JPH045296Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a nozzle touch mechanism in an injection molding machine.

(Prior art) Conventionally, nozzle touch mechanisms for injection molding machines using electric motors have been disclosed in Japanese Patent Laid-Open No. 60-124227,
60-259419 is known. The former uses a servo motor to press and hold the nozzle against the mold, while the latter transmits the rotation of a servo motor with a brake to a screw shaft via gears, and the shaft is connected to the injection molding machine via a spring. It is connected to the main body and uses the compression force of the spring to press the nozzle against the mold.

(Problems with the prior art) Among the nozzle touch mechanisms of conventional injection molding machines, the former obtains the pressing force of the nozzle against the mold by the rotational force of the motor, so the motor must be energized at all times. However, it consumed a lot of electricity and was uneconomical. In addition, in the latter case, the pressing force of the nozzle is obtained by the elastic force of the spring, so there is no need to constantly energize the motor as in the former case.
The motor has to be equipped with a brake, which is expensive, and it also requires maintenance such as replacing the brake shoe.

(Purpose of the invention) The present invention was made in order to solve the above-mentioned conventional problems.It is an object of the present invention to simplify the nozzle touch mechanism of an electric injection molding machine, save energy, and facilitate maintenance. It is in.

(Means for Solving the Problems) The present invention transmits the rotation of an electric motor to a screw shaft through a deceleration mechanism consisting of a worm and a worm wheel, and supports the rotation of the screw shaft in a slidable manner via a nut. This is a nozzle touch mechanism of an injection molding machine that moves the injection molding nozzle forward and backward with respect to the mold by transmitting information to the injection molding machine main body. It is characterized by being movably supported by a spring inserted into the box.

(Example) An example of the present invention will be described below with reference to the drawings.
In FIG. 1, 1 is an injection molding machine main body, and the injection molding machine main body 1 has slides 5, 5 mounted on guide bars 4 supported by support yokes 3, 3' fixed to a molding machine frame 2. ' is slidably supported through.

The injection molding machine main body 1 is composed of an injection unit 6, an injection cylinder 7 connected to the unit 6, and a nozzle 8 provided at the tip of the cylinder 7. Further, a mold 9 attached to a mold opening/closing mechanism (not shown) is disposed in front of the nozzle 8.
A spring box 10 is constructed integrally with the slide shoe 5', and a spring 11 is inserted into the spring box 10. This spring 11 is in contact with one end surface of a nut which is supported at one end by the inner wall 10a of the spring box and slidably supported at the other end by the spring box 10. 13 is smooth and Natsu 1
2 is fixed to the slide shoe 5' so that it can slide in the axial direction but cannot rotate.
Reference numeral 14 is a threaded shaft that is screwed into the nut 12 and passes through the spring box 10, and one end passes through the support yoke 3 and extends into a gear box 15, which will be described later. Further, a limit switch 16 is attached to the outer surface 10b of the spring box 10 on the nut 12 side. The limit switch 16 is activated by the spring 11 when the injection molding machine body 1 moves toward the mold and the nozzle 8 is pressed against the mold 9.
is compressed by a predetermined amount.

The screw shaft 14 is supported by a bearing 17 on a gearbox 15 mounted on the support yoke 3'.
An input shaft 18 is fixed to the bearing 17 concentrically with the screw shaft 14 . A gearbox 15 is attached to the shaft 18.
A worm wheel 19 is pivotally attached within the gear box 15, and the worm wheel 19 meshes with a worm 21 fixed concentrically with the output shaft of an electric motor 20 mounted on the gear box 15, thereby forming a worm speed reduction mechanism. The reduction ratio of this worm reducer is such that even if rotational torque is applied from the worm wheel side, the worm 2
A reduction ratio is selected that has a so-called self-locking function in which gear 1 does not rotate.

(Function) When the electric motor 20 is driven and the output shaft is rotated, the worm 21 fixed concentrically with the output shaft rotates, and the worm wheel 1 meshing with the worm 21 rotates.
9 is rotated, and the input shaft 18 and screw shaft 14 are also rotated. This rotation of the screw shaft 14 causes the screw shaft 1 to
The nut 12 screwed into the screw shaft 4 also tries to rotate, but the nut 12 is prevented from rotating by the sliding key 13, and the nut 12 is moved along the screw shaft 14. This movement is transmitted to the slide shoe 5' via the spring 11 and spring box 10. Therefore, the injection molding machine main body 1 fixed to the slide shoe 5' moves along the guide bar 4, and the injection nozzle 8 comes into contact with the mold 9 (spring shoe). When the nozzle 8 contacts the mold 9, the nozzle 3 and the injection molding machine body 1 cannot be moved any further even if the electric motor 20 is moved further, so the spring 11 is moved to the spring box 10 by the nut 12.
The nut 1 is pressed against the inner wall of the nut 1 as shown in Figure 2.
2 enters into the spring box 11. This is detected by the operation of the limit switch 16, and the electric motor 20 is stopped, the injection unit 6 is activated, and the molten molding material in the injection cylinder 7 is injected from the nozzle 8 into the mold 9. Since the screw shaft 14 receives the reaction force of the spring 11 via the nut 12, the force that tries to relieve the compressive force of the spring 11, that is, the rotational force that tries to separate the nozzle 8 from the mold 9, is applied to the screw shaft 14.
However, since the worm wheel 19, which is pivotally attached to the input shaft 18 integral with the screw shaft 14, is engaged with the worm 21 in a self-locking manner, the screw shaft 14 is locked. Therefore, the nozzle 8 and the mold 9 are connected to the spring 1.
The abutting state is maintained with a compressive force equivalent to the compressive force applied to 1.

In the embodiment, the movement of the nut 12 is transmitted to the injection molding machine main body 1 and the nozzle 8 via the spring 11, but the spring 11 is not necessarily necessary and the limit switch is used to detect when the nozzle 8 has come into contact with the mold 9. 16 or the electric current flowing through the electric motor 20, and the electric motor 20 may be stopped.

(Effects of the invention) As described above, according to the invention, when the electric motor is stopped, the rotation of the screw shaft is prevented by the self-locking engagement between the worm wheel and the worm, and the nozzle and the mold are maintained in contact with each other. can do.
Further, by interposing a spring between the screw shaft and the injection molding machine main body, the nozzle and the mold can be held at a constant pressure by the compression force of the spring.

Therefore, there is no need to use a brake-equipped electric motor as in the past, or to constantly energize the electric motor in order to obtain a constant pressure contact force, which facilitates the maintenance of the device and has the effect of saving energy.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of an embodiment of the present invention, FIG. 2 is a cross-sectional view of the spring box during injection, and FIG. 3 is a diagram showing the positional relationship of gears in the speed reduction mechanism. 1... Injection molding machine main body, 6... Injection unit,
7...Cylinder, 8...Nozzle, 9...Mold, 1
0... Spring box, 11... Spring, 12... Nut, 14... Screw shaft, 16...
Limit switch, 18... Input shaft, 19... Worm wheel, 20... Electric motor, 21... Worm.

Claims (1)

[Claims for Utility Model Registration] 1. In a nozzle touch mechanism of an injection molding machine, the rotation of an electric motor is transmitted to a screw shaft through a reduction mechanism consisting of a worm and a worm wheel, and the rotation of the screw shaft is transmitted through a nut. A nozzle touch mechanism for an injection molding machine that moves a nozzle of the injection molding machine forward and backward relative to a mold by transmitting information to a main body of the injection molding machine that is supported by the main body of the injection molding machine. 2. Injection molding according to claim 1 of the utility model registration claim, characterized in that a nut screwed onto a screw shaft is movably supported by a spring inserted into a spring box attached to the main body of an injection molding machine. Machine nozzle touch mechanism.