JP3237636B2 - Injection molding machine - Google Patents

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 capable of moving an injection unit back and forth with respect to a mold and rotating the same.

[0002]

2. Description of the Related Art In a conventional injection molding machine, a mold for forming a cavity, an injection unit for injecting a resin into the cavity in contact with the mold, and an injection unit for moving back and forth and rotating with respect to the mold. And an injection unit moving mechanism unit for performing the above. The injection unit moving mechanism of the injection molding machine converts the rotational force of the brake motor, which is always braked when stopped, the deceleration unit for decelerating the rotation of the brake motor and the brake motor decelerated by the deceleration unit, into linear motion. Thus, a drive unit including a linear operating unit for moving the injection unit with respect to the mold, and a thrust limiter unit for pressing the injection unit against the mold and stopping the unit are provided separately.

[0003]

As described above, if the drive unit and the thrust limiter unit of the injection unit moving mechanism are separately provided, the injection unit moving mechanism becomes larger as a whole, as a matter of course. In addition, there has been a problem that workability in assembly work and adjustment work is poor. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an injection molding machine capable of reducing the size of an injection unit moving mechanism and improving workability in assembling work and adjusting work of the injection unit moving mechanism. .

[0004]

In order to achieve the above object, an injection molding machine of the present invention is provided on a machine base so as to be movable.
Movable type and fixed type fixed to machine base via fixed platen
And a mold that joins to form a cavity, an injection unit that injects a resin into the cavity by contacting the mold, and an injection unit that moves the injection unit forward and backward with respect to the mold. be one having a moving mechanism portion, the injection unit moving mechanism includes a brake motor according always braking when stopping, a decelerating portion for decelerating the rotation of the brake motor, a brake motor is decelerated by the deceleration portion A linear actuating unit that moves the injection unit with respect to the mold by converting the rotational force of the injection unit into a linear motion, and a thrust limiter unit that presses and stops the injection unit against the mold are unitized into one unit , Both ends
It is characterized by comprising an electric cylinder connected to a fixed platen and an injection unit .

As described above, the brake motor that always brakes when stopped, the deceleration unit that decelerates the rotation of the brake motor, and the rotational force of the brake motor decelerated by the deceleration unit are converted into linear motion. Since the linear operation unit that moves the injection unit with respect to the mold and the thrust limiter unit that presses and stops the injection unit against the mold, the injection unit moving mechanism unit is configured by a unitized electric cylinder, The injection unit moving mechanism can be made compact. In addition, since the injection unit moving mechanism can be assembled and adjusted as a unit in advance, workability in the assembling operation and the adjusting operation can be improved.

[0006]

FIG. 1 shows a first embodiment of the present invention.
This will be described below with reference to FIG. The injection molding machine according to the first embodiment includes a machine base 10, a mold 11 arranged on the machine base 10 to form a cavity (not shown), It has an injection unit 12 for injecting resin, and an electric cylinder 13 as an injection unit moving mechanism for moving the injection unit 12 forward and backward and turning with respect to the mold 11.

The mold 11 comprises a movable mold 15 movably provided on the machine base 10 and a fixed mold 17 fixed to the machine base 10 via a fixed plate 16. A cavity (not shown) is formed by joining the mold 15 and the fixed mold 17.

The injection unit 12 is slidably provided on a slide base 20 provided on the machine base 10. The injection unit 12 passes through the fixed platen 16 at the nozzle 21 at the tip, and the nozzle touch portion 22 of the fixed die 17
The resin is injected into the cavity in this contact state.

The slide base 20 is switched between a state in which the slide base 20 is fixed to the machine base 10 and a state in which the slide base 20 can be horizontally turned around the turning center 19. Slide base 20
Is provided with a nozzle height adjusting bolt 23 for adjusting the height of the nozzle 21 of the injection unit 12 by adjusting the height of the slide base 20 with respect to the machine base 10.

The electric cylinder 13 is interposed between the fixed platen 16 and the injection unit 12.
Is fixed on the fixed plate 16 while sliding the
That is, the injection unit 12 is caused to move forward and backward with respect to the mold 11, and the injection unit 12 is horizontally turned together with the slide base 20 as necessary.

The electric cylinder 13 is, as shown in FIG.
A brake motor 25 that always brakes when stopped,
A speed reduction unit 26 for reducing the rotation of the brake motor 25 at a predetermined reduction ratio, a ball screw mechanism unit (linear operation unit) 27 for converting the rotational force of the brake motor 25 reduced by the speed reduction unit 26 into linear motion, Injection unit 12 into mold 11
And a thrust limiter unit 28 for stopping the pressing. In addition, the brake motor 25 may be one in which the brake and the motor are individually arranged without being integrated.

The ball screw mechanism 27 includes a ball screw 3
0, a ball nut 31 and a ball (not shown), an outer tube portion 32 covering these, and an inner tube portion 33 partially fitted inside the outer tube portion 32, and are decelerated by the speed reduction portion 26. When the ball screw 30 is rotated by the rotational force of the brake motor 25, the ball nut 31 moves forward and backward by the rotational force of the ball screw 30, and the inner cylinder 33 connected to the ball nut 31 moves relative to the outer cylinder 32. Go back and forth. Note that the ball screw 30 and the ball nut 31 may be replaced with a normal screw (trapezoidal screw or the like) and a nut. In this case, the self-locking function of the screw portion can make the brake unnecessary.

The side of the speed reduction section 26 opposite to the ball screw mechanism section 27 of the casing 34 is connected to the fixed plate 16 via a spherical bearing 35, and the opposite side of the inner cylinder section 33 to the reduction section 26 is a spherical bearing 36 (see FIG. 1) via the injection unit 1
2 Thus, when the slide base 20 is fixed to the machine base 10, the inner cylinder 33 moves forward and backward by the rotational force of the brake motor 25, and as a result,
The injection unit 12 moves forward and backward on the slide base 20. On the other hand, in a state where the slide base 20 is released from being fixed to the machine base 10, the rotation of the brake motor 25 causes the inner cylinder 33 to move forward and backward.
And the slide base 20 turns integrally around the turning center. When the amount of adjustment of the center height of the nozzle 21 and the nozzle touch portion 22 is very small, the spherical bearings 35 and 36 may be a normal pin-type coupling.

The thrust limiter 28 is provided between the ball screw 30 and the speed reducer 26, and comprises an LS section 38 for detecting the axial movement of the ball screw 30 and a spring unit 39 for urging the ball screw 30. Have been. When an overload occurs, the thrust limiter unit 28 causes the inner cylinder portion 33 to move against the outer cylinder portion 32 against the urging force of the spring unit 39.
Moves with the ball screw 30 with respect to
A limit switch (not shown) of the unit 38 detects the signal. Then, utilizing this, the brake motor 2
As a result, the injection unit 12 is moved forward by driving the nozzle unit 5 and the nozzle 21 is brought into contact with the nozzle touch portion 22 of the fixed mold 17, so that the ball screw 30 is pressed against the urging force of the spring unit 39.
Is detected by the LS unit 38 and the advance of the injection unit 12 is stopped by stopping the brake motor 25, and the injection unit 12 is pressed against the fixed mold 17 by the urging force generated in the spring unit 39 at that time. It stops in a state.

According to the injection molding machine of the first embodiment described above, the brake motor 25 that always brakes when stopped, the speed reduction unit 26 that reduces the rotation of the brake motor 25, and the speed reduction unit 26 A ball screw mechanism 27 that moves the injection unit 12 with respect to the mold 11 by converting the rotational force of the brake motor 25 decelerated into linear motion, and a thrust limiter 28 that presses and stops the injection unit 12 against the mold 11. Since the injection cylinder moving mechanism for moving the injection unit 12 is constituted by the unitized electric cylinder 13, the injection unit moving mechanism can be made compact. Moreover, since the electric cylinder 13 can be assembled and adjusted as a unit in advance, the workability in the assembling operation and the adjusting operation can be improved.

In addition, since the electric cylinder 13 is connected to the fixed platen 16 and the injection unit 12 via the spherical bearings 35 and 36 at both ends, the centering of the nozzle 21 of the injection unit 12 to the mold 11 and injection. When the unit 12 moves forward and backward, and when the injection unit 12 turns, etc.,
Undesirable twisting (bending) of the electric cylinder 13 can be prevented.

Next, a second embodiment of the present invention will be described below with reference to FIG. 3, focusing on differences from the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the second embodiment, the inner cylinder 33
Is formed with a flange portion 41.
Is fixed to a support shaft 42 extending parallel to the axis of the ball screw mechanism 27. A dog 43 is fixed to the support shaft 42 at a predetermined intermediate position, and a plurality of limit switches 44, 4 which are turned on by the dog 43 are provided.
5, 46 are provided. These limit switches 4
The positions of the dog 43, that is, the position of the inner cylindrical portion 33 are detected by 4, 45, and 46.

That is, the limit switch 44 closest to the fixed board 16 is arranged at a position where it is turned on by the dog 43 when the injection unit 12 advances to the limit position in the direction of the fixed mold 17. On the other hand, the limit switch 45 adjacent to the injection unit 12 is located at a position where it is turned on by the dog 43 when the injection unit 12 retreats to the limit position in the opposite direction with respect to the fixed mold 17. In contrast, the limit switch 46 adjacent to the injection unit 12 is located at a position where the dog 43 is turned on when the injection unit 12 and the slide base 20 have turned to the turning completion position.

The LS section 38 has a dog 48 that moves integrally with the ball screw 30, and limit switches 49 and 50 disposed before and after the dog 48. And
The limit switch 49 on the fixed board 16 causes the injection unit 12 to move forward by the driving of the brake motor 25 to bring the nozzle 21 into contact with the nozzle touch portion 22 of the fixed die 17, and as a result, the limit switch 49 resists the urging force of the spring unit 39 It is turned on when the ball screw 30 moves.

[0021]

As described above in detail, the injection molding machine of the present invention has a brake motor which is always braked when stopped, a speed reduction unit for reducing the rotation of the brake motor, and a brake speed reduced by the speed reduction unit. An electric cylinder in which a linear operating unit that moves the injection unit with respect to the mold by converting the rotational force of the motor into a linear motion, and a thrust limiter unit that presses and stops the injection unit against the mold. Since the injection unit moving mechanism is constituted by the above, the injection unit moving mechanism can be made compact. In addition, since the injection unit moving mechanism can be assembled and adjusted as a unit in advance, workability in the assembling operation and the adjusting operation can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view (a) and a side view (b) showing a first embodiment of an injection molding machine of the present invention.

FIG. 2 is a side sectional view showing an electric cylinder according to the first embodiment of the injection molding machine of the present invention.

FIG. 3 is a side sectional view showing an electric cylinder according to a second embodiment of the injection molding machine of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Die 12 Injection unit 13 Electric cylinder (injection unit moving mechanism part) 25 Brake motor 26 Reduction part 27 Ball screw mechanism part (linear operation part) 28 Thrust limiter part

Claims (1)

(57) [Claims] A movable type movably provided on a machine base;
A mold that is joined to a fixed mold fixed to the machine base via a fixed plate to form a cavity, and an injection unit that contacts the mold and injects resin into the cavity. An injection molding machine having an injection unit moving mechanism for causing the injection unit to move forward and backward with respect to the mold and to rotate, wherein the injection unit moving mechanism includes a brake motor that always applies a brake when stopped, A deceleration unit for decelerating the rotation of the rotation unit, a linear operation unit for moving the injection unit with respect to the mold by converting the rotational force of the brake motor decelerated by the reduction unit to linear motion, and the injection unit A thrust limiter unit that stops pressing against the mold is unitized into one unit, and both ends are fixed plates.
And an electric cylinder connected to the injection unit .