A method and circuit for regulating temperature for hot bar welding

Abstract

The present application relates to the technical field of hot pressure welding, and discloses a method and circuit for temperature control and gear adjustment of hot pressure welding. The temperature control and gear adjustment circuit comprises a power grid, anti-parallel thyristors, a power frequency transformer and a resistor. The power grid is connected to the input end of the anti-parallel thyristors and the second pin of the power frequency transformer, and the output end of the anti-parallel thyristors is connected to the first pin of the power frequency transformer. The third pin of the power frequency transformer is connected to the resistor. The method comprises the following steps: the gear adjustment control switch outputs a matching gear adjustment signal to the control chip according to the gear set by the user; the control chip receives the gear adjustment signal and calculates the corresponding conduction angle range; and the control chip adjusts the voltage output to the temperature control and gear adjustment circuit according to the corresponding conduction angle range in different voltage ranges to realize temperature control and gear adjustment. The present application simplifies the circuit structure, reduces the working cost, and improves the convenience of the user's temperature control and gear adjustment process.

Description

Technical Field

[0001] The present invention relates to the technical field of hot pressing welding, and in particular to a temperature control method and circuit for hot pressing welding. Background Art

[0002] The heating principle of a pulsed hot press welder is to utilize a high pulsed current flowing through high-resistance materials such as molybdenum and titanium to generate heat energy. This heat is then transferred to the workpiece in contact with the workpiece. The pulsed current heater provides instantaneous heating. A thermocouple connected to the front end of the nozzle monitors the nozzle temperature. Temperature regulation is achieved by controlling the output power. An automated control switch precisely controls the hot press welder's start and stop. Welding is initiated when the workpiece requires heating, and the nozzle temperature is controlled according to the desired temperature curve.

[0003] Hot-bar welding machines typically use a thyristor output connected to a multi-winding power-frequency transformer, which steps down the voltage before applying it to the high-resistance metal. Power regulation is achieved by controlling the thyristor conduction angle. Because the high-resistance metal being heated has a low resistance, a step-down transformer is required to reduce the grid voltage to 1-5V, generating a high current of several hundred amperes. A voltage range switch, mounted on the machine's operating panel, selects the turns ratio of the multi-winding transformer.

[0004] This multi-winding transformer combined with thyristor power regulation method and circuit has good temperature control effects. However, the multi-winding transformer is expensive and bulky, and requires a gear regulator, resulting in high overall cost. Therefore, the gear adjustment and temperature control method and circuit for hot pressing welding need to be improved to simplify the circuit structure, reduce operating costs, and improve the convenience of the gear adjustment and temperature control process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to improve the temperature control method and circuit of hot pressing welding so as to simplify the circuit structure, reduce the working cost and improve the convenience of the temperature control process.

[0006] In a first aspect, the present invention provides a temperature control method for hot pressing welding, wherein the temperature control method is applied to a temperature control system, wherein the temperature control system includes a temperature control circuit, a control chip, and a temperature control switch. The control chip establishes communication connections with the temperature control circuit and the temperature control switch to realize signal and data information transmission. The temperature control method includes:

[0007] The gear adjustment control switch outputs a matching gear adjustment signal to the control chip according to the gear position set by the user;

[0008] The control chip receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal;

[0009] The control chip adjusts the voltage output to the gear adjustment and temperature control circuit within different voltage ranges according to the corresponding conduction angle range to achieve temperature control and gear adjustment.

[0010] Preferably, the gear adjustment and temperature control system is connected to a display to realize the transmission of signals and data information, the display is used to display a monitoring interface, and the gear adjustment control switch outputs a matching gear adjustment signal to the control chip according to the gear position set by the user, including:

[0011] Displaying the data information in the gear adjustment control switch on the monitoring interface to form a gear adjustment area for receiving user input information; the gear adjustment control switch includes a plurality of preset gears;

[0012] Matching the corresponding gear position among the plurality of preset gear positions according to user input information;

[0013] Different levels of output voltage are matched according to the corresponding gears.

[0014] Preferably, before the control chip receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal, it further includes:

[0015] If an input sampled workpiece temperature is received, the sampled workpiece temperature is compared with a preset temperature to obtain an error value;

[0016] The error value is input into a preset operation model for operation to obtain an output value; the operation model is composed of a proportional unit, an integral unit and a differential unit;

[0017] The conduction angle is obtained by conversion; the conduction angle is π minus the output value.

[0018] Preferably, the control chip receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal, including:

[0019] The control chip continuously receives the current temperature value input under the corresponding gear;

[0020] Continuously inputting a plurality of the current temperature values ​​into the calculation model for calculation to obtain a plurality of the conduction angles;

[0021] The corresponding conduction angle range is obtained by combining the plurality of conduction angles.

[0022] Preferably, the control chip adjusts the voltage output to the gear adjustment and temperature control circuit within different voltage ranges according to the corresponding conduction angle range, including:

[0023] The control chip receives the input sampled grid voltage and obtains the grid phase through a phase-locked algorithm;

[0024] The output port of the control chip is controlled to drive within the corresponding conduction angle range, and the driving is stopped at π and 2π, thereby turning on the gear adjustment and temperature control circuit to achieve the adjustment of the output voltage.

[0025] Preferably, the gear adjustment control switch is preset with one to five gears.

[0026] In a second aspect, an embodiment of the present invention provides a gear adjustment and temperature control circuit for hot pressing welding, wherein the gear adjustment and temperature control circuit uses the steps of the gear adjustment and temperature control method as described in any embodiment of the first aspect above, and the gear adjustment and temperature control circuit includes a power grid, an anti-parallel thyristor, an industrial frequency transformer and a resistor; the two ends of the power grid are respectively connected to the input end of the anti-parallel thyristor and the second pin of the industrial frequency transformer, and the output end of the anti-parallel thyristor is connected to the first pin of the industrial frequency transformer, and the third pin and the fourth pin of the industrial frequency transformer are respectively connected to the two ends of the resistor.

[0027] Preferably, the anti-parallel thyristor includes a first unidirectional thyristor and a second unidirectional thyristor, the anode of the first unidirectional thyristor is connected to the cathode of the second unidirectional thyristor to form a first connection point, the power grid is connected to the first connection point, the cathode of the first unidirectional thyristor is connected to the anode of the second unidirectional thyristor to form a second connection point, the first pin of the power frequency transformer is connected to the second connection point, and the control electrode of the first unidirectional thyristor and the control electrode of the second unidirectional thyristor are respectively connected to the control chip.

[0028] Compared with the prior art, the present invention has at least one of the following beneficial technical effects:

[0029] The temperature control circuit includes an electrical grid, an anti-parallel thyristor, an industrial frequency transformer, and a resistor. The two ends of the electrical grid are connected to the input of the anti-parallel thyristor and the second pin of the industrial frequency transformer, respectively. The output of the anti-parallel thyristor is connected to the first pin of the industrial frequency transformer, and the third pin and the third pin of the industrial frequency transformer are connected to the two ends of the resistor. The temperature control method is applied to a control system of the temperature control circuit, specifically comprising: a temperature control switch outputs a matching temperature control signal to a control chip according to a user-set temperature; the control chip receives the temperature control signal and calculates the conduction angle range corresponding to the temperature control signal; the control chip adjusts the voltage output to the temperature control circuit within different voltage ranges according to the corresponding conduction angle range to achieve temperature control and temperature adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a circuit schematic diagram of the gear adjustment and temperature control circuit provided in an embodiment of the present invention.

[0032] Figure 2 A flow chart of the temperature control method according to an embodiment of the present invention.

[0033] Figure 3 A schematic diagram of an application scenario of the gear adjustment and temperature control method provided in an embodiment of the present invention.

[0034] Figure 4 A schematic diagram of a sub-process of the gear adjustment and temperature control method provided in an embodiment of the present invention.

[0035] Figure 5 A schematic diagram of another sub-process of the gear adjustment and temperature control method provided in an embodiment of the present invention.

[0036] Figure 6 A schematic diagram of another sub-process of the gear adjustment and temperature control method provided in an embodiment of the present invention.

[0037] Figure 7 A schematic diagram of another sub-process of the gear adjustment and temperature control method provided in an embodiment of the present invention.

[0038] Explanation of the accompanying symbols: G, power grid; T1, first unidirectional thyristor; T2, second unidirectional thyristor; T, power frequency transformer; R, resistor; 10, gear adjustment and temperature control system; 11, gear adjustment and temperature control circuit; 12, control chip; 13, gear adjustment and control switch. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0041] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0042] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0043] In order to solve the problem of high cost and large size of multi-winding transformers in the prior art, a gear regulator needs to be added, which leads to high overall cost and complicated gear adjustment and temperature control process. The embodiment of the present invention provides a gear adjustment and temperature control circuit for hot pressing welding. Figure 1 , Figure 1 This is a circuit schematic diagram of the gear adjustment and temperature control circuit provided in an embodiment of the present invention.

[0044] The gear-adjusting and temperature-controlling circuit includes a power grid G, an anti-parallel thyristor, an industrial frequency transformer T, and a resistor R, wherein the industrial frequency transformer T has a first pin, a second pin, a third pin, and a fourth pin. Specifically, the power grid G ​​is a single-phase power grid, the positive pole of the power grid G ​​is connected to the input end of the anti-parallel thyristor, the negative pole of the power grid G ​​is connected to the second pin of the industrial frequency transformer T, and the output end of the anti-parallel thyristor is connected to the first pin of the industrial frequency transformer T, and the third pin and the fourth pin of the industrial frequency transformer T are respectively connected to the two ends of the resistor R. Here, the resistor R is the workpiece to be heated, and the hot pressing welding is performed by heating the resistor R. Compared with the existing temperature control circuit, the gear-adjusting and temperature-controlling circuit removes the multi-winding transformer and the winding gear switch, and only retains the industrial frequency transformer T with the highest voltage output, and achieves the purpose of adjusting the output voltage within different voltage ranges by limiting the range of the conduction angle.

[0045] Furthermore, the anti-parallel thyristor includes a first unidirectional thyristor T1 and a second unidirectional thyristor T2. The anode of the first unidirectional thyristor T1 is connected to the cathode of the second unidirectional thyristor T2 to form a first connection point, which is the input terminal of the anti-parallel thyristor. The positive electrode of the power grid G ​​is connected to the first connection point. The cathode of the first unidirectional thyristor T1 is connected to the anode of the second unidirectional thyristor T2 to form a second connection point, which is the output terminal of the anti-parallel thyristor. The first pin of the power frequency transformer T is connected to the second connection point. The control electrode of the first unidirectional thyristor T1 and the control electrode of the second unidirectional thyristor T2 are respectively connected to a control chip to control the switching of the first unidirectional thyristor T1 and the second unidirectional thyristor T2.

[0046] On the other hand, the embodiment of the present invention provides a method for adjusting the temperature of hot pressing welding, which optimizes the existing method to simplify the circuit structure, reduce the working cost, and improve the convenience of the user's adjustment process. Figure 2 and Figure 3 , Figure 2 This is a flow chart of the temperature control method according to an embodiment of the present invention. Figure 3 Schematic diagram of an application scenario of the gear adjustment and temperature control method provided in an embodiment of the present invention.

[0047] In this embodiment, the gear adjustment and temperature control method is applied to a gear adjustment and temperature control system 10. The gear adjustment and temperature control system 10 includes a gear adjustment and temperature control circuit 11, a control chip 12, and a gear adjustment and control switch 13. The control chip 12 establishes communication connections with the gear adjustment and temperature control circuit 11 and the gear adjustment and control switch 13 to realize the transmission of signals and data information. The specific implementation process of the gear adjustment and temperature control method provided by the embodiment of the present invention is described in detail below. Figure 2 As shown, the method includes steps S110 to S130.

[0048] S110 , the gear adjustment control switch 13 outputs a matching gear adjustment signal to the control chip 12 according to the gear position set by the user.

[0049] See also Figure 4 In a specific embodiment, the gear shifting and temperature control system 10 is connected to a display to realize the transmission of signals and data information. The display is used to display a monitoring interface. Step S110 includes the following steps: S111, displaying the data information in the gear shifting and temperature control switch 13 on the monitoring interface to form a gear control area for receiving user input information; the user's input information can be the actual required output voltage value, the sampled workpiece temperature, the actual required temperature value, etc.; the gear shifting and temperature control switch 13 includes multiple preset gears; S112, matching the corresponding gears in the multiple preset gears according to the user input information; S113, matching different levels of output voltage according to the corresponding gears.

[0050] In order to achieve the purpose of voltage regulation, this embodiment adds a gear adjustment control switch 13 to the monitoring interface. In this embodiment, the preset gears of the gear adjustment control switch 13 are one to five gears, specifically one gear, two gears, three gears, four gears and five gears. The gear adjustment temperature control system 10 matches the corresponding gear of the gear adjustment control switch 13 preset in the system according to the user's input information.

[0051] S120, the control chip 12 receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal.

[0052] See also Figure 5In a specific embodiment, before step S120, the following steps are also included: S101. If the input sampled workpiece temperature is received, the sampled workpiece temperature is compared with the preset temperature to obtain an error value; S102. The error value is input into a preset operation model for operation to obtain an output value β; the operation model is composed of a proportional unit, an integral unit and a differential unit; S103. The conduction angle is obtained by conversion; the conduction angle is π minus the output value: α=π-β.

[0053] Here, the operation model is the PID controller, which is set by three parameters: the proportional parameter (Kp) of the proportional unit, the integral parameter (Ki) of the integral unit, and the differential parameter (Kd) of the differential unit. The PID controller is mainly suitable for systems with basic linearity and dynamic characteristics that do not change with time.

[0054] See also Figure 6 In a specific embodiment, step S120 includes the following steps: S121, the control chip 12 continuously receives the current temperature value input under the corresponding gear; S122, continuously inputs multiple current temperature values ​​into the calculation model for calculation to obtain multiple conduction angles; S123, integrates multiple conduction angles to obtain the corresponding conduction angle range.

[0055] S130, the control chip 12 adjusts the voltage output to the gear adjustment and temperature control circuit 11 within different voltage ranges according to the corresponding conduction angle range to achieve temperature control and gear adjustment.

[0056] See also Figure 7 In a specific embodiment, step S130 includes the following steps: S131, the control chip 12 receives the input sampled grid voltage and obtains the grid phase through a phase-locked algorithm; S132, controls the output port of the control chip 12 to drive within the corresponding conduction angle range, and stops driving at π and 2π, thereby turning on the gear adjustment and temperature control circuit 11 to achieve regulation of the output voltage.

[0057] Specifically, this embodiment calculates the effective value of the output voltage through an equation:

[0058]

[0059] The rated voltage of the grid is The positive conduction angle is α, and the negative conduction angle is α+π. The conduction angle refers to the angle at which the power electronic device (such as a thyristor) controls its conduction within one cycle. By controlling the conduction angle of the thyristor, the output voltage and current can be controlled. The conduction angle is 0 degrees from negative to positive zero crossing, and 180 degrees from positive to negative zero crossing. It can be seen that the conduction angle range is 0<α<π. As the α angle increases, the output effective value of the output voltage decreases. Conversely, as the α angle decreases, the output effective value of the output voltage increases. When α=0, the output voltage effective value U0 is the maximum, which is equal to the rated voltage effective value U. When α=π, the output voltage effective value is 0. The gear adjustment setting of the gear adjustment control switch 13 determines the maximum voltage value. Adjusting the conduction angle α realizes adjustment from the voltage 0V to the maximum voltage value range, and ultimately achieves the purpose of temperature control.

[0060] For example, when the output voltage RMS is 1V and the rated voltage RMS is 5V, the output voltage RMS is 0.2 times the rated voltage RMS, and π is 3.1416. According to the above equation, we can get:

[0061]

[0062] Since the conduction angle α ranges from 0 < α < π, we can substitute values ​​using a digital signal processing model (MATLAB) to obtain a value of 0.81318π. When α = 0.81318π, the output voltage RMS value is 1 V. Therefore, when controlling the positive conduction angle between 0.8132π and π, and the negative conduction angle between 1.8132π and 2π, the output voltage RMS value can be adjusted between 0 and 1 V. Similarly, the ranges for the other four conduction angles α can be obtained, which are integrated into the conduction angle α ranges shown in the table below.

[0063] Output voltage Voltage regulation range Alpha range 1V 0～1V Positive conduction angle: 0.8132π~π; negative conduction angle: 1.8132π~2π 2V 0～2V Positive conduction angle: 0.6915π~π; negative conduction angle: 1.6915π~π 3V 0～3V Positive conduction angle: 0.5711π~π; negative conduction angle: 1.5711π~π 4V 0～4V Positive conduction angle: 0.4288π~π; negative conduction angle: 1.4288π~π 5V 0～5V Positive conduction angle: 0~π; negative conduction angle: π~2π

[0064] Since the control chip 12 samples the grid voltage and obtains the phase of the grid through the phase-locked algorithm, and then obtains the conduction angle α according to the calculation model, the output port of the control chip 12 can be used to drive at the conduction angles α and α+π respectively, and stop driving at π and 2π, thereby realizing the conduction of the thyristor in the two intervals of α~π and (α+π)~2π, thereby realizing the adjustment of the output voltage and the control of the temperature.

[0065] The implementation principle of a gear adjustment and temperature control method and circuit for hot pressing welding according to an embodiment of the present invention is as follows: the gear adjustment and temperature control circuit 11 includes a power grid G, an anti-parallel thyristor, an industrial frequency transformer T, and a resistor R; the two ends of the power grid G ​​are respectively connected to the input end of the anti-parallel thyristor and the second pin of the industrial frequency transformer T, and the output end of the anti-parallel thyristor is connected to the first pin of the industrial frequency transformer T, and the third pin and the third pin of the industrial frequency transformer T are respectively connected to the two ends of the resistor R. The gear adjustment and temperature control method is applied to a gear adjustment and temperature control system 10, specifically including: the gear adjustment control switch 13 outputs a matching gear adjustment signal to the control chip 12 according to the gear set by the user; the control chip 12 receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal; the control chip 12 adjusts the voltage output to the gear adjustment and temperature control circuit 11 within different voltage ranges according to the corresponding conduction angle range to achieve temperature control and gear adjustment.

[0066] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for adjusting temperature and controlling the temperature of hot pressing welding, the method being applied to a temperature-adjusting control system, the temperature-adjusting control system comprising a temperature-adjusting circuit, a control chip and a temperature-adjusting control switch, the control chip establishing communication connections with the temperature-adjusting circuit and the temperature-adjusting control switch to achieve transmission of signals and data information, the temperature-adjusting control system being connected to a display to achieve transmission of signals and data information, the display being used to display a monitoring interface; the temperature-adjusting circuit comprising a power grid, an anti-parallel thyristor, an industrial frequency transformer and a resistor, the two ends of the power grid being respectively connected to the input end of the anti-parallel thyristor and the second pin of the industrial frequency transformer, and the output end of the anti-parallel thyristor being connected to the first pin of the industrial frequency transformer, the third pin and the fourth pin of the industrial frequency transformer being respectively connected to the two ends of the resistor, characterized in that: The gear adjustment control switch outputs a matching gear adjustment signal to the control chip according to the gear position set by the user; The control chip receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal; The control chip adjusts the voltage output to the gear adjustment and temperature control circuit within different voltage ranges according to the corresponding conduction angle range to achieve temperature control and gear adjustment; The gear adjustment control switch outputs a matching gear adjustment signal to the control chip according to the gear position set by the user, which specifically includes: Displaying the data information in the gear adjustment control switch on the monitoring interface to form a gear adjustment area for receiving user input information; the gear adjustment control switch includes a plurality of preset gears; Matching a corresponding gear position among the plurality of preset gear positions according to user input information; Matching different levels of output voltage according to the corresponding gears; Before the control chip receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal, the control chip further includes: If an input sampled workpiece temperature is received, the sampled workpiece temperature is compared with a preset temperature to obtain an error value; The error value is input into a preset operation model for operation to obtain an output value; the operation model is composed of a proportional unit, an integral unit and a differential unit; The conduction angle is obtained by conversion; the conduction angle is π minus the output value.

2. A method for adjusting temperature and controlling heat pressure welding according to claim 1, characterized in that: The control chip receives the gear adjustment signal and calculates the conduction angle range corresponding to the gear adjustment signal, including: The control chip continuously receives the current temperature value input under the corresponding gear; Continuously inputting a plurality of the current temperature values ​​into the calculation model for calculation to obtain a plurality of the conduction angles; The corresponding conduction angle range is obtained by combining the plurality of conduction angles.

3. The method for adjusting the temperature of hot pressing welding according to claim 1, characterized in that: The control chip adjusts the voltage output to the gear adjustment and temperature control circuit within different voltage ranges according to the corresponding conduction angle range, including: The control chip receives the input sampled grid voltage and obtains the grid phase through a phase-locked algorithm; The output port of the control chip is controlled to drive within the corresponding conduction angle range, and the driving is stopped at π and 2π, thereby turning on the gear adjustment and temperature control circuit to achieve the adjustment of the output voltage.

4. The method for adjusting temperature and controlling heat pressure welding according to claim 1, wherein: The gear adjustment control switch is preset to have one to five gears.

5. The method for adjusting temperature and controlling temperature for hot pressing welding according to claim 1, characterized in that: The anti-parallel thyristor includes a first unidirectional thyristor and a second unidirectional thyristor, the anode of the first unidirectional thyristor is connected to the cathode of the second unidirectional thyristor to form a first connection point, the power grid is connected to the first connection point, the cathode of the first unidirectional thyristor is connected to the anode of the second unidirectional thyristor to form a second connection point, the first pin of the power frequency transformer is connected to the second connection point, and the control electrode of the first unidirectional thyristor and the control electrode of the second unidirectional thyristor are respectively connected to the control chip.

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