JPS5913335B2 - Progressive molding method for resin molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a progressive molding method for resin molded products.

In general, resin molded products by injection molding or the like are formed in a single molding process, and therefore thick molded products have the disadvantage of causing so-called sink marks on the surface.

In addition, in conventional movable insulating stands used in hinge-type electromagnetic relays, etc., movable iron pieces or movable contacts were fixed to the resin-molded movable insulating stand by caulking or rivets. This method has the disadvantage that the fixing of the movable iron piece and the movable contact must be performed in separate steps.

The present invention has been made in view of the above-mentioned drawbacks, and involves sequentially feeding a long insert member onto different types of cavities arranged at a constant pitch at the above-mentioned pitch, and sequentially applying resin molding to predetermined locations on the insert member. The first purpose is to prevent sink marks on the surface of the resin molded product, and the second purpose is to mold the movable insulating table with resin and fix the movable iron pieces and movable contacts in the same process. The present invention provides a progressive molding method for resin molded products.

The present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram illustrating the molding method according to the first invention, in which 1 is a stationary mold of an injection molding machine, and has a runner 2 and pin gates 3a, 3b, and 3c.

Reference numeral 4 denotes a movable mold, in which cavities 5a, 5bt5c are arranged in a straight line at equal intervals.

6 is a long insert member, which is inserted into the cavity 5a.
+ 5 b t S c are sequentially moved in the direction of arrow A at a constant pitch of the arrangement interval.

This insert member 6 is first fixed by insert molding a first resin molded product 9a in the first cavity 5a.

The resin molded product 9a is naturally ejected from the first cavity 5a by moving the movable mold 4 in the direction of arrow B and opening the mold, provided that the insert member 6 is fixed in the vertical direction.

Further, the resin molded product 9a is provided with a small hole (not shown) that passes through the resin molded product 9a vertically.

Next, the insert member 6 is sent in the direction of arrow A while being slightly lowered in the direction of arrow B, the resin molded product 9a is positioned above the second cavity 5b, and the movable mold 4 is moved in the direction opposite to arrow B. The mold is closed, and resin is injected from the pin gate 3b.

The insert member 7 is stored in the second cavity 5b in advance, and the resin injected from the pin gate 3b flows through the small hole of the first resin molded product 9a and the small hole (not shown) of the insert member 7. , second resin molded product 9b
is formed.

Moreover, resin molded product 9a. 9b, a small hole is left in the insert member 7 that passes through it vertically.

The resin molded product 9b formed in this way is the resin molded product 9a.
, and the insert member 7 are discharged from the second cavity 5b by opening the movable mold 4 as described above, and are sent onto the third cavity 5c, and close the movable mold 4 and pass through the pin gate. Inject the resin from 3c.

An insert member 8 is stored in advance in the third cavity 5c, and the resin injected from the pinhole 3c flows through the small hole and the small hole (not shown) of the insert member 8, and the resin is injected into the third resin molded product 9c. is formed.

The resin molded products 9a, 9b, and 9c molded in this way are integrated via the insert members 6, 7, and 8, and are sequentially fixed at predetermined positions of the insert member 6 at regular intervals for each injection molding, After being discharged from the molds 1 and 4, the insert member 6 is appropriately cut to form a single piece.

Note that in this embodiment, the capacity 5a.

Although sb and 5c are shown as being formed in one movable mold 4, they may be formed in separate molds, and in this case, the resin molded products 9a, 9b, t9c are molded with different types of resin. It is possible to do so.

Fig. 2 shows another embodiment of molding a thick resin molded product, in which a slightly smaller resin molded product 11a is first fixed at a predetermined location of a long insert member 100 by insert molding, and then the entire outer peripheral surface is fixed. is coated with resin 11b to form a resin molded product of a predetermined shape.

That is, in this example, since the wall thickness of the second molded product is particularly thin, there is no risk of sink marks occurring on the surface.

In addition, when high-grade resin such as heat resistance is required, high-grade resin is used only for the coating resin 11b, and the internal resin molded product 11
For a, an inexpensive resin may be used.

Figures 3, 4, and 5 explain the forming method according to the second invention, in which 12 is a hoop material made of a highly conductive metal material, in which slits 12a and small holes 13at 13b are punched out in advance, and slits 12a and small holes 13at 13b are punched out in parallel. The four plate-shaped portions 14 are later cut to form a movable contact.

This hoop material 12 has four movable insulating stands 15 fixed at regular intervals at predetermined locations on the plate-like part 14 by insert molding. A groove portion 17 and through holes 18, 18 are formed.

The movable insulating table 15 moves the hoop material 12 one pitch in the direction of arrow C, that is, the movable insulating table 15' at the right end in the figure is sent a distance to a cavity (not shown) position where resin molding will be performed next.

The movable iron piece 19 is stored in advance in the cavity, and the second molding resin 21 is applied to the groove 17 of the movable insulating table 15, the through holes 18, 18, and the small hole 2 of the movable iron piece 19.
The movable insulating base 15 and the movable iron piece 19 are integrated with each other by being filled with the movable insulating base 15 and the movable iron piece 19.

The movable insulating table 15 is molded in four pieces at a time as described above, and later the plate-shaped portion 14 of the hoop material 12 is cut and separated, and a movable contact (not shown) is inserted into the small hole 13a.
Secure with caulking.

Alternatively, the plate portion 14 may be cut after the movable contact is caulked and fixed in the small hole 13a.

The movable insulating stand 15 manufactured in this way is used as a movable part of a contact mechanism such as a well-known hinge type electromagnetic relay.

Furthermore, in this embodiment, the number of movable insulating tables 15 molded in one resin molding is not limited to four, and each cavity may be formed in one mold.
Alternatively, a different mold may be used.

As is clear from the above description, according to the first invention, different types of cavities are arranged at regular intervals, and a long insert member is intermittently fed over the cavities at regular intervals, and each The intermediate resin molded product insert-molded in one cavity is further insert-molded in the next cavity, and resin molding is sequentially applied to predetermined parts of a long insert member, so it is possible to simply fix the insert member and place it in the mold. The resin molded product can be discharged simply by opening the mold.

Moreover, there is no thick wall part created in one molding process.
There is no problem of sink marks on the surface of the molded product, and the high-grade resin can be molded only in the areas where it is needed, reducing costs.

According to the second invention, in addition to the advantages of the first invention, a movable insulating table having a through hole in the hoop material in at least one of the cavities arranged at regular intervals is fixed. In addition, the movable insulating base and the movable iron piece are integrated in other cavities of the above cavities, so that unlike conventional molding of the movable insulating base and the movable iron piece or movable contact Fixation with child (mainly by caulking and rivets)
The molding of the movable insulating table, which used to be done in a separate process, can be done in the same process, which simplifies the manufacturing process.

[Brief explanation of drawings]

FIG. 1 is an explanatory schematic diagram showing one embodiment of the molding method according to the first invention, FIG. 2 is a perspective view of a molded product obtained by another implementation of the molding method according to the first invention, and FIG. A plan view illustrating the molding method according to the second invention, FIG. 4 is a front view of FIG. 3,
FIG. 5 is a sectional view taken along the line V-■ in FIG. 3. 5at5bt5c...Cavity, 6...Insert member, 9a, 9b, 9c...Resin molded product, 10...
・Insert member, 11a...resin molded product, 11b・
... Coating resin, 12... Hoop material, 15... Movable insulating stand, 19... Movable iron piece.

Claims (1)

[Claims] 1. An intermediate resin molded product that is insert-molded in each cavity by arranging different types of cavities at regular intervals and intermittently feeding a long insert member onto the cavities at the above-mentioned intervals. A progressive molding method for resin molded products, characterized in that insert molding is further performed in the next cavity. 2. After arranging different types of cavities at regular intervals, and fixing a movable insulating table having a through hole in the hoop material in at least one of the cavities at regular intervals by insert molding at the above-mentioned regular intervals,
The hoop material is intermittently moved to another cavity at regular intervals, and the movable insulating stand is positioned on the movable iron piece previously stored in this cavity so that its through hole matches the small hole of the movable iron piece. A resin molded product characterized in that the through hole and the small hole are filled with resin through insert molding to integrate the two, and the hoop material is further cut into a predetermined shape of a movable contact. progressive molding method.