JP2002210743A - Manufacturing method for molding die of resin product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the efficiency of manufacturing a molding die of a resin product by reducing a working time, a required cost or the like during manufacturing the molding die and ensure that highly precise channeling is achieved in terms of working area roughness and working precision. SOLUTION: When a rib molding channel (m) is fabricated out of the molding area Gp of the molding die G for a resin bumper, the channel (m) is cut using a taper end mill 1 of such a shape as to coincide with the shape of the channel (m). Further, when the molding area Gp is cut in the depth direction, a fabrication pass descending obliquely is set. Consequently, it is possible to achieve a finer channeling. In addition, the finish quality of the fabricated area is improved by fabricating the side wall of the channel in a down cut fashion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing a mold for manufacturing a resin pumper on which a masking jig for painting can be set.

[0002]

2. Description of the Related Art Conventionally, as a technique for forming a groove for forming a rib in a mold for forming a resin product having a rib, for example, a technique as disclosed in Japanese Patent Application Laid-Open No. Hei 7-108568 is known.
In this technique, a metal burying space is formed in a mold using a ball mill, and a metal burial having a step on a side surface is buried in the metal burying space, thereby forming a side step portion of the metal burial. The rib-forming groove is formed by the method, but the buried metal buried space shown in this technology is a relatively wide and shallow groove processing, for example, a masking jig for applying paint to a resin bumper is installed. It cannot be applied to the machining of a groove that is deep from the surface adjacent to the upright wall portion and that requires precision, such as a rib groove for forming a groove.
For this reason, such a rib groove for mounting a masking jig is formed by machining a portion other than the groove by machining or the like, and then forming the same on a molding surface of a mold G as shown in FIG. The groove is formed by using the electrode 51 and performing electric discharge machining.

[0003]

However, the method of machining a groove separately by electrical discharge machining after machining is not only a long machining time, but also wasteful in electrode fabrication and the like, and causes a cost increase. At the same time, there is a problem that the surface roughness of the processed surface is rough, and it takes a lot of man-hours to increase the surface roughness. In addition, there is also a problem that the processing accuracy decreases because the electrode 51 is worn away every time processing is performed.

Accordingly, an object of the present invention is to reduce the processing time, required cost, and labor of the work to improve the efficiency, and to perform the groove processing with good surface roughness and processing accuracy of the processed surface. .

[0005]

In order to achieve the above object, according to the present invention, a groove having a shape in which a groove width is reduced in a depth direction is formed on a part of a molding surface adjacent to an upright wall portion. In a method of manufacturing a resin product molding die, portions other than the groove on the die molding surface are formed by machining, and then the groove is formed by down-cutting using a taper end mill.

[0006] For example, the shape of the outer peripheral side surface of the tapered end mill is formed in a tapered shape inclined in a taper direction,
Downcutting both side surfaces of the groove with the side outer peripheral blade enables direct processing of the groove in which the groove width narrows in the depth direction, greatly reducing the process compared to electric discharge machining. In addition, the cost can be reduced, and the quality of the machined surface can be improved. In addition, shaping by down-cut processing suppresses chatter during processing as compared with up-cut processing, further improves the quality of the machined surface, and can extend the life of the cutting edge and reduce the feed power. There are advantages such as.

Further, in the present invention, when a groove is machined, a machining path line which is obliquely lowered when cutting in the depth direction is set.

[0008] That is, when cutting in the direction perpendicular to the depth direction, the accuracy is reduced unless the rigidity of the end mill is increased, and when trying to increase the rigidity of the end mill, it is impossible to machine a thin groove. become. Therefore, by setting a processing path line that goes down diagonally, a finer groove processing can be performed, and the processing accuracy is improved.

It is preferable that the resin product is a bumper part and the groove to be processed is a groove for forming a rib for mounting a masking jig on the bumper part.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an explanatory view of a resin pump, FIG. 2 is an explanatory view of a resin bumper molding die, FIG. 3 is an explanatory view of an example of a taper end mill, FIG. 4 is an explanatory view of groove processing by a taper end mill, and FIG. FIG. 4 is an explanatory view of the down cut as viewed from the plane direction, and FIG. 6 is an explanatory view of a method of cutting obliquely in the depth direction.

The method for producing a resin product molding die according to the present invention is applied to, for example, the production of a resin mold for molding a resin bumper P as a resin product as shown in FIG. The periphery is painted except for the central radiator portion, at which time a masking jig (not shown) is attached to the central unpainted portion.

Therefore, in order to form a rib for mounting a masking jig on such a resin bumper P, as shown in FIG. 2, a rib forming groove m adjacent to the upright wall portion h is formed on the forming surface Gp of the mold G. Is provided, and such a rib forming groove m is provided with an inclination on both wall surfaces in order to ensure the removability of the molded product.
The shape is such that the groove width on the front side is wider than the groove width on the back side of the groove. As described above, the rib forming groove m
Is located at a deep position adjacent to the standing wall portion h, has a relatively narrow groove width, and requires the precision of the groove. Therefore, in the related art, it is formed by electric discharge machining as shown in FIG.

[0013] For this reason, conventionally, the number of manufacturing steps is increased, which is troublesome and causes a cost increase. Therefore, in the present invention, this rib forming groove m is formed by a tapered end mill 1 as shown in FIG. In addition, the number of manufacturing steps and cost are reduced.

The tapered end mill 1 has an end surface cutting edge 1a and an outer peripheral edge 1b on an end surface and an outer peripheral surface, and the outer peripheral surface is inclined in a taper direction in accordance with the inclined shape of the wall surface of the rib forming groove m. The inner wall of the rib forming groove m can be directly processed by the outer peripheral blade 1b. Further, the length of the tapered end mill 1 is configured to have rigidity with a minimum processing length.

As shown in FIG. 6, the taper end mill 1 is first cut obliquely with respect to the vertical direction, and then is moved in a constant horizontal direction so that the groove wall surface is formed as shown in FIG. After processing with the blade 1b and finishing at a certain depth, the taper end mill 1 is again cut obliquely with respect to the vertical direction, and then moved in the horizontal constant direction to process the groove wall surface with the outer peripheral blade 1b. By repeating this, a rib forming groove m having a required depth is formed.

Here, when the groove wall surface is processed by the outer peripheral blade 1b, as shown in FIG. 5, it is processed by down-cut processing so that the relative movement direction and the rotation direction of the workpiece are the same. I have. By cutting in this way, the cutting surface quality is improved without chattering compared to the up-cutting, the life of the cutting edge is prolonged, and advantages such as reduced feed power are obtained. Can be done.

Further, as shown in FIG. 6, by cutting obliquely from the vertical direction when cutting into the depth of the groove, the rigidity of the tapered end mill 1 does not need to be increased unnecessarily. Grooves can be made thinner than end mills.

Incidentally, in this embodiment, the shape of the tapered end mill 1 is configured to match the shape of the rib forming groove m shown in FIG. 2, and the inclination angle of the outer peripheral blade 1b is set as shown in FIG. The inclination angle of the groove wall of the molding groove m is the same as that of the groove, and the processing is performed by NC processing based on NC control.

Next, a method of manufacturing the mold G will be described. First, a portion other than the rib forming groove m in the forming surface Gp of the mold G is formed by machining such as a ball mill, and then the rib forming groove m is processed by the taper end mill 1. At this time, after the taper end mill 1 is cut obliquely to the vertical direction, it is moved in a constant horizontal direction to machine the groove wall surface by downcut, and this is repeated to gradually increase the depth of the groove. Is set, and the NC control is performed on the processing path to finally form a rib forming groove m having a desired depth. Incidentally, the roughness of the machined surface cut by the taper end mill 1 by the above method is 11
μmRmax, surface roughness 25μ
It was confirmed that it was significantly improved as compared with mRmax.

The present invention is not limited to the above embodiment. Those having substantially the same configuration as those described in the claims of the present invention and exhibiting the same operation and effect belong to the technical scope of the present invention. For example, the specific shape of the tapered end mill 1 is an example.

[0021]

As described above, the method for producing a resin product molding die according to the present invention is suitable for producing a resin product molding die having a groove having a shape in which a groove width is narrowed in a depth direction. After the parts other than the grooves are formed by machining, the grooves are directly formed by down-cutting using a taper end mill, which significantly reduces the process compared to conventional electric discharge machining and reduces costs. And
Moreover, the quality of the machined surface is improved. Also, in the groove processing, if a processing path line that is obliquely lowered when cutting in the depth direction is set, a finer groove can be processed with high accuracy. It is preferable that such a resin product be a bumper part.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a resin pump.

FIG. 2 is an explanatory view of a resin bumper molding die.

FIG. 3 is an explanatory view showing an example of a tapered end mill.

FIG. 4 is an explanatory view of groove processing by a taper end mill.

FIG. 5 is an explanatory view of a down cut as viewed from a plane direction in FIG. 4;

FIG. 6 is an explanatory diagram of a method of cutting obliquely in a depth direction.

FIG. 7 is an explanatory view of a conventional electric discharge machining.

[Explanation of symbols]

1: taper end mill, 1b: outer peripheral edge, G: mold, Gp
... molding surface, P ... resin bumper, h ... standing wall part, m ... rib forming groove.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasushi Takeshita 1-10-1 Shin-Sayama, Sayama City, Saitama Prefecture Inside Honda Engineering Co., Ltd. (72) Inventor Shinichi Sawai 1-1-10-1, Shin-Sayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. F-term (reference) 4F202 AH24 CA11 CB01 CD18 CK11

Claims (3)

[Claims] 1. A method for manufacturing a resin product molding die, wherein a groove having a shape in which a groove width is reduced in a depth direction is formed on a part of a die molding surface adjacent to an upright wall portion. Manufacturing a mold for resin product molding, comprising: a step of forming a portion other than a groove on the mold forming surface by machining, and a step of forming the groove by down-cutting using a taper end mill. Method. 2. The method for manufacturing a resin product molding die according to claim 1, wherein, when the groove is machined, a machining path line that is obliquely lowered when cutting in a depth direction is set. Manufacturing method of resin product molding die. 3. The method for manufacturing a resin product molding die according to claim 1, wherein the resin product is a bumper part, and the groove forms a rib for mounting a masking jig on the bumper part. A method for producing a resin product molding die, characterized in that it is a groove for forming.