JP2013155826A - Method of manufacturing balance weight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of easily manufacturing a balance weight to whichf a clip is fixed with high strength, by pressing work.SOLUTION: A lower mold 4, on which a shaft raw material 1 is to be placed, and an upper mold 5 including: a forming surface 51 facing a receiver groove 41 of the lower mold 4; a forming projecting part 52 projecting from a part of the forming surface 51; and a forming recessed part 53 recessed in a central part of the forming projecting part 52 are prepared. The shaft raw material 1 is placed in the receiver groove 41 of the lower mold 4, and the upper mold 5 is lowered to form a weight shaft 2, which includes a flat receiver surface 22 and a projection 23 projecting from a central part of the flat receiver surface 22, in a part of a peripheral surface of the shaft raw material 1. A clip 3 provided with a hole 31 is placed on the flat receiver surface 22 of the weight shaft 2 inside the receiver groove 41, and the projection 23 is fitted in the hole 31. The clip 3 is fixed to the weight shaft 2 by swaging a tip end of the projection 23 by swaging work.

Description

  The present invention relates to a method for manufacturing a balance weight that is attached to a rim portion of a wheel for a wheel and adjusts the weight balance of the wheel for the wheel.

  Mass-produced wheel wheels are not well balanced over the entire circumference, and there are unbalanced ones. When tires are mounted on unbalanced wheel wheels, the wheels vibrate when the vehicle is running, It is specified by the automotive parts industry that it is necessary to attach a balance weight to a part of the rim of the wheel wheel in the circumferential direction and adjust the weight balance of the wheel wheel. ing.

  The balance weight is manufactured by disposing a clip attached to a part of the rim portion of the wheel for the wheel in the circumferential direction in a mold cavity, injecting molten lead into the cavity, and insert-molding the clip into a lead member. As described in Patent Document 1, a weight shaft is cut through a drawing process in which an iron wire is drawn and formed into a certain cross-sectional shape, and a bending process in which the wire is bent to a predetermined curvature radius. And a connecting step of integrally connecting a clip for attaching to a rim portion of a wheel for a wheel to a central portion in the longitudinal direction of the weight shaft. The connection process of Patent Document 1 is performed by any one of welding, adhesive, caulking, screw fastening, and the like.

Japanese Patent No. 3503007

  By the way, although the balance weight made of lead can be manufactured relatively easily by the cavity of the mold, lead has a tendency not to be used in recent years because it is more toxic than other metals.

  In the manufacturing method described in Patent Document 1, there is no relation between the drawing process for forming the iron wire in a constant cross-sectional shape and the connecting process for connecting the clip to the weight shaft. However, it is difficult to manufacture, and the manufacturing time per unit becomes relatively long, resulting in high costs. In addition, when connecting the clip to the weight shaft by welding, it is necessary to perform welding that requires relatively skill, and when the clip is connected to the weight shaft with an adhesive, the connection strength of the clip is welded. When the clip is connected to the weight shaft by caulking, it is necessary to perform caulking after forming the caulking protrusion in a process different from the drawing process. When connecting the clip to the weight shaft by screw tightening, it is necessary to perform screw tightening work after drilling the weight shaft, and it is difficult to easily perform high-strength connection in any connection process. there were.

  The present invention has been made in view of such circumstances, and the main object is to form a weight shaft by a lower mold and an upper mold, and then fix the clip to the weight shaft by caulking, so that the clip has high strength. An object of the present invention is to provide a manufacturing method capable of easily manufacturing a fixed balance weight by pressing.

  Another object is to form a flat receiving surface on which the clip is placed, a caulking protrusion, and an annular groove in which the peripheral edge of the protrusion is recessed from the flat receiving surface on the weight shaft, and caulking processing. It is an object of the present invention to provide a manufacturing method that can sometimes make a part of a clip bite into an annular groove and make the fixing by caulking even stronger.

  Another object is to provide a manufacturing method in which a weight shaft manufactured by pressing can be bent by pressing.

  A balance weight manufacturing method according to the present invention includes a weight shaft for adjusting a weight balance of a wheel for a wheel, and a clip for attaching the weight shaft to a rim portion of the wheel wheel, the clip being a longitudinal length of the weight shaft. A method of manufacturing a balance weight fixed in the middle of a direction, wherein a lower mold on which a shaft material is placed, a molding surface facing a receiving groove of the lower mold, and a molding protruding from a part of the molding surface An upper die having a convex portion and a molding concave portion that is recessed at the center of the molding convex portion is prepared, and a shaft material is placed in the receiving groove of the lower die, and the upper die is lowered to form the shaft raw material. A weight shaft having a flat receiving surface and a protrusion protruding from a central portion of the flat receiving surface is formed on a part of the peripheral surface of the flat plate, and a clip having a hole is formed on the flat surface of the weight shaft in the receiving groove. Place the protrusion into the hole Type, characterized by fixing the clip is crimped by crimping the distal end of the projection to the weight axis.

  In this invention, after placing the shaft material in the receiving groove of the lower mold, the upper mold is lowered, so that a flat receiving surface and a center of the flat receiving surface are formed on a part of the peripheral surface of the shaft material. A weight shaft having a protrusion protruding from the portion can be formed, a clip is placed on the flat receiving surface of the weight shaft, the protrusion is inserted into the hole of the clip, and the tip end portion of the protrusion is crimped Because the clip can be fixed to the weight shaft by using this method, the balance weight can be manufactured. Compared with the balance weight manufactured by connecting processing such as drawing and welding, the balance weight with the clip fixed at high strength can be made inexpensive. It can be manufactured and the unit price of the balance weight can be reduced.

In the balance weight manufacturing method according to the present invention, the lower mold has a second molding convex portion at a position facing the molding concave portion in the receiving groove, and the upper mold is formed of the molding concave portion. The edge portion has an annular convex portion protruding from the molding convex portion.
In this invention, the second mold convex portion of the lower mold allows the portion facing the projection of the weight shaft to be depressed in the projection direction, and the projection can be shaped, so that the projection can be firmly fixed by caulking, In addition, since the annular protrusion of the upper mold can form an annular groove deeper than the flat receiving surface between the flat receiving surface of the weight shaft and the protrusion, the edge of the clip hole can be used when the protrusion is caulked. The portion can be bitten into the annular groove, and the fixing of the protrusion by caulking can be further strengthened.

Further, the balance weight manufacturing method according to the present invention is characterized in that, after the crimping process, both end portions of the weight shaft are pressed in a direction intersecting the longitudinal direction to curve the weight shaft into an arc shape. To do.
In the present invention, even when the weight shaft whose weight is set by the length is curved along the periphery of the rim portion of the wheel for the wheel, the weight shaft can be simply curved by pressing. It is possible to reduce the cost of balance weight which is relatively heavy and relatively long.

  According to the present invention, the weight shaft can be formed from the shaft material by pressing with the lower die and the upper die, and the clip is placed on the flat receiving surface of the weight shaft and the clip is caulked in the hole. Since the protrusion can be inserted and the clip can be fixed to the weight shaft by caulking the tip of the protrusion, a balance weight in which the clip is fixed with high strength can be manufactured at low cost, and the unit weight of the balance weight can be reduced. Can be reduced.

  Further, according to the present invention, the projection can be shaped by the second molding convex portion of the lower mold, the fixing of the projection by caulking can be strengthened, and the weight shaft between the flat receiving surface and the projection, An annular groove deeper than the flat receiving surface can be formed, and a part of the clip can be eaten into the annular groove, and the fixing of the protrusion by caulking can be further strengthened.

  Further, according to the present invention, the weight shaft whose weight is set according to the length can be easily curved by pressing, and the cost of the relatively heavy and relatively long balance weight can be reduced.

It is a perspective view which shows the structure of the balance weight which concerns on this invention. It is a disassembled perspective view which shows the structure of the balance weight which concerns on this invention. It is a bottom side perspective view of the weight shaft showing the configuration of the balance weight according to the present invention. It is a vertical front view which shows the structure of the balance weight which concerns on this invention. It is a top view which shows the structure of the balance weight which concerns on this invention. It is a vertical side view which shows the structure of the balance weight which concerns on this invention. It is a perspective view which shows the structure of the shaft raw material of the balance weight which concerns on this invention. It is process drawing which shows the balance weight processing process which concerns on this invention. It is a disassembled perspective view which shows the other structure of the balance weight which concerns on this invention. It is a bottom side perspective view of a weight shaft showing other composition of the balance weight concerning the present invention. It is the expanded vertical side view which shows the other structure of the balance weight which concerns on this invention. It is process drawing which shows the other process of the balance weight which concerns on this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
Embodiment 1
1 is a perspective view showing the structure of the balance weight, FIG. 2 is an exploded perspective view showing the structure of the balance weight, FIG. 3 is a bottom perspective view of the weight shaft showing the structure of the balance weight, and FIG. 4 is a structure of the balance weight. FIG. 5 is a plan view showing the configuration of the balance weight, FIG. 6 is a vertical side view showing the configuration of the balance weight, and FIG. 7 is a perspective view showing the configuration of the shaft material.

  In the balance weight A, a weight shaft 2 having a flat receiving surface 22 and a substantially oval protrusion 23 protruding from the central portion of the flat receiving surface 22 and a long hole 31 corresponding to the protrusion 23 are formed in the central portion in the longitudinal direction. A fixed plate portion 32 and a clip 3 having a holding plate portion 33 connected to the fixed plate portion 32 and holding a rim portion of a wheel for a wheel. The clip 3 is fixed to the flat receiving surface 22 of the weight shaft 2. Has been.

  The weight shaft 2 is formed by pressing the shaft material 1 shown in FIG. The shaft material 1 is formed such that an iron wire having a round cross section with a prescribed diameter is cut into a prescribed length by header processing, and a cut edge or an edge is curved. In addition, the cutting edge or end edge of the shaft material 1 may not be curved.

The weight shaft 2 and the clip 3 are formed by pressing.
FIG. 8 is a process diagram showing the processing steps of the balance weight A.
The weight shaft 2 is formed by the following machining process.
(1) From the lower die 4 having a substantially oval receiving groove 41 on which the shaft material 1 having curved edges at both ends is placed, a forming surface 51 facing the receiving groove 41, and a central portion of the forming surface 51 The upper mold | type 5 which has the substantially oval shaping | molding recessed part 53 dented in the center part of the shaping | molding convex part 52 which protrudes, and this shaping | molding convex part 52 is used.
(2) The shaft blank 1 is placed in the horizontally long state in the receiving groove 41 of the lower mold 4.
(3) Lower the upper die 5 and press the two circumferential directions of the peripheral surface of the shaft blank 1 flatly by the molding surface 51 and the receiving groove 41 to form the rough surfaces 21 and 21, and the molding convex portion 52, the flat surface 21 that is depressed in the central portion in the longitudinal direction is pressed to form a flat receiving surface 22 that is recessed from the rough flat surface 21, and the concave portion 53 is formed in the central portion of the flat receiving surface 22 from the rough flat surface 21. A substantially oval projection 23 that protrudes slightly outward is formed.
The clip 3 is formed by the following processing process.
(4) A band of a special iron plate having a thickness of 1.0 mm is bent in a thickness direction from one edge of the fixed plate portion 32 and a rectangular fixed plate portion 32 having a long hole 31 by progressive pressing, The clip 3 having the folded holding plate portion 33 is formed. The formed clip 3 is heat-treated and processed to a hardness having an appropriate spring property. A plurality of types of clips 3 having different weights for aluminum wheels and a plurality of types having different weights for steel wheels are formed.
(5) The fixed plate portion 32 of the clip 3 is placed on the flat receiving surface 22 of the weight shaft 2 taken out from the receiving groove 41 of the lower mold 4, and protrudes into the long hole 31 formed in the fixed plate portion 32. 23 is inserted. The flat receiving surface 22 is recessed deeper than the thickness of the clip 3.
(6) The front end of the projection 23 is crimped by caulking with a press machine, the fixing plate 32 is pressed against the flat receiving surface 22, the clip 3 is fixed to the weight shaft 2, and the balance weight A is formed. The crimped protrusion 23 has a height equal to or less than the rough plane 21.
(7) The weight shaft 2, which is relatively heavy and longer than a predetermined length, presses both ends of the weight shaft 2 in a direction crossing the longitudinal direction by pressing, and the weight shaft 2 is outside the rim portion of the wheel for the wheel. The weight shaft 2 is bent into an arc shape so as to correspond to the diameter.
(8) Apply anti-rust treatment to balance weight A.

  The weight shaft 2 and the clip 3 of the balance weight A manufactured as described above are formed by pressing with a press machine, and the clip 3 is fixed to the weight shaft 2 by caulking with a press machine. Since this is also a pressing process, the balance weight A in which the clip is fixed with high strength can be easily manufactured, and the cost of the balance weight A can be reduced.

  In addition, a long hole 31 is formed in the fixed plate portion 32, and the clip 3 is fixed to the weight shaft 2 by caulking of the protrusion 23 fitted in the long hole 31, so that the clip 3 is accurately positioned with respect to the weight shaft 2. Can be easily performed, and the fixing strength of the clip 3 can be increased.

Embodiment 2
9 is an exploded perspective view showing another configuration of the balance weight, FIG. 10 is a bottom perspective view of the weight shaft showing another configuration of the balance weight, and FIG. 11 is an enlarged longitudinal side view showing another configuration of the balance weight. FIG. 12 is a process diagram showing another processing process of the balance weight.

  The manufactured balance weight A has a recess 24 at a position facing the projection 23 of the other rough plane 21 on the weight shaft 2, and a flat receiving surface between the flat receiving surface 22 and the protrusion 23 of the weight shaft 2. There is an annular groove 25 deeper than 22, and the edge of the long hole 31 of the fixing plate portion 32 bites into the annular groove 25 when the projection 23 is caulked, and the clip 3 is fixed.

The processing steps are the same as in the first embodiment, but a part of the lower mold 4 and a part of the upper mold 5 are different.
In the processing step (1), a substantially rectangular second molding convex portion 42 is projected from the receiving groove 41 at a location facing the molding concave portion 53 in the lower mold 4. The upper die 5 having a molding surface 51 that faces the receiving groove 41, a molding convex portion 52 that protrudes from the central portion of the molding surface 51, and a substantially oval molding concave portion 53 that is recessed in the central portion of the molding convex portion 52. An annular convex portion 54 is provided so that an edge portion of the molding concave portion 53 protrudes from the molding convex portion 52.
In the processing step (3), the rough surfaces 21 and 21, the flat receiving surface 22 and the protrusion 23 are formed, and an annular groove 25 deeper than the flat receiving surface 22 is formed between the flat receiving surface 22 and the protrusion 23. In addition, a recess 24 is formed at a location facing the protrusion 23 of the rough plane 21 on the weight shaft 2. The recess 24 is recessed on the side opposite to the projection 23 of the weight shaft 2 toward the projection 23, so that the projection 23 can be shaped.
In the processing step (6), when the tip of the projection 23 is crimped by pressing with a press machine and the fixing plate 32 is pressed against the flat receiving surface 22, the edge of the long hole 31 of the fixing plate 32 is formed in the annular groove 25. The fixing plate portion 32 can be further firmly fixed by caulking into the protrusion 23 and caulking.
Since the other processing steps and the configuration and operation of the balance weight A are the same as those of the first embodiment, the same processing steps and the same parts are denoted by the same reference numerals, and the detailed description and description of the operational effects are omitted. To do.

1 Shaft material 2 Weight shaft 22 Flat receiving surface 23 Protrusion 25 Annular groove 3 Clip 31 Long hole (hole)
4 Lower mold 41 Receiving groove 42 Second molding convex part 5 Upper mold 51 Molding surface 52 Molding convex part 53 Molding concave part 54 Annular convex part

Claims (3)

  A weight shaft for adjusting the weight balance of a wheel for a wheel and a clip for attaching the weight shaft to a rim portion of the wheel for a wheel are manufactured, and a balance weight is manufactured in which the clip is fixed in the middle in the longitudinal direction of the weight shaft A lower die on which the shaft material is placed, a molding surface facing the receiving groove of the lower die, a molding convex portion protruding from a part of the molding surface, and a central portion of the molding convex portion An upper die having a recessed molding recess is prepared, a shaft material is placed in the receiving groove of the lower die, and the upper die is lowered to form a flat receiving surface on a part of the peripheral surface of the shaft material. And a weight shaft having a protrusion protruding from the center portion of the flat receiving surface, and a clip having a hole is placed on the flat receiving surface of the weight shaft in the receiving groove so that the protrusion is Fit into the hole and crimp the tip of the protrusion Method of manufacturing a balance weight, characterized in that fixed to the weight axis said clip Te staking.   The lower mold has a second molding convex part at a position facing the molding concave part in the receiving groove, and the upper mold is an annular convex part in which an edge portion of the molding concave part protrudes from the molding convex part. The method for producing a balance weight according to claim 1, comprising a portion.   The method for producing a balance weight according to claim 1 or 2, wherein after the crimping process, both end portions of the weight shaft are pressed in a direction crossing the longitudinal direction to curve the weight shaft into an arc shape.

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