JPS6159213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to parts constituting components of push button switches, etc., and relates to an insert molding method in which a conductor member, so-called lead frame, punched out at a fixed pitch is used as a base and a resin molded body is added to the base. .

The intention is to introduce a small frame feed drive system to automate mold forming or continuous molding, and to make the molding machine more compact or the movable mold smaller.

FIG. 1 is a plan view showing a concrete example of such a lead frame and a completed insert mold for molding the frame with a resin mold. In the figure, 1 is a lead frame punched in the pattern shown, 2 is a component such as a switch that is formed by insert molding the frame and insulating resin is added, and 3 is a connecting frame part of the frame 1, which is a series of processing steps. After the diameter, it is excised. Further, 4 is a gate (gate for resin injection) during molding, and 5 is a pitch hole drilled in the connecting frame portion 3. This hole is formed when patterning the lead frame, but it is essential for adjusting the feeding position in each automatic molding or automatic assembly process using the frame as a base in subsequent steps.

Although the illustration shows an example of molding a drive rod (one component of a switch) of a push button switch, such continuous processing of lead frames is widely used not only in the field of manufacturing switches but also in the field of manufacturing relays, connectors, etc. However, in the past, when using a resin molding machine to obtain multiple molded bodies 2 at the same time in each single molding cycle (for example, six molded bodies were molded at the same time), one feed was required for each single cycle, which required a large feeding device. However, there was a drawback that it was difficult to downsize not only the molding machine but also the mold.

The aim of the invention is to eliminate the above-mentioned drawbacks. To achieve this purpose, the lead frame is fed by a predetermined length in each molding cycle in multiple divided feeds, and a sensor is provided to detect whether or not the lead frame is set at a predetermined position in the mold. This is what I presented.

FIG. 2 is a side view showing the main parts of the target insert molding machine, and FIG. 3 is an operation process diagram illustrating the molding process of the present invention. In the molding machine shown in FIG. 2, reference numeral 10 denotes a stationary die whose lower end surface forms a cavity, and numeral 11 denotes a movable die whose upper end surface forms a cavity, which pairs with the stationary side to form a molded body. 12 is an eject plate, 13 is an eject pin, 14 is a knob bar, these 12, 1
3 and 14 are parts from which the molded body is ejected after the mold is opened. 15 is a guide plate for setting the lead frame 1 to be processed; 16 is an air cylinder that supports and drives the plate 15; 17 is a cam attached to the guide plate 15; and 18 is attached to the movable mold 11. This is a feeding device for the lead frame 1 attached to the support base 20, and feeding is driven by an air cylinder. However, in order to facilitate continuous molding of the lead frame to be processed, control switches S ₁ , S ₃ , S ₄ and the like having the following configuration are provided. This is the third
This will be explained with reference to the explanatory diagram of the molding process shown in the figure.

Figure A in Figure 3 shows a state in which the movable mold 11 has descended and opened to the bottom dead center, and at this time the cam mounting switch S ₁
The frame feed device 18 is opened and the switch is
Cylinder 16 is activated by _S4 . At the same time, the guide plate 15 is moved upward by pushing up the dowel rod 14 (to the state shown in the figure). S ₄ in the figure shown in Fig. 3 is a switch S ₃ that holds the cylinder 16 in the illustrated state and is installed between the eject plate 12 and the movable mold in this state.
operates to start the feeding device 18.

FIG. 3C shows that frame feeding is carried out by the feeding device 18 in two or three divided feedings to obtain simultaneously molded bodies corresponding to a predetermined length of lead frames, for example, six lead frames. That is, the feed of the lead frame 1 in the direction of the arrow shown in the figure is carried out by a repeated operation in small intervals. When the feeding is completed, the feeding device 18 (not shown)
Upon receiving a signal from the controller, the holding state of the cylinder 16 is released (see figure 2), and as a result, the guide plate 15 descends and the lead frame 1 (or 3, see figure 1) is set in the guide groove of the movable cavity. be done. This state is the state shown in FIG. 3. Next, the mold is clamped for molding, and in the state shown in Figure 2, two sensors (switches) connected in series S5 attached to the guide plate ₁₅ detect whether or not the lead frame is set in the predetermined position in the cavity. However, if it is not set,
Since _S5 is not operating, mold clamping of the molding machine (see diagram) is not performed.

In FIG. 5E, the lead frame is set in the cavity of the mold 11 in step _S5 , and after confirmation, the mold is clamped and the subsequent molding process begins. The operation cycle of single molding is thus completed.

According to the present mold forming machine shown in the above embodiment, a large work can be performed with a small frame feed drive device, so that it is possible to downsize the mold. Furthermore, since the lead frame position detection function is provided before mold clamping, there is no mold clamping in an incomplete state between the lead frame and the mold, and damage to the mold can be prevented.
From this point of view, the industrial value of the present invention is great.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a lead frame, which is the target workpiece of the present invention, and a completed product obtained by molding the lead frame, and FIG. FIG. 3 is an explanatory diagram of the operation process of the molding machine shown in FIG. 2. In the figure, 1 is a lead frame, 2 is a molded body, 3 is a connecting frame 1, 5 is a pitch hole, 10 is a fixed side mold, 11 is a movable side mold, 12 is an eject plate, 14 is a knock bar, 15 is a guide plate of the lead frame 1, 16 is an air cylinder, 17 is a cam, 18 is a frame feeding device, 20 is a support for 18, _S3 is a switch attached to the lower eject plate 12 side of the mold 11, and S ₅ is guide plate 15
This is a sensor (switch) installed on the lead frame to detect the lead frame feed position.

Claims (1)

[Claims] 1. Conductor members as components such as switches are formed by punching a lead frame as a base and molding it, using molds on the fixed side and movable side, a guide plate for feeding the lead frame on the movable side mold side,
The lead frame is fed a predetermined length in each molding cycle by multiple divided feeds, and a sensor is provided to detect whether the lead frame is set at a predetermined position in the mold. A lead frame insert molding method characterized by: