JPH082510Y2 - Front fork - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a front fork, which is interposed between a vehicle body of a motorcycle or the like and an axle, and serves as a shock absorber and a fork for damping vibrations from a road surface.

[Conventional technology]

As this type of conventional front fork, for example, the second
The one shown in the figure has been developed.

This is because the vehicle body side tube is slidably inserted into the wheel side tube 1, the damper cylinder 3 stands up from the lower center of the wheel side tube 1, and the piston rod is movably inserted into the damper cylinder via a piston. A base valve 4 is provided below the cylinder 3.

The body 5 of the base valve 4 is fastened by a bolt 6 inserted from the center of the lower portion of the wheel side tube 1.

The body 5 and the bolt 6 of the base valve 4 are formed with axial passages 8 and 9 opening to the oil chamber 7 in the damper cylinder 3, and further, the bolt 6 is formed with a radial passage 10 and a groove 11. The passage 10 and the groove 11 communicate with the passage 9 in the axial direction, and also communicate with the reservoir 14 through the through holes 12 and 13 provided in the wheel side tube 1 and the valve 15 for generating the damping force.

Further, a ring nut 16 is provided below the body 5 of the base valve 4, and a seal is provided between the body 5 and the ring nut 16.
A seal 18 is interposed between the ring nut 16 and the bottom surface of the wheel-side tube 1 to prevent oil from leaking.

[Problems to be solved by the device]

In the above front fork, since the groove 11 is formed in the bolt 6, the strength of the bolt 6 is weak and it is a problem to mount it on a vehicle having a large external force such as vibration.

Further, the provision of the seals 17 and 18 above and below the ring nut 16 complicates the structure, and the lower seal 18 is likely to fall during assembly, resulting in poor assembly.

Therefore, an object of the present invention is to provide a front fork capable of preventing the strength of the bolt from being lowered, having a simple structure and being easy to assemble.

[Means for solving the problem]

In order to achieve the above object, the configuration of the present invention is such that the tube on the wheel side and the tube on the vehicle body side are slidably fitted, the damper cylinder stands up from the center of the lower part of the wheel side tube, and the piston is inserted in the damper cylinder. In the front fork where the piston rod is movably inserted and the body of the base valve is attached to the lower part of the damper cylinder via a bolt, the body of the base valve is sealed through a hole in the lower center of the wheel side tube. Fit, the body is fastened with bolts inserted in the wheel side tube,
A passage is formed in the body and the bolt, and a chamber defined by the body, the bolt and the wheel side tube is provided in the hole.
The oil chamber in the damper cylinder is communicated with the reservoir via the passage and the chamber.

[Action]

A chamber defined by the body, the bolt, and the wheel-side tube is used as a passage in place of the groove of the conventional bolt, and since the bolt has no groove, deterioration of the strength of the bolt is prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

A vehicle-side tube 2 which is an inner tube is slidably inserted into a wheel-side tube 1 which is an outer tube,
A damper cylinder 3 stands up from the lower center of the wheel side tube 1, and a piston rod is movably inserted into the damper cylinder 3 via a piston. The piston rod is connected to the vehicle body side tube 2 via an upper cap body. There is.

A base valve 4 is provided below the damper cylinder 3, and the damper cylinder 3 is connected via the base valve 4.
The oil chamber 7 inside communicates with the reservoir 14, and a compression side damping force is generated at the base valve 4.

The base valve 4 comprises a body 20, a piston 21 provided on the body 20, a pressure side leaf valve 22 and a check valve 25, and ports 23 and 24 provided on the piston 21 are opened and closed by the pressure side leaf valve 22 and the check valve 25, respectively. There is.

A base end portion 1a of the vehicle body side tube, which also serves as a bracket, is screwed to the lower portion of the vehicle body side tube 1. This proximal end 1a
May form a part of the vehicle body side tube 1 and may be integrally formed.

A hole 27 opening upward is formed in the center of the base end portion 1a,
The lower portion of the body 20 of the base valve 4 is fitted into the hole 27 via a seal 28, and the head portion of a bolt 29 inserted from the outside into the center of the base end portion 1a is a hole in the center of the body 20. It is inserted into 30 and screwed together, and the body 20 is fastened in the hole 27 of the base end portion 1a by the rotation of the bolt 29.

At this time, in the hole 27, the body 20, the bolt 29, and the base end portion
A chamber 31 which is a passage is defined by 1a.

The body 20 and the bolt 29 are formed with axial passages 26, 32 communicating with the oil chamber 7, and the passage 32 of the bolt 29 communicates with the chamber 31 via a passage 33 formed in the radial direction.

The outlet of the passage 33 of the bolt 29 is directly opened to the chamber 31, and a groove unlike the conventional case is not formed, so that the strength reduction of the bolt 29 is prevented.

A ring nut 34 is arranged below the body 20, and a seal 28 prevents oil from leaking from the outer periphery of the body 20. Therefore, the number of parts of the seal is small, the structure is simple, and the assemblability is good.

A passage 35 communicating with the chamber 31 and the reservoir 14 is formed in the base end portion 1a, and the passage area of the passage 35 is adjusted by a poppet-type damping valve 37 provided in the housing 36, and the passage 35 is throttled by the damping valve 37. The oil generates a damping force in the low speed range on the pressure side. In the middle / high speed range of the piston, a damping force is generated due to the bending of the pressure side leaf valve 22.

The damping valve 37 is screwed into the adjuster 38, and when the adjuster 38 is rotated from the outside, the damping valve 37 expands and contracts to adjust the opening of the passage 35 to make the damping force variable.

[Effect of device]

According to the present invention, the body, the bolt, and the wheel-side tube define a chamber that is a passage, and this chamber is communicated with the passage on the bolt side and the reservoir side. Therefore, it is necessary to form a groove at the outlet of the passage on the bolt. It is possible to prevent the deterioration of the strength of the bolt, no problem occurs even if it is mounted on a vehicle where external force such as vibration is strong, and the bolt can be easily processed.

Further, since only the seal is provided between the outer periphery of the body of the base valve and the inner periphery of the hole of the wheel side tube, the number of seals is small, the structure is simple, and the assemblability is good.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a front fork according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of a conventional front fork. 1 ... Wheel side tube, 2 ... Vehicle side tube, 3 ...
Damper cylinder, 4 ... Base valve, 7 ... Oil chamber,
14 …… reservoir, 20 …… body, 26, 32, 33 …… passage, 27
… Hole, 28 …… Seal, 29 …… Bolt, 31 …… Room.

Claims (1)

[Scope of utility model registration request] 1. A wheel side tube and a vehicle body side tube are slidably fitted together, a damper cylinder stands up from the lower center of the wheel side tube, and a piston rod is movably inserted into the damper cylinder via a piston. In a front fork in which the body of the base valve is attached to the lower part of the damper cylinder via a bolt, the body of the base valve is fitted through a seal into the hole in the center of the lower part of the wheel side tube. Fastened with a bolt inserted in the wheel side tube, a passage is formed in the body and the bolt, a chamber defined by the body, the bolt and the wheel side tube is provided in the hole, and the oil chamber in the damper cylinder is A front fork that communicates with the reservoir via a passage and a chamber.