JPS6356847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for holding a reinforcing material to be enclosed in a synthetic resin molded body in a cavity of a molding frame.

One of the conventional methods for holding reinforcing material in the cavity during molding is to clamp and fix the reinforcing material at multiple points in the longitudinal direction with a pair of front and back pins. If the filled molten resin is held between pins until it solidifies, the position will be held very reliably, but on the other hand, the pin marks will create a void where the resin cannot wrap around, and the reinforcing material will be exposed in this area. Not only does it look unsightly, but the exposed parts tend to rust and corrode due to moisture. As a countermeasure for this, the pin is removed from the cavity while the molten resin has fluidity, and the internal volume of the cavity is reduced by secondary pressure, and the void where the pin left the exit is filled with the molten resin. A number of techniques have been proposed. This is schematically illustrated in Figures 6A to 6D. Here, 21 is the reinforcing material, 22 is the pin, 23 is the molding frame, 24 is the cavity, 25 is the resin, A is the reinforcing material holding, B is the molten resin injection and filling, C is the pin withdrawal, and D is the internal volume of the cavity. Represents a decrease.

However, in this case, the configuration of the secondary pressurizing mechanism for reducing the cavity internal volume is extremely complicated, leading to a significant increase in capital investment. The relationship between the withdrawal timing and the change in the position of the reinforcement, () the setting of mutual contact conditions between the reinforcement and the pin (pin tip shape, holding method, etc.), () the relationship between the reinforcement material dimensional tolerance and the pin, etc. It was extremely difficult to set the overall conditions, and filling in the blanks where the pins left the exits was in an unfavorable state. In particular, as is clear from Figure 6 (c) and (d), in order to fill the pin exit hole 26, it is necessary to flow all the resin around it, and the flow resistance is quite large, so the above situation is I was invited. In addition, the coating thickness of the resin becomes larger than necessary, leading to an increase in costs.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and drawbacks, it is an object of the present invention to provide a simple and inexpensive structure that allows a reinforcing material to be coated and finished reliably and satisfactorily.

The position holding device for a reinforcing material for inclusion in a resin molded body according to the present invention includes a cylindrical first member that is movable in and out of the cavity and that can press its tip against the reinforcing material when protruding. Forming a recess into which a part of the molten resin to be injected and filled into the cavity flows and stores it, and the resin stored in the recess is removed as the first member moves out.
A pin-shaped second pin to push it out toward the empty space where it exited.
It is characterized by being provided with a member or a compressed fluid flow path.

That is, when the first member presses the reinforcing material in its protruding position in the mold matching state and holds the reinforcing material at a predetermined position in the cavity, then when the molten resin is injected into the cavity, the molten resin is reinforcing. While surrounding the material, a portion thereof also flows into the recess formed in the first member and is stored there. Then, at an appropriate time when the molten resin has fluidity, the first member is moved out and moved, and the second member is moved to protrude or pressure is applied through the flow path, so that the resin stored in the recess is removed. is extruded toward the empty space left by the exit of the first member, and this empty space is filled with extruded resin.

In this case, () the empty space left by the exit is filled without reducing the internal volume of the cavity or with minimizing the reduction;

() The resin that is being prepared to fill the empty space left by the exit site is present in the recess formed in the first member itself, which is the cause of this empty space. The amount of resin flowed to fill the voids is much smaller than in the past.

() For the same reason as () above, the flow resistance of the resin is greatly reduced compared to the conventional method.

Therefore, as a whole, it is possible to ensure and improve the effect of filling the empty spaces with the resin, that is, the effect of coating the reinforcing material with the resin, and the structure for this purpose is sufficiently simple and easy to implement economically. .

In particular, because of the above (), (), and (), it is easy to set the timing for the withdrawal of the first member, and therefore, by setting this timing at a late stage of resin solidification, the position holding effect on the reinforcing material is ensured. can do. In other words, the duration of the position-holding action based on the pressing of the first member can be extended, and the reinforcing member position-holding action by the surrounding resin after the first member leaves is strong because the surrounding resin has a high degree of solidification. Because it will be. Conventionally, it was necessary to set the pin withdrawal at a fairly early timing, and in order to maintain the position with the surrounding resin, the resin coating thickness had to be thicker than necessary, and therefore shrinkage stress was likely to occur. In contrast, the thickness of the resin coating during solidification tends to be uneven due to the need to flow all the resin around the area to fill the void.However, according to the present invention, the thickness of the resin coating can be reduced to reduce costs. It is easy to reduce the thickness of the coating, and it is also easy to make the coating thickness uniform and improve the product value.

The principle of implementation of the present invention will be explained below with reference to the schematic diagrams in FIGS.

1 is a reinforcing material to be embedded in the synthetic resin molded body, 2
indicates the molding frame, 3 indicates its cavity, and 4 indicates the resin.

5 is a cylindrical first part that can move in and out of the cavity 3.
The member presses its tip against the reinforcing material 1 when projected. Reference numeral 6 denotes a recess formed on the pressing tip side of the first member 5, into which a portion 4a of the molten resin 4 to be injected and filled into the cavity 3 flows and is stored. Reference numeral 7 designates a pin-shaped second member for pushing out the stored resin 4a toward the space 8 created when the first member 5 exits. Instead of this second member 7, a recess 6 as shown in FIG.
A compressed fluid flow path 7' may be provided which communicates with the compressed fluid flow path 7'. 9
is a vane, and 10 is a stopper.

The two first members 5 as described above are arranged facing each other on the same or almost the same straight line so as to correspond to both the front and back surfaces of the reinforcing material 1, and the reinforcing material 1 is held between the pair of first members 5, 5. However, one of these (if the product has two sides, the one on the back side)
In place of this, it is also possible to use a conventional or appropriate egress pin or fixed holding block.

In addition, in FIG. 1, the recess 6 is opened at the end surface of the first member 5 in the protruding direction, and the reinforcing material 1 is inserted into this opening.
Although a notch 11 is formed which communicates with the cavity 3 in the pressed position, instead of this, a recess 6 is opened and communicated with the cavity 3 on the circumferential surface of the first member 5 as shown in FIG. Good too.

Further, although a flat bar is illustrated as the reinforcing material 1, this is done in consideration of the fact that the flow resistance of resin, which is one of the conventional drawbacks, is significant in the case of a flat bar. In other words, this device is particularly effective when holding flat bars. however,
A square pipe can be anything such as a round pipe or a round bar. Figure 4 shows the case of a round pipe. An example of the operating mechanism of the first member 5 and the second member 7 is shown in FIG. This is the reciprocating shifter 12 of the first member 5,
Forward shifter 13 of second member 7, return spring 1
It is equipped with 4. 15 is a fixed formwork, 16 is a movable formwork, and 17 is a fixed plate.

This apparatus is particularly effective when injection molding a synthetic resin pallet in which reinforcing materials 1 are assembled in a vertical and horizontal lattice pattern and sealed on both upper and lower deck surfaces thereof.

It would also be effective to heat the fluid passing through the pin-shaped second member 7 or the flow path 7' to maintain the fluidity of the resin flowing into the recess 6 for a longer period of time.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the position holding device for a reinforcing material encapsulated in a resin molded body according to the present invention. A schematic structural diagram of an application example, FIG. 5 is a schematic structural diagram showing an example of an exit/exit means, and FIG.
Figures A to D are explanatory diagrams of the schematic structure and sequential operations of the conventional device. DESCRIPTION OF SYMBOLS 1... Reinforcement material, 3... Cavity, 5... Cylindrical first member, 6... Recess, 7... Pin-shaped second member,
7'... Compressed fluid flow path, 11... Notch.

Claims (1)

[Scope of Claims] 1 A device for holding a reinforcing material 1 to be enclosed in a synthetic resin molded body in a cavity 3 of a molding frame, which is movable in and out of the cavity 3 and prevents the reinforcing material 1 from moving in and out of the cavity 3 when protruding. A recess 6 is formed on the pressing tip side of the cylindrical first member 5 whose tip can be pressed against the reinforcing material 1, into which a part of the molten resin to be injected and filled into the cavity 3 flows and is stored. , a pin-shaped second member 7 or a compressed fluid flow path 7' is provided for pushing out the resin stored in the recess 6 toward the empty space where the first member 5 exits as the first member 5 exits. A position holding device for reinforcing material for inclusion in a resin molded body, characterized in that: 2. The reinforcing material for inclusion in a resin molded body according to claim 1, wherein two of the first members 5 are arranged facing each other on the same or almost the same straight line so as to correspond to both the front and back surfaces of the reinforcing material 1. position holding device. 3. A position holding device for a reinforcing material for inclusion in a resin molded body according to claim 1 or 2, wherein the reinforcing material 1 is intended for a flat bar. 4 The recess 6 is opened at the end face of the first member 5 in the protrusion direction, and the opening is a notch 1 communicating with the cavity 3 in a pressed position against the reinforcing member 1.
Claims 1 to 3 having
A position holding device for a reinforcing material for inclusion in a resin molded body according to any one of Items 1 to 9. 5. The reinforcing material 1 according to any one of claims 1 to 4, wherein the reinforcing material 1 is intended for at least a part of a group of reinforcing materials in a vertical and horizontal lattice shape enclosed in a synthetic resin pallet. Position holding device for reinforcing material encapsulated in resin molded body.