JPH03216313A - Injection mold - Google Patents

Abstract

PURPOSE:To shorten the manufacturing time by obviating the finishing process and facilitate the manufacturing, by a method wherein a casting frame is arranged, to which resin cast in anticipation of shrinkage of casting resin is stuck and made into a mold part incorporatable into a mold base. CONSTITUTION:A model 3 is fixed by assembling spacers 21, 22 and a casting frame 1A possessing a tapered part 1a. Resin 4 is cast into the model 3, which is cured primarily and then a resin mold 4' is slid downward by running along the tapered part 1a. The same is inverted and a spacer 23 is provided on the circumference of the projected resin mold 4' with a mount 6 and supporting part 6. Resin 7 is cast by extending a casting frame 1B possessing a tapered part 1b, demolding of the model 3 is performed after primary cure and cured secondarily. Then, the finishing process is obviated by a method wherein a mold part comprised by unifying by sticking shrinkage amounts of a resin mold 7' as a core and the resin mold 4' as a cavity close to the tapered parts 1a, 1b by providing them is incorporated into a mold base by making use of also the outside casting frames 1A, 1B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a resin injection mold suitable as a mold for molded products produced in small quantities in a wide variety of products.

(Conventional technology) In the past, injection molds were generally made of metal, but when the molded product is produced in small quantities, the manufacturing period of the injection mold is short and it is easy to handle. Due to these advantages, resins are increasingly being used as injection molds.

8 to 14 show conventional examples of this type. In the conventional method, first, as shown in FIG.
The parting surface forming plate 52 is set in the casting frame 50 provided on the mold, and the model 53 is placed on it.
Thereafter, as shown in FIG. 9, resin 54a is injected and the upper opening is covered with an upper plate 55. Then, as shown in FIG. 10, after curing, the parting surface forming plate 52 and the bottom plate 51 are removed, and the casting frame 5 is
0 was inverted, and as shown in FIG. 11, resin 54b was injected and a mounting plate 56 was provided.

As shown in FIG. 12, after curing, it is turned over and
In addition, the casting frame 50, top plate 55, mounting plate 56, model 53, etc. were removed. In this case, when removing the model 53 from the mold, the model material was heated to soften it if it was made of plastic. Thereafter, as shown in FIG. 13, an ejector bin hole 57 and a cooling water pipe 58 were formed in the core 54B made of resin 54b, and a subur 59 and a cooling water pipe 58 were formed in the cavity 54A by machining.

FIG. 14 shows a state in which the core 54B, cavity 54A, etc. are assembled into the mold base, and in the figure, 60.61
62 is a template plate, 62 is a receiving plate, 63 is a mounting plate, 64 is a spacer block, 65 is an upper ejector plate, and 66 is a lower ejector plate. Further, 67 is an ejector bin, and the mounting plate 63 side is a fixed side, and the opposite side is a movable side.

(Problem to be solved by the invention) However, in the above conventional example, when manufacturing an injection mold,
In FIG. 13, the dashed line indicates the finishing margin, and in order to make the hardened resins 54a and 54b into mold parts such as the width 54A and the core 54B, the six-sided parts must be finished by machining or manual processing. However, manufacturing is complicated, and for this reason, there is a problem in that it must be made thicker to allow for a finishing margin.

The present invention was proposed in view of the above, and its purpose is to provide an injection molding mold that eliminates the need for finishing processing, facilitates manufacturing, shortens manufacturing time and delivery time, and ultimately reduces costs. is to provide.

(Means for solving ti!!) In the present invention, a casting frame is provided in an injection mold made of resin, and the casting resin is poured into the casting frame in anticipation of shrinkage. The above objective is achieved by making a mold part that can be assembled into a mold base by closely adhering the resin.

(Function) As mentioned above, the mold part is formed by bringing the cast resin into close contact with the casting frame in anticipation of shrinkage of the resin, and it can be assembled into the mold base without hexahedral processing. ,
No finishing processing is required.

For this reason, we have made the manufacturing process more flexible and have various advantages, such as shortening the manufacturing time and delivery date.

(Example) Figures 1 to 7 show an example of the present invention.
The injection mold according to the present invention is manufactured as follows.

? That is, as shown in FIG. 1, first, a first casting frame IA for a cavity having a taper 1a on the inside, a first spacer 2l located on both outsides of the bottom, and a first spacer 2l on the inside thereof. A second spacer 2. are assembled to form a cylindrical frame with a bottom, and model 3 is fixed on top of the second spacer 2■. Next, as shown in FIG. 2, a core resin 4 is injected into the assembled frame and placed at room temperature or in a drying oven for primary hardening.

Thereafter, as shown in FIG. 3, each substrate 2.2. is removed and the resin mold 4' formed by hardening the resin 4 is placed in the first
Shift it slightly downward along the taper 1a of the casting frame IA. Next, as shown in FIG. 4, these were inverted, and the mounting base 5 was placed below, and the resin mold 4' was protruded by the support part 6 provided approximately at the center of the mounting base 5. The state is maintained and a third spacer 2 is provided around the protruding portion. This third spacer 2 is located above the first casting frame IA.

Note that the first and second spacers 21 shown in FIG. (2) And this third spacer 23 may be omitted if it can withstand the mold clamping force and molding pressure.

Then, a second casting frame IB for the core, which has a taper 1b in the opposite direction to the taper 1a on the inside, is extended upward.

Then, as shown in FIG. 5, a resin 7 serving as the core is injected and hardened.

Next, as shown in FIG. 6, after the resin 7 has been primarily cured, the third spacer 2 is removed, and the model 3 is demolded and subjected to secondary curing. In this case, the mounting plate 5 and the support part 6 are removed, the resin mold 4 is slightly shifted downward, and the resin mold 7' formed by hardening the resin 7 is also shifted downward, so that the resin molds 4' and 7' are The casting frame IA. where the joint parts are spaced apart and facing each other. It is set to approximately the middle position of 1B. Note that after the secondary curing, the third spacer 2 may be removed and the model 3 may be demolded. In this way, the resin mold 7' functions as a core, the resin mold 4' functions as a cavity, and the resin molds 4', . A mold portion in which the shrinkage portion 7' is brought into close contact with the tapers Ia, lb of each casting frame IA, IB and integrated therewith is assembled into a mold base as shown in FIG. In this case, the first and second casting frames IA and IB located outside the resin mold 4'7' are also used as mold parts, eliminating the need for finishing work as in the past. Before assembly into the mold head, a spool 8 is formed in the resin mold 4', and an ejector pin hole is formed in the resin mold 7' by machining. That is, 9 in FIG. 7 is an ejector pin provided in the ejector pin hole,
The base plate side thereof extends downward through the receiving plate work 2, and is supported by the upper ejector plate 1o.
] is provided.

In addition, 13 in the figure is a base, and a spacer cloth 14 is erected on the upper outer part of this base, and the receiving plate 1 is placed above it.
2 is provided. A template 15 is provided on the receiving plate 12, and on top of it a suitable number of at least one base plate 16 is laminated. A mold plate l8 is provided through the mold plate 17, and a mold part is provided in the mold plate 15.18. Note that the spacer 16. The inner end of 17 is the first and second casting frame I.
A. It is located between IB. Moreover, a mounting plate 19 having a spool 8a communicating with the spool 8 in the center thereof is provided on the upper part of the template l8. Further, the lower ejector plate 11 is provided above the base l3, and a cylinder rond (not shown) is connected to the ejector plate through a hole 13a formed in the center thereof, as is well known.
After the molded product is molded and the mold is opened, the ejector bin 9 is driven via a cylinder to remove the molded product.

(Effects of the Invention) As described above, according to the present invention, a casting frame is provided in an injection mold made of resin, and the casting resin is poured into the casting frame in anticipation of shrinkage. Since it is constructed as a mold part that can be assembled into a mold base by closely adhering the resin, it does not require hexahedral processing for finishing, which makes manufacturing easier, reducing manufacturing time, and therefore shortening delivery time. This has the effect of reducing costs.

[Brief explanation of drawings]

Figures 1 to 7 show a first embodiment of the present invention, in which Figures 1 to 3 show the manufacturing process of the cavity, Figures 4 and 5 show the manufacturing process of the core, and Figure 6 shows the finished product. The raised mold part, Fig. 7 is an explanatory diagram showing the state in which it is assembled into the mold head, and Figs. 8 to 14 are explanatory diagrams of the conventional manufacturing process. IA...first casting frame, 1B...second casting frame, 21-23...first to third spacers, 3...
・Model, 4', 7'...Resin mold. (Other names) 1 Figure 10 2 Figure 21 22 3 21 Figure 3 4' 4 Figure 5 b Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 59 Figure 14 (The best part of Uguchi)

Claims (1)

[Claims] In an injection mold made of resin, a mold part that can be assembled into a mold base by arranging a casting frame and placing the resin in close contact with the casting frame in anticipation of shrinkage of the casting resin. An injection mold characterized by: