Band saw machine independent cooling water circulation and water pump motor protection control circuit

Abstract

The application belongs to the technical field of mechatronics electrical control, and is a band saw machine independent cooling water circulation and water pump motor protection control circuit, which comprises a main power supply with an output of 380V alternating current, a voltage conversion module for converting 380V three-phase alternating current into 24V direct current, a sawing motor, a water pump motor, a water pump motor protection module, a sawing control circuit, a water pump control circuit and a water pump control bypass; the output end of the main power supply is electrically connected with the sawing motor, the voltage conversion module and the water pump motor protection module respectively; the 24V direct current output end of the voltage conversion module is connected with the sawing control circuit, the water pump control circuit and the water pump control bypass respectively; the sawing control circuit controls the start and stop of the sawing motor; and the water pump control circuit and the water pump control bypass independently control the start and stop of the water pump motor respectively.

Description

Technical Field

[0001] This invention belongs to the field of mechatronics electrical control technology, specifically relating to an independent cooling water circulation and water pump motor protection control circuit applied to a metal processing band saw. Background Technology

[0002] Band saws are the core equipment for metal profile cutting and processing. The operational stability of their cooling system directly determines the sawing accuracy, saw blade lifespan, and overall equipment reliability.

[0003] Existing band saws generally adopt a linkage control mode between the sawing motor and the water pump motor. When the sawing motor starts, the water pump motor runs synchronously, and when the sawing motor stops, the water pump motor stops synchronously. In low-temperature environments (ambient temperature below 0℃), the water in the cooling pipes becomes stagnant after the water pump stops, making it very prone to freezing. This can lead to pipe freezing and cracking, water circuit blockage, and other malfunctions, causing the equipment to malfunction and significantly increasing the frequency of equipment maintenance and operating costs.

[0004] Currently, most industry solutions for cooling pipe antifreeze involve mechanical antifreeze structures such as adding insulated enclosures, electric heating tapes, and external electric heaters. These solutions are passive antifreeze methods, resulting in high equipment modification costs, significant maintenance workload, and an inability to address the core issue of cooling water freezing at a static state from the control logic level. Consequently, their antifreeze stability and adaptability are poor.

[0005] Meanwhile, the existing electrical protection system for band saws only has overcurrent protection mechanisms for the sawing motor, and no dedicated protection circuit is configured for the water pump motor. During operation, the water pump motor is prone to overload current due to conditions such as pipe blockage, motor stall, abnormal load, and short circuit. Due to the lack of a dedicated protection mechanism, the water pump motor is very easy to burn out, directly causing the cooling system and antifreeze function to fail, which seriously affects the continuous and stable operation of the band saw.

[0006] In summary, the existing band saw cooling control circuit has technical defects such as poor low-temperature antifreeze effect, lack of dedicated protection for water pump motor, and high operation and maintenance costs, and urgently needs to be optimized and improved. Summary of the Invention

[0007] The technical problem this invention aims to solve is to overcome the shortcomings of existing band saws, such as the easy freezing of cooling pipes at low temperatures and the lack of dedicated protection for water pump motors, which are prone to burnout. This invention provides an independent cooling water circulation and water pump motor protection control circuit for band saws. By reconstructing the circuit control logic, this invention enables the water pump motor to operate independently and continuously after the sawing motor stops, fundamentally solving the problem of freezing in low-temperature pipes. Simultaneously, it incorporates a dedicated water pump motor overcurrent protection module with adjustable threshold values, achieving precise overload protection for the water pump motor, reducing equipment failure rates and maintenance costs, and improving the band saw's adaptability and operational reliability in low-temperature environments.

[0008] The technical solution adopted in this invention is: an independent cooling water circulation and water pump motor protection control circuit for a band saw, including a main power supply (1) with an output of 380V AC, a transformer module (2) that converts 380V three-phase AC to 24V DC, a sawing motor (3), a water pump motor (4), a water pump motor protection module (5), a sawing control circuit (6), a water pump control circuit (7), and a water pump control bypass (8); the output terminal of the main power supply (1) is electrically connected to the sawing motor (3), the transformer module (2), and the water pump motor protection module (5), respectively, and the 24V DC output terminal of the transformer module (2) is connected to the sawing control circuit (6) and the water pump control circuit (7), respectively. The sawing control circuit (6) controls the start and stop of the sawing motor (3), and the water pump control circuit (7) and the water pump control bypass (8) independently control the start and stop of the water pump motor (4). The water pump control bypass (8) is independent of the linkage logic of the sawing control circuit (6) and can continue to maintain the operation of the water pump motor (4) after the sawing motor (3) stops, so as to realize the uninterrupted independent circulation of cooling water. The water pump motor protection module (5) is arranged in series in the power supply circuit of the water pump motor (4). The water pump motor protection module (5) is equipped with an adjustable current protection threshold, which is used to accurately protect the water pump motor (4) from overload and stall faults during operation. The input terminal of the transformer module is connected to the main power supply and can convert 380V AC power to 24V DC power to provide a safe low-voltage control power supply for each control circuit, so as to realize the electrical isolation between the power supply and the control power supply.

[0009] The sawing control circuit (6) and the water pump control circuit (7) form an electrical interlock control structure. When the sawing motor (3) starts running, the water pump control circuit (7) is synchronously turned on, so that the water pump motor (4) and the sawing motor (3) start and stop synchronously to meet the cooling requirements of the sawing operation.

[0010] The water pump motor protection module (5) detects the working current of the water pump motor (4) in real time. When the working current exceeds the preset protection threshold, it automatically cuts off the power supply circuit of the water pump motor (4) to achieve power failure protection.

[0011] The sawing control circuit (6) includes a first start button (SB1), a first stop button (SB3), a first AC contactor (KM1), and a self-locking circuit. When the first start button (SB1) is pressed, the first AC contactor (KM1) is energized and latches itself, driving the sawing motor (3) to run stably. When the first stop button (SB3) is pressed, the first AC contactor (KM1) is de-energized and released, and the sawing motor (3) stops running.

[0012] The water pump control circuit (7) is equipped with a second AC contactor (KM2). The auxiliary contact of the first AC contactor (KM1) is linked to the coil of the second AC contactor (KM2). When the sawing motor (3) is running, the second AC contactor (KM2) is synchronously engaged and turned on, driving the water pump motor (4) to run synchronously.

[0013] The water pump control bypass (8) includes a second start button (SB2), a second stop button (SB4), and a third AC contactor (KM3). The contacts of the third AC contactor (KM3) are connected in parallel with the coil circuit of the second AC contactor (KM2). The water pump motor (4) can be independently started and stopped by the second start button (SB2) and the second stop button (SB4), thus breaking away from the linkage logic of the sawing motor (3).

[0014] The beneficial effects of this invention are: it eliminates the problem of low-temperature pipeline freezing. This invention adds an independent water pump control bypass, breaking the traditional linkage logic of synchronous start-stop between the sawing motor and the water pump motor. After the sawing operation ends and the sawing motor stops, the water pump motor can run independently and continuously, ensuring that the cooling water is always in dynamic circulation. It eliminates the need for external mechanical anti-freeze structures such as heating, insulation, and heat tracing, solving the problems of cooling water freezing and pipeline cracking at the root of the control logic, and significantly reducing equipment modification and subsequent maintenance costs.

[0015] This invention achieves dedicated and precise protection for the water pump motor. An independent, adjustable overcurrent protection module is installed in the water pump motor's power supply circuit to monitor the motor's operating current in real time. It can quickly cut off power in abnormal operating conditions such as motor overload, stall, and short circuit, effectively preventing the water pump motor from burning out, ensuring the continuous and stable operation of the cooling system, and significantly improving the overall reliability of the band saw.

[0016] This invention is highly versatile and adaptable. The current threshold of the water pump motor protection module can be flexibly adjusted to adapt to water pump motors with different rated power without modifying the main circuit structure. It can be applied to the circuit assembly of brand-new band saws as well as to the electrical retrofitting of existing old band saws, making it suitable for a wide range of scenarios.

[0017] This invention is safe to operate and convenient and reliable. Electrical isolation between 380V power and 24V control power is achieved through a transformer module, reducing the risk of electric shock during equipment operation. The equipment retains the original conventional operating logic, adds an independent water pump control link, and features a simple operation method that aligns with industrial field work habits, making it highly practical. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall circuit structure of the present invention; Figure 2 This is a power supply block diagram of the transformer module of the present invention; Figure 3This is a schematic diagram of the control loop connection structure of the present invention; Figure 4 This is a schematic diagram showing the connection of the sawing motor, water pump motor, and protection module of the present invention.

[0019] Among them, 1-main power supply, 2-transformer module, 3-sawing motor, 4-water pump motor, 5-water pump motor protection module, 6-sawing motor control circuit, 7-water pump motor control circuit, 8-water pump motor control bypass; SB1-first start button, SB2-second start button, SB3-first stop button, SB4-second stop button; KM1-first AC contactor, KM2-second AC contactor, KM3-third AC contactor. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail and completely below with reference to the accompanying drawings. These embodiments are only used to explain the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] like Figure 1 As shown, in this embodiment, the main power supply 1 outputs 380V AC power to provide power to the transformer module 2, the sawing motor 3, and the water pump motor protection module 5.

[0022] Transformer module 2 converts the input 380V AC power into 24V DC power, providing a stable low-voltage control power supply for sawing motor control circuit 6, water pump motor control circuit 7, and water pump motor control bypass 8.

[0023] The sawing motor control circuit 6 is used to control the start and stop operation of the sawing motor 3. The water pump motor control circuit 7 and the water pump motor control bypass 8 work together to control the working status of the water pump motor 4. The water pump motor protection module 5 is connected in series in the main power supply circuit of the water pump motor 4 to realize full-process fault monitoring and protection.

[0024] like Figure 2 As shown, the output terminal of the main power supply 1 is electrically connected to the input terminal of the transformer module 2. The transformer module 2 completes the conversion of 380V high-voltage AC power to 24V low-voltage DC power, providing a safe and stable working power supply for each control circuit, realizing the separation of strong and weak currents in the equipment, and improving the safety of circuit operation.

[0025] like Figure 3 As shown, the sawing motor control circuit 6 consists of SB1, SB3, KM1, and a self-locking circuit. During operation, pressing SB1 energizes the KM1 coil, causing it to engage. Figure 4 As shown, when the main contact of KM1 is closed, the sawing motor 3 starts running. At the same time, the normally open auxiliary contact of KM1 closes to achieve self-locking, ensuring that the sawing motor 3 continues to work stably. When SB3 is pressed, the KM1 coil is de-energized and released, the main contact opens, and the sawing motor 3 stops running.

[0026] The water pump motor control circuit 7 and the sawing motor control circuit 6 form an electrical interlock: the auxiliary normally open contact of KM1 is connected in series in the coil circuit of KM2. After the sawing motor 3 starts, the auxiliary contact of KM1 closes synchronously, the coil of KM2 is energized and attracted, the main contact of KM2 is turned on, and the water pump motor 4 starts running synchronously to meet the real-time cooling requirements of the sawing operation.

[0027] The water pump motor control bypass 8 consists of SB2, SB4, and KM3. The main contact of KM3 is connected in parallel with the coil circuit of KM2 and is not subject to the logic constraints of the KM1 contact. After the sawing operation is completed in a low-temperature environment, pressing SB3 stops the sawing motor 3, the auxiliary contact of KM1 opens, and the linkage of the water pump motor control circuit 7 fails. At this time, pressing SB2 energizes the KM3 coil, and the main contact of KM3 remains conductive, providing a stable power supply to the KM2 coil, allowing the water pump motor 4 to continue running, ensuring the circulation of water in the cooling pipes and preventing freezing at low temperatures. After all operations are completed, pressing SB4 de-energizes the KM3 coil, and the water pump motor 4 stops completely.

[0028] like Figure 4 As shown, the water pump motor protection module 5 is connected in series in the main power supply circuit of the water pump motor 4. Before using the equipment, the operator adjusts the current protection threshold of the water pump motor protection module 5 according to the rated current parameters of the water pump motor 4. During equipment operation, the water pump motor protection module 5 dynamically collects the operating current of the water pump motor 4 in real time. When faults such as pipeline blockage, motor stall, abnormal load, or short circuit occur, causing the operating current of the water pump motor 4 to exceed the preset threshold, the water pump motor protection module 5 immediately cuts off the power supply circuit, and the water pump motor 4 stops in an emergency, effectively preventing motor burnout and achieving reliable overload protection.

[0029] The circuit structure of this embodiment is simple, easy to modify, and stable in operation. It can be widely used in various metal processing band saws, effectively solving the technical problems of low-temperature freezing pipes and easy damage to water pump motors. It has high industrial application value.

Claims

1. A band saw independent cooling water circulation and water pump motor protection control circuit, comprising a main power supply (1) outputting 380V AC, a transformer module (2) converting 380V three-phase AC to 24V DC, a sawing motor (3), a water pump motor (4), a water pump motor protection module (5), a sawing control circuit (6), a water pump control circuit (7), and a water pump control bypass (8); the output terminal of the main power supply (1) is electrically connected to the sawing motor (3), the transformer module (2), and the water pump motor protection module (5), respectively, and the 24V DC output terminal of the transformer module (2) is connected to the sawing control circuit (6), the water pump control circuit (7), and the water pump control bypass (8), characterized in that: The sawing control circuit (6) controls the start and stop of the sawing motor (3). The water pump control circuit (7) and the water pump control bypass (8) independently control the start and stop of the water pump motor (4). The water pump control bypass (8) is independent of the linkage logic of the sawing control circuit (6) and can continue to maintain the operation of the water pump motor (4) after the sawing motor (3) stops, so as to realize the uninterrupted independent circulation of cooling water. The water pump motor protection module (5) is arranged in series in the power supply circuit of the water pump motor (4). The water pump motor protection module (5) is equipped with an adjustable current protection threshold, which is used to accurately protect the water pump motor (4) from overload and stall faults during operation.

2. The independent cooling water circulation and water pump motor protection control circuit for the band saw as described in claim 1, characterized in that, The sawing control circuit (6) and the water pump control circuit (7) form an electrical interlock control structure. When the sawing motor (3) starts running, the water pump control circuit (7) is synchronously turned on, so that the water pump motor (4) and the sawing motor (3) start and stop synchronously to meet the cooling requirements of the sawing operation.

3. The independent cooling water circulation and water pump motor protection control circuit for the band saw according to claim 1, characterized in that, The water pump motor protection module (5) detects the working current of the water pump motor (4) in real time. When the working current exceeds the preset protection threshold, it automatically cuts off the power supply circuit of the water pump motor (4) to achieve power failure protection.

4. The independent cooling water circulation and water pump motor protection control circuit for the band saw according to claim 2, characterized in that, The sawing control circuit (6) includes a first start button (SB1), a first stop button (SB3), a first AC contactor (KM1), and a self-locking circuit. When the first start button (SB1) is pressed, the first AC contactor (KM1) is energized and latches itself, driving the sawing motor (3) to run stably. When the first stop button (SB3) is pressed, the first AC contactor (KM1) is de-energized and released, and the sawing motor (3) stops running.

5. The independent cooling water circulation and water pump motor protection control circuit for band saws according to claim 4, characterized in that: The water pump control circuit (7) is equipped with a second AC contactor (KM2). The auxiliary contact of the first AC contactor (KM1) is linked to the coil of the second AC contactor (KM2). When the sawing motor (3) is running, the second AC contactor (KM2) is synchronously engaged and turned on, driving the water pump motor (4) to run synchronously.

6. The independent cooling water circulation and water pump motor protection control circuit for band saws according to claim 5, characterized in that: The water pump control bypass (8) includes a second start button (SB2), a second stop button (SB4), and a third AC contactor (KM3). The contacts of the third AC contactor (KM3) are connected in parallel with the coil circuit of the second AC contactor (KM2). The water pump motor (4) can be independently started and stopped by the second start button (SB2) and the second stop button (SB4), thus breaking away from the linkage logic of the sawing motor (3).

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