JP3866488B2 - Screw type injection molding machine position detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a position detection device for a screw-type injection molding machine that controls an injection stroke with a hydraulic controller and controls a plasticization stroke with an electric controller, for example.
[0002]
[Prior art]
2 and 3 are views showing two conventional examples of an injection device provided in a screw type injection molding machine as an example of a conventional hydraulic / electric hybrid machine. In the injection apparatus 20 of the injection molding machine in FIG. 2, a hydraulic controller 21 and an electric controller 22 are provided, and position detectors 23 and 24 are provided corresponding to these controllers 21 and 22. The position detector 23 includes a rod 23a connected to a screw (not shown) that moves in the heating cylinder 25, and a position detector 23b that detects the position of the screw by detecting the movement of the rod 23a. . Similarly, the position detector 24 includes a rod 24a connected to the screw that moves in the heating cylinder 25, and a position detector 24b that detects the movement of the rod 24a and detects the position of the screw. The hydraulic controller 21 and the electric controller 22 use the position data from the position detectors 23 and 24, respectively, to perform screw position control in the injection stroke and the plasticizing stroke.
[0003]
In the injection device 30 of FIG. 3, the hydraulic controller 31 and the electric controller 32 are configured to use the same position data of the position detector 33. Also in this case, the position detector 33 has a rod 33a connected to a screw that moves in the heating cylinder 35, and a position detector 33b that detects the position of the screw by the movement of the rod 33a. At the time of injection, the hydraulic controller 31 uses the position data from the position detector 33 to control the position of the screw, and at the time of plasticization, the electric controller 32 controls the position of the screw. When the electric controller 32 performs screw position control, the electric controller 32 must transmit and receive position data to and from the hydraulic controller 31.
[0004]
[Problems to be solved by the invention]
Of the two examples of the injection device provided in the conventional screw type injection molding machine described above, the injection device described above corresponds to a hydraulic controller for controlling the position of the screw and an electric controller. The detectors must be arranged, and the cost is high, and space for mounting two sets of position detectors must be secured. In addition to the position detector, a speed detector, a motor, an injection device moving unit, and the like must be disposed on the same surface as the position detector, and the installation location is often limited. In this regard, in the case of the injection device described later, since the same position detector is used, it is improved. However, when the electric controller performs control, position detection from the position detector is performed. There is a problem in that a signal must be communicated with the hydraulic controller, and a delay occurs in the processing of the position data, resulting in a decrease in reliability related to the position data processing.
[0005]
The present invention has been made to solve the above-described problem, and does not require a mounting space for two sets of position detectors, and exchanges position detection signals between the hydraulic controller and the electric controller. For example, an object of the present invention is to provide a position detection device for a screw-type injection molding machine provided with an injection device capable of controlling the position of a screw in an injection process and a plasticizing process.
[0006]
[Means for Solving the Problems]
To solve the aforementioned problems, the present invention is a position detecting device of the screw type injection molding machine which performs position control of the screw using a hydraulic controller (11) an electric controller (12) (13), wherein One position measuring rod (13a) connected to a screw, and first and second position detectors (13b, 13c) disposed on the rod with a predetermined interval, the rod The first and first positions are detected by detecting the moving position of (13a) and supplying the position data to the hydraulic controller (11) and the electric controller (12) to control the position of the screw by the respective controllers. And two position detectors (13b, 13c).
[0007]
According to such a structure, since the rod (13a) to be used is one, it does not require much space, and the hydraulic controller (11) and the electric controller (12) have the first and second positions. Since the position data from the detectors (13b, 13c) are given separately, there is no need to exchange position data between the hydraulic controller (11) and the electric controller (12), and the position data can be processed. Reliability can be improved without causing a delay.
[0008]
In the present invention , the hydraulic controller (11) controls an injection stroke of the injection device (10), the electric controller (12) controls a plasticizing stroke, and the rod (13a) is an injection device. It is connected to the screw of (10).
[0009]
According to such a configuration, it is possible to obtain an injection molding machine that is small in size and does not slow down data processing and has excellent reliability.
[0010]
In the present invention, the first and second position detectors (13b, 13c) are each constituted by an absolute encoder.
[0011]
According to the absolute encoder, the position signal can be easily obtained as a digital signal, and data input to the controller is facilitated.
[0012]
In the present invention, one of the hydraulic controller (11) and the electric controller (12) considers position data received by itself as a detection position, and the other sets the position data received by itself as an interval between the two. It is characterized by only adjusting it and considering it as a detection position.
[0013]
According to such a configuration, position data from each of the position detection units (13b, 13c) provided at different positions can be simultaneously acquired, and signal processing is not delayed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings by taking an example of an injection device of a screw type injection molding machine.
FIG. 1 is a configuration diagram showing an injection device provided in a screw type injection molding machine. The injection device 10 in FIG. 1 includes a hydraulic controller 11, an electric controller 12, and a position detector (position detection device) 13. The position detector 13 includes a rod 13a connected to the screw side of the injection device by a bracket, and position detectors 13b and 13c fixed to the frame side. In this example, the position detectors 13b and 13c are encoders, read the position of the rod 13a that moves together with the screw that moves in the heating cylinder 15, and output position data Sb and Sc that indicate the moved position, respectively. The hydraulic controller 11 and the electric controller 12 receive position data Sb and Sc output from the position detectors 13b and 13c of the position detector 13, respectively, and control the position of the screw in the injection stroke and the plasticizing stroke. .
[0015]
In the case described above, the position detection unit 13b and the position detection unit 13c are fixed to the same frame, and the distance D between them is fixed so as not to change. In this example, absolute encoders are used as the position detectors 13b and 13c, respectively, and the position detector 13b is attached to the reference position. In this case, the screw position detected by the position detection unit 13c is obtained by adding the interval D to the screw position detected by the position detection unit 13b. Under such conditions, the hydraulic controller 11 performs position control of the screw for injection of the molten resin, assuming that the position data Sb output from the position detection unit 13b indicates the actual position of the screw. The electric controller 12 considers that the position obtained by subtracting the interval D from the position data Sc output from the position detection unit 13c is the position of the screw, and controls the position of the screw for plasticizing the resin material. .
[0016]
In this embodiment, since only one rod 13a of the position detector 13 is arranged, the two rods 23a and 24a are arranged as in the case of arranging two position detectors as in the prior art. It does not need, and does not require space compared to the conventional one. Further, since the position detectors 13b and 13c independently acquire position data from the same rod 13a and can supply the position data to the hydraulic controller 11 and the electric controller 12 separately and simultaneously, Thus, there is no need to perform communication for exchanging position data between the hydraulic controller 11 and the electric controller 12, and the position control of the screw can be performed immediately, and there is a time delay in processing the position data. Does not occur.
[0017]
【The invention's effect】
The position detection device of the screw type injection molding machine according to the present invention is configured as described above, and since only one screw for position detection of the screw is arranged, the mounting space for two sets of position detectors In addition, since the hydraulic controller and the electric controller can be provided with position data separately from the first and second position detectors, the hydraulic controller and the electric controller are related to the position control between the hydraulic controller and the electric controller. It is possible to perform the respective control, for example, the position control of the screw in the injection process and the plasticizing process, without the need to exchange position data and without causing a time delay in the processing of the position data.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an injection device of a screw type injection molding machine according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing a conventional example of an injection device of a screw type injection molding machine.
FIG. 3 is a configuration diagram showing a conventional example of an injection device of a screw type injection molding machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Injection apparatus 11 Hydraulic controller 12 Electric controller 13 Position detector (position detection apparatus)
13a Rod 13b, 13c Position detector 15 Heating cylinder Sb, Sc Position data

Claims (4)

In the position detection device (13) of the screw type injection molding machine that controls the position of the screw using the hydraulic controller (11) and the electric controller (12),
One position measuring rod (13a) connected to the screw ;
First and second position detectors (13b, 13c) arranged on the rod with a constant interval, detecting a moving position of the rod (13a), and using the position data as the hydraulic pressure And first and second position detectors (13b, 13c) that are supplied to the controller (11) and the electric controller (12) and control the position of the screw by the respective controllers. A position detection device for a screw type injection molding machine. The hydraulic controller (11) controls the injection stroke of the injection device (10), the electric controller (12) controls the plasticizing stroke,
The position detection device for a screw-type injection molding machine according to claim 1, wherein the rod (13a) is connected to a screw of the injection device (10).   The position detection device for a screw type injection molding machine according to claim 1 or 2, wherein the first and second position detection units (13b, 13c) are each constituted by an absolute encoder.   One of the hydraulic controller (11) and the electric controller (12) considers position data received by itself as a detection position, and the other adjusts the position data received by itself by an interval between the two. The position detection device for a screw-type injection molding machine according to any one of claims 1 to 3, wherein

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