JPH056236U - Front fork - Google Patents

Abstract

(57) [Abstract] [Purpose] It is easy to process the inner circumference of the vehicle body side tube, does not reduce the strength, and aims at cost reduction. [Structure] Wheel-side tube 11 in vehicle-side tube 10
Is slidably inserted, two upper and lower bearings 19 and 20 are provided on the inner circumference of the vehicle body side tube 10, and the wheel side tube 11 is slidably in contact with the bearings 19 and 20. Base tube portion 10a and distal tube portion 10 connected to the base tube portion 10a
b, and the annular grooves 17 and 18 are formed above and below the inner circumference of the proximal tube portion 10a, and the bearings 19 and 20 are held in the annular grooves 17 and 18, respectively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a front fork that doubles as a shock absorber and a fork that is interposed between a vehicle body side and an axle of a motorcycle to damp vibrations from the road surface.

[0002]

[Prior Art]

 As this type of front fork, for example, a large number of front forks disclosed outside of Japanese Utility Model Laid-Open No. 2-145293 and Japanese Utility Model Laid-Open No. 3-17441 have been developed.

In these known front forks, a vehicle body side tube and a wheel side tube are fitted to each other, a lower bearing is provided on a lower inner circumference of the vehicle body side tube, and an upper bearing is provided on an upper outer circumference of the wheel side tube. The wheel side tube is slidably inserted into the vehicle body side tube through these bearings.

The vehicle body side tube is usually made of an aluminum material, and the wheel side tube is usually made of an iron material.

Therefore, when the upper bearing on the upper outer circumference of the wheel side tube slides on the inner circumference of the vehicle body side tube made of a soft aluminum-based material, abrasion powder is generated from the vehicle body side tube, and this causes abrasion powder in oil. When mixed, it adversely affects the slidability and the generation of damping force, which may impair the durability of the vehicle body side tube.

For this reason, conventionally, as shown in FIG. 3, a tapered surface 2 is formed on the lower inner circumference of a body-side tube 1 made of a soft material, and annular grooves 3 and 4 are formed above and below the tapered surface 2. A bearing in which upper and lower bearings 5 and 6 are press-fitted into these annular grooves 3 and 4 and a wheel-side tube 7 is guided by these bearings 5 and 6 has been developed.

[0007]

In the newly developed front fork described above, since the bearing of the vehicle body side tube is in sliding contact with the outer periphery of the soft wheel side tube, abrasion powder is prevented from being generated, but the tapered surface 2 There is a problem that it becomes difficult to process the annular grooves 3 and 4.

That is, the dimension L for processing the tapered surface 2 is long, and it is difficult to process the taper surface 2 from below, and it is difficult to ensure accuracy.

Further, by providing the tapered surface 2 and the annular grooves 3 and 4, there is a problem that the wall thickness of the vehicle body side tube 1 is reduced and the strength is reduced.

Furthermore, since the bearings 5 and 6 provided in the upper and lower annular grooves 3 and 4 have different thicknesses, it is impossible to unify the bearings, which not only increases the cost but also makes it difficult to manage the parts.

Therefore, an object of the present invention is to provide a front fork in which the inner circumference of the vehicle body side tube can be easily processed, the strength is not reduced, and the cost is reduced.

[0012]

[Means for Solving the Problems]

 In order to achieve the above object, the configuration of the present invention is such that the wheel side tube is slidably inserted into the vehicle body side tube, two upper and lower bearings are provided on the inner circumference of the vehicle body side tube, and the wheel side tube is provided. In the front fork that is in sliding contact with the bearing, the body-side tube is composed of a proximal tube section and a distal tube section connected to the proximal tube section, and annular grooves are formed above and below the inner circumference of the proximal tube section. However, the bearing is held in each annular groove.

[0013]

[Action]

 Since the vehicle body side tube is divided into two parts, the base end tube part is shorter than the entire length, and the wheel side tube slides on the vertical bearing provided on the inner circumference of the base end tube part.

Since the proximal end tube portion is short, the inner circumference can be easily processed, the bearings can be easily mounted, and the depths of the upper and lower annular grooves can be made substantially uniform, so that the upper and lower bearings can have the same wall thickness.

[0015]

【Example】

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

A wheel side tube 11 is slidably inserted into a vehicle body side tube 10, a damper cylinder 12 is erected from below in the wheel side tube, and a piston 13 is provided in the damper cylinder 12 via a piston 13. The piston rod 14 is movably inserted, and the upper end of the piston rod 14 is connected to the vehicle body side tube 10 via a cap 15.

A suspension spring 16 is interposed between the upper portion of the damper cylinder 12 and the cap 15 to constantly urge the vehicle body side tube 10 and the piston rod 14 in the extending direction.

The vehicle-body-side tube 10 is divided into two parts and is composed of a base end tube part 10a and a tip end tube part 10b joined to an upper part of the base end tube part 10a.

The upper end of the proximal end tube portion 10a is formed in a tubular shape, and the lower end of the distal end tube portion 10b is fitted into the inner circumference 25 of the upper end portion of the tubular shape, and is joined by press fitting, screw connection, welding, etc. It is sealed with a seal 24.

Annular grooves 17 and 18 are formed above and below the inner circumference of the body of the proximal end tube 10a, and upper and lower bearings 19 and 20 are press-fitted and held in these annular grooves 17 and 18, respectively. Bearings 19 and 20 are in sliding contact with the outer circumference of the wheel-side tube 11 to guide the sliding of the wheel-side tube 11.

The tip tube portion 10b is made of an iron material, and the base tube portion 10a is made of an aluminum material.

A cap 15 is provided at the upper end of the vehicle body side tube 10 composed of the distal end tube portion 10 b and the proximal end tube portion 10 a, a seal 23 is attached to the inner periphery of the lower end, and an upper bracket 21 and an under bracket 22 are provided. It is connected to the car body side.

[0023]

[Effect of the device]

 According to the present invention, the following effects can be obtained.

A) Since the vehicle body side tube is composed of a proximal end tube portion and a distal end tube portion, and the upper and lower bearings are provided on the inner circumference of the proximal end tube portion, the proximal end tube portion becomes shorter than the entire length, Grooves and inner circumferences can be processed from both the top and bottom of the base end tube, which is easy and accurate, and bearings can be easily mounted.

B) Since the inner circumference and the groove of the tip tube portion can be processed from both the upper and lower sides, the depth and width of the upper and lower annular grooves can be uniformly formed, so that the upper and lower shafts held in the annular groove can be formed. The thickness and length of the bearing can be made uniform, and the bearings can be unified, the cost can be reduced, and the parts management can be improved.

C) Since the vehicle body side tube is divided into two parts, the material of the proximal end tube portion and the material of the distal end tube portion can be made separate, and cost bounce can be achieved.

D) Since the inner circumference of the proximal end tube portion can be easily and uniformly processed, it is possible to secure the thickness of the vehicle body side tube portion and prevent the strength from decreasing.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a front fork according to the present invention.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a partially enlarged cross section of a conventional front fork.

[Explanation of symbols]

 10 Body side tube 10a Base end tube part 10b Tip tube part 11 Wheel side tube 17,18 Annular groove 19,20 Bearing

Claims (1)

[Claims for utility model registration] [Claim 1] A wheel-side tube is slidably inserted into a vehicle-body-side tube, two upper and lower bearings are provided on the inner circumference of the vehicle-body-side tube, and the wheel-side tube is used as the bearing. In the sliding front fork, the vehicle body side tube is composed of a proximal end tube part and a distal end tube part connected to the proximal end tube part, and annular grooves are formed above and below the inner circumference of the proximal end tube part. A front fork characterized by holding a bearing in an annular groove.