JP2009255874A - Method of manufacturing bracket for front fork, method of manufacturing structure with lid, bracket for front fork and structure with lid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a bracket for front forks capable of integrating a bracket body and a lid member without spoiling a fine appearance. <P>SOLUTION: The method of manufacturing a bracket for front forks includes a preparation step for providing a lid member 3 so as to cover a recess portion recessed in one face of a fabricated material 2 that is a base material of a bracket body, a friction-stirring joining step for relatively moving a rotation tool T for friction-stir joining along a friction-stirring route set to include a borderline P between an open edge part of the recess portion of the fabricated material 2 and a periphery part of the lid member 3, and a hole formation step for forming fork attachment holes and a steering shaft insertion hole 12 penetrating through the bracket body. In the friction stir joining step, the friction stir is terminated with a finishing allowance 22s of the steering shaft insertion hole 12. In the hole formation step, the finishing allowance 22s is removed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a front fork bracket and a manufacturing method thereof, and a structure with a lid and a manufacturing method thereof.

  As a front fork bracket for a bar handle vehicle, one disclosed in Patent Document 1 is known. The front fork bracket includes a pair of left and right boss portions (slit fastening portions) and a bridge portion that connects both boss portions.

  By the way, although the bracket for front forks of patent document 1 has aimed at weight reduction by making a bridge part into a rib structure, since a crevice etc. formed with a rib are exposed, there is a possibility of spoiling beauty.

  Such a problem can be solved by joining a lid member (decorative member) that covers the recess. In addition, a cover member can be integrated by performing friction stir welding along the boundary line of the peripheral part and the opening edge part of a recessed part (for example, refer patent document 2).

Japanese Patent Laying-Open No. 2007-302109 (FIG. 4) Japanese Patent No. 3409673

  If friction stir welding is used, the lid can be joined easily and quickly. However, when the rotary tool is removed, a hole substantially in the same shape as the probe (stirring pin) is inevitably formed. Therefore, when the end position of the friction stir welding is provided in the final product, the aesthetic appearance may be impaired. Such a problem is common not only when manufacturing a structure with a lid formed by covering a lid member on a base member having a recess or an opening by friction stir welding as well as a front fork bracket. It is a problem that applies.

  From such a viewpoint, the present invention is a method for manufacturing a front fork bracket in which a lid member is covered on a bracket body having a recess or an opening, and the bracket body and the lid member are integrated without impairing the appearance. It is an object of the present invention to provide a method for manufacturing a front fork bracket that can be reduced in size, and further to a method for manufacturing a lidded structure that covers a base member having a recess or an opening. Therefore, an object of the present invention is to provide a method for manufacturing a lidded structure capable of integrating the base member and the lid member without impairing the beauty. In addition, an object of the present invention is to provide a front fork bracket and a lidded structure having a good aesthetic appearance.

  A manufacturing method of a front fork bracket according to the present invention that solves such a problem includes a preparation step of covering a lid member on a bottomed recess recessed in one surface of a raw material of a bracket body; A friction stir welding step of relatively moving the rotary tool for friction stir welding along the friction stir route set to include a boundary line between the opening edge of the bottomed recess and the peripheral edge of the lid member; A fork mounting hole for penetrating the bracket body and a hole forming step for forming a steering shaft insertion hole, wherein the fork mounting hole or the steering shaft is formed in the friction stir welding step. Friction stirring is finished at the finishing allowance of the insertion hole, and the hole forming step is performed to remove the finishing allowance.

  In short, the present invention is characterized in that the rotary tool is detached at the finishing allowance of the fork mounting hole or the steering shaft insertion hole (the part removed in the hole forming process). In this way, it is possible to eliminate the trace of the punched hole of the rotary tool despite the fact that the end position of the friction stirrer is provided in the shaped material, so that the shape material can be obtained without impairing the appearance. The lid member can be integrated. In addition, since the bracket for front forks manufactured by the manufacturing method of this invention comprises the closed space formed by closing a bottomed recessed part with a cover member, it is lightweight, but its rigidity is high.

  The fork mounting hole or the steering shaft insertion hole is recessed in the other surface of the base material, and in the friction stir welding step, friction stir is performed at the bottom wall of the pilot hole serving as the finishing allowance. It is good to finish. If it does in this way, it will become possible to reduce the burden concerning the tool for finishing.

  In the friction stir welding step, it is preferable to start friction stirring from the finishing allowance. In this way, even if an initial failure or the like occurs at the friction stirring start position, it is removed when the fork mounting hole or the steering shaft insertion hole is formed, so that a high-quality front fork bracket is obtained. It becomes possible.

  In addition, it is desirable that the route for friction stirring includes an annular route provided so as to surround the lid member. If it does in this way, since friction stir welding will be performed over the perimeter of a cover member, it will become possible to prevent permeation of water etc. in closed space.

  In addition, if the start and end portions of the annular route are overlapped, the closed space can be reliably sealed, so that intrusion of water or the like into the closed space can be more reliably prevented. It becomes.

  In another method for manufacturing a front fork bracket according to the present invention that solves the above-described problems, a first lid member is covered on one opening end of an opening formed in a base material that is a base of a bracket body. Relative movement of the rotary tool for friction stir welding along the friction stir route set to include the first preparation step and the boundary line between the opening edge of the opening and the peripheral edge of the first lid member A first surface side friction stir welding step, a second preparatory step of covering a second lid member on the other opening end of the opening, an opening edge of the opening and a peripheral edge of the second lid member The other surface side friction stir welding step for relatively moving the friction stir welding rotary tool along the friction stir route set to include the boundary line, and the hole forming step for forming the fork mounting hole and the steering shaft insertion hole And including front In the one side friction stir welding step and the other side friction stir welding step, friction stirring is terminated at the finishing allowance of the fork mounting hole or the steering shaft insertion hole, respectively. In the hole forming step, processing for removing the finishing allowance is performed.

  In this way, it is possible to eliminate the trace of the punched hole of the rotary tool despite the fact that the end position of the friction stirrer is provided in the shaped material, so that the shape material can be obtained without impairing the appearance. The lid member can be integrated. Note that the front fork bracket manufactured by the manufacturing method of the present invention includes a closed space formed by closing the opening end of the opening portion with the first lid member and the second lid member, and thus is lightweight. Although it is, it has high rigidity.

  The method for manufacturing a lidded structure according to the present invention for solving the above-described problem includes a preparation step of covering a lid member on a bottomed recess or an opening formed in a base material of a base member, Relative movement of the rotary tool for friction stir welding along the friction stir route set to include the opening edge of the bottomed recess or the boundary between the opening edge of the opening and the peripheral edge of the lid member And a hole forming step for forming a through-hole in the base member. In the friction stir welding step, in the friction stir welding step, friction agitation is performed at a finishing allowance of the through-hole. And in the hole forming step, processing for removing the finishing allowance is performed.

  In this way, it is possible to eliminate the trace of the punched hole of the rotary tool despite the fact that the end position of the friction stirrer is provided in the shaped material, so that the shape material can be obtained without impairing the appearance. The lid member can be integrated. In addition, there is no restriction | limiting in the use of a structure with a lid | cover, It can use as parts for vehicles, parts for construction, a closed container, etc. Moreover, there is no restriction | limiting also in the use purpose of a through-hole.

  A bracket for a front fork according to the present invention that solves the above-described problem includes a bracket body having a recess or an opening, and a lid member that covers the recess or the opening, and an opening edge of the recess Alternatively, a front fork bracket in which the opening edge of the opening and the peripheral edge of the lid member are friction stir welded, the bracket body having a fork mounting hole and a steering shaft insertion hole, the fork mounting hole At least one of the steering shaft insertion hole is formed in a portion including the end position of the friction stirring.

  With the front fork bracket having such a configuration, the trace of the punched hole of the rotary tool becomes inconspicuous, and the aesthetics are good. In addition, although there is no restriction | limiting in the material and manufacturing method of the said bracket main body, It is desirable that it is a cast or forged product made from an aluminum alloy. If the bracket body is a cast product or a forged product, it is possible to easily form a recess or the like. The cast product or forged product includes an aluminum alloy member formed by forging after casting.

  In addition, a lidded structure according to the present invention that solves the above-described problem includes a base member having a recess or an opening, and a lid member that covers the recess or the opening, and the opening of the recess An edge or an opening edge of the opening and a peripheral portion of the lid member are friction stir welded, wherein the base member has a through hole, and the through hole is friction stir It is formed in the site | part containing the ending position of.

  With the lidded structure having such a configuration, the trace of the punched hole of the rotary tool becomes inconspicuous, and the aesthetics are good.

  According to the method for manufacturing a front fork bracket according to the present invention, it is possible to easily form the hollow portion of the closed space, so that the weight can be reduced, and the steering shaft insertion hole and the fork are provided. Since the end position of the friction stir welding is provided at the finishing allowance of the mounting hole, it is possible to obtain a front fork bracket having a good appearance.

  According to the manufacturing method of the lidded structure according to the present invention, it is possible to reduce the weight thereof, and the end position of the friction stir welding is provided in the finishing allowance of the through hole. A lidded structure can be obtained.

  In addition, according to the front fork bracket and the lid-attached structure according to the present invention, the trace of the punched hole of the rotary tool becomes inconspicuous, so that the aesthetics are good.

  As shown in FIG. 9, a front fork bracket B according to an embodiment of the present invention connects a pair of left and right front forks F, F and is a hollow component (with a lid) that supports a steering shaft (not shown). Structure). Incidentally, the front fork F supports the front wheel W of the bar handle vehicle, and the steering shaft is rotatably inserted into the head pipe. In the following, a case where the front fork bracket B is the under bracket B will be exemplified, but this is not intended to exclude application to the upper bracket B 'for connecting the upper ends of the front forks F, F to each other.

  As shown in FIG. 1, the front fork bracket B (hereinafter simply referred to as “bracket B”) includes a bracket body 1 and lid members 3 and 3 joined to the bracket body 1.

  1 to 5 show a state in which the lid member 3 is on the upper side. In the following description, the upper surface in the illustrated state is “one surface” and the lower surface is “other surface”. However, this is for convenience and does not always coincide with which one is used as the upper side in the actual use state.

  The bracket body 1 includes a pair of fork attachment holes 11 and 11 provided at both ends in the longitudinal direction, a steering shaft insertion hole 12 provided between the fork attachment holes 11 and 11, and the steering shaft insertion hole. 12 (see FIG. 1C), a slit 14 extending from the outer peripheral surface of the bracket body 1 to the fork mounting hole 11, and a fastening formed so as to straddle the slit 14 Attached hole 15 is provided. That is, the bracket main body 1 includes a side boss 1a, 1a that is a hole wall of the fork attachment hole 11, a center boss 1b that is a hole wall of the steering shaft insertion hole 12, and a web that connects the left and right side bosses 1a, 1a and the center boss 1b. 1c (see FIG. 1C) and ribs 1d, 1d,... Erected on the web 1c.

  The fork attachment hole 11 and the steering shaft insertion hole 12 are through holes that penetrate the bracket body 1 in the vertical direction. A front fork F (see FIG. 9) is inserted into the fork mounting hole 11, and a steering shaft (not shown) is inserted into the steering shaft insertion hole 12.

  As shown in FIG. 1 (b), the tightening hole 15 is a stepped hole provided so as to intersect with the slit 14, and a counterbore 15a recessed in the side surface of the side boss 1a and a counterbore portion 15a. And a female screw 15b formed from the bottom toward the recess 13 (see FIG. 1C). Note that a fastening screw (not shown) for reducing the diameter of the fork mounting hole 11 is screwed into the female screw 15b.

  The bracket main body 1 is formed using a base material 2 shown in FIG. The base material 2 is a member that is a base of the bracket body 1, and the one in the present embodiment is made of an aluminum alloy casting, a forging, or an aluminum alloy member that is forged after casting.

  The base material 2 is formed to have substantially the same outer shape as the bracket body 1, and has a mounting hole pilot hole 21 that is a pilot hole of the fork mounting hole 11 and an insertion hole that is a pilot hole of the steering shaft insertion hole 12. The bottom hole 22 and the bottomed recessed part 23 used as the recessed part 13 (refer FIG. 1) are provided.

  The mounting hole pilot hole 21 is a bottomed hole formed inside the region to be the fork mounting hole 11, and is formed coaxially with the fork mounting hole 11, but the raw material 2 is cast or forged. Therefore, a predetermined draft is provided on the hole wall surface (side surface) of the mounting hole pilot hole 21. As shown in FIG. 2 (c), the mounting hole pilot hole 21 of the present embodiment includes one recessed on one surface of the shaped member 2 and one recessed on the other surface. In other words, in the present embodiment, two fork holes 21 and 21 for mounting holes are formed for each fork mounting hole 11.

  The diameter of the mounting hole pilot hole 21 is smaller than that of the fork mounting hole 11, and the mounting hole finishing allowance 21s (see FIGS. 2B and 2C) is provided around the mounting hole pilot hole 21. The part marked with light ink is secured. The mounting hole finishing allowance 21s is a part that is removed when the fork mounting hole 11 is formed, and is a cylindrical portion 21a that serves as a hole wall (side wall) of the mounting hole lower hole 21 and a plan view that serves as a bottom wall. It consists of a circular bottom portion 21b and has an H-shaped cross section. The cylindrical portion 21a has a thickness necessary for forming the fork mounting hole 11 with high dimensional accuracy.

  The insertion hole pilot hole 22 is a bottomed hole formed inside the region to be the steering shaft insertion hole 12 and is formed coaxially with the steering shaft mounting hole 12. Since it is formed at the time of forging, the hole wall surface (side wall surface) is provided with a predetermined draft. The insertion hole pilot hole 22 of the present embodiment is recessed in the other surface of the shaped member 2.

  The diameter of the insertion hole lower hole 22 is smaller than that of the steering shaft insertion hole 12, and the insertion hole finishing allowance 22s (see FIGS. 2B and 2C) is provided around the insertion hole lower hole 22. The part marked with light ink is secured. The insertion hole finishing allowance 22s is a part that is removed when the steering shaft insertion hole 12 is formed, and is a cylindrical portion 22a that becomes a hole wall (side wall) of the insertion hole lower hole 22, and a plane that becomes the bottom wall. It consists of a bottom portion 22b having a circular shape and has an inverted U-shaped cross section. The cylindrical portion 22a has a wall thickness necessary for forming the steering shaft insertion hole 12 with high dimensional accuracy. The bottom portion 22b is a portion that becomes an insertion position or a detachment position of a rotary tool T (see FIG. 5) to be described later, and has a thickness dimension larger than a depth at which plastic fluidization occurs during friction stirring.

  In the present embodiment, the bottomed recess 23 is formed at two locations on the left and right. A mounting surface 23 a parallel to one surface of the shaped member 2 is formed at the open end of the bottomed recess 23 over the entire circumference. The placement surface 23a is formed at a position lower than the thickness of the lid member 3 (see FIG. 2A) from one surface of the raw material 2. Although most of the bottomed recess 23 is formed when casting or forging the shaped material 2, the placement surface 23 a is formed after casting or forging of the shaped material 2. The placement surface 23a can be formed, for example, by performing step processing on one surface of the shaped member 2 using an end mill or the like. In addition, the bottomed recess 23 of the present embodiment is formed with a partition wall 23b that rises from the bottom surface. The partition wall 23b supports the lid member 3, and the upper end surface thereof is flush with the placement surface 23a.

  The lid member 3 shown in FIG. 1 is covered with a recess 13 (see FIG. 1C) of the bracket body 1 and is friction stir welded to the opening edge of the recess 13. As shown in FIG. 2A, the lid member 3 has an outer shape substantially the same as the opening shape of the bottomed concave portion 23 of the base material 2 that is the element of the bracket body 1. The outer peripheral surface faces the hole wall surface at the open end of the bottomed recess 23 with substantially no gap. The material of the lid member 3 is not limited as long as it can be friction stir welded and has a required strength, but in this embodiment, an aluminum alloy is used in accordance with the material of the base material 2.

Next, the manufacturing method of the bracket B will be described in detail.
The manufacturing method according to the present embodiment includes a preparation process, a friction stir welding process, and a hole forming process.

  As shown in FIG. 3, the preparation step is a step of covering the lid member 3 on the bottomed recess 23 of the shaped member 2. In the present embodiment, it is only necessary to place the lid member 3 on the placement surface 23 a of the bottomed recess 23. When the lid member 3 is placed on the placement surface 23a, the surface of the shaped member 2 and the surface of the lid member 3 are flush with each other, and the inner peripheral surface of the bottomed recess 23 and the outer peripheral surface of the lid member 3 are abutted. Will be.

  The friction stir welding step is a step of friction stir welding the opening edge 2a (see FIG. 2A) of the bottomed recess 23 and the peripheral edge 3a of the lid member 3 (see FIG. 2A). . In the friction stir welding process, as shown in FIGS. 4A and 4B, the friction stir set so as to include the boundary line P between the opening edge of the bottomed recess 23 and the peripheral edge of the lid member 3. The friction stir welding is performed by relatively moving the rotary tool T for friction stir welding along the route of. The friction stir welding may be performed by moving the rotary tool T without moving the base material 2 or the like, or the base supporting the base material 2 or the like may be moved without moving the rotary tool T. Friction stir welding may be performed.

  The friction stirring start position (insertion position of the rotary tool T) and end position (removal position of the rotation tool T) in the present embodiment are the central portion C of the bottom portion 22b of the insertion hole finishing allowance 22s (FIG. 5). (Refer to (a) and (b)), the route of friction stirring is a straight route from the central portion C of the finishing allowance 22s for the insertion hole to the one (left side in the present embodiment) lid member 3, and one lid An annular route (a route along the boundary line P) provided so as to surround the member 3, and the other (right side in the present embodiment) from one lid member 3 via the center portion C of the insertion hole finishing allowance 22s. A V-shaped route leading to the lid member 3, an annular route provided so as to surround the other lid member 3, and a linear route extending from the other lid member 3 to the central portion C of the finishing allowance for insertion holes 22s. It consists of. That is, in the friction stir welding process of the present embodiment, as shown in FIG. 5A, the bottom wall (bottom portion 22 b) of the insertion hole pilot hole 22 that opens to the other surface side of the shaped member 2 is formed. The process of inserting the rotary tool T from one side of the raw material 2 and the rotary tool T is moved so as to form a one-stroke drawing movement trajectory (bead) as shown in FIGS. 4 (a) and 4 (b). Then, the process of joining the two left and right lid members 3 and 3 in one step and, as shown in FIG. 5 (b), the rotary tool T is moved upward from the bottom wall (bottom portion 22b) of the insertion hole lower hole 22. The process of withdrawing.

  In the present embodiment, the start end S (see FIG. 4A) and the end E (see FIG. 4B) of the circular route overlap (overlap). Although there is no restriction | limiting in the range (length) to overlap, it is desirable to set it as the shoulder diameter or more of the rotary tool T. FIG.

  The hole forming step is a step of forming the fork attachment holes 11 and 11 and the steering shaft insertion hole 12 as shown in FIG. That is, in the hole forming step, a drill or an end mill is inserted into the mounting hole pilot hole 21 and the insertion hole pilot hole 22 to remove the mounting hole finishing allowance 21s and the insertion hole finishing allowance 22s (for example, cutting). It is a process of performing. Since the mounting hole pilot hole 21 and the insertion hole pilot hole 22 are provided, the load applied to the machining tool is small. In this embodiment, since the friction stirring is terminated at the insertion hole finishing allowance 22s, if the insertion hole finishing allowance 22s is removed, the punch hole H of the rotary tool T is also removed, and the friction stirring is performed. The steering shaft insertion hole 12 is formed at a portion including the end position.

  Thereafter, when the slit 14 and the fastening hole 15 shown in FIG. 1B are formed at appropriate positions of the base material 2, the bracket body 1 shown in FIG. 1 is formed, and the bracket B is completed. In addition, you may perform surface grinding | polishing, surface treatment, etc. as needed.

  According to the method for manufacturing the front fork bracket according to the present embodiment described above, the punch hole of the rotary tool T is provided even though the friction stirring end position is provided in the bracket main body 1 (molded material 2). Since the traces of H can be eliminated, it is possible to integrate the bracket body 1 (original material 2) and the lid member 3 without impairing the beauty.

  Further, in this embodiment, since the friction stirring is started from the insertion hole finishing allowance 22s, even if an initial failure or the like occurs at the friction stirring start position, it is removed when the steering shaft insertion hole 22 is formed. As a result, a high-quality bracket B can be obtained.

  Moreover, according to this embodiment, since friction stir welding is performed over the perimeter of the cover member 3, it becomes possible to prevent the penetration | invasion of the water etc. to the hollow part of the bracket B. FIG. In addition, in the present embodiment, since the start end S and the end E of the annular route are overlapped, the water tightness of the joining portion is increased, and as a result, the intrusion of water or the like into the hollow portion is more reliably prevented. It becomes possible.

  Moreover, since the bracket B obtained by the manufacturing method according to the present embodiment includes a closed space formed by closing the recess 13 of the bracket body 1 with the lid member 3, the bracket B is lightweight but rigid. high. In addition, according to the bracket B, the trace of the punched hole H of the rotary tool T becomes inconspicuous, so that the aesthetic appearance becomes good. The bracket B is formed with a concave portion 13 for weight reduction. However, since the concave portion 13 is covered with the lid member 3, the concave portion 13 is provided even when the steering shaft is largely inclined. Is not exposed, and thus the bracket B having a good appearance can be obtained.

The procedure of the manufacturing method, the configuration of the raw material 2 and the like may be changed as appropriate.
For example, in the friction stir welding process of the above-described embodiment, the case where the left and right lid members 3 and 3 are joined in one process by moving the rotary tool T so as to form a one-stroke writing trajectory (bead) is illustrated. However, as shown in FIG. 6A, it is of course possible to join in two steps.

  In the above-described embodiment, the case where the start position and the end position of the friction stirrer are matched is illustrated, but the start position and the end position of the friction stirrer may be different. Further, if the trace of the friction stirring start position is not conspicuous, the friction stirring start position may be set at a portion other than the mounting hole finishing allowance 21s and the insertion hole finishing allowance 22s.

  In the above-described embodiment, when friction stirring is performed along the annular route (route along the boundary line P), the start end S and the end E are overlapped within a range of several times the shoulder diameter of the rotary tool T. However, as shown in FIG. 6A, the rotation tool T may be overlapped within the range of the shoulder diameter.

  In the embodiment described above, the case where the insertion hole pilot hole 22 is a bottomed hole is illustrated, but it may be a through-hole penetrating vertically as in the shaped member 2 shown in FIG. In this case, the finishing allowance 22s for the insertion hole is only the cylindrical part that becomes the hole wall of the lower hole 22 for the insertion hole. Therefore, the points C1 and C2 provided in the cylindrical part are set to the rotary tool T (FIG. 6). (A)) may be set as the insertion position or the detachment position. In addition, when forming the through hole pilot hole 22 during the casting process or the forging process of the raw material 2, the through hole pilot hole 22 has a truncated cone shape due to the draft angle, The opening diameter is also different between the front and back of the shaped member 2. That is, the wall thickness of the insertion hole finishing allowance 22s is different between the one surface side and the other surface side of the shaped member 2. In order to secure the insertion position and the removal position of the rotary tool T in the cylindrical portion of the insertion hole finishing allowance 22s, it is necessary to set the thickness of the cylindrical portion to be larger than the shoulder diameter of the rotary tool T. Insertion is made so that the inner diameter of the insertion hole pilot hole 22 gradually decreases toward one surface side of the profile 2 (that is, the surface side where the bottomed recess 23 opens). The through hole pilot hole 22 may be formed so that the thickness of the cylindrical portion of the hole finishing allowance 22s gradually increases. In this way, since the insertion hole finishing hole 22 having a larger diameter can be formed as compared with the case where the thickness of the insertion hole finishing allowance is gradually reduced toward the one surface side of the shaped member 2, The amount of processing in the hole forming step can be reduced.

  In the above-described embodiment, an example in which the left and right lid members 3 and 3 are used has been illustrated, but the number of lid members 3 is not limited. As shown in FIGS. 7 (a) and 7 (b), of course, even if one lid member 3 is used, there is no problem. Although illustration is omitted, three or more lid members may be used. There is no problem.

  In the embodiment described above, the case where the start position and the end position of the friction stirrer are provided in the finishing allowance of the steering shaft insertion hole 22 (finishing allowance 22s for the insertion hole) is illustrated, but (a) and (b) in FIG. As shown in FIG. 6, the starting position and the ending position of friction agitation may be provided in the finishing allowance of the fork attachment hole 21 (attachment hole finishing allowance 21s). Although there is no limitation on the form of the mounting hole finishing allowance 21s on the side where the friction stirring start position and end position are provided (left side in FIG. 7), the one shown in FIG. It consists of a cylindrical portion 21a that becomes the hole wall of the lower hole 21 and a bottom portion 21b that is a bottom wall and has a circular shape in plan view, and has an inverted U-shaped cross section.

  In the above-described embodiment, the base material 2 (bracket main body 1) is provided with the bottomed recess 23 (recess 13) and the cover member 3 is covered from one surface side of the base material 2, but FIG. As shown in FIG. 4, the base material 2 may be formed with an opening penetrating in the vertical direction, and the cover members 31 and 32 may be covered from both the front and back surfaces of the base material 2.

  In this case, the above-described manufacturing method may be repeated on the one surface side and the other surface side of the shaped member 2. That is, a first preparation step of covering the first lid member 31 at one opening end of the opening 23 ′ formed in the base material 2, an opening edge of the opening 23 ′, and the first lid member 31 A one-side friction stir welding step of relatively moving the rotary tool for friction stir welding along the friction stir route set so as to include a boundary line with the peripheral edge, and a first at the other opening end of the opening 23 ′. Friction along the second preparatory step of covering the two lid members 32 and the friction stir route set to include the boundary line between the opening edge of the opening 23 ′ and the peripheral edge of the second lid member 32. A one-side friction stir welding step including a second surface side friction stir welding step of relatively moving the rotating tool for stir welding, and a hole forming step of forming the fork attachment hole 11 and the steering shaft insertion hole 12, In the other side friction stir welding process, It is, ends the friction stir finishing allowance of a steering shaft insertion hole 12, the hole forming step may be performed processing to remove the finishing allowance.

  In this way, although the end position of the friction stirrer is provided in the shaped material 2, it is possible to eliminate the trace of the punched hole of the rotary tool, so that the shaped material is not impaired. 2 and the cover member 3 can be integrated. Further, the bracket B manufactured by this manufacturing method includes a closed space formed by closing the opening end of the opening 23 ′ with the first lid member 31 and the second lid member 32, so that it is lightweight. Although it is, it has high rigidity. In addition, although illustration is abbreviate | omitted, the base material provided with an opening part can be comprised with the extruded shape material made from an aluminum alloy. When the raw material is an extruded shape, the mounting hole pilot hole and the insertion hole pilot hole are also through holes.

  The above-described configuration and manufacturing method of the front fork bracket B includes a base member having a recess or an opening, and a lid member covering the recess or the opening, and an opening edge or opening of the recess. This can also be applied to a lidded structure in which the opening edge of the lid and the peripheral edge of the lid member are friction stir welded. In this case, it is only necessary to prepare a base material and a lid member as the base member, and apply the manufacturing method described above.

(A) is a perspective view which shows the bracket for front forks which concerns on one Embodiment of this invention, (b) is a top view similarly, (c) is X1-X1 sectional drawing of (b). (A) is a perspective view showing a shaped member and a lid member, (b) is a plan view of the shaped member, and (c) is an X2-X2 sectional view of (b). It is sectional drawing for demonstrating the manufacturing method of the bracket for front forks which concerns on one Embodiment of this invention. (A) And (b) is a top view for demonstrating the process following FIG. It is an expanded sectional view for demonstrating the manufacturing method of the bracket for front forks which concerns on one Embodiment of this invention, (a) is a figure which shows the mode of the start position of friction stirring, (b) is completion | finish of friction stirring. It is a figure which shows the mode of a position. It is a figure for demonstrating the modification of the manufacturing method of the bracket for front forks which concerns on embodiment of this invention, Comprising: (a) is a top view, (b) is X3-X3 sectional drawing of (a). It is a figure for demonstrating the other modification of the manufacturing method of the bracket for front forks which concerns on embodiment of this invention, Comprising: (a) is a top view, (b) is X4-X4 sectional drawing of (a). is there. It is sectional drawing for demonstrating the further another modification of the bracket for front forks which concerns on embodiment of this invention, and its manufacturing method. It is a schematic diagram for demonstrating the usage location of the bracket for front forks which concerns on embodiment of this invention.

Explanation of symbols

B Front fork bracket (structure with lid)
1 Bracket body (base member)
11 Fork mounting hole 12 Steering shaft insertion hole (through hole)
2 Substrate 21 Pilot hole for mounting hole 21s Finishing allowance for mounting hole 22 Pilot hole for insertion hole 22s Finishing allowance for insertion hole 3 Lid member

Claims (10)

A preparation step of covering a lid member on a bottomed recess recessed in one surface of a base material that is an element of the bracket body;
A friction stir welding step of relatively moving the rotary tool for friction stir welding along the friction stir route set to include a boundary line between the opening edge of the bottomed recess and the peripheral edge of the lid member;
A fork mounting hole penetrating the bracket body and a hole forming step for forming a steering shaft insertion hole, and a method for manufacturing a front fork bracket,
In the friction stir welding step, the friction stir is finished at the finishing allowance of the fork mounting hole or the steering shaft insertion hole,
In the hole forming step, a process for removing the finishing allowance is performed. On the other surface of the raw material, a fork hole or a steering hole for the steering shaft is provided in a recessed manner,
2. The method for manufacturing a front fork bracket according to claim 1, wherein, in the friction stir welding step, the friction stirring is finished at a bottom wall of the pilot hole serving as the finishing allowance.   3. The method for manufacturing a front fork bracket according to claim 1, wherein in the friction stir welding step, friction stirring is started from the finishing allowance.   The method for manufacturing a front fork bracket according to any one of claims 1 to 3, wherein the route includes an annular route provided so as to surround the lid member.   The method for manufacturing a front fork bracket according to claim 4, wherein a starting end portion and a terminal end portion of the annular route overlap each other. A first preparation step of covering the first lid member at one opening end of the opening formed in the raw material of the bracket body; and
One-surface friction stir welding that relatively moves a rotary tool for friction stir welding along a friction stir route set to include a boundary line between the opening edge of the opening and the peripheral edge of the first lid member Process,
A second preparation step of covering a second lid member on the other opening end of the opening;
The other side friction stirrer that relatively moves the rotary tool for friction stir welding along the friction stir route set to include a boundary line between the opening edge of the opening and the peripheral edge of the second lid member Joining process;
A fork mounting hole and a hole forming step for forming a steering shaft insertion hole, and a method for manufacturing a front fork bracket,
In the one surface side friction stir welding step and the other side friction stir welding step, respectively, the friction stirring is terminated at the finishing allowance of the fork mounting hole or the steering shaft insertion hole,
In the hole forming step, a process for removing the finishing allowance is performed. A preparation step of covering a lid member on a bottomed recess or opening formed in a base material that is a base member;
Relative rotation tool for friction stir welding along the friction stir route set to include the opening edge of the bottomed recess or the boundary between the opening edge of the opening and the peripheral edge of the lid member A friction stir welding process to move,
A hole forming step of forming a through hole in the base member, and a manufacturing method of a lidded structure,
In the friction stir welding step, the friction stir is finished at the finishing allowance of the through hole,
In the hole forming step, a process for removing the finishing allowance is performed. A bracket body having a recess or an opening;
A front fork bracket comprising: an opening edge of the recess or an opening edge of the opening and a peripheral edge of the lid member; Because
The bracket body has a fork mounting hole and a steering shaft insertion hole,
At least one of the fork mounting hole and the steering shaft insertion hole is formed in a portion including a friction stirring end position.   The bracket for a front fork according to claim 8, wherein the bracket body is a cast or forged product made of an aluminum alloy. A base member having a recess or an opening;
A lid member covering the recess or the opening, and the opening edge of the recess or the opening edge of the opening and the peripheral edge of the lid member are friction stir welded Because
The base member has a through hole;
The said through-hole is formed in the site | part including the completion | finish position of friction stirring, The structure with a lid | cover characterized by the above-mentioned.

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