JP2015009354A - Component provided with bush fixing part and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a component provided with a bush fixing part, which is formed of an extruded material and even when the bush fixing part is provided on a surface parallel to an extrusion direction, can secure strength of the bush fixing part without causing weight increase or the like.SOLUTION: The component (a lower arm) provided with a bush fixing part is manufactured by: cutting out an extrusion molding 26 provided with a tab 27 for molding the bush fixing part 18 by cutting off an extruded material to a constant length W and cutting off the molding from one cutting surface 28 relative to the tab in an extrusion direction A in dimension equal to thickness T of the bush fixing part or more to form a first joining surface 31; firstly starting cutting the first joining surface and cutting the surface, with the thickness dimension left, of the bush fixing part in parallel to the other cutting surface 29 of the tab to form a site 36 for molding the bush fixing part comprising a second joining surface 32; bending the site for molding the bush fixing part in a cylindrical shape; and butting and joining the second joining surface to the first joining surface so as to form the bush fixing part whose shaft center o1 direction is orthogonal to the extrusion direction and whose inner diameter D is larger than the constant length W.

Description

  The present invention relates to a bush mounting portion equipped part having a bush mounting portion and a method for manufacturing the same.

  A lower arm that connects a suspension frame and a steering knuckle of a four-wheeled vehicle is generally made of a steel plate, but has been manufactured by casting and forging aluminum in response to a recent demand for weight reduction. However, due to the high material costs, aluminum lower arms are not yet common. Therefore, a method of manufacturing a lower arm with an extruded material of aluminum or an aluminum alloy having a low material cost and good manufacturability is being developed.

  In the case of manufacturing with the above-described extruded material, the lower arm has a structure having a bush mounting portion on each of a plane perpendicular to the extrusion direction and a plane parallel to the extrusion direction. For this reason, when a lower arm is manufactured with an extrusion material, it does not become a problem to form a bush attachment part (rear side fastening part) on a surface perpendicular to the extrusion direction. However, for the bush mounting portion (front side fastening portion) provided on the surface parallel to the extrusion direction, the thickness of the extruded material (length along the extrusion direction) is required by the outer diameter of the bush. For this reason, problems such as an increase in weight, interference with peripheral parts, and a decrease in yield occur in the lower arm.

  Therefore, for the bush mounting portion having a surface parallel to the extrusion direction, the bush mounting portion manufactured separately must be welded. However, since a high stress is generated particularly in the vicinity of the welded portion on the upper side of the vehicle due to the balance with peripheral parts such as a steering knuckle, the base material whose strength has been lowered due to the heat effect of welding may be damaged.

  On the other hand, Patent Documents 1 and 2 disclose conventional bush mounting part deficient parts. Patent Document 1 discloses a suspension arm manufactured from an iron pipe, which is welded after bending to form a bush mounting portion. Further, Patent Document 2 discloses a cylindrical mount device made of an aluminum extruded material, and the pressed concave portion and the convex portion are mechanically engaged to form a bush mounting portion.

Japanese Patent Laid-Open No. 7-25215 JP-A-9-317988

  However, Patent Document 1 does not hold for a solid material, and the thickness of the bush mounting portion and the length in the axial direction depend on the thickness of the pipe and the diameter of the pipe, and the shape is limited. Furthermore, since the joining method is welding and the welding area is small, there is a concern that the strength of the bush mounting portion may be reduced. Patent Document 2 forms a bush mounting portion on a surface perpendicular to the extrusion direction, and there is no description regarding forming the bush mounting portion on a surface parallel to the extrusion direction.

  The object of the present invention is made in consideration of the above-mentioned circumstances, and even when a bush mounting portion is provided on a surface formed by an extruded material and parallel to the extrusion direction, an increase in weight or the like is caused. In addition, the present invention is to provide a bush mounting portion-equipped component and a method for manufacturing the same, which can ensure the strength of the bush mounting portion.

  The method for producing a bush mounting part-equipped component according to the present invention is a cutting step of forming an extruded body having a tab for forming a bush mounting part by cutting a metal extruded material into a predetermined length and cutting it out. And a first cutting step of forming a first joint surface by cutting with a dimension equal to or larger than the thickness of the bush mounting portion in the extrusion direction from one cut surface to the tab of the extruded molded body, Cutting is started from the joining surface, and cutting is performed in parallel with the other cutting surface of the tab leaving the thickness dimension of the bush mounting portion from the other cutting surface, and the second joining is performed on the tip surface of the tab. A second cutting step for forming a bush attachment portion forming portion having a surface, bending the bush attachment portion forming portion into a cylindrical shape, and setting the second joint surface of the bush attachment portion forming portion to the first joint surface And bending process to match Joining the second joint surface butted to the first joint surface to form the bush mounting portion whose axial direction is orthogonal to the extrusion direction and whose inner diameter is larger than the predetermined length; and It is characterized by having.

  Moreover, the bush attachment part equipped part which concerns on this invention was manufactured by the manufacturing method of the bush attachment part equipped part of the said invention, It is characterized by the above-mentioned.

  According to the present invention, the tab of the extruded product obtained by cutting the extruded material into a certain length is cut to form the bush attachment portion forming portion having the second joint surface and the first joint surface, and the bush attachment portion molding. The portion is bent into a cylindrical shape, and the first joint surface and the second joint surface are joined to form a bush mounting portion whose axial center direction is orthogonal to the extrusion direction and whose inner diameter is larger than the predetermined length. As a result, even when the bush mounting part equipped part is formed of an extruded material and the bush mounting part is provided on a surface parallel to the extrusion direction, the fixed length of the extruded product is set to be equal to or larger than the inner diameter of the bush mounting part. The first attachment surface is formed by cutting the tab from one of the cut surfaces to the thickness of the bush attachment portion. The joining area increases and the strength of the bush mounting portion can be secured.

The partial front view which shows the circumference | surroundings of the lower arm which is a bush attachment part equipped component manufactured by the manufacturing method of the bush attachment part equipped component which concerns on this invention. II arrow line view of FIG. The perspective view which shows the extrusion body before cutting out the extrusion molding for lower arm shaping | molding of FIG. The front view which shows the extrusion molded object cut out from the extrusion body of FIG. Explanatory drawing which shows the process of forming a bush attaching part from this tab in the V arrow state of the tab of the extrusion molding in FIG. Explanatory drawing which shows the process of forming a bush attaching part from the tab of FIG. 5 from diagonally upward. Explanatory drawing corresponding to FIG. 5 which shows other embodiment in the manufacturing method of the bush attachment part components which concern on this invention. Explanatory drawing corresponding to FIG. 5 which shows other embodiment in the manufacturing method of the bush attachment part components which concern on this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a partial front view showing the periphery of a lower arm, which is a bush mounting part equipped part manufactured by the method of manufacturing a bush mounting part equipped part according to the present invention, and FIG. is there. The bush attachment portion equipped component of the present embodiment is a lower arm (front lower arm) 10 shown in FIGS. 1 and 2. The lower arm 10 connects a suspension frame 11 and a steering knuckle 12 of a four-wheeled vehicle, and a force Fy in the vehicle front-rear direction and a force Fx in the vehicle left-right (inside / outside) direction from the tire 13 via the steering knuckle 12. Works.

  The lower arm 10 is fastened to the suspension frame 11 by a front side fastening part 14 and a rear side fastening part 15 and supports the steering knuckle 12 via a ball joint 17 attached to the ball joint mounting part 16. The front side fastening portion 14 is fastened to the suspension frame 11 via the bush 19 by press-fitting a bush 19 into a bush mounting portion 18 having the axial center O1 direction as the vehicle front-rear direction. Further, the rear side fastening portion 15 is fastened to the suspension frame 11 via the bush 21 by press-fitting a bush 21 into a bush mounting portion 20 with the axis O2 direction as the vehicle vertical direction.

  Now, the lower arm 10 having the ball joint mounting portion 16, the bush mounting portion 18, the bush mounting portion 20, and the like described above is made from an extruded material 25 (FIG. 3) made of metal containing aluminum or magnesium (in this embodiment, an aluminum alloy). Manufactured. The extruded material 25 has a uniform cross-sectional shape. When the lower arm 10 shown in FIG. 2 is manufactured, the extruded material 25 is first cut into a certain length (constant width) W along the extrusion direction A. By doing so, the cutting process which cuts out the some extrusion molded object 26 (FIG. 4) is implemented.

  Here, the extrusion direction A of the extruded material 25 coincides with the vehicle vertical direction of the lower arm 10. For this reason, the ball joint mounting portion 16 and the bush mounting portion 20 formed on the surface perpendicular to the extrusion direction A are formed simultaneously with the extrusion molding of the extruded material 25. However, the bush mounting portion 18 in which the axial center O1 is formed on a plane perpendicular to the extrusion direction A and parallel to the extrusion direction A is not formed simultaneously with the extrusion molding of the extruded material 25.

  As for the bush mounting portion 18, a first cutting step and a second cutting are performed on the tab 27 for forming the bush mounting portion 18 in the extruded body 26 (FIG. 4) cut out from the extruded material 25 shown in FIG. 3 as described later. It forms by performing a process, a bending process, and a joining process one by one. In addition, the ball joint attachment part 16 and the bush attachment part 20 are formed in the main body part 24 in the extrusion molded body 26, respectively.

  That is, as shown in FIGS. 5A and 6A, the tab 27 of the extrusion molded body 26 is formed with one cut surface 28 and the other cut surface 29 cut in the cutting step. Has been. Here, when the lower arm 10 is formed from the extruded molded body 26, one cut surface 28 is on the lower side of the vehicle, and the other cut surface 29 is on the upper side of the vehicle. In the first cutting process, the tab 27 is cut in the extrusion direction A from one cut surface 28 with a thickness T (FIG. 5C) or more of the bush mounting portion 18 to obtain the first joint. Surface 31 is formed. The first joint surface 31 is formed so as to penetrate from the one side surface 33 of the tab 27 to the other side surface 34 on the opposite side in the direction of the axis O1 of the bush mounting portion 18.

  Next, the second cutting step shown in FIGS. 5B and 6B is performed. That is, in the second cutting step, cutting is started from the first joint surface 31 and penetrated in the direction of the axis O1 of the bush mounting portion 18 in parallel with the other cutting surface 29 of the tab 27, the other cutting surface 29. Cutting is performed from the cutting surface 29 leaving the dimension of the thickness T of the bush mounting portion 18, and in the vicinity of the distal end surface 35 of the tab 27, in the state of penetrating in the direction of the axis O <b> 1 of the bush mounting portion 18. A bush attachment portion molding portion 36 having a second joint surface 32 on the distal end surface 35 is formed by curving and cutting.

  Accordingly, the bush attachment portion molding portion 36 has a portion where the thickness T0 matches the thickness T of the bush attachment portion 18, and the length L along the extrusion direction A of the second joint surface 32 is the thickness. It is set to be larger than T0. Furthermore, the length L along the extrusion direction A of the second bonding surface 32 is such that when the second bonding surface 32 is bonded to the first bonding surface 31 in the bonding process described later, The two cut surfaces 28 and the other cut surface 29 are set to be a continuous plane with the joint portion 37 (FIG. 5C) with the two joint surfaces 32 interposed therebetween. In addition, the second joint surface 32 in the bush attachment portion molding portion 36 is set to have a substantially equivalent area to the first joint surface 31.

  Next, the bending process shown in FIGS. 5C and 6C is performed. In this bending step, the bush attachment portion forming portion 36 formed in the second cutting step is moved to one cut surface 28 side (the vehicle lower surface side) with an arrow B (FIG. 5B) using a roll bender or a press. The second joint surface 32 of the bush mounting portion molding portion 36 is abutted against the first joint surface 31 by bending in the direction.

  A joining process is implemented after this bending process. In this joining step, the bush attachment portion 18 is formed by joining the second joining surface 32 of the bush attachment portion forming portion 36 butted in the bending step to the first joining surface 31. Although the said joining is welding, friction stir welding, joining by an adhesive agent, or caulking joining etc., welding is used in this embodiment. Further, a joint portion 37 between the second joint surface 32 and the first joint surface 31 of the bush attachment portion molding portion 36 is provided on the vehicle lower side of the lower arm 10 and perpendicular to the one cut surface 28. Further, the joint area P of the joint portion 37 is a sectional area Q of the portion having the thickness T of the bush mounting portion 18 formed by this joining step (thickness T × the length K in the axial direction of the bush mounting portion 18). ).

  Further, the bush mounting portion 18 formed in this joining step is set such that the direction of the axial center O1 is orthogonal to the extrusion direction A and the inner diameter D thereof is larger than the fixed length W of the extrusion molded body 26. . A bush 19 shown in FIG. 2 is press-fitted into the bush mounting portion 18 to provide a front side fastening portion 14. A bush 21 is press-fitted into the bush mounting portion 20 to provide a rear side fastening portion 15. A ball joint 17 is attached. In this way, the lower arm 10 is manufactured as a bush mounting part equipped part.

With the configuration as described above, the following effects (1) to (4) are achieved according to the present embodiment.
(1) As shown in FIGS. 3 to 6, a bush mounting portion provided with a second joint surface 32 by cutting a tab 27 of an extruded body 26 obtained by cutting an extruded material 25 made of aluminum alloy into a predetermined length W. The molding part 36 and the first joint surface 31 are formed, the bush mounting part molding part 36 is bent into a cylindrical shape, the first joint surface 31 and the second joint surface 32 are joined, and the axial center O1 direction is A bush mounting portion 18 that is orthogonal to the extrusion direction A and has an inner diameter D larger than a certain length W is formed.

  As a result, even when the lower arm 10 is formed of the extruded material 25 and the bush mounting portion 18 is provided on a surface parallel to the extrusion direction A, the fixed length W of the extruded body 26 is set to the inner diameter D of the bush mounting portion 18. By setting as described above, there is no increase in the weight of the lower arm 10 or interference with peripheral parts.

  Further, since the first joint surface 31 is formed by cutting the tab 27 from one cut surface 28 to a thickness T or more of the bush mounting portion 18, the first joint surface 31 and the first joint surface 31 are substantially the same. The joint area P of the joint portion 37 where the second joint surface 32 having the same area is joined is larger than the cross-sectional area Q of the portion having the thickness T of the bush mounting portion 18. Thereby, the coupling strength of the bush mounting portion 18 can be sufficiently ensured.

  (2) In the bush mounting portion 18 of the lower arm 10, the joint portion 37 between the first joint surface 31 and the second joint surface 32 is provided on the lower arm 10 on the vehicle lower side. Therefore, as shown in FIG. 2, the vehicle of the bush mounting portion 18 where stress concentrates on the vehicle front-rear direction force Fy and the vehicle left-right direction force Fx acting on the ball joint mounting portion 16 of the lower arm 10 from the tire 13. There will be no joint 37 in the upper part. Also from this point, the strength of the bush mounting portion 18 is ensured, and the bush mounting portion 18 can be prevented from being damaged.

  (3) As shown in FIG. 5, the bush mounting portion 18 of the lower arm 10 has one cut surface 28 and the other cut surface 29 sandwiching a joint portion 37 between the first joint surface 31 and the second joint surface 32. The second joint surface 32 is formed by cutting in the second cutting step so that the surface becomes a continuous plane. For this reason, even when the second joint surface 32 and the first joint surface 31 of the bush mounting portion molding portion 36 are abutted in the bending process, one cut surface 28 and the other cut surface sandwiching these abutting surfaces. 29, since there is no step, this abutting surface can be satisfactorily joined using, for example, friction stir welding.

  (4) The width M of the connecting portion 38 between the bush mounting portion 18 (tab 27) and the main body portion 24 in the lower arm 10 (extrusion molded body 26) shown in FIGS. 2 and 4 is the bush mounting portion 18 (tab 27). Even when the length K is smaller than the axial length K, the joint portion 37 when the bush mounting portion 18 is formed has a large cross-sectional area defined by the axial length K of the bush mounting portion 18. . For this reason, the stress which generate | occur | produces in the said joining location 37 vicinity becomes small, and the failure | damage of this joining location 37 can be prevented reliably.

  As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. This embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention.

  For example, as shown in FIG. 7, the first joint surface 41 formed on the tab 27 in the first cutting process is formed in a bowl shape having a step 43, and is formed in the bush attachment portion forming portion 36 in the second cutting process. The second joint surface 42 may be formed in a bowl shape having a step 44 that can be engaged with the first joint surface 41. In this case, since the contact state between the first joint surface 41 and the second joint surface 42 can be maintained only by abutting the first joint surface 41 and the second joint surface 42 during the bending process, In the joining process for forming the portion 18, there is no need to use a positioning jig for joining.

  Further, as shown in FIG. 8, the first joint surface 51 formed on the tab 27 in the first cutting step is set closer to the distal end surface 35 side of the tab 27 than in the embodiment shown in FIG. The bush mounting portion 18 is formed by bending the second joint surface 52 formed on the tip end surface 35 of the tab 27 to the first joint surface 51. Thereby, since the length N of the tab 27 can be shortened from the length N0 in the case of the said one embodiment, the material usage-amount of the extrusion material 25 can be reduced.

10 Lower arm (Bush mounting part equipped parts)
DESCRIPTION OF SYMBOLS 11 Suspension frame 12 Steering knuckle 14 Front side fastening part 18 Bushing attachment part 25 Extrusion material 26 Extrusion molding 28 One cutting surface 29 The other cutting surface 31 The 1st joining surface 32 The 2nd joining surface 35 The front end surface 36 Bushing attachment part shaping | molding site 37 Joint location 41 1st joint surface 42 2nd joint surface 43, 44 Step A Extrusion direction D Inner diameter K of bush mounting portion P Length in axial direction P Joint area Q Cross section T Thickness of bush mounting portion

Claims (10)

A cutting step of forming an extrusion molded body provided with a tab for forming a bush mounting portion by cutting a metal extruded material into a certain length and cutting it;
A first cutting step of forming a first joint surface by cutting with a dimension equal to or greater than the thickness of the bush mounting portion from one cut surface to the extrusion direction with respect to the tab of the extruded molded body;
Cutting is started from the first joint surface, and cutting is performed in parallel with the other cut surface of the tab, leaving the thickness dimension of the bush mounting portion from the other cut surface, to the tip surface of the tab. A second cutting step for forming a bush mounting portion forming portion having a second joint surface;
Bending the bush mounting part molding part into a cylindrical shape, and bending the second joint surface of the bush mounting part molding part to the first joint surface;
Joining the second joint surface butted in the bending step to the first joint surface to form the bush mounting portion whose axial direction is orthogonal to the extrusion direction and whose inner diameter is larger than the predetermined length. A method of manufacturing a bush mounting part-equipped component. 2. The bush attachment according to claim 1, wherein the second joint surface of the bush attachment portion forming portion formed in the second cutting step has a substantially equivalent area to the first joint surface formed in the first cutting step. Manufacturing method of parts and components. The joint area between the second joint surface of the bush mounting portion forming part formed in the second cutting step and the first joint surface formed in the first cutting step is set larger than the cross-sectional area of the bush mounting portion. The method for manufacturing a part having a bush mounting portion according to claim 2. The second joint surface of the bush mounting portion molding part formed in the second cutting step is joined by the first and second joint surfaces after the joint step joined with the first joint surface formed in the first cutting step. The bush according to any one of claims 1 to 3, wherein the bush is formed in the second cutting step so that one cut surface and the other cut surface are continuous planes. A method for manufacturing an attachment part component. The first joint surface formed in the first cutting step is formed in a bowl shape having a step, and the second joint surface of the bush mounting portion forming portion formed in the second cutting step can be engaged with the first joint surface. 5. The method for manufacturing a bush mounting part equipped part according to any one of claims 1 to 4, wherein the bush mounting part is formed into a bowl shape having a step. 6. The method for manufacturing a part having a bush mounting portion according to claim 1, wherein the metal of the extruded material is a metal containing aluminum or magnesium. The joining of the first joining surface and the second joining surface performed in the joining step is welding, friction stir welding, joining using an adhesive, or caulking joining, or any one of claims 1 to 6. The manufacturing method of the bush attachment part equipped components of description. 8. The lower arm for connecting a suspension frame and a steering knuckle of a four-wheeled vehicle, wherein the bush mounting portion provided part in which the bush mounting portion is formed in the joining step is a lower arm that connects the suspension frame and the steering knuckle of the four-wheeled vehicle. The manufacturing method of the bush attachment part equipped components of description. The method for manufacturing a component having a bush mounting portion according to claim 8, wherein a joint portion between the first joint surface and the second joint surface that are joined in the joining step is provided on a vehicle lower side of the lower arm. A bush mounting part equipped component manufactured by the method for manufacturing a bush mounting part equipped component according to any one of claims 1 to 9.

Images