JP2002355868A - Injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding machine which is capable of preventing metal parts from being damaged by avoiding a direct collision between the parts at stroke limits and thereby ensuring a positive operation. SOLUTION: This injection molding machine comprises mold halves 22 and 27, a barrel 43 which has a hollow part 43a communicating with a space of the mold halves 22 and 27 and also a heating means 45 for thermally melting a raw resin material received into the hollow part 43a, a screw 47 which is inserted into the hollow part 43a and driven forward/backward in the axial direction and a linear motor moving element 10 having an output shaft 13 connected to the rear end part of the screw 47 for moving the output shaft 13 in the axial direction so that the molten resin is injected into the space of the mold halves 22 and 27 from the hollow part 43a. In addition, in this machine, a mount part 16 which has a linear guide 18a for supporting and guiding the linear motor moving element 10 and impact absorbing members 19 and 60 which are installed at a region, of the mount part 16, where the linear motor moving element 10 is about to collide at stroke limits and absorbs and reduces an impact force to be generated by the collision of the moving element 10 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for injecting and molding a molten resin into a mold.

[0002]

2. Description of the Related Art As shown in FIG. 1, an injection molding machine 1 is formed between a fixed mold 22 fixed to a fixed platen 21 and a movable mold 27 movably supported by a toggle mechanism 29. The resin melted in the gap is injected from the heating barrel 43 of the injection unit 40 and molded by the movable mold 27 driven by the toggle mechanism 29 to form a molded product 53.

A screw 47 is inserted into a hollow portion 43a of the heating barrel. The screw 47 has a pulley 52
The rotation drive shaft of a measuring motor (AC servo motor) 51 is connected via the. And the screw 47 is driven to rotate. The output shaft 13 of an injection motor (linear motor) 49 is connected to the screw 47 so that the screw 47 is driven forward. Further, the entirety of the injection unit 40 is mounted on the movable base 42, and the movable base 42 is moved in the axial direction on the frame 20 by the nozzle touch motor 41, so that the entirety of the injection unit 40 becomes the axis of the screw 47. It is designed to move forward or backward in the direction.

The movable platen 28 has both fixed and movable dies 2.
An extrusion pin 54 for extruding the molded product 53 formed by the molds 2 and 27 from the movable mold 27 and a molded product extrusion motor 55 for moving the extrusion pin 54 forward and backward are provided.

[0005]

However, in the conventional injection molding machine, screw driving by the linear motor 49 enables high-speed injection, but on the other hand, when metal parts collide due to control mistakes or the like. In this case, there is a possibility that the metal parts are greatly damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and it is possible to prevent a direct collision between metal parts at the time of a stroke limit, to prevent damage to the parts, and to perform a reliable operation. An object is to provide a molding machine.

[0007]

In order to solve the above-mentioned problems, an injection molding machine according to the present invention is an injection molding machine that performs an operation of injecting molten resin using a linear motor. A barrel having a hollow portion communicating with the cavity of the mold and having a heating means for heating and melting the resin raw material received in the hollow portion, and a screw inserted into the hollow portion and driven to advance and retreat in the axial direction; A moving element of a linear motor having an output shaft connected to the rear end of the screw, and moving the output shaft in the axial direction so that the molten resin is injected from the hollow portion toward the cavity of the mold. A mounting portion having a linear guide for supporting and guiding the moving element of the linear motor; and a mounting portion to which the moving element of the linear motor is likely to collide during a stroke limit. Is characterized in that and a cushioning member to reduce by absorbing the impact force resulting from the collision of the elements of movement of the linear motor.

In the injection molding machine of the present invention, since the cushioning member is provided at the position of the mount where the moving element of the linear motor is to collide, collision of the metal parts at the time of stroke limit is avoided, and Damage is prevented, most of the impact force generated by the collision is absorbed by the buffer member, the stroke amount of the screw becomes highly accurate, and a reliable injection operation is ensured.

The cushioning member is not limited to a complicated structure such as a hydraulic damper, but a sufficient function can be obtained by a spring or a urethane cushion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, FIGS. 1 and 2
A first embodiment of the present invention will be described with reference to FIG.

FIG. 1 is an overall configuration diagram showing an outline of an injection molding machine according to an embodiment of the present invention. A fixed board 21 is fixed on the frame 20, and a mold 22 is fixed on the front side of the fixed board 21. A through hole is formed in the center of the fixed mold 22 and communicates with the hollow portion 43a of the heating barrel of the injection unit 40 provided at the rear. A hopper 44 and a heater 45 are respectively attached to the heating barrel 43 at appropriate locations, and the resin material supplied from the hopper 44 to the hollow portion 43 a of the heating barrel is heated and melted by the heater 45.

A screw 47 is inserted into the hollow portion 43a of the heating barrel. The screw 47 has a pulley 52
The rotation drive shaft of a measuring motor (AC servo motor) 51 is connected via the. And the screw 47 is driven to rotate. The output shaft 13 of an injection motor (linear motor) 49 is connected to the screw 47 so that the screw 47 is driven forward. Further, the entirety of the injection unit 40 is mounted on the movable base 42, and the movable base 42 is moved in the axial direction on the frame 20 by the nozzle touch motor 41, so that the entirety of the injection unit 40 becomes the axis of the screw 47. It is designed to move forward or backward in the direction. Note that the heating barrel 43 is attached to the front side of the movable base 42.

A nozzle 46 is formed at the tip of the heating barrel 43. When the movable table 42 is moved forward,
The nozzle 46 fits into the recess of the fixed board 21 and the nozzle 46
Are connected to the through holes of the fixed mold 22 so that the molten resin is injected from the hollow portion 43 of the heating barrel into the space between the fixed mold 22 and the movable mold 27.

On the other hand, a toggle mechanism 29 is provided on the front side of the fixed board 21. The toggle mechanism 29 includes the movable mold 2
7 is movably held in the axial direction, and the movable mold 27 is fixed to the fixed mold 2.
2, or a mechanism for separating the movable mold 27 from the fixed mold 22. Support plate 23 of toggle mechanism 29
Are supported by the frame 20 so that they can slide on the frame 20 in the axial direction.

A plurality of tie bars 24 are provided between the fixed board 21 and the toggle mechanism support board 23. One end of each tie bar 24 is fixed at an appropriate position on the periphery of the fixed platen 21, and the other end is movably engaged with the toggle mechanism support plate 23.

The toggle mechanism support board 23 is moved on the frame 20 along the tie bar 24 by a female screw (not shown) provided on a gear 26 rotated by a mold thickness adjusting motor 25 and a male screw provided on the tie bar 24. And is fixed at a predetermined position.

A movable plate 28 on which a movable mold 27 is mounted is movably engaged with the tie bar 24, and a toggle mechanism 29 is provided between the movable plate 28 and the toggle mechanism support plate 23. The toggle mechanism 29 has a crosshead 31 which is advanced and retracted in parallel with the tie bar 24 by a mold clamping motor 30. By moving the cross head 31 forward and backward, the movable platen 28 is moved in the axial direction, and the opening and closing of the movable mold 27 to and from the fixed mold 22 and the closing operation of the mold are performed.

A screw 47 is engaged with the heating barrel 43 so as to rotate and move forward and backward. An injection motor (hereinafter, referred to as a linear motor) 4 composed of a linear motor according to the present invention is connected to the base end of the screw 47 via a rotary joint 48.
9. A spline 50 is provided on the tip side of the rotary joint 48 of the screw 47, and the screw 47 is rotated at a predetermined rotation speed by a pulley 52 that is rotated by a measuring motor 51 such as an AC servomotor. I have.

The movable platen 28 is provided with a molded product 53 formed by the fixed and movable dies 22, 27.
7 and an extrusion pin 54 for extruding
Is provided with a motor 55 for extruding a molded product.

Next, the linear motor 49 of the first embodiment will be described with reference to FIG. Linear motor 4
9 is entirely covered with an outer casing 16, and an output shaft 13 protrudes from one end surface of the casing 16.
The output shaft 13 has its tip end connected to the rear end of the screw 47 via a rotary joint 48 and the like, and its rear end side connected to the movable plate 1.
4 attached. The movable plate 14 is movably supported by one or more pairs of linear guides 15 by a plurality of pairs of bearings 18a. Each linear guide 15 has an output shaft 13
The casing 16 is provided from one end face to the other end face of the casing 16 so as to be parallel. A coil 16 and a magnet 12 are provided in the casing 16 as the moving element 10 of the linear motor.

The coil 11 is provided on the left and right surfaces of the coil holder 17 attached to the casing 16 in FIG. 2, that is, on the surface perpendicular to the upper surface of the movable plate 14 and parallel to the moving direction of the movable plate 14. .

The magnet 12 is held by a magnet holder 18, and the magnet holder 18 is attached to the movable plate 14. Also,
The magnet holder 18 includes a plurality of bearings 18a, and the magnet holder 18 is movably supported by the linear guide 15 by these bearings 18a.

Dampers 19 serving as shock absorbing members are mounted at four positions inside and behind the casing 16 to prevent direct collision between the moving element 10 of the linear motor and the casing 16 at the time of the stroke limit, and to prevent the linear motor from moving. The impact force generated by the collision of 10 is absorbed. In this case, the damper 19
Is the weight of the member such as the movable plate 14, the injection speed,
From conditions such as the stroke of the damper, it is preferable to set a numerical value sufficient to absorb energy generated at the time of collision. The damper 19 may be a hydraulic or pneumatic mechanism.

According to the injection molding machine of this embodiment, since the dampers 19 are provided at both the right and left dead points of the linear guide 15, the impact force due to the collision of the moving element 10 of the linear motor is absorbed by the dampers 19. In addition, a high-speed injection operation can be performed safely and reliably. Further, damage to metal parts such as the movable plate 14, the casing 16, the magnet holder 18, and the like is prevented, and the life of these metal parts is greatly extended.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG.

In the injection molding machine of the second embodiment, compression springs 60 are provided as shock absorbing members at both left and right ends of the inner surface of the casing 16 of the linear motor 49A. In this case, the large-diameter compression springs 60
One or two (two to eight) small-diameter compression springs 60 may be attached to each of the left and right sides.

In the above embodiment, a compression spring is used as the cushioning member, but a cushion made of hard or soft urethane foam having various hardnesses may be used instead.

[0029]

According to the present invention, since the cushioning member is provided at the mount portion where the moving element of the linear motor is to collide, most of the impact force generated by the collision at the time of the stroke limit is reduced. As a result, the stroke amount of the screw becomes highly accurate, and a reliable injection operation is guaranteed.

Further, according to the present invention, the shock-absorbing member prevents direct collision between the metal parts at the time of the stroke limit, prevents the metal parts from being damaged, and greatly extends the life of the metal parts.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an outline of an injection device.

FIG. 2 is an internal perspective sectional view showing the injection device according to the first embodiment of the present invention.

FIG. 3 is an internal perspective sectional view showing an injection device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Moving element of a linear motor, 11 ... Coil, 12 ... Magnet, 13 ... Output shaft, 14 ... Movable plate, 15 ... Linear guide, 16 ... Casing (mounting part), 17 ... Coil holder, 18 ... Magnet holder, 18a ... bearing, 19 ... damper (buffer member), 20 ... frame, 21 ... fixed plate, 22 ... fixed die, 23 ... toggle mechanism support plate, 24 ... tie bar, 25 ... mold thickness adjustment motor, 26 ... gear, 27 ... moving mold, 28 ... moving board, 29 ... toggle mechanism, 30 ... clamping motor, 31 ... cross head, 40 ... injection unit, 41 ... nozzle touch motor, 42 ... movable table, 43 ... heating barrel, 44 ... hopper, 45 ... heater, 46 ... nozzle, 47 ... screw, 48 ... rotary joint, 49,49A ... injection motor (linear motor), 50 ... splice , 51 ... metering motor, 52 ... pulley, 53 ... moldings, 54 ... extrusion pin, 55 ... moldings extrusion motor, 60 ... compression spring (cushioning member).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuyoshi Kido inventor, 2068-3 Ooka, Numazu-shi, Shizuoka Pref. (72) Harumichi Tokuyama 2068-3, Ooka, Numazu-shi, Shizuoka F-term in Toshiba Machine Co., Ltd. (Reference) 4F206 AM04 AM24 JA04 JD03 JM01 JM04 JT02 JT32

Claims (3)

[Claims] 1. An injection molding machine for performing an injection operation of molten resin using a linear motor, comprising: a mold; and a hollow portion communicating with a cavity of the mold, wherein the resin raw material received in the hollow portion is provided. A barrel provided with a heating means for heating and melting, a screw inserted into the hollow portion and driven in the axial direction, and an output shaft connected to a rear end of the screw; A moving element of a linear motor that moves the output shaft in the axial direction so as to be ejected from the hollow part toward the cavity of the mold; and a mounting part having a linear guide for supporting and guiding the moving element of the linear motor. At the time of a stroke limit, the linear motor is attached to the mount portion where the moving element of the linear motor is about to collide, and absorbs the impact force generated by the collision of the moving element of the linear motor. An injection molding machine, comprising: a buffer member for reducing the pressure. 2. The injection molding machine according to claim 1, wherein a spring is used for said buffer member. 3. The injection molding machine according to claim 1, wherein a urethane cushion is used for the cushioning member.