JPH042031Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an electric injection molding machine.

Conventional Technology In the past, injection molding machines were mainly driven by hydraulic pressure, and it was difficult to repair and maintain hydraulic equipment, such as taking measures against oil leaks and controlling oil temperature.

In addition, some small models have recently begun to be electric, but their capacity remains small, and these machines use a single electric servo motor for the injection and metering processes. A separate brake device is required for back pressure adjustment.

Problems to be Solved by the Invention The present invention was devised in view of the above circumstances, and its purpose is to simultaneously operate the injection back pressure servo motor and the injection metering servo motor during the injection process, and to During the process, the injection metering servo motor can be used to measure and the injection back pressure servo motor can be used to adjust the back pressure, which not only makes effective use of the servo motor, but also eliminates the need for a separate brake device to adjust the back pressure. Our purpose is to provide injection molding machines.

Means and Effects for Solving the Problems The present invention includes an injection mechanism A that advances the injection screw 10 by screwing the screw 21 through rotation of the nut member 20, a metering mechanism B that rotates the injection screw 10, an injection metering servo connected to a rotation imparting portion of the nut member of the injection mechanism A via a first power transmission mechanism C, and connected to a rotation imparting portion of the injection screw of the metering mechanism B via a second power transmission mechanism D; A motor 28, an injection back pressure servo motor 29 connected to the rotation imparting portion of the nut member 20 of the injection mechanism A via a third power transmission mechanism E, and an injection back pressure servo motor 29 provided in the first power transmission mechanism C to perform the injection process. The injection clutch 35 is configured to be actuated at the time of the injection process, and the metering clutch 34 is provided in the second power transmission mechanism D and is actuated at the time of the metering process. 35, the power of the injection metering servo motor 28 is transmitted to the injection mechanism A through the first transmission mechanism C, and the power of the injection back pressure servo motor 29 is transmitted through the third power transmission mechanism E. The power of the injection metering servo motor 28 is transmitted to the injection mechanism A, and the power of the injection metering servo motor 28 is transferred to the second injection metering servo motor 28 by engaging and operating the metering clutch 34 during the metering process.
The power of the injection backpressure servo motor 29 is transmitted to the metering mechanism B via the power transmission mechanism D of the third
The power is transmitted to the injection mechanism A via the power transmission mechanism E to adjust the back pressure.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is an injection mechanism, and 2 is a mold clamping mechanism.

The injection mechanism 1 includes a device main body 3, and a holder 5 is provided on the device main body 3 via a bearing 4.
A gear 6 is fixed to the holder 5. A shaft 7 is provided on the holder 5 so as to be movable back and forth. A key 8 provided on the shaft 7 is inserted into a keyway 9 of the holder 5. An injection screw 10 is attached to the tip of the shaft 7, and the injection screw 10 is inserted into an injection tube 11 provided in the device main body 3. A nozzle 12 is provided at the tip of the injection tube 11. be. Band heaters 13 and 14 are attached to the periphery of the nozzle 12 and the injection tube 11. A hopper 16 is connected to the inlet portion 15 at the base of the injection tube 11, and these constitute a metering mechanism B.

Also, a gear 1 is connected to the device main body 3 via a bearing 17.
A nut member 20 is attached to the inside of the gear 18, and a screw 21 is screwed into the nut member 20. A spline portion 22 is provided at the rear end of the screw 21.
2 is slidably fitted into a spline receiver 23 provided on the main body 3 of the device. A support shaft 25 is provided at the front end of the screw 21 via a pressure sensor 24.
The support shaft 25 is connected to the rear end of the shaft 7 via a bearing 26, and constitutes an injection mechanism A.

The apparatus main body 3 is provided with an injection metering servo motor 28 and an injection back pressure servo motor 29.

Further, the device main body 3 is provided with rotation support shafts 30, 31 and a support shaft 32, and a second gear 32' and a third gear 33 are rotatably provided on the rotation support shaft 30.
Further, the rotation support shaft 30 is provided with a metering clutch 34 and an injection clutch 35.
The movable side of the injection clutch 3 is connected to the second gear 32'.
The movable sides of the gears 5 are connected to the third gear 33, respectively. A first gear 36 is fixed to the rotation support shaft 30, and the first gear 36 is connected to the injection metering servo motor 28.
The pinion 37 is engaged with the pinion 37.

Fourth and fifth gears 38 and 39 are integrally and rotatably provided on the support shaft 32, a pinion of an injection back pressure servo motor 29 is meshed with the fourth gear 38, and a fifth gear The third gear 33 meshes with the gear 39.

The rotation support shaft 31 has sixth and seventh gears 40 and 4.
No. 1 is fixed to the rotary support shaft 31, and No. 8 and No. 9 are fixed to the rotation support shaft 31.
Gears 42 and 43 are integrally provided so as to be rotatable. The sixth gear 40 meshes with the gear 6, the second gear 32' meshes with the seventh gear 41, the fifth gear 39 meshes with the eighth gear 42, and the ninth gear 43 meshes with the seventh gear 41. It meshes with gear 18.

The mold clamping mechanism 2 includes a device main body 44,
A nut member 4 is connected to the device main body 44 via a bearing 45.
6 is provided, and a screw 47 is provided on the nut member 46.
are screwed together, and a movable die plate 49 is connected to the screw 47 via a mold clamping toggle link 48. 50 is a fixed die plate, a mold 51 is attached to the movable die plate 49, and a die 52 is attached to the fixed die plate 50, respectively.

A mold clamping servo motor 53 is attached to the device main body 44, and a gear 5 is attached to the nut member 46.
4 is attached, and a pinion 55 of a mold clamping servo motor 53 meshes with a gear 54 via a gear train 56.

The movable die plate 49 is provided with a molded product ejection mechanism 57.

The device main body 3 of the injection mechanism 1 is provided with a metering brake 58 that is opened only during metering.

Next, the operation will be explained.

(1) Injection process During injection, the third gear 33 is fixed to the rotating shaft 30 by connecting the injection clutch 35.

The output of the injection metering servo motor 28 is a pinion 37, a first gear 36, a rotating shaft 30, and a third gear 3.
3. The power is input to the gear 18 via the fifth gear 39, the eighth and ninth gears 42 and 43, that is, the first power transmission mechanism C.

Further, the output of the injection back pressure servo motor 29 is input to the gear 18 via the pinion, the fourth and fifth gears 38 and 39, the eighth and ninth gears 42 and 43, ie, the third power transmission mechanism E.

The nut member 20 is rotated by the rotation of the gear 18, and the screw 21 is moved forward or backward by screw feeding. During the injection process, the forward movement of the screw 21 is utilized, and this forward movement of the screw 21 is caused by the shaft 7.
The injection screw 10 is advanced to perform injection.

Injection speed control during the injection process is performed by controlling the rotation speed using a tacho generator of the injection back pressure servo motor 29.

Further, the position control of the injection screw 10 is performed by checking the operating position using the encoder of the injection back pressure servo motor 29.

Furthermore, injection back pressure servo motor 29 controls injection pressure.
Torque control is performed by controlling current with a servo amplifier.

(2) Measuring process The metering clutch 34 is connected to fix the second gear 32' to the rotating support shaft 30, and the metering brake 58 is released.

The output of the injection metering servo motor 28 is the pinion 3
7, first gear 36, second gear 32', seventh gear 4
1. Sixth gear 40, that is, second power transmission mechanism D
is input to gear 6 via. For this purpose, the holder 5 rotates and the injection screw 1 is inserted through the shaft 7.
0 rotates and weighing is performed.

During metering, it is necessary to apply back pressure to the injection screw 10.

The back pressure is applied by driving the injection back pressure servo motor 29 to rotate the gear 18 to advance the screw 21 and apply pressure to the injection screw 10 via the shaft 7. The back pressure can be set to an arbitrary value by controlling the torque of the injection back pressure servo motor 29.

(3) Mold clamping process The mold clamping servo motor 53 is driven, and the gear train 56
The gear 54 is rotated through the nut member 46 to advance the screw 47, the movable die plate 49 is advanced through the mold clamping toggle link 48, and the mold 51 is inserted into the mold 52. conduct.

The mold clamping position is determined by directly reading the movement of the movable die plate 49 using a linear scale and controlling the mold clamping servo motor 53 in a feedback manner. Therefore, the pressing force of the mold is weakened slightly before the mold closes, and the mold 5 is removed.
A low-pressure mold protection function for protecting the parts 1 and 52 from being caught by foreign matter can also be performed by controlling the torque of the mold clamping servo motor 53.

As shown in FIGS. 2 to 4, the molded product ejecting mechanism 57 includes a camshaft 60 rotatably provided on the movable die plate 49, and the camshaft 60 is connected to a worm reducer 62 via a coupling ring 61. The worm reducer 62 is connected to the output shaft 63 of the
The input side of is connected to a motor 64. camshaft 6
A cam 65 is attached to 0.

A plurality of pin holes 66 are provided in the movable die plate 49, and knockout pins 67 are inserted into the pin holes 66.
is inserted, the knockout pin 67 is connected to a connecting member 68, a cam follower 69 is provided on this connecting member 68, the connecting member 68 is urged toward the cam 65 by a spring 70, and the cam follower 69 is attached to the connecting member 68. 69 circumscribes the cam 65.

The movable die plate 49 is provided with forward and backward proximity switches 71 and 72 via a support member 70', and the connecting member 68 is provided with a dog 73.

By driving the motor 64, the camshaft 60 is rotated via the worm reducer 62, the cam 65 is rotated, the cam follower 69 is pushed, the knockout pin 67 is moved, and the molding inside the mold 51 is performed. Stick out the item.

When the knockout pin 67 is pulled back, the motor 64 is reversed, the cam 65 is reversed, and the spring 70 is used.

The rotation of the cam 65 is controlled by proximity switches 72 and 73 at forward and backward ends, and is performed in both forward and reverse directions.
By adjusting the positions of the proximity switches 72 and 73, the forward and backward ends of the knockout pin 67 are adjusted.

Furthermore, the mold clamping force may be set automatically.

The mold clamping servo motor 53 is provided with an encoder 74, and the encoder output is connected to a control computer 75. The control computer 75 controls the mold clamping servo motor 53 by controlling a motor drive servo amplifier 76. control indirectly.

The mold clamping toggle link 48 has a stroke on the drive side and a stroke on the output side as shown in FIG. 6, which are not straight lines.

Therefore, this relationship is stored in the control computer 75 so that the stroke of the movable die plate 49 required for each set mold clamping force is converted into the mold clamping toggle link driving stroke. This command is used to issue a command to the servo amplifier 76. At this time, the set mold clamping force can be accurately displayed on the display device 77 by the control computer 75.

Furthermore, the mold thickness adjustment may be changed from a conventional hydraulic device to an electric device.

That is, the motor 80 is connected to a torque limiter 81, and the power of the motor 80 moves the movable die plate 49 through the torque limiter 81.
A potentiometer 82 is attached to the movable die plate 49.
are directly connected to each other, and the potentiometer 82 outputs a changing potential in accordance with the movement of the moving die plate 49. This output is sent to the motor control computer 83.
will be processed.

When the movable die plate 49 moves and the molds 51 and 52 come into close contact with each other, the torque limiter 81 slips and cuts off the transmission of the motor power.
2 cannot be held down with more than a certain force. The motor control computer 83 monitors the movement of the potentiometer 82, and stops the motor 80 if there is no change in the potentiometer 82 for a certain period of time even though the motor 80 is moving.

The potentiometer position is also processed by the motor control computer 83 so that the position of the mobile diver 84 can be displayed by the display device 85.
The position of the mobile diver 84 can also be controlled.

In this way, the injection molding machine's mold thickness adjustment device has been changed from hydraulic to electric, eliminating oil leaks.

Effects of the invention Since the invention is as described above, the power of the injection metering servo motor 28 is transferred to the first transmission mechanism C by engaging and operating the injection clutch 35 during the injection process.
At the same time, the power of the injection backpressure servo motor 29 is transmitted to the injection mechanism A through the third power transmission mechanism E, and during the metering process, the metering clutch 37 is engaged and operated to cause injection. The power of the metering servo motor 28 is transferred to the second power transmission mechanism D.
The back pressure can be adjusted by transmitting the power of the injection back pressure servo motor 29 to the injection mechanism A through the third power transmission mechanism E.

In this way, the injection back pressure servo motor 29 and the injection metering servo motor 28 are operated simultaneously during the injection process, and the injection metering servo motor 28 is operated during the metering process.
The injection back pressure servo motor 29 can perform metering and back pressure adjustment using the injection back pressure servo motor 29, making effective use of the servo motor possible. This eliminates the need for a separate brake device for adjusting the back pressure.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the configuration of one embodiment of the present invention, Fig. 2 is a front view of the molding and ejecting device, and Fig. 3 is Fig. 2-
Figure 4 is a cross-sectional view taken along the line from Figure 3, Figure 5 is an explanatory diagram of the structure of the automatic mold clamping force setting device, Figure 6 is a stroke diagram, and Figure 7 is a mold thickness adjustment. FIG. 3 is an explanatory diagram of the structure of the mechanism. 28 is an injection metering servo motor, 29 is an injection back pressure servo motor, 34 is a metering clutch, and 35 is an injection clutch.

Claims (1)

[Scope of utility model registration request] An injection mechanism A that advances the injection screw 10 by screwing the screw 21 by rotation of the nut member 20, a metering mechanism B that rotates the injection screw 10, and a first The injection metering servo motor 28 is connected to the injection screw rotation imparting portion of the metering mechanism B via the second power transmission mechanism D, and the nut member 20 of the injection mechanism A is rotated. An injection back pressure servo motor 29 connected to the application portion via a third power transmission mechanism E, an injection clutch 35 provided in the first power transmission mechanism C and activated during the injection process, and a third power transmission mechanism E. 2. An injection molding machine characterized by comprising a metering clutch 34 provided in the power transmission mechanism D of No. 2 and actuated during the metering process.