JP3557238B2 - Temperature control method for conform extruder - Google Patents

Description

[0001]
[Industrial applications]
The present invention is to feed and heat / melt a metal filament to be compressed and heated to a holder provided with a heater for preheating, and to apply the molten metal to an outer peripheral surface of a wire simultaneously fed toward the holder. The present invention relates to a conform extruder to be coated, and more particularly to a temperature control method for a conform extruder capable of maintaining a heater at a constant temperature.
[0002]
[Prior art]
For example, a conform extruder as shown in FIG. 6 has been developed and used for manufacturing a coaxial cable.
The conform extruder feeds a wire 101 to be coated toward a die holder 100, and simultaneously compresses a metal wire 102 to be fed, thereby heating and melting the metal wire 102 to a melting temperature of the metal 102 or higher. At the same time, the wire 102 is fed into a die 103 to cover the outer peripheral surface of the wire 101 with the metal 102.
Usually, in this conform extruder, the die holder 100 is preliminarily heated separately from the compression heat, and from the beginning of the extruding operation, the metal wire 102 is ensured in a stable and stable molten state. A cartridge type heater (not shown) is provided inside the heater panel 104 on the outer surface side of the die holder because it can generate a high temperature (for example, around 600 ° C. to 800 ° C.) and needs to be frequently replaced in a short cycle. It is.
[0003]
By the way, in such a conventional conform extruder, if a constant power is always supplied to the heater, the internal temperature of the die holder is gradually maintained due to an imbalance between the heat generation amount and the heat release amount. Since the temperature may rise and eventually exceed the heat resistant temperature of the heater, a temperature detecting means is provided near the heater, and when the temperature exceeds a specific temperature, the power supply to the heater is stopped. .
[0004]
[Problems to be solved by the invention]
However, in such a conventional conform extruder, when the power supply operation to the heater is repeatedly turned on and off, the mechanical strength of the heater is reduced or an oxidation phenomenon is promoted, resulting in a reduction in life. I have.
In addition, since the intrinsic melting temperature of the metal wire is uniquely determined, it is necessary to always maintain the optimum temperature for the melting temperature of the metal wire in the die holder. When the heater is turned on / off, the temperature in the melting chamber greatly fluctuates, and when the temperature is lowered, the temperature may be lower than the melting temperature, which may result in defective melting.
[0005]
In view of the above circumstances, the present invention can keep the temperature of the die portion in the die holder constant, and can always keep the heating operation of the heater in an optimum state so as not to exceed the heat-resistant temperature. It is an object of the present invention to provide a method for controlling the temperature of a conform extruder.
[0006]
[Means for Solving the Problems]
That is, the present invention is the die chamber in the die holder that attached the heater for pre heat causes heating and melting by feeding metal striatal be compressed heated, the wire toward the die holder comes fed simultaneously In a conform extruder that coats the outer peripheral surface with the molten metal, the first temperature is higher than the melting temperature of the metal wire, and the second temperature is higher than the melting temperature of the metal wire. (T1 ≦ T ≦ T2), wherein the control unit increases or decreases the amount of power to the heater in accordance with the measured temperature in the die chamber. In both cases when the temperature approaches the second temperature and when the temperature decreases and approaches the first temperature, the temperature gradient with respect to the time of the changing temperature is used in advance. Kino target value, i.e. to predict the arrival time of the second temperature or the first temperature, faster predetermined infinitesimal time than its time, in which to perform the predetermined current amount control to the heater.
[0007]
[Action]
According to the present invention, when the temperature of the die chamber in which the metal wire in the holder melts exceeds the first temperature, the temperature detecting means detects the temperature and outputs a predetermined signal. The operation of is suppressed.
Further, when the inside of the die chamber drops to the second temperature, the temperature detecting means detects this and outputs a predetermined signal, and the operation of the heater suppressed by the control from the control unit which has input this signal is increased, Thus, temperature control is always performed within a certain range.
[0008]
【Example】
Hereinafter, the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a sectional view of an essential part showing an embodiment of a conform extruder to which a temperature control method according to the present invention is applied. The conform extruder of this embodiment includes a temperature detection means 2 in a die chamber (melting chamber) 1A inside a die holder 1 and a control unit 3 (which outputs a signal corresponding to a detected temperature from the temperature detection means 2 ( 3) and a heater 4 whose operation is controlled by the control unit 3.
[0009]
In the figure, reference numeral 5 denotes a wire having an outer periphery of a center conductor coated with an appropriate coating (polyethylene foam in this embodiment), and 6 denotes a metal wire using aluminum, which is heated together with Joule heat by a heater 4 in a die chamber 1A. After being self-heated and melted by compression, it is formed into a pipe shape by a die 7 and is externally provided as an external conductor 6 ′ on the outer peripheral surface of the wire 5. Reference numeral 8 in the figure denotes a wheel that feeds a pair of metal filaments 6 into the die chamber 1A at the same time.
[0010]
A temperature measuring resistor or a platinum resistor is used for the temperature detecting means 2, and a predetermined signal is output to the control unit 3 in accordance with the detected temperature.
[0011]
The control unit 3 controls the inside of the die chamber (melting chamber) 1A within an optimum set temperature range according to the melting temperature of aluminum to be melted, specifically, as shown in FIG. The temperature is varied and changed within a range from a first temperature (T1) to a second temperature (T2, where T1 <T2). Therefore, as shown in FIG. 3, the input of the control unit 3 is connected to the output of the temperature detecting means 2, and the output is connected to the heater 4.
[0012]
That is, the control operation of the control unit 3 will be described in more detail . In FIG. 4, a temperature change (ΔT) per unit time (Δt), that is, a temperature gradient tan θ = ΔT / Δt
After determining the temperature rise angle θ from
The time (t ₀ ) when the temperature reaches the second temperature (T2) is predicted from the following equation in advance,
t ₀ = (T2−T1) / tan θ
A predetermined minute time before reaching the time, the amount of current (current value) to the heater 4 is suppressed to a predetermined value. Further Thus hereinafter, 'the, likewise time reaches the first temperature (T1) (t 0 temperature falling angle when the temperature began to drop _(theta)' by predicting) in advance from the following equation,
t ₀ ′ = (T 2 −T 1) / tan θ ′
And it is adapted to Koshin amount of current supplied to the heater 4 (current value) to a predetermined value before a predetermined minute time to reach that time.
[0013]
The heater 4 is, as shown in FIG. 5, the outer circumferential surface of the die holder 1 is attached removably (upper surface and both side surfaces) inside the heater plate 4A attached to, turned so that to heat in response to energization amount I have.
[0014]
Therefore, according to this embodiment, since the inside of the die chamber (melting chamber) 1A constantly fluctuates and changes within a constant temperature range, that is, within the melting temperature of the metal filament, the melting caused by the temperature drop is caused. It is possible to prevent troubles such as defects from occurring.
[0015]
【The invention's effect】
As described above, according to the present invention, when the die chamber in which the metal wire in the die holder melts approaches the second temperature beyond the first temperature , the temperature detecting means detects this and outputs a predetermined signal. outputs, has become a signal from the control unit that has received the signal so as to suppress the operation of the heater and then the temperature in the die chamber approaches the first temperature decreases from the second temperature, the temperature The detection means detects this and outputs a predetermined signal, and the control signal from the control unit which has input this signal increases the operation of the suppressed heater, thus controlling the temperature within a constant range at all times. since it is possible to perform, not only can prevent the occurrence of molten defect of the metal striatum, because it is possible to hold the heating operation so as not to exceed the heat resistant temperature of the heater at all times the optimum conditions, the durability of the heater An effect can be improved.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a main part of an embodiment of a conform extruder to which a temperature control method according to the present invention is applied.
FIG. 2 is a graph illustrating a temperature control method according to the present invention.
FIG. 3 is a configuration block diagram showing a main part of a conform extruder to which the temperature control method according to the present invention is applied.
FIG. 4 is an explanatory diagram for explaining a temperature control method according to the present invention.
FIG. 5 is a schematic diagram showing an arrangement of heaters in a conform extruder to which the temperature control method according to the present invention is applied.
FIG. 6 is a perspective sectional view illustrating a conventional conform extruder.
[Explanation of symbols]
1 Die holder 1A Die chamber 2 Temperature detecting means 3 Control unit 4 Heater 5 Wire 6 Metal wire

Claims (1)

A die chamber of the heater (4) in the die holder (1) which is attached to for pre heat (1A), with is heated and melted by feeding metal striatal be compressed heated (6), wherein the die holder (1) The temperature (T) in the die chamber (1A) is controlled by the metal wire (5) in a conform extruder that coats the molten metal on the outer peripheral surface of the wire (5) that is simultaneously fed into the die. 6) A temperature control method for adjusting and controlling a temperature between a first temperature (T1) higher than the melting temperature and a second temperature (T2) higher than this, that is, T1 ≦ T ≦ T2,
When the temperature (T) rises and approaches the second temperature (T2) by the control unit (3) that adjusts the amount of electricity to the heater (4) according to the measured temperature in the die chamber (1A). In either case, when the temperature decreases and approaches the first temperature (T1), the target value at that time, that is, the second temperature (T2) or the first temperature (T2) or the first temperature (T2) is previously determined from the temperature gradient with respect to the time of the changing temperature. predicted temperature (T1) time to reach the (t _{0, t} 0 _'), early certain minute time than that time elapses, and characterized in that to perform the predetermined current amount control to the heater (4) Temperature control method for conform extruder.

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