TWI583593B - Front fork and front fork - Google Patents

Description

Front fork arm and front fork

The present invention relates to a bicycle component, and more particularly to a front fork arm and a front fork.

Referring to Figures 1 and 2, a prior front fork 10 generally includes a standpipe 1 and two front fork arms 2. The front fork arms 2 are respectively disposed on opposite sides of the standpipe 1, and are respectively a combination of a wishbone 21 and a hook member 22 that are assembled together. Each wishbone 21 is hollow tubular and includes a first end 211 welded to the riser 1 and a second end 212 opposite the first end 211. Each of the hook members 22 includes a plunger portion 221 that is plugged to the second end portion 212 of each of the wishbones 21, and a through hole 222 that is formed by an end portion of an axle (not shown). The card portion 223 and the hook members 22 are fixed to the second end portion 212 of each of the wishbones 21 by welding.

However, the wishbone 21 and the claw member 22 of the front fork arm 2 are assembled by welding, and therefore the welding tolerances of the fork bone 21 and the claw member 22 of the front fork arm 2 after welding are assembled, and After the structural deformation tolerance of the front fork arm 2 through the heat treatment, the accuracy of the parallelism and concentricity of the insertion holes 222 of the front fork arms 2 assembled to the vertical pipe 1 is increased, and the accuracy tolerance cannot be increased. The problem of assembly of the axle and the welding technique are different. Further, the hook member 22 is inserted into the wishbone 21 through the plunger portion 221 being plugged to the second end portion 212 of the wishbone 21, so that the front portion The fork 10 is used for a bicycle and when riding, it is easy to put a considerable force on the joint of the claw member 22 and the wishbone 21, so that the welded portion formed between the claw member 22 and the wishbone 21 is easily broken due to poor welding. Even a gap is created between the hook member 22 and the wishbone 21, thereby affecting the handling and safety during riding.

Furthermore, the shape of the plug portion 221 of the hook member 22 must match the shape of the second end portion 212 of the wishbone 21 to achieve a tightly engaging effect, and thus for the wishbone 21 having different shape changes. Then, different molds are needed to mold and manufacture the corresponding claw members 22, thereby increasing the mold manufacturing cost, and the vertical tube 1, the wishbone 21 and the claw members 22 of the front fork 10 are separately assembled and then assembled together. The production process of the front fork 10 described above is complicated.

Accordingly, it is an object of the present invention to provide a front fork arm that is integrally formed and has high structural strength.

Thus, the front fork arm of the present invention includes a straight arm section that is tubular and extends along a straight line, and a front fork card that extends outwardly along the straight line from one end of the straight arm section, the straight arm section The end portion corresponding to the front fork card is closed, and the straight arm segment and the front fork card are integrally formed of aluminum.

The effect of the invention is that the front fork arm of the invention has the effect of high structural strength due to the integrally formed seamless structure, and can be used for the bicycle and is capable of withstanding a considerable force impact while riding. Integrity to maintain good handling and safety during riding.

therefore. Another object of the present invention is to provide a front fork having an integrally formed and high structural strength front fork arm, thereby reducing the number of component parts to avoid the problem of poor precision due to accumulation of assembly tolerances.

Thus, the front fork of the present invention comprises a standpipe and two front fork arms.

The front fork arms are respectively disposed on opposite sides of the vertical tube, and each front fork arm includes a bent arm section connected to the tubular shape and a straight arm section extending along a straight line, and a reversed straight arm section a front fork card extending outward along the straight line at an end of the curved arm segment, the curved arm segment being connected to the riser opposite to an end of the straight arm segment, the straight arm segment being opposite to the curved arm The end portion of the segment is closed, and the front fork card of each front fork arm has a through portion, and the curved arm segment, the straight arm segment and the front fork card are integrally formed of aluminum.

The effect of the invention is that the front fork arm of the front fork of the invention is not only capable of achieving high structural strength due to the integrally formed seamless structure, but is capable of withstanding considerable force when used on a bicycle and when riding. The impact maintains the integrity of the structure, maintains good handling and safety during riding, and also reduces the number of assembled parts to avoid the problem of poor precision due to the accumulation of assembly tolerances.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 3 and 4, an embodiment of the front fork arm of the present invention is produced by the following manufacturing steps:

In a step 71, a metal pipe 3 is piped and expanded by a pipe processing machine (not shown) to be processed into a preformed pipe member 4 having a predetermined length and a wall thickness variation, and the preformed pipe member 4 is along a straight line L. The first end portion 41 and the second end portion 42 are oppositely disposed, wherein the first end portion 41 has a tube wall thickness T1, and the second end portion 42 has a tube wall thickness. For T2, the wall thickness of the portion connected between the first end portion 41 and the second end portion 42 is T3, and the preformed tubular member 4 satisfies the following wall thickness variation: T1 ≧ 1.5 * T2, T2 > T3 In this embodiment, the metal pipe 3 is made of an aluminum alloy;

Step 72: Following the step 71, the preformed tubular member 4 is subjected to cold forging processing to press-close the first end portion 41 to form a straight pipe section 411 extending along the straight line L and having a substantially tapered shape. And a solid cylinder 412 extending outward from the straight end of the straight pipe section 411 away from the second end portion 42. That is, the straight pipe section 411 and the solid cylinder 412 are integrally formed by cold forging. to make;

a step 73: after the step 72, the preformed tubular member 4 is shaped, thereby pressing the solid cylinder 412 into a front fork card 414;

Step 74: Following the step 73, the straight pipe section 411 is press-formed into a hollow straight arm section 413, and the portion of the preformed pipe member 4 located at the second end portion 42 to the straight pipe section 413 is bent. And pressing and molding into a curved arm section 415, that is, completing the manufacture of the integrally formed front fork arm 4', wherein the straight arm section 413 and the front fork card 414 are integrated by the cold metal forging by the metal pipe member 3. It is then pressed and molded.

That is, the front fork arm 4' of the present invention is the curved arm section 415 including the above-mentioned connected and respectively tubular and the straight arm section 413 extending along the straight line L, and the straight arm section 413 is opposite to the curved section The end of the arm section 415 extends outward along the line L and is a solid front fork card 414. The straight arm section 413 is closed opposite to the end of the curved arm section 415. The curved arm section 415 is straight. The arm section 413 and the front fork card 414 are integrally formed of an aluminum alloy.

It is to be noted that the step 73 and the step 74 in the manufacturing step of the embodiment of the front fork arm of the present invention can also mold only the preformed tubular member 4 into the above-described integrally formed straight arm segment 413 and The fork plate 414, however, is partially cast as a separate component or part of a standpipe formed as a front fork, which is then welded to the straight arm section 413 during subsequent assembly. That is to say, this embodiment of the front fork arm of the present invention may also include only the straight arm section 413 and the front fork card 414 which are integrally formed as described above.

Preferably, the manufacturing step of the embodiment of the front fork arm of the present invention may further comprise a step 75: following the step 74, with reference to FIG. 5, the front fork of the front fork arm 4' is processed by CNC machining. The card 414 is subjected to a final shaping process to form a through portion 416 for the end of one of the axles (not shown). The through portion 416 is a through hole provided through the through hole. It is the production of the barrel-type front fork arm 4'. It is to be noted that the front fork card 414 of the front fork arm 4 ′ can be subjected to final shaping to form the through portion 416 , and the through portion 416 is not formed by the through hole. Alternatively, it may be a notch (see FIG. 6) which is recessed inward by the end edge of the forearm section 413, and the finished front fork arm 4' is open.

It is added here that the reason why the wall thicknesses T1 and T2 of the first end portion 41 and the second end portion 42 of the preformed tubular member 4 obtained in the above step 71 need to satisfy T1 ≧ 1.5*T2 is as follows: The first end portion 41 of the preformed tubular member 4 is cold forged into the solid cylinder 412 having a sufficient volume at step 72, so that the solid cylinder 412 can be press-formed to have a sufficient thickness and plate in step 73. The front fork card 414 of the area enables the front fork card 414 to achieve good structural strength.

In summary, the front fork arm of the present invention is directly formed by a metal pipe 3 through a pipe drawing, cold forging and shaping step to obtain an integrally formed and high structural strength front fork arm 4', compared with the conventional two pieces. The method of the combined front fork arm eliminates the individual manufacturing process of the wishbone and the claw piece and the process of assembling and welding the two, and does not need to use different molds for forming the manufacturing phase of the wishbone having different shape changes. Corresponding hook parts, thereby eliminating the relative mold manufacturing cost, and the front fork arm of the present invention is a one-piece jointless structure, thereby achieving high structural strength, can be used in bicycles and when riding It is sufficient to withstand considerable force impact and maintain the integrity of the structure to maintain good handling and safety during riding, so it is indeed possible to achieve the object of the present invention.

Referring to Figures 7 and 8, an embodiment of the front fork of the present invention is produced by the following manufacturing steps:

a step 81: providing a vertical tube 5 made of metal, and a front fork arm 4' which is integrally formed through steps 71 to 74 (see FIG. 4) of the method for manufacturing the front fork arm, and The front fork arm 4' is welded to the standpipe 5, and the weld bead 6 formed between the standpipe 5 and the front fork arms 4' is smoothed, wherein the front fork arms 4' are located at the vertical The opposite sides of the tube 5, and the front fork arms 4' are connected to the vertical tube 5 opposite to the end of the front fork card 414. In the present embodiment, the vertical tube 5 and the front fork arms 4 The material of the material is aluminum alloy. It is added that the front fork arm 4' which is integrally formed through the steps 71 to 74 of the method for manufacturing the front fork arm may also have only the forearm segment 413 and the The front fork card 414, and the curved arm section 415 is additionally cast and then welded between the standpipe 5 and the forearm section 413, or the standpipe 5 is integrally formed with two curved arm sections 415, and The forearm segments 413 of the front fork arms 4' are respectively bent arms that weld the vertical tubes 5;

Step 82: Following the step 81, the vertical tube 5 and the front fork arms 4' welded together are heat-treated, so that the vertical tube 5 and the front fork arms 4' reach predetermined metal physical properties. In this embodiment, the heat treatment step is mainly for increasing the metal strength of the standpipe 5 and the front fork arms 4';

Step 83: Following the step 82, with reference to FIG. 5, the front fork card 414 of each front fork arm 4' is subjected to final machining in a CNC machining manner, thereby forming an available axle (not shown). One end portion is provided with a fastening through portion 416 which is a through hole which is formed through a through hole, that is, a front fork having a cylindrical shaft type front fork arm 4' is completed. It should be noted that the wearing portion 416 is also not limited to the above-mentioned through hole, and may be a notch (see FIG. 6) which is recessed inward from the end edge of the forearm segment 413, and is completed. The front fork arm 4' of the front fork is open.

That is, the embodiment of the front fork of the present invention comprises the vertical tube 5 and the front fork arms 4', and the front fork arms 4' are respectively disposed on opposite sides of the vertical tube 5, each front fork The arm 4' includes the curved arm section 415 which is connected and respectively tubular, and the straight arm section 413 extending along the straight line L, and the straight arm section 413 is opposite to the end of the curved arm section 415 along the straight line L An outwardly extending front fork card 414, the curved arm section 415 being coupled to the riser 5 opposite the end of the straight arm section 413, the straight arm section 413 being closed opposite to the end of the curved arm section 415 The front fork card 414 of each front fork arm 4' has the through portion 416. The curved arm portion 415, the straight arm portion 413 and the front fork card 414 are integrally formed of an aluminum alloy.

In summary, the front fork of the present invention is an assembly and welding of the integrally formed and high structural strength front fork arm 4' obtained by the metal pipe 3 through the pipe drawing, cold forging and molding steps. After the heat treatment step, the through portions 416 of the front fork arms 4' are formed such that the parallelism, concentricity, etc. of the through portions 416 of the front fork arms 4' of the front fork of the present invention are combined with an axle The assembly accuracy is not affected by the welding tolerance between the front fork arm 4' and the vertical tube 5 and the structural deformation tolerance after the heat treatment, and the front fork of the present invention is compared with the conventional front fork, and the fork is omitted. The individual manufacturing process of the bone and the claw member and the steps of assembling and welding the two, and it is not necessary to use different molds for forming the corresponding claws for the wishbone having different shape changes, thereby eliminating the relative mold. The manufacturing cost, and the front fork arm 4' of the front fork of the invention is an integrally formed seamless structure, thereby achieving high structural strength, and can be used for a bicycle and is capable of withstanding considerable force when riding. Impact and maintain the integrity of the structure, dimension Good handling and safety, it can really achieve the objective of the present invention while riding.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still The scope of the invention is covered.

<TABLE border="1" borderColor="#000000" width="_0001"><TBODY><tr><td> 3·········· Metal pipe 4········ · Preformed pipe fittings 41········ The first end part 411······ Straight pipe section 412······ Solid cylinder 413······ Straight arm section 414·· ···· Front fork card 415······ Bending arm section 416······ The wearing part 42········ The second end part 4'······· ·· Front Fork Arm 5·········· Standpipe 6·········· Welded </td><td> T1········ Wall thickness T2········ Wall thickness T3········ Tube wall thickness L··································································· ····· Step 73········ Step 74········ Step 75 ··················································· ···· Step 83········ Steps</td></tr></TBODY></TABLE>

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will be apparent from the embodiments of the present invention, wherein: Figure 1 is a perspective view of a conventional front fork; Figure 2 is a partially enlarged cross-sectional view of a conventional front fork, illustrating The two front fork arms of the front fork are respectively a combined design of a hook member inserted into one end of a wishbone; FIG. 3 is a side view of an embodiment of the front fork arm of the present invention; FIG. 4 is a view of the embodiment. A schematic plan view of a manufacturing process for forming a metal pipe through each step to form an integrally formed front fork arm; FIG. 5 is a side view of a cylindrical front fork arm of the embodiment; FIG. Figure 7 is a side elevational view of an embodiment of the front fork of the present invention; and Figure 8 is a plan view of a manufacturing flow of the embodiment, illustrating a metal riser And the two-in-one front fork arm is formed into a front fork through each step.

<TABLE border="1" borderColor="#000000" width="_0002"><TBODY><tr><td> 413······ Straight arm section 414······ Front fork card 415 ······ Bending arm section </td><td> 416························································································· · Line </td></tr></TBODY></TABLE>

Claims (6)

A front fork arm includes a straight arm section that is tubular and extends along a straight line, and a front fork card that extends outward along the straight line from one end of the straight arm section, the straight arm section corresponding to The end portion of the front fork card is closed, and the straight arm segment and the front fork card are integrally formed by cold forging aluminum. The front fork card and the straight arm segment are made of a metal pipe. The pipe is processed into a first end portion of a preformed pipe member having a predetermined length and a wall thickness variation and having oppositely disposed first end portions and a second end portion, and is integrally formed by cold forging and sealing. The wall thickness of the first end portion is not less than 1.5 times the thickness of the tube wall of the second end portion. The front fork arm of claim 1, wherein the front fork card includes a notch recessed inwardly from an end edge of the straight arm segment. The front fork arm of claim 1, wherein the front fork card includes a through hole disposed therethrough. A front fork includes: a vertical tube; and two front fork arms respectively disposed on opposite sides of the vertical tube, each front fork arm including a bent arm section connected and respectively tubular and a straight line extending along a straight line An arm segment, and a front fork card extending outwardly from the end of the straight arm segment opposite the curved arm segment, the curved arm segment being opposite to the riser segment at an end of the straight arm segment Connecting, the straight arm segment is closed opposite to the end of the curved arm segment, and the front fork card of each front fork arm has a through portion, the curved arm segment, the straight arm segment and the front fork card are Aluminum cold forging integrated, the front fork card and the straight arm segment are processed by a metal pipe to have a predetermined a first end portion of the preformed tubular member having a length and a wall thickness variation and having oppositely disposed first end portions and a second end portion, integrally formed by cold forging and sealing, the first end portion being The wall thickness is not less than 1.5 times the thickness of the tube wall of the second end. The front fork according to claim 4, wherein the through portion of each front fork card is a notch recessed inwardly from an end edge of the straight arm portion. The front fork according to claim 4, wherein the through portion of each front fork card is a through hole that is disposed through.