JPS60240420A - Bonding of insert to be pressed into molten resin - Google Patents

Abstract

PURPOSE:To improve molding efficiency and prevent generation of cracks in molding near insert by pushing up and pressing insert into molten resin from a concave part of a die before the cooling and curing of molten resin filled inside a cavity. CONSTITUTION:Inserts 103, 103... with an internal screw formed are introduced into concave parts for inserts 104, 104... on a movable die side 102 and then the die is clamped. Next, molten resin is filled into a cavity 105 through a spool bush 107 connected to a nozzle on an injection molding machine. Then under the action of a hydraulic ejector 112, the inserts 103 are pushed up into the molten resin by an ejector pin 100 and then are pressed into a molding 113. This method eliminates the use of supplementary metal fittings and saves manual work such as screwing-in and removal. Furthermore, a differential in coefficient of expansion between the inserts 103 and resin is slightly moderated and the occurrence of cracks near the insert 103 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of joining an insert by completely press-fitting the insert into a molten resin injection-molded into a cavity of a mold.

``Prior art'' As shown in Figure 4 @), ←), a molded product 1 has internal threads 2
If there is a small insert 2 (small object embedding metal fitting) with 1 formed thereon, the threaded part of the insert 2 should be inserted into the threaded part of the insert 2 as shown in FIG. The external threads 31'i of the auxiliary fittings 3 are screwed together. (See Figure 5?) Then, insert the auxiliary metal fittings 3 into the elongated holes 51, 51... formed in the upper part of the movable side mold plate 5 (movable mold) and Nijief tabi/6, and insert the small insert. Set it so that 2 stands out from the party/grain.

Next, to close the mold, the fixed side mold @ 4 (the insert 2 is located in the cavity part 41 of the fixed mold 9).

In this state, the molten resin is injected into the mold, and after cooling and solidifying,
Fully open the mold and take out the molded product 1. (See Fig. 6) Then, # remove the auxiliary position tool 3 from the molded product 1.

As mentioned above, it takes time to set an insert with a threaded part into the cavity of a mold, which increases the molding cycle time, and it also takes a considerable amount of time to remove the auxiliary fitting from the insert. , which impairs the molding efficiency.

Furthermore, if the insert comes off during the mold closing process during molding, there are many problems such as damage to the mold. In addition, since the insert is fixed to prevent it from shifting or falling off after molding, cracks may occur due to the difference in thermal expansion coefficient between the insert and the plastic material.

``Problems to be Solved by the Invention'' The technical problem of the present invention is to eliminate the need for a drawing aid even when embedding a small insert with an internal thread, thereby improving overall molding efficiency. It is an object of the present invention to provide an insert press-fitting method which can further increase the size of the insert without damaging the mold, and can prevent cracking around the insert due to the inserted insert.

"Structure of the Invention" The structure or technical means of the present invention for solving the above-mentioned technical problems is as follows.

Corresponding to one mold in which the cavity was formed, one or more recesses are formed in the other mold, an inserter of a desired shape is inserted into the recess, and then the above-mentioned process is performed. After the mold is closed, the insert is press-fitted into the molten resin by an appropriate means before the molten resin filled in the cavity is cooled and solidified. It's in the way the inserts are connected.

``Effects of the Invention'' Since the auxiliary metal fittings are used to press-fit the insert before the molten material injected into the cavity is cooled and solidified, there is no need to remove the auxiliary metal fittings from the product or to install molded parts. The efficiency of the molding cycle was further improved by eliminating all the troublesome labor.

Also, unlike the case where the insert is set in advance in the cavity, some of the melting heat is injected into the cavity and absorbed by the mold, so the difference in thermal expansion coefficient between the insert and the resin is somewhat is alleviated, and cracks around Innosate can be prevented. "Example" Hereinafter, an example of the method of the present invention will be described based on FIGS. 1 and 2.

Reference numeral 100 denotes an ejector turbine which is raised in a dynamic range type 102 by a hydraulic ejector 101, and a recess m104' is formed at the tip of the ejector turbine 100 to be inserted into a small inserter 103'.

Reference numeral 105 designates a cavity portion of a fixed mold 106, and the cavity portion 105 is filled with a molten material (molding material) to form a product.

In the drawing, 107 is a sprue bush, 108rJ sprue lock pin, 109 is a spacer block, 110
The fixed mold 106 is mounted on a plate, and 111 is Bl'! II
Mounting l, 1.12 of the mold 102 is a hydraulic ejector. "Function" After the mold is opened, the insert recess 104 on the movable mold 102 side
．． Insert the inserts 103 and 103 into the holes 104 and 104, respectively (see Figure 1), and then close the mold.

Next, when the cavity 105 is filled with the molten material through the sprue bush 107 that protrudes from the nozzle of the injection molding machine, the inserts 103, 103 are pushed up into the molten material by the operation of the hydraulic ejector 112 and molded. Item 11
Press in the internal trap of 3. (See Figure 2) After opening the mold, a product as shown in Figure 3 can be obtained.

As described above, according to the method of the present invention, the auxiliary metal fittings can be made longer and the trouble of screwing in and removing them is eliminated.

In addition, in FIGS. 1 and 2, the insert set in the recessed insert mold at the tip of the ejector turbine is 1 for illustration purposes.
However, by setting up multiple pieces, continuous injection molding is possible, increasing the efficiency of the molding cycle.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a specific example of the method of the present invention, in which the left half shows the entire state without the insert inserted, and the right half shows the state with the insert inserted. FIG. 2 shows a state in which an insert is press-fitted into a molded article by the method of the present invention. Figure 4 shows the molded product, and (a) and (b) show the cross-sectional view and bottom view of the molded product. Figure 5 (() shows the insert and the auxiliary fitting used in the conventional method, (b), e: 9 is a sectional view S showing the insert screwed into the auxiliary fitting. Figure 6 shows the insert and the auxiliary fitting used in the conventional method. 1oO: Eject turbine 102: Movable metal fitting 103: Insert 104: Insert recess 105: Cavity portion 113: Molded product Fig. 3 Fig. 4 (A) (B) 5th Figures (A) (B) (C) Figure 6 Procedural amendment (method) % formula % 1. Indication of the case 1982 Patent Application No. 966-16 2 Name of the invention Shimuro insert press-fitted into molten resin Address: 3-18-3 Fukuya, Urawa-shi, Saitama Prefecture Postal code: 105 1t Address: 2-12-10-5 Shinbashi, Minato-ku, Tokyo Date of amendment order July 11, 1980 6 Specification subject to amendment "Brief explanation of the drawings" column 7 Contents of the amendment As stated in the attached sheet, 7. Contents of the amendment (1), page 6 of the specification, "4. Brief explanation of the drawings" section, explanation of Figure 3. It is described as follows. Figure 3 is a sectional view of the device according to the conventional method.

Claims (1)

[Claims] One or more recesses are formed in the other mold corresponding to one mold in which the cavity is formed, an insert of the desired shape is inserted into the recess, and then the above-mentioned mold is inserted into the recess. After the mold is closed, the insert is press-fitted into the molten resin by an appropriate means before the molten resin filled in the cavity is cooled and solidified. How to join.