A dual-mode driving modification method for a commercial vehicle with a drive air conditioner

Abstract

This invention relates to a method for retrofitting a commercial vehicle's belt-driven air conditioning system to a dual-mode system, addressing the problems inherent in the current market's primary "dual-system parallel" approach for handling vehicle parking cooling needs. The steps include: (a) removing the original belt-driven compressor from the vehicle's air conditioning system while retaining other components; (b) embedding a permanent magnet synchronous motor drive module, enabling the compressor to switch to AC power drive mode when the engine is off, thus forming a dual-mode compressor capable of both belt and electric drive; connecting it in series with the original air conditioning components to form an air conditioning circuit; (c) providing an electric drive controller and wiring harness, the controller converting AC power into the required voltage to power the dual-mode compressor and the original vehicle air conditioning system; and (d) electrically matching the wiring harness with the original vehicle air conditioning wiring harness and allowing for external AC power connection. This invention achieves seamless switching of the air conditioning system between driving and parking conditions through the dual-mode drive retrofit of the belt-driven air conditioning system.

Description

Technical Field

[0001] This invention relates to a method for retrofitting a commercial vehicle with a dual-mode drive system for air conditioning, belonging to the field of commercial vehicles. Background Technology

[0002] With the development of automotive technology and the increasing demand for user comfort, in-vehicle air conditioning has evolved from an optional feature to a core subsystem of vehicles. Its role in regulating cabin temperature and humidity, and filtering air impurities has become increasingly prominent, greatly enhancing driving and passenger comfort. Especially in extreme weather conditions, it not only affects the driving experience but also directly impacts driving safety and work efficiency.

[0003] Trucks, especially special-purpose vehicles, have unique and widespread requirements for air conditioning cooling when parked. Most automotive air conditioners on the market are belt-driven, and when parked, the air conditioning stops operating as soon as the engine stops, forcing the driver to keep the engine running. This not only makes it difficult to achieve ideal cooling performance and wastes energy, but also causes engine noise and vehicle vibration, affecting the rest and work experience of passengers. Currently, the market mainly addresses the parking cooling needs with a "dual-system parallel" solution, which involves adding a roof-mounted independent air conditioner or a household inverter air conditioner to the original vehicle air conditioning system. However, this solution has many drawbacks: roof-mounted air conditioners occupy the sunroof, increase the vehicle's drag coefficient, reduce fuel economy, and are inconvenient to maintain; household air conditioners have a high failure rate, take up space, and have poor reliability and durability. These technical bottlenecks have created an urgent need for innovative modifications to traditional air conditioning systems. Summary of the Invention

[0004] This invention provides a method for retrofitting a commercial vehicle's belt-driven air conditioning system to a dual-mode drive system. Based on the expansion of compressor functionality, it retains the original belt-driven architecture while embedding a permanent magnet synchronous motor drive module, allowing the compressor to switch to AC power drive mode when the engine is off. This type of compressor, capable of both belt-driven and electric drive, is called a dual-drive compressor or dual-mode compressor. By retrofitting the belt-driven air conditioning system to a dual-mode drive system, seamless switching between driving and parking conditions is achieved. When driving, the air conditioning system is driven by engine power; when parked, it is driven by AC power or a superstructure power supply, achieving efficient cooling under all operating conditions. This overcomes the limitations of existing air conditioning systems and provides a feasible and economical solution for optimizing and upgrading truck air conditioning systems.

[0005] This invention is achieved through the following technical solutions:

[0006] A method for retrofitting a commercial vehicle with dual-mode drive for air conditioning includes the following steps:

[0007] (a) The original driven compressor of the original vehicle air conditioner is removed, while other components of the original vehicle air conditioner are retained;

[0008] (b) An embedded permanent magnet synchronous motor drive module is provided, which enables the compressor to switch to mains power drive mode when the engine is stopped, thereby forming a dual-mode compressor. The dual-mode compressor can be driven by both belt and electricity. The dual-mode compressor is externally equipped with an electromagnetic clutch, which can connect or disconnect the power transmission between the engine and the dual-mode compressor as needed, so as to start and stop the dual-mode compressor.

[0009] (c) Provide an electric drive controller and connecting wiring harness. The electric drive controller converts the mains power into the required voltage to power the dual-mode compressor and the original vehicle air conditioning system.

[0010] (d) A dual-mode compressor replaces the original belt-driven compressor and is connected in series with the original air conditioning components to form an air conditioning circuit;

[0011] (e) The wiring harness is electrically matched with the original vehicle air conditioning wiring harness and can be connected to an external AC power supply to realize the electrical conversion of the air conditioning under driving / parking conditions.

[0012] Furthermore, the dual-mode compressor features a pressure plate-type inlet and outlet.

[0013] Furthermore, the dual-mode compressor utilizes a scroll structure to compress the refrigerant. Its components include pulleys, a clutch, a housing, a rotor, a stator, a stationary scroll, and a moving scroll, with the stationary and moving scrolls meshing together. Externally, the dual-mode compressor retains pulleys, using an engine to drive a belt for power transmission. Internally, a permanent magnet synchronous motor is used, relying on mains power for driving force. Both the pulleys and the motor drive the compressor's main shaft, which in turn rotates the moving scroll, thus compressing the refrigerant. Low-pressure gaseous refrigerant is drawn in from the outside of the stationary scroll, while the moving scroll revolves with the main shaft. During this process, the refrigerant is compressed within the crescent-shaped space formed by the stationary and moving scrolls, becoming high-pressure gaseous refrigerant, which is discharged from the center of the stationary scroll, then leaves the compressor and enters the condenser.

[0014] Furthermore, the electric drive controller includes a housing, a display screen, a connector, and buttons. The housing draws power from the mains or superstructure and performs voltage conversion to power the air conditioning system after the dual-mode drive modification. The mains or superstructure power is AC220V / DC220V / AC380V, and the voltage is converted. The converted output voltage is DC320V, which powers the dual-mode compressor in mains drive mode; the converted output voltage is DC28V, which connects to the original vehicle air conditioning wiring harness and powers the various components of the original vehicle air conditioning; and the converted output voltage is DC24V, which powers the dual-mode compressor clutch in mechanical drive mode. The electric drive controller has a start button on its body to control the opening and closing of the electric drive controller. The electric drive controller has a synchronous control interface that can connect to the wiring harness and a rocker switch. The rocker switch is fixed on the vehicle dashboard to realize remote control of the opening and closing of the electric drive controller by operating the rocker switch. The electric drive controller has a digital display screen that displays the output voltage in real time. The displayed voltage includes the DC320V voltage for the dual-mode compressor and the DC28V voltage for powering the original vehicle air conditioning components.

[0015] Furthermore, the electric drive controller has protective measures including leakage current protection, insulation protection, and grounding protection to mitigate safety risks.

[0016] Furthermore, the electric drive controller is equipped with power protectors at both the input and output ends. The input end has over / under voltage protection and leakage protection functions. When the leakage current exceeds 30mA, it actively cuts off the current input for protection. The DC output end is constant voltage and constant current and has short circuit protection. The voltage output interface of the electric drive controller uses an aviation-grade circular electrical connector, whose voltage withstand and insulation resistance specifications meet the usage requirements. The electric drive controller is equipped with a grounding post to connect to the cab or frame, forming a low-impedance path. The voltage regulator control board inside the electric drive controller is potted and encapsulated to ensure that the insulation resistance and withstand voltage values ​​meet the design requirements. The cables connecting to the electric drive controller are all covered with an electromagnetic shielding layer to prevent high-voltage and low-voltage lines from interfering with each other and to prevent electromagnetic interference and radiation from harming personnel. The cables are further encased in insulating corrugated tubing to prevent leakage caused by damage to the cable insulation layer. All insulating corrugated tubing uses closed-end plastic corrugated tubing, and high-voltage output cables are distinguished by orange corrugated tubing for warning purposes.

[0017] The modified electrical matching meets the following requirements:

[0018] First, the modified air conditioning electrical system has no impact on the overall vehicle electrical system;

[0019] Second, the operation method and control logic of the modified air conditioner remain unchanged.

[0020] Third, the pressure and temperature protection functions of the modified air conditioner remain unchanged;

[0021] Fourth, the modified air conditioner can switch freely between mechanical drive mode and AC drive mode, and the two modes cannot coexist or interfere with each other.

[0022] Furthermore, the vehicle's electrical system is matched:

[0023] After the dual-mode drive modification, the power supply for the air conditioning system in mechanical drive mode is provided by the vehicle battery, while the power supply in mains power drive mode is provided by mains power or the superstructure power supply.

[0024] The electric drive controller only supplies power to the air conditioning system, does not charge the vehicle battery, and does not supply power to other devices, so it has no impact on the vehicle's electrical performance.

[0025] Furthermore, the frost protection function is matched with:

[0026] After the dual-mode drive modification, the frost protection function of the air conditioning system remains consistent with the control logic of the original vehicle air conditioning. That is, in mechanical drive mode, the frost protection function is executed according to the original vehicle air conditioning control logic; in AC drive mode, the electric drive controller collects the signal from the temperature sensor inside the evaporator and controls the operation and stop of the motor drive module inside the dual-mode compressor, thereby realizing the frost protection function.

[0027] Furthermore, the air conditioner A / C switch is interlocked:

[0028] After the dual-mode drive modification, no new control panel is added; the original vehicle air conditioning control panel is still used. The A / C switch cannot simultaneously control the dual-mode compressor clutch in AC power drive mode, thus forming an interlock design. The interlock design logic of the air conditioning A / C switch is as follows:

[0029] (1) In mechanical drive mode, the A / C switch is still used to control the on and off of the dual-mode compressor clutch; when the A / C switch button is pressed, the A / C light is lit, the dual-mode compressor clutch is engaged, and the engine power is transmitted to the dual-mode compressor pulley via belt drive, which drives the main shaft and scroll plate to rotate and work, so as to achieve the cooling effect; when the cab temperature reaches the set temperature, the A / C switch automatically stops outputting and the dual-mode compressor clutch is disconnected.

[0030] (2) In the mains power drive mode, the dual-mode compressor clutch is in the normally open state, and the A / C switch controls the operation and stop of the dual-mode compressor; when the A / C switch button is pressed, the A / C light is lit, the internal motor drive module of the dual-mode compressor starts, and drives the main shaft and scroll plate of the dual-mode compressor to rotate; when the cab temperature reaches the set temperature, the A / C switch automatically stops outputting, and the internal motor drive module of the dual-mode compressor stops working.

[0031] (3) Although the control points of the A / C switch are different in mechanical drive mode and AC drive mode, they both control the cooling output and stop.

[0032] (4) Under the condition that both mechanical drive mode and AC drive mode are satisfied, the air conditioning system shall give priority to AC drive mode.

[0033] Furthermore, the method for implementing the air conditioning A / C switch interlock logic is as follows: add an electric drive controller, fuse box, and related wiring harness to the original vehicle air conditioning electrical system; add an electric drive controller to power the air conditioning system after the dual-mode drive modification; add a fuse box between the electric drive controller and the original vehicle air conditioning wiring harness; the fuse box achieves the above control logic by connecting the original vehicle air conditioning wiring harness and adding related relays and fuses.

[0034] The fuse box contains three fuses and three relays;

[0035] All three fuses are 20A. The first fuse protects the evaporator fan, the second protects the condenser fan, and the third protects the dual-mode compressor signal control and fuse box power supply.

[0036] All three relays are square, 5-pin, 40A. Relay 1 supplies power to the compressor clutch in mechanical drive mode and disconnects the power supply in AC drive mode. Relay 2 supplies power to the condenser fan. In both mechanical and AC drive modes, the relay is activated to supply power to the condenser fan when the A / C switch is turned on. Relay 3 is used for converting the A / C signal output of the air conditioning control panel. In mechanical drive mode, the A / C output of the control panel is negative, which is converted to positive by relay 3 to supply power to the dual-mode compressor clutch.

[0037] Furthermore, the control of the dual-mode compressor after the dual-mode drive modification:

[0038] Mechanical drive mode: When the vehicle starts, the engine power drives the dual-mode compressor pulley to rotate via belt. At this time, the dual-mode compressor pulley is idling. When the control panel A / C outputs a signal, the A / C signal output is negative. After being converted to positive by relay No. 3, the positive A / C signal is output to the normally closed pin 87a via the common pin 30 of relay No. 1 to supply power to the dual-mode compressor clutch. At this time, the outer disc of the clutch engages with the pulley, and the pulley drives the main shaft to rotate. The main shaft then drives the moving scroll to rotate and compress the gaseous refrigerant, and the dual-mode compressor begins to cool. When the A / C switch stops outputting a signal, the clutch is de-energized, the outer disc of the clutch separates from the pulley, the power is cut off, the main shaft and the moving scroll no longer rotate, the dual-mode compressor stops cooling, and the dual-mode compressor pulley is idling.

[0039] AC power drive mode: When AC power is input, the electromagnetic coil of relay No. 1 is turned on, the connection between common pin 30 and normally closed pin 87a is disconnected, and common pin 30 and normally open pin 87a are turned on, providing a start signal to the dual-mode compressor AC power drive mode. As long as there is AC power input, the air conditioner will use AC power drive mode for cooling.

[0040] This invention, through a dual-mode drive modification of the original vehicle's air conditioning power system, successfully enables the system to achieve cooling capabilities under both driving and parking conditions. This modification scheme fully utilizes most of the original vehicle's air conditioning components, requires minimal alteration to the original vehicle structure, and possesses significant advantages and high feasibility. After multiple rounds of testing and comparative analysis, the results show that the dual-mode drive air conditioning system exhibits excellent cooling performance, meets the expected design requirements, aligns with market demands, provides users with a superior comfort experience, and demonstrates greater application value in related fields.

[0041] Compared to the traditional "dual-system parallel" solution, this invention adds an independent parking air conditioning system. The dual-mode drive modification solution requires minimal changes to the original vehicle structure, can reuse most of the original vehicle parts, has low cost, and simplifies the operation process through centralized control. Attached Figure Description

[0042] Figure 1 shows the original vehicle air conditioning power system before and after the commercial vehicle modification according to the present invention, where a is before modification and b is after modification;

[0043] Figure 2 This is a schematic diagram of the compressor's appearance, where a is the original vehicle compressor with drive, and b is the dual-mode compressor;

[0044] Figure 3 This is a schematic diagram of the internal structure of the dual-mode compressor of the present invention;

[0045] Figure 4 This is a control diagram of the dual-mode compressor after the dual-mode drive modification;

[0046] Figure 5 This is the schematic diagram of the square 5-pin relay of the present invention;

[0047] Figure 6 This is the original vehicle air conditioning electrical schematic diagram;

[0048] Figure 7 This is the electrical schematic diagram after the dual-mode drive modification. The solid red lines represent newly added fuses, and the dashed red lines represent newly added relays. Detailed Implementation

[0049] As shown in Figures 1 and 2, this invention provides a method and application for retrofitting a commercial vehicle's onboard air conditioning system with a belt drive. This method is used to modify the original onboard air conditioning power system of a commercial vehicle, enabling two working modes: belt drive during driving and AC power drive during parking. The method includes the following steps: (a) removing the original belt-driven compressor of the onboard air conditioning system while retaining other components; (b) providing a dual-mode compressor that can be driven by both belt and electricity; (c) providing an electric drive controller and wiring harness, which converts AC power into the required voltage to power the dual-mode compressor and the original onboard air conditioning system; (d) replacing the original belt-driven compressor with the dual-mode compressor and connecting it in series with the original air conditioning components to form an air conditioning circuit; (e) electrically matching the wiring harness with the original air conditioning wiring harness and allowing connection to an external AC power source to achieve electrical switching between driving and parking conditions.

[0050] I. Structure and Performance Advantages of Dual-Mode Compressor

[0051] Appearance and Structure: Compared to the original vehicle's belt-driven compressor, the dual-mode compressor is larger and longer, primarily due to the addition of an internal electric drive module and an external integrated electronic control module. Simultaneously, the dual-mode compressor has a relatively smaller pulley size, increasing the transmission ratio to fully utilize the compressor's high-speed advantage, enabling efficient operation at commonly used speeds and thus extending its service life. Regarding the intake and exhaust port design, the original vehicle's belt-driven compressor uses threaded connectors, while the dual-mode compressor uses pressure plate type intake and exhaust ports. This design simplifies and speeds up installation. Figure 2 As shown.

[0052] Internal Structure: The dual-mode compressor utilizes a scroll structure to compress the refrigerant. Its main components include pulleys, clutches, housing, rotor, stator, stationary scroll, and moving scroll. Externally, the dual-mode compressor retains pulleys, using an engine to drive a belt for power transmission; internally, it employs a permanent magnet synchronous motor, powered by AC mains electricity. Both the pulleys and the motor drive the compressor's main shaft, which in turn rotates the moving scroll, thus compressing the refrigerant. Low-pressure gaseous refrigerant is drawn in from the outside of the stationary scroll. The moving scroll revolves with the main shaft, compressing the refrigerant within the crescent-shaped space formed by the stationary and moving scrolls. After compression, it becomes high-pressure gaseous refrigerant, exiting from the center of the stationary scroll, then leaving the compressor and entering the condenser. Figure 3 As shown.

[0053] Performance Advantages: Compared to the original vehicle's belt-driven compressor, the dual-mode compressor uses a method of interlocking moving and stationary scrolls to compress gas. This compressor method makes the gas compression process not only more continuous and stable, but also results in less compression vibration and lower noise during operation, providing a more stable cooling output for the system. Furthermore, due to minimal internal leakage, the dual-mode compressor achieves a volumetric efficiency of over 90%, demonstrating superior compression efficiency. The original vehicle's belt-driven compressor is a swashplate compressor, where components such as the piston and connecting rod experience significant wear during high-speed reciprocating motion. In contrast, the dual-mode compressor has a lower relative sliding speed between the moving and stationary scrolls, resulting in less wear and thus a longer service life.

[0054] II. Electric Drive Controller Design

[0055] The air conditioner requires mains power or a power supply from the superstructure to operate in AC power mode. Since different components of the air conditioner require different voltages, an electric drive controller is added. The electric drive controller mainly consists of a housing, display screen, connector, and buttons. The housing is made of aluminum alloy using CNC machining. Its main function is to draw power from the mains or superstructure and convert the voltage to power the air conditioning system after the dual-mode drive modification. The electric drive controller draws power from the superstructure, which can be AC220V / DC220V / AC380V, and converts the voltage. The converted output voltage is DC320V, which powers the dual-mode compressor in AC power mode; DC28V, which connects to the original vehicle air conditioning wiring harness and powers the original vehicle air conditioning components; and DC24V, which powers the dual-mode compressor clutch in mechanical drive mode. The electric drive controller has a start button on its body to control its on / off operation. The electric drive controller has a synchronous control interface, which can connect to wiring harnesses and rocker switches. The rocker switch can be fixed to the vehicle's dashboard, allowing remote control of the electric drive controller's on / off operation. The controller itself has a digital display screen with real-time output voltage display, showing voltages including the DC 320V voltage for the dual-mode compressor and the DC 28V voltage for powering the original vehicle air conditioning components. Because the electric drive controller uses high-voltage electricity, multiple protections are implemented for electrical safety. Safety risks are identified from the design stage and mitigated through leakage protection, insulation, and grounding measures. The main protection measures are as follows: The electric drive controller has power protectors at both the input and output ends. The input end has over / under voltage protection and leakage protection functions. When the leakage current exceeds 30mA, the current input is actively cut off for protection. The DC output end is constant voltage and constant current, with short-circuit protection. The voltage output interface of the electric drive controller uses an aerospace-grade circular electrical connector, which has advantages such as quick connection and disconnection, good environmental resistance, and high reliability. Its voltage resistance and insulation resistance specifications meet the usage requirements. The electric drive controller is equipped with a grounding post, connected to the cab or chassis, forming a low-impedance path to prevent damage to personnel and equipment in case of leakage. The voltage regulator control board inside the electric drive controller is encapsulated with potting compound to ensure that the insulation resistance and withstand voltage meet design requirements. All cables connecting to the electric drive controller are wrapped with an electromagnetic shielding layer to prevent interference between high-voltage and low-voltage lines and to prevent electromagnetic interference and radiation from harming personnel. The cables are further encased in insulating corrugated tubing to prevent leakage caused by damage to the cable insulation. To prevent dust and moisture from entering the corrugated tubing and creating safety hazards, all insulating corrugated tubing is closed-end plastic corrugated tubing, with orange corrugated tubing used for high-voltage output cables for identification and warning purposes.

[0056] III. Electrical Matching

[0057] The key to the dual-mode drive retrofit of commercial vehicle air conditioning power systems lies in electrical matching. The first requirement is that the modified air conditioning electrical system should have minimal impact on the overall vehicle electrical system; the second is that the operation method and control logic of the modified air conditioning should remain as unchanged as possible; the third is that the pressure and temperature protection functions of the modified air conditioning should remain as unchanged as possible; and the fourth is that the modified air conditioning should be able to switch freely between mechanical drive mode and AC drive mode, and the two modes should not coexist or interfere with each other. Figure 6 , 7 As shown.

[0058] Vehicle electrical matching: Before the dual-mode drive modification, the air conditioning system was powered by the vehicle battery;

[0059] After the dual-mode drive modification, the power for the air conditioning system in mechanical drive mode is provided by the vehicle's battery, while in AC drive mode, the power is provided by AC power or the superstructure power supply.

[0060] For electrical safety reasons, the electric drive controller only supplies power to the air conditioning system, does not charge the vehicle battery, and does not supply power to other devices, so it has no impact on the vehicle's electrical performance.

[0061] Frost protection function matching:

[0062] The evaporator frosting protection function is an automatic protection mechanism designed to address the issue of frost formation on the evaporator surface in cooling mode. It uses real-time temperature monitoring to detect abnormally low evaporator temperatures and triggers the compressor to stop, preventing the frosting from worsening. The aim is to prevent performance degradation or equipment damage caused by abnormal frosting. When the evaporator core is frosted, the frost blocks the surface, reducing airflow and cooling efficiency. The original vehicle air conditioning system has a frosting protection function: when the temperature sensor detects that the evaporator core surface temperature is below 1.2°C, the system actively disengages the compressor clutch. Once the blower raises the evaporator core surface temperature to 3.5°C, the system re-engages the compressor clutch. After the dual-mode drive modification, the air conditioning system's frosting protection function remains consistent with the original vehicle air conditioning control logic. In mechanical drive mode, the frosting protection function is executed according to the original vehicle air conditioning control logic; in AC drive mode, the electric drive controller collects signals from the evaporator's internal temperature sensor and controls the operation and shutdown of the dual-mode compressor's internal motor drive module, thus achieving the frosting protection function.

[0063] Air conditioner A / C switch interlock design:

[0064] The original vehicle air conditioning control panel has an A / C switch used to control the clutch of the original driven compressor. After the dual-mode drive modification, no new control panel will be added; the original vehicle air conditioning control panel will still be used. If the dual-mode compressor clutch is engaged in AC power drive mode, the simultaneous operation of mechanical drive mode and AC power drive mode will damage the dual-mode compressor. Therefore, the A / C switch should not simultaneously control the dual-mode compressor clutch in AC power drive mode, forming an interlock design. The interlock design logic of the air conditioning A / C switch is as follows:

[0065] (1) In mechanical drive mode, the A / C switch is still used to control the on / off state of the dual-mode compressor clutch. When the A / C switch button is pressed, the A / C light illuminates, the dual-mode compressor clutch engages, and the engine power is transmitted to the dual-mode compressor pulley via belt drive, driving the main shaft and scroll plate to rotate and achieve the cooling effect. When the cab temperature reaches the set temperature, the A / C switch automatically stops outputting, and the dual-mode compressor clutch disengages.

[0066] (2) In mains power drive mode, the dual-mode compressor clutch is normally open, and the A / C switch controls the operation and stop of the dual-mode compressor. Pressing the A / C switch button illuminates the A / C light, and the internal motor drive module of the dual-mode compressor starts, driving the main shaft and scroll plate of the dual-mode compressor to rotate. When the cab temperature reaches the set temperature, the A / C switch automatically stops outputting, and the internal motor drive module of the dual-mode compressor stops working.

[0067] (3) Although the control points of the A / C switch are different in mechanical drive mode and AC drive mode, they both control the cooling output and stop.

[0068] (4) Under the condition that both mechanical drive mode and AC drive mode are satisfied, the air conditioning system shall give priority to AC drive mode.

[0069] To implement the above control logic, the original vehicle air conditioning electrical system is modified to include an electric drive controller, fuse box, and related wiring harnesses. The electric drive controller provides power to the modified dual-mode air conditioning system. A fuse box is added between the electric drive controller and the original vehicle air conditioning wiring harness. This fuse box connects to the original vehicle air conditioning wiring harness and includes relevant relays and fuses to achieve the above control logic.

[0070] like Figure 4 , 5 As shown in Figures 6 and 7, the fuse box contains 3 fuses and 3 relays.

[0071] All three fuses are 20A. The first fuse protects the evaporator fan (blower), the second protects the condenser fan, and the third protects the dual-mode compressor signal control and the power supply to the fuse box.

[0072] All three relays are square, 5-pin, 40A. Relay 1 supplies power to the compressor clutch in mechanical drive mode and disconnects the power supply in AC drive mode. Relay 2 supplies power to the condenser fan. In both mechanical and AC drive modes, the relay is activated to supply power to the condenser fan when the A / C switch is turned on. Relay 3 is used for converting the A / C signal output of the air conditioning control panel. In mechanical drive mode, the A / C output of the control panel is negative, which is converted to positive by relay 3 to supply power to the dual-mode compressor clutch.

[0073] The control of the dual-mode compressor after dual-mode drive modification is as follows: Figure 4 , 5 As shown in 6 and 7:

[0074] Mechanical Drive Mode: When the vehicle starts, the engine power drives the dual-mode compressor pulley to rotate via a belt. At this time, the dual-mode compressor pulley idles. When the A / C control panel outputs a signal (the A / C signal is negative), it is converted to positive via relay #3. The positive A / C signal is then output to the dual-mode compressor clutch via pin 30 of relay #1, connected to pin 87a. The clutch outer disc engages with the pulley, driving the main shaft to rotate. The main shaft then drives the rotating scroll to compress the gaseous refrigerant, and the dual-mode compressor begins cooling operation. When the A / C switch stops outputting a signal, the clutch is de-energized, the clutch outer disc separates from the pulley, and the power is cut off. The main shaft and rotating scroll no longer rotate, the dual-mode compressor stops cooling, and the dual-mode compressor pulley idles.

[0075] AC power drive mode: When AC power is input, the electromagnetic coil of relay 1 is activated, disconnecting pins 30 and 87a, and activating pins 30 and 87, providing a start signal to the dual-mode compressor in AC power drive mode. Whenever AC power is input, the air conditioner prioritizes AC power drive mode for cooling. Figure 5 As shown.

[0076] Explanation: When the vehicle is running and the air conditioner is connected to AC power, the air conditioner prioritizes AC power drive mode for cooling. The engine drives the dual-mode compressor pulley to rotate, but relays 30 and 87a are in the open state. The dual-mode compressor clutch is not powered, and the clutch outer plate does not engage with the pulley. At this time, the pulley spins freely and does not drive the main shaft. The AC power is converted to DC 320V after passing through the electric drive controller and supplies voltage to the dual-mode compressor. The internal motor drive module of the dual-mode compressor starts working and drives the main shaft to rotate. The main shaft then drives the rotating scroll plate to rotate for cooling. At this time, the pulley is spinning freely, while the motor drive module is responsible for cooling. The two power sources are separate and do not interfere with each other. This will not cause damage to the dual-mode compressor due to simultaneous input of two power sources.

[0077] This invention has the following characteristics:

[0078] 1. The dual-mode compressor includes a pulley on the outside, which can be driven by the engine power using a transmission belt. The dual-mode compressor also includes an electromagnetic clutch on the outside, which can connect or disconnect the power transmission between the engine and the dual-mode compressor as needed, so as to start and stop the dual-mode compressor. The dual-mode compressor includes a permanent magnet synchronous motor inside, which allows the compressor to switch to mains power drive mode when the engine is stopped, so that the dual-mode compressor can be driven by mains power.

[0079] 2. After modification, the air conditioner can switch between mechanical drive mode and AC power drive mode at will, realizing seamless switching of the air conditioning system under driving and parking conditions. When driving, the air conditioner is driven by the engine power, and when parked, the air conditioner is driven by AC power or the superstructure power supply, realizing efficient cooling under all working conditions.

[0080] 3. After the modification, the air conditioner can switch between mechanical drive mode and AC drive mode, but the two modes will not exist at the same time, nor will they interfere with each other.

[0081] 4. The control panel and operation method of the air conditioner remain unchanged after the modification; the pressure and temperature protection functions of the air conditioner remain unchanged after the modification.

[0082] 5. A new electric drive controller is added to power the modified air conditioner, including power supply for the original vehicle air conditioner components, power supply for the dual-mode compressor motor drive module, and power supply for the dual-mode compressor clutch, etc.

[0083] 6. A new fuse box is added to connect to the original vehicle air conditioning wiring harness, and related relays and fuses are added to realize the switching control logic between mechanical drive mode and AC drive mode.

Claims

1. A method for retrofitting a commercial vehicle with dual-mode drive for air conditioning, characterized in that: Includes the following steps: (a) The original onboard compressor of the vehicle air conditioner is removed, while other components of the original vehicle air conditioner are retained; (b) An embedded permanent magnet synchronous motor drive module is provided, which enables the compressor to switch to mains power drive mode when the engine is stopped, thereby forming a dual-mode compressor. The dual-mode compressor can be driven by both belt and electricity. The dual-mode compressor is externally equipped with an electromagnetic clutch, which can connect or disconnect the power transmission between the engine and the dual-mode compressor as needed, so as to start and stop the dual-mode compressor. (c) Provide an electric drive controller and connecting wiring harness. The electric drive controller converts the mains power into the required voltage to power the dual-mode compressor and the original vehicle air conditioning system. (d) The dual-mode compressor replaces the original belt-driven compressor and is connected in series with the original air conditioning components to form an air conditioning circuit; (e) The wiring harness is electrically matched with the original vehicle air conditioning wiring harness and can be connected to an external mains power supply to realize the electrical conversion of the air conditioning under driving / parking conditions; The modified electrical matching meets the following requirements: 1) Vehicle electrical matching: After the dual-mode drive modification, the power supply for the air conditioning system in mechanical drive mode is provided by the vehicle battery, while the power supply in mains power drive mode is provided by mains power or the superstructure power supply. The electric drive controller only supplies power to the air conditioning system, does not charge the vehicle battery, and does not supply power to other devices, so it has no impact on the vehicle's electrical performance. 2) Frost protection function matching: After the dual-mode drive modification, the frost protection function of the air conditioning system remains consistent with the control logic of the original vehicle air conditioning. That is, in mechanical drive mode, the frost protection function is executed according to the original vehicle air conditioning control logic; in AC drive mode, the electric drive controller collects the signal from the temperature sensor inside the evaporator and controls the operation and stop of the motor drive module inside the dual-mode compressor, thereby realizing the frost protection function. 3) Air conditioner A / C switch interlock design: After the dual-mode drive modification, no new control panel is added; the original vehicle air conditioning control panel is still used. The A / C switch cannot simultaneously control the dual-mode compressor clutch in AC power drive mode, thus forming an interlock design. The interlock design logic of the air conditioning A / C switch is as follows: (1) In mechanical drive mode, the A / C switch is still used to control the on and off of the dual-mode compressor clutch; when the A / C switch button is pressed, the A / C light is lit, the dual-mode compressor clutch is engaged, and the engine power is transmitted to the dual-mode compressor pulley via belt drive, which drives the main shaft and scroll plate to rotate and work, so as to achieve the cooling effect; when the cab temperature reaches the set temperature, the A / C switch automatically stops outputting and the dual-mode compressor clutch is disconnected. (2) In mains power drive mode, the dual-mode compressor clutch is in a normally open state, and the A / C switch controls the operation and stop of the dual-mode compressor; Press the A / C switch button, the A / C light will illuminate, and the internal motor drive module of the dual-mode compressor will start, driving the main shaft and scroll plate of the dual-mode compressor to rotate. When the cab temperature reaches the set temperature, the A / C switch automatically stops outputting, and the internal motor drive module of the dual-mode compressor stops working; (3) Although the control points of the A / C switch are different in mechanical drive mode and AC drive mode, they both control the cooling output and stop; (4) Under the condition that both mechanical drive mode and AC drive mode are satisfied, the air conditioning system shall give priority to AC drive mode; The method to implement the air conditioning A / C switch interlock logic is as follows: add an electric drive controller, fuse box and related wiring harness to the original vehicle air conditioning electrical system; add an electric drive controller to power the air conditioning system after the dual-mode drive modification; add a fuse box between the electric drive controller and the original vehicle air conditioning wiring harness; the fuse box is connected to the original vehicle air conditioning wiring harness and related relays and fuses are added to realize the above control logic. The fuse box contains three fuses and three relays; All three fuses are 20A. The first fuse protects the evaporator fan, the second protects the condenser fan, and the third protects the dual-mode compressor signal control and fuse box power supply. All three relays are square, 5-pin, 40A. Relay 1 supplies power to the compressor clutch in mechanical drive mode and disconnects the power supply in AC drive mode. Relay 2 supplies power to the condenser fan. In both mechanical and AC drive modes, the relay is activated to supply power to the condenser fan when the A / C switch is turned on. Relay 3 is used for converting the A / C signal output of the air conditioning control panel. In mechanical drive mode, the A / C output of the control panel is negative, which is converted to positive by relay 3 to supply power to the dual-mode compressor clutch.

2. The method for retrofitting a commercial vehicle with dual-mode air conditioning according to claim 1, characterized in that: The dual-mode compressor has a pressure plate type inlet and outlet.

3. The method for retrofitting a commercial vehicle with dual-mode air conditioning according to claim 1, characterized in that: The dual-mode compressor uses a scroll structure to compress the refrigerant. Its components include pulleys, clutches, housing, rotor, stator, stationary scroll, and moving scroll, with the moving and stationary scrolls meshing with each other. Externally, the dual-mode compressor retains pulleys and uses an engine to drive a belt for power transmission. Internally, a permanent magnet synchronous motor is used, relying on mains power for driving force; both the pulley and the motor can drive the compressor's main shaft, which in turn drives the moving scroll to rotate, realizing the compression operation of the refrigerant; low-pressure gaseous refrigerant is drawn in from the outside of the stationary scroll, and the moving scroll revolves with the main shaft. During this process, the refrigerant is compressed in the crescent-shaped space formed by the moving and stationary scrolls, and after compression, it becomes high-pressure gaseous refrigerant, which is discharged from the center of the stationary scroll, and then leaves the compressor and enters the condenser.

4. The method for retrofitting a commercial vehicle with dual-mode air conditioning according to claim 1, characterized in that: The electric drive controller includes a housing, a display screen, a connector, and buttons. The housing draws power from the mains or superstructure and performs voltage conversion to power the air conditioning system after the dual-mode drive modification. The mains or superstructure power is AC220V / DC220V / AC380V, and the voltage is converted. The converted output voltage is DC320V, which powers the dual-mode compressor in mains drive mode; DC28V, which connects to the original vehicle air conditioning wiring harness and powers the various components of the original vehicle air conditioning; and DC24V, which powers the dual-mode compressor clutch in mechanical drive mode. The electric drive controller has a start button to control the opening and closing of the electric drive controller. The electric drive controller has a synchronous control interface that can connect the wiring harness and a rocker switch. The rocker switch can be fixed on the vehicle dashboard to remotely control the opening and closing of the electric drive controller. The electric drive controller has a digital display screen that displays the real-time output voltage, including the DC320V voltage for the dual-mode compressor and the DC28V voltage for powering the various components of the original vehicle air conditioning.

5. The method for retrofitting a commercial vehicle with dual-mode air conditioning according to claim 4, characterized in that: The electric drive controller has protective measures including leakage current protection, insulation protection, and grounding protection to avoid safety risks.

6. The method for retrofitting a commercial vehicle with dual-mode air conditioning according to claim 5, characterized in that: The electric drive controller is equipped with power protectors at both the input and output ends. The input end has over / under voltage protection and leakage protection functions. When the leakage current exceeds 30mA, it actively cuts off the current input for protection. The DC output end is constant voltage and constant current and has short circuit protection. The voltage output interface of the electric drive controller uses an aviation-grade circular electrical connector, and its voltage withstand and insulation resistance specifications meet the usage requirements. The electric drive controller is equipped with a grounding post to connect to the cab or frame, forming a low-impedance path. The voltage regulator control board inside the electric drive controller is potted and encapsulated to ensure that the insulation resistance and withstand voltage values ​​meet the design requirements. All cables connecting to the electric drive controller are covered with an electromagnetic shielding layer to prevent high-voltage and low-voltage lines from interfering with each other and to prevent electromagnetic interference and radiation from harming personnel. The cable is covered with an insulating corrugated tube to prevent leakage caused by damage to the cable insulation layer; all insulating corrugated tubes are closed plastic corrugated tubes, and orange corrugated tubes are used for high-voltage output cables to distinguish them and serve as a warning.

7. The method for retrofitting a commercial vehicle with dual-mode air conditioning according to claim 1, characterized in that: Control of the dual-mode compressor after dual-mode drive modification: Mechanical drive mode: When the vehicle starts, the engine power drives the dual-mode compressor pulley to rotate via belt. At this time, the dual-mode compressor pulley is idling. When the control panel A / C outputs a signal, the A / C signal is negative. After being converted to positive by relay No. 3, the positive A / C signal is output to the dual-mode compressor clutch via the common pin of relay No. 1 and connected to the normally closed pin. At this time, the outer disc of the clutch engages with the pulley, and the pulley drives the main shaft to rotate. The main shaft then drives the moving scroll to rotate and compress the gaseous refrigerant, and the dual-mode compressor begins to cool. When the A / C switch stops outputting a signal, the clutch is de-energized, the outer disc of the clutch separates from the pulley, the power is cut off, the main shaft and the moving scroll no longer rotate, the dual-mode compressor stops cooling, and the dual-mode compressor pulley is idling. AC power drive mode: When AC power is input, the electromagnetic coil of relay No. 1 is activated, the connection between the common pin and the normally closed pin is disconnected, and the common pin and the normally open pin are connected to provide a start signal for the AC power drive mode of the dual-mode compressor. As long as there is AC power input, the air conditioner will use AC power drive mode for cooling first.

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