid and the liquid level O as a boundary.

  Further, the partition wall member 5 has a check valve 5a for blocking the passage of the working fluid from the rod side chamber R1 at the lower side at a portion closing the upper end opening of the auxiliary cylinder 6, and in parallel with the check valve 5a. And a diaphragm 5b.

  The check valve 5a prevents the working fluid from the rod side chamber R1 from flowing out into the liquid pool R. The throttle 5b is formed of, for example, a minute gap, and allows the working fluid to flow from the rod side chamber R1 to the liquid reservoir R. Therefore, the throttle 5b also allows, for example, outflow of the thermally expanded working fluid from the auxiliary cylinder 6 to the liquid reservoir R.

  Although not shown, the diaphragm 5b may be formed as a minute gap in a bush held on the inner periphery of the partition member 5 and in sliding contact with the outer periphery of the rod body 3. In this case, the diaphragm 5b is formed on the partition member 5 itself. As long as there is no need to provide, it is advantageous to simplify the configuration of the partition wall member 5.

  Incidentally, the diaphragm 5b is necessary when the cross-sectional area A2 in the annular chamber R3 is larger than the cross-sectional area A1 of the rod body 3, but the cross-sectional area A2 in the annular chamber R3 is the cross-sectional area A1 of the rod body 3. May be omitted when

  Therefore, in the drawing, the rod side chamber R1 below the partition wall member 5 communicates with the liquid reservoir R through the throttle 5b. Therefore, when the working fluid from the rod side chamber R1 mixes bubbles, The working fluid mixed with the bubbles flows into the liquid reservoir R through the throttle 5b, and the working fluid mixed with the bubbles is prevented from remaining in the rod side chamber R1.

  As a result, in the shock absorber according to the present invention, until the bubbles in the working fluid are crushed by pressurization due to the expansion and contraction operation of the shock absorber, for example, the damping portion V disposed in the external passage L1 described later is configured. In the damping means V1 and V2, there is no problem that the “damping phenomenon of sagging action” is manifested.

  Although not shown, the check valve 5a and the throttle 5b may be provided on the outer peripheral side of the partition wall member 5, that is, at a portion located at the upper end of the annular passage L. In this case, the oil sump R and the rod side chamber R1 communicate with each other via the annular passage L and the communication hole 6a.

  As described above, in the shock absorber according to the present invention, the auxiliary cylinder 6 in the cylinder body mode is erected on the inner side of the inner cylinder 2 so that the inner cylinder 2 has a so-called double cylinder structure.

  In this way, by arranging the auxiliary cylinder 6 so that the inner cylinder 2 has a double cylinder structure, that is, by forming the annular passage L between the inner cylinder 2 and the auxiliary cylinder 6, this annular passage is formed. The rod side chamber R1 in the auxiliary cylinder 6 can be communicated with the outside of the inner cylinder 2 via L.

  That is, generally speaking, in this type of shock absorber, the rod side chamber defined by the piston body is communicated to the outside of the inner cylinder inside the inner cylinder that is inserted into the outer cylinder so as to be able to enter and exit. For example, it is necessary to make a proposal disclosed in Japanese Patent Laid-Open No. 10-9327.

  However, in the case of this proposal, since the passage that connects the rod side chamber defined by the piston body and the piston side chamber in the inner cylinder is formed in the shock absorber body, the damping portion is provided on the outer periphery of the outer cylinder. As a result, the diameter of the entire shock absorber is unnecessarily increased, and there is a concern that the equipment on the vehicle may be greatly reduced.

  In addition, in the case of the proposal disclosed in the above-mentioned publication, the outer diameter of the shock absorber body is suppressed to be small in order to improve the mountability to the vehicle, and accordingly, it is accommodated in the inner cylinder. There is also a concern that the diameter of the piston body becomes smaller and the pressure receiving area of the piston body becomes smaller.

  On the other hand, in the present invention, as described above, the auxiliary cylinder 6 is disposed inside the inner cylinder 2 so that the inner cylinder 2 has a multi-cylinder structure, and between the inner cylinder 2 and the auxiliary cylinder 6. Since the annular passage L is formed and the rod side chamber in the auxiliary cylinder 6 is communicated with the outside of the inner cylinder 2 through the annular passage L, the outer diameter of the entire shock absorber is increased compared to the above proposal. This will not reduce the load on the vehicle.

  Above all, in the present invention, since the damping portion V is disposed in the external passage L1 provided outside the shock absorber main body, it is not necessary to reduce the diameter of the inner cylinder 2, and accordingly, the piston body 4 This is advantageous in that the pressure receiving area is not reduced.

  On the other hand, the damping part V in the shock absorber of the present invention is disposed in the external passage L1 provided outside the inner cylinder 2, that is, outside the shock absorber body, and is connected in series to the extension side damping means V1 and the pressure side damping means V1. Attenuating means V2 is provided.

  The extension-side damping means V1 and the compression-side damping means V2 each allow a check valve 11 that blocks the passage of the working fluid, and allows the working fluid to pass in parallel with the check valve 11. And a damping valve 12 which performs a predetermined damping action when passing.

  Therefore, in the shock absorber formed as described above, when the expansion / contraction operation is performed, that is, when the inner tube 2 enters / extracts with respect to the outer tube 1, when the expansion / contraction operation of the shock absorber body is performed, The working fluid flowing out from the rod side chamber R1 and the piston side chamber R2 defined by the piston body 4 into the auxiliary cylinder 6 standing on the inside and flowing into the opposite piston side chamber R2 and rod side chamber R1 is outside the inner cylinder 2. A predetermined damping action is performed by passing through the attenuating portion V disposed at the center.

  That is, first, during the extension operation of the shock absorber in which the inner cylinder 2 protrudes from the outer cylinder 1, the piston body 4 rises in the auxiliary cylinder 6 and the rod side chamber R1 becomes narrow.

  As a result, the working fluid in the rod side chamber R1 is formed in the communication hole 6a that opens in the auxiliary cylinder 6, the annular passage L between the auxiliary cylinder and the inner cylinder 2, and the bottom portion B that closes the lower end opening of the inner cylinder 2. Flows into the attenuating means V1 on the extension side in the attenuating portion V via the passage B1 and the external passage L1 disposed outside the inner cylinder 2.

  Then, the working fluid that has flowed into the expansion-side damping means V1 passes through the damping valve 12 and flows into the pressure-side damping means V2 in series. At this time, that is, the working fluid is a damping valve in the stretching-side damping means V1. When passing through 12, a predetermined extension side damping action is performed.

  The working fluid that has flowed into the pressure-side damping means V2 passes through the check valve 11 in the pressure-side damping means V2, flows out into the external passage L1 disposed outside the shock absorber body, and continues to the inner cylinder. 2 flows into the piston-side chamber R1 through a passage B2 formed in the bottom portion B of the two.

  At this time, when the cross-sectional area A2 in the annular chamber R3 between the outer cylinder 1 and the inner cylinder 2 is equal to the cross-sectional area A1 in the rod body 3, there is no excess or deficiency in the amount of dynamic fluid in the piston-side chamber R1.

  On the other hand, when the cross-sectional area A2 in the annular chamber R3 is larger than the cross-sectional area A1 in the rod body 3, the working fluid having a flow rate corresponding to the difference between the cross-sectional area A2 and the cross-sectional area A1 passes through the throttle 5b. It is discharged into the liquid reservoir R.

  At this time, the rod side chamber R1, the annular passage L, and the entire piston side chamber R2 are pressurized by being throttled by the throttle 5b, thereby preventing the piston side chamber R2 from becoming a negative pressure and preventing the generation of bubbles. It becomes possible.

  Even when there is a working fluid in which bubbles are mixed in the rod side chamber R1 or when there is a working fluid whose volume is increased due to thermal expansion, the working fluid is separated from the partition member 5 as described above. It flows out to the liquid reservoir R through the restriction 5b provided in

  Next, during the contraction operation of the shock absorber body in which the inner cylinder 2 is immersed in the outer cylinder 1, the piston body 4 is lowered in the auxiliary cylinder 6 standing inside the inner cylinder 2, and the piston side chamber R <b> 2 is narrowed.

  As a result, the working fluid in the piston side chamber R2 is formed in the bottom portion B of the inner cylinder 2 and the pressure side of the damping portion V via the external passage L1 disposed outside the shock absorber body to which the passage B2 communicates. It flows into the attenuation means V2.

  The working fluid that has flowed into the pressure-side damping means V2 passes through the damping valve 12 and flows into the expansion-side damping means V1, and at this time, that is, the working fluid passes through the damping valve 12 in the pressure-side damping means V2. When this occurs, a predetermined compression side damping action is performed.

  The working fluid that has flowed into the extension-side damping means V1 passes through the check valve 11 in the extension-side attenuation means V1 and flows out to the external passage L1 disposed outside the shock absorber body, and continues. It flows into rod side chamber R1 through passage B1 formed in bottom portion B of inner cylinder 2, annular passage L between inner cylinder 2 and auxiliary cylinder 6, and through hole 6a opened in auxiliary cylinder 6.

  At this time, when the cross-sectional area A2 in the annular chamber R3 between the outer cylinder 1 and the inner cylinder 2 is equal to the cross-sectional area A1 in the rod body 3, there is no excess or deficiency in the amount of working fluid in the rod-side chamber R1.

  On the other hand, when the cross-sectional area A2 in the annular chamber R3 is larger than the cross-sectional area A1 in the rod body 3, the amount of working fluid is insufficient in the annular chamber R3. The rod side chamber R1 is replenished via a check valve 5a disposed in the cylinder.

  As described above, according to the present invention, since the damping part V in the shock absorber is provided outside the shock absorber main body, the structure of the damping part V, that is, the extension side damping means V1 constituting the damping part V is provided. This can be easily performed when changing the configuration in (1) or the configuration in the compression side damping means V2 constituting the damping unit V.

  Since the damping part V is disposed outside the shock absorber body, for example, it is easy to set the damping action to be variable by manual operation or to set the damping action to be variable by using a solenoid. To do.

  By the way, regarding the above-described attenuation portion V, in the present invention, the configuration of the attenuation portion V is not specified other than having the above-described check valve 11 and attenuation valve 12, that is, arbitrarily configured. Suppose it is good.

  The front fork equipped on the motorcycle as a shock absorber may be paired on the left and right. For example, the left front fork gives priority to the damping action on the extension side, and the right front fork gives the damping action on the compression side. The attenuating unit may be configured so as to prioritize the setting.

  At this time, for example, the damping unit that prioritizes the damping action on the expansion side in the left front fork is set to make the damping action variable, or conversely, the damping that gives priority to the damping action on the compression side in the right front fork. The part may be set to make the damping action variable.

  Further, when making the damping action variable, the piston speed may be set so that the damping action is variable in an arbitrary region where the speed region starts from the low speed region and becomes the medium speed region and further the high speed region.

  2 to 6 show a shock absorber according to another embodiment of the present invention, which will be described below. In each of the drawings after FIG. 2, the configuration is shown in FIG. The same reference numerals are given to the same parts in FIG. 2 and the subsequent drawings, and detailed description thereof will be omitted unless necessary.

  Further, in each of the drawings after FIG. 2, the description about the display in which the cross-sectional area A2 in the annular chamber R3 and the cross-sectional area A1 in the rod body 3 satisfy A2 ≧ A1 is omitted.

  First, in the embodiment shown in FIG. 2, the configuration of the shock absorber body is not different from that shown in FIG. 1, and the attenuation portion V is changed.

  That is, in the damping part V of the embodiment shown in FIG. 2, the damping part V in FIG. 1 is replaced with the fixed type damping valve 12. It is assumed that the expansion side variable damping valve 12a is provided, and the compression side damping means V2 is provided with the compression side variable damping valve 12b, and each side variable damping valve 12a, Assume that a variable throttle 13 is provided in parallel with 12b and the check valve 11.

  In the damping section V shown in FIG. 2, the extension side damping means V1 and the compression side damping means V2 can realize the damping action in the high speed region of the piston speed by the variable damping valves 12a and 12b for each side. It becomes possible.

  In the variable damping valves 12a and 12b for each side, when the leaf valve is provided, the starting point position of the damping action can be changed by adjusting the cracking pressure in the leaf valve.

  In the damping section V shown in FIG. 2, the extension-side damping means V1 and the compression-side damping means V2 can realize the damping action in the medium speed region of the piston speed by the variable throttle 13.

  In the variable throttle 13, when the check valve in series with the needle valve body has a spring, by adjusting the strength of this spring, the starting point position of the damping action can be changed and thereafter The rate of change of the damping effect can be changed.

  In the embodiment shown in FIG. 3, the configuration of the attenuation portion V is not different from that shown in FIG. 2, and the configuration of the shock absorber body is changed.

  That is, in the shock absorber body shown in FIG. 3, the piston body 4 has a variable throttle 4c that allows the rod side chamber R1 and the piston side chamber R2 in the auxiliary cylinder 6 to communicate with each other. Although not shown, it is assumed that the needle valve body is provided.

  Therefore, in the embodiment shown in FIG. 3, in addition to being able to embody the same damping action as the damping action in the damping part V shown in FIG. This can be realized by the variable aperture 4c included in.

  In the variable throttle 4c, the rate of change of the damping action after the starting point can be changed by adjusting the advance / retreat position of the needle valve element.

  In the embodiment shown in FIG. 4, the configuration of the shock absorber main body is not different from that shown in FIGS. 1 and 2, and the configuration of the attenuation unit V is changed.

  That is, the attenuation part V shown in FIG. 4 is not provided separately from the expansion-side attenuation means V1 and the compression-side attenuation means V2 like the attenuation part V of the embodiment shown in FIGS. Suppose that one damping part V performs a predetermined damping action.

  4 has an extension side variable damping valve 12c, a pressure side variable damping valve 12d, and a variable throttle 13 in parallel.

  Therefore, in the embodiment shown in FIG. 4, the damping action of the expansion in the high speed region of the piston speed can be individually realized by the variable damping valves 12c and 12d for each side and the piston speed is low. It becomes possible to adjust the damping action of the tension in the region with the variable throttle 13.

  In the embodiment shown in FIG. 5, it is assumed that the shock absorber as the front fork provided on the front wheel side of the two-wheeled vehicle has different configurations on the left and right.

  That is, in the shock absorber shown in FIG. 1 to FIG. 4 described above, the shock absorber as the front fork equipped on the front wheel side of the two-wheeled vehicle has the same configuration on the left and right, that is, the pressure-sharing shared type. did.

  However, in the place shown in FIG. 5, the shock absorber as the front fork provided on the front wheel side of the two-wheeled vehicle is configured to have different attenuation portions V on the left and right, and as a result, the configuration of the attenuation portion V in the shock absorber on each side. Compared with the case where the number is one, the configuration can be simplified, and each attenuation portion V can be prevented from being bulky.

  Therefore, in the damping portion V in the so-called right leg shock absorber on the left side in FIG. 5 as shown in FIG. 5, the stretching side damping action is performed by the stretching side variable damping valve 12c. It is assumed that the pressure-side damping action is embodied by the damping valve 12.

  In the damping part V in the shock absorber for the right leg, it is assumed that the variable throttle 13 is arranged in parallel with the expansion-side variable damping valve 12c and the damping valve 12.

  On the other hand, in the damping part V in the so-called left leg shock absorber on the right side in FIG. 5, the compression side damping action is embodied by the compression side variable damping valve 12d, and the extension side damping action is realized. Is embodied by a damping valve 12.

  Even in the damping part V of the shock absorber for the left leg, the variable throttle 13 is arranged in parallel with the pressure-side variable damping valve 12d and the damping valve 12.

  Therefore, in the embodiment shown in FIG. 5, it is possible to individualize the damping action in the right and left shock absorbers, and to further improve the riding comfort in the vehicle.

  In the embodiment shown in FIG. 6, the intended place is the same as that shown in FIG. 5, but in the left and right shock absorber bodies, the piston body 4 has a variable throttle 4 c, and in each damping part V, It is assumed that the check valve 11 is connected in series with the variable throttle 13.

  At this time, the check valve 11 prevents the operation of the variable throttle 13 during the contraction operation of the shock absorber body in the damping unit V of the right leg shock absorber, and the damping valve V in the damping unit V of the left leg shock absorber. The operation of the variable throttle 13 is prevented during the extension operation of the main body.

  In the shock absorber shown in FIG. 6, in the shock absorber for the right leg, the damping portion V can control the damping action during the extension operation in the medium and high speed regions of the piston speed, and the piston body 4. It is possible to control the damping action at the time of the extension operation in the low speed region of the piston speed by the variable throttle 4c included.

  Further, in the shock absorber shown in FIG. 6, in the shock absorber for the left leg, the damping portion V can control the damping action at the time of contraction operation in the middle and high speed regions of the piston speed, and the piston body 4 It is possible to control the damping action at the time of contraction operation in the low speed region of the piston speed by the variable throttle 4c included in FIG.

  As described above, according to the present invention, since the attenuation part V in the shock absorber is disposed outside the shock absorber main body, this can be easily performed when the configuration of the attenuation part V is to be changed.

  In the present invention, since the attenuating portion V is disposed outside the shock absorber body, for example, a setting for making the damping action variable by manual operation or a setting for making the damping action variable by using a solenoid is used. Make it easy to do.

  Further, in the present invention, the configuration of the damping unit V is not specified other than having the check valve 11 and the damping valve 12, that is, it may be arbitrarily configured. When it is a front fork equipped with the above, it can be arbitrarily set such that priority is given to the damping action on the extension side on either side, and priority is given to the damping action on the compression side on the other side.

  At this time, the damping action on each side can be set to be variable based on the speed region of the piston speed.

  In the above description, the case where the shock absorber of the present invention is a front fork equipped on the front wheel side of the two-wheeled vehicle is described as an example. However, from the point of the present invention, this shock absorber is a vehicle. Of course, it may be a shock absorber provided on the rear wheel side of the two-wheeled vehicle, or may be a shock absorber provided in a four-wheeled vehicle as a vehicle.

DESCRIPTION OF SYMBOLS 1 Outer cylinder 2 Inner cylinder 2a, 6a Communication hole 3 Rod body 4 Piston body 4c, 13 Variable throttle 5 Bulkhead member 5a, 11 Check valve 5b Restriction 6 Auxiliary cylinder 12 Damping valve 12a, 12c Variable-type damping valve for expansion side 12b , 12d Pressure-side variable damping valve A Air chamber B Bottom portion L Annular passage L1 External passage O Liquid level R Liquid reservoir R1 Rod side chamber R2 Piston side chamber R3 Annular chamber V Attenuator V1 Attenuator on the expansion side V2 Attenuation on the pressure side means

Claims (6)

An outer cylinder that is an upper end member, an inner cylinder that is a lower end member that is inserted into the outer cylinder so as to be able to enter and exit, a rod body that is suspended from the shaft core portion of the outer cylinder, and a rod body that is connected to the rod body In the shock absorber having a shock absorber body comprising a piston body provided on the inner side of the inner cylinder, and having a damping portion that performs a damping action when the piston body moves up and down inside the inner cylinder,
The inner cylinder has an auxiliary cylinder inside,
An annular passage is defined between the auxiliary cylinder and the inner cylinder,
The auxiliary cylinder slidably accommodates the piston body to define a rod side chamber through which the rod body is inserted and a piston side chamber through which the rod body is not inserted,
The rod side chamber and the piston side chamber communicate with each other via the annular passage and a communication passage provided outside the inner cylinder connecting the annular passage and the piston side chamber.
A shock absorber characterized in that the attenuation portion is provided in the communication path.   A space between the outer cylinder and the inner cylinder is an annular chamber, and the annular chamber is opened through the communicating hole for opening the inner cylinder, the annular passage, and the communicating hole for opening the auxiliary cylinder. The shock absorber according to claim 1, wherein the shock absorber communicates with the rod side chamber.   The shock absorber according to claim 1, wherein an annular chamber is formed between the outer cylinder and the inner cylinder, and a cross-sectional area in the annular chamber is set larger than a cross-sectional area in the rod body.   The upper end opening of the auxiliary cylinder is closed by a partition member, and the partition member has an outer periphery adjacent to the inner periphery of the upper end portion of the inner cylinder to form a liquid reservoir above the partition member, and the liquid reservoir is the partition wall. The shock absorber according to claim 1, wherein the shock absorber is communicated with the rod side chamber or the annular passage through a check valve provided in the member and a throttle in parallel with the check valve.   2. The attenuating portion includes an extension-side damping means that allows the rod-side chamber to communicate with the piston-side chamber, and a pressure-side damping means that allows the piston-side chamber to communicate with the rod-side chamber. The shock absorber described in 1.   The attenuating section allows the rod side chamber to communicate with the piston side chamber, the expansion side damping valve, allows the piston side chamber to communicate with the rod side chamber, the pressure side damping valve, and The shock absorber according to claim 1, further comprising a variable throttle in parallel with the expansion-side damping valve.

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