JPH0423615B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to injection molded products (hereinafter referred to as molded products).
This invention relates to an automatic take-out device.

(b) Prior Art In order to reduce the cost of the device, a conventional automatic take-out device uses a capacitor running type induction motor as a drive source for the traveling body or the front and rear traveling bodies. Then, in order to position the chuck part that chucks the molded product at a predetermined molded product take-out position and release position with high positional accuracy, the running body or the front and rear running bodies are pressed against the docks attached to these take-out positions and release positions. The positioning accuracy of the part was obtained. In addition, in order to obtain high positioning accuracy at these positions, a DC servo motor was used as the drive source, and this was numerically controlled.

(c) Problems to be Solved by the Invention However, in the above-mentioned conventional molded product automatic removal device, the device, especially the chuck portion, vibrates due to the collision between the dock and the traveling body or the front and rear traveling bodies, causing molding. This has led to problems such as poor checking of the product.

In addition, the impact during the pressing process causes a decrease in mechanical strength, resulting in a problem that the durability of the device deteriorates. These drawbacks can be solved by using a numerically controllable servo motor or the like as a drive source, but the device has the drawback of increasing cost.

(d) Means for Solving the Problems In view of the above-mentioned conventional drawbacks, the object of the present invention is to use a low-cost capacitor running type induction motor as a drive source, and to reduce the electric power supplied to this induction motor. An object of the present invention is to provide an automatic take-out device for injection molded products, which has high accuracy in positioning the chuck part at the take-out position and release position by digitally controlling the chuck part.

The present invention also provides a traveling body that is supported so as to be reciprocally movable between an extraction position and a release position of the injection molded product, a front-rear traveling body that is supported by this traveling body so that it can be reciprocated in the front and back direction, In an automatic take-out device which is mounted to be movable in the vertical direction by a vertically operating member attached to the front and rear traveling body and which takes out injection molded products using a chuck portion, either or both of the said traveling body and the front and rear travel bodies are provided. an induction motor connected for driving and a capacitor connected to a main coil and an auxiliary coil respectively connected in parallel, first and second bidirectional switching elements for circulating AC power, a traveling body and a front and rear traveling body. an alternating current generator that outputs a detection signal with a voltage level corresponding to the moving speed of one or both of the following: a counter circuit that stores the actual distance traveled by the driven object based on the voltage level of the number of input detection signals; a memory in which speed data corresponding to the running pattern of either or both of the body and the front and rear running bodies is stored in advance; PID calculation of the flow angle of the first or second bidirectional switching element is performed based on the voltage level of the set speed signal converted into an analog signal and the detection signal, and the induction motor can be rotated reversibly and at variable speed. It consists of a control device that controls the

(e) Effects of the Invention According to the present invention, a low-cost capacitor running type induction motor is used as the drive source of the drive system that reciprocates the chuck portion in the axial direction of the screw shaft or in the direction orthogonal to the axis of the screw shaft. The induction motor is controlled based on the voltage level of the detection signal corresponding to the actual moving speed of the traveling body and/or the front and rear traveling bodies, and the set speed signal accessed from the memory and converted into an analog signal. The flow angle of the first or second bidirectional switching element is calculated by PID using digital control, and the amount of electric power supplied to the induction motor is varied. By performing speed control and position control, it is possible to stop either or both of the traveling body and the front and rear traveling bodies at a take-out position or a release position with high positioning accuracy.

(f) Effects of the Invention Since the automatic molded product retrieval device of the present invention uses a low-cost capacitor running type induction motor as a drive source, the drive of either or both of the traveling body and the front and rear traveling bodies is unnecessary. In addition to reducing the cost of the system, the amount of power supplied to the induction motor is calculated by PID using the voltage level of the detection signal and the set speed signal accessed from the memory and converted to an analog signal. Either one or both of the front and rear traveling bodies are driven reversibly at variable speeds, and the positioning accuracy of the chuck portion at the molded product take-out position and the release position is highly accurate.

(g) Examples Examples will be described below with reference to the drawings.

1 to 3, a running frame 2 of an automatic take-out device 15 is fixed to an injection molding machine 1. As shown in FIGS. The running frame 2 is elongated in a direction perpendicular to the axis of an injection screw (not shown) in the injection molding machine 1, and has a running rail 3 fixed to its upper surface in the longitudinal direction. Furthermore, a rack gear 4 is fixed to the running frame 2 along its longitudinal direction. A running body 5 is supported on the running rail 3 so as to be able to reciprocate in left and right directions perpendicular to the axis of the injection screw. This running body 5
is a capacitor running type induction motor 6.
is placed thereon, and a pinion gear (not shown) that meshes with the rack gear 4 is attached to its rotating shaft. Further, front and rear frames 7 are integrally attached to the traveling body 5, and front and rear rails 8 are fixed to the front and rear frames 7. This front and rear rail 8
supports a front-rear traveling body 9 that can reciprocate back and forth in the same direction as the axis of the screw shaft. A front and rear cylinder 10 is fixed to this front and rear traveling body 9, and an operating end of this front and rear cylinder 10 is fixed to the front and rear frame 7. As a result, the front and rear traveling bodies 9 are reciprocated in the same direction as the axis of the injection screw as the front and rear cylinders 10 operate.

A vertical cylinder 11 is fixed to the front and rear traveling body 9 in a direction perpendicular to the axis of the screw shaft, and a chuck holder 1 is attached to the operating end of the vertical cylinder 11.
2 is fixed. Incidentally, a pair of guide rods inserted through the fore-and-aft traveling body 9 are fixed to the chuck holder 12.

A chuck plate 13 is detachably attached to the chuck holder 12, and at least a pair of chuck cylinders 14 for chucking a runner or sprue (none of which is shown) of a molded product is fixed to the chuck plate 13. There is.

The induction motor 6 is driven and controlled as follows.

4 and 5A and B, the main coil 20 and the auxiliary coil 21 of the induction motor 6
One terminal of the AC power supply is commonly connected to one terminal of the AC power supply. Further, a capacitor 22 is connected in parallel to the other end of the main coil 20 and the auxiliary coil 21, and is connected to one electrode of a first and second bidirectional switching element 23, 24, such as a triac (trade name), respectively. It is connected. These first and second
The other terminal of the alternating current power supply AC is commonly connected to the other electrode of the two-way switching elements 23 and 24. And these first and second bidirectional switching elements 2
Between the electrodes 3 and 24, there is a power frequency detection device 16,
17 are connected to each other.

A driven body (none of which is shown) is drivingly connected to the rotating shaft of the induction motor 6 via a suitable speed reducer as necessary. Further, a tacho generator 25 as an alternating current generator is attached to the rotating shaft. This tacho generator 25 outputs a detection signal of a voltage level corresponding to the rotational speed of the rotating shaft. After this detection signal is rectified into a DC voltage by the rectifier 26, it is used as a speed control signal, which will be described later. Further, the rectified detection signal is waveform-shaped into a rectangular wave by the waveform shaping circuit 27, and then
It is input to the counter circuit 28. This counter circuit 28 stores the actual distance traveled by the driven object by sequentially varying the voltage according to the input detection signal. Further, this counter circuit 28 is connected to a setting device 29.
The voltage level is set according to the set distance of the driven object. As a result, the counter circuit 28 stores the set distance of the driven object. The count signal, which has a voltage level corresponding to the number of detected signals, is converted by the A/D conversion circuit 30 into a digital signal corresponding to the voltage level, and then output to the memory control device 31. Based on this digital signal, the memory control device 31 stores speed data in the memory 3 in accordance with the actual travel distance and travel pattern of the driven object.
Access from 2. This memory 32 stores in advance various speed data corresponding to the traveling distance and traveling pattern (accelerating traveling, constant speed traveling, decelerating traveling) of the driven body. The area in this memory 32 in which various speed data related to deceleration traveling are written is called a slowdown table. This speed data is converted by the D/A conversion circuit 33 into a set speed signal having a voltage level corresponding to the speed data.

Then, the control device 40 determines a PID constant (P is a proportional constant, I is an integral constant, and D is a differential constant) based on the voltage level of the detection signal of the actual moving speed of the driven object and the set speed signal, and For phase excitation, the application time of the gate current that determines the flow angle of the first bidirectional switching element 23 is calculated by PID. The control device 40 detects a zero cross nπ (n is an arbitrary integer) of the AC power frequency based on the frequency detection signals from the power frequency detection devices 16 and 17, and detects the next zero cross { The gate current up to (n+1)・π} is the first
The first bidirectional switching element 23 is outputted to the bidirectional switching element 23, and the first bidirectional switching element 23 is made to flow. At this time, since the speed data is set to a high potential according to the voltage level of the detection signal when the driven object is running at an accelerated speed, the control device 40 controls both of the first and second sides as shown in FIGS. 2A and 3B. Large electric power is supplied to the main coil 20 and the auxiliary coil 21 by circulating the directional switching element 23 at a large flow angle. On the other hand, when the driven body is running at a constant speed, the voltage level of the detection signal is set to be approximately equal to the speed data, so the control device 40
supplies small electric power to the main coil 20 and the auxiliary coil 21 by causing the first bidirectional switching element 23 to flow at a small flow angle. Through these operations, the control device 40 controls the induction motor 6.
The amount of power supplied to the motor is varied to control the speed of the driven object.

Then, along with the above-mentioned constant speed running, the counter circuit 28
When the voltage level of the driven body reaches the voltage level corresponding to the slowdown start position a of the driven body, the control device 40
After switching the memory 32 to the slow-down table, the data is accessed from the slow-down table in accordance with the voltage level of the detection signal and the actual moving distance of the driven object, and converted by the D/A conversion circuit 33 in the same way as in the above-mentioned operation. PID calculation is performed using a PID constant according to the voltage level of the set speed signal. At this time, immediately after the start of slowdown, the speed data stored in the slowdown table is set to a lower speed than the actual moving speed of the driven object, so the controller 40
If the above PID calculation result exceeds a predetermined negative value, the second bidirectional switching element 24 is caused to flow, thereby causing reverse phase excitation. As a result, the driven body is decelerated and moved at a low speed. Incidentally, when the actual moving speed of the driven object reaches a predetermined low speed, the control device 40 causes the first bidirectional switching element 23 to flow in a half-wave, so as to slowly feed the driven object from just before the target position b. It is also possible to use a method in which the

When the count signal of the counter circuit 28 reaches the set voltage level corresponding to the set distance according to the actual moving distance of the driven body due to the above-mentioned low-speed movement, the control device 40 controls the first bidirectional switching element 23. The flow is interrupted and the driven body is stopped at the target position b. If the detection signal is not input for a predetermined period of time, the control device 40 determines that the driven body has been stopped. The above explanation mainly focuses on the first bidirectional switching element 2.
Although we have described the operation of moving the driven body forward by circulating the second bidirectional switching element 24, the same applies to the case where the driven body is moved backward by circulating the second bidirectional switching element 24. , a detailed explanation thereof will be omitted.

Further, the electronic control device 40 is configured so that the driven body is at the target position b.
If the detection signal is not input for a predetermined period of time when the vehicle is not being driven, it is determined that an overload is acting on the driven body, and the first or second bidirectional switching elements 23 and 24 are switched off. Discontinue distribution. This prevents the main coil 20 and the auxiliary coil 21 from burning out.

In this embodiment, one or both of the traveling body and the front and rear traveling bodies were set to the traveling pattern shown in FIG. By rewriting or replacing the memory in accordance with the displayed running pattern, it is possible to drive and control either or both of the running body and the front and rear running bodies in a running pattern that allows high positioning to the target position. In this case, the inertial force of either or both of the running body and the front and rear running bodies is reduced to zero by temporarily stopping either or both of the running body and the front and rear running bodies before the target position, and then the running body and the front and rear running bodies are stopped. Since one or both of the bodies is fed at a very slow speed, high positioning accuracy is achieved for either or both of the traveling body and the front and rear traveling bodies with respect to the target position.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the outline of the automatic molded product removal device, Fig. 2 is a schematic perspective view showing the front and rear running sections, and Fig. 3
4 is an electronic block diagram, FIG. 5A is a diagram showing a running pattern, B is a current waveform diagram, and FIGS. 6 and 7 are a running diagram of the present invention. It is a diagram showing an example of changing a pattern. In the figure, 1 is an injection molding machine, 5 is a traveling body, 6 is an induction motor, 9 is a front and rear traveling body, 11 is a vertical cylinder as a vertical operating member, 14 is a chuck cylinder that constitutes a chuck part, and 15 is an automatic ejector. 20 is a main coil, 21 is an auxiliary coil, 22 is a capacitor, 23 is a first bidirectional switching element, 2
4 is a second bidirectional switching element, 28 is a counter circuit, 32 is a memory, 40 is a control device, and AC is an alternating current power source.

Claims (1)

[Scope of Claims] 1. A traveling body that is supported so as to be movable back and forth between the take-out position and the release position of the injection molded product, and a front-back traveling body that is supported by this traveling body so as to be movable back and forth in the front-back direction. and a chuck portion which is mounted so as to be movable in the vertical direction by a vertically operating member attached to the front-rear traveling body, and an automatic take-out device for taking out an injection molded product, wherein either one of the traveling body and the front-rear traveling body or an induction motor drivingly connected to both; first and second bidirectional switching elements connected respectively to the main coil and the auxiliary coil to which capacitors are connected in parallel and for circulating AC power; a running body; An alternating current generator that outputs a detection signal with a voltage level corresponding to the moving speed of one or both of the front and rear moving bodies, and a counter circuit that memorizes the actual distance traveled by the driven body based on the voltage level of the number of input detection signals. a memory in which speed data corresponding to the running pattern of either or both of the running body and the front and rear running bodies is stored in advance; PID calculation is performed on the flow angle of the first or second bidirectional switching element based on the voltage level of the set speed signal accessed and converted into an analog signal and the detection signal, and the induction motor can be reversibly rotated. A capacitor travel type induction motor drive device equipped with a control device that performs variable control.