JPS61226138A - Molding method for metallic mold including core - Google Patents

Abstract

PURPOSE:To reduce a stage for operation and to produce a metallic mold having good quality by preparing an integral type casting connected with a core by means of a rib to a metallic mold body for press molding and working the datum plane then positioning the mold, subjecting the same to prescribed finish working and cutting off the rib. CONSTITUTION:A pattern for the metallic casting mold for press molding is attached with the body part and the core part by the rib which are then united in the exact relative relation to form the integral type metallic mold for casting. The datum plane of such metallic mold is worked and thereafter the mold is positioned on the basis of the datum plane and the forming part of the metal lic mold is machined. The rib is cut away after the completion of the finish working, by which the metallic mold including the core is obtd. The stage for operation is reduced and the metallic mold having the exact relative position and good quality is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding method for a mold, and more particularly to a large mold, for example, a press mold body for forming a side panel of an automobile body, and a front door mold body for forming a side panel of an automobile body. A mold forming method that makes it possible to integrally cast and mold the mold and the core that defines the opening for the rear door, and to automatically perform the finishing process of the mold thus cast. Regarding.

BACKGROUND ART Generally, side panels constituting an automobile body are cut and formed using a press mold. That is, the side panel of a passenger car is formed by simultaneously cutting a mold body having the panel shape and a movable core for defining an opening for attaching a door portion. Therefore, in order to obtain a good side panel as a product, the mold body and the core must be molded with extreme precision (and smoothness).

Therefore, a molding method for forming a mold body and a core according to the prior art is illustrated in FIGS. 1 to 3.

First, the mold body 2, the first core 4, and the second core 6 are individually cast by a full mold method using polystyrene, for example (see FIGS. 1A to 1C). One side surface portion 8 of the mold body 2 is formed to bulge upward by a predetermined amount, and protrusions 9a and 9b are provided at both end edges of this surface portion 8. An opening 10 having the shape of an outer frame of a side panel of a vehicle body is defined within the mold 2. On the other hand, the first core 4 has the shape of an outer frame of a front door, and is bulged to form a surface portion 12, and protrusions 13a and 13b are formed at both end edges thereof. Note that an opening is provided in the center of the first core 4 to reduce the weight. Furthermore, the outer circumferential portion of the second core 6 is similarly formed to correspond to the outer frame shape of the rear door, and the second core 6 has a surface portion 14 and protruding portions 16a, 16b formed in a bulging manner. be done.

Therefore, FIGS. 2A to 2C show the finishing process of the mold body 2 constructed as described above. That is, the mold body 2 is suspended by a crane or the like and placed in a parallel state, and first,
The protrusions 9a and 9b are processed to be smooth (see FIG. 2C).

Next, the mold body 2 is rotated 180° to form the protrusion 9a,
While the mold body 2 is supported by the mold body 9b, the upper surface of the mold body 2 corresponding to the surface portion 8 is milled. As a result, a smooth reference surface 18 is formed (second
(see figure). Furthermore, after rotating the mold body 2 by 180 degrees and fixing this reference surface 18 in a predetermined position, for example, on the bed of a machine tool, the surface portion 8 and the side surface portion of the mold body 2 are etc. to make it extremely smooth.

Then, predetermined holes and the like are bored as necessary (see FIG. 2C).

On the other hand, FIGS. 3A to 3C show the finishing process of the second core 6.
First, after suspending the second core 6 in a parallel state using a crane or the like, the protrusions 16a and 16b are smoothed (second
(See Figure C). Next, the second core 6 is rotated by 180 degrees, and the second core 6 is supported by the protrusions 16a and 16b, and is milled to form a smooth reference surface 20 (see FIG. 3). ), further, the second core 6 is 18
The reference surface 20 is rotated by 0' and positioned and fixed on, for example, the bed of a machine tool, and the surface portion 14, side portions, etc. are smoothed using a ball end mill, milling cutter, etc. (see FIG. 3C). Note that the first core 4 for the front door is also processed in the same manner as the finishing process of the second core 6 shown in FIGS. 3A to 3C.

After finishing the mold body 2, the first core 4, and the second core 6 into predetermined shapes in this way, each core 4.6 is placed at a predetermined position in the mold body 2, for example. , is positioned in a movable state via a spring or the like. Therefore, an iron plate (not shown) is arranged, and a side panel for a vehicle body having a predetermined shape is formed by press forming via this mold body 2 and each core 4.6.

By the way, in the above-mentioned conventional technology, after the mold body and the core are individually cast and molded, they are processed individually, so the total number of processing steps is extremely large, and the work takes a lot of time.

Moreover, since each component is processed individually and independently, it is difficult to make the relative quality of each component uniform. Therefore, the reality is that the mold body and core are refinished and delicate adjustments are made to ensure that there are no irregularities in the quality of the product that is press-formed through the mold body and core. It is. In other words, with the conventional technology, it takes time to process the completed mold body and core, and the finishing work is extremely complicated, making it difficult to perform mass production. This caused the inconvenience of being difficult. Furthermore, since the mold body and core are cast separately, each molded product requires careful work with the same level of skill, so the space for molding work is also large (occupying less space). Difficulties were pointed out, such as the need to do this and the need for a large number of workers.

The present invention has been made to overcome the above-mentioned disadvantages, and by integrally casting the mold body and the core, the mold body and the core can be obtained extremely easily and in a short time. We have created a molding method for molds including cores that can ensure uniform quality of each molded product when finishing them, and that can easily automate the processing work. The purpose is to provide.

In order to achieve the above object, the present invention includes a first step of connecting a press molding die body and a press molding core by ribs to integrally form a cast body, and a step of connecting a press mold body and a press molding core by a rib, and a step of connecting a press mold body and a press molding core by a rib to form a cast body integrally. a second step of performing machining, a third step of positioning the reference plane formed by the reference machining and applying a predetermined finishing process to the cast body, and ribbing the mold body and core of the cast body. and a fourth step of separating and cutting by cutting out.

Next, a method for molding a mold according to the present invention will be described in detail below with reference to preferred embodiments and the accompanying drawings.

In FIG. 4, reference numeral 30 indicates a cast body, and the cast body 30 includes a mold body 32, a first core 34, and a second core 36, which are integrally cast.

One side surface portion 38 of the mold body 32 bulges upward and has a curved shape, and a pilot hole 40 is formed at a corner thereof.
A to 40d are bored, and a protrusion 42a is provided between each pilot hole 40a and 40b, and between 40c and 40d.
, 42b are formed, respectively. Furthermore, a predetermined opening 44 defined in accordance with the shape of the side panel of the vehicle body is provided in the center of the mold body 32, and the cores 34, 36 are formed within this opening 44. . The first core 34 and the second core 36 have ribs 46a to 46 having predetermined dimensions.
The curved surface portions 48.50 of each core 34.36 are integrally connected to the mold body 32 via Il.
Similar to the surface portion 3 of the mold body 32, the surface is inclined to define a curved surface.

The cast body 30 configured as described above is formed by casting, for example, by a full mold method.

That is, a mold (not shown) made of polystyrene is formed in the same shape as the cast body 30, and this mold is buried in casting sand.Next, if the molten metal is directly poured into this mold, it will melt at a high temperature. Molten metal easily burns off polystyrene. Therefore, this molten metal replaces a mold made of polystyrene, and in the final solidified state, a cast body 30 having the same shape as this mold is obtained. In this case, the polystyrene corresponding to the ribs 46a to 46ffi is melted to define a runner, and is passed through the runner to the core 34.3.
The molten metal to form 6 is injected into the center of the mold. Note that the molten metal that solidifies in the runner will eventually form the rib 46a.
It is understood that the number is 461 to 461.

The mold body 32 and each of the cores 34, 36 thus cast and formed are finished into a predetermined shape through the processing steps shown in FIGS. 5a to 5C.

First, the cast body 30 is positioned in a parallel state using a crane or the like, and then the protrusions 42a and 42b are processed to be smooth. Therefore, the cast body 30 is rotated 180″' so that the protruding portion 42
With this cast body 30 supported by 42b and 42b, milling is performed on the surface corresponding to the surface portion 38 to form a smooth reference surface 52 (see FIG. 5a).Next, the cast body 30 is After rotating 180@ and positioning and fixing this reference surface 52 to the bed of a machine tool (not shown), etc., the mold body 3
2 and the surface portion 4 of each core 34,36.
8. Process 50 and each side part using a ball end mill, milling cutter, etc. (see Fig. 5). Note that predetermined holes are machined at the corners of the cast body 30 to define the pilot holes 40a to 40d.

Next, the cast body 30 is positioned and arranged on a pallet (not shown) with reference to each of the pilot holes 40a to 40d, and a finishing process is applied to the wall surface defining the opening 44 in the mold body 32. After that, the mold body 32, core 34 and 3
By cutting the ribs 46a to 46ffi existing between the mold body 32 and the core 34, 36 of a predetermined shape.

Therefore, after fixing the mold body 32 formed in this way to a predetermined press machine (not shown), the core 34.
6 is mounted in a movable state via, for example, a spring, a press plate is placed on the upper surface of the mold body 32 and the cores 34 and 36, and this is press-molded.

In this way, after the mold body 32 and the respective cores 34 and 36 are integrally cast and molded, the respective parts, that is, the mold body 32 and the cores 34 are further processed into one body. ．．
There is no variation in the relative quality of 36. Moreover, since the mold body 32 and each of the cores 34 and 36 can be molded and finished in the same process, the work process is simpler than in the conventional technology, in which each was individually cast and processed. The effect is extremely simple and can be achieved in a short time.

As described above, according to the present invention, since the mold and the core are integrally cast and molded, the respective work steps can be shortened, and a mold with excellent quality can be obtained extremely easily. Therefore,
It also facilitates the automation of the mold manufacturing process, and has the advantage of being an effective means especially when molds and cores are formed in mass production.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments. For example, the shape and number of ribs connecting the mold and the core may be Of course, various improvements and changes in design are possible without departing from the gist of the present invention, such as by appropriately selecting the type, core size, number of cores, etc. .

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1A to C are plan views of a conventional mold and core formed by casting, FIGS. 2A to C are process diagrams showing a method of molding a mold according to the prior art, FIGS. 3a to 3C are process diagrams showing a method for molding a core according to the prior art, FIG. It is a process diagram of the molding method of a child. 30... Cast body 32... Mold body 34.36
Pad core 38...Surface portion 40a-40d...Bi-loft hole 44...Opening portion 46a-46J...Rip 48.
50...Surface portion 52...Reference surface Patent applicant Honda Motor Co., Ltd. Fig, 4 Fig, 3 (C) Procedural Dispute Report (C) February 5, 1985 1, Indication of the case 1985 Patent layer No. 672
No. 20 No. 2, Title of the invention Method for molding molds including cores 3, Relationship with the amended case Patent applicant address 2-1-1 Minami-Aoyama, Minato-ku, Tokyo Name Honda Motor Co., Ltd. 4 , Agent 1, amends the claims from page 1, line 4 of the specification to page 2, line 2 as follows. ``2. Claims (1) A first step of connecting a press molding die body and a press molding core by a rib to integrally form a cast body, and performing standard processing on the cast body. a third step of positioning the reference surface formed by the reference processing and applying a predetermined finishing process to the cast body; A method for molding a mold including a core, comprising a fourth step of separating and cutting by cutting out the core. (2) In the method according to claim 1,
The first step is a full mold method using polystyrene, which includes a mold including a core. (3) In the method described in claim 2,
"A method for molding a mold including a core in which the ribs are formed in a runner defined by polystyrene clay that disappears upon injection of molten metal." 2. Section 3 of the Detailed Description of the Invention column of the specification. On the 11th line of the page, correct the statement "...inside mold 2..." to "...inside mold body 2...". 3. Detailed description of the invention in the specification, page 10, item 1θ
In the first line, "... (See Figure 5)," should be corrected to "... (See Figure 5)."

Claims (3)

[Claims] (1) A first method in which a press molding die body and a press molding core are connected by ribs to integrally form a cast body.
a second step of performing standard processing on the cast body;
a third step of positioning the reference surface formed by the reference machining and subjecting the cast body to a predetermined finishing process; and a third step of separating and cutting the mold body and core of the cast body by cutting out ribs. A method for molding a mold including a core, comprising the steps of 4. (2) In the method according to claim 1, the first
The process is a method of forming a mold including a core, which is a full mold method using polystyrene. (3) The method according to claim 2, wherein the ribs are formed in a runner defined by a polysteel roll that disappears when molten metal is poured into the mold.