JPH07205268A - Blow molding machine for resin molds with undercut parts for connection - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a blow molding machine capable of easily and efficiently molding a resin mold having a tack-off portion and an undercut portion for connection in a short time. [Structure] A female die 8A having a smooth surface, and a male die 8B having a plurality of protrusions 10A and a tack-off core 10 which reciprocates in the die advancing / retracting direction inside are provided. Then, of the protrusions 10A of the tack-off core 10, inside the protrusions 10A at the edge portions, an undercut portion for connection is formed in the molded product in a direction orthogonal to the mold advancing / retracting direction, and can be moved forward and backward. The movable core 20 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding machine for a resin mold for placing concrete, which has a tack-off part, and particularly has a connecting undercut part.

[0002]

2. Description of the Related Art Conventionally, since a concrete casting formwork is inexpensive, a work-formed form of wood has been used, but the surface is scratched by using it once or twice or at most three or four times. The frame type (panel) with is almost disposable,
It was disposed of by incineration. Such a usage example is a big problem in terms of resource protection and environmental problems in the present day when the depletion of wood resources is just around the corner. On the other hand, from such a viewpoint of protecting wood resources, a resin mold produced by a resin molding machine such as an injection molding machine has begun to be used as an alternative, is lightweight and easy to handle, and is repeatedly used 4 to 5 times. It also had the advantage of being able to withstand. In addition to the injection molding machine, the above-mentioned resin molding machine includes a blow molding machine which has a much lower initial cost than the injection molding machine, and has a low running cost at a low pressure and which can mold a resin molded product. In blow molding, which produces a hollow resin product from a parison extruded or extruded in a cylindrical shape from a die head, the parison is injected or extruded from the die head, and the parison formed into a bag by the parison pinch is pre-blown and slightly inflated. , Put it in the open mold, close the mold, and after removing the gas in the cavity formed by the mold and the parison, air is discharged through the vacuum pump device from the small air vent hole communicating with the mold surface. After suction, high-pressure air is blown into the parison to form the parison into a predetermined shape based on the cavity, and then cooled in a mold to complete the molding. In this way, the molded resin product is taken out by opening the mold. FIG. 9 shows a conventional blow molding machine. FIG. 9 shows a so-called side-feed type blow molding machine 1 in which molten resin is supplied from one side of the die head 2, and the high-temperature molten resin pressed by the extruder 4 is the resin supply port 2a. And passes through an annular passage provided between the die head 2 and the mandrel 3 and is discharged from the annular space passage 7 at the lowermost end to form a parison P. Then, the core 3a is connected to the Parison rod 6a penetrating the mandrel 3, and is slightly moved up and down by the operation of the Parison cylinder 6,
The gap of the annular space passage 7 can be adjusted to control the thickness of the parison P.

[0003]

However, when the resin formwork is used for placing concrete, it is necessary to arrange and connect a large number of formworks while maintaining the same plane, and in this case, they are adjacent to each other. It is very troublesome to match the through holes drilled in the same form to each other and tighten the nuts through the through bolts, and many workers are required to connect the form members while maintaining the same plane. Had to work hard. An object of the present invention is to provide a blow molding machine capable of efficiently and inexpensively molding a resin mold having a coupling undercut portion capable of performing the above-described coupling work in a short time and with high precision. Is what you are trying to do.

[0004]

In order to solve the above problems, the present invention provides a blow molding machine for molding a resin mold having an undercut portion for connection. Includes a female die having a smooth flat surface and a male die having a plurality of protrusions and internally having a tack-off core that reciprocates in the die advancing / retreating direction. Of the protrusions of the off-core, the movable core that is movable forward and backward and the movable core that forms an undercut portion for connection in the molded product in the direction orthogonal to the mold reciprocating direction inside the protrusion at the edge end It is configured to include power means.

[0005]

In the blow molding machine of the present invention, the parison is clamped between a female mold having a smooth surface and a male mold having a built-in tack-off core to clamp the tack-off core. While advancing and adhering the uneven panel back surface to the smooth panel surface, the movable core built in the protruding part at the edge of the tack-off core is advanced to move the tack
An undercut portion for connection is formed on the inclined wall surface of the off portion.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 8 relate to an embodiment of the present invention,
1 is an overall vertical cross-sectional view of the blow molding machine, FIG. 2 is an enlarged vertical cross-sectional view of a male mold of the blow molding machine, FIG. 3 is a perspective view of a resin mold, and FIG. 4 is a plan view of the resin mold. 5, FIG. 5 is a side sectional view of the resin form, FIG. 6 is a side sectional view of the resin form connecting portion, FIG. 7 is a plan view of the resin form connecting portion, and FIG. 8 is a perspective view of the movable core.

As shown in FIG. 1, a blow molding machine 1 includes a die head 2, a mandrel 3, an extruder 4 and a Parison cylinder 6 which have the same structure as a conventional structure and forms a parison (particularly a flat parison) P into a pair of left and right dies 8. Droop between. In the blow molding machine 1 of the present invention, the mold 8 is different from the conventional structure, and the male mold includes a female mold 8A having a smooth cavity surface and a tack-off core 10 having a plurality of protrusions 10A. Of the protrusions 10A of the male die 8B, the protrusions 10A at the edge portions such as the uppermost step and the lowermost step are hollow inside, and the through holes 10B are formed above and below, respectively. As shown in FIG. 2, a movable core 20 is provided which can reciprocate in the axial direction by the operation of the air cylinder 20a. A stopper 20b is provided at the lower end of the movable core 20, and contacts the inclined inner wall surface of the tuck-off core 10 to regulate the stroke end of the movable core 20. The function of the movable core 20 is that the undercut portion 36 of the panel-shaped molded product (specifically, a resin frame) 30 shown in FIGS.
To form the parison P. Male mold 8B of blow molding machine 1 for molding panel-shaped molded product 30 of FIG.
Then, a total of eight movable cores 20 are built in the protrusion 10A.

In the blow molding machine 1 having the mold 8 (female mold 8A and male mold 8B) configured as described above, the parison having a circular cross section is obtained by opening the molds 8A and 8B. P (preferably a substantially elliptical flat parison having a major axis in the lateral direction of the mold) is hung down and then stopped, and then a mold clamping cylinder (not shown) mounted outside the left and right molds 8A and 8B is operated. And clamp the mold. In the mold clamping process, the tack-off core 10 which was retracted in the direction of the male mold 8B after the mold clamping.
Is gently advanced, and is advanced and stopped until the panel back surface 34 comes into contact with the back side surface of the panel front surface 32. After that, the movable core 20 is moved forward to form a recess (undercut portion) 36 as shown in FIG. 5 on the slope of the tack-off portion of the panel back surface 34. In this way, after molding the parison P inside the mold into the shape as shown in FIG. 3, the mold is clamped and held for a certain cooling time, and then the movable core 20 is retracted.
The mold is opened and the molded product is taken out.

FIGS. 6 to 7 show a case where resin molds 30 having undercut portions molded as described above are connected to each other, and the adjacent resin molds 30 and 30 have the same panel surface. After arranging so that they are connected to each other, the connecting tool 40 is used to connect them. The connecting tool 40 is of a one-touch lever type, and is a direction in which the connecting ring 40b is passed through the hook 40a to tightly connect the lever 40c (clockwise direction in FIG. 6).
Turn to.

As the undercut portion 36 of the resin mold 30, a circular or rectangular shape or one having a curved tip is used, and accordingly the movable core 20 may have a shape as shown in FIG. it can.

As described above, in the blow molding machine 1 of the present invention, the resin mold 30 having the undercut portion having an arbitrary shape can be easily and easily manufactured. It is possible to omit the drilling for connecting the.

[0012]

According to the blow molding machine of the present invention, a resin mold having a tack-off portion and having a large structural strength and which can be easily connected can be manufactured efficiently in a short time and at a low cost. In addition, the resin mold with the molded undercut portion for connection does not require post-processing (hole processing) for connection, there is no displacement of the form at the time of connection, and connection work (connection and release) is simple with one touch. Can be carried out.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view of a blow molding machine according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of a male mold of a blow molding machine according to an embodiment of the present invention.

FIG. 3 is a perspective view of a panel-shaped molded product (resin mold) according to an embodiment of the present invention.

FIG. 4 is a plan view of a panel-shaped molded product (resin mold) according to an embodiment of the present invention.

FIG. 5 is a side sectional view of a panel-shaped molded product (resin mold) according to an embodiment of the present invention.

FIG. 6 is a side sectional view of a connecting portion of a panel-shaped molded product (resin mold) according to the embodiment of the present invention.

FIG. 7 is a plan view of a connecting portion of a panel-shaped molded product (resin mold) according to the embodiment of the present invention.

FIG. 8 is a perspective view of a movable core according to an embodiment of the present invention.

FIG. 9 is an overall vertical sectional view of a conventional blow molding machine.

[Explanation of symbols]

 1 Blow Molding Machine 2 Die Head 3 Mandrel 4 Extruder 6 Paricon Cylinder 7 Annular Space Passage 8 Mold 8A Female Mold 8B Male Mold 9 Platen 10 Tuck-off Core 10A Projection 10B Through Hole 10a Hydraulic Cylinder 20 Movable core 20a Air cylinder 20b Stopper 30 Panel-shaped molded product (resin formwork) 32 Panel front surface 34 Panel back surface 36 Undercut portion 40 Connecting tool 40a Hook 40b Connecting ring 40c Lever P Parison

Claims (1)

[Claims] 1. A blow molding machine for molding a resin mold having a connecting undercut portion, the blow molding machine comprising a female mold having a smooth flat surface and a metal mold having a plurality of protrusions. A male mold having a tack-off core that reciprocates in the mold advancing and retracting direction inside, and the mold advancing and retracting inside the protrusion at the edge of the protrusions of the tack-off core. A blow molding machine for a resin mold having a movable core that is movable forward and backward to form an undercut portion for connection in a molded product in a direction orthogonal to the moving direction and an undercut portion for connection provided with power means for the movable core.