JPH05220806A - Resin extruder - Google Patents

Abstract

PURPOSE:To control the temperature of an extruded resin constantly by providing a plurality of heating means while being divided in the longitudinal direction of a cylinder and controlling each heating means on the basis of the deviation of a resin-temperature detecting value and a resin-temperature set value. CONSTITUTION:Three electric heaters 107-109 divided in the longitudinal direction of a cylinder 110 are wound on a cylinder body while an electric heater 114 is also wound on a cylinder head, and temperature sensors 117-120 are disposed in response to each electric heater 107-109, 114. A resin temperature sensor 123 is arranged to the exhaust port 113 of the cylinder 110, an output signal from the sensor 123 is input to a temperature-command signal generator 115, and PID arithmetic operation is conducted by an arithmetic circuit 121 together with a resin temperature set by a rheostat 122 and a temperature command signal is output. The temperature command signal is input to temperature controllers 103-106 at every electric heater 107-109, 114, and PID arithmetic operation is performed from the temperature command signal and outputs from the temperature sensors 117-120 and conduction is controlled separately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruded molding type connection part (EM) of an electric cable.
J) A resin extruder used for construction and the like.

[0002]

2. Description of the Related Art Conventionally, in the case of high voltage cables, it is necessary to improve the electrical performance of the connecting portions of the cables.
However, a resin extruder is used in the EMJ extrusion process and the like. FIG. 2 shows a general EMJ construction device.

In FIG. 2, crushed resin is supplied from a hopper 203 to a resin extruder 201. Resin extruder 2
The resin supplied to 01 is heated by a plurality of heaters to be liquefied, and then the mold 202 is passed through the pipe 206.
Is supplied to. In the mold 202 around which a plurality of heaters are wound, a connecting portion of a pair of cables 205 is arranged in order to apply insulation coating by EMJ, and the connecting portion of the cable 205 is molded by the resin. Control device 20
Reference numeral 4 sets the temperature of each part of the resin extruder 201 and the mold 202, and controls the driving of the screw in the resin extruder 201.

FIG. 3 is a view showing how the cable is subjected to EMJ processing in the mold, and the same parts as those in FIG. 2 are designated by the same reference numerals. In FIG. 3, a pair of cables 205 in which an insulator 304 is tapered and a conductor 302 is coupled by a sleeve 303 is housed in a mold 202. Although not shown, an internal semiconductive layer is formed on the sleeve 303. A plurality of electrothermal heaters 301 are wound around the die 202. In this state, the pipe 202 is inserted into the mold 202 from the resin extruder 201.
The resin 305 is supplied via 6. Then resin 30
5 is heat-processed in the mold 202 by the electric heater 301.

FIG. 4 is a diagram showing a conventional resin extruder used for EMJ construction. Screw drive unit 101
A hopper 102 for accommodating a granular resin (not shown) is provided on the upper part of the. A screw 111 is arranged inside the cylinder 110.
11 is rotated by a screw driving unit 101.
The cylinder 110 is divided into four parts, and three electric heaters 107 to 109 are wound around the cylinder body. The cylinder head 112 has an electric heater 11
4 is wound. Incidentally, the electric heaters 107 to 109
And 114 depict the cross section. Temperature controller 4
Reference numerals 03 to 406 are temperature controllers of a two-position (on / off) control system. The temperature controller 403 includes a variable resistor 407 for setting a resin temperature, which is connected to a reference voltage, and a control circuit 409 for driving an electric heater. A temperature sensor 408 that measures the resin temperature is embedded in the cylinder 110. The control circuit 409 compares the temperature signal output from the temperature sensor 408 with the output voltage of the variable resistor 407 and outputs a two-position control signal corresponding to the difference between the two signals to the electric heater 107. As a result, the electric heater 107 heats the resin so that the temperature of the resin becomes equal to the resin temperature set by the variable resistor 407.

The temperature controllers 404 to 406 have the same structure as the temperature controller 403, and the temperature controllers 403 to 403 are based on the temperature signals from the corresponding temperature sensors 408 to 411.
Perform the same operation as. However, since the set values of the variable resistors 407 are different, the temperature controllers 403 to 406 control the corresponding parts of the resin extruder to different temperatures.

As described above, the electric heaters 107 to 10
Cylinder body and cylinder head 11 by 9, 114
By heating the screw 2 and rotating the screw 111 by the screw driving unit 101, the granular resin stored in the hopper 102 is made into a liquid state, and is extruded from the cylinder head 112 to the mold 202 through the pipe 206. Is possible.

[0008]

The resin temperature is set by setting a variable resistor 407 provided in each of the temperature controllers 403 to 406, and heat generated by friction with the resin, screw and cylinder is set. If the resin temperature does not reach the specified value due to factors such as
Since it is necessary to reset No. 7, there is a problem that the operation for setting the temperature is extremely complicated.

Even if each variable resistor 407 is set, the resin temperature at the discharge port 113 changes due to a change in environmental temperature or heat generated by friction between the resin, the screw and the cylinder. Couldn't manage to. The present invention has been made in view of the above problems, and an object of the present invention is to provide a resin extruder in which the temperature can be easily set and the resin temperature can be accurately controlled.

[0010]

The resin extruder of the present invention comprises:
A cylinder, a screw that is disposed in the cylinder and that pushes out resin in the cylinder, a plurality of heating units that are disposed separately in the length direction of the cylinder, and the heating units that are provided corresponding to the heating units. A plurality of temperature control means for controlling the heating temperature by the corresponding heating means based on the temperature command signal, a resin temperature detecting means for detecting the resin temperature at the discharge port of the cylinder, and a temperature detected by the resin temperature detecting means. And temperature command signal generating means for outputting the temperature command signal to each of the temperature control means based on a deviation from a preset resin temperature.

[0011]

The temperature command signal generating means outputs a temperature command signal to each temperature control means based on the deviation between the resin temperature at the discharge port detected by the resin temperature detecting means and the preset resin temperature. Each temperature control means controls the heating temperature of the corresponding heating means based on the temperature command signal, whereby the resin temperature at the discharge port is controlled to be constant. The resin is pushed out of the discharge port by a screw through the cylinder.

[0012]

FIG. 1 is a diagram showing an embodiment of the present invention.
In FIG. 1, a hopper 102 for accommodating granular resin (not shown) is provided above the screw driving unit 101. The cylinder 110 is composed of a cylinder body and a cylinder head 112. Cylinder 1
A screw 111 is disposed inside the screw 10, and the screw 111 is rotationally driven by the screw driving unit 101.

A temperature sensor 123 for detecting the resin temperature and outputting a corresponding temperature signal is arranged at the discharge port 113 of the cylinder 110. The temperature sensor 123 is embedded in the vicinity of the inner wall surface of the discharge port 113 in order to detect the resin temperature more accurately. The temperature sensor 123 constitutes a resin temperature detecting means. A temperature command signal generator 115 as a temperature command signal generating means is connected to the temperature sensor 123. The temperature command signal generator 115 is composed of a variable resistor 122 for setting the resin temperature and an arithmetic circuit 121 which are connected to a reference voltage. First of arithmetic circuit 121
The input section is connected to the variable resistor 122, and the second input section is connected to the temperature sensor 123. Also, the output part is
It is connected to each of the first input sections of the temperature controllers 103 to 106 as temperature control means. Temperature command signal generator 11
5 performs a PID calculation described later based on the signal representing the resin temperature set by the variable resistor 122 and the temperature signal from the temperature sensor 123, and outputs a temperature command signal.

Three electric heaters 107 to 109 divided in the length direction of the cylinder 110 are wound around the cylinder body, and the cylinder head 112 also has an electric heater 114.
Is wound. Here, the electric heaters 107 to 10
Reference numerals 9 and 114 constitute heating means. The electric heaters 107 to 109, 114 are shown in cross section. Temperature sensors 117 to 120 are arranged corresponding to the electric heaters 107 to 109 and 114, respectively. Temperature sensor 117
Nos. To 120 are embedded near the inner wall surface of the cylinder 110 in order to detect the resin temperature more accurately. Temperature controllers 103 to 106 are provided corresponding to the electric heaters 107 to 109 and 114 and the temperature sensors 117 to 120. Each first input section of the temperature controllers 103 to 106 is connected to the output section of the temperature command signal generator 115. Each second input of the temperature controllers 103 to 106 is connected to the corresponding temperature sensor 117 to 120. Further, the output parts of the temperature controllers 103 to 106 are connected to the corresponding electric heaters 107 to 109, 114. The temperature controllers 103 to 106 perform PID calculation described later based on the temperature signals from the corresponding temperature sensors 117 to 120 and the temperature command signal from the temperature command signal generator 115, and the corresponding electric heaters 107.
Drive control of 109 to 114 is performed.

The operation of the resin extruder constructed as above will be described below. The variable resistor 122 is connected to the outlet 113.
It is assumed that the resin temperature in is set to a predetermined value (for example, 120 ° C.). First, the temperature sensor 12
3 detects the resin temperature at the discharge port 113 and outputs a temperature signal corresponding to the temperature. The arithmetic circuit 118 performs the following PID calculation based on the output signal of the variable resistor 122 and the temperature signal from the temperature sensor 123, and outputs a temperature command signal.

The temperature controllers 103 to 106 are
The following PID calculation is performed based on the temperature signals from the temperature sensors 117 to 120 and the temperature command signal from the temperature command signal generator 115, and the corresponding electric heaters 107 to 109, 114 are drive-controlled based on the calculation results. P
The ID control formula is generally

[0017]

[Equation 1]

It is represented by Where PB is the proportional band, T _I
Is integration time, T _D is derivative time, m (t) is control output, and e (t) is control deviation. When this is applied to digital control,
Since it involves a sampling operation, it can be expressed by a difference equation. The control output m (t) when the data at the present time is taken as e _n from the captured data and is traced back to e _n-1 , e _n-2 ...

[0019]

[Equation 2]

It can be expressed as Where 100 / P
If B is K, 1 / Ti is I, Td is D, and ΔT is Ts,

[0021]

[Equation 3]

It becomes In this example, the resin temperature was controlled based on the equation (3). Under the temperature control as described above, the screw driving unit 101 drives the screw 111 to rotate. This allows the hopper 102
The resin stored inside can be made into a liquid state, can be extruded from the discharge port 113, and can be supplied to the die 202 via the pipe 206. As described above, in the resin extruder of this embodiment, the temperature sensor 123 detects the resin temperature at the discharge port 113 of the cylinder 110, and the temperature command signal generator 115.
Performs PID calculation based on the deviation between the temperature detected by the temperature sensor 123 and the resin temperature preset by the resistor 122, and outputs a temperature command signal to the temperature controllers 103 to 106. The temperature controllers 103 to 106 perform PID calculation based on the temperature command signal and the temperature signals from the temperature sensors 117 to 120, and control the heating temperature by the corresponding electric heaters 107 to 109, 114.

Therefore, the temperature controllers 103 to 106
Does not require temperature setting, and temperature setting is performed only in the temperature command signal generator 115, so that the temperature setting operation becomes extremely easy. Further, since the resin temperature at the discharge port 113 is detected and the temperature of each part of the cylinder 110 is controlled based on the detected temperature, the resin temperature at the discharge port 113 becomes constant and even when the environmental temperature changes or the like. It is possible to keep the temperature of the extruded resin constant.

Further, in the above-mentioned conventional resin extruder, since the temperature controller of the two-position control system is used, when the cylinder temperature deviates from the set value, the temperature control operation changes from on to off or from off. Since it changes extremely to ON, hunting occurs in the temperature control result, and it is difficult to control the temperature of the extruded resin constantly and stably. However, in the resin extruder of this embodiment, the temperature controller 103 to 106 and the temperature command signal generator 115
Since the temperature is controlled by the ID operation, it is possible to control the resin temperature in a stable manner without variations, and also to make a quick response to a disturbance.

In this embodiment, the temperature command signal generator 1
Although not only the temperature controller 15 but also the temperature controllers 103 to 106 of the PID control type are mentioned, the temperature controllers 103 to 106 use a proportional control type temperature controller when high-precision temperature control is not required. Good. Even in this case, the temperature setting is extremely easy. In addition, stable temperature control is possible, and quick response to external disturbance is possible.
It is possible to maintain the resin temperature at a predetermined constant value.

[0026]

The resin extruder of the present invention is particularly provided with a plurality of heating means dividedly arranged in the length direction of the cylinder and corresponding heating means, and is provided on the basis of the temperature command signal. A plurality of temperature control means for controlling the heating temperature by the corresponding heating means, and outputs the temperature command signal to each temperature control means based on the deviation between the temperature detected by the resin temperature detection means and the preset resin temperature. Since the temperature command signal generating means is provided, the temperature can be set extremely easily and the temperature of the resin to be extruded can be controlled to be constant.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a general EMJ construction device.

FIG. 3 is a diagram showing how a cable is generally subjected to EMJ processing in a mold.

FIG. 4 is a view showing a conventional resin extruder.

[Explanation of symbols]

103 to 106 ... Temperature controller as temperature control means 107 to 109, 114 ... Electric heater as heating means 110 ... Cylinder 111 ... Screw 113 ... Discharge port 115 ... Temperature Temperature command signal generator 123 as command signal generating means ... Electric heater as resin temperature detecting means

Claims (1)

[Claims] 1. A cylinder and a cylinder disposed in the cylinder,
A screw for pushing out the resin in the cylinder, a plurality of heating means divided and arranged in the length direction of the cylinder, and heating provided corresponding to each of the heating means and corresponding to a temperature command signal. A plurality of temperature control means for controlling the heating temperature by means, a resin temperature detection means for detecting the resin temperature at the discharge port of the cylinder, and a deviation between the detection temperature of the resin temperature detection means and the preset resin temperature. A resin extruder, comprising: temperature command signal generating means for outputting the temperature command signal to each of the temperature control means based on the temperature control signal generating means.