JPH0126420Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spruce lag pulling device for pulling out a spruce lag left in a sprue of a mold after injection molding.

For example, in injection molding equipment for shoes such as boots,
A mold consisting of a bottom mold, a pair of side molds, and a foot mold covered by the bottom mold and side molds is used, and the bottom mold is equipped with a small diameter sprue that communicates between the injection nozzle of the injection machine and the cavity of the mold. As a result, a sprue slug remains inside the sprue after injection molding. Traditionally, the spruce lugs were cut from the molded boot by opening the mold, and then the worker grabbed the spruce lugs and pulled them out from the sprue.
The gripping distance of the spruce lugs is short, resulting in poor work efficiency.Furthermore, the spruce lugs strongly adhere to the inner circumferential surface of the sprue, so the gripping portion may break, making it difficult to always pull out the spruce lugs in a stable manner. There is a problem that the work cannot be done.

In view of the above, the present invention has been developed by molding a pull-out rod that is connected to the spruce lug during injection molding, and using pressurized air to pull out the spruce lug through the pull-out rod, which is highly efficient and stable. An object of the present invention is to provide a spruce slug pulling device capable of performing a spruce slug pulling operation.

According to the present invention, the above object is achieved by providing a first small diameter hole communicating with the sprue at one end, a second small diameter hole communicating with the injection nozzle of the injection machine at the other end, and a large diameter hole between the small diameter holes. a cylinder having both ends thereof and attached to the mold; a hollow cylindrical part having both ends slidably fitted into the first and second small diameter holes and having a through hole larger in diameter than the sprue, and an outer circumferential surface of the hollow cylindrical part; a piston having a protruding flange portion that partitions the inside of the large diameter hole into a first air chamber on the mold side and a second air chamber on the injection nozzle side; during injection molding, the piston communicates with the second air chamber; A cavity for forming the drawn rod is formed by the cooperation of the second small diameter hole and the through hole in contact with the mold, and when drawing the spruce slug, the cavity is communicated with the first air chamber to separate the piston from the mold. The air chamber is connected to the first
A pneumatic source in communication with the small diameter hole; and a spruce slug extraction device.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
A pair of side molds 3, 3 which are connected to each other so as to be openable and closable via a hinge 2, a bottom mold 6 which is connected to one of the side molds 3 so as to be openable and closable via a hinge 5, and the side molds 3 and the bottom. It consists of a foot mold 4 covered by a mold 6, and a sprue 7 is perforated in the bottom mold 6, one end of the sprue 7 is open on the outer surface of the bottom mold 6, and the other end is connected to both sides of the mold 3 and the foot mold. 4 and a cavity 8 formed by the bottom mold 6.

Further, an injection machine 9 is disposed around the outer periphery of the mold 1, and its injection nozzle 10 can be positioned coaxially with the sprue 7 of the bottom mold 6.

The bottom mold 6 is provided with a pneumatic spruce lug pulling device 11 for forming a pulling rod to be connected to the spruce lug during boot molding, as described below.

The device 11 includes a cylinder 12 and a piston 13 slidably connected thereto, the cylinder 12 having an end wall 14 at one end, a cylinder body 16 having an opening 15 at the other end, and a seal ring 17 in the opening 15. The head part 20 has a small diameter part 18 that is fitted through the opening 15, and a large diameter part 19 that comes into contact with the end surface of the opening 15. The cylinder 12 is
It is fixed to the bottom mold 6 by a plurality of mounting screws 23 that pass through the head portion 20, the peripheral wall of the cylinder body 16, and the bottom mold injection plate 21, and are screwed onto the bottom mold body 22.

A first small diameter hole 251 is formed at the center of the end wall 14 of the cylinder body 16 and communicates with the sprue 7 by a bushing 24 fitted therein.
A second small diameter hole 252 that can communicate with the injection nozzle 10 is formed at the center of the injection nozzle 10, and these small diameter holes 251, 25
2 and the large diameter hole 26 on the inner periphery of the cylinder body 6 are arranged coaxially.

The piston 13 includes a hollow cylindrical portion 27 whose both ends are slidably fitted into the first and second small diameter holes 251 and 252, respectively, and a seal ring protruding from the outer peripheral surface of the intermediate portion of the hollow cylindrical portion 27. It consists of a flange portion 29 that is slidably fitted together via a flange portion 28. Large diameter hole 26
The inside is divided into a first air chamber A on the bottom mold 6 side and a second air chamber B on the injection nozzle 10 side by a flange part 29, and the cylinder body 1 is in communication with both chambers A and B.
A pair of through holes 30 and 31 are bored in the peripheral wall of 6. A pneumatic source 33 is connected to the through holes 30 and 31 via a switching valve 32.

The through hole 34 of the hollow cylindrical portion 27 has a draft angle that gradually increases the inner diameter from the bottom mold 6 side toward the injection nozzle 10 side. Second small diameter hole 252 and hollow cylinder part 27
A seal ring 35 is interposed between them.

A plurality of communication grooves 36 for communicating between the first air chamber A and the inside of the first small diameter hole 251 are formed at equal intervals in the circumferential direction on the outer peripheral surface of the end of the hollow cylindrical portion 27 on the bottom mold 6 side.

Next, to explain the operation of this embodiment, during injection molding, the mold 1 is closed as shown in FIG.
Furthermore, in the spruce lag extraction device 11,
As shown in FIG. 2, pressurized air is introduced into the second air chamber B from the air pressure source 33 via the switching valve 32, and the first air chamber A is opened to the atmosphere, and the piston 13 is moved toward the bottom mold 6 side. Move one end surface of the bottom mold injection plate 21
The other end surface is placed in the second small diameter hole 252. As a result, a cavity 37 for forming a drawn rod is formed in the cylinder 12 by the second small diameter hole 251 and the through hole 34 of the piston 13.
In this case, each communication groove 36 of the piston 13 is located in the first small diameter hole 251, and each communication groove 36 is located in the first air chamber A.
There is no communication with the

In the injection machine 9, the injection nozzle 10 is moved so that its tip end surface contacts the end surface of the cylinder 12 of the spruce slug pulling device 11, and the inside of the injection nozzle 10 is communicated with the second small diameter hole 252. Then, the heated and fluidized synthetic resin is injected from the injection nozzle 10, and is injected into the cavity 8 of the mold 1 through the second small diameter hole 252, the through hole 34, and the sprue 7 to mold the boot. During this molding, the third
Spruce lug 3 inside sprue 7 as shown in the figure.
8 is also a cavity 37 in the cylinder 12
Inside is a pull-out rod 3 connected to the spruce lug 38.
9 are respectively molded. The pull-out rod 39 includes an enlarged head 40 corresponding to the second small diameter hole 252 and a tapered shaft portion 41 corresponding to the through hole 34.

When opening the mold 1 after forming the boot, the bottom mold 6 is first rotated via the hinge 5 in the direction of the arrow a in FIG. The connecting portion 42 is pulled off from the boot.

After that, the air pressure source 33 connects the first
Pressurized air is introduced into the air chamber A, and the second air chamber B is opened to the atmosphere to separate the piston 13 from the bottom mold 6. As a result, the hollow cylindrical portion 2 of the piston 13
7 end face presses the stepped portion 43 between the enlarged head 40 and the tapered shaft portion 41, so that the enlarged head 40 and the second small diameter hole 25
The close contact between the sprue lug 2 and the inner circumferential surface of the sprue 7 and the close contact between the spruce lug 38 and the inner circumferential surface of the sprue 7 are released, and the spruce lug 38 is pulled by the pull-out rod 39 and begins to be pulled out from the sprue 7.

When the first air chamber A communicates with the first small diameter hole 251 through each communication groove 36 due to the subsequent movement of the piston 13, pressurized air is also introduced into the first small diameter hole 251. As a result, a pushing force is applied to the stepped portion 44 between the tapered shaft portion 41 of the pull-out rod 39 and the spruce lug 38, so that the pull-out rod 39 is ejected from the through hole 34 to the outside, and accordingly, the spruce lug 3
8 is also pulled out from the sprue 7, and the work of pulling out the spruce lug 38 is completed. As shown in FIG. 4, the piston 13 stops moving forward when the flange portion 29 abuts against the inner wall surface of the large diameter hole 26 on the second small diameter hole 252 side.

Thereafter, a second
Pressurized air is introduced into the air chamber B, and the first air chamber A is opened to the atmosphere to return the piston 13 to its original position.

As described above, according to the present invention, during injection molding, a pull-out rod that is connected to a spruce lug is molded, and when the spruce lug is pulled out, pressurized air is first applied to the pull-out rod, the inner peripheral surface of its cavity, the spruce lug, and the sprue. Since the spruce lug is released from the inner circumferential surface and then pulled out together with the pulling rod, the spruce lug can be pulled out efficiently and stably.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of an injection shoe making device equipped with a spruce lug pulling device according to the present invention, FIG. 2 is an enlarged cross-sectional view taken along the lines of FIG. 1, and FIG. is a sectional view similar to FIG. 2 showing the spruce lug and the drawn rod in a formed state;
FIG. 4 is a sectional view similar to FIG. 2, explaining the operation of the piston. A, B...first and second air chambers, 1...mold, 7
... Sprue, 9 ... Injection machine, 10 ... Injection nozzle, 11 ... Spruce slug extraction device, 12 ...
...Cylinder, 13...Piston, 251, 252
...First and second small diameter holes, 26...Large diameter holes, 27...
...Hollow cylindrical portion, 33...Pneumatic pressure source, 34...Through hole,
36... Communication groove, 37... Cavity, 38...
Spruce lug, 39...pull rod.

Claims (1)

[Scope of utility model registration request] A spruce lag pulling device for pulling out the spruce lug through the drawing rod by molding a drawing rod in series with the spruce lug molded in the sprue of a mold during injection molding, the device having one end at one end. A cylinder attached to the mold, having a first small diameter hole communicating with the sprue, a second small diameter hole communicating with an injection nozzle of an injection machine at the other end, and a large diameter hole between the small diameter holes. a hollow cylindrical portion having both ends slidably fitted into the first and second small diameter holes and having a through hole larger in diameter than the sprue; a piston having a flange portion that partitions the inside into a first air chamber on the side of the mold and a second air chamber on the side of the injection nozzle; communicating with the second air chamber during injection molding to connect the piston to the mold; The second small-diameter hole and the through hole cooperate to form a cavity for forming the drawn rod, and when the spruce slug is drawn, it is communicated with the first air chamber after the piston is separated from the mold. , a pneumatic pressure source that communicates the first air chamber with the first small-diameter hole via a communication groove on the outer circumferential surface of the hollow cylindrical portion;