JPH0349921A - Injection device for molding press - Google Patents

Abstract

PURPOSE:To control the position and speed of a piston easily and with high accuracy by carrying out piston driving of an injection cylinder by means of a servo mechanism. CONSTITUTION:When a servo motor 5 is operated, its rotation force is converted into thrust for driving a piston 2 through a driving force converting mechanism of a belt 6, a speed reducer 7, a coupling 8 and a ball screw 9, and the piston 2 is driven by said thrust to inject resin placed in an injection cylinder 1 out of an injection opening la and carry out resin molding. As the driving of piston is carried out by a servo mechanism as above-mentioned, the position and speed of the piston can be controlled easily and with high accuracy. As the means of providing injection pressure is not hydraulic but motorized, a hydraulic unit and the like are not required to make the whole of a device small and inexpensive.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an injection device for a molding machine.

[Conventional technology]

FIG. 3 is a front view showing an injection device of a conventional molding machine, and FIG. 4 is a partial top view taken from line 1--2 in FIG. In the figure, (1) is an injection cylinder, which has an injection port (1a) at a part of its opening. (2) is the injection cylinder (1
) and is connected to the piston rod (2a). (3) is a fixed fulcrum (3a
) is a lever that swings around the piston rod (2a).
A movable fulcrum (4) provided at is slidably engaged. Note that the lever f3) is a hydraulic cylinder (not shown).
It is designed to be driven by

Next, the operation will be explained.

A lever (
3) The movable fulcrum (4) is driven by the lever principle, and the piston rod (2a) and piston (2) are reciprocated to move the resin placed in the injection cylinder (1) into the injection port (1).
a) Extrusion and resin molding.

[Problem to be solved by the invention]

Since the injection device of a conventional molding machine is configured as described above, it requires a hydraulic unit as a drive source, and various sensors are used to control the position and speed of the piston (2), which is difficult to do. There were many problems.

This invention was made to solve the above-mentioned problems, and its purpose is to provide an injection device for a molding machine that can be made smaller and easier to operate and adjust by driving the piston using a servo mechanism. do.

[Means to solve the problem]

In the injection device for a molding machine according to the present invention, a piston of an injection cylinder is driven by a servo mechanism.

[Effect]

The piston-driven servo mode according to the present invention can easily and accurately control the position and speed of the piston.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. Figure 1 is a front view, Figure 2 is the line from Figure 1 -
It is a partial top view seen from (2), and the same or corresponding parts as the conventional device are given the same reference numerals and explanations are omitted. In the figure, (5) is a servo mode for driving the piston (2), and the rotational force of this servo mode (5) is transmitted through the belt (6), the reducer (7), the coupling (8), and the ball. The driving force conversion mechanism of the screw (9) converts the driving force into thrust, which drives the piston.

Next, the operation will be explained.

When the servo mode (5) is operated, its rotational force is transferred to the piston (2) via the driving force conversion mechanism of the belt (6), deceleration m (71), coupling (8), and ball screw (9).
is converted into thrust that moves the piston (
2) moves, the resin placed in the injection cylinder (1) is injected from the injection port (1a), and resin molding is performed.

〔Effect of the invention〕

As described above, according to the present invention, the piston is driven by a single electric servo system, which makes it easy to control the position and speed of the piston, which was extremely difficult with the conventional hydraulic drive system. It can be performed with high precision, and since this device uses an electric method to obtain injection pressure instead of the conventional hydraulic system, there is no need for a hydraulic unit, etc., and the entire device can be made very small and inexpensive, and its maintenance is also easy. The effect is that it becomes very easy.

[Brief explanation of drawings]

Fig. 1 is a front view showing an injection device of a molding machine according to an embodiment of the present invention, Fig. 2 is a partial top view taken from line - m in Fig. 1, and Fig. 3 is a front view showing an injection device of a conventional molding machine. A front view showing the device;
FIG. 4 is a partial top view taken from line IV--■ in FIG. 3. In the figure, (1) is the injection cylinder, (la) is the injection port, (2) is the piston, (2a) is the piston rod, (5
) indicates a servo mode. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) An injection device for a molding machine, characterized in that the piston of the injection cylinder is driven by a servo mechanism.