Fusion cutting device and control method for fusion cutting device

Abstract

To provide a fusion cutting device that accurately measures the temperature of a heating wire in a non-contact manner and precisely controls the temperature of the heating wire.SOLUTION: A fusion cutting device includes: a first arm and a second arm; a heating wire stretched between these two arms; vibration means which vibrates the heating wire; vibration frequency measurement means which measures a vibration frequency of the heating wire; and voltage control means which controls a voltage applied to the heating wire. The vibration frequency measurement means measures the vibration frequency of the heating wire in a non-contact manner. The voltage control means calculates a temperature of the heating wire on the basis of the vibration frequency of the heating wire measured by the vibration frequency measurement means and controls the voltage to be applied to the heating wire such that the temperature of the heating wire is within a prescribed temperature range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fusing device and a method for controlling the fusing device. [Background technology]

[0002] Thin resin sheets, such as separators used in secondary batteries for electric vehicles, are easily deformed, making it difficult to cut them accurately with a mechanical cutter. For this reason, the mainstream method for cutting thin resin sheets is the thermal cutting method, which uses a heated electric wire to melt the target object. In order to stably cut with good dimensional accuracy using the thermal cutting method, it is necessary to accurately control the temperature of the heating wire within an appropriate temperature range. For example, if the temperature of the heating wire is too high, the separator may melt up to the periphery of the melting part, and the cut surface may not be linear, and if the temperature of the heating wire is too low, the separator may not be melted.

[0003] In light of the above, it is important to accurately control the temperature of the heating wire in the fusing device. A common temperature measurement method is a contact temperature measurement method in which a temperature sensor such as a thermocouple is brought into contact with the heating wire. However, with a cutter that has a small thermal capacity, such as a thin-diameter heating wire, there is a problem that the temperature of the cutter changes when the temperature sensor comes into contact with the cutter.

[0004] In order to avoid such temperature changes of the heating wire due to contact, methods of measuring the temperature without contact have been considered. For example, Patent Document 1 discloses a technology in which the wavelength of light emitted by a red-hot cutter is detected to measure the temperature of the cutter, and the cutter temperature is controlled within a predetermined range by feedback control. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 58-166000 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method of calculating temperature from the wavelength of light radiated by an object as in Patent Document 1 has a problem in that it is difficult to accurately measure the temperature of an object with a small area, such as a heating wire.When measuring the temperature of an object with a small diameter, such as a heating wire, the area of ​​the background is overwhelmingly larger than the area of ​​the object to be measured, making it difficult to extract only the radiation of the object from the background radiation and measure the temperature accurately.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a fusing device that can accurately measure the temperature of a heating wire in a non-contact manner and precisely control the temperature of the heating wire. [Means for solving the problem]

[0008] In order to solve the above problems, the fusing device of the present invention is a fusing device that fusing an object to be cut, and includes an electric heating wire stretched between a first arm and a second arm, a vibration means for vibrating the electric heating wire, a vibration frequency measuring means for measuring the vibration frequency of the electric heating wire vibrated by the vibration means, and a voltage control means for calculating the temperature of the electric heating wire based on the vibration frequency of the electric heating wire and applying a voltage to the electric heating wire so that the temperature of the electric heating wire is within a predetermined temperature range, wherein the voltage control means monitors the calculated temperature of the electric heating wire and uses the temperature of the electric heating wire to feed back to the voltage applied to the electric heating wire, thereby controlling the temperature of the electric heating wire within a predetermined range, and while the voltage control means maintains the temperature of the electric heating wire, a moving mechanism moves the electric heating wire in the direction of the object to be cut and brings it into contact with the object to be cut, thereby fusing the object to be cut.

[0009] In addition, the control method of the fusing device of the present invention is a control method of a fusing device that fusing an object to be cut by vibrating an electric heating wire stretched between a first arm and a second arm, measuring the frequency of the vibrated electric heating wire, calculating the temperature of the electric heating wire based on the measured frequency of the electric heating wire, and controlling the voltage applied to the electric heating wire so that the temperature of the electric heating wire is within a predetermined temperature range, and the calculated temperature of the electric heating wire is monitored and the temperature of the electric heating wire is used to feed back to the voltage applied to the electric heating wire, thereby controlling the temperature of the electric heating wire within a predetermined range, and while maintaining the temperature of the electric heating wire, a moving mechanism is used to move the electric heating wire in the direction of the object to be cut and bring it into contact with the object to be cut, thereby fusing the object to be cut. Effect of the Invention

[0010] The effect of the present invention is to provide a fusing device that can accurately measure the temperature of a heating wire in a non-contact manner and control the temperature of the heating wire with high precision. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram showing a fusing device according to a first embodiment; [Diagram 2] FIG. 11 is a block diagram showing a fusing device according to a second embodiment. [Diagram 3] 6 is a flowchart showing the operation of the fusing device of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the embodiments described below are limited in a technically preferable manner for carrying out the present invention, but the scope of the invention is not limited to the following. Note that the same components in each drawing are given the same numbers, and the description may be omitted.

[0013] (First embodiment) 1 is a block diagram showing a fusing device 10 of this embodiment. The fusing device 10 has a first arm 1, a second arm 2, a heating wire 3 stretched between these two arms, a vibration means 4 for vibrating the heating wire 3, a vibration frequency measuring means 5 for measuring the vibration frequency of the heating wire 3, and a voltage control means 6 for controlling the voltage applied to the heating wire 3. The vibration frequency measuring means 5 measures the vibration frequency of the heating wire 3 in a non-contact manner. The voltage control means 6 calculates the temperature of the heating wire 3 based on the vibration frequency of the heating wire 3 measured by the vibration frequency measuring means 5, and controls the voltage applied to the heating wire 3 so that the temperature of the heating wire 3 is within a predetermined temperature range.

[0014] With the above-described configuration, the temperature of the heating wire can be measured and accurately controlled without causing any disturbance to the temperature of the heating wire.

[0015] Second embodiment In this embodiment, a specific configuration example of the fusing device having the basic configuration of the first embodiment will be described. FIG. 2 is a block diagram showing the fusing device 1000 of this embodiment. The fusing device 1000 has a heating wire base 100, a first arm 110 and a second arm 120 fixed to the heating wire base 100, and a heating wire 200 stretched between the first arm 110 and the second arm 120. The fusing device 1000 also has a moving mechanism 300 for moving the heating wire base 100. The moving mechanism 300 moves the heating wire 200 heated to a predetermined temperature, thereby fusing the target object. In this embodiment, it is necessary to vibrate the heating wire 200 in order to measure the temperature of the heating wire 200. For this purpose, the fusing device 1000 is provided with a vibration mechanism 310. The vibration mechanism 310 can be arranged on the heating wire base 100, for example. The vibration mechanism 310 can generate vibrations in the heating wire 200 by plucking the heating wire 200 with a claw-shaped part, for example, in the same way as plucking a guitar string with a pick. The vibrating heating wire 200 generates sound. To capture this sound, the fusing device 1000 has an acoustic sensor 400. For the acoustic sensor 400, a highly sensitive sensor using, for example, micromachining technology or optical fiber is used, and it is placed near the heating wire.

[0016] The fusing device 1000 also has an initial temperature sensor 510 that measures the initial temperature of the heating wire 200 when no voltage is applied to the heating wire 200. The fusing device 1000 also has a frequency converter 520 that converts the sound collected by the acoustic sensor 400 into a frequency, and a control unit 500 that receives the output of the initial temperature sensor 510 and the output of the frequency converter 520, calculates the temperature, and controls the voltage applied to the heating wire 200. The frequency converter 520 converts the sound collected by the acoustic sensor 400 into an amplitude (spectrum) for each frequency. The control unit 500 specifies the fundamental frequency of the heating wire 200 based on this spectrum. The fundamental frequency can be specified by narrowing the frequency range based on the fundamental frequency specified in the initial state and selecting a frequency with a large amplitude from within the range. The voltage is controlled by, for example, feeding back the calculated temperature of the heating wire 200 to the voltage applied to the heating wire 200. In order to control the voltage applied to the heating wire 200, the fusing device 1000 has a power source 530 and a relay 540, which are controlled by the control unit 500.

[0017] Next, a method for controlling the fusing device 1000 will be described. FIG. 3 is a flowchart showing the method for controlling the fusing device 1000. First, the vibration mechanism 310 vibrates the heating wire 200 (S1). The vibration mechanism 310 can vibrate the heating wire 200, for example, by flicking the heating wire 200. Next, the initial temperature of the heating wire 200 before a voltage is applied to the heating wire 200 and the initial vibration frequency of the heating wire 200 are measured (S2). In the initial state, the temperature of the heating wire 200 is equal to the temperature in the vicinity of the heating wire 200, so the initial temperature sensor 510 can measure, for example, the temperature in the vicinity of the heating wire 200 and use this as the temperature of the heating wire 200. In addition, the vibration sound of the heating wire 200 vibrating in the initial state is collected by the acoustic sensor 400, and converted to a vibration frequency by the vibration frequency converter 520 to measure the vibration frequency. The vibration frequency at that time is designated as F0.

[0018] Here, a method for calculating the temperature of the heating wire 200 will be described. First, the temperature of the heating wire 200 in the initial state when no voltage is applied to the heating wire 200 is taken as initial temperature t0. Also, the initial vibration frequency of the heating wire is taken as F0. Here, if the tension of the heating wire 200 is T0, the length of the heating wire 200 is L, and the mass per unit length of the heating wire 200 is W, then the vibration frequency F0 can be calculated by the following formula. F0 = 1 / (2L) × (T0 / W) 1 / 2 (1) Convert equation (1) into an equation for calculating tension T0. T0=4L 2 ×F0 2 ×W (2) Next, the elongation ΔL of the heating wire 200 due to the tension T0 T If the Young's modulus (modulus of longitudinal elasticity) of the heating wire is E and the cross-sectional area of ​​the heating wire is A, then ΔL T can be calculated using the following formula: ΔL T =T0×L / (E×A) (3) Substituting equation (2) into equation (3) gives the following equation. ΔL T =4L 2 ×F0 2 x W x L / (E x A) ΔL T =4L 3 ×F0 2 ×W / (E×A) (4) Next, obtain the temperature t when a voltage is applied to raise the temperature of the heating wire 200. Since the wire temperature when no voltage is applied to the heating wire 200 is t0, if the temperature rise is Δt, Δt can be calculated using the following formula. Δt = t - t0 (5) If the linear expansion coefficient of the heating wire 200 is α, the expansion of the heating wire due to the temperature rise of the heating wire 200 is ΔL. H can be calculated using the following formula: ΔL H =L×α×Δt (6) Substitute equation (5) into equation (6). ΔL H = L × α × (t-t0) (7) When a voltage is applied to the heating wire 200 to raise the temperature of the heating wire 200, the heating wire 200 is heated by ΔL calculated by the formula (7). H The tension in the heating wire 200 decreases as the wire stretches by T. If the tension in the heating wire at this time is T, the following equation is obtained. ΔL T -ΔL H =T×L / (E×A) (8) The relationship between the vibration frequency F of the heating wire 200 and the tension T of the heating wire 200 is expressed by the following formula. F = 1 / (2L) × (T / W) 1 / 2 (9) Equation (9) is converted into an equation for calculating tension T. T=4L 2 ×F 2 ×W (10) Substitute equations (4), (7), and (10) into equation (8). 4L 3 ×F0 2 ×W / (E×A)-L×α(t-t0)=4L 3 ×F 2 ×W / (E×A) (11) Convert equation (11) into an equation to find t. t=4L 2 ×W / (E×A×α)×(F0 2 -F 2 )+t0(12) In formula (12), L, W, E, A, and α are known values. Therefore, the temperature (t) of the heating wire 200 can be calculated from the temperature (t0) of the heating wire 200 before a voltage is applied to the heating wire 200, the frequency (F0), and the frequency (F) when the temperature of the heating wire 200 is detected.

[0019] 3, the operation of the fusing device 1000 will now be described. According to the above-described procedure, the control unit 500 calculates the temperature of the heating wire 200 at a predetermined sampling time based on the output of the frequency converter 520, and starts monitoring this temperature (S3).

[0020] Next, a voltage is applied to the heating wire 200, and the monitored temperature of the heating wire 200 is fed back to the voltage, and control of the temperature of the heating wire within a predetermined range is started (S4). In this control, the control unit 500 outputs a signal to the relay 540 to apply / cut off the voltage to the heating wire. The temperature control of the heating wire 200 can be performed by a general control method such as PID (Proportional-Integral-Differential) control. Also, although an example in which the relay 540 is used to control the temperature of the heating wire 200 has been described above, a variable voltage power supply, a thyristor phase control device, or the like may be used instead of the relay 540.

[0021] While maintaining the temperature of the heating wire 200 by the above-mentioned temperature control, the moving mechanism 300 is used to move the heating wire 200 toward the object to be cut and bring it into contact with the object to be cut, thereby cutting the object (S5). After that, while continuing the temperature control, a predetermined number of cuts are performed, and the process ends.

[0022] In the above description, the heating wire 200 is moved by the moving mechanism 300 to perform melting, but the object to be melted may be moved in the direction of the heating wire 200. Furthermore, in either case of moving, it is desirable to set the target movement position of the heating wire 200 relative to the object to be melted farther away from the object to be melted, such as a sheet. In this way, the heating wire 200 moves away from the object to be melted immediately after melting, so that the transfer of heat to the object to be melted more than necessary is suppressed, and the melted surface can be made smooth.

[0023] As described above, according to the present embodiment, the temperature of the heating wire can be measured in a non-contact manner, and stable temperature control can be performed. As a result, a fusing device capable of performing stable fusing processing can be provided even when fusing is performed repeatedly.

[0024] The present invention has been described above using the first and second embodiments as exemplary examples. However, the present invention is not limited to the above-mentioned embodiments. That is, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention. [Explanation of symbols]

[0025] 1, 110 First Arm 2, 120 Second Arm 3, 200 heating wire 4. Vibration means 5. Means of measuring vibration frequency 6 Voltage Control Means 300 Moving mechanism 310 Vibration mechanism 400 Acoustic Sensor 500 Control section 510 Initial Temperature Sensor 520 Frequency Converter 530 Power supply 540 Relay

Claims

1. A fusing device for fusing an object to be fusing, comprising: a heating wire stretched between the first arm and the second arm; A vibration means for vibrating the heating wire; a vibration frequency measuring means for measuring the vibration frequency of the heating wire excited by the vibration means; a voltage control means for calculating a temperature of the heating wire based on a vibration frequency of the heating wire and applying a voltage to the heating wire so that the temperature of the heating wire is within a predetermined temperature range; having the voltage control means monitors the calculated temperature of the heating wire and uses the temperature of the heating wire to feed back to a voltage applied to the heating wire, thereby controlling the temperature of the heating wire within a predetermined range; While the voltage control means maintains the temperature of the heating wire, a moving mechanism moves the heating wire toward the object to be melted and brings the heating wire into contact with the object to be melted, thereby melting the object to be melted. A fusing device comprising:

2. The vibration frequency measuring means is Has an acoustic measurement means 2. The fusing device according to claim 1.

3. An initial temperature measuring means is provided for measuring the temperature of the heating wire before a voltage is applied to the heating wire.

3. The fusing device according to claim 1 or 2.

4. The voltage control means The voltage is controlled by PID control.

4. The fusing device according to claim 1, wherein the fusing device is a fusing device.

5. A heating wire stretched between the first arm and the second arm is excited, Measure the vibration frequency of the excited heating wire; Calculating the temperature of the heating wire based on the measured vibration frequency of the heating wire; A method for controlling a fusing device that fuses an object to be fusing by controlling a voltage applied to the heating wire so that the temperature of the heating wire falls within a predetermined temperature range, comprising: The calculated temperature of the heating wire is monitored, and the temperature of the heating wire is fed back to a voltage applied to the heating wire to control the temperature of the heating wire within a predetermined range; While maintaining the temperature of the heating wire, a moving mechanism is used to move the heating wire toward the object to be melted and bring it into contact with the object to be melted, thereby melting the object to be melted. A method for controlling a fusing device.

6. The frequency is measured based on an acoustic measurement.

6. The method for controlling a fusing device according to claim 5.

7. The temperature of the heating wire is measured before a voltage is applied to the heating wire.

7. A method for controlling a fusing device according to claim 5 or 6.

8. The voltage is controlled by PID control.

8. A method for controlling a fusing device according to claim 5.

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