JP5588387B2 - Front fork - Google Patents

Description

  The present invention relates to an improvement of a front fork in a saddle-ride vehicle such as a motorcycle.

  As is well known, a front fork in a saddle-ride vehicle such as a motorcycle (hereinafter referred to as a motorcycle) is composed of a pair of left and right shock absorber members that stand on both sides of the front wheel and suspend the front wheel, and is input to the front wheel. Suppress road surface vibration.

  Each shock absorber member includes a shock absorber body including an outer tube 1 and an inner tube 2 slidably inserted into the outer tube 1 as disclosed in, for example, Patent Document 1 and shown in FIG. The outer tube 1 is connected to the vehicle body side, and the inner tube 2 is connected to the wheel side.

  A volume compensation reservoir R is formed in the shock absorber body, and an inverted damper D1 and suspension means S1 composed of a coil spring that constantly biases the shock absorber body in the extending direction are accommodated. .

  The damper D1 stands on the inner side of the outer tube 1 via a reservoir cylinder 13 and has a cylinder 3 in which working chambers A and B filled with working fluid are formed, and an axial center portion of the inner tube 2. And a piston rod 6 that appears and disappears in the cylinder 3.

  Further, the damper D1 is held at the tip of the piston rod 6 and divides the working chambers A and B into a lower side working chamber A in FIG. 5 and a pressure side working chamber B in FIG. A base member 4 is provided which is fixed to the inner periphery of the lower end of the reservoir cylinder 13 in FIG. 5 and divides the pressure side working chamber B and the reservoir R.

  The piston 7 is provided with an extension side flow path 70 and a pressure side flow path 71 that penetrate in the axial direction and communicate with the extension side action chamber A and the pressure side action chamber B. Opening and closing is closed by a laminated leaf valve V1 stacked on the pressure side working chamber B side of the piston 7, and an outlet of the pressure side flow path 71 is opened and closed by a check valve C1 stacked on the extending side working chamber A side of the piston 7. Blocked as possible.

  Further, the base member 4 is provided with an extension side flow path 40 and a pressure side flow path 41 communicating the pressure side action chamber B and the reservoir R, and the outlet 40 of the extension side flow path is a pressure side action of the base member 4. The check valve C2 stacked on the chamber B side is closed so as to be openable and closable, and the outlet of the pressure side channel 41 is closed so as to be openable and closable by a stacked leaf valve V2 stacked on the reservoir R side of the base member 4.

  Further, the damper D1 includes a bypass path 72 in the piston that bypasses the respective flow paths 40 and 41 provided in the piston 7 and communicates the expansion side working chamber A and the pressure side working chamber B, and each flow path provided in the base member 4. A bypass passage 42 in the base member that bypasses the pressure side working chamber B and the reservoir R by bypassing 40 and 41, and a piston side adjuster 73 and a base member side adjuster 43 that adjust the opening amounts of the bypass passages 72 and 42 are provided. .

  The reservoir R is formed inside the reservoir cylinder 13 and outside the reservoir cylinder 13 and the cylinder 3, and in the reservoir cylinder 13 is a free piston that faces the base member 4 and is slidable in the axial direction. 5 and a coil spring S2 that urges the free piston 5 toward the base member 4 are provided, and a reservoir liquid chamber R1 that is filled with a working fluid is formed between the free piston 5 and the base member 4.

  In the above-described conventional front fork, the free piston 5 is biased by the coil spring S2, and the reservoir liquid chamber R1 is added to such an extent that cavitation of the pressure side working chamber B can be prevented when the front fork is extended. However, the reservoir fluid chamber R1 is not pressurized to the extent that the working fluid in the reservoir fluid chamber R1 can pass through the base member bypass passage 42 when the front fork is extended.

  In the above-described conventional front fork, a check valve 47 is provided on the side of the base member bypass passage 42 on the side of the reservoir internal fluid chamber R1, and only the movement of the working fluid from the pressure side working chamber B to the reservoir internal fluid chamber R1 is performed by this check valve 47. The base member side adjuster 43 is used exclusively for adjusting the compression side damping force, and the piston side adjuster 73 is used exclusively for adjusting the extension side damping force.

JP 2010-242965 A JP 2010-286076 A

  However, in the conventional front fork, as described above, the free piston 5 is urged by the coil spring S2 so that the cavitation of the compression side working chamber B can be prevented when the front fork is extended. Although the internal liquid chamber R1 is pressurized, the reservoir internal liquid chamber R1 is not pressurized to the extent that the working fluid in the reservoir internal liquid chamber R1 can pass through the base member bypass path 42 when the front fork is extended.

  Therefore, the base member side adjuster 43 cannot be used exclusively for adjusting the extension side damping force.

  Therefore, for example, as disclosed in Patent Document 2, one of the pair of left and right shock absorber members is dedicated to the extension side damping force adjustment and the other shock absorber member is dedicated to the compression side damping force adjustment. In this case, in the shock absorber member dedicated to adjusting the extension side damping force, the in-piston bypass path 72 must be used.

  In particular, as shown in Patent Document 2 and FIG. 5, when the inverted damper is accommodated, the piston side adjuster 72 is disposed on the wheel side, so that the damping force adjustment operation is performed from the lower side of the front fork. It must be difficult to work.

  Accordingly, an object of the present invention is to provide a front fork in which the base member side adjuster 43 can be used exclusively for adjusting the extension side damping force.

  Means for solving the above-mentioned problems include a shock absorber body comprising an outer tube and an inner tube slidably inserted into the outer tube, a damper accommodated in the shock absorber body, and the shock absorber. A reservoir formed in the body, and suspension means that is housed in the shock absorber body and constantly urges the shock absorber body in the extending direction, and the damper stands in the shock absorber body. A cylinder in which a working chamber filled with the working fluid is formed, a base member that partitions the working chamber and the reservoir, and a working fluid that is formed in the base member and communicates the working chamber and the reservoir. And a flow path that generates a predetermined damping force when passing through, a free piston that is opposed to the base member and is slidable in the axial direction is provided in the reservoir. An energizing means for pressurizing the in-reservoir liquid chamber with a force equal to or greater than the energizing force of the suspension means in a front fork in which a liquid chamber in the reservoir filled with a working fluid is formed between the piston and the base member; A bypass passage in the base member that connects the working chamber and the liquid chamber in the reservoir to bypass the flow path, a base member side adjuster that adjusts an opening amount of the bypass path in the base member, and a bypass in the base member And a check valve that is provided in the passage and allows only the movement of the working fluid from the liquid chamber in the reservoir to the working chamber.

  According to the present invention, the liquid chamber in the reservoir is pressurized with a force equal to or greater than the urging force of the suspension means, and the liquid chamber in the reservoir is pressurized with a force stronger than before. The working fluid in the liquid chamber can pass through the bypass passage in the base member.

  Furthermore, by providing the check valve in the base member bypass path, the base member side adjuster can be used exclusively for adjusting the extension side damping force.

It is a front view which partially cuts and shows one shock absorber member of the front fork concerning one embodiment of the present invention. It is a front view which partially cuts and shows the other buffer part of the front fork which concerns on one embodiment of this invention. It is a longitudinal cross-sectional view which expands and shows a part of one shock absorber member described in FIG. It is a longitudinal cross-sectional view which expands and shows a part of shock absorber member of the other shock absorber member described in FIG. It is a longitudinal cross-sectional view which shows the buffer member of the conventional front fork.

  A front fork showing an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, the front fork according to the present embodiment includes a shock absorber body including an outer tube 1 and an inner tube 2 that is slidably inserted into the outer tube 1. A damper D, a reservoir R formed in the shock absorber body, and a suspension means that is housed in the shock absorber body and constantly biases the shock absorber body in the extension direction.

  The damper D is a base member that divides the working chamber B and the reservoir R from the cylinder 3 in which working chambers A and B are formed in the shock absorber main body and are filled with the working fluid. 4 and channels 40 and 41 that are formed in the base member 4 and communicate with the working chamber B and the reservoir R to generate a predetermined damping force when the working fluid passes therethrough.

  The reservoir R is provided with a free piston 5 that faces the base member 4 and is slidable in the axial direction. The reservoir is filled with a working fluid between the free piston 5 and the base member 4. A liquid chamber R1 is formed.

  Furthermore, in the front fork according to the present embodiment, the urging means for pressurizing the liquid chamber R1 in the reservoir with a force equal to or greater than the urging force of the suspension means, the working chamber B, and the liquid chamber R1 in the reservoir. A base member bypass path 42 that communicates and bypasses the flow paths 40, 41, an adjuster 43 that adjusts the opening amount of the base member bypass path 42, and the reservoir provided in the base member bypass path 42. And a check valve 44 that allows only the movement of the working fluid from the internal liquid chamber R1 to the working chamber 4.

  Describing in detail below, the front fork according to the present embodiment is an inverted front fork that suspends a front wheel of a motorcycle or the like, and as shown in FIGS. It consists of a pair of buffer members F1, F2.

  One shock absorber member F1 shown in FIG. 1 is used for adjusting the extension side damping force, and the other shock absorber member F2 shown in FIG. 2 is used for adjusting the compression side damping force.

  As described above, the shock absorber member F1 for adjusting the extension side damping force shown in FIG. 1 includes a shock absorber body including the outer tube 1 and the inner tube 2 slidably inserted into the outer tube 1. Prepare.

  The outer tube 1 is connected to the vehicle body via a vehicle body side bracket (not shown), and a cap member 10 is attached to the inner periphery of the upper end portion in FIG.

  Further, the inner tube 2 is connected to the front wheel axle via a wheel-side bracket 20 which is attached to the outer periphery of the lower end portion and closes the lower opening in FIG.

  Further, an annular seal member 11 slidably contacting the outer periphery of the inner tube 2 is attached to the inner periphery of the lower end portion in FIG. 1 of the outer tube 1, and this seal member 11 is formed between the outer tube 1 and the inner tube 2. Close the opening of the cylindrical gap.

  By providing the above configuration, the shock absorber main body is hermetically sealed, so that it is possible to prevent the working fluid or gas accommodated in the shock absorber main body from leaking out of the shock absorber main body.

  The damper D accommodated in the shock absorber main body is an inverted damper, and the cylinder 3 is suspended from a cylindrical outer tube holding member 12 fixed between the cap member 10 and the outer tube 1. Is provided.

  An annular rod guide 30 is provided at the lower end side opening in FIG. 1 of the cylinder 3, and the piston rod 6 is projected and retracted in the cylinder 3 by being supported by an annular bearing member 30 a fitted to the inner periphery of the rod guide 30. To do.

  A piston 7 slidably in contact with the inner periphery of the cylinder 3 is held at the upper end of the piston rod 6 in FIG. 1, and an extension side working chamber A filled with a working fluid is formed on the lower side of the piston 7 in FIG. A pressure side working chamber B which is also filled with working fluid is formed on the upper side of the piston 7 in FIG.

  The extension side working chamber A and the pressure side action chamber B communicate with each other via an extension side channel 70 and a pressure side channel (not shown) formed in the piston 7, and the outlet of the extension side channel 70 is connected to the piston 7. The pressure-side channel can be opened and closed by a laminated leaf valve V1 stacked on the pressure-side working chamber B side, and the outlet of the pressure-side channel can be opened and closed by a check valve C1 stacked on the extension-side working chamber A side of the piston 7. Blocked.

  The pressure side working chamber B is partitioned from the reservoir internal fluid chamber R1 by the base member 4 held at the lower end of the base rod 8 suspended from the cap member 10, and this reservoir internal fluid chamber R1 is also a working fluid. Filled with.

  As shown in FIG. 3, the pressure side working chamber B and the reservoir internal liquid chamber R <b> 1 communicate with each other via an extension side channel 40 and a pressure side channel 41 formed in the base member 4, and an outlet of the extension side channel 40. Is closed by a leaf valve V3 laminated on the pressure side working chamber B side of the base member 4, and the outlet of the pressure side flow path 41 is a laminated leaf laminated on the reservoir internal liquid chamber R1 side of the base member 4. The valve V2 is closed so that it can be opened and closed.

  The base member 4 is provided with a base member bypass passage 42 that bypasses the flow paths 40 and 41 and communicates the pressure side working chamber B and the reservoir liquid chamber R1.

  A valve seat 42a to which a spherical check valve 44 is attached and detached is provided at the pressure-side working chamber B side opening of the base member bypass passage 42. The check valve 44 allows the pressure-side working chamber B to move from the reservoir internal fluid chamber R1. Only movement of the working fluid to is allowed.

  The base member bypass passage 42 communicates with a hollow portion (not shown) of the base rod 8 formed in a cylindrical shape, and the opening amount of the base member bypass passage 42 is inserted into the hollow portion. The needle valve 45 can be adjusted by advancing and retracting the tip of the needle valve 45 into the base member bypass passage 42.

  As shown in FIG. 1, the needle valve 45 is driven by a base member side adjuster 43 attached to the cap member 10 via a control rod 46 that is inserted into the hollow portion of the base lot 8 so as to be movable in the axial direction. .

  When the needle valve 45 moves forward and moves downward in FIGS. 1 and 3, the opening amount of the bypass 42 in the base member decreases, and when the needle valve 45 moves backward and moves upward in FIGS. The opening amount of the base member internal bypass passage 42 is increased.

  Further, as shown in FIG. 1, the reservoir internal liquid chamber R <b> 1 is partitioned from a cylinder internal air chamber R <b> 2 by a free piston 5, and this free piston 5 is formed in an annular shape so that the inner periphery of the upper part of the cylinder 3 in FIG. And slidably contact the outer periphery of the base rod 8.

  The cylinder inside air chamber R2 communicates with a cylinder outside air chamber R3 formed between the cylinder 4 and the shock absorber body through a communication hole 12a formed in the outer tube holding member 12, and a reservoir is provided together with the cylinder outside air chamber R3. Constructs an inside air chamber.

  The reservoir internal air chambers (R2, R3) are filled with gas while being compressed, and suspension means for always urging the shock absorber body in the extending direction, and urging the free piston 5 downward in the figure. It also serves as a means of force.

  That is, in the present embodiment, the reservoir R is configured to include a reservoir internal liquid chamber R1 and a cylinder internal air chamber R2 formed in the cylinder 3, and a cylinder external air chamber R3 formed outside the cylinder.

  Further, in the present embodiment, the buffer member F1 for adjusting the extension side damping force includes a balance spring 9 provided between the rod guide 30 and the piston 7, and the balance fork 9 has a certain amount of front fork. When it is extended, it is compressed to generate a predetermined spring reaction force.

  The balance spring 9 cancels the spring reaction force caused by the reservoir internal air chambers (R2, R3) when the front fork is fully extended, and helps the front fork to contract when the front fork is extended by a certain amount or more. To improve the ride comfort of motorcycles.

  Next, as shown in FIG. 2, the configuration of the damper member F2 for adjusting the compression side damping force that forms a front fork in a pair with the damper member F1 for adjusting the extension side damping force is as follows. Since the configuration of the shock absorber member F1 for adjustment is substantially the same, the same configuration is denoted by the same reference numeral and detailed description thereof is omitted here.

  As shown in FIG. 4, the shock-absorbing member F2 for adjusting the compression side damping force is a check valve 44 provided at the pressure-side working chamber B-side opening of the base member bypass passage 42 in the buffer member F1 for adjusting the extension-side damping force. (FIG. 3) is not provided.

  The buffer member F2 for adjusting the damping force on the compression side includes an annular plate-like check valve 47 that closes the opening in the reservoir liquid chamber R1 of the bypass passage 42 in the base member so as to be openable and closable. Only the fluid is allowed to move from the pressure side working chamber B to the reservoir internal fluid chamber R1 via the base member bypass passage 42.

  The configuration of the shock absorber member F2 for adjusting the compression side damping force other than the above is the same as that of the shock absorber member F1 for adjusting the extension side damping force.

  Next, the operation of the front fork in the present embodiment will be described. At the time of extension of the front fork in which the piston rod 6 retreats from the cylinder 3, the extension side working chamber A of both shock absorber members F1, F2 is pressurized, and the working fluid in the extension side action chamber A becomes a laminated leaf valve of the piston 7. V1 is pushed open, passes through the expansion side flow path 70 of the piston 7 and moves to the pressure side working chamber B.

  At this time, the working fluid that is deficient in the damper D with respect to the withdrawal of the piston rod 6 opens the leaf valve V3 of the base member 4 of both the shock absorber members F1 and F2 and passes through the extension side flow path 40 of the base member 4. Then, the check valve 44 of the buffer member F1 for adjusting the extension side damping force is opened, passes through the base member bypass passage 42, and moves from the reservoir internal fluid chamber R1 to the pressure side working chamber B.

  Then, when the working fluid passes through the extension side passages 70 and 40 of both the shock absorber members F1 and F2 and the bypass passage 42 in the base member of the shock absorber member F1 for adjusting the extension side damping force, an extension side damping force is generated. The extension side damping force can be adjusted by changing the opening amount of the base member bypass passage 42 in the buffer member F1 for adjusting the extension side damping force through the base member side adjuster 43.

  On the other hand, when the front fork in which the piston rod 6 enters the cylinder 3 is compressed, the pressure side working chamber B of both the shock absorber members F1 and F2 is pressurized, and the working fluid in the pressure side working chamber B becomes the check valve of the piston 7. C1 is opened, passes through the pressure side flow path (not shown) of the piston 7, and moves to the extension side working chamber A.

  At this time, the surplus working fluid in the damper D entering the piston rod 6 pushes and opens the laminated leaf valve V2 of the base member 4 of both the shock absorber members F1 and F2, thereby causing the pressure side flow path 41 (see FIG. 3 and FIG. 4), the check valve 47 of the shock absorber member F2 for adjusting the damping force on the compression side is opened, passes through the bypass passage 42 in the base member, and moves from the pressure side working chamber B to the reservoir liquid chamber R1. .

  Then, when the working fluid passes through the pressure side flow path 41 of both the shock absorber members F1 and F2 and the bypass passage 42 in the base member of the shock absorber member F2 for adjusting the pressure side damping force, a pressure side damping force is generated, and this pressure side damping force is generated. Can be adjusted by changing the opening amount of the bypass passage 42 in the base member through the base member side adjuster 43 in the shock absorber member F2 for adjusting the compression side damping force.

  That is, in the present embodiment, the compressed gas accommodated in the reservoir internal air chambers (R2, R3) always urges the front fork in the extending direction, and urges the free piston toward the base member side 4, The inside air chambers (R2, R3) also serve as suspension means and urging means.

  Accordingly, the reservoir internal fluid chamber R1 is pressurized with an urging force equivalent to that of the suspension means, so that the working fluid can pass through the base member communication passage 42 when the front fork is extended.

  Further, by providing the check valve 44 in the base member bypass path 42 of the buffer member F1 for adjusting the extension side damping force, the base member side adjuster 43 can be used exclusively for adjusting the extension side damping force.

  In addition, the front fork according to the present embodiment includes the check valve 44 and the leaf valve stacked on the base member 4 because the reservoir liquid chamber R1 is pressurized with a force equivalent to the urging force of the suspension means. The valve opening pressure of V3 can be set higher than that of the conventional check valve C3 (FIG. 5).

  In the present embodiment, among the pair of left and right shock absorber members, one shock absorber member F1 is used for adjusting the extension side damping force, and the other shock absorber member F2 is used for adjusting the compression side damping force. The in-piston bypass path 72 (FIG. 5) of each shock absorber member to be mounted can be eliminated.

  Therefore, there is no need to provide a piston-side adjuster 73 for adjusting the opening amount of the in-piston bypass passage 72, a needle or a control rod, and the front fork can be simplified and the front fork can be reduced in weight.

  In the present embodiment, the difference in the configuration of each shock absorber member F1, F2 is only the check valves 44, 47 provided in the base member bypass passage 42, and is used in both shock absorber members F1, F2. Many parts are shared, and the types of parts can be reduced.

  Although preferred embodiments of the present invention have been described in detail above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

  For example, in the above-described embodiment, an in-piston bypass path is not provided, but an in-piston bypass path may be provided and the opening amount thereof may be adjusted by a piston-side adjuster.

  In this case, the base member adjuster and the piston side adjuster can be selectively used depending on the piston speed.

  In this case, the base member side adjuster may be used exclusively for the extension side damping force adjustment, and the piston side adjuster may be used exclusively for the compression side damping force adjustment.

  In the above embodiment, the reservoir internal air chambers (R2, R3) are sealed while compressing the gas, and the reservoir internal air chambers (R2, R3) serve as the suspension means and the urging means. R1 is pressurized more than a predetermined amount, but the reservoir liquid chamber R1 may be pressurized with a force equal to or greater than the urging force of the suspension means by a coil spring or the like.

  In the above embodiment, since the reservoir internal air chambers (R2, R3) serve as the suspension means and the urging means, the reservoir liquid chamber R1 is pressurized with a force equivalent to the suspending means and the urging force. The liquid chamber R1 in the reservoir may be pressurized with a force larger than that of the suspension means.

A Stretching side working chamber B Pressure side working chamber C1, C2 Check valve V1, V2 Stacked leaf valve V3 Leaf valve R1 Reservoir liquid chamber R2 Cylinder air chamber R3 Cylinder air chamber 1 Outer tube 2 Inner tube 3 Cylinder 4 Base member 5 Free piston 6 Piston rod 7 Piston 8 Base rod 10 Cap member 12 Outer tube holding member 20 Wheel side bracket 40, 70 Extension side channel 41 Pressure side channel 42 Bypass channel in base member 43 Base member side adjuster 44, 47 Check valve 45 Needle valve 46 Control rod

Claims (4)

A shock absorber body comprising an outer tube and an inner tube slidably inserted into the outer tube; a damper housed in the shock absorber body; a reservoir formed in the shock absorber body; Suspension means housed in the shock absorber body and constantly biasing the shock absorber body in the extending direction;
The damper is formed in the base member, a cylinder in which a working chamber standing in the shock absorber body and filled with a working fluid is formed, a base member that partitions the working chamber and the reservoir, and A flow path that generates a predetermined damping force when the working fluid passes through the working chamber and the reservoir;
A free piston that is opposed to the base member and is slidable in the axial direction is provided in the reservoir, and a liquid chamber in the reservoir that is filled with a working fluid is formed between the free piston and the base member. Fork
A biasing means that pressurizes the liquid chamber in the reservoir with a force equal to or greater than a biasing force of the suspension means; a bypass passage in the base member that bypasses the flow path by communicating the working chamber and the liquid chamber in the reservoir; A base member side adjuster that adjusts the opening amount of the base member bypass passage, and a check valve that is provided in the base member bypass passage and only allows the working fluid to move from the liquid chamber in the reservoir to the working chamber. And a front fork. In the reservoir, gas is stored while being compressed on the side of the free piston opposite to the base member to form an air chamber in the reservoir, and the air chamber in the reservoir also serves as the suspension means and the urging means. The front fork according to claim 1 .   It consists of a pair of left and right shock absorber members, one shock absorber member having the configuration according to claim 1 or claim 2, wherein the one shock absorber member is a shock absorber member for adjusting the extension side damping force, and the other shock absorber. The front fork is characterized in that the container member is a shock absorber member dedicated to adjusting the compression side damping force. The other shock absorber member is composed of an outer tube and a shock absorber body that is slidably inserted into the outer tube, a damper accommodated in the shock absorber body, and the shock absorber body. A reservoir formed, and suspension means housed in the shock absorber body and constantly biasing the shock absorber body in the extending direction;
The damper is formed in the base member, a cylinder in which a working chamber standing in the shock absorber body and filled with a working fluid is formed, a base member that partitions the working chamber and the reservoir, and A flow path that generates a predetermined damping force when the working fluid passes through the working chamber and the reservoir;
A free piston that is opposed to the base member and is slidable in the axial direction is provided in the reservoir, and a liquid chamber in the reservoir that is filled with a working fluid is formed between the free piston and the base member. ,
A biasing means that pressurizes the liquid chamber in the reservoir with a force equal to or greater than a biasing force of the suspension means; a bypass passage in the base member that bypasses the flow path by communicating the working chamber and the liquid chamber in the reservoir; A base member side adjuster that adjusts the opening amount of the base member bypass passage, and a check valve that is provided in the base member bypass passage and allows only movement of the working fluid from the working chamber to the liquid chamber in the reservoir The front fork according to claim 3, further comprising:

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