JPH0254770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides an insert part manufacturing apparatus that fixes the insert part in a cavity during insert molding and prevents the insert part from being exposed from the molded part by fixing pins or the like. It is related to.

Structure of conventional example and its problems Conventionally, in this type of molding die, the insert product is fixed with a movable insert product presser pin with a spring, and the movable insert product presser pin with a spring prevents the insert product from being damaged by pin marks. In order to prevent exposure from the molded product, it has a shape that is pushed out to the outside of the mold by the resin pressure during molding, and the spring of the spring-equipped movable insert product holding pin is used to hold the insert product and the spring after molding. It had a structure that had two functions: to return the movable insert product holding pin to its original position.

However, considering that the spring-equipped movable insert product retainer pin is pushed out of the mold by the resin pressure during molding, it is better to have a weaker spring force. Considering that the spring-equipped movable insert holding pin returns to its original position due to the spring force, the spring force should be strong, and it is extremely difficult to set a spring that satisfies these two contradictory actions. Moreover, in the case of a multi-cavity mold, the operation may be unstable, and it is difficult for the spring to satisfy the two contradictory operations.

Purpose of the Invention In order to eliminate such conventional drawbacks, the present invention provides that the spring of the spring-equipped movable insert product holding pin serves only to hold down the insert product, and after molding the spring-equipped movable insert product holding pin, By returning the spring to its original position using an independent pressing weight of a separate mechanism, the above-mentioned contradiction is eliminated, and the operation of the spring is stabilized and the setting is facilitated.

Structure of the Invention In order to achieve the above-mentioned object, the present invention provides a pressing weight that is placed on the upper end of a movable insert product holding pin with a spring and presses the movable insert product holding pin with a spring in the protruding direction, and is movable up and down against the upper die. In addition, when the lower mold and the upper mold of the molding die overlap, the press weight is released from pressing the insert presser pin.

By providing this pressing weight, the force of the pressing part such as a spring provided on the spring-equipped movable insert product holding pin can be made weak, and insert molding can be performed with good quality.

DESCRIPTION OF EMBODIMENTS An insert component manufacturing apparatus according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Figure 1 shows the upper mold 1 and lower mold 2 of the molding die before molding are open, and Figure 2 shows the insert 3 installed in the molding cavities 1a and 2a of the upper mold 1 and lower mold 2. and the device is closed.

In the figure, an upper mold 1 is arranged to be movable in opening and closing with respect to a lower mold 2, and molding cavities 1a and 2a are provided on the lower central surface of the upper mold 1 and the upper central surface of the lower mold. A movable insert holding pin 4 with a spring is arranged in the center of the cavity 1a so as to be projected by a spring 6.
A pressing weight 7 is disposed on the upper surface of the upper mold 1 and comes into contact with the head of a movable insert presser pin 4 with a spring. This press weight 7 is connected to the upper end of a return pin 8 that is incorporated so as to vertically penetrate the upper die 1, and a spring 9 is further provided on the upper surface of the press weight 7 to bias the press weight 7 downward. A spacer 10 is provided beside the pressing weight 7 to ensure movement of the pressing weight 7.

With such a configuration, when the upper mold 1 and the lower mold 2 shown in FIG. 1 are opened, the molding cavity 2a of the lower mold 2 is opened.
Place the insert 3 inside the mold, close the upper mold 1 and lower mold 2 as shown in FIG.
Press it to hold it in place.

At this time, the lower end of the return pin 8 hits the lower mold 2 and the pressing weight 7 cannot move downward, so it does not follow the downward movement of the upper mold 1 but moves upward, and the movable insert product holding pin 4 with a spring The upper end of is free. Thereafter, the molding cavities 1a, 2a of the upper mold 1 and lower mold 2 are filled with resin 5 under high pressure from the molding machine, and the resin pressure causes the movable insert product holding pin 4 with a spring to spring upwardly of the upper mold 1. It is pushed out against the elastic force of 6.

FIG. 3 shows this, and after the molding is completed, the above-mentioned movable insert product holding pin 4 with a spring is attached.
tries to return to its original position by the spring 6 at the head, but in many cases, such as in a multi-cavity mold or when sufficient resin pressure is not applied, the spring 6 alone is often insufficient.

However, as shown in FIG. 4, by pushing the spring-equipped movable insert product holding pin 4 downward with a pressing weight 7 that utilizes the opening and closing of the device, the spring-equipped movable insert product holding pin 4 can be reliably returned to its original position. It can be returned to its position.

Effects of the Invention By using the spring-equipped movable insert presser pin that has a forced return mechanism using a pressing weight as described above, it is possible not only to set the spring to a more optimal condition, but also to ensure that the spring is The attached movable insert holding pin returns to its original position, allowing the production of high-quality insert parts.

[Brief explanation of drawings]

1 to 4 are cross-sectional views showing the operation of an insert component manufacturing apparatus according to an embodiment of the present invention. 1... Upper die, 2... Lower die, 3... Insert product, 4... Insert product holding pin, 7... Pressing weight.

Claims (1)

[Claims] 1 A movable insert product holding pin with a spring whose end protrudes is provided in the molding cavity of the upper mold of the molding die, and a pressing weight that presses the movable insert product holding pin with the spring in the protruding direction is placed above and below the upper mold. Manufacture of an insert part configured to be movable and configured so that when the lower mold of the molding die and the upper mold overlap, the pressure of the pressing weight on the spring-equipped movable insert product holding pin is released. Device.