JPH0423618Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an injection drive device for rotationally driving a metering screw and pushing a pusher plate in an injection molding machine.

Prior Art The injection drive device 1 in an injection molding machine is conventionally
As shown in the figure, a front plate 2 and a rear plate 3 are connected by a tie bar (also referred to as a tie rod) 4, and a pusher rod 5 is inserted between the two plates.
It is equipped so that it can be moved back and forth. A screw sleeve 6 having a pulley 7 for driving a metering screw on the front surface is mounted on the pusher plate 5 via a bearing 8, and a ball nut 9 is fixed on the rear surface. The rear plate 3 has a ball screw 10 for pushing the pusher plate.
is mounted on a shaft and driven in a fixed position by an injection pulley 11 fixed to the rear end. The front part of this ball screw 10 is screwed into the aforementioned boat nut 9, so that the pusher plate 5 moves back and forth as the ball screw rotates. A metering screw 12, indicated by a chain line, passes through the front plate 2 and has its base fixed to the screw sleeve 6. The metering screw 12, the screw sleeve 6, the ball nut 9, and the ball screw 10 are arranged coaxially.

In such a structure, the ball screw 10 driven and rotated at a fixed position necessarily requires a predetermined length to allow movement of the ball nut 9 corresponding to the injection operation stroke of the metering screw. A drawback was that the overall length of the injection drive device was increased in order to avoid interference such as collision with the rear end.

Problems to be Solved by the Invention The objective of this invention is to provide an injection drive device that has a small overall length and is compact.

Means to solve the problem: The screw sleeve for the measuring screw mounted on the pusher plate and the ball screw for pushing the pusher plate are arranged coaxially, and the front of the ball screw is inserted into the insertion hole at the rear of the screw sleeve. The structure is such that the parts can be inserted.

Function The insertion hole provided at the rear of the screw sleeve is
When the pusher plate is retracted, it accommodates the front part of the ball screw, reducing the distance between the front plate and the rear plate in an injection drive having the same injection stroke.

Embodiment In FIG. 1, an injection drive device 1 of an injection molding machine is shown.
As in the case of the conventional example, the front plate 2,
The rear plates 3 are connected by a tie bar 4, and a pusher plate 5 is attached to the tie bar 4 so as to be movable back and forth. On pusher plate 5,
A screw sleeve 6 is mounted on the front via a bearing 8, etc., and a screw sleeve 6 is mounted on the front of the sleeve 6.
The proximal end of the metering screw 12 is fixed, and a pulley 7 for driving the metering screw is also fixed, and an axial insertion hole 13 is formed in the rear portion to open rearward. pusher plate 5
A ball nut 9 is fixed to the rear surface of the bolt 9, and an injection ball screw 10, which is mounted on the rear plate 3, is screwed into the ball nut 9. The ball screw 10 is provided with an injection pulley 11 at its rear end and is driven and rotated by an injection drive motor (not shown). The measuring screw 12, the screw sleeve 6, the ball nut 9, the ball screw 10, and the insertion hole 13 in the screw sleeve 6 are arranged coaxially, so that the rear part of the ball screw 10 can be fitted into the insertion hole 13.

In general, the injection drive device 1 is configured such that after a metering operation in which a metering screw 12 is rotated by a pulley 7, a ball screw 10 is driven and rotated by an injection pulley 11, a pusher plate 5 is moved forward, and the metered resin is released. is ejected. Then, as the ball screw 10 reverses, the pusher plate 5 moves backward, completing one cycle of the injection operation. At the position where the pusher plate 5 is closest to the rear plate 3 at the end of this cycle, the insertion hole 13 in the screw sleeve 6
The front part of the ball screw 10 is fitted into the spacer to avoid collision between the two.

Effect: The front part of the ball screw for pushing the pusher plate fits into the insertion hole provided at the rear of the screw sleeve, so the distance between the pusher plate 5 and the rear plate 3 can be shortened at the end of the injection drive cycle. , the entire injection drive device becomes compact.

Along with this, the tie bar can be shortened, resulting in cost reduction, and the axis line leading to the screw sleeve and metering screw is also shortened, increasing the rigidity of the entire injection drive device, eliminating twisting and twisting of each bearing part.

[Brief explanation of drawings]

FIG. 1 is a front view partially showing the main part in cross section, and FIG. 2 is a front view showing the main part in a conventional example partially in cross section. 1... Injection drive device, 2... Front plate, 3... Rear plate, 4... Tie bar, 5...
... Pusher plate, 6 ... Screw sleeve, 7 ... Pulley for driving metering screw, 8 ...
... Bearing, 9 ... Ball nut, 10 ... Ball screw, 11 ... Injection pulley, 12 ...
...Measuring screw, 13...Insertion hole.

Claims (1)

[Scope of utility model registration request] The screw sleeve for the measuring screw mounted on the pusher plate and the ball screw for pushing the pusher plate are arranged coaxially, and the front part of the ball screw can be inserted into the insertion hole at the rear of the screw sleeve. An injection drive device featuring: