JP4714663B2 - Manufacturing method for vehicle wheel - Google Patents

Description

  The present invention relates to a method for manufacturing a vehicle wheel.

  A method of casting a vehicle wheel with a light metal such as an aluminum alloy is known. In such a casting method, a mold having a disk-shaped disk forming space and a cylindrical rim forming space is prepared. A gate is connected to the center or side surface of the disk molding space, and a molten metal is injected from the gate to fill the disk molding space and the rim molding space in order.

  In the above casting process, it is necessary to fill the molten space in a short rim from the complex shaped disk molding space to the narrow rim molding space in a short time. The annular connection at the boundary of the space is widened.

  In the vehicle wheel manufacturing method described above, since the vehicle wheel close to the final shape is molded at once, the mold structure becomes complicated and the manufacturing cost is high.

  Further, in the solidification process after filling the molten metal, solidification starts from the rim tip and progresses toward the connection location, but since the amount of the molten metal in the annular connection portion is large, before this, Solidification begins, and the annular connection finally solidifies. For this reason, there is a possibility that a casting defect such as a shrinkage nest will occur at this connection portion. As a result, it was difficult to improve the solidification rate of the disk part, and there was concern about deterioration of mechanical properties.

  Further, in the vehicle wheel having the final shape, the boundary between the disk and the rim corresponding to the annular connection portion is thicker than necessary even though the required strength is low, and the material is wasted.

  The disadvantages of the above casting method become more prominent as the diameter, rim width and thickness of the vehicle wheel to be cast increase. This is because the larger the diameter is, the wider the annular connecting portion is and the higher the castability is. Therefore, the occurrence rate of casting defects is increased, the material is wasted, and the weight cannot be reduced.

  Patent Document 1 discloses a method of manufacturing a vehicle wheel by preparing first and second parts and friction-welding them. More specifically, the first component has a disk and one end of the rim, and has a substantially disk shape. Further, the second part has a cylindrical shape with the most part of the rim, that is, the middle part and the other end part of the rim being integrated.

The first part has an annular recess at the boundary between the disk and one end of the rim, and has a pair of annular first joint surfaces located radially outside and inside the annular recess. ing.
On the other hand, the second part has a pair of annular second joint surfaces facing one pair of first joint surfaces of the first part on one end face thereof.

  And a wheel original form is obtained by welding a pair of 1st joint surface of the said 1st component, and a pair of 2nd joint surface of a 2nd component. Thereafter, the final vehicle wheel is obtained by cutting. In addition to arc welding, laser welding, etc., friction welding is taught as the above welding.

  Since the manufacturing method of Patent Document 1 manufactures the first and second parts separately, there is a possibility that the manufacturing cost can be reduced. Further, since an annular cavity is formed at the boundary between the disk and the rim, it is possible to reduce the weight and reduce the waste of materials. Note that Patent Document 1 does not describe individual manufacturing steps of the first and second parts.

Patent Document 2 also discloses a method of manufacturing a vehicle wheel using two parts. In particular, in the third embodiment shown in FIG. 3 of Patent Document 2, the disk is obtained by forging or forging after casting. The rim is obtained by casting a thick preform and then spinning the preform. Then, as in the second embodiment shown in FIG. 2, the wheel rim is obtained by friction-welding the inner periphery of the rim to the outer periphery of the disk. Thereafter, the final vehicle wheel is obtained by cutting.
JP 2000-289402 A Japanese Patent No. 2838593

  In Patent Document 1, when arc welding or the like is used when two parts are welded, there is a possibility that the material is modified by the heat. Further, when using friction welding, there are the following disadvantages.

  The friction welding is realized by rotating one part relative to the other part and pressing one part closer to the other with a large force (thrust). For this reason, the first and second parts are required to have a strength capable of withstanding a large thrust (or a reaction force thereof).

  In Patent Document 1, the thrust (or reaction force) received by the pair of second joining surfaces is ultimately borne by the middle part of the rim. There is a risk of inviting.

  In addition, since the second joint surface on the radially outer side in the second part is formed in the vicinity of the outer peripheral edge of the flange portion that projects in the radial direction from the middle portion of the rim, the thrust received by the second joint surface on the radially outer side (Or the reaction force) is borne by the buttocks that are orthogonal to the direction in which the thrust acts. For this reason, a large stress is applied to the inner peripheral edge portion (connecting portion with the intermediate portion of the rim) of the flange portion, which may cause deformation.

  As described above, in Patent Document 1, there is a possibility that the second part may be deformed at the time of friction welding, and in order not to cause this deformation, it is necessary to reduce the thrust, resulting in deterioration of the bonding quality.

  In the case of the third embodiment of Patent Document 2, since the intermediate portion of the rim is located at substantially the center of the joint surface of the rim, it is estimated that the friction welding condition is better than Patent Document 1, but the rim Since the middle part is thin, thrust cannot be sufficiently applied. Further, in Patent Document 2, since the boundary between the disc and the rim is thick, the material is wasted and does not contribute to weight reduction of the vehicle wheel.

The present invention has been made to solve the above problems, and in a method for manufacturing a vehicle wheel,
(A) A substantially disk-shaped first part integrally having a disc and one end of a rim, and a cylindrical second part provided as a thick-walled rim preform, are prepared.
The first part has an annular recess at the boundary between the disk and one end of the rim, and has a pair of annular first joint surfaces located radially outside and inside the annular recess. ,
The second component has a pair of annular second bonding surfaces facing the pair of first bonding surfaces of the first component on one end surface thereof,
(A) Friction welding the pair of first joint surfaces of the first part and the pair of second joint surfaces of the second part;
(C) The second part is spun after the friction welding to form an intermediate part and the other end of the rim.

According to the said structure, since the vehicle wheel is manufactured by two components, manufacturing cost can be reduced. In addition, since an annular cavity is formed at the boundary between the disk and the rim, which does not require a high strength, it is possible to save material and reduce the weight of the vehicle wheel.
Further, the thinning, lightening, and high strength of the rim can be achieved by spinning.
In addition, since friction welding is used, the amount of heat input is small, so there is little material modification or deformation, no molten material is required, and welding costs are low.
Furthermore, since the second component is thick during the friction welding, a large thrust received from the pair of second joining surfaces can be borne without being deformed, and the joining quality can be improved.

  Preferably, the first component is a light metal cast or forged after casting. According to this, the first part can be cast at low cost, and the occurrence of casting defects such as nests can be suppressed or prevented. As a result, the solidification rate can be improved, and the mechanical properties can be improved.

  Preferably, the second part is obtained by casting a light metal. According to this, the second part can be cast at low cost, and the occurrence of casting defects such as nests can be suppressed or prevented.

Preferably, the second component is a cylindrical shape obtained by extruding a light metal, or a cylindrical extruded product processed into a substantially conical shape.
According to this, a 2nd component can be obtained further cheaply.

  According to the present invention, a lightweight and high-strength vehicle wheel can be manufactured at low cost.

  A vehicle wheel manufacturing method according to the first embodiment of the present invention will be described below with reference to FIGS. Briefly, the disk-shaped first part 10 and the cylindrical second part 20 made of a cast product of an aluminum alloy (light metal) are friction welded to obtain a wheel initial form 1 indicated by a solid line in the figure, Next, spinning is performed to obtain a wheel original shape 2 indicated by a broken line, and then cutting is performed to obtain a vehicle wheel 3 having a final shape indicated by a two-dot chain line.

  First, the first component 10 as a cast product or a forged product after casting will be described. The first component 10 includes a disk 11 and one end 12 of the rim.

  The disk 11 has the same or similar shape as that of a normal vehicle wheel disk, and has spoke portions 11a of FIG. 1 and decorative holes 11b of FIG. 2 alternately in the circumferential direction.

  The one end portion 12 of the rim has one flange portion 12a of the rim and one bead seat portion 12b.

  An annular recess 15 is formed on one surface at the boundary between the disk 11 and the one end 12 of the rim. In the present embodiment, the cross-sectional shape of the recess 15 is different between a location corresponding to the spoke portion 11a and a location corresponding to the decorative hole portion 11b. In the present embodiment, the annular recess 13a is continuous over the entire circumference, but may be interrupted by arranging ribs or the like at predetermined intervals without being continuous.

  On one surface of the border, the radially inner and radially outer regions of the annular recess 15 are provided as a pair of first joint surfaces 18 and 19. The pair of first joining surfaces 18 and 19 are on a common virtual conical surface A centering on the axis Ox of the first component 10. The first joint surfaces 18 and 19 may be positioned on a virtual plane orthogonal to the axis Ox instead of the virtual conical surface A.

  The second component 20 is cast as a thick rim preform, and generally has a cylindrical shape that spreads in a conical shape at a relatively gentle angle from one end to the other end.

  More specifically, in the inner periphery of the second component 20, a region extending a predetermined distance from one end forms a cylindrical surface 21, and a conical surface 22 extends from this region toward the other end. On the other hand, on the outer periphery of the second component 20, a portion away from one end by a predetermined distance (shorter than the region where the cylindrical surface 21 is formed) has a minimum diameter, and a conical surface 24 is formed from the minimum diameter portion 23 toward the other end. ing.

  On the outer periphery of the second component 20, an annular flange 25 is formed between the one end and the minimum diameter portion 23 so as to protrude in a substantially radial direction.

  In the second part 20, the conical main portion 26 defined by the inner and outer conical surfaces 22 and 24 has a uniform thickness. A portion sandwiched between the cylindrical surface 21 on the inner periphery and the minimum diameter portion 23 on the outer periphery has a minimum thickness, and the thickness gradually increases from the minimum diameter portion 23 toward the main portion 26. And the site | part which formed the collar part 25 becomes the maximum thickness in the 2nd component 20. FIG. The main part may not have a uniform wall thickness.

  One end surface of the second component 20 forms a conical surface 27 having the same shape as the virtual conical surface A. Regions near the inner peripheral edge and the outer peripheral edge of the conical surface 27 are provided as a pair of second joining surfaces 28 and 29.

  Since the disk-shaped first part 10 and the thick cylindrical-shaped second part 20 spreading in a conical shape have a relatively simple structure, they can be cast easily and at low cost, and the occurrence of casting defects is suppressed or suppressed. Can be prevented.

  The first component 10 and the second component 20 having the above-described shapes are frictionally produced by rotating one of the first component 10 and the second component 20 relative to the other with the first bonding surfaces 18 and 19 and the second bonding surfaces 28 and 29 in contact with each other. Pressure welding (friction welding). By this friction welding, a wheel initial form 1 indicated by a solid line is obtained.

  During the friction welding, a large axial force (thrust) that presses one component toward the other component is applied. At this time, in the first component 10, the thrust (or reaction force) applied to the first joint surfaces 18 and 19 is received without being deformed by a portion extending over a predetermined distance in the axial direction or oblique direction.

  On the other hand, in the second component 20, the thrust (or reaction force) applied to the second joint surfaces 28 and 29 is received without being deformed by the main portion 26 having a thick wall. The thrust (or reaction force) applied to the outer second joining surface 29 is transmitted to the main portion 26 via the flange 25, but the main portion 26 is thick and has a diameter of the flange 25. Since the protruding amount in the direction is small, the flange portion 25 can receive a large thrust (or its reaction force) without being deformed. As a result, good bonding quality can be obtained.

  By the friction welding, the annular recess 15 of the first component 10 is closed by one end surface of the second component 20 to form an annular cavity 30. Since this portion does not require great strength, the cavity 30 may be formed. This cavity 30 can save material and reduce the weight of the vehicle wheel.

  After the friction welding, a spinning process (flow forming process) is applied to the wheel initial form 1 to obtain a wheel original form 2 indicated by a broken line. By this spinning process, a thin-walled and high-strength rim can be obtained.

  The spinning process is performed with the cylindrical surface 21 of the second component 20 fitted on the mandrel. Specifically, the minimum diameter portion 23 and the main portion 26 are spun into a predetermined thin shape, and the rim drop portion 20a (the middle portion of the rim) and the other end portion 20b are formed. The other end portion 20b of the rim includes the other bead seat portion 20c and the other flange portion 20d.

  In the spinning process, the thickness at the minimum diameter portion 23 decreases, and as a result, the protrusion amount of the flange portion 25 increases. The flange portion 25 provides a step between the one bead sheet portion 12b and the drop portion 20a.

  After the spinning process, cutting is performed to obtain a vehicle wheel 3 having a final shape indicated by a two-dot chain line.

  In the above embodiment, the first component 10 and the second component 20 may be formed of the same material, but may be formed of different materials. For example, for the first part 10, for example, an Al—Si alloy is used as a material suitable for casting and having high mechanical properties, and for the second part 20, as a material suitable for casting and suitable for spinning and having high mechanical properties. For example, Al—Mg, Al—Mg—Si, and Al—Zn—Mg alloys are used.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals in the drawing, and the description thereof is omitted. In the second embodiment, one end surface of the second component 20 is not a conical surface, but has an annular shallow recess 27 a that faces the annular recess 15 of the first component 10. A pair of second joining surfaces 28 and 29 are formed on the inside and outside in the radial direction of the recess 27a.

The present invention is not limited to the above embodiment, and various aspects can be adopted. For example, the second component 20 may be thicker than the above embodiment, and the collar portion 25 may be eliminated.
You may comprise the 2nd component 20 with a cylindrical-shaped extrusion. Further, this cylindrical extrudate may be processed into a conical shape similar to the above embodiment.

It is principal part sectional drawing explaining the manufacturing method of the vehicle wheel which makes 1st Embodiment of this invention, and is sectional drawing in a spoke part. In this figure, the solid line shows the form immediately after friction welding, the broken line shows the form after the completion of spinning, and the two-dot chain line shows the form after cutting. It is principal part sectional drawing explaining the manufacturing method, and is sectional drawing in a decoration window part. FIG. 3 is a view corresponding to FIG. 1 for explaining a method for manufacturing a vehicle wheel according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel initial form after friction welding process 2 Wheel original form 3 after spinning processing Vehicle wheel 10 of final shape after cutting 10 First part 11 Disc 12 One end part 15 of rim Annular recesses 18 and 19 First joint surface 20 First 2 parts 20a Rim drop part (intermediate part of rim)
20b Other end portions 28 and 29 of the rim Second joint surface

Claims (6)

(A) preparing a substantially disc-shaped first part integrally having a disc and one end of a rim, and a cylindrical second part provided as a rim preform;
One end portion of the rim in the first part has one flange portion and one bead seat portion,
Above the boundary portion between the one end of the disc and the rim in the first part, the annular opening toward the second part to be joined together are located radially inward of one bead seats the A concave portion is formed, and an annular first joining surface facing the second part to be joined is formed between the annular concave portion and the bead sheet portion, and also on the radially inner side of the annular concave portion. , Another annular first joining surface facing the second part to be joined is formed,
The second part has one end part on the first part side to be joined, and a part that is connected to the one end part and that is scheduled for spinning processing, and the spinning process scheduled part is thicker than the final shape, On the outer periphery of the one end portion of the second part, an annular collar portion is formed that protrudes radially outward from the spinning scheduled portion,
Furthermore, the second component has a pair of annular second bonding surfaces facing the pair of first bonding surfaces of the first component on one end surface thereof, and is radially outside of the pair of second bonding surfaces. A second joint surface is disposed on the collar,
(A) By rotating the first part and the second part relative to each other while applying an axial force, the pair of first joint surfaces of the first part and the pair of second joint surfaces of the second part Friction welding,
(C) After the friction welding, the spinning part to be processed of the second part is spun to form the entire area of the drop part of the rim, and the other bead sheet part and the other flange part are used as the other end part of the rim. And a vehicle wheel manufacturing method. One end surface of the second part forms a continuous conical surface, and the conical surface includes the pair of second joining surfaces,
2. The method for manufacturing a vehicle wheel according to claim 1, wherein the pair of joining surfaces of the first part are arranged on a virtual conical surface having the same shape as the conical surface of the second part. The spinning process scheduled part of the second part has a conical shape in which the diameter gradually increases from one end to the other end, the outer diameter of the part adjacent to the buttocks is minimized, and the part that forms this minimum diameter is used. The method for manufacturing a vehicle wheel according to claim 1, wherein the spinning process is performed over the other end of the spinning process scheduled part. The method for manufacturing a vehicle wheel according to any one of claims 1 to 3, wherein the first part is a light metal cast or forged after casting. The method for manufacturing a vehicle wheel according to any one of claims 1 to 4, wherein the second part is obtained by casting a light metal. 5. The vehicle according to claim 1, wherein the second part is a cylindrical one obtained by extruding a light metal, or a cylindrical extrudate is processed into a substantially conical shape. 6. Wheel manufacturing method.

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