JPH0325333B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an injection mold, and in particular, the mold is clamped slowly and the pin terminal is held by the core bar, and the pin terminal is The present invention relates to an injection mold that can perform accurate molding.

[Conventional technology]

The plug shown in Figure 5 C is based on the unified European standard (CEE).
No. 7 standard), and consists of a pair of pin terminals, a plug body 3 injection-molded from plastic resin, and a cord 1 connected to the rear end of the pin terminal 2.

Furthermore, to explain the pin terminal 2 in detail, as shown in FIG.
A and cord connection part 2B where cord 1 is connected
, a connecting portion 2A, and a terminal shaft 2C that connects the cord connecting portion 2B. Also, this pin terminal 2
When used in the plug shown in FIG. Therefore, the insulating holder 3a must be formed on the pair of pin terminals 2 before the plug body 3 is molded.

Conventionally, injection molds shown in FIGS. 4A and 4B have been used to form the insulating coating 4 and the insulating holder 3a for such a pair of pin terminals 2.

Figure 4A is a front sectional view, and Figure 4B is a
It is a top view of a movable mold.

The fixed mold 11 is fixed to the fixed mounting plate 10 with bolts (not shown) or the like, and a cavity 12 is provided at the bottom of the fixed mold 11.
has a half-shaped plug terminal as shown in FIG. 5B. ) and which receives the core metal 40 provided in the movable mold 20 (one end of the core metal support part 13 has a tapered part 14).
is formed. Additionally, a sprue 15 is attached to the fixed mounting plate 10 for injecting plastic resin.
A runner 16 is provided on each of the fixed molds 11.

The movable mold 20 that moves up and down and matches the fixed mold 11 to form the cavity 12 is attached to the movable mounting plate 1.
0' via a spacer block 10A with bolts or the like. The movable mold 20 includes a cavity 21 having a symmetrical shape with the fixed mold 11, and a core metal receiving part 22 (one end of the core metal receiving part has a tapered part 24 like the core metal receiving part 13 of the fixed mold 11). ), and further includes a gate 23 for flowing plastic resin into the cavities 12 and 21;
A small hole 25 is formed into which the ejector pin 30 is inserted, and the ejector pin 30 has a spring 32 around its one end and is fixed to the ejector plate 31. The ejector plate 31 is fixed to a drive means 33 for moving the movable mold up and down.

The core metal 40 that holds the pin terminal 2 is a fixed mold 11
In order to be inserted into the core metal receiving parts 13 and 22 of the movable mold 20, it has a tapered part 44 that fits the taper parts 14 and 24 of the fixed mold 11 and the movable mold 20, respectively. Holes 41 (location positions of the pin terminals 2) are formed inside at predetermined intervals, and in the holes 41 there are engagement pairs having curved portions that engage with the contact portions 2A of the pin terminals 2. 42 and an engaging pair 42
On the other hand, a spring 43 is built in to absorb the pressing force from the cavity 21 side. Here, the hole 41,
The engaging portions 42 and the springs 43 are formed at predetermined intervals and at predetermined angles so as to comply with European unified standards.

In the above configuration, a method of forming a plug terminal will be explained.

First, insert the contact portion 2A of the pin terminal 2 into the hole 41 of the core bar 40 (when inserting the pin terminal into the core bar 40, a pressing force is applied to the engaging body 42 that contacts the pin terminal, although not shown). Since a pressure release mechanism is provided to prevent the pin terminal from being removed from the core metal 40 by the force of the spring 43).

Second, after inserting a predetermined number of pin terminals 2 into the core metal 40, the core metal 40 is inserted into the core metal receiving part 2 of the movable mold 20.
2 to release the pressure release mechanism of the core metal 40.

The movable mold 20 is raised by the drive means 33 and clamped with the fixed mold 11.

Third, plastic resin is applied from the plastic resin injection part (not shown) to the sprue 15 and the runner 1.
6. The mixture is injected into the cavities 12 and 21 through the gate 23, and the insulating holder 3a and the insulating coating 4 are formed on the pair of pin terminals to form plug terminals.

[Problem that the invention seeks to solve]

However, in conventional injection molds, the fixed mold 11 and the movable mold are clamped at a constant speed and with a constant pressure, so the core bar 40 holding the pin terminal Because more pressure than necessary is applied shockingly to the mold cavity, the pin terminal may not be able to maintain the specified position, distance, and angle between the mold cavity and the core metal, and there is a risk that the insulation holder and insulation coating will not be formed accurately. , and as mentioned above, constant speed,
Since the mold is clamped with a constant pressure, the mold and the core metal will wear out, and the position where the pin terminal is held between the core metal and the cavity will not be constant. However, the insulating holder and the insulating coating are not formed accurately, and the core metal and the mold must be replaced in a short period of time.

[Means and actions for solving problems]

The present invention has been made in view of the above, and is capable of accurately forming an insulating holder and an insulating coating while maintaining a predetermined distance and angle with respect to a pin terminal without causing severe wear of the core metal etc. Therefore, an injection mold is provided in which an elastic mechanism is provided to change the speed and pressure of clamping the mold against the pin terminal when the mold is clamped.

〔Example〕

Hereinafter, one embodiment of an injection mold according to the present invention will be described in detail based on the attached drawings.

1, 2, and 3 show an embodiment of an injection mold according to the present invention.

The fixed mounting plate 100 has a sprue 101 in the center of the upper surface thereof, into which plastic resin is poured;
It has a runner 102 and an engagement recess 103 on the lower surface.
is formed. Furthermore, cam 1 is installed on the fixed mounting plate.
05 is fixed with bolts (not shown) etc.
A tapered portion 106 is formed inside the lower tip of the cam 105 . The fixture 110 has a cavity 114 for molding the pin terminal 2, and a core metal receiving groove 115 is connected to the cavity 114. Core metal receiving groove 11
A pin 116 and a spring 117 that applies an outward biasing force to the pin 116 are built into one side of the pin 5 . Pin 116 of core metal receiving groove 115
A slide plate 118 that is movable by a predetermined distance is provided on the opposite side of the measuring section where the metal core receiving groove 115 is provided. A taper 119 is formed on the opposite surface of the slide plate 118 that constitutes the inside of the side wall of the core metal receiving groove 115.
As shown in FIG. 7, a recess 126 formed on the slide plate 118 and a protrusion 120 formed on the fixed mold 110 are slidably engaged. As a means for stopping the sliding of the slide plate 118, a spring 122 is inserted into a hole 121 provided in the fixed mold 110, a steel ball 123 is interposed at the tip of the spring 122, and this steel ball is attached to the slide plate 118.
It is fitted into the curved recess 124 provided at 8 by the biasing force of the spring 12 and is stopped. Fixed mounting plate 1
00 and the fixed mold 110 are attached to each recess 1.
A spring 125 is interposed between 03 and 112, and both ends of the connecting body 107 inserted through the engagement hole 104 of the fixed mounting plate 100 and the engagement hole 113 of the fixed mold are fixed with 108 in the engagement holes 104 and 113. It is installed. Therefore, the space 109 formed with the spring 125 interposed between the spring 125
It will close slowly due to the urging force of. The movable mold 200 is fixed to a movable mounting plate (not shown), a spacer block (not shown), etc., and a cavity 201 and a core metal receiving groove 202 are formed on the surface thereof. Pin 2 on the side
03 and a spring 204 that applies an outward biasing force to the pin 203. Furthermore, the movable mold is provided with a slide plate 205 (the mechanism of the slide plate 205 is similar to that of the fixed mold 1).
(This is the same as the slide plate 118 provided in 10). 206 is a tapered plate surface provided on the slide plate 205 (however, the slide plate 118
and the length of the slide plate 205 have a relationship of 118<205).

Core metal 2 to be fitted into core metal receiving grooves 115, 202
20 has an engaging body 221 and an engaging body 2 therein.
21 (the surface of the engaging body 221 is formed into a curved concave shape in order to abut the curved convex portion at the tip of the contact portion 2A of the pin terminal 2) is provided with a spring 222 that applies a biasing force.

Moreover, both molds 110 and 2 into which the core metal 220 is fitted
The core metal receiving grooves 115 and 202 of No. 00 are larger than the core metal 220, and the core metal 220 is movable within the core metal receiving grooves 115 and 202.
Further, the core metal 220 is attached to the movable mold 200 by a sliding mechanism, as shown in FIG. 3A.
This slide mechanism includes an engagement recess 223 at the bottom of the core bar 220 and a stepped hole 2 provided in the movable mold 200.
10 by a locking protrusion 225 screwed by a screw 224. 207 is a cam receiver into which the cam 105 of the fixed mold 110 is inserted, 208 is a runner, 209 is a gate, and 230 is an ejector pin, each of which has the structure described in the prior art and operates.

In the above configuration, a method of forming a plug terminal will be explained.

First, the pin terminal 2 is inserted into the terminal position of the cavity 201 of the movable mold 200.

Second, connect a predetermined number of pin terminals to the cavity 2.
01, the movable mold 200 starts to rise to the position of the fixed mold 110 by the driving means, and the fixed mounting plate 100 and the fixed mold 110, which apply downward biasing force to the fixed mold 110, The mold is clamped against the spring 125 interposed between the two. At this time, the movement of the movable mold 200 rises against the biasing force due to the intervention of the spring 125, so that its rising speed becomes slow.

Thirdly, as shown in FIG.
continues to rise against the biasing force of the spring 125, the spring 125 is crushed between the engagement recesses 103 and 112 of the fixed mounting plate 100 and the fixed mold 110, and the fixed mounting plate 100 and the fixed mold 110 are brought into contact with each other. come into contact with Before this contact, the tapered part 106 of the cam 105 provided on the fixed mounting plate 100 is connected to the fixed mold 1.
The tapered portion 119 of the slide plate 118 of No. 10 contacts the slide plate 205 of the movable mold 200, and the slide portions 118, 205 move along the taper angle.
move. As a result, the slide plate 118,2
05 moves the core bar 220 toward the pin terminal 2 side.
However, due to the action of the pins 116 and 203 via the springs 117 and 204 provided in the core metal receiving groove 202 that apply a biasing force in one direction, the core metal
20 moves. Further, the tip of the pin terminal 2 is elastically connected to the cavities 114, 20 by the engaging body 221 via the spring 222 provided in the core metal 220.
1 in place.

After the fourth mold clamping, plastic resin for forming the insulating holder 3a and the insulating coating 4 on the pin terminal 2 is injected and a molding process is performed.

Fifth, when opening the clamped mold,
The movable mold 200 is lowered, and the fixed mounting plate 1 is first lowered.
The fixed mold 110 and the fixed mounting plate 100 are separated by the biasing force of the spring 125 interposed in the fixed mold 110. As the fixed mold 110 descends, the pressing force applied to the slide plate 118 of the fixed mold 110 and the slide plate 205 of the movable mold 200 along the taper of the cam 105 is released, and as a result, the spring 117 , 204 causes the pins 116, 203 to push the core bar 220 outward, and the holding state of the pin terminal 2 by the engaging body 221 due to the bias force of the spring 222 inside the core bar 220 is released.

As described above, the present invention allows the core metal holding the pin terminal to slide outward from the mold using the push pins of the mold when the mold is opened, and to slide toward the cavity side by the engagement of the cam and the slide plate during molding. , and the engagement between the cam and the slide plate is elastically engaged by a spring provided between the fixed mounting plate and the fixed mold.Furthermore, in order to engage elastically, the cam and the slide plate are engaged directly with the core metal that holds the pin terminal. Since no force is applied during mold clamping, the specified spacing and angle of each terminal can be maintained until molding.
In addition, since springs are installed in the fixed mounting plate and the fixed mold, the pressure and speed during mold clamping will change in the direction of decrease, which will prevent damage to the mold core metal due to mold clamping.
Wear is reduced, and since the pin terminal is held elastically by the spring installed in the core metal and the spring installed in the mold to hold the pin terminal between the core metal and the cavity, wear of the cavity part due to holding the pin terminal is reduced. decreases.

〔Effect of the invention〕

As explained above, according to the injection mold according to the present invention, when the mold is clamped by providing an elastic mechanism, the clamping speed and pressure against the pin terminal are changed, so that the core metal etc. The insulating holder and the insulating coating can be formed accurately with respect to the pin terminal while maintaining a predetermined interval and angle without causing any wear.

[Brief explanation of drawings]

Figure 1A is a front sectional view showing the structure of an injection mold according to the present invention, Figure 1B is a front sectional view of Figure 1A when the mold is clamped, and Figure 2 is a movable mold according to the present invention. A plan view of the mold, FIG. 3A is an explanatory diagram of the locking mechanism of the core bar and movable mold according to the present invention, FIG. 3B is an explanatory diagram of the stopping mechanism of the mold and slide plate according to the present invention, and FIG. Figures A and B are explanatory diagrams of a conventional injection mold, Figure 5 A is an explanatory diagram of a pin terminal, Figure 5 B is an explanatory diagram of a plug terminal, and Figure 5 C is an explanatory diagram of a plug after molding. It is a diagram. Explanation of symbols, 2...Pin terminal, 100...Fixed mounting plate, 105...Cam, 110...Fixed mold,
114,201...Cavity, 116...Pin, 117...Spring, 118,205...
Slide plate, 125... Spring, 200...
Movable mold, 220...core bar, 221...engaging body,
222...Spring.

Claims (1)

[Scope of Claims] 1 A pair of pin terminals are held in a predetermined position by a core metal in a cavity formed by clamping a fixed mold and a movable mold, and an insulating resin is injected into the cavity. Therefore, in an injection mold for molding a plug terminal, the core bar is slid in the cavity direction by a cam mechanism operated by the movement of the movable mold in the mold closing direction, and the slide holds the pin terminal. means, first buffering means that uses elastic force to reduce the impact on the pin terminal due to the sliding of the core metal, and fixed mounting means that supports the fixed mold on a side opposite to the movable mold. , a second buffer means disposed between the fixed mold and the fixed mounting means, which uses elastic force to cushion the impact when the movable mold and the fixed mold are clamped. An injection mold featuring: