JPH0620575Y2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an injection molding machine, and more particularly to an injection molding machine including a drive mechanism for moving an injection unit in the front-rear direction.

[Prior Art] The configuration of a conventional injection molding machine will be described with reference to FIGS. 2 and 3.

Reference numeral 1 in the drawing is a machine body. A mold 1a (only a fixed mold is shown in the drawing) and a slide base 2 are provided on the upper part of the machine body 1. The slide base 2 is different from the mold 1a. It is movable in the direction of approaching and separating (left-right direction in FIG. 2).

An injection nozzle 3 is provided on the slide base 2.
An injection unit 3 including a and a heating cylinder 3b is fixed, and a unit moving mechanism for moving the slide base 2 together with the injection unit 3 in the above-mentioned direction between the slide base 2 and the machine body 1. A
Is provided.

Then, the unit moving mechanism A moves the injection unit 3 toward the mold 1a, and the injection nozzle 3a is brought into contact with the mold 1a. After this nozzle touch, the injection nozzle 3a to the inside of the mold 1a. It is designed to inject molten resin into.

On the other hand, the unit moving mechanism A has the following configuration.

That is, the ball nut 4 is fixed to the front end of the slide base 2. The ball nut 4 is arranged with its axial direction along the moving direction of the slide base 2.

A long ball screw shaft 5 is screwed into the ball nut 4. On one end 5b side of the ball screw shaft 5,
A mounting shaft 5c is formed. A screw portion 5d is formed near the end of the mounting shaft 5c.

A sleeve 6 is attached to the outer periphery of the attachment shaft 5c. A sprocket 7 and an inner ring of a bearing 8 are attached to the outer circumference of the sleeve 6, respectively.

One end of a chain 9 is wound around the outer circumference of the sprocket 7. The other end of the chain 9 is wound around the outer circumference of a sprocket 11 fixed to the outer circumference of an output shaft 10a provided on the electric motor 10.

A fixed cylinder 12 is fitted onto the bearing 8.
The fixed cylinder 12 is fixed to the machine body 1 via a bracket 13.

Further, a nut 5e for preventing the mounting shaft 5c from coming out of the sleeve 6 is screwed into the threaded portion 5d.

According to the above conventional injection molding machine, the ball screw shaft 5 is rotated through the sprocket 11, the chain 9 and the sprocket 7 by starting the electric motor 10 and rotating the output shaft 10a thereof, and the ball screw shaft 5 is screwed. By moving the combined ball nut 4 in the front-rear direction, the injection unit 3 can be moved in the front-rear direction, and the nozzle touch and its release can be performed.

[Problems to be Solved by the Invention] However, in the above conventional injection molding machine, when the ball screw shaft 5 is rotated to move the injection unit 3 forward and backward, the ball screw shaft 5 is long. There is a problem that shaft run-out may occur, which may be a source of vibration and noise in the injection molding machine, and that the load of the ball screw shaft 5 may be repeatedly applied and the life of the ball screw shaft may be shortened due to metal fatigue. Since this problem remarkably occurs when the ball screw shaft 5 is rotated at a high speed,
The ball screw shaft 5 cannot be rotated at a high speed to shorten the moving time of the injection unit 3, and the efficiency of the injection molding work is hindered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an injection molding machine that can shorten the moving time of an injection unit.

[Means for Solving the Problems] The injection molding machine of the present invention includes a machine body, a slide base attached to the machine body and movable in the front-rear direction, and an injection unit attached to the slide base. A nut rotatably attached to the machine body and immovable in the axial direction relative to the machine body, and arranged along the movement direction of the slide base in the axial direction; And a screw shaft whose one end side is fixed to the slide base and is relatively movable in the axial direction with respect to the nut,
A drive means is provided which is attached to the machine body and rotationally drives the nut.

[Operation] When the nut is rotated by the drive means, the screw shaft screwed to the nut and the nut relatively move in the axial direction,
As a result, the injection unit is moved forward and backward together with the slide base, and the nozzle touch and its release are performed. In this case, since the nut screwed with the screw shaft is rotated, the occurrence of shaft runout of the screw shaft is suppressed, and the forward and backward movement of the injection unit is smoothly performed.

[Embodiment] An embodiment of the injection molding machine of the present invention will be described with reference to FIG.

The same components as those of the conventional injection molding machine will be designated by the same reference numerals and detailed description thereof will be omitted.

In the injection molding machine of this embodiment, the sleeve 16 is fitted around the ball nut 4 (nut), and the ball nut 4 and the sleeve 16 are integrally connected by means such as a bolt. A bearing 18 is fitted to the outer periphery of one end side (left side in FIG. 1) of the sleeve 16, and the bearing 18 is fitted and fixed inside a fixed cylinder 22 fixed to the machine body 1. As a result, the ball nut 4 is attached to the machine body 1 rotatably and immovably in the axial direction.

A driving means 30 for rotating the ball nut 4 is attached to the other end of the sleeve 16. The driving means 30 includes a cylindrical pulley 17 fixed to the outer circumference of the other end of the sleeve 16, an electric motor 10 having an output shaft 10a, a pulley 10b fixed to the outer circumference of the output shaft 10a, and The timing belt 23 is provided around the outer circumferences of the pulleys 17 and 10b.

Further, in the injection molding machine of the present embodiment, the fitting portion 5e is formed on one end 5a side of the ball screw shaft 5 (screw shaft), and the fitting portion 5e is formed in the through hole 2a formed in the slide base 2. It has been inserted. A nut 5g is screwed into the threaded portion 5f formed at the end of the fitting portion 5e, and the one end 5a side of the ball screw shaft 5 is fixed to the slide base 2 by the nut 5g. 5 are arranged along the moving direction of the slide base 2. In the injection molding machine of this embodiment, the ball screw shaft 5 is movable along with the slide base 2 in the axial direction with respect to the machine body 1.

Next, the operation of the injection molding machine of this embodiment having the above configuration will be described.

First, when the electric motor 10 is activated to rotate the output shaft 10a, the ball nut 4 is rotated via the driving means 30. In the injection molding machine of this embodiment, the ball nut 4
Is attached to the machine body 1 through the sleeve 16, the bearing 18, and the fixed cylinder 22 so as to be immovable in the axial direction, and the ball screw shaft 5 is movable in the axial direction with respect to the machine body. When 4 rotates in the forward and reverse directions, the ball screw shaft 5 moves back and forth in the axial direction. Then, the slide base 2 fixed to the ball screw shaft 5 and the injection unit 3 mounted on the slide base 2 move in the front-rear direction.

According to the injection molding machine of this embodiment, the injection unit 3 is moved by rotating the ball nut 4, and it is not necessary to rotate the ball screw shaft 5 as in the conventional case. Does not occur.

Therefore, even when the rotation speed of the ball nut 4 is increased and the moving speed of the injection unit 3 is increased, it is possible to prevent noise and vibration from occurring in the injection molding machine.

This also has the advantage that the moving time of the injection unit 3 can be shortened and the efficiency of the injection molding operation can be promoted.

In the above embodiment, as the power transmission means between the output shaft 10a of the electric motor 10 and the ball nut 4,
Although the pulleys 10b and 17 and the timing belt 23 are used, a power transmission means such as a chain or a gear may be used.

Further, although the ball nut 4 and the ball screw shaft 5 are used in the above-described embodiments, a normal screw shaft and nut may be used.

[Advantages of the Invention] The injection molding machine of the present invention includes a machine body, a slide base mounted on the machine body and movable in the front-rear direction, an injection unit mounted on the slide base, and the machine. A nut rotatably mounted on the body and immovable relative to the machine body in the axial direction, and arranged axially along the moving direction of the slide base; A screw shaft, one end side of which is fixed to the slide base and is relatively movable in the axial direction with respect to the nut,
Since the drive unit is attached to the machine body and rotationally drives the nut, the screw shaft is increased even when the rotational speed of the nut is increased and the moving speed of the injection unit is increased. It is possible to prevent noise and vibration from occurring in the injection molding machine without causing shaft runout. Therefore, there is an effect that the injection unit can be moved at a high speed, the moving time can be shortened, and the efficiency of the injection molding operation can be promoted.
The nut is attached to the machine body, which is a fixed system, so that it can be rotated and cannot move in the axial direction relative to the machine body.
Moreover, since the machine body is provided with the drive means for rotationally driving the nut, it is easy to supply energy to the drive means,
Wiring of electric wires or supply of compressed air or pressure oil is easy. Further, as described above, the machine body side, which is the fixed system, is provided with the rotating member such as the nut and the drive means, which also reduce the occurrence of vibrations. And noise can be prevented.

[Brief description of drawings]

FIG. 1 shows an embodiment of an injection molding machine according to the present invention. FIG. 1 shows a cross-sectional view of the injection molding machine. FIG. 2 shows a conventional injection molding machine. Figure is III of Figure 2
FIG. 3 is a cross-sectional view of the injection molding machine taken along the line III. 1 ... Machine body, 2 ... Slide base, 3 ... Injection unit, 4 ... Ball nut (nut), 5 ... Ball screw shaft
(Screw shaft), 30 ... Driving means.

Claims (1)

[Scope of utility model registration request] 1. A machine body, a slide base attached to the machine body and movable in the front-rear direction, an injection unit attached to the slide base, and a machine body rotatable and rotatable with respect to the machine body. Is attached so as not to move relative to the axial direction, and
A nut arranged with its axial direction along the moving direction of the slide base, and screwed to the nut, and one end side of which is fixed to the slide base, and is relatively movable in the axial direction with respect to the nut. Injection-molding machine, comprising: a threaded shaft that is mounted on the machine body; and a drive unit that is mounted on the machine body and that rotationally drives the nut.