JPS59135136A - Resin coating mold - Google Patents

Abstract

PURPOSE:To omit inefficient work for mounting a female screw part to a male screw part, in coating the surface of an insert substrate having a male screw part at the leading end thereof other than the screw part with resin, by performing resin coating in such a state that the boundary part of the screw part and the part to be coated is grasped. CONSTITUTION:In applying resin coating to the surface of an insert substrate 2 having a male screw part 21 at the leading end thereof other than the screw part, the boundary part of the male screw part 21 and the part to be coated is grasped by a part of a mold or a grasping tool 31 to hold the part to be coated in the mold and resin coating is applied to the outer surface thereof. By this method, conventional inefficient work such that the male screw part threaded into the female screw part of a holder is held in the mold can be omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection mold in which the outer peripheral surface of an insert base material is coated with a resin such as vinyl chloride or polyethylene by an injection molding method.

In the case of an insert base material in which the outer circumferential surface of a male threaded insert base material is coated with a resin, for example a male thread sealed pipe joint, conventionally, the insert base material is inserted into a mold for resin coating molding to hold it. By engaging a female threaded jig with the threaded portion of the base material and fixing the female threaded jig within the mold, the male threaded portion was held in the mold as a reference. However, in a mold that simultaneously molds a large number of insert base materials with resin coating in a short period of time, it is difficult to engage such a female threaded jig with the insert base materials in a short period of time and hold it within the mold. It is extremely difficult and therefore very inefficient, requires a long molding takt time, and requires a large number of people to perform the molding work.
I was doing work that cost money.

The present invention eliminates the above-mentioned drawbacks and provides a resin-coated mold that eliminates the work of engaging a female threaded jig every time molding is performed, thereby allowing efficient molding.

The gist of the present invention is a resin coating mold in which a holding portion for holding a male threaded insert base material in the mold is provided at the male thread terminal end, and examples thereof will be described below with reference to the drawings.

FIG. 1 shows a state in which a male threaded insert base material 2 is engaged with a female threaded jig 3 and inserted into a square mold for a conventional vertical injection molding machine. In the cavity space 4 provided between the upper mold 11 and lower mold 12 for resin molding and the insert base material 2, there are runners (not shown) provided in the front upper mold 11 and the lower moxibustion mold 12. Then, resin such as vinyl chloride or polyethylene is filled through the container by an injection molding machine (not shown).

The female threaded jig 3 is inserted into a hole 14 provided in the lower mold 11 and having a shape and size that matches the outer peripheral surface of the female threaded jig 3 while being engaged with the male threaded portion 21 of the insert base material 2. As a result, the insert base material 2 is inserted into the lower mold 11 with the male threaded part 21 as a reference, and then the upper and lower molds are narrowed by moving the upper mold, and the insert base material 2 is inserted into the upper and lower molds 11. ．．
It is fixed within 12.

Next, FIG. 2 shows an embodiment of the present invention. By providing the upper mold 128 and the lower mold 11 with a holding part 30 that contacts the male thread end neck diameter part 22 of the insert base material 2, the insert base material 2 is held in the mold and at the same time the resin is held in the insert base material. This prevents it from flowing out from the outer peripheral surface toward the male threaded portion 21 side. Therefore, the conventional female threaded jig 3 is unnecessary, and there is no need to engage the insert base material 2 one by one, which greatly simplifies the molding operation and shortens the molding time.

Next, Figures 3 and 4 are diagrams showing the second embodiment of the present invention, in which the holding part 30 of the first embodiment is connected to the lower mold 11 and the upper mold 1.
A retaining mask 31, which has a cylindrical shape divided into two parts, is replaceably implanted in each of the molds 2 and 2.The method of fixing it is to form a groove 16 in the upper and lower molds 11 and 12 and insert it, so that the retaining mask floats up during molding. The mold is fixed in the upper and lower division direction by a holding metal fitting 32 and a set holder 33 for prevention. In this case holding mask 3
Material No. 1 is more flexible than the mold, such as an aluminum retainer or a copper alloy, and is more compatible with the insert base material, has a greater effect of preventing resin leakage, and has a good holding function as well as a good effect.

Figures 4 and 5 show an example in which the jig with internal threads is used in combination with the above-mentioned jig with female threads. The holding mask 31 prevents a portion of the resin from leaking out. In this case, the holding mask 31 of the present invention may be made of a flexible material such as resin or rubber, or may be made of a harder material than the mold body. If you take the female threads of the jig 3 with a threaded thread and form them into four parallel parts that match the 8 threads 21 of the insert base material 2, and shorten the time to replace the jig, it will be a thousand years. Outflow of resin inside part 3
1, good effects can be obtained. Further, the holding portion 31 may have a structure that is provided with a wetting device for holding and press-bonding the insert base material 2 at the same time as molding.

As described above, by providing the holding part of the present invention in the mold, the molding time is shortened, and the outflow of fat flows to the two threaded parts. It's good
I can do it. In addition, by incorporating the α-type body and the Torimata-cho nhi, a holder made of a different material from the mold body can be selected, and it can also be replaced due to wear, making it possible to extend the life of the entire mold. Furthermore, it is possible to prevent defects due to damage to the male threaded portion of the insert base material, which has a great effect on improving production efficiency 8 and quality.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing a state in which a threaded insert base material is inserted into a conventional mold, Fig. 2 is a partial sectional view showing one embodiment of the present invention, and Fig. 3 is a partial sectional view showing another embodiment of the present invention. FIG. 4 is a sectional view of a mold taken along line A-A in FIG. 3, and FIG. 5 is a partial sectional view showing another embodiment of the present invention. Explanation of symbols 2... Insert base material, 3... Female threaded jig 4.
...Cavity, 11...Lower mold, 12...Upper mold. 30, 31... Holding part No. 3 / Figure No. 3]A

Claims (1)

[Scope of Claims] (1) In a mold in which an insert base material with five threads is held in a mold and a resin is coated on the outer periphery of the insert base material by an injection molding method, the i! A mold for resin coating, characterized in that the holding portion for holding is provided at the terminal end of the male thread described in iJ. 2. A mold for resin coating according to claim 1, wherein the holding portion is attachable to and detachable from the mold. 3% allowance The resin-coated mold according to claim 2, wherein the holding portion is made of an elastic material. 4.-8 as set forth in claim 2, wherein the holding portion is a resin coating mold 5,%ff made of an aluminum alloy.
46. The mold for resin plugging according to claim 2, wherein the holding portion is made of a material having a higher hardness than the mold. 6. In claim 1, the in-room
1. The base material is a mold for the IU joint.