JPH0351572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an outer mold device for molding a socket used for forming a joint socket at the end of a resin pipe.

In regular length resin pipes that are connected to each other and used in a coupled state, a joint socket is usually molded at one end of the pipe, and the general shape of the pipe end is , as shown in Figure 1,
The end of the pipe P forms a large-diameter portion A, and a socket portion B is formed near the tip of the large-diameter portion A with a bulging shape to provide a space for receiving a sealing member. .

However, in the conventional standard molding method,
First, after heating the end of the pipe material (hereinafter referred to as the workpiece), the workpiece is inserted into the inner mold T as shown in the figure.
As shown in the figure, floating cavities C are formed at the bent corners of the bulging cross-section, and therefore, accurate molding dimensions cannot be obtained as is, so as a subsequent step,
Squeezing press using an outer die is carried out in hot condition.
As a result, the cavity C created by the above-mentioned floating is crushed.

By the way, the structure of the outer mold generally used in the past is such that three or more split molds are moved back and forth in the radial direction to perform the pressing, but the structure and operation are complicated. This was unavoidable, and problems such as a frequent occurrence of defective products occurred due to the timing difference between the forward and backward movement of each split mold.

In view of these problems with the conventional method, a method using half-split molds has been considered. Specifically, a pair of half-split molds are placed facing each other on the diameter line approximately at the center of the socket B. This is a method in which the workpiece is moved close to each other so as to be sandwiched between the workpieces.

By the way, this method using half molds has the advantage that the configuration of the press mechanism is extremely simplified compared to the conventional method of pressing from the radial direction using three or more split molds. On the other hand, because the workpiece extrusion direction at the end of the half-split mold is close to the tangential direction of the workpiece, the pipe flesh may get caught between the molds and create large burrs.
In addition, there was a drawback that it was difficult to obtain good processing quality, such as pressing the pipe meat diagonally and reducing the roundness after molding.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a socket molding outer mold device that can obtain good processing quality using a pair of half-split molds. It is about providing.

In order to achieve the above object, the outer mold device for socket molding of the present invention has the following features: In the outer mold device used for processing for molding the joint socket B at the end of the resin pipe P, the outer mold device is arranged in opposite directions to each other. A pair of partial molds 1A and 1B each having a substantially half-cylindrical shape and whose inner circumferential mold surface becomes approximately cylindrical when brought close to each other, and the pair of partial molds 1A and 1B. an extrusion protrusion 8 protruding from one side of the opposing split end surfaces and a sliding protrusion 9 protruding from the other side; A pressing slope 8 is formed on a wall surface facing the central axis of the substantially cylindrical mold surface to be formed in a substantially eight-shape shape so as to open in the direction of the substantially cylindrical mold surface.
a and a sliding slope 9a, and a separated substantially cylindrical mold surface of the pair of partial molds 1A and 1B that is slidably in contact with the sliding slope 9a of the sliding overhang 9 and is slidably provided on the sliding slope 9a. A substantially wedge-shaped movable mold 5 is formed with a continuous mold surface.
In conjunction with the close movement between the pair of partial molds 1A and 1B, the movable mold 5 is pressed by the pressing slope 8a and slides on the sliding slope 9a, and moves in the centripetal direction. It is characterized in that the mold surfaces of the pair of partial molds 1A, 1B and the movable mold 5 are continuous in a substantially cylindrical shape.

Hereinafter, the present invention will be explained based on an illustrated embodiment, but the mold surface shape in the drawings referred to below is the third embodiment.
Like the model socket part B shown in the figure, the shape corresponds to a socket part having a simple trapezoidal bulge shape.

The outer mold device of the embodiment is shown in Fig. 4 a, b to Fig. 7.
As shown in the figure, a pair of left and right half-split molds 1A,
1B, and both partial molds 1A, 1B are formed in mutually symmetrical shapes, and each partial mold 1A,
1B is fixed and held by symmetrical left and right brackets 2A and 2B, and each bracket 2
A, 2b are vertically supported at the tips of the piston arms 4 of the left and right actuating cylinders 3 installed in immovable parts, and hereinafter, the left half-split mold 1A
The formation mode will be specifically described.

As can be easily seen from FIG. 4b, the front shape of the partial mold 1A consisting of a half ring is a semicircular shape with the diameter side cut off, except for the protruding portion along the diameter line. In other words, half of the arc width of the movable type 5, which will be described later, is cut off.
Incidentally, a suitably shaped hollow space 6 is formed in the body to reduce the weight.

Next, a mold groove 7 having a desired cross-sectional shape is indented into the inner peripheral surface of the partial mold 1A that forms the press mold surface, and the lower surface is formed into an extrusion slope 8a on the split end surface above the mold surface. A pressed overhang 8 is provided protrudingly,
The width end of the tip of the pressing bulge 8 is slightly cut off in order to provide clearance for contact with other members.

On the other hand, a sliding bulge 9 whose upper surface is formed into a sliding slope 9a is formed on the split end surface below the mold surface, and a spring groove in which the lower half of the return spring 10 is inserted into the sliding slope 9a. 9b is formed, and the back half of the insertion spring 10 enters into a blind hole in the mold, which is bored on an extension line of the groove 9b.

That is, the pressing slope 8b of the pressing projection 8 and the sliding slope 9a of the sliding projection 9 are formed by a pair of partial molds 1A,
It is formed into a substantially eight-shaped shape so as to open toward the center axis of the substantially cylindrical shape formed by the circumferential surface of 1B.

Further, a retaining plate 11 made of a square plate is fastened to the lower surface of the sliding overhang 9 with two screws, and a pair of guide frames 13 are provided on both sides of the sliding overhang 9. It is fastened with real screws 14, and a collar-shaped rail 13a protrudes from the upper edge of each frame 13.

By the way, the movable mold 5 formed separately has an arc-shaped upper surface forming a mold surface, and a mold groove 5a is recessed in the mold surface, and the lower half thereof is pressed. It has a wedge shape formed by the surface 5b and the sliding surface 5c, and a narrow contact surface 5d is formed at the bottom thereof, and sliding grooves 5e are formed at the bottoms of both sides of the sliding surface 5c. At the same time, a spring groove 5f is bored in the center of the sliding surface 5c, into which the upper half of the return spring 10 enters, and a spring groove 5f, into which the upper half of the return spring 10 enters, is formed in the middle of the groove 5f. A matching receiving pin 15 is planted downward.

However, the moving type 5 of the lever has its sliding surface 5c
After sliding onto the sliding slope 9a, the sliding groove 5
e is guided by the rail 13a of the guide frame 13, which allows it to freely move up and down on the sliding slope 9a, but at the lower end position of the descent, the abutting surface 5d hits the retaining plate 11 to prevent it from coming off. has been carried out, and
The movable mold 5 in a free state is always pressed down by the return spring 10 via the receiving pin 15.
is held at the lower end of descent.

Next, an explanation will be given of the operation and device operation when the socket B is drawn by the outer mold device configured as described above.

First, by operating the actuating cylinders 3 on both sides and retracting the piston arm 4, the fourth
As shown in Figure a, the distance between the two partial molds 1A and 1B is widened, and the socket part B of the workpiece P held in the inner mold T is positioned in the center between the two partial molds 1A and 1B. .

Next, when the actuating cylinder 3 is operated in the protruding direction of the arm 4 to move the partial molds 1A and 1B close to each other, in the course of the close movement, the pressing slope 8a of each pressing bulge 8 is pressed against the other side. hits the pressing surface 5b of the movable mold 5, and thereafter each movable mold 5
Due to the wedge action caused by the pressure between the pressing slope 8a and the sliding slope 9a, the slider 10 moves in a substantially centripetal direction with a strong force against the elasticity of the return spring 10.

Therefore, in the state shown in FIG. 4b where the mold surfaces of both partial molds 1A and 1B are in contact with the outer periphery of the work P, the mold surfaces of each movable mold 5 are also in contact with the outer periphery of the work P at the same time, and at this point, the movable The die 5 presses the workpiece P in the centripetal direction.

Next, after squeezing and pressing the work P for the required time with the required pressure, if the cylinder 3 is operated in the retracting direction, the partial molds 1A, 1B and both movable molds 5 will be easily separated from the work P, and thereby the press After the operation is completed, the cavity C of the socket B is collapsed.

In such a press operation, each part of the mold surface uniformly presses the workpiece in the centripetal direction or in a direction close to the centripetal direction, so that the pipe in a softened state can be seen in the cracks between the partial molds 1A, 1B and the movable mold 5. There is no possibility that the meat will be chewed or the pipe meat near the cracks will become uneven.

Here, the movable mold 5 of the above embodiment has a so-called base shape with both sides of the upper half parallel to each other as shown in FIG. 7, but as shown in FIG. Both sides of the portion may be tapered in an eight-shape, and the facing surfaces of the partial molds 1A and 1B may be in an inverted eight-shape. By adopting such a shape, it is possible to more effectively prevent the flesh from being eaten by the molding outer mold on the molding outer peripheral surface of the pipe, and the molding line can also be formed in a straight line.

Furthermore, as shown in FIG. 9, the movable die 5 may be formed in a triangular shape as a whole, and the spring groove 5f in the embodiments shown in FIGS. 7 and 8 may be omitted. In the embodiment shown in FIG. 9, the receiving pin 15 projects into the spring groove 9b of the opposing partial molds.

In addition, in the configuration of the embodiment, a pair of movable molds may be assembled to either one of the partial molds, or a cutout may be formed only in one of the split parts to form a single A sector type may be interposed.

Furthermore, the pipe end to be processed is not limited to the socket for a joint, but can be widely applied to any pipe end having a similar bulge. In addition, it can be applied not only to circular pipes but also to various oddly shaped pipes such as oval and egg shapes.

As described above, according to the outer mold device for socket molding according to the present invention, the movable mold 5 is connected to the pair of partial molds 1A,
Since the structure is such that the socket part B of the pipe P is drawn and pressed in conjunction with the proximity operation of the pipe P, forming can be performed with a simple operation without the need for a particularly complicated mechanism, and the pipe receiving part B can be pressed by drawing. It becomes possible to accurately process and mold the shape and dimensional accuracy of the product after molding the mouth part, which has the effect of improving the processing quality during socket molding.

[Brief explanation of drawings]

Figure 1 is a sectional view of the end of the resin pipe held in the inner mold, Figure 2 is a sectional view of the cavity created in the socket, and Figure 3 is the end of the pipe whose shape is modeled. Figure 4a is a front view of an outer mold device for socket molding showing an embodiment of the present invention, Figure 4b is an operation diagram of Figure 4a, and Figure 5 is Figure 4a. 6 is an enlarged separated view of the portion shown in FIG. 5, FIG. 7 is a side sectional view taken along the - line in FIG. 6, and FIGS. 8 and 9. 3A and 3B are cross-sectional views of movable types according to other embodiments, respectively. P...Resin pipe (work), B...Socket part,
1A, 1B... Partial mold, 5... Moving type, 8... Pressing overhang, 8a... Pressing slope, 9... Sliding overhang, 9
a...Slip slope.

Claims (1)

[Scope of Claims] 1. An outer mold device used for processing for molding a joint socket B at the end of a resin pipe P, which is capable of approaching and separating from each other in opposite directions, and when brought close to each other. A pair of half-cylindrical partial molds 1A, 1B whose inner circumferential mold surfaces are approximately cylindrical, and a pressing bulge protruding from one of the opposing split end surfaces of the pair of partial molds 1A, 1B. 8 and a sliding protrusion 9 protruding to the other side; and the pressing protrusion 8 and the sliding protrusion 9 are arranged toward the central axis of the substantially cylindrical mold surface formed by the pair of partial molds 1A and 1B. A pressing slope 8 is formed on the wall surface in a substantially eight-shape so as to open in the direction of the substantially cylindrical mold surface.
a and a sliding slope 9a, and a separated substantially cylindrical mold surface of the pair of partial molds 1A and 1B that is slidably in contact with the sliding slope 9a of the sliding overhang 9 and is slidably provided on the sliding slope 9a. A substantially wedge-shaped movable mold 5 is formed with a mold surface that continues the
In conjunction with the close movement between the pair of partial molds 1A and 1B, the movable mold 5 is pressed by the pressing slope 8a and slides on the sliding slope 9a, and moves in the centripetal direction. An outer mold device for socket molding characterized in that the mold surfaces of a pair of partial molds 1A, 1B and a movable mold 5 are continuous in a substantially cylindrical shape.