JP6393569B2 - Front fork - Google Patents

Description

The present invention relates to a front fork.

  Conventionally, as a front fork that supports a steered wheel on the front side of a saddle vehicle, for example, a fork main body that includes a vehicle body side tube and an axle side tube and can be expanded and contracted, and a fork main body that is accommodated in the fork main body can be expanded and contracted. It is comprised with the damper which exhibits the damping force which suppresses.

  In such a front fork, the end of the axle side tube disposed on the axle side is closed by an axle bracket that supports the axle, and the end of the cylinder of the damper is used by using a bolt that penetrates the axle bracket. The bottom member to be closed is fastened to the axle bracket with a bolt to fix the damper in the fork main body (see, for example, Patent Document 1).

JP-A-8-303518

  In the work of bolting the bottom member to the axle bracket, it is necessary to insert the cylinder into the axle side tube and prevent the cylinder from rotating, but in general, the cylinder length of the damper is shorter than the axle side tube length. Since the cylinder cannot be gripped directly, it is necessary to insert a special jig that can be fitted to the cylinder or a component mounted on the cylinder and prevent the cylinder from rotating into the axle side tube.

  In addition, it is difficult to visually check the tip of the jig when fitting the tip of the jig to a cylinder that is completely buried in the axle-side tube or a part mounted on the cylinder. It will take.

  Therefore, in the conventional front fork, a special jig is required for the operation of fixing the damper to the axle side tube, and the operation is also a time-consuming operation, and improvement of the operation efficiency is required.

  Therefore, an object of the present invention is to provide a front fork that can improve the efficiency of assembly work.

  In order to achieve the above-described object, the front fork in the problem solving means of the present invention includes a protrusion provided at the end of the bottom member that closes one end of the cylinder of the damper, and an axle bracket that closes the end of the axle-side tube. And the protrusion is inserted into the insertion hole, and the bottom member is prevented from rotating with respect to the axle bracket by inserting the protrusion into the insertion hole. The bottom member can be firmly bolted to the axle bracket by applying a predetermined tightening torque to the axle bracket.

In addition, a reservoir provided outside the damper inside the fork main body and the cylinder is communicated with a communication passage formed through the bottom member, bolt and axle bracket and an insertion hole, and a variable damping valve is provided in the middle of the communication passage. When equipped, the damping force on the pressure side of the front fork can be made variable, the insertion hole can be used effectively, and the processing cost of the front fork can be reduced . Furthermore, is an elongated hole having two surfaces insertion hole with each other orientations parallel to each other, if it is a shape having a dihedral shape of the projecting portion is opposed to the two surfaces, the projection of the insertion hole Insertion is further facilitated, and the assembly work efficiency is further improved.

  Furthermore, when the cross-sectional shape of the protrusion is a square, the processing of the protrusion is simple and cost reduction, and the ease of the insertion work into the insertion hole of the protrusion during assembly processing Excellent.

  Therefore, according to the front fork of the present invention, the efficiency of the assembly work can be improved.

It is sectional drawing of the front fork in one embodiment of the present invention. It is sectional drawing of the protrusion inserted in the insertion hole in the front fork of one embodiment of the present invention. It is a partially expanded sectional view in the front fork of one embodiment of the present invention.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, the front fork 1 according to the present embodiment includes an outer tube 2 as a vehicle body side tube connected to a vehicle body of a saddle riding vehicle (not shown) and an axle side tube connected to an axle of the saddle vehicle. The fork main body F which has the inner tube 3 and can be contracted, the axle bracket A which closes the end of the inner tube 3, the damper D accommodated in the fork main body F, and the cylinder 10 in the damper D in the axle bracket A And a so-called telescopic type. The front fork 1 suppresses the expansion and contraction by a damping force generated by the damper D when the outer tube 2 and the inner tube 3 are expanded and contracted relative to each other in the vertical direction in FIG. ing.

  Hereinafter, each part will be described. The outer tube 2 is closed at the upper end in FIG. 1 by a head cap 5 attached to the upper end, and the inner tube 3 is closed at the lower end by the axle bracket A attached to the lower end in FIG. And the fork main body F is comprised by inserting the inner tube 3 in the outer tube 2 through a bearing not shown so as to be slidable. The fork main body F is extendable and the inside of the fork main body F is sealed by a seal member 6 provided between the outer tube 2 and the inner tube 3.

  As shown in FIG. 1, the front fork 1 of the present embodiment has a so-called inverted structure in which an outer tube 2 is arranged upward to form a vehicle body side tube and an inner tube 3 is arranged downward to form an axle side tube. Constructed as a front fork of the mold, conversely, the outer tube 2 is disposed below and the lower end of the outer tube 2 is closed with the axle bracket A, and the inner tube 3 is disposed upward to form the vehicle body side tube. It may be configured as a so-called upright front fork.

  The damper D is moved into the cylinder 10, the piston 11 that is slidably inserted into the cylinder 10, and divides the cylinder 10 into an expansion side chamber R <b> 1 and a pressure side chamber R <b> 2. A rod 12 which is freely inserted and connected to the piston 11 and whose one end, which is the upper end in FIG. 1, protrudes out of the cylinder 10, and one end which is the upper end in FIG. A rod guide 13 for guiding and a bottom member 14 for closing the lower end of the cylinder 10 in FIG.

  The piston 11 includes a damping passage 15 that includes a damping valve 16 that communicates the extension side chamber R1 and the pressure side chamber R2 and provides resistance to the flow of liquid passing therethrough. In this case, the attenuation passage 15 allows a bidirectional flow of a liquid flow from the expansion side chamber R1 to the compression side chamber R2 and a liquid flow from the compression side chamber R2 to the expansion side chamber R1, but from the expansion side chamber R1 to the compression side. The passage may be constituted by a plurality of passages including a passage allowing only the liquid flow toward the chamber R2 and a passage allowing only the liquid flow toward the extension side chamber R1 from the compression side chamber R2.

  Further, as shown in FIG. 3, the bottom member 14 closes the opening at the other end which is the lower end of the cylinder 10 in FIG. A protrusion 18 that protrudes downward from the lower end in the axial direction and a valve holding shaft 19 that protrudes in the axial direction upward from the upper end of the disk portion 17 are provided. The bottom member 14 includes a screw hole 20 that opens from the lower end of the protrusion 18 and communicates with the disk portion 17. The screw hole 20 is formed by a through-hole 21 that opens from the upper end of the valve holding shaft 19. It communicates with R2.

  A valve disc 22 is attached to the valve holding shaft 19, and a gap L defined from the pressure side chamber R <b> 2 is formed between the valve disc 22 and the disc portion 17 of the bottom member 14. The gap L communicates with the outside of the cylinder 10, that is, inside the fork main body F and outside the damper D by a hole 10 a provided in the cylinder 10. The liquid is filled with the gas inside the fork main body F and outside the damper D, and the space inside the fork main body F and outside the damper D is used as the reservoir R. Therefore, the gap L communicates with the reservoir R through the hole 10a.

  The valve disk 22 includes a pressure-side damping passage 23 having a pressure-side damping valve 24 that allows only a liquid flow from the pressure-side chamber R2 to the outside of the cylinder 10 and provides resistance to the flow, and a pressure-side chamber from the outside of the cylinder 10. And a suction passage 25 having a check valve 26 that allows only the flow of liquid toward R2.

In the damper D configured as described above, the upper end of the rod 12 in FIG. 1 is connected to the outer tube 2 which is a vehicle body side tube via the head cap 5, and the bottom member 14 is fastened to the axle bracket A with bolts B. The cylinder 10 is connected to the inner tube 3 which is an axle side tube. Thus, the damper D which is connected to the outer tube 2 and the inner tube 3 is accommodated in the fork main body F, and expansion and contraction of the fork main body F to move relative to the outer tube 2 and the inner tube 3 are axially together It is designed to expand and contract.

  As shown in FIGS. 1 and 3, the axle bracket A is a C-shaped body that closes the lower end of the inner tube 3 and a C-type that is provided below the main body 30 and grips the axle of a straddle vehicle (not shown). And a grip portion 31. Although not described in detail, a lateral side of the main body portion 30 is provided with a brake attachment portion to which a brake for braking the wheel is attached and a fender attachment portion to which the fender is attached. Further, the main body 30 is provided with an insertion hole 30a that is a long hole that opens from the upper end facing the fork main body F, and a bolt insertion hole 30b that opens from the lower end facing the grip portion 31 and communicates with the insertion hole 30a. It has been. As shown in FIG. 2, the insertion hole 30a has two surfaces facing each other in parallel, and is a rounded rectangle with arcuate surfaces on both sides of the two surfaces. The depth of the insertion hole 30a is equal to or greater than the axial length of the protrusion 18 of the bottom member 14. When the protrusion 18 is inserted into the insertion hole 30a, the two opposing faces of the square protrusion 18 face the two parallel faces of the insertion hole 30a, and the bottom member 14 rotates with respect to the axle bracket A. Stopped.

  In order to fasten the bottom member 14 with the bolt B to the axle bracket A configured as described above, the following is performed. First, the damper D is inserted into the inner tube 3 to which the axle bracket A is attached, and the protrusion 18 is inserted into the insertion hole 30a. At this time, since the protrusion 18 has a square cross section, even if the damper D is rotated in the same direction in the circumferential direction with respect to the inner tube 3, the protrusion 18 is inserted at a maximum of 90 degrees. The insertion into the hole 30a is completed.

  Thus, with the protrusion 18 inserted into the insertion hole 30a, the bolt B is inserted into the bolt insertion hole 30b from below the main body 30 of the axle bracket A, and the screw hole 20 provided in the bottom member 14 is inserted. To be twisted into.

Once inserted the projections 18 into the insertion hole in 30a, since the bottom member 14 is prevented from rotating relative to the accession scan Le bracket A, the bolt B will crowded screw into the screw hole 20, also increasing the tightening torque The bottom member 14 does not idle. As a result, a predetermined tightening torque can be applied to the bolt B, and the bottom member 14 can be firmly bolted to the axle bracket A. Thus, the bottom member 14 is fixed to the axle bracket A, and the cylinder 10 is connected to the inner tube 3.

  As can be understood from the above, if the rotation is formed by the protrusion 18 and the insertion hole 30a, the bolt B can be fixed without using any other jig for locking the cylinder 10 or the bottom member 14. It can be attached to the bottom member 14 with a tightening torque of Therefore, according to the front fork 1 of the present invention, the work efficiency of the assembly work of the front fork 1 can be dramatically improved.

  In addition, since it is only necessary to insert the protrusion 18 into the insertion hole 30a to prevent rotation, the shape of the protrusion 18 and the insertion hole 30a may be matched with each other if not circular. As described above, two surfaces parallel to the insertion hole 30a are formed, and the protrusion 18 may have a shape having two parallel surfaces opposite to the two surfaces. Therefore, the cross-sectional shape of the protrusion 18 may be a hexagon or an octagon with respect to the shape of the insertion hole 30a. However, since it is possible to reduce the cost by adopting a shape that is easy to process when processing the protrusion 18, if a square is used, the cost can be reduced and the protrusion 18 can be inserted into the insertion hole 30 a during assembly processing. Excellent in ease of plugging work.

  In addition, since the insertion hole 30a is a long hole and the width in the longitudinal direction is longer than the protrusion 18, the protrusion 18 can be easily inserted into the insertion hole 30a. The efficiency of assembly work can be further improved.

  Further, in the case of the present embodiment, the axle bracket A includes a pressure side variable damping passage 30c that opens from the side of the bolt insertion hole 30b, and a variable damping valve 40 that is provided in the middle of the pressure side variable damping passage 30c. .

  As shown in FIG. 3, the variable damping valve 40 is opened from the side of the axle bracket A and is connected to the pressure-side variable damping passage 30c through the insertion hole 30a. And a valve body 40b that can open and close the pressure side variable damping passage 30c and changes the flow passage area of the passage 30c. Therefore, when the valve body 40b is rotated from the outside, the opening and closing of the pressure side variable attenuation passage 30c and the change of the flow passage area are possible.

  Further, the pressure side variable damping passage 30c is connected to the screw hole 20 and the through hole 21 provided in the bottom member 14 by an in-bolt communication hole 41 that opens from the tip of the bolt B and communicates to the side of the bolt B. Further, the insertion hole 30 a is a long hole, and the longitudinal width thereof is longer than the outer peripheral diameter of the cylinder 10, so that it is not closed by the cylinder 10 and communicated with the reservoir R. Therefore, in this case, the valve hole 40a, the pressure-side variable damping passage 30c, the bolt communication hole 41, the screw hole 20, and the through hole 21 form a communication path P that communicates the inside of the cylinder 10 with the insertion hole 30a.

  When the front fork 1 configured in this manner exhibits an extension operation, the damper D also extends. When the damper D extends, the piston 11 moves upward in FIG. 1 with respect to the cylinder 10, the expansion side chamber R1 is compressed, and the compression side chamber R2 is expanded. The liquid passes through the damping passage 15 from the compressed expansion chamber R1 to the expanded compression chamber R2, and the liquid L and the suction are sucked into the compression chamber R2 in which the liquid corresponding to the volume of the rod 12 exiting the cylinder 10 is expanded. It is supplied from the reservoir R through the passage 25. Therefore, the pressure in the extension side chamber R1 rises, the pressure in the pressure side chamber R2 becomes equal to the pressure in the reservoir R, a pressure difference is generated, the damper D generates a damping force, and the front fork 1 extends. It is suppressed.

On the contrary, when the front fork 1 is contracted, the damper D is contracted. When the damper D contracts, the piston 11 moves downward in FIG. 1 with respect to the cylinder 10, the compression side chamber R2 is compressed, and the expansion side chamber R1 is expanded. Liquid to expansion side chamber R1 which is enlarged from the compression side chamber R 2 to be compressed to move through the damping passage 15. In addition, the liquid corresponding to the volume of the rod 12 entering the cylinder 10 enters the gap L from the pressure side chamber R2, and further the communication path P when the variable damping valve 40 opens the pressure side variable damping path 30c. And is discharged to the reservoir R. Therefore, the damper D generates a damping force so that the pressure in the compression side chamber R2 and the extension side chamber R1 rises to prevent the rod 12 from entering the cylinder 10, and the contraction of the front fork 1 is suppressed. .

If the flow area of the pressure-side variable damping passage 30c is changed by the variable damping valve 40, the pressure in the cylinder 10 when the damper D contracts can be adjusted, and the pressure-side damping force of the front fork 1 can be made variable. Since the communication path P communicates with the reservoir R through the insertion hole 30a, the insertion hole 30a can be effectively used separately, and there is no need to provide another path for communicating the communication path P with the reservoir R. The processing cost of the fork 1 can be reduced . This is the end of the description of the embodiments of the present invention, but the scope of the present invention is not limited to the details shown or described.

DESCRIPTION OF SYMBOLS 1 Front fork 2 Outer tube as a vehicle body side tube 3 Inner tube as an axle side tube 10 Cylinder 12 Rod 14 Bottom member 18 Protrusion part 30a Insertion hole 40 Variable damping valve A Axle bracket B Bolt D Damper F Fork main body P Communication path R reservoir

Claims (4)

A fork main body having a vehicle body side tube and an axle side tube and capable of contraction;
An axle bracket that closes an end of the axle-side tube;
A damper housed in the fork main body having a cylinder, a bottom member that closes one end of the cylinder, and a rod that is movably inserted into the cylinder from the other end side of the cylinder;
An insertion hole that opens from an end of the axle bracket facing the fork body;
A protrusion that is provided at an end of the bottom member and is inserted into the insertion hole so that the bottom member is prevented from rotating with respect to the axle bracket;
A bolt that passes through the axle bracket and the protrusion and is screwed to the bottom member to connect the damper to the axle-side tube;
A reservoir that is provided inside the fork body and outside the damper and faces the insertion hole;
A communication passage formed between the bottom member, the bolt, and the axle bracket and communicating the inside of the cylinder and the insertion hole;
A front fork provided with a variable damping valve provided in the middle of the communication path and capable of adjusting a flow path area by an external operation . A fork main body having a vehicle body side tube and an axle side tube and capable of contraction;
An axle bracket that closes an end of the axle-side tube;
A damper housed in the fork main body having a cylinder, a bottom member that closes one end of the cylinder, and a rod that is movably inserted into the cylinder from the other end side of the cylinder;
An insertion hole that opens from an end of the axle bracket facing the fork body;
A protrusion that is provided at an end of the bottom member and is inserted into the insertion hole so that the bottom member is prevented from rotating with respect to the axle bracket;
A bolt that penetrates the axle bracket and the protrusion and is screwed to the bottom member, and that connects the damper to the axle side tube;
The insertion hole is a long hole having two surfaces facing each other in parallel,
The shape of the protrusion is a shape having two surfaces facing the two surfaces.
A front fork characterized by that. The insertion hole is a long hole having two surfaces facing each other in parallel,
The shape of the protrusion, the front fork according to claim 1, characterized in that it is a shape having two opposing surfaces on the two surfaces. The front fork according to any one of claims 1 to 3, wherein a cross-sectional shape of the protrusion is a square.

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