JPH0317658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a nozzle touch device for an injection molding machine using an electric motor as a driving force.

[Prior Art] In a conventional hydraulically operated injection molding machine, a hydraulic cylinder device is provided between the fixed plate of the mold clamping device and the injection device, and the injection device is fixed by the linear movement of the piston of the hydraulic cylinder device. Attract it to the board side,
Performing nozzle touch.

[Problems to be Solved by the Invention] Even in electric injection molding machines, nozzle touching can be performed using a hydraulic cylinder device, but a hydraulic drive device must be installed for nozzle touching in addition to the electric motor for mold clamping and injection drive. This is not only uneconomical but also inconvenient to control, so it is necessary to use an electric motor to turn the nozzle.

The present invention has been conceived in view of the above circumstances, and its object is to provide a nozzle touch device for an injection molding machine that can reliably touch the nozzle with a simple configuration and that can easily control the nozzle touch using an electric motor.

[Means for Solving the Problems] The present invention according to the above object is characterized by a nozzle touch member in which the tip of the shaft portion is formed into a screw shaft, and a screw receiving member provided on the lower side of the fixed platen of the mold clamping device. The nozzle touch member is horizontally and rotatably provided below the injection device that moves relative to the fixed plate, the screw shaft protrudes toward the fixed plate, and is screwed into the screw receiving member so as to be freely retractable. The injection device is connected to a fixed plate, and the shaft portion is connected to a transmission shaft rotated by an electric motor.

[Operation] In the nozzle touch device configured as described above, when the rotational force of the electric motor is transmitted to the nozzle touch member via the transmission shaft, the screw shaft rotates together with the shaft portion. Since the screw receiving member that this screw shaft is threaded into is in a fixed state, the nozzle touch member side moves with the injection device relative to the fixed plate, and the nozzle touch is performed when the motor is rotating in the forward direction, and vice versa. During rotation, the nozzle touch is released.

Hereinafter, the present invention will be explained in more detail with reference to illustrated embodiments together with an electric injection molding machine.

[Example] In the figure, 1 indicates a mold clamping device, and 2 indicates an injection device. The mold clamping device 1 includes a tie bar 12 installed on a pair of fixed plates 10 and 11 on a machine stand 3, and a movable plate 13 movably attached to the tie bar 12. Molds 14, 14 are provided on opposing surfaces of the fixed plate 11 and the movable plate 13, respectively, and the movable plate 1
A screw shaft 15 is provided protruding from the opposite surface of 3. This screw shaft 15 is screwed into a rotary disk 16 that is rotatably attached to the other fixed plate 10, and the rotary disk 16
A gear 17 is attached to the gear 17.
When the rotary plate 16 rotates, the screw shaft 15 moves together with the movable plate 13 by means of a screw lead, forming a mold opening/closing device.

The injection device 2 includes an injection heating cylinder 21 having a screw 20 therein, and a housing 22 that is movable with respect to a fixed plate on a machine base that also serves to hold the injection heating cylinder 21. There is a screw 2 inside the housing 22.
0 and a pair of support shafts 24, 24 installed on both sides in parallel with the screw, and a screw holding member 25 is attached to the support shafts 24, 24 so as to be slidable in the front and back direction.

Further, an extension shaft 27 having a screw rotation gear 26 is connected to the rear end of the screw 20, and the end of the extension shaft 27 is attached to the screw holding member 25.
It is rotatably connected to.

Furthermore, a screw shaft 30 is screwed into a screw receiving member 28 provided at the rear of the screw holding member 25, which is rotatably held by the housing wall 22a and is integral with a shaft portion 30a having an injection gear 29. The outer end of the shaft portion 30a is connected to the housing wall portion 2.
It is connected to a brake device 31 fixed to 2a. This brake device 31 is equipped with a hysteresis brake inside.

Reference numeral 32 denotes a transmission shaft on the mold clamping device side, which is rotatably supported on the lower part of the fixed plates 10 and 11 and has a transmission gear 17a at its outer end that is close to the fixed plate 10 and meshes with the gear 17. However, a key or spline 32a is provided at the inner end.

Reference numerals 33 and 34 denote transmission shafts on the injection device side, which are supported in parallel in the lower part of the housing 22, and the transmission shafts 33 and 34 are connected to transmission gears 35 and 35 respectively attached to the transmission shafts.
36, so that they rotate at the same time.

Further, a drive belt 38 is provided to extend between the outer end of the transmission shaft 34 and a servo motor 37 installed on the lower side of the housing, and the servo motor 37 rotates both the transmission shafts 33 and 34. Note that 39 is a belt wheel.

A joint 40 for connecting the transmission shaft 32 of the mold clamping device is connected to the inner end of the transmission shaft 33 via an electromagnetically actuated clutch device 41 so as to be freely accessible and detachable.

Note that 41a is a clutch plate, and 41b is a clutch exciter.

This joint 40 includes a shaft portion 40a that is rotatably supported by the housing 22, and a cylinder that is integrally formed on the outer end of the shaft portion 40a and has a keyway or spline on the inside that receives the inner end of the transmission shaft 32. 40b, and an electromagnetic brake 42 is further provided on the shaft portion 40a. This electromagnetic brake 42
is a brake plate 42a fixed to the housing wall 22a.
and an electromagnetic device 42b which is keyed to the shaft portion 40a.The electromagnetic device 42b is coupled to the brake plate 42a by excitation, and maintains the mold clamping force via the transmission shaft 32.

Further, at the inner end of the transmission shaft 34, a nozzle touch member 43 for connecting the fixed platen 11 on the mold clamping device side and the housing 22 is rotatably supported by the housing 22.

This nozzle touch member 43 has a shaft portion 43a,
It consists of a screw shaft 43b at the tip that is screwed into the screw receiving member 11a attached to the fixed platen 11, and the shaft portion 4
3a is horizontally and rotatably provided on the lower side of the housing of the injection device, with a screw shaft 43b protruding toward the stationary platen and screwed into the screw receiving member 11a so as to be freely retractable. Further, at the rear end of the shaft portion 43, a transmission shaft 34 is connected between the shaft ends of an electromagnetically actuated clutch device 4.
4, and thereby the transmission shaft 34 and the nozzle touch member 43 are connected in a freely connectable and disconnectable manner.

The clutch device 44 is composed of a clutch plate 44a attached to the shaft portion 43a side and a clutch exciter 44b attached to the transmission shaft 34 side.

Further, an electromagnetic brake 45 is provided on the shaft portion 43a. This electromagnetic brake 45 is connected to the housing wall 2
The brake plate 45a is fixed to the brake plate 2a, and an electromagnetic device 45b is keyed to the shaft portion 43a so as to be movable in the axial direction.

In the figure, reference numeral 46 denotes a transmission gear provided on the transmission shaft 33 together with an electromagnetically actuated clutch device 47, which meshes with the injection gear 29. A transmission gear 48 is provided on the transmission shaft 34 together with an electromagnetically actuated clutch device 49, and meshes with the screw rotation gear 26.

Next, the injection molding process will be explained.

The clutch device 41 shown in FIG.
With 2 and 33 connected, the servo motor 37
rotate in the forward direction. At this time, on the injection device 2 side, the transmission gear 4 is opened by the opening operation of the clutch devices 47 and 49.
Leave 6,48 in a free state. Also, the transmission shaft 34
and the nozzle touch member 43.
4 is also opened and the connection between the two is cut off. On the mold clamping device side, the rotary disk 16 is rotated by the transmission shaft 32, the transmission gear 17a, and the gear 17, and the screw shaft 15 is fed out.

As a result, the movable platen 13 moves forward and the mold 1
4 and 14 are closed, and further strong mold clamping is performed. When the mold clamping pressure reaches a predetermined pressure, the electromagnetic device 42b at the joint 40 is energized to fix the transmission shaft 32 to the housing side and maintain the mold clamping force. When such a stroke is completed, the clutch device 41 is opened to disconnect the transmission shaft 33, and following this operation, the injection device side operates the clutch device 44 to close in response to a command, thereby disconnecting the transmission shaft 34 and the nozzle touch. It connects with member 43 and rotates at the same time. This rotation causes the screw shaft 43b to enter into the fixed platen and pull the housing 22. At this time, since the transmission shaft 32 is connected to the transmission shaft 33 via the joint 40 so as to be able to freely slide in the axial direction, the housing 22 moves on the machine base toward the fixed platen 11 regardless of the transmission shaft 33. ,
A nozzle touch occurs there.

When the nozzle touch is confirmed by a forward movement confirmation sensor or the like, the electromagnetic device 45b is energized by electricity, and the shaft portion 43a is coupled to the brake plate 45a.
Maintain nozzle touch force. Further, following this operation, the power to the clutch exciter 44b is cut off, and the connection between the transmission shaft 34 and the nozzle touch member 43 is released.

Next, the clutch device 47 is operated to close according to the command, connecting the transmission shaft 33 and the transmission gear 46, and rotating the injection gear 29 together with the screw shaft 30. The rotation of the screw shaft 30 moves the screw holding member 25 forward, pushes out the screw 20, and injects molten resin into the molds 14, 14 of the mold clamping device 1 which are in a strong mold clamping state.

When the injection is completed, the servo motor 37 is stopped, and at the same time, the clutch device 47 is opened in response to a command, thereby freeing the transmission gear 46 relative to the transmission shaft 33. Further, the clutch device 44 is operated to close the transmission shaft 34 to reconnect the transmission shaft 34 and the screw shaft 43b. Then, when the servo motor 37 rotates in the reverse direction according to the command, the screw shaft 43b also rotates in the reverse direction, pushing the housing 22 back to its original direction and releasing the nozzle touch. This confirmation is performed by the reverse completion sensor. Further, the screw rotation gear 26 is rotated by the transmission gear 48, the screw 20 is also rotated together, and charging of the material is started. When the charging of the material is completed, the servo motor 37 is temporarily stopped and the clutch device 49 is released.

On the mold clamping device 1 side, when pressure holding for a predetermined period of time is completed, power to the electromagnetic brake 42 is cut off, and the coupling between the brake plate 42a and the electromagnetic device 42b is released. Continuing with this operation, the clutch device 41 is operated to close, and the transmission shaft 33 and the transmission shaft 32 on the mold clamping device side are connected to each other.
The servo motor 27 is rotated in the reverse direction by connecting the servo motor 27 again. As a result, the rotary disk 16 rotates in the opposite direction, and the screw shaft 15 moves backward to its original position to open the mold.

As described above, this invention consists of a nozzle touch member in which the tip of the shaft portion is formed into a screw shaft, and a screw receiving member provided below a fixed plate of a mold clamping device, and the nozzle touch member is connected to the fixed plate. The injection device is horizontally and rotatably provided below the moving injection device, the screw shaft protrudes toward the fixed plate, and is screwed into the screw receiving member so as to be movable forward and backward, thereby connecting the injection device to the fixed plate, and Since the shaft portion and the transmission shaft rotated by the electric motor are connected, the nozzle can be reliably touched even when the electric motor is used as the driving source.

In addition, the nozzle touch force can be maintained by detecting the current flowing through the motor, and by regulating the maximum output of the motor during the nozzle touch stroke to a preset value, the time required to reach the maximum output can be controlled. It also has the advantage of being able to measure and control it with a timer, etc., and has a simple configuration, so there are fewer failures, and when a DC servo motor is used as the electric motor, the operation becomes smoother and the performance is further improved. It has characteristics.

[Brief explanation of the drawing]

The drawings illustrate an electric injection molding machine using the force holding method according to the present invention, in which Fig. 1 is a front view, Fig. 2 is a longitudinal sectional front view of the mold clamping device, and Fig. 3 is a view of the injection device. FIG. 4 is a cross-sectional plan view of the housing on the injection device side, and FIG. 5 is a cross-sectional view taken along the line of FIG. 1. 1... Mold clamping device, 2... Injection device, 3... Machine stand, 14... Mold, 11... Fixed plate, 11a...
Screw receiving member, 15... Screw shaft, 16... Turning plate, 20... Screw, 22... Housing, 3
2, 33, 34...Transmission shaft, 42...Electromagnetic brake, 43...Nozzle touch member, 43a...Shaft portion, 43b...Screw shaft, 45...Electromagnetic brake.

Claims (1)

[Claims] 1 Consisting of a nozzle touch member with the tip of the shaft formed as a threaded shaft, and a screw receiving member provided below the fixed plate of the mold clamping device, the lower side of the injection device that moves the nozzle touch member relative to the fixed plate. The screw shaft is provided horizontally and rotatably on the fixed platen, and the screw shaft protrudes toward the fixed platen, and is screwed into the screw receiving member so as to be able to move forward and backward to connect the injection device to the fixed platen, and the shaft portion is rotated by an electric motor. A nozzle touch device for an electric injection molding machine, which is connected to a transmission shaft.