JPS6347467Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a drive control device for an electric injection molding machine.

(b) Conventional technology There is an electric injection molding machine that uses electric power to perform a series of molding processes such as mold clamping and injection, but conventional electric injection molding machines use a single servo motor as the drive source. A series of molding processes is realized by using a large number of electromagnetic clutches, electromagnetic brakes, etc., and switching their operations.

(c) Problems to be solved by the invention However, since conventional electric injection molding machines such as those mentioned above use a large number of electromagnetic clutches, electromagnetic brakes, etc., their durability and reliability are insufficient. Otherwise, there was a problem that the injection molding machine could not have sufficient performance. Therefore, by reducing the number of electromagnetic clutches, electromagnetic brakes, etc., and using multiple servo motors,
There is a method in which each servo motor individually realizes the operation of the molding process. But in this case,
In order to drive and control a plurality of servo motors, a servo driver amplifier amplifier is required for each, resulting in a very high price and a large control device, requiring a large installation space.
The present invention aims to solve the above-mentioned problems.

(d) Means for solving the problems The present invention achieves the above object by driving and controlling a plurality of servo motors using one servo driver amplifier. That is, the drive control device for an electric injection molding machine according to the present invention includes one servo driver amplifier amplifier that has the ability to drive and control the largest capacity of a plurality of servo motors, and a plurality of servo driver amplifier amplifiers. A controller that outputs control signals that command each operation of the molding process such as mold clamping and injection based on a plurality of power lines that are respectively connected to the servo motors and signals indicating the operating status of each servo motor. The servo driver amplifier has a conductive wire for inputting a control signal output from the controller to the servo driver amplifier.

(E) Function The controller controls mold closing, mold clamping, injection, holding pressure, plasticization, mold opening, and molded products by using signals indicating the operating state of the servo motor from a current detector, pulse generator, etc. as a control element. A control signal is output so that a series of ejection forming operations are performed sequentially. The servo driver amplifier outputs a current to operate a predetermined servo motor through a power line based on a control signal from a controller. This realizes a predetermined molding process. Since only one servo driver amplifier is required, the cost is reduced and the space required is also reduced.

(F) Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 4 of the accompanying drawings.

Figures 2 and 3 show an example of an electric mold clamping device.

A fixed platen 12 and an end housing 14 are fixed onto the bed 10 by bolts 16 and 18, respectively. The fixed platen 12 and the end housing 14 are arranged in parallel so as to face each other with a predetermined spacing therebetween. Four tie bars 20 for fixed platen 12 and end housing 14
is rotatably supported. The tie bar 20 is
As shown in FIG. 3, they are arranged at each corner of the fixed platen 12 and the end housing 14 (that is, they are arranged at each vertex of a square). The tie bar 20 connects the bearing 22 to the fixed plate 12.
The tie bar 20 is rotatably supported by the tie bar 20.
The vertical force acting in the left direction in FIG. 2 is supported by a thrust bearing 24. The thrust bearing 24 is connected to the fixed plate 12,
Nut 2 screwed into the screw at the end of tie bar 20
It is located between 6 and 6. Note that the nut 26 is prevented from loosening by a lock nut 28.
The other end of the tie bar 20 is connected to the end housing 1
4 by a bearing 30 so as to be rotatable. Bearing 30 is held to end housing 14 by metal fittings 32. A male thread 34 of a ball screw mechanism is formed on the outer periphery of the tie bar 20. Each male thread 34 has
A nut member 36 having an internal thread constituting a ball screw mechanism is engaged with the nut member 36. Four nut members 36 are fixed to a movable platen 38. Movable plate 38
has a hole 38a through which the tie bar 20 passes, and is movable in the axial direction of the tie bar 20 by rotating the male screw 34. A movable mold 40 is attached to this movable plate 38, while a fixed plate 1
A fixed mold 42 is attached to 2. A servo motor 4 for mold clamping is installed in the center of the end housing 14.
4 is installed. The servo motor 44 includes an electromagnetic brake 46, a torque sensor 48, and a pulse generator 50. The rotational force of the servo motor 44 is transmitted to the tie bar 20 by a drive mechanism 56 composed of a drive gear 52 and four driven gears 54. That is, a drive gear 52 is attached to the rotating shaft 44a of the servo motor 44 by a key 58, and the tie bar 2
Driven gear 5 by key 60 respectively for 0
4 is installed. The driving gear 52 meshes with four driven gears 54 at the same time.

FIG. 4 shows an example of an electric injection device.

A screw 112 is inserted into the cylinder 110. A casing 114 is attached to the rear end side of the cylinder 110 (upstream side in the resin flow direction). The casing 114 includes a housing 116 and a cover 118, which define a chamber 120. Within this chamber 120 is a rotatable and axially movable intermediate shaft 122.
is provided. The intermediate shaft 122 is the small diameter shaft portion 12
4 and a large diameter shaft portion 126. Small diameter shaft part 1
The tip of 24 is attached to the screw 11 by a spline.
It is connected to 2. The small diameter shaft portion 124 has sliding bearings 136 and 1 attached to the housing 116.
38 so as to be rotatable and axially movable. A nut member 154 having a female thread that constitutes a ball screw mechanism 152 together with a male thread 150 provided on the shaft 148 is fixed to the large diameter shaft portion 126 side of the intermediate shaft 122 . Male thread 15
A shaft 148 provided with a thrust bearing 156 and a bearing 158 with respect to the cover 118
is rotatably supported by. The shaft 148 is connected to a servo motor 170 outside the casing 114 for moving the screw in the axial direction. The servo motor 170 is provided with a pulse generator 172. A driven gear 182 is attached to the outer periphery of the large diameter shaft portion 126 of the intermediate shaft 122 by a key 181 so as to rotate together with the intermediate shaft 122 . The driven gear 182 is a driving gear 183 with a collar 183a.
This drive gear 183 is engaged with the shaft 1.
84 by a sliding key 185. The shaft 184 connects the housing 116 and the cover 1
18 by bearings 186 and 187 so as to be rotatable. A portion of the shaft 184 that protrudes outside the casing 114 is connected to a servo motor 171 for driving the rotation of the screw.
The servo motor 171 is provided with a pulse generator 173.

FIG. 1 shows a drive control device for an electric injection molding machine. This drive control device includes a controller 201 and a servo driver amplifier amplifier 203. The servo driver amplifier amplifier 203 is
It is connected to servo motors 44, 170 and 171 via power lines 205, 207 and 209, respectively. Power lines 205, 207 and 209 are provided with current detectors 211, 213 and 215, respectively, which are connected to conductors 217 and 209, respectively.
It is connected to the controller 201 by 219 and 221. Further, pulse generators 5 provided in the servo motors 44, 170 and 171, respectively.
0, 172 and 173 are also conductors 223 and 2, respectively.
It is connected to the controller 201 by 25 and 227. The controller 201 includes a mold clamping device controller 201a that controls mold opening/closing, mold clamping, etc., and an injection device controller 201b that controls injection speed, screw rotation speed, etc. Controller 201 outputs a predetermined control signal using signals from current detectors 211, 213 and 215 and pulse generators 50, 172 and 173. Control signal is lead 2
Servo driver amplifier amplifier 20 by 29
3 is input. Servo driver amplifier fire 203 outputs a predetermined current to one of servo motors 44, 170, and 171 based on a control signal from controller 201. Note that the servo driver amplifier amplifier 203 has the ability to output the maximum input current to the servo motor 170, which has the largest capacity. Further, the servo driver amplifier amplifier 203 is connected to the controller 201.
Power lines 205, 207 based on control signals from
and 209, it has a built-in switching circuit that switches to output current to a predetermined one.

Next, the operation of this embodiment will be explained. First, the mold is closed. That is, the controller 201 supplies a predetermined current from the servo driver amplifier amplifier 203 to the servo motor 44 through the power line 205, rotates the servo motor 44 in a predetermined direction, rotates the tie bar 20 via the drive mechanism 56, The movable platen 38 is moved by the action of the male screw 34 and the nut member 36. This allows fixed type 4
The mold closing step is completed by bringing the movable mold 40 into close contact with the mold 2, and then mold clamping is performed. That is, the servo motor 44 is rotated until the torque value detected by the torque sensor 48 reaches a predetermined value, and when the torque value reaches the predetermined value, the electromagnetic brake 46 is activated. As a result, mold clamping is completed and a predetermined mold clamping force is applied between the fixed mold 42 and the movable mold 40. Injection then takes place. That is, the controller 2 causes the servo motor 170 of the injection device to rotate when the plasticizing stroke has been completed.
01 outputs a control signal. Based on this, the servo driver amplifier amplifier 203 connects the power line 20
A predetermined current is supplied to the servo motor 170 via 7. At this time, the servo motor 171 remains stopped. The intermediate shaft 122 and the nut member 154 integrated therewith are connected to the driven gear 182 and the driving gear 1.
Since it is connected to the servo motor 171 via the shaft 183 and the shaft 184, it cannot rotate. Therefore, when the male thread 150 of the shaft 148 is rotated by the servo motor 170, the ball screw mechanism 1
52 causes the nut member 154 to move to the left in FIG. For this reason, the nut member 15
4. The intermediate shaft 122 and the screw 112 connected thereto move to the left in FIG. As a result, the resin that has been plasticized and melted within the cylinder 110 is injected. The driving gear 183 is the driven gear 182
It also moves following the intermediate shaft 122. When the injection stroke is completed in this way, pressure holding is performed for a predetermined period of time. When the pulse generator 172 detects that the injection stroke is complete, the controller 2
01 stops the current supply to the servo motor 170 and puts the servo motor 170 in a free rotation state.
On the other hand, the servo motor 171 is connected via the power line 209.
A predetermined current is supplied to the When the shaft 184 is rotated by the servo motor 171, the intermediate shaft 122 is rotated via the driving gear 183 and the driven gear 182. When the intermediate shaft 122 rotates, the screw 112 connected to the intermediate shaft through a spline rotates within the cylinder 110, melting and plasticizing the resin material supplied to the inner diameter of the cylinder 110 from the material supply port 110a. Transfer it forward (to the left in Figure 4). As the molten resin transferred to the front of the cylinder 110 increases, the screw 11
2 moves backward while rotating (moves to the right in Fig. 4). Therefore, the intermediate shaft 122 similarly moves to the right in FIG. 4. Since the shaft 148 is connected to the intermediate shaft 122 by a ball screw mechanism 152, it rotates at a certain rotational speed as the intermediate shaft 122 rotates, but it rotates at a rotational speed higher than the rotational speed of the intermediate shaft 122. Never. Therefore, the nut member 154 rotates relative to the external thread 150 and moves to the right in FIG. As the intermediate shaft 122 moves, the driving gear 183 moves along the sliding key 185 to the intermediate shaft 122 while being engaged with the driven gear 182 due to the action of the collar 183a.
Move by following. In this way, when the intermediate shaft 122 and the screw 112 move by a predetermined stroke, the supply of current to the servo motor 171 is stopped, and the plasticizing stroke is completed. Next, the mold is opened. That is, when current is again supplied from the power line 205 to the servo motor 44 and the drive gear 52 is rotated in the opposite direction to that in the above case, the four driven gears 54 meshing therewith rotate in a synchronized state. Therefore, the movable platen 38 is moved to the left in FIG. 2 by the action of the nut member 36 that engages with the external thread 34 of the tie bar 20. Movement of the movable platen 38 is detected by the pulse generator 50, and when the movable platen 38 reaches a predetermined position, the controller 201 stops the servo motor 44. At the same time, electromagnetic brake 4
Activate 6. This completes the mold opening, and the molded product is taken out from the mold. This completes one molding cycle, and the same molding cycle as described above is repeated again. Although there are three servo motors in this embodiment, it is clear that the present invention is equally applicable even when two or four or more servo motors are used.

(G) Effect of the device As explained above, according to the present device,
Since multiple servo motors are controlled by one servo driver amplifier,
Compared with the case where a servo driver amplifier is provided for each servo motor, the cost can be reduced, the drive control device can be made smaller, and the installation space can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a drive control device for an electric injection molding machine according to the present invention, FIG. 2 is a diagram showing an electric mold clamping device, FIG. 3 is a sectional view taken along the - line in FIG. 2, and FIG. FIG. 2 is a diagram showing an electric injection device. 44,170,171...Servo motor, 20
1...Controller, 203...Servo driver amplifier fire, 205, 207, 209...Power line, 229...Conducting wire.

Claims (1)

[Scope of Claim for Utility Model Registration] In a drive control device for an electric injection molding machine in which each operation of the molding process such as mold clamping and injection is performed using multiple servo motors, the one with the largest capacity among the multiple servo motors. Based on a single servo driver amplifier that has the ability to drive and control multiple servo motors, multiple power lines that connect the servo driver amplifier to multiple servo motors, and signals that indicate the operating status of each servo motor. A controller that outputs control signals for commanding each operation of the molding process such as mold clamping and injection, and a conductor that inputs the control signals output from the controller to the servo driver amplifier. Drive control device for electric injection molding machines.