JPH04128020A - Molding method of molding and its mold - Google Patents

Abstract

PURPOSE:To secure an improvement in productivity and reliability in contacting by removing flashes, by a method wherein a mobilized core pin is operated prior to ejection of a molded product. CONSTITUTION:A core pin 27 corresponding to a through hole 2 is fixed its lower end part to a core pin plate 29 by a press plate 28 and the core pin 27 moving vertically along with the core pin plate 29 causes the upper end surface to abut against the undersurface of a retainer plate 16 by mold clamping. Flashes 40 are removed by a method wherein an ejector shaft 13 is raised, a ring 33 and the core pin plate 29 are pushed up by a ring 34 and the tip of the core pin 27 is projected through an insulator 1 to which a molding is formed, in the first action of the ejector shaft 13 removing the flashes 40 clogging an upper opening of the through hole 2 of the insulator 1. The ejector plate 26 is pushed up so that is become higher than pushing up of the core pin plate 29 and the tip of an ejector pin 9 is projected higher than the core pin 27.

Description

[Detailed Description of the Invention] [Summary] Regarding a mold for a molded product having a through hole, a cavity is formed for the purpose of a molding method and the automatic removal of cold stiffness from the through hole at the time of ejection. A core pin is provided that can slide through a first mold plate, and the tip surface of the core pin is wider than the tip surface when the second mold plate contacts the first mold plate and the mold is closed. an eject pin that contacts the flat surface of the first template, fills the cavity with molten resin after the mold is closed, causes the core pin to protrude in the mold closing direction after the mold is opened, and then penetrates the first template; A molding method characterized by ejecting the molded article of the molten resin by a method, a first template in which a cavity is formed, a core pin that slides through the first template; an eject pin that slides through the first template; a second template that has a contact surface at the tip of the core pin when it comes into contact with the first template during mold closing; a first plate to which the rear end is fixed and through which the core pin can slide freely; a second plate to which the rear end of the core pin is fixed; one end is fixed to the first plate and the other end is ejected. an eject rod facing the shaft, a first urging means for urging the first plate in the mold opening direction, and a second urging means for urging the second plate in the mold opening direction; A first ring that is slidably fitted to the eject rod and whose one end protrudes an appropriate amount from the other end of the eject rod when the mold is opened, and is slidable on the tip of the eject shaft that drives in the mold opening/closing direction. a second ring to be fitted; and a third biasing means for biasing the second ring in the mold closing direction and having a biasing force greater than that of the second biasing means and smaller than that of the first biasing means. , by driving the eject shaft. a first stopping means for stopping the second plate pushed in the mold closing direction by the second ring by an appropriate amount of movement; and a first stopping means for stopping the second plate pushed in the mold closing direction by the eject rod by driving the eject shaft. The molding die is characterized in that it includes a second stopping means for stopping the first plate by an appropriate amount of movement.

[Industrial application field]

The present invention relates to a molding method for a molded product having a through hole, such as an insulator for a connector, and a mold thereof.

[Conventional technology]

FIG. 4 is a plan view (a) and a cross-sectional view (0) of an example of the molded product to which the present invention is applied, and FIG. 5 is the main configuration of a conventional molding die for the molded product shown in FIG. FIG. 6 is an explanatory diagram of the ejecting operation of the mold shown in FIG. 5.

In Fig. 4, a rectangular plate-shaped insulator (molded product) ■ made by injection molding of molten resin has many pieces (
It has 16 stepped through holes 2 (in the figure).

In FIG. 5, the mold 3 of the insulator 1 has a movable part 4.
and a fixed part 5.

The movable part 4 mounted on the platen 20 of the molding apparatus includes a movable mold plate 6. The fixed core 7 corresponding to the through hole 2 protrudes into the cavity 8. A plurality of eject pins 9, an eject plate 10 to which the ends of the eject pins 9 are fixed and movable in the template opening/closing direction. A mounting plate 11 to which the movable mold plate 6 is attached via a spacer flock 12, an eject rod 19 fixed to the center of the lower surface of the eject plate 10. Platen 2
It has an eject shaft 13 that penetrates through the mold, faces the eject rod 19, and drives in the mold opening/closing direction.

A plurality of return pins 14 protrude from the movable mold plate 6 toward the eject plate 10, a compression coil spring 15 into which the return pins 10 are inserted urges the eject plate 10 in the mold opening direction, and a restraining plate 18 is attached to the eject pins. 9 is fixed to the eject plate 10.

The fixed part 5 is formed by fixing a plate-shaped fixed mold plate 16 to a mounting plate 17. When the mold is closed, the lower surface of the fixed mold plate 16 covers the cavity 8 of the movable mold plate 6, and also covers each fixed core 7. Abuts against the tip surface.

As shown in FIG. 6, the insulator 1 formed by closing the mold and filling the cavity 8 with molten resin is ejected from the movable mold plate 6 by the eject pin 9 by operating the eject shaft 13. Become.

[Problems to be Solved by the Invention] FIG. 7 is an explanatory diagram of the stiffness that occurs in the insulator l. A burr 40 that closes the hole 2 is generated, and the burr 40 gradually becomes larger due to wear and the like at the tip of the core 7. In particular, when molded products become more precise and a resin with good fluidity is used, the burr 40 becomes even more noticeable.

Such burrs 40 damage the member that fits into the through hole 2, make it impossible to insert the fitting part, and peel off when the fitting part is inserted and adhere to the fitting part, impairing its springiness. , Conventionally, the core pin abutting distance was increased to create a burr 4.
0 is suppressed or removed by seed blasting, manual work, etc., but there is a problem in that the labor and expense involved hinders productivity, especially in mass-produced products.

[Means to solve the problem]

In order to eliminate the above-mentioned problems, the method and mold of the present invention for removing cold burrs from the through hole prior to ejecting the molded product are as follows.According to FIG. 1 showing an embodiment thereof, a cavity 8 is formed. A core pin 27 is provided that can slide through the first template 24, and the tip surface of the core pin 27 is wider than the tip surface when the second template 16 contacts the first template 24 and the mold is closed. Second template 1
After the mold is closed, the cavity 8 is filled with molten resin, and after the mold is opened, the core pin 27 is made to protrude in the mold closing direction, and then the eject pin 9 passes through the first mold plate 24.
A mold forming method characterized by ejecting a molded product l of molten resin, and a cavity 8
The core pin 27 slides through the first template 24, the eject pin 9 slides through the first template 24, and the mold closes. A second template 16 which has a contact surface for the tip of the core pin 27 when it comes into contact with the first template 24, and a first template which fixes the rear end of the eject pin 9 and through which the core pin 27 can freely slide. a second plate 29 to which the rear end of the core pin 27 is fixed; an eject rod 32 having one end fixed to the first plate 26 and the other end facing the eject shaft 13; A first urging means 15 that urges the second plate 29 in the mold opening direction, a second urging means 31 that urges the second plate 29 in the mold opening direction, and a second urging means 31 that is slidably fitted to the eject rod 32. A first ring 33 whose one end protrudes an appropriate amount from the other end of the eject rod 32 when the mold is opened, and a second ring 34 which is slidably fitted to the tip of the eject shaft 13 that is driven in the mold opening/closing direction. second ring 34
30th urging means 3 which urges in the mold closing direction and has an urging force greater than the second urging means 31 and smaller than the first urging means 15.
5 and the first ring 33 by driving the eject shaft 13.
The first stopping means 2 stops the second plate 29 pushed in the mold closing direction by the ring 34 of the ring 34 by an appropriate amount of movement.
3c, and the eject rod 32 is driven by the eject shaft 13.
A second stopping means 23b for stopping the first plate 26 pushed in the mold closing direction by an appropriate amount of movement.

[Effect]

According to the above-mentioned means, the method and mold structure are such that the movable core pin is operated prior to ejecting the molded product, whereby the hole formed to close the through hole of the molded product is poked by the core pin. will be removed.

Therefore, in the molding method and molded product according to the present invention, there is no burr blocking the through hole, and there is no need to remove burr after ejecting.

〔Example〕

The method of the present invention and its mold will be explained below with reference to the drawings.

Fig. 1 is a main configuration diagram of a mold according to an embodiment of the method of the present invention, Fig. 2 is an explanatory diagram of the deburring state of the mold shown in Fig. 1, and Fig. 3 is an ejected diagram of the mold shown in Fig. 1. It is a state explanatory diagram.

In FIG. 1, in which the same reference numerals are used for parts common to those in FIG.

The movable part 22 attached to the platen 20 of the molding device is attached to the mounting plate 11 fixed to the platen 20. Spacer block 23
A movable template (first template) fixed to the mounting plate 11 via
24, etc., and the fixing part 5 has the same structure as the conventional one, and is made by fixing a fixed mold plate (second mold plate) 16 to a mounting plate 17.

The plurality of eject pins 9 have their lower ends fixed to an eject plate (first plate) 26 by a restraining plate 25.

The plurality of core pins 27 corresponding to the small diameter portion of the through hole 2 are connected to the core pin plate (second
The core pin 27 is fixed to the movable mold plate 24. and moves up and down together with the core pin plate 29. Eject plate 26. It passes through the restraining plate 25, and its upper end surface abuts the lower surface of the fixed mold plate 16 when the mold is closed.

A compression coil spring (first biasing means) 15 fitted into the return pin 14 constantly biases the eject plate 26 in the mold opening direction (downward).

The flange 23a protruding inside the middle part of the spacer block 23 is provided with a recess (second stopping means) 23b above the flange 23b for suppressing the vertical movement of the eject plate 26, and below the flange 23a for suppressing the vertical movement of the core pin plate 29. A recess (first stopping means) 23C is provided, and a plurality of compression coil springs (second urging means) 31 are inserted between the flange 23a and the core pin plate 29. is constantly biased in the mold opening direction.

An eject rod 32 hangs down from the center of the lower surface of the eject plate 26, a slidable first ring 33 is fitted to the tip of the eject rod 32, and when the mold is opened, the ring 33 protrudes below the eject rod 32 by an appropriate amount. do.

On the other hand, a second ring 34 opposite to the ring 33 is slidably fitted to the tip of the eject shaft 13, and the ring 34 has a force greater than the total biasing force of the plurality of compression coil springs 31, is biased by a compression coil spring (third biasing means) 35 with a biasing force smaller than the total biasing force of .

In the mold 21 configured in this way, the movable mold plate 24
The insulator 1 is formed by filling the cavity 8 with molten resin.
is ejected by the eject shaft 13 after opening the mold.

The eject operation by the eject shaft 13 is performed by the ring 34.
A first operation (deburring operation) in which the core pin plate 29 is pushed up by a predetermined amount via the ring 33, and a second operation in which the upper end surface of the eject shaft 13 pushes up the lower end surface onto the eject rod 32 and the eject plate 26 is pushed up. (eject operation).

The first operation of the eject shaft 13 to push up and remove the cold material 40 from the upper opening of the insulator through hole 2 is performed from the state in which the lower surface of the core pin plate 29 is in contact with the support plate 11 as shown in FIG. As shown in FIG. 2, the operation of bringing the upper surface of the core pin plate 29 into contact with the lower surface of the flange 23a, that is, the eject shaft 13 rises and the ring 34
This is an operation in which the ring 33 pushes up the core pin plate 29. As a result, the tip of each core pin 27 is, for example, 1 to 2 points larger than the molded insulator 1.
The core pin 27 removes the bulge formed so as to protrude by a non-degree and close the through hole 2.

Note that the insulator 1 should not be lifted up from the cavity 8 during the deburring process, so if necessary, a reverse taper of about 0.5 degree may be provided on the outer periphery of the insulator 1. good.

The second movement of the eject shaft 13 is as shown in FIG.
3, that is, the eject shaft 13 rises and pushes up the eject plate 26 via the eject rod 32. However, the amount of thrust of the eject plate 26 is the same as that of the core pin plate 2.
The recess 2 is formed so that the amount of push-up is larger than that of the eject pin 9 and the tip of the eject pin 9 protrudes from the tip of the core pin 27.
3b and 23C are formed.

Next, when the eject shaft 13 is returned with the mold open, the eject plate 26 and the core pin plate 29 are
The ring 34 is returned to the state shown in FIG. 1 by the biasing force of the coil springs 15 and 31, and the ring 34 is returned to the upward position by the coil spring 35.

〔Effect of the invention〕

As explained above, according to the molding method and the mold of the present invention, the core pin, which is made movable prior to ejecting the molded product, removes the burrs that are formed to block the through holes of the molded product. This eliminates the need for deburring after ejecting, improves productivity, and ensures reliability of fitting parts such as contacts that fit into the through hole.

[Brief explanation of drawings]

Fig. 1 is a main configuration diagram of a mold according to an embodiment of the method of the present invention, Fig. 2 is an explanatory diagram of a state in which the mold shown in Fig. 1 is bulged, and Fig. 3 is an ejected diagram of the mold shown in Fig. 1. State explanatory diagram; Fig. 4 is an example of a molded product to which the present invention is applied; Fig. 5 is a conventional mold for the molded product shown in Fig. 4; Fig. 6 is an example of the molded product shown in Fig. 5. FIG. 7 is an explanatory diagram of the eject operation. In the figure, 1 is an insulator (molded product), 8 is a cavity, 9 is an eject pin, 13 is an eject shaft, 15 is a compression coil spring (first biasing means), and 16 is a fixed mold plate (second 21 is a mold, 23 is a spacer block, 23b is a recess (second stopping means), 23c is a recess (first stopping means), 24 is a movable template (first template), 26 is an eject plate (first plate), 27 is a core pin, 29 is a core pin plate (second plate), 31 is a compression coil spring (second biasing means), 32 is an eject rod, 33 is a first ring , 34 is a second ring, 35 is a compression coil spring (third biasing means), and 40 is a spring. CD-ll1! -2 Translated by Kayo Ishiki C＼- 4 Figure 1 Explanatory diagram of Nibo T-mi-type paring-shaped dragon Figure 2 Y1 (Two-show T-shaped work; 9 Consideration 45” Conventional T-shaped diagram of shaped products for malt (A) (B) F coming 1: Twisting ↑6 Burr 0 Explanatory diagram 3 years old A

Claims (2)

[Claims] (1) A first template (24) in which a cavity (8) is formed.
), and a core pin (27) is provided that can slide through the core pin (27), and the tip end surface of the core pin (27) contacts the first mold plate (24) when the second mold plate (16) comes into contact with the mold when the mold is closed. The core pin (27) is brought into contact with the flat surface of the second mold plate (16) which is wider than the tip surface, and after the mold is closed, the cavity (8) is filled with molten resin, and after the mold is opened, the core pin (27) is moved in the mold closing direction. A molding method characterized in that the molded article (1) of the molten resin is ejected by an eject pin (9) passing through the first mold plate (24). (2) The first template (24) in which the cavity (8) is formed.
), a core pin (27) that slides through the first mold plate (24), an eject pin (9) that slides through the first mold plate (24), and mold closing. A second template (24) having a contact surface at the tip of the core pin (27) when it comes into contact with the first template (24) by
16) and the rear end of the eject pin (9) are fixed and the core pin (
A first plate (26) through which the core pin (27) is slidably penetrated, a second plate (29) to which the rear end of the core pin (27) is fixed, and one end of which is attached to the first plate (26). An eject rod (32) that is fixed and whose other end faces the eject shaft (13), and a first rod that urges the first plate (26) in the mold opening direction.
urging means (15); and a second urging means (15) for urging the second plate (29) in the mold opening direction.
a first ring (33) which is slidably fitted to the eject rod (32) and whose one end protrudes an appropriate amount from the other end of the eject rod (32) when the mold is opened; , a second ring (34) slidably fitted to the tip of the eject shaft (13) that drives in the mold opening/closing direction;
) in the mold closing direction and has an urging force greater than the second urging means (31) and smaller than the first urging means (15), and the eject shaft. A first stopping means (23c) for stopping the second plate (29) pushed in the mold closing direction by the first and second rings (33, 34) by the drive of (13) by an appropriate amount of movement. ), and a second stopping means (23b) for stopping the first plate (26) pushed in the mold closing direction by the eject rod (32) by an appropriate amount of movement by driving the eject shaft (13). A molding die characterized by comprising the following.