JPH0238069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mold for molding a pipe joint, and more particularly to a mold for molding a pipe joint having a curved portion.

[Conventional technology and its problems]

Generally, when forming pipe fittings such as elbows, the small diameter side curved surface of the intermediate curved part (this is called the undercut surface) becomes an undercut, so the middle part (core) corresponding to the hollow part of the elbow will not be joined as is. It cannot be pulled out in the direction of the socket.

Therefore, various proposals have been made to easily pull out the medium size and increase productivity when molding a pipe joint having an undercut surface. For example, as a so-called parent-child middle mold, the middle mold for elbow molding is divided into two parts: a middle mold for the undercut surface, and a main middle mold for molding the large-diameter side curved surface of the middle curved part of the elbow, and when the movable outer mold opens, As a result, only the parent middle die moves appropriately toward the elbow joint and stops, but since the moving outer die operates to open, the lower middle die for the undercut surface swings away from the undercut surface, and the elbow separates. A proposal has been made (Utility Model Publication No. 52-42953).

In addition, as a parent and child medium type, in the elbow medium type,
It is divided into two parts so that it can be inserted from the elbow joint in two directions with the undercut surface in the center, and
The divided medium mold is divided into two parts: a main mold with a dovetail groove carved on the sloped surface thereof, a secondary medium mold for undercut surface that engages with the dovetail groove and has an extension surface of the sloped surface, and the secondary medium mold. It is further divided into 3 parts with the auxiliary middle die pushing up, and if only the parent middle die moves appropriately toward the elbow joint, the auxiliary middle die receives the child middle die, so the child middle die will move under the dovetail groove. A proposal has been made to move away from the cut surface in the direction of the elbow center position so that the elbow can be detached (Jikkosho).
57-36410).

However, in the former proposal, the core mold for the undercut surface is stationary at the beginning of the regression movement of the parent core, which requires a corresponding amount of molding time.Moreover, during the reciprocating movement of the entire core, the movement of the core mold is not complete. Since swinging or rotational motion is applied to the parts, if the mold is opened and closed for a long period of time, it is likely that the mold will shake or snap. In addition, in the latter proposal, as a means of separating the child medium die for the undercut surface from the undercut surface, the child medium die is engaged with a dovetail groove on the sloped surface of the parent medium die, so that as soon as the parent medium die begins to move backward, the child medium die is moved away from the undercut surface. begins to separate from the undercut surface, but since the engagement between the parent mold and the secondary mold is done through the dovetail groove, the distance from which the secondary mold can separate from the undercut surface is limited, and therefore, it is possible to The range of application of the joint is also limited, and in addition, the tip of the sloped surface of the parent mold and the tip of the sloped surface of the child center mold, especially in the case of a mass production mold, will become difficult to match if such mass production continues, and the mold The phenomenon of blurring and galling is likely to occur. We also need auxiliary medium-sized units.

[Means for solving problems]

Therefore, the present invention was created in order to solve the problems of the prior art, and uses a medium-sized piece having a mold surface shape corresponding to the inner surface shape of the pipe joint, with the undercut surface in the center. In the mold for forming a pipe joint, the divided medium mold is further divided into a child medium mold for the undercut surface and a parent medium mold constituting the remainder thereof, wherein the parent medium mold is inserted into the pipe joint from the bottom. A rod for advancing and retracting the child middle mold is provided so as to be inclined outward with respect to the direction of regression toward the joining part, and the rod is slidably inserted and supported through the parent middle mold and its base, so that the child middle mold is moved by the regression of the parent middle mold. is separated from the undercut surface, and a one-way locking device for temporarily stopping the rod from regressing is provided at the rear of the rod, and the locking device is released by the regression of the parent middle mold, allowing the child middle mold to retreat. An object of the present invention is to provide a mold for forming a pipe joint.

[Effect]

As a pipe joint, in order to remove the injection-molded cheese from the mold as shown in FIG. 2, the movable outer mold is opened and the middle mold is pulled out toward the joint of the cheese. During this operation, the main mold starts to be retracted by the hydraulic cylinder, but the secondary mold is stopped by a one-way locking device for stopping retraction, so
A force in the retraction direction of the parent middle mold acts on the outwardly inclined rod, causing the rod to slide toward the center of the cheese and separating the child middle mold from the undercut surface. Further, when the main mold is retracted, the locking device is released, the secondary mold and the rod are retracted together with the main mold by the hydraulic cylinder, and the cheese can be removed from the mold.

〔Example〕

The details of the configuration of the present invention will be explained using examples.

Figure 1 is a perspective view of the main parts of this embodiment, and Figure 2 is a perspective view of the main parts of this embodiment.
A partially cutaway plan view as seen from arrow A in the figure, Figure 3 is B in Figure 1.
An arbitrary cross-sectional view based on ~B is shown. The present embodiment relates to an apparatus for molding a sewer pipe cheese 1 with a nominal diameter of 250 mm, for example, by injection molding, and pulling out a mold, especially a medium size P, P'... The cheese 1 has three joints 2, 2... Therefore, there are two undercut surfaces 3. The following description will concern only one of these joints.

The medium size P is divided into two parts at the center of the undercut surface 3, and the parting surface 4 thereof is substantially aligned with the normal line of the undercut surface 3. This two-divided medium die P is further divided into two by a parent medium die 5 and a child medium die 6 for the undercut surface 3, and the parent medium die 5 and child medium die 6 constitute the parting surface 4.
The child middle mold 6 has a pointed shape, one surface of which constitutes a parting surface 4, and the other surface slidably in close contact with the parent middle mold 5 at an outward inclination angle α. A rod 7 for advancing and retracting is protruded from the rear of the secondary middle mold 6, and the rod 7
is slidably inserted into and supported by the main mold 5 and its base 8, and the rear end of the rod 7 is inserted into the horizontal frame 9 by a dovetail groove 11 (FIG. 3) within the elongated hole 10 of the horizontal frame 9.
, so that the rod 7 is stopped in the axial direction of the rod, but is free to slide in a direction substantially perpendicular thereto. The horizontal frame 9
is supported by the mold body 12 so as to be slidable in the opening/closing direction of the middle mold P.

The main mold 5 is composed of a portion 13 for molding the joint 2 of the cheese 1 and a base 8. A piston rod 15 is locked to the rear surface 14 of the base 8, and is reciprocated by a hydraulic cylinder 16. It's summery. Two ski-shaped sliding feet 17 are protruded from the lower part of the rear surface 14 of the base 8, and when the parent middle mold 5 retracts, the sliding feet 17 lock into a lock for temporarily stopping the regression of the child middle mold 6, which will be described later. It is designed to release device Q.

The locking device Q is a so-called one-way locking device, which locks the rod 7 only when it retracts, and allows the rod 7 to move freely when it advances. That is, it is formed into two stages, with a cam 18 provided on one stage and a hook 19 provided on the other stage. The cam 1
Reference numeral 8 denotes a portion 18 that is in constant contact with the sliding foot 17.
a and a raised portion 18b, the sliding foot 17
When the lock device Q rides on the raised portion 18b, the locking device Q rotates downward about the pivot shaft 21 supported by the mold body 12 against the spring 20 supported by the mold body 12. As a result, the stopper rod 22 protruding below the horizontal frame 9 is disengaged from the hook 19.

23, 23 is a child medium size of another medium size P′, and the medium size
Since P' has two undercut surfaces, it has two intermediate molds, but their operation is the same as that of the intermediate mold P described above. Reference numeral 24 indicates a movable outer mold, and 25 indicates a fixed outer mold.

Since this embodiment has the configuration described above, it performs the following operations. That is, in order to remove the injection-molded cheese 1 from the mold as shown in FIG. 2, the middle mold P is moved toward the joint of the cheese 1 while the outer mold 24 is opened. During such movement, since the piston rod 15 is locked to the base 8, the master middle mold 5 starts to retreat by the hydraulic cylinder 16, but the child middle mold 6 moves through the rod 7, the dovetail groove 11, the horizontal frame 9, and the stopper rod 22. The rod 7 is locked to the mold body 12 by the hook 19, and therefore the force X in the retraction direction of the master mold 5 is applied to the rod 7 which is inclined outward.
The rod 7 is slid toward the center of the cheese 1 while being guided by the dovetail groove 11, and the middle mold 6 is separated from the undercut surface 3. When the master mold 5 further retreats, the sliding foot 17 rides on the protrusion 18b of the cam 18, and the locking device Q is rotated downward about the pivot 21. As a result, the stopper rod 22 comes off from the hook 19, the rear surface 14 of the base 8 comes into contact with the horizontal frame 9, and the horizontal frame 9 is retracted together with the base 8, so that the medium size P is completely removed.

On the other hand, in order to advance the medium mold P for injection molding, the hydraulic cylinder 16 presses the rear surface 14 of the base 8 with the piston rod 15 in the opposite manner to the above to close the mold.

Note that a dovetail groove may be further formed on the surface where the parent middle mold 5 and the child middle mold 6 are slidably in close contact with each other outwardly at an inclination angle α. Furthermore, it goes without saying that the number of parent medium molds 5 may not be one.

In summary, since the present invention adopts the structure set forth in the claims, the present invention has the following effects.

〔Effect of the invention〕

The initial regression force of the parent middle mold acts on the rod of the child middle mold, and the child middle mold is slid away from the undercut surface in the direction of the pipe joint center position, so the mold release operation of the child middle mold is simplified, and it can be used for both large and small diameters. It can also be applied to the molding of pipe joints, and there is no process time loss, making it suitable for mass production molds.In addition, since the entire rod receives the regression force of the parent mold, the sliding of the child and middle molds is performed smoothly, making it suitable for mass production. Even when used in a mold, the parent and child molds can move accurately relative to each other, and a one-way lock device is installed at the rear of the rod, so the movement of the child mold, ie, temporary stop and regression, is prevented. It is carried out accurately, and in this respect, it is suitable for mass production molds, and of course, it is possible to suppress the shaking and galling phenomena of the parent and child middle molds as much as possible.

[Brief explanation of drawings]

Figure 1 is a perspective view of the main parts of this embodiment, and Figure 2 is a perspective view of the main parts of this embodiment.
A partially cutaway plan view as seen from arrow A in the figure, Figure 3 is B in Figure 1.
An arbitrary cross-sectional view based on ~B is shown. 3... Undercut surface, 5... Main medium type, 6...
...Middle size, 7...Rod, 8...Base, P...Medium size, Q...Lock device, α...Inclination angle.

Claims (1)

[Scope of Claims] 1. A medium mold having a mold surface shape corresponding to the inner surface shape of a pipe joint is divided into pieces so as to be inserted from the joint part of the pipe joint with the undercut surface in the center, and
In a pipe joint forming mold in which the divided medium mold is further divided into a child medium mold for the undercut surface and a parent medium mold constituting the remainder thereof, the parent medium mold faces outward with respect to the direction in which it regresses to the pipe joint joint. A rod for advancing and retracting the child middle mold is provided with an inclination to the main mold, and the rod is slidably inserted and supported through the parent middle mold and its base so that the child middle mold is separated from the undercut surface by the regression of the parent middle mold. A mold for forming a pipe joint, characterized in that a one-way locking device for temporarily stopping the rod from regressing is provided at the rear of the rod, and the locking device is released by the regression of the master mold, thereby allowing the child mold to retract.