JPS61185423A - Injection molding machine - Google Patents

Abstract

PURPOSE:To permit a rubber or plastic to be injected into a cavity directly from an injection nozzle through a short distance without using a runner block even if the position of the gate for a molded item is out of the center of a mold, by allowing an injection apparatus to be moved in a plane normal to the axis of the nozzle. CONSTITUTION:A clamping apparatus 12 for clamping and fixing a mold at its lower part is provided and an injection apparatus 13 is positioned over it. The injection apparatus 13 is stood via an upper platen 15 on a slide reciprocating mechanism 20 and can be reciprocated in directions shown by arrows (A, B). If the intended item is sheetlike or profiled, the gate is often positioned at the end of the cavity, but even in that case, injection molding can be effected with the injection nozzle 37 itself moved without using a runner block.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an injection molding machine, and more particularly to a molding machine for rubber injection or plastic injection.

[Conventional technology]

In conventional injection molding machines of this type, the injection nozzle was always pressed along the axis of the mold clamping device to inject rubber or plastic.

That is, as shown in FIG. 10, the injection nozzle 1 reciprocates along the axis 3 of the mold clamping device 2 as shown by arrows A and B, and if the injection molding machine is vertical, it , corresponded to the center points of the molds 4 and 5.

[Problem that the invention seeks to solve]

In FIG. 10, depending on the molded product (product), it may be necessary to bring the gate 6 to the end of the product, and therefore a runner 7 is required to connect the nozzle in the center and the gate 6 at this end. Therefore, a runner block 8 with a runner 7 is required, and for rubber molding it must be a cold runner block that is cooled by a cooling device 9, and for plastic molding it must be a hot runner block that is heated by a heating device. , the mold and the cooling (heating) device become complicated and the cost increases.

Furthermore, a pressure loss occurs due to the passage through the runner 7, and it is necessary to increase the plunger injection pressure of the inflowing rubber or plastic. Depending on the size and shape of the molded article (product), the pressure at the gate 6 may become insufficient due to the pressure loss due to the resistance of the runner 7, and injection molding may not be possible.

Also, if you omit the runner block mentioned above and try to take one large-formed product (large product), the
The eccentric cavity 10 must be arranged as shown in the figure. In other words, since the gate 6 is placed in the center of the upper and lower molds 4°5, the cavities lO are unevenly distributed, and therefore,
As shown in FIG. 12 (at a position away from the axis 11 of the mold 4.5, pressure is applied during injection in the direction of the arrow, resulting in uneven crispness of the molded product. In other words, at a position away from the axis 11 The wall thickness of the paris is large, and the wall thickness becomes small near the axis 11, resulting in non-uniformity and ruining the product value.

Therefore, for injection of large molded products, in order to balance the pressure, it was unavoidable to use two cavities as shown in FIG. 13. As a result, the mold 4.5 has become larger, and the pressing hot plate or gouly plate has also become larger, resulting in higher costs.

An object of the present invention is to solve all of these conventional problems.

[Means for solving problems]

An injection molding machine according to the present invention is an injection molding machine equipped with an injection device having a plunger and an injection nozzle for injecting rubber or plastic, and a mold clamping device for clamping and fixing a mold. The device is movable within a plane orthogonal to the axis of the nozzle and is provided opposite to the mold clamping device.

[For production]

Even if the position of the gate of the molded article (product) is off from the center of the mold, rubber or plastic can be injected into the cavity directly from the injection nozzle at the shortest distance without using a runner block. In other words, the nozzle itself of the injection device is moved within a plane perpendicular to the nozzle axis to accommodate the unevenly distributed gates.

〔Example〕

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

1, 2, and 3, a vertical injection molding machine is illustrated, and a mold clamping device 1 that clamps and fixes a molding die downward is shown.
2, has an injection device 13 above it, and has a control device 14 on the side.

The mold clamping device 12 has an upper plantain 15, a lower plantain 16, and a plurality of tie rods 17 that vertically connect these, and has a clamp cylinder 18 at a lower position.

As shown in the simplified plan view of FIG. 6, an elongated hole 19 is provided through the upper brush ten 15.

The injection device 13 is installed upright on the upper plantain 15 via a slide reciprocating mechanism 20, and is shown by arrow A in FIGS. 3 and 6.
It is possible to reciprocate in the B direction, thus in the direction perpendicular to the paper plane of FIGS. 1 and 2.

Specifically, the guide groove 21 is formed by the sliding plate piece 24 and the inverted-shaped piece 25 fixed to the upper surface of the upper plantain 15. The guide grooves 21, 21 have long holes 19 arranged in parallel along the linear sides, and are opposed to each other. The convex portion 22 of the slide member 23 fits into this guide groove 21.

The slide reciprocating mechanism 20 has the guide groove 21.
21 and slide members 23 and 23.

A column 26 is erected on this slide member 23', and a cylinder mounting plate 27 is fixed to the upper end of this column 26.

A fluid cylinder 28 is fixed to the center of the cylinder mounting plate 27 in an inverted manner, and the piston rod 2 of the fluid cylinder 28
The lower end of the guide plate 9 is connected to a guide plate 30 that is vertically movably guided by the support columns 26 .

Reference numeral 31 designates an injection cylinder, which includes a cylinder tube 34 which is attached in a hanging manner to a slide rad 33 that is vertically movably guided by struts 26, and a cylinder chamber 35 at the axis of this cylinder tube 34. The plunger 36 is inserted from the plunger 36.

The upper end of the plunger 36 is fixed to the guide plate 30,
Alternatively, it is directly connected to the piston rod 29. The lower end of the injection cylinder 31 can be loosely fitted into the long hole 19, and an injection nozzle 37 is fixed to the lower end. Also, in the middle of the cylinder tube 34, from the lateral direction (horizontal direction),
A molding material supply screw device 38 is attached.

This screw device 38 is composed of a screw outer cylinder 39, a screw 40 rotatably housed in the screw outer cylinder 39, a hopper 41 for dropping the molding material onto the base end side of the screw 40, and a motor 42 for driving the screw. 43 is a check valve for preventing backflow.

Further, 44 is the cylinder mounting plate 27 and the slide head 33.
By the expansion and contraction of this fluid cylinder 44, the rad 33, cylinder tube 34, screw device 38, and injection nozzle 37 move as one in the direction of arrow F□, that is, in the axial direction□. , mold 4
It is press-contacted to the sprue opening 46 which opens in the upper surface of 5 so that it can be press-contacted and separated. In FIG. 1, a locate ring 47 is fitted in the vicinity of this sprue opening [1 part 46]. Sprue 4
8 communicates with a molded product cavity (not shown).

By the way, in order to move the injection device 13 in the directions of arrows A and B, that is, in a plane perpendicular to the axis of the injection nozzle 37, various mechanisms such as a fluid pressure cylinder or a screw shaft can be freely selected. However, in FIGS. 2 and 3, it is moved by a hydraulic cylinder 49. FIG. 6 shows how the cylinder tube 34 moves horizontally along the elongated hole 19 of the upper brush 15.

Next, the embodiment shown in FIG. 4 is specifically illustrated to make the present invention easier to understand compared to the conventional example shown in FIG. 10. That is, the gate 51 is located near the right end of the cavity 50.
In the case of a molded product where it is necessary to provide the upper mold 45
A sprue 48 is formed directly above this gate 51, and the injection nozzle 37 is pressed against the opening of this sprue 48. Therefore, a runner block 8 having a complicatedly curved runner 7 as shown in FIG. 1θ is not used.

Therefore, the opening of the sprue 48 is shifted to the right from the center of the mold 45, and by moving the injection nozzle 37, injection cylinder 31, etc. in the direction of arrow B by the amount of this shift,
The injection nozzle 37 corresponds to the sprue opening. Of course,
A long hole 19 is formed in the upper brush platen 15 to allow movement of the injection cylinder 3 in the directions of arrows A and B.

5A and 5B show the case where the cavity 50 is arranged approximately in the center of the mold 45 in this way, and the gate 51
is eccentric to the right from the mold center point 52 when viewed in plan.

Since the injection nozzle 37 is movable in the directions of arrows A and B as described above, even if the openings of the gate 51 and the sprue 48 are eccentric, the injection nozzle 37 can perform press-contact injection. As is clear from comparing FIG. 5A with FIG. 11 of the conventional example, the force that tends to separate the upper and lower molds due to the pressure inside the cavity 50 is applied almost equally around the mold center 52, so the molding The texture of the product will be uniform all around.

7 and 8 show another embodiment of the invention.

Generally, the upper bluff 15 receives a large external force during mold clamping, and therefore requires sufficient rigidity and strength. However, if the elongated hole 19 is provided as in the above-mentioned embodiment, it is expected that sufficient rigidity and strength may not be obtained.

Therefore, one circular hole 54 whose center is at the center point 53 of the upper plantain 15 is penetrated, and around this circular hole 54, the centers are located at different distances Ra, Rb, Rc, and Rd from the center point 53, respectively. Circular holes 55a, 55b, 55c with the same diameter
, forming 55d. Circular holes 54.55a, 55b・
... are mutually independent, therefore (not shown)
A reinforcing member can be freely attached to the upper bran 15. The inner diameters of the circular holes 54, 55a, 55b, etc. may be set slightly larger than the outer diameter of the insertion site of the cylinder tube 34. Note that the circular holes may be used as elongated holes as long as the holes are not continuous with each other. It's good as well.

Further, as shown in FIG. 8, the slide reciprocating mechanism 20a supports the injection device 13 so that the injection device 13 can be moved in all directions (that is, front, rear, left, and right directions) within a plane perpendicular to the axis of the injection nozzle 37. It is attached to the upper braften 15.

Specifically, the guide groove 21 and slide member 23 already explained in FIG.
It is possible to move not only in the directions of arrows A and B in the figure but also in the directions of arrows C and D.

Next, as shown in FIG. 9, in another embodiment, a mold clamping device 12 is provided on the left side of a base 56, and an injection device 13 is provided on the right side, showing an example of a horizontal injection molding machine.

The blank 57 of the mold clamping device 12 has a horizontal long hole 19.
a is formed, and the entire injection device 13 is mounted on the right upper surface of the base 56 so as to be movable in the front and back direction (see arrow) via a slide reciprocating mechanism.

Reference numeral 31 indicates an injection cylinder, and a nozzle is attached to the tip thereof.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and is of course free to change the design within the scope of not forming a film. For example, in a horizontal shape as shown in FIG. The injection device 13 shown in FIG. 9 is attached to the base 56 via a slide reciprocating mechanism movable in the direction, and the plantain 57 has circular holes 54, 55a as shown in FIG.
It is also preferable to use one in which a plurality of holes 55b... are provided through the hole. The present invention can be used for injection molding of both rubber and plastic.

〔effect〕

In the present invention, since the injection device 13 is provided movably within a plane perpendicular to the axis of the injection nozzle 37, the above-mentioned conventional problems can be solved and the following significant effects can be achieved. do.

(a) When the molded product is a sheet-like or irregularly shaped product, it is often necessary to place the gate at the end of the cavity.In such cases, the injection nozzle 37 itself can be used without using a launch block. It can be moved and injection molded.

(b) The launch block must be a hot runner (in the case of plastic molding) or a cold runner (in the case of rubber molding), but since such a runner block can be omitted, manufacturing costs can be reduced.

(c) Moreover, the runner part is not required, and the molding material is sent to the gate via the shortest distance from the injection nozzle. Therefore, pressure loss is reduced, and products that could not be injection molded in the past can be molded at high pressure.

(D) (As is clear from comparing FIGS. 5A and 5B with the conventional FIG. 11), the cavity can be placed near the center of the mold, and the periphery of the molded product can be made uniform.

(E) (As is clear from comparing Fig. 5A with the conventional Fig. 13) In conventional large-sized product molding, two cavities were unavoidably used for pressure balance, but with the present invention, even one cavity can be formed. If it is placed in the center of the mold, the pressure can be balanced, so the mold can be made smaller and the press hot plate (or gou plate) can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a partially sectional enlarged front view showing an embodiment of the present invention;
Figure 2 is an overall front view showing a modified example, Figure 3 is a side view of the same,
Fig. 4 is a sectional view of main parts showing another embodiment, Fig. 5A and Fig. 5
Figure B is a simplified plan view of the mold showing the arrangement of cavities and gates, Figure 6 is a simplified plan view explaining the arrangement of long holes, Figure 7 is a simplified plan view of a plantain showing another embodiment, 81 is an enlarged partial view of the main part corresponding to FIG. 7, and FIG. 9 is a perspective view showing still another embodiment in a horizontal configuration. Fig. 10 is a sectional view of main parts showing the conventional example, Fig. 11 is a simplified plan view for explaining the problems of the conventional example, and Fig. 12 is a sectional view of the main part of the conventional example.
The sectional view (12-12) in the figure and FIG. 13 are simplified plan views for explaining the problems of the conventional technology. 12... Mold clamping device, 13... Injection device, 36...
Plunger, 37... Injection nozzle, 45... Mold. Agent Patent Attorney Takeshi Nakatani Figure 2
Figure 3 Figure 4 Figure 5A Figure 58 Figure 6 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. In an injection molding machine equipped with an injection device having a plunger and an injection nozzle for injecting rubber or plastic, and a mold clamping device for tightening and fixing a mold, the injection device An injection molding machine, characterized in that it is movable within a plane perpendicular to the axis of the nozzle and is provided opposite to the mold clamping device.