JPH02211930A - Manufacture of type master model - Google Patents

Abstract

PURPOSE:To improve shape accuracy, surface roughness and surface accuracy by individually manufacturing plate-like frame part forming pieces and blocks for forming profile surface having height lower than that of the frame part forming piece and integrally assembling the frame part forming pieces and the blocks for forming the profile surface. CONSTITUTION:The frame part forming pieces 1, 2 and the blocks 3, 4, 5 for forming the profile surface are individually manufactured, respectively. The frame part forming piece has the shape adding shrinkage ratio of a casting product to the shape corresponding to the frame of a tyre mold and is the bending thin plate-like body. The block for forming the profile surface has low height and the upper face is made to the curved profile surface 6 and the side face 7 is made to jagged shape corresponding to the frame part forming pieces 1, 2. Both of the frame part forming piece and the block for forming the profile surface can be manufactured with a wire electric discharge machining, etc. These parts are fixed with a resist pin 10 and a screw 11 to set them to a box 8. These master models are reversed with gypsum rubber resin, etc., to execute casting of the tyre mold. By this method, the mold can be accurately and easily manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a tire master model used for casting the bone portion of a tire mold.

(Prior art) A tire mold for forming a tire is manufactured by a casting method, in which a bone part for forming grooves on the tire surface is manufactured separately from a mold body having an inner peripheral surface corresponding to the outer shape including the tread surface of the tire. In this case, it is first necessary to create a master model of the tire mold bone in which the tire mold bone is divided into a number of blocks. For this reason, conventionally, as shown in Fig. 2, a block (22) having a surface (21) that is gently curved to match the profile surface of the tire is machined by electric discharge machining to form a block (22) with a shape that corresponds to the bone part of the tire mold. A groove (23) is formed, and a frame part (2
4) with screws (25) or the like to produce a master model of the tire mold bone. However, in this conventional method, it is necessary to form a narrow bag-shaped groove (23) by electrical discharge machining, which results in poor machining stability and a decrease in the accuracy of the bone shape and surface roughness. There was a simple drawback. In addition, polishing takes a long time due to the decrease in surface roughness, and depending on the groove width, polishing is difficult and the rounded part (26) on the bottom surface tends to sag. In particular, it is difficult to polish the groove (23) by tilting it by α. When it is necessary to do so, the positional accuracy and depth accuracy tend to deteriorate.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks and provides a master model for manufacturing tire molds with complex bone shapes with good positional accuracy and depth accuracy. This invention was completed with the aim of providing a method for manufacturing a master model of a tire mold bone that is easy to manufacture and does not cause any problems even when the shape of the bone is tilted.

(Means for Solving the Problems) The present invention, which has been made to solve the above problems, includes a plate-shaped bone forming piece having a shape corresponding to the bone part of a tire mold;
A profile surface forming block for forming the profile surface of the tire mold and a profile surface forming block whose height is lower than the bone section forming pieces are separately produced, and the profile surface forming blocks are placed in the middle and outside of the plurality of bone section forming sections. It is characterized by being assembled into one piece.

(Example) Next, the present invention will be explained in detail with reference to an example shown in FIG.

In the present invention, plate-shaped bone forming pieces (1), (2) and profile surface forming blocks (3), (4), (5) are used.
and are manufactured separately. Bone formation fragments (1), (2
) has a shape corresponding to the bone part of the tire mold multiplied by the shrinkage of the cast product, and in the illustrated example, it is a thin plate-like body with a bent shape. These bone forming pieces (1) and (2) can be manufactured with good shape accuracy and surface roughness by wire electrical discharge machining.

In addition, the surface roughness is good and the polishing allowance is small, which improves overall precision.Furthermore, since it is a single component, polishing is easy and eliminates corner wobbling and uneven tip radius (R). can.

On the other hand, profile surface forming blocks (3), (4),
(5) is shorter than the bone formation pieces (1) and (2), and its upper surface is a curved profile forming surface (6), and its side surface (7) is the bone formation piece (1). , (2). Since these profile surface forming blocks (3), (4), and (5) are also single parts, they can be easily manufactured with high precision by means such as wire electric discharge machining. In particular, in order to incline the bone formation piece (1) by α as shown in the figure, the side surface (7) is
Even if it is necessary to tilt the surface, the machining becomes easy.

As shown in the figure, each of the individually manufactured parts has profile surface forming blocks (3), (4), (5 ), and after adjusting the position W, fix it with the resist bin 0 (D and screw 01), and then attach the box (8).
Set it inside. Although it is preferable to have flat plates (9), (9) as shown in the figure erected inside the box (8), these flat plates (9), (9) may be omitted. If each part is set inside the box (8) and the whole thing is further fixed with screws, etc., a plurality of bone forming pieces (1), (2) will be formed above the curved profile forming surface (6). A master model that stands out is completed,
If this master model is inverted using gypsum rubber resin or the like, it will have the same shape as a conventional master model, and a tire mold can be cast in the same manner as in the conventional method.

(Effects of the Invention) As explained above, the present invention is a method for manufacturing a tire master model by assembling individually produced bone part forming pieces and profile surface forming blocks into one piece.
The following effects can be obtained.

■Unlike conventional methods, the bone formation piece can be processed into a convex shape, so shape accuracy, surface roughness, and surface precision can be improved.

■Also, it becomes easier to polish the bone-forming piece, significantly improving work efficiency, and eliminating wobbling of the corners and unevenness of the tip radius.

■Although the number of parts increases because it is a split type, each part can be manufactured in a separate process, reducing the overall manufacturing time.

■Even in the case of partial design changes or repairs, work is easy as individual parts can be processed.

■It can be easily manufactured even when the bone part is thin and sloped.

As described above, according to the present invention, a bone mask model of a tire mold for a tire with a complicated bone shape can be manufactured with high accuracy and extremely easily, and therefore a tire mold that solves the drawbacks of the conventional tire mold can be produced. As a method for producing a master model of the bone, this method will greatly contribute to the development of industry.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view showing a master model of a conventional tire mold bone. (1), (2): Bone formation piece; (3), (4), (5): Profile surface formation block.

Claims (1)

[Claims] Plate-shaped bone forming pieces (1), (2) for forming the bone of the tire mold, and bone forming pieces (1), (2) with a lower back for forming the profile surface of the tire. The low profile surface forming blocks (3), (4), and (5) are manufactured individually, and the profile surface forming blocks (3) are placed in the middle and outside of the plurality of bone forming pieces (1) and (2). ), (
4) A method for manufacturing a tire master model, characterized by arranging and assembling (5) in one piece.