Sewing machine controller patch IGBT over-temperature protection structure

Abstract

This utility model belongs to the field of sewing machine technology, specifically referring to a surface-mount IGBT over-temperature protection structure for a sewing machine controller. It includes a PCB board, on which surface-mount IGBTs, surface-mount thermistors, and an MCU are mounted. The surface-mount IGBTs are attached to one side of the PCB board, and the surface-mount thermistors are attached to the other side. The MCU is electrically connected to both the surface-mount IGBTs and the surface-mount thermistors. The surface-mount IGBTs are electrically connected to a stepper motor. This utility model occupies little space, is suitable for scenarios with limited space, and has wide applicability.

Description

Technical fields:

[0001] This utility model belongs to the field of sewing machine technology, specifically referring to a sewing machine controller patch IGBT over-temperature protection structure. Background technology:

[0002] Currently, many sewing machines use stepper motors instead of mechanical parts to achieve functions such as stitch length adjustment and presser foot lifting. Stepper motors are controlled by sewing machine controllers, and the power devices that drive stepper motors often use high-voltage IGBTs. Especially when multiple stepper motors need to be driven, the controller space is limited, and IGBTs are often surface-mount packaged to compress space. In comparison, the heat dissipation capacity will decrease, leading to overheating and damage of the IGBTs during use.

[0003] Currently, most controllers do not monitor the temperature of surface-mount IGBTs, making them prone to overheating and damage during use, thus shortening the controller's lifespan. Some controllers use additional temperature sensors to detect surface-mount IGBT issues, but these require significant space and are unsuitable for space-constrained applications, resulting in limited applicability. Summary of the Invention:

[0004] The purpose of this invention is to provide a sewing machine controller patch IGBT over-temperature protection structure, which occupies little space, is suitable for scenarios with limited space, and has wide applicability.

[0005] This utility model is implemented as follows:

[0006] A sewing machine controller surface-mount IGBT over-temperature protection structure includes a PCB board. The PCB board is provided with a surface-mount IGBT, a surface-mount thermistor, and an MCU. The surface-mount IGBT is attached to one side of the PCB board, and the surface-mount thermistor is attached to the other side of the PCB board. The MCU is electrically connected to the surface-mount IGBT and the surface-mount thermistor respectively. The surface-mount IGBT is electrically connected to a stepper motor.

[0007] In the above-mentioned over-temperature protection structure for a sewing machine controller surface-mount IGBT, the surface-mount IGBT can be mounted on the PCB board by reflow soldering or hot air soldering.

[0008] In the above-mentioned over-temperature protection structure for a sewing machine controller surface-mount IGBT, the surface-mount IGBT can also be mounted by pressing it onto the PCB board.

[0009] In the above-mentioned sewing machine controller surface-mount IGBT over-temperature protection structure, the surface-mount thermistor can be mounted by reflow soldering or hot air soldering onto the PCB board.

[0010] In the above-mentioned sewing machine controller surface-mount IGBT over-temperature protection structure, the surface-mount thermistor can also be mounted by pressing it onto the PCB board.

[0011] In the above-mentioned over-temperature protection structure for a sewing machine controller surface-mount IGBT, the surface-mount thermistor is located at the position corresponding to the middle of the surface-mount IGBT.

[0012] In the above-mentioned over-temperature protection structure of a sewing machine controller patch IGBT, there are two or more patch IGBTs arranged in an array to form an IGBT patch group, and the patch thermistor is located at the corresponding position in the middle of the IGBT patch group.

[0013] In the above-mentioned over-temperature protection structure of a surface-mount IGBT for a sewing machine controller, the PCB board is also provided with a voltage divider resistor connected in series with the surface-mount thermistor.

[0014] In the above-mentioned over-temperature protection structure of a sewing machine controller surface-mount IGBT, one end of the voltage divider resistor is electrically connected to the positive terminal of the power supply, and the other end is electrically connected to one end of the surface-mount thermistor. The other end of the surface-mount thermistor is grounded, and the end of the voltage divider resistor connected to the surface-mount thermistor is also electrically connected to the MCU.

[0015] In the above-mentioned over-temperature protection structure of a sewing machine controller surface-mount IGBT, the MCU and the voltage divider resistor are disposed on the side of the PCB board on which the surface-mount thermistor is attached.

[0016] The outstanding advantages of this utility model compared to the prior art are:

[0017] 1. This utility model uses a surface-mount thermistor to sense the temperature of a surface-mount IGBT, which occupies little space and is suitable for scenarios with limited space, making it widely applicable. Simultaneously, the surface-mount thermistor is used, with the surface-mount IGBT and the thermistor respectively attached to opposite sides of the PCB board, effectively transferring the heat from the surface-mount IGBT to the thermistor via the PCB board. This results in good heat conduction and easy installation. Furthermore, the MCU receives resistance changes from the surface-mount thermistor to control the output, effectively protecting the surface-mount IGBT while also improving stitch length response, stitch length holding, and step-by-step presser foot / seam micro-lift response speed, thus enhancing the customer's sewing results.

[0018] 2. The present invention provides two or more surface-mount IGBTs arranged in an array to form an IGBT surface-mount group. The surface-mount thermistor is located at the corresponding position in the middle of the IGBT surface-mount group. The heat of the surface-mount IGBT is effectively conducted to the surface-mount thermistor, and the surface-mount thermistor can better sense the temperature of the surface-mount IGBT. Attached image description:

[0019] Figure 1 This is the circuit diagram of this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of this utility model.

[0021] Reference numerals in the attached diagram: 1. PCB board; 2. Surface mount IGBT; 3. Surface mount thermistor; 4. MCU; 5. Stepper motor; 6. Voltage divider resistor. Detailed implementation method:

[0022] The present invention will be further described below with reference to specific embodiments. See also: Figure 1 —2:

[0023] A sewing machine controller surface-mount IGBT over-temperature protection structure includes a PCB board 1. The PCB board 1 is provided with a surface-mount IGBT 2, a surface-mount thermistor 3, and an MCU 4. The surface-mount IGBT 2 is attached to one side of the PCB board 1, and the surface-mount thermistor 3 is attached to the other side of the PCB board 1. The MCU 4 is electrically connected to the surface-mount IGBT 2 and the surface-mount thermistor 3 respectively. The surface-mount IGBT 2 is electrically connected to a stepper motor 5.

[0024] The working principle of this utility model is as follows: Figure 1 , 2 As shown, when the surface-mount IGBT2 drives the stepper motor 5, the surface-mount IGBT2, as a power switching device, generates a large amount of heat. Since the PCB board 1 is a good heat conductor, the heat generated by the surface-mount IGBT2 on one side of the PCB board 1 is effectively conducted through the PCB board 1 to the surface-mount thermistor 3 on the other side of the PCB board 1. The surface-mount thermistor 3 senses the conducted heat and generates a change in resistance. The change in resistance of the surface-mount thermistor 3 is transmitted to the MCU4 for detection. The MCU4 converts the change in resistance into a temperature value and determines whether it is over-temperature based on the over-temperature protection threshold preset by the MCU4. If it is over-temperature, over-temperature protection is performed.

[0025] If MCU4 detects that the temperature of the surface-mount IGBT2 exceeds the preset over-temperature protection threshold, MCU4 will reduce the output duty cycle (i.e., reduce the output current to the stepper motor 5) or shut down the control output signal to the surface-mount IGBT2 to reduce damage to the surface-mount IGBT2 caused by overheating.

[0026] If the MCU4 detects that the temperature of the surface-mount IGBT2 is within the safe temperature range, the MCU4 can output a larger duty cycle (i.e., increase the output current of the stepper motor 5), thereby improving the stepper control stitch length response, stitch length holding, and stepper presser foot / seam lift response speed, thus improving the customer's sewing effect.

[0027] This invention uses a surface-mount thermistor 3 to sense the temperature of the surface-mount IGBT 2, occupying little space and suitable for scenarios with limited space, thus having wide applicability. Simultaneously, the surface-mount thermistor is used, with the surface-mount IGBT 2 and the surface-mount thermistor 3 respectively attached to both sides of the PCB board 1, effectively conducting the heat of the surface-mount IGBT 2 to the surface-mount thermistor 3 via the PCB board 1, resulting in good heat conduction and easy installation. Furthermore, the MCU 4 receives the resistance change from the surface-mount thermistor 3 to control the output, effectively protecting the surface-mount IGBT 2 while also improving stitch length response, stitch length holding, and step-by-step presser foot / seam micro-lift response speed, thus enhancing the customer's sewing effect.

[0028] In this embodiment, the surface-mount IGBT 2 is soldered onto the PCB board 1 by reflow soldering or hot air soldering, and the surface-mount thermistor 3 is soldered onto the PCB board 1 by reflow soldering or hot air soldering, which is efficient and low cost.

[0029] In order to better conduct the heat of the surface mount IGBT2 to the surface mount thermistor 3, and to better sense the temperature of the surface mount IGBT2, the surface mount thermistor 3 is located at the position corresponding to the middle of the surface mount IGBT2.

[0030] To better conduct the heat from the surface-mount IGBT2 to the surface-mount thermistor 3, and to allow the surface-mount thermistor 3 to better sense the temperature of the surface-mount IGBT2, such as... Figure 2 As shown, there are two or more surface-mount IGBTs 2 arranged in an array to form an IGBT surface-mount group, and the surface-mount thermistor 3 is located at the corresponding position in the middle of the IGBT surface-mount group. In this embodiment, there are six surface-mount IGBTs 2 arranged in a 2x3 array, and the surface-mount thermistor 3 is located between two surface-mount IGBTs 2 at the second position from the top, as shown. Figure 2 As shown, the six rectangular frames in PCB board 1 are the mounting positions for the six surface-mount IGBT 2 modules.

[0031] Furthermore, the PCB board 1 is also provided with a voltage divider resistor 6 connected in series with the surface mount thermistor 3. The surface mount thermistor 3 and the voltage divider resistor 6 constitute a voltage detection circuit. The voltage detection signal is output to the MCU4, and the output signal of the MCU4 is connected to the surface mount IGBT2 to control the switching on and off of the surface mount IGBT2.

[0032] The specific connection method of the voltage divider resistor 6 is as follows: one end of the voltage divider resistor 6 is electrically connected to the positive terminal of the power supply, and the other end is electrically connected to one end of the surface mount thermistor 3. The other end of the surface mount thermistor 3 is grounded, and the end of the voltage divider resistor 6 connected to the surface mount thermistor 3 is also electrically connected to the MCU4.

[0033] Furthermore, the MCU4 and the voltage divider resistor 6 are disposed on the side of the PCB board 1 on which the surface-mount thermistor 3 is attached.

[0034] Furthermore, the PCB is a printed circuit board, the IGBT is an insulated gate bipolar transistor, and the MCU is a microcontroller unit.

[0035] This invention utilizes the excellent thermal conductivity of the PCB board 1. Only a small-package surface-mount thermistor 3 needs to be added. The surface-mount thermistor 3 senses the heat conducted from the PCB board 1 and generates a change in resistance. The temperature of the surface-mount IGBT 2 can be detected using a simple voltage divider detection method. The output current can be adjusted according to the preset temperature range of the MCU 4 to adjust the torque of the stepper motor. This improves the response speed of stepper stitch pitch adjustment, stitch pitch holding, and stepper presser foot / seam micro-lift response speed.

[0036] The above embodiments are only one of the preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes made in accordance with the shape, structure and principle of this utility model should be covered within the protection scope of this utility model.

Claims

1. A sewing machine controller patch IGBT over-temperature protection structure, characterized in that: The PCB board (1) includes a surface mount IGBT (2), a surface mount thermistor (3) and an MCU (4) on the PCB board (1). The surface mount IGBT (2) is attached to one side of the PCB board (1) and the surface mount thermistor (3) is attached to the other side of the PCB board (1). The MCU (4) is electrically connected to the surface mount IGBT (2) and the surface mount thermistor (3) respectively. The surface mount IGBT (2) is electrically connected to a stepper motor (5).

2. The over-temperature protection structure for a sewing machine controller patch IGBT according to claim 1, characterized in that: The surface mount thermistor (3) is located at the position corresponding to the middle of the surface mount IGBT (2).

3. The over-temperature protection structure for a sewing machine controller patch IGBT according to claim 1, characterized in that: The surface-mount IGBTs (2) are arranged in two or more arrays to form an IGBT surface-mount group, and the surface-mount thermistor (3) is located at the corresponding position in the middle of the IGBT surface-mount group.

4. The over-temperature protection structure for a sewing machine controller patch IGBT according to claim 1, characterized in that: The PCB board (1) is also provided with a voltage divider resistor (6) connected in series with the surface mount thermistor (3).

5. The over-temperature protection structure for a sewing machine controller patch IGBT according to claim 4, characterized in that: One end of the voltage divider resistor (6) is electrically connected to the positive terminal of the power supply, and the other end is electrically connected to one end of the surface mount thermistor (3). The other end of the surface mount thermistor (3) is grounded. The end of the voltage divider resistor (6) connected to the surface mount thermistor (3) is also electrically connected to the MCU (4).

6. The over-temperature protection structure for a sewing machine controller patch IGBT according to claim 4, characterized in that: The MCU (4) and the voltage divider resistor (6) are set on the side of the PCB board (1) where the surface mount thermistor (3) is attached.

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