JPS6011325A - Molding machine - Google Patents

Abstract

PURPOSE:To perform easily and precisely the changing or adjustment of the position of an ejector pin, by allowing a return pin to be separated longitudinally, and removing only the tip part of the return pin from the molding machine when the length is desired to be changed or adjusted. CONSTITUTION:In a state where a top and bottom forces 1, 2 are closed firmly, while the lower end of a return pin 21 abuts against the upper surface of the bottom force 2, if the lower end of an ejector pin 19 is retracted by a distance D from the ceiling surface of the cavity 3 of the top force 1, a projection will be formed on the molded item at that part when a resin is injected into the cavity 3. To obviate the formation of the projection, the lower surface of the ejector pin 19 should be flush with the ceiling surface of the cavity 3 of the top mold 1. In this case, for example, a spacer 35 with a thickness (t) equal to the depth D is removed from the return pin 21, and therefore an adjuster block 32 is secured to the tip of the bin main body 31. Thus the return pin 21 can be suitably shortened.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a molding technology, particularly a technology for adjusting the position of an ejector pin in a transfer mold machine, and is applicable to, for example, forming a resin-sealed package in a semiconductor device. Regarding effective molding techniques.

[Background Art] Generally, when forming a resin-sealed package for a semiconductor device, a molding machine is used that heats a synthetic resin (hereinafter referred to as resin) and injects it into a mold for molding (Japanese Patent Laid-Open No. 51115184). Publication No.).

In such a molding machine, when releasing the pancage from the mold, the pancage, which is a molded product, is pushed by an ejector bin and ejected from the cavity.

In such a case, the ejector bin needs to be able to protrude freely into the cavity and, at the time of molding, be on the same plane as the cavity. In order to adjust the position of the ejector bin with respect to the cavity, it is conceivable to use a return pin to regulate the correlation between the ejector bin and the cavity.

When adjusting the relationship between the ejector bin and the cavity using the return pin, it is necessary to change the length of the return pin, but changing the length of the return pin is important for maintaining the operating rate of the molding machine and the quality of the molded product. From these points of view, it is desired that the method can be implemented easily and accurately.

[Object of the Invention] An object of the present invention is to provide a molding machine that can easily and accurately adjust the position of an ejector bin.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

In other words, by making the return pin splittable in the axial direction, it is necessary to remove only the tip of the return pin from the molding machine and disassemble and reassemble other components of the molding machine when adjusting the length. This makes it possible to adjust the length without having to do so.

[Example] FIG. 1 is a longitudinal cross-sectional view of a molding machine that is an example of the present invention, and FIG. 2 is an enlarged cross-sectional view of the main parts.

In this embodiment, the molding machine is equipped with an upper mold 1 and a lower mold 2, both molds 1.2 forming a plurality of cavities 3 when aligned. The upper mold 1 communicates with a pot accommodating a resin tablet, and this pot 4 communicates with a plurality of cavities 3 via a runner 5 and a gate 6.

The upper and lower molds 1.2 are equipped with heating means such as electric heaters (not shown).
The heating plate 7.8 has a built-in heating plate 7.8, and the heating plate 7.8 has a built-in heating plate 7.8.

Appropriate numbers of spacer blocks 9 and IO are fixed to the upper and lower surfaces of the upper and lower heating plates 7.8, respectively, and the spacer blocks 9.10 are connected to the plates 11 and 12 via clampers 13.14, respectively. ing. On board 11,
A plunger 15 directly connected to the ram (not shown) of the transfer cylinder is inserted, and this plunger 15 is inserted into the pot 4 to forcefully feed the resin in the pot to each cavity 3 via the runner 5. . The platen 18 is supported by a ram (not shown) of a mold opening/closing cylinder, and as the ram moves up and down, it approaches and separates from the platen 11 relative to the platen 11, thereby moving the upper mold 1 to the lower mold 2.
Open and close the door. A rod 16 protruding from a machine base or the like is inserted into the panel 12, and the rod 16 is configured to relatively push up a lower ejector pin holder, which will be described later.

Ejector bin holders 17.18 are provided above and below the upper and lower heating plates 7.8, and both holders 17.1
8, a plurality of ejector pins 19, 20 are arranged so as to correspond to each of the cavities 3, and a plurality of return pins 21, 22 are arranged so as to correspond to the contact surface of the other mold 2 or l. It has been inserted. The upper ejector pin 19 and the return pin 21 are held by a back plate 23 provided on the holder 17, and are constantly pushed downward by a spring pressing mechanism 25. The lower ejector bin 20 and the return pin 22 are held by a back plate 24 provided below the holder 18, and are always moved away from the cavity 3 by a spring 26 interposed between the holder 18 and the heating plate 8. energized. Lower bank plate 24
A stopper 28 is interposed between the bank plate 12 and the bank plate 12, and this stopper 28 regulates the amount of separation of the bank plate 24.

Return pins 21 and 2 are shown in detail in FIG.
2 has a split structure that can be freely attached and detached in the axial direction.

That is, in FIG. 2, return pins 21 and 2
2 includes a main body 31 and an adjuster block 32. The main body 31 is formed into an elongated circular rod shape with a head 33 at one end, and the head 33 has at least a pair of parallel surfaces 34 formed therein. The main body 31 is held by having the head 33 sandwiched between the holder 17 (or 18) and the bank plate 23 (or 24), and is prevented from rotating by engaging the parallel surface 34 with the back plate. The adjuster block 32 is formed into a short cylindrical shape with the same diameter as the main body 31, has its center coincident with the front end surface of the main body 31, has a spacer 35 sandwiched therebetween, and is tightened and fixed by a bolt 36.

Next, the action and method of use will be explained.

After molding, when the plate 12 is lowered from the state shown in FIG. 1, the space between the upper and lower molds 1.2 opens. Since the back plate 23 is always urged downward with respect to the heating plate 7 by the spring holding mechanism 25, the upper return pin 21 moves relatively downward in the upper mold 1 as the lower mold 2 descends. will be moved to

As the return pin 21 moves downward, the holder 17 is pushed down by the spring holding mechanism 25.
The ejector pin 19 is pushed down with respect to the upper mold 1 and protrudes from the ceiling surface of the cavity 3 of the upper mold 1. Due to this protruding action of the ejector pin 19, the molded product is pushed downward and released from the cavity 3.

When the platen 12 is lowered to a predetermined height, the holder 17 comes into contact with the heating platen 7, so that the relative downward movement of the return pin 21 and the ejector pin 19 with respect to the upper mold 1 is stopped.

When the board 12 is further lowered, the lower back plate 24
is pushed up relative to the rod 16.

At this time, since the lower return pin 22 is separated from the upper mold 1 , the back plate 24 and the holder 18 are pushed up by the rod 16 and moved toward the lower mold 2 . As a result, the ejector pin 20 is projected from the bottom surface of the cavity 3 of the lower mold 2, pushing up the molded product and releasing it from the cavity 3.

For example, as shown in FIG. 2, when the upper and lower molds 1.2 are in close contact, the lower end of the return pin 21 is connected to the lower mold 2.
If the lower end of the ejector pin 19 is recessed by a depth D than the ceiling surface of the cavity 3 of the upper mold 1 even though it is in contact with the upper surface, when resin is injected into the cavity 3, A protrusion formed by filling the depth D will be formed on the molded product. In order to avoid the formation of this protrusion, it is necessary to align the lower end surface of the ejector pin 19 with the ceiling surface of the cavity 3 of the upper mold l.

In such a case, in this embodiment, for example, the spacer 35 having a thickness t equal to the depth D is removed from the return pin 21, and the adjuster block 32 is attached to the tip of the pin body 31 with the bolt 36. Fixed. Thereby, the total length of the return pin 21 is adjusted to be shortened by the length corresponding to the depth D.

In this way, when the overall length of the return pin 21 is shortened, the holder 17 whose position is regulated by the pin 21 is displaced in the direction closer to the upper mold 1 by the shortened amount, so that the ejector pin 19 is The position relative to the cavity 3 is changed so as to fill the void. That is, since the lower end surface of the ejector pin 19 coincides with the ceiling surface of the cavity 3, formation of protrusions in the molded product due to this is avoided.

Note that, contrary to the above, the ejector pin 19 is inserted into the cavity 3.
If the return pin 21 protrudes inward, the total length of the return pin 21 is extended by increasing the number of spacers 35 to be sandwiched. If the length adjustment of the return pin 21 by increasing or decreasing or replacing the spacer 35 is insufficient, the adjuster block 32 may be replaced or cut, for example.

Furthermore, the position of the lower ejector pin 20 relative to the cavity 3 can also be adjusted by adjusting the length of the lower return bin 22 as described above.

Incidentally, when rotating the bolt 36 to attach or detach the adjuster block 32 from the main body 31, since the main body 31 is prevented from rotating at the parallel surface 34 of the head 33,
The main body 31 is prevented from rotating with respect to the bolt 36, and attachment/detachment operations are easily and reliably performed.

[Effect (1): By configuring the return pin in a split structure consisting of the main body and the adjuster block, only the adjuster block can be removed, making it easier to disassemble and reassemble other components of the molding machine. Adjustments can be made to change the length of the return pin without the need.

In other words, in order to remove and remove the entire return pin and adjust the total length of this pin, in order to remove and remove the return pin,
It is necessary to disassemble and reassemble all the holding mechanisms for the return pin and ejector bin in the forming machine, such as the holder and hack plate, which wastes a lot of time and also requires reassembly after adjusting the length of the return pin. Due to the accumulation of fluctuations in assembly errors during assembly, the accuracy of position adjustment of the ejector bin with respect to the cavity deteriorates.

Therefore, by omitting disassembly and reassembly, it is possible to shorten the work time for adjusting the position of the ejector bin and improve the operating rate of the molding machine.Moreover, since there is no accumulation of error fluctuations during assembly, position adjustment is possible. Accuracy can be improved.

(2) By screwing the adjuster block to the main body, the structure is simple and the operation is easy, and the adjuster block can be attached to and removed from the main body.

(3) By providing a parallel surface on the zero body to prevent rotation, the body can be prevented from rotating together with the rotation of the screw member, so the adjustment bolt can be attached and detached easily and reliably.

Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the Examples and can be modified in various ways without departing from the gist of the invention. Not even.

For example, the structure is not limited to tightening and fixing the adjuster block to the main body via bolts, but it is also possible to have a structure in which the adjuster block and the main body are directly screwed together. The structure may be such that the main body is detachably connected to the main body simply by fitting the concave and convex portions.

In addition to inserting a spacer between the adjuster block and the main body, it is also possible to prepare adjuster blocks of different lengths in multiple standards and select the adjuster block with the appropriate length according to the length adjustment dimension. , may be replaced.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to a transfer molding machine, which is the field of application that formed the background of the invention. It can also be applied to machines, injection molding machines, etc.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the main parts. ■... Upper mold, 2... Lower mold, 3... Cavity, 4... Bot, 5... Runner, 6... Gate,
7.8... Heating plate, 9.10... Spacer block, 11.12... Board, 13.14... Clamper, 1
5... Plunger, 16... Mouth/7 de, 17.18
...Ejector bin holder, 19.20...Ejector bin, 21.22...Return pin, 23.24
...Back plate, 25.26...Spring holding mechanism, 31...Return pin body, 32...Adjuster block, 33...Head, 34...Parallel surface, 35...Space , 36...volts. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a forming machine equipped with a turn pin for adjusting the position of the ejector bin relative to the cavity once, the return pin is removably connected to the main body with its axis aligned with the tip of the main body. A molding machine characterized by being equipped with an Adjuster Pro 7. 2. The molding machine according to claim 1, wherein the adjuster block is configured to be attached to and detached from the main body by screw means. 3. The molding machine according to claim 2, wherein the main body has a parallel surface for preventing rotation.