JPH0742670Y2 - Plunger of transfer molding machine and transfer molding machine using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a plunger of a transfer molding apparatus and a transfer molding apparatus using the plunger.

(Prior Art) A conventional transfer molding apparatus is shown in FIG. This device is designed so that the resin 104 contained in the pot 102 provided in the lower mold 100 (which may be the upper mold) is pumped to the resin path in the mold 100 by the upward movement of the plunger 106. Has become.
The plunger 106 slides up and down in the cylindrical pot 102, and is connected to a piston rod that constitutes a drive unit that drives the plunger 106 up and down via a plunger holder 108. Although it is ideal that all of the resin 104 put in the pot 102 is surely sent to the resin passage, since resin 104 is usually a tablet, resin powder is generated at the time of supply. This resin powder enters the plunger 106 and the inner peripheral surface of the pot 102 at a slight interval, and the plunger 106 that moves up and down is worn. As this wear progresses, the plunger 106 must be replaced, so that the conventional plunger 106 can be replaced with the plunger holder 108.

(Problems to be Solved by the Invention) However, the above-mentioned plunger has the following problems.

The plunger 106 is a head part when moving up and down in the pot 102.
If the length of 110 is too short, it will cause a swinging phenomenon, resulting in poor straightness. Therefore, it is necessary to lengthen the head portion 110 of the plunger 106 to stabilize the movement of the plunger 106. However, if the head portion 110 is long, the head portion 1
There is a problem that sliding resistance increases due to friction between 10 and the inner wall of the pot 102. Further, if the contact area between the head part 110 and the inner wall surface of the pot 102 is large, there is a problem that it is difficult to remove the resin powder that has entered between the two.

Therefore, it is an object of the present invention to provide a plunger of a transfer molding apparatus having a good straight running stability, a small sliding resistance with respect to an inner wall surface of a pot, and an easy removal of resin powder, and a transfer molding apparatus using the plunger. .

(Means for Solving the Problems) In order to solve the above problems, the present invention has the following configuration.

That is, in a plugger of a transfer molding apparatus in which a head part slides in a pot provided in a molding die to pump resin into the mold, a portion of the outer peripheral surface of the head part excluding the tip. And a non-contact portion that does not come into contact with the inner wall surface of the pot.

Further, in order to secure straight running stability with a small sliding resistance in the plunger, a guide part whose outer peripheral surface is slidable with the inner wall surface of the pot may be provided between the head part and the base part. Further, a second non-contact portion that does not contact the inner wall surface of the pot may be formed on the outer peripheral surface of the guide portion.

(Operation) The operation will be described.

By forming the non-contact portion on the head portion, the sliding resistance between the head portion and the inner wall surface of the pot can be reduced, and the resin powder that has entered the non-contact portion can be easily discharged.

When the guide portion is provided, the length of the head portion and the guide portion can be shortened, and the sliding resistance between the inner wall of the pot can be reduced. Further, when the guide portion is provided with the second non-contact portion, the sliding resistance can be further reduced, and the resin powder which has entered the second non-contact portion can be easily discharged.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a front view of the two-part split type plunger of the first embodiment,
2 is a front view of the plunger body, FIG. 3 is a plan view of the plunger body, FIG. 4 is a left side view of FIG. 3, and FIG.
The right side view of FIG. 3 is shown in the drawing, the sectional view taken along the line AA of FIG. 2 is shown in FIG. 6, the sectional view taken along the line BB of FIG. 2 is shown in FIG. 7, and the plunger lock is shown in FIG. FIG. 9, a plan view of the plunger lock, FIG. 10 is a left side view of FIG. 9, and FIG. 11 is a right side view of FIG.

The plunger 10 of the first embodiment is integrally formed by connecting a plunger body 12 and a plunger lock 14 with a screw.

First, the plunger main body 12 will be described with reference to FIGS.

The plunger body 12 is made of a material having wear resistance, such as cemented carbide, zirconia, and silicon carbide ceramics, and is formed in a columnar shape.

The upper part of the main body 12 is formed into a large-diameter head portion 16, and the diameter of the outer peripheral surface of the head portion 16 slides inside a pot 20 (see FIG. 12) in a lower mold 18 provided in the transfer molding device. The diameter is (movable up and down) The length (thickness) of the head portion 16 is preferably made short (thin) in order to reduce the sliding resistance between the outer peripheral surface of the head portion 16 and the inner wall surface of the pot 20. A polishing groove 24 is formed in the tip surface 22 of the head portion 16 at a depth of about 0.01 mm.
The polishing groove 24 is a mark for confirming the set state when the plunger 10 is attached to the mold 18. Head part 16 Flat non-contact part 26 from the middle part of the outer peripheral surface to the base side opposite to the tip
... are formed at four locations. The non-contact portions 26 ... Are formed at equal intervals in the circumferential direction of the outer peripheral surface of the head portion 16 (see FIG. 7). The non-contact portion 26 ... Is not formed at the tip of the head portion 16. This is because the resin 28 in the pot 20 is pumped by the tip surface 22 of the head portion 16, and at least the tip of the head portion 16 is in sliding contact with the inner wall surface of the pot 20 over the entire outer circumference. In addition, 30 is a labyrinth packing, the head part
It is engraved over the entire circumference of 16.

Reference numeral 32 denotes a guide portion for preventing the plunger 10 from swinging, which is formed in the middle of the main body 12 so as to be separated from the head portion 16.
The guide portion 32 is also initially formed in a cylindrical shape capable of sliding contact with the inner wall surface of the pot 20, and then the second non-contact portion 34 ... Which does not contact the inner wall surface of the pot 20 is provided on the outer peripheral surface at four locations in the circumferential direction. They are formed at intervals (see FIG. 6). Second non-contact part 34 ...
Is formed over the entire length of the guide portion 32 in the length (thickness) direction. Therefore, only the four ridge line parts 36 ... Make sliding contact with the inner wall surface of the pot 20 at the guide part 32. The length (thickness) of the guide portion 32 is also short (thin) to reduce sliding resistance.
Better.

38 ... is a pin hole, and a plunger lock 14 described later
When one is screwed into the female screw hole 40, a pin (not shown) is inserted to secure the main body 12 and the plunger lock 14 from one outer wall surface to the other outer wall surface with the same axis line. ing.

The plunger body 12 is divided into two along the chain double-dashed line X in FIG. 2 and FIG. 3, the head portion 16 side is formed of a difficult-to-cut material such as cemented carbide, and the female screw hole 40 side is easy to cut. It may be formed from a different steel and brazed together for joining.

Next, the plunger lock 14 will be described with reference to FIGS.

The plunger lock 14 is made of, for example, steel, and has a male screw portion 42 that can be screwed into the female screw hole 40 of the main body 12 on the right end surface thereof. The male screw portion 42 is also provided with a pin hole 44, and the male screw portion 42 is screwed into the female screw hole 40 of the main body 12, and the pin hole 38 ...
When 44 becomes coaxial, the pins are fitted into the pin holes 38, ..., 44 to fix the body 12 and the plunger lock 14.

The left end portion of the plunger lock 14 is formed in the connecting portion 46 and can be connected to the plunger holder 48 (see FIG. 12). As a method of connecting to the plunger holder 48, it is preferable to use, for example, the plunger connection structure (Japanese Patent Application No. 1-86255) that the applicant of the present invention has previously devised and applied. Recesses 50 ... Which can be fitted with a ball joint (not shown) are formed.

The plunger body 12 and the plunger lock 14 configured as described above are screwed together to form the plunger 10 shown in FIG. FIG. 12 shows a state in which the plunger 10 is inserted into a pot 20 provided in a lower mold 18 (or an upper mold in some cases), and a connecting body 46 of the plunger lock 14 is attached to a plunger holder 48. .

Labyrinth packing 30 of head part 16 and non-contact part 26 ...
The outer peripheral surface except for the inner wall surface of the pot 20 and the second portion of the guide portion 32
Outer peripheral surface excluding the non-contact part 34 ... (Ridge line part 36 ...)
And are in sliding contact with the inner wall surface of the pot 20.

Therefore, when the plunger 10 pressure-feeds the resin 28 upward, the guide portion 32 can prevent the plunger 10 from swinging, and the area in sliding contact with the inner wall surface of the pot 20 can be reduced to the non-contact portion 26.
.. and sliding resistance can be reduced because the size can be made smaller than in the case where the second non-contact portion 34 ... Is not provided. Further, the resin powder that has entered between the plunger 10 and the inner wall surface of the pot 20 can be easily dropped downward from the non-contact portion 26 ... And the second non-contact portion 34. Solvable.

Next, the second embodiment will be described with reference to FIGS. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

FIG. 13 is a front view of the plunger of the second embodiment, FIG. 14 is a plan view of the plunger, and FIG. 15 is a left side view of FIG.
FIG. 16 shows a right side view of FIG.

The plunger 70 of the second embodiment is one in which the plunger body 12 and the plunger lock 14 of the first embodiment are integrally formed, and for example, is entirely formed of steel.

The head portion 16, the guide portion 32, and the connecting body 46 are all the same in shape as in the first embodiment. In the case of the plunger 10 of the first embodiment, only the plunger body 12 can be replaced, but in the case of the second embodiment, the entire plunger 70 is replaced.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the number of non-contact portions and second non-contact portions is limited to four, for example. It goes without saying that more modifications can be made without departing from the spirit of the invention.

(Effect of the Invention) By using the plunger of the transfer molding apparatus according to the present invention, the sliding resistance between the head portion and the inner wall surface of the pot can be reduced, and the resin powder can be easily discharged through the non-contact portion. be able to. Further, by providing the guide, the swing of the plunger can be prevented and the sliding resistance can be reduced even if the length of the head portion is shortened.
Further, providing the second non-contact portion in the guide portion brings about a remarkable effect that the sliding resistance can be further reduced.

[Brief description of drawings]

FIG. 1 is a front view of a two-division type plunger of the first embodiment, FIG. 2 is a front view of a plunger main body, FIG. 3 is a plan view of the plunger main body, FIG. 4 is a left side view of FIG. 5 is the third
FIG. 6 is a right side view of the drawing, FIG. 6 is a sectional view taken along the line AA of FIG.
The drawing is a sectional view taken along the line BB of FIG. 2, FIG. 8 is a front view of the plunger lock, and FIG. 9 is a plan view of the plunger lock.
Fig. 11 is a left side view of Fig. 9, Fig. 11 is a right side view of Fig. 10,
FIG. 12 is a sectional view showing the usage state of the plunger of the first embodiment, FIG. 13 is a front view of the plunger of the second embodiment, FIG. 14 is a plan view of the plunger, and FIG. 15 is the left side of FIG. FIG. 16 is a right side view of FIG. 14, and FIG. 17 is a sectional view showing a conventional plunger in use. 10 …… Plunger, 16 …… Head part, 18 …… Mold, 20…
… Pot, 26 …… non-contact part, 28 …… resin, 32 …… guide part, 34 …… second non-contact part.

Claims (6)

[Scope of utility model registration request] 1. A plunger of a transfer molding apparatus in which a head part slides in a pot provided in a molding die to pump resin into the mold, the tip being an outer peripheral surface of the head part. A non-contact portion that does not come into contact with the inner wall surface of the pot is formed in a portion other than the portion of FIG. 2. A plurality of the non-contact portions are formed at intervals in the circumferential direction of the head portion from the middle portion of the outer peripheral surface of the head portion toward the base portion of the plunger. Plunger for the transfer molding apparatus described. 3. The transfer molding apparatus according to claim 1, wherein a guide portion is provided between the head portion and the base portion, the guide portion having an outer peripheral surface slidable with the inner wall surface of the pot. Plunger. 4. The plunger of the transfer molding apparatus according to claim 3, wherein a second non-contact portion that does not contact the inner wall surface of the pot is formed on the outer peripheral surface of the guide portion. 5. A plurality of the second non-contact portions are formed at intervals in the circumferential direction of the guide portion from the tip end direction of the guide portion outer peripheral surface toward the base portion direction. Plunger for the transfer molding apparatus described. 6. A transfer molding device using the plunger according to claim 1, 2, 3, 4 or 5.