WO2025163843A1 - Shock absorber, manufacturing method therefor, and front fork - Google Patents

Abstract

A shock absorber (10) has a bracket (20) in which a columnar hole (22b), which is a cylindrical hole, is formed, and a cylindrical tube (31) that is supported by the bracket (20) and extends downward from the columnar hole (22b). A fixing part (F1) in which the tube (31) is fixed to the bracket (20) is formed at a position avoiding the lower end of the bracket (20). Preferably, the fixing part (F1) is configured by welding the upper end of the tube (31) to the bracket (20).

Description

Shock absorber, manufacturing method thereof, and front fork

The present invention relates to manufacturing technology for shock absorbers including front forks.

Patent Document 1 discloses a conventional technology relating to shock absorbers, particularly front forks for saddle-ride vehicles.

The front fork shown in Patent Document 1 includes a bracket that rotates with the handlebar pipe when it is rotated, and a shock absorber body whose upper end is inserted into the bracket and capable of generating a damping force. The front wheel is connected to the lower end of the shock absorber body.

The shock absorber body includes a cylindrical tube located at the top end, which is inserted into a bracket. The portion of the bracket where the tube is inserted is welded, thereby securing the tube to the bracket.

Japanese Patent Application Publication No. 8-295278

When a saddle-type vehicle is traveling, unevenness in the road surface can cause forces in the front and rear directions to be applied to the front wheel. These forces act in a way that causes the tube to bend relative to the bracket. From the perspective of extending the lifespan of a vehicle, applying a large load to the area where the tube is joined to the bracket is undesirable. In other words, it is desirable to reduce the load on the fixing part where the tube is fixed to the bracket.

The objective of the present invention is to provide a shock absorber that can reduce the load on the fixed part.

After extensive research, the inventor discovered that forming the fixing part at a position that avoids the lower end of the bracket reduces the load on the fixing part. The present invention was completed based on this discovery.

The following describes this disclosure.

According to the present disclosure, a bracket having a cylindrical hole portion that is a cylindrical hole;
a cylindrical tube supported by the bracket and extending downward from the cylindrical hole,
The fixing portion at which the tube is fixed to the bracket is formed at a position that avoids a lower end of the bracket.

The present invention provides a shock absorber that can reduce the load on the fixed part.

FIG. 2 is a front view showing the main part of the shock absorber according to the first embodiment. FIG. 2 is an enlarged view of a main part of FIG. 1 . 3A to 3C are diagrams illustrating a manufacturing method of the shock absorber shown in FIG. 2 . FIG. 10 is an enlarged cross-sectional view of a main part of a shock absorber according to a second embodiment. FIG. 11 is an enlarged cross-sectional view of a main part of a shock absorber according to a third embodiment. FIG. 10 is an enlarged cross-sectional view of a main part of a shock absorber according to a fourth embodiment. FIG. 10 is an enlarged cross-sectional view of a main part of a shock absorber according to a fifth embodiment.

Embodiments of the present invention will be described below with reference to the attached drawings. Note that in the description, left and right refer to left and right relative to the occupant of the saddle-ride type vehicle, and front and rear refer to front and rear relative to the direction of travel of the saddle-ride type vehicle. In addition, in the drawings, Fr refers to front, Rr refers to rear, Le refers to left as seen from the occupant, Ri refers to right as seen from the occupant, Up refers to top, and Dn refers to bottom. The embodiments shown in the attached drawings are one example of the present invention, and the present invention is not limited to this embodiment.

Example 1
Please refer to Figure 1. Figure 1 shows the main parts of a shock absorber 10. The shock absorber 10 is used, for example, as a front fork of a saddle-ride type vehicle on which a rider sits astride. The shock absorber 10 has a bracket 20 that rotates in conjunction with the rider operating the handlebars, and shock absorber bodies 30, 30 that are supported by the bracket 20 and connected to the front wheel.

It is also possible for only one shock absorber body 30, 30 to be supported by the bracket 20. In this case,

The bracket 20 has a round rod-shaped upper bracket 21 that connects to the handle, and a lower bracket 22 into which the lower end of the upper bracket 21 is inserted and which supports the shock absorber main bodies 30, 30.

The lower bracket 22 is formed with an upper bracket insertion hole 22a, into which the upper bracket 21 is inserted, and a shock absorber body insertion hole 22b, into which the shock absorber body 30 is inserted. The upper bracket insertion hole 22a and the shock absorber body insertion hole 22b are both cylindrical holes. Hereinafter, the shock absorber body insertion hole 22b may be referred to as the cylindrical hole 22b.

Note that the upper bracket insertion hole 22a does not necessarily have to be a cylindrical through-hole. It may be a hole with a bottom, or an elliptical or polygonal hole.

See Figure 2. The shock absorber body 30 is shown only in the form of a cylindrical tube 31 and a lid 32 closing the top end of the tube 31, which are its essential parts. As long as the shock absorber body 30 generates a damping force when it expands and contracts, the fluid filled inside the tube 31 and the relative positions of the upper and lower tubes, such as upright or inverted, can be selected as desired.

In addition to the tube 31 and lid 32, the shock absorber body 30 may have a known configuration, including a lower cylinder positioned below the tube 31 and capable of moving up and down relative to the tube 31, a piston located inside either the upper or lower tube that generates a damping force when fluid passes through it, and a spring that acts to return the tube 31 to a predetermined position.

The upper end of the tube 31 is located approximately flush with the upper surface of the bracket 20, and the tube 31 is joined to the bracket 20 by welding. The portion where the tube 31 is fixed to the bracket 20 is hereinafter referred to as the "fixed portion F1." In Figure 2, the fixed portion F1 is formed by welding the upper end of the tube 31 to the bracket 20. The fixed portion F1 is formed continuously on the upper surface of the bracket 20 and the upper end surface of the tube 31, and is formed around the entire upper end of the tube 31. It can also be said that the fixed portion F1 is formed in a position that avoids the lower end of the bracket 20.

The upper end of the tube 31 may be located below the upper surface of the bracket 20, or may be located above the upper surface of the bracket 20. If the upper end of the tube 31 is located below the upper surface of the bracket 20, a fixing portion is formed from the cylindrical hole portion 22b to the upper end surface of the tube 31. If the upper end of the tube 31 is located above the upper surface of the bracket 20, a fixing portion is formed from the upper surface of the bracket 20 to the side of the tube 31.

The upper surface of the lid 32 is located approximately flush with the upper surface of the bracket 20 and the upper end of the tube 31, and the lid 32 is joined to the tube 31 by welding.

The upper surface of the lid 32 may be located below the upper end surface of the tube 31, or may be located above the upper end surface of the tube 31.

Refer to Figure 3. A manufacturing method for shock absorber 10 (see Figure 2) will be described. To manufacture shock absorber 10, a lid insertion process is performed in which lid 32 is inserted by press-fitting it into the upper end of tube 31, and a tube insertion process is performed in which tube 31 is inserted into the upper end of bracket 20. Either the lid insertion process or the tube insertion process can be performed first.

Note that the lid insertion process and the tube insertion process can also be performed by methods other than press-fitting. Furthermore, the lid insertion process and the tube insertion process can each be performed by a different insertion method.

Next, a welding process is performed in which the lid 32 is welded to the tube 31 and the tube 31 is welded to the bracket 20. The welding process is performed by laser welding, for example, using a laser welder 41. It is preferable that the lid 32 and the tube 31 are welded around their entire circumference. Either the lid 32 or the tube 31 can be welded first, but it is preferable that these welding processes be performed consecutively or simultaneously.

It should be noted that welding can be performed using a welding method other than laser welding. In other words, any welding method can be selected. The lid 32 or the tube 31 may also be welded using an intermittent welding method.

Example 2
Next, a second embodiment will be described with reference to the drawings.

See Figure 4. The shock absorber 10A according to Example 2 differs from the shock absorber 10 described in Figure 2 in the position at which the tube 31A of the shock absorber main body 30A is fixed. The other basic configuration is the same as the shock absorber 10 described above. For configuration common to the shock absorber 10, the same reference numerals will be used and detailed explanations will be omitted where appropriate.

The upper end of tube 31A is located at a position lower than the upper surface of bracket 20. Meanwhile, the upper surface of lid 32A is located at approximately the same height as the upper surface of bracket 20. The area surrounded by bracket 20, tube 31A, and lid 32A is filled with a bead. Fixing portion F2 is formed by welding tube 31A to bracket 20.

Example 3
Next, a third embodiment will be described with reference to the drawings.

See Figure 5. The shock absorber 10B of Example 3 uses fall prevention members 51B and 52B that prevent the tube 31B from falling from the bracket 20B. The other basic configuration is the same as that of the shock absorber 10 described above. For components that are the same as those of the shock absorber 10, the same reference numerals will be used and detailed descriptions will be omitted where appropriate.

The lower bracket 22B that constitutes bracket 20B is formed with a first through-hole portion 22Bc that penetrates radially from the outer peripheral surface toward the axis, a second through-hole portion 22Bd that penetrates tangentially to the outer peripheral surface, and a seal storage groove 22Be for storing the seal member 53B.

The outer surface of the tube 31B that constitutes the shock absorber main body 30B is formed with a first tube side hole 31Ba, which is a bottomed hole that continues from the first through hole portion 22Bc and has the same inner diameter as the first through hole portion 22Bc, and a second tube side hole 31Bb that is opened along the second through hole portion 22Bd and has a circular shape that continues from the second through hole portion 22Bd.

One of the fall prevention members, 51B, is formed by a cylindrical pin. The fall prevention member 51B passes through the first through-hole portion 22Bc and its tip reaches the first tube-side hole portion 31Ba.

The other fall prevention member 52B is formed by a cylindrical pin. The fall prevention member 52B passes through both the second through-hole portion 22Bd and the second tube-side hole portion 31Bb.

By inserting the fall suppression members 51B and 52B, it is possible to prevent the tube 31B from falling even if a load is applied to the tube 31B in the falling direction. At least one of the fall suppression members 51B and 52B needs to be used. The fall suppression members 51B and 52B can also be configured using set screws, etc. It is also possible to combine different types of fall suppression members 51B and 52B.

The fixing portion F3 where the tube 31B is fixed to the bracket 20B is composed of fall prevention members 51B and 52B.

Example 4
Next, a fourth embodiment will be described with reference to the drawings.

See Figure 6. The shock absorber 10C of Example 4 has a shock absorber body 30C that is screwed into a bracket 20C. The other basic configuration is the same as that of the shock absorber 10 described above. For components that are the same as those of the shock absorber 10, the same reference numerals will be used and detailed descriptions will be omitted where appropriate.

The lower bracket 22C that constitutes bracket 20C has a female thread formed along the cylindrical hole portion 22Cb.

The outer surface of the upper end of tube 31C is formed with a male thread. The upper end of tube 31C is fastened to cylindrical hole portion 22Cb.

A ring-shaped positioning ring 54C is fixed to the upper end of the cylindrical hole 22Cb to restrict the upward movement of the tube 31C and determine the mounting position of the tube 31C. A ring lid 55C is provided on the inner circumference of the positioning ring 54C to prevent water droplets and other contaminants from entering the interior. The positioning ring 54C and ring lid 55C may be welded to the bracket 20C.

The fixing portion F4 where the tube 31C is fixed to the bracket 20C is formed by screwing the tube 31C to the bracket 20C.

Example 5
Next, a fifth embodiment will be described with reference to the drawings.

See Figure 7. The shock absorber 10D of Example 5 has a configuration in which the shock absorber body 30 is adhered to the bracket 20 with an adhesive. The other basic configuration is the same as the shock absorber 10 described above. For components that are common to the shock absorber 10, the same reference numerals will be used and detailed descriptions will be omitted where appropriate.

The shock absorber 10D is manufactured by applying adhesive to the outer peripheral surface of the lid 32, press-fitting it into the upper end of the tube 31, and then applying adhesive to the outer peripheral surface near the upper end of the tube 31 and press-fitting it into the cylindrical hole 22b. In other words, it is manufactured through an adhesive application process and a press-fitting process.

The fixing portion F5 where the tube 31 is fixed to the bracket 20 is formed by adhesively bonding the tube 31 to the bracket 20.

The shock absorber 10 described above is summarized below.

Refer to Figure 2. First, the shock absorber 10 has a bracket 20 with a cylindrical hole 22b, which is a cylindrical hole, and a cylindrical tube 31 that is supported by the bracket 20 and extends downward from the cylindrical hole 22b. The fixing portion F1 where the tube 31 is fixed to the bracket 20 is formed in a position that avoids the lower end of the bracket 20.

A large load is placed on the lower end of the portion of the bracket 20 where the tube 31 is inserted. The fixing portion F1 is located to avoid this portion of the bracket where a large load is placed. This reduces the load on the fixing portion F1. The same applies to shock absorbers 10A, 10B, 10C, and 10D (see Figures 4 to 7).

Secondly, in the first shock absorber 10, the fixing portion F1 is formed by welding the upper end of the tube 31 to the bracket 20. This allows the tube 31 to be fixed to the bracket 20 with high strength. In addition, the bead fills the gap between the tube 31 and the bracket 20, preventing water from entering. The same applies to shock absorber 10A (see Figure 4).

Thirdly, in the second shock absorber 10, the upper end of the tube 31 is located on approximately the same plane as the upper surface of the bracket 20. Various welding methods, such as laser welding, can be used, which is preferable.

Fourth, the third shock absorber 10 further includes a lid 32 that closes the upper end of the tube 31, and the upper surface of the lid 32 is positioned approximately flush with the upper surface of the bracket 20. The bracket 20, tube 31, and lid 32 can be positioned nearby and easily welded together.

See Figure 5. Fifth, in any of the first to fourth shock absorbers 10B, the fixing portion F3 is configured with a fall-prevention member 51B that is inserted from the bracket 20B to the tube 31B and prevents the tube 31B from falling from the bracket 20B. The portion where the fall-prevention member 51B is inserted does not experience distortion due to heat that can occur during welding.

See Figure 6. Sixth, in any of the first to fifth shock absorbers 10C, the fixing portion F4 is formed by screwing the tube 31C to the bracket 20C. This simplifies the attachment of the tube 31C to the bracket 20C, and prevents distortion at the screwed portion due to heat that can occur during welding.

See Figure 7. Seventh, in any of the first to sixth shock absorbers 10D, the fixing portion F5 is configured by bonding the tube 31 to the bracket 20. This simplifies the attachment of the tube 31 to the bracket 20, and prevents distortion at the bonded portion due to heat that can occur during welding.

See Figure 3. Eighth, in a method for manufacturing a shock absorber for manufacturing any of the first to fourth shock absorbers 10, the tube insertion process for inserting the tube 31 into the cylindrical hole portion 22b is performed by press-fitting. Since there is no need for splitting or threading, the manufacturing cost of the shock absorber 10 can be reduced. The same applies to shock absorbers 10A, 10B, and 10D.

Ninth, in the shock absorber manufacturing method for manufacturing any of the first to fourth shock absorbers 10 or the eighth shock absorber manufacturing method, the welding process for welding the tube 31 to the bracket 20 is performed by laser welding. By using laser welding, the welding process can be completed in a short time, and the shock absorber 10 can be manufactured in a short time. The same applies to shock absorbers 10B and 10D.

Tenth, in the ninth shock absorber manufacturing method, the welding process is performed around the entire circumference of the upper end of the tube 31. This prevents water from entering between the bracket 20 and the tube 31.

Eleventh, any one of the first to seventh shock absorbers 10 is a front fork that is connected to the front wheel of a saddle-ride type vehicle.

Although the shock absorber according to the present invention has been described as being mounted on a front fork, it can also be applied to a rear cushion and is not limited to these types. In other words, as long as the functions and effects of the present invention are achieved, the present invention is not limited to the examples.

The shock absorber of the present invention is suitable for front forks.

10, 10A, 10B, 10C, 10D... Shock absorber 20, 20B, 20C... Bracket 22b, 22Cb... Shock absorber main body insertion hole portion (cylindrical hole portion)
31, 31A, 31B, 31C...tube 32, 32A...lid F1, F2, F3, F4, F5...fixing part

Claims (11)

A bracket with a cylindrical hole,
a cylindrical tube supported by the bracket and extending downward from the cylindrical hole,
A shock absorber, wherein a fixing portion where the tube is fixed to the bracket is formed at a position that avoids a lower end of the bracket. The shock absorber according to claim 1, wherein the fixing portion is formed by welding the upper end of the tube to the bracket. The shock absorber of claim 2, wherein the upper end of the tube is positioned approximately flush with the upper surface of the bracket. The tube further has a lid that closes the upper end thereof,
The shock absorber according to claim 3 , wherein an upper surface of the cover is positioned substantially flush with an upper surface of the bracket. The shock absorber of claim 1, wherein the fixing portion is configured as a fall prevention member that is inserted from the bracket to the tube and prevents the tube from falling from the bracket. The shock absorber according to claim 1, wherein the fixing portion is formed by screwing the tube to the bracket. The shock absorber according to claim 1, wherein the fixing portion is formed by adhering the tube to the bracket. A method for manufacturing the shock absorber according to claim 3, comprising the steps of:
The tube insertion step of inserting the tube into the cylindrical hole is performed by press-fitting. A method for manufacturing the shock absorber according to claim 3, comprising the steps of:
The welding step of welding the tube to the bracket is performed by laser welding. The method for manufacturing a shock absorber described in claim 9, wherein the welding process is performed around the entire circumference of the upper end of the tube. The shock absorber described in claim 1 is a front fork that is connected to the front wheel of a saddle-ride type vehicle.