JPS5839432A - Mold for rim - Google Patents

Abstract

PURPOSE:To obviate the deformation that will occur when a gate molded body between molded items is cut, by permitting a plurality of molded items to remain on one of molds, securing one of cutting blocks attached to said mold, and allowing the other to be movable at a right angle with the direction of the opening of the molds and transversely of a runner gate. CONSTITUTION:A resin liquid is injected into first and second item molding sections 12, 13 and a runner gate 14, and after the resin hardens, when the top force 11 is lifted, the molded item 15, 16 remain on the top force 11 due to the presence of undercut sections 15a, 16a. At this time, since the cutting block 21 is guided in a direction (transversely) approximately at a right angle with the direction of the movement of the top force by a slant guide 25, its cutting section 21c is slid laterally in contact with the fixed cutting block 20 thereby the gate molded item 17 is cut. When it is required to close the molds, the movable cutting block 21 is guided by a slant guide pin 25 to be returned to the original position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold for RIM of liquid thermosetting polyurethane, etc., in which a plurality of molded products molded at the same time are cut and separated from each other when the mold is opened.

Molding by RIM (reaction injection molding) is a process in which two liquid columns of sap are reacted in a molded part that is partitioned into an upper mold and a lower mold that can be moved closer to each other. This is a method of manufacturing molded products by injecting isocyanate sap into the molding part of a molded product at high speed and under low pressure, and hardening the sap through a high-speed reaction. Is this RIM molding easier and cheaper to manufacture than normal injection molding? /),White! It is widely used for molding bumpers for kIJ11, etc.

Since this RIM uses liquid injection, multiple molded products can be obtained at the same time with one mold, and while it has the advantage of high manufacturing efficiency, it also has the advantage of having a runner gate that connects the molded parts of each molded product. Therefore, when removing the molded product from the mold after opening the mold, it is necessary to separate the multiple molded products molded at the same time by cutting the runner gate portion.

Therefore, a technique has been developed in which the runner gate portion is cut when the mold is opened by separating and moving the mold. This is illustrated, for example, as shown in Figure 1, and RI
The mold for M has a lower mold 1 and an upper mold 2, and two molded products 3 and 4 are molded in two molded product molding parts formed by both the upper and lower molds 1.2. and these 2
A runner gate is formed to connect the two molded parts, and a rod-shaped gate molded body 5 is formed within this runner gate.

In order to cut this gate molded body 5, two cutting plates 6.
7 are attached to the mold so that they are in contact with each other.

Both cuts 6 and 7 have through holes having the same shape as the runner gate, and one cutting plate 6 is fixed to the lower die and the other cutting plate 7 is fixed to the upper die. In this technique of cutting the gate molded body 5 by utilizing the movement of the upper mold of the mold opening sowing, one of the molded products 3 is moved from the lower mold as shown in FIG. 1(B). First, the mold must be of a type in which the other molded product 4 remains in the upper mold 2.

For this reason, the respective molded products 3 and 4 must have mutually different shapes.

Therefore, as shown in FIG. 2, if the molded products 3 and 4 have substantially the same shape and both of the molded products 3 and 4 are left in the upper mold 2, the cutting plate 6 is placed in the lower mold. 1
When the cutting plate 7 is fixed to the upper mold 2', when the mold is opened, the runner gate 5 on the molded product 3 side is pulled by the cutting plate 6, and especially when the runner gate 5 is attached, an excessive force is applied to the root 5a. There is a drawback that the molded product 3 is deformed by the action.

In view of these problems in the prior art, the present invention allows a plurality of molded products to remain in only one of the molds, and when the molds are opened, two cutting tools are attached to the mold in which the molded products remain. The purpose of the present invention is to solve the problems of the prior art described above by fixing one of the blocks and making the other movable in a direction substantially perpendicular to the mold opening direction and across the runner gate. .

Embodiments of the present invention will be described below with reference to FIGS. 3 to 6.

As shown in FIG. 3, the RIM mold of the present invention has a lower mold 10 and an upper mold 11, and a first molded product forming section 12 and a second molded product forming section 13 are provided between these two molds. A runner gate 14 is provided between these molded product forming parts 12 and 13 to connect them. Then, the first molded product forming section 1
A first molded product 15 is formed at 2, a second molded product 16 is formed at the second molded product forming portion 13, and a gate molded body 17'L is formed at runner gate 4. These two molded products 15
．． 16 has almost the same shape as 4, and when the mold is opened, sap is injected into the first and second molded parts 12.
1, the molded products 15 and 16 remain on the upper mold 11 and adhere thereto because of the undercut portion 15a + 16'a. In addition, in consideration of workability when removing the molded product 15.16 from the mold, the molded product forming part may be configured such that the molded product 15.16 remains in the lower mold 1o. . Recesses 18.19 are formed correspondingly in the one mold and the upper mold at the intermediate position of the runner gate 14, and in these recesses 18.19, a fixed cutting block 20 fixed to the upper mold 11 is inserted. A movable cutting block 21 is housed adjacent to the fixed cutting block 20 and movable in the lateral direction, that is, in the direction substantially perpendicular to the mold opening direction and in the direction crossing the runner gate 14.

The fixed cutting block 20 is fixed to the upper mold 11' by bolts 22 as shown in FIG. As shown in the figure, the wide support part 2. , J, a, and a through hole 21 formed protruding from this support portion 21a and having the same shape as the cross section of the inner gate 14.
It consists of a cutting part 21c having a cut part 2]c.
is in close contact with the fixed cutting block 20. The support part 2
] 7 langes f, f are formed on both sides of the upper end of a, and these 7 langes f are fixed to the upper die 11 by bolts 23.
It is secured by a letter-shaped support 24 so as to be slidable in the apricot direction, that is, in the direction substantially perpendicular to the mold opening direction, and in the □ direction that crosses the runner gate.

2], the support part 2
As shown in FIG. 4, an inclined guide hole 21d is formed in the inclined guide hole 21d, which is inclined at a defined angle with respect to the running direction of the runner gate 14, as shown in FIG. A guide pin 25 is inserted.The toe of this inclined guide lower pin 25 protrudes 7 above the movable cutting block 21, so a space 19a is formed in the recess 19 to accommodate this. A space 19b is formed in the recess 19 so that the movable cutting block 2 can move in the same plane as the running direction of the runner game 14 and in a direction substantially perpendicular to the gear.

When the mold is closed, the runner gate 14 and the through holes 20a and 21b of each cutting block are aligned, but when the mold is opened, the movable cutting tool 21 moves in the direction of movement of the upper mold, as shown in Figure 7. Since the cut portion 21c is guided by the inclined guide 25 in a direction substantially perpendicular to (lateral direction), the cut portion 21c is
It slides laterally while contacting the fixed cutting block 20.

Therefore, the gate molded body 17 is cut.

When the mold is closed, the movable cutting block 21 is again guided by the inclined guide pin 25 and returns to its original position.

In this way, both cutting blocks are attached to the upper mold, one of which is movable in a direction substantially perpendicular to the mold opening direction and across the runner gate 14, so that it automatically moves when the mold is opened. Then, with a simple configuration, the gate molded body can be cut without applying tensile deformation to both molded products.

Also, since the movable cutting block moves laterally, the block does not particularly protrude below the upper mold when the mold is opened, so it does not interfere with the work.

In addition to the combination of the inclined guide pin 25 and the inclined guide hole 21d, the movement conversion for converting the movement of the upper mold 11 into the horizontal movement of the movable cutting block 21 includes:
An elastic body is provided between the recess 19 and the movable cutting block 21,
Thereby, the movable cutting block 21 can be biased in the lateral direction and moved in the lateral direction when the mold is opened. Although the two molds are exemplified as those that open vertically, they may also open left and right.As explained above, according to the present invention, there are two molds that can be opened close to each other. The molds are combined to form at least a plurality of molded product molding sections and a runner gate that connects them, and the plurality of molded products formed in the molded product molding section are formed only in one of the molds when the mold is opened. Two cutting blocks, each having a through hole in a shape corresponding to the cross section of the runner gate, are fixed to the mold on the side where the molded product remains when the mold is opened. the other runner in a direction substantially perpendicular to the mold opening direction;
- A motion converting mechanism is attached to the mold so as to be movable in the direction transverse to the gate, and converts the movement of at least one mold during opening of the mold into the movement of the other cutting block R1 in the transverse direction; Even if multiple molded products adhere to only one of the upper or lower molds and are separated when the mold is opened, the molded products will undergo tensile deformation due to the cutting of the runner gate between the two molded products. This has the effect that a molded product with an accurate shape can be efficiently obtained without any problems. In addition, since the movable cutting block moves laterally, it does not protrude between the two molds when the mold is opened, thereby preventing it from interfering with the mold-releasing operation.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional RIM mold, and Figure 2 shows a case where the conventional technology shown in Figure 1 is applied when all molded products are attached to one mold when the mold is opened. 3 is a vertical sectional view of the RIM mold of the present invention, and FIG. 4 is an enlarged sectional view corresponding to the Ij-■ line in FIG. 3, showing the main parts of the RIM mold of the present invention. , FIG. 5 is a sectional view taken along the line V-V in FIG. 4, FIG. 6 is a view taken in the direction of arrow A in FIG. 5, and FIG. 7 is an explanatory diagram of the state when the mold is opened. DESCRIPTION OF SYMBOLS 10... Lower die, 11... Upper die, 18.19... Recess, 20... Fixed cutting block, 21... Movable cutting block, 20a, 21a... Through hole. 6 5 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] Two molds that can approach and separate from each other are combined to form a molded product molding section of the rod and a runner gate that connects these molded product molding sections, and a plurality of molded products to be molded in the molded product molding section are molded. A molded product molding part is formed so that it remains in only one of the molds when opening, and two cutting blocks each having a through hole in a shape corresponding to the cross section of the runner gate are molded when opening No. 1. One side of the product is fixed on the 6th side of the runner gate, and the other side is attached so that it can be moved in a direction substantially perpendicular to the mold opening direction and across the runner gate, and when the mold is opened. A mold for RIM, characterized in that an interlocking conversion mechanism is attached to the mold for converting movement of at least one mold into movement of the other cutting block in the transverse direction.