Automatic gear shifting control system of pure electric two-gear type transfer case

Abstract

An automatic gear shifting control system of a pure electric two-gear type transfer case is arranged on a transfer case shell of the two-gear type transfer case and comprises a gear shifting driving device and a main control module. In the gear shifting driving device, an air path valve block is arranged on an air cylinder shell, an air path in the air path valve block is connected with a piston cavity in the air cylinder shell through a gear shifting electromagnetic valve, and an air pressure sensor is further arranged on the air path in the air path valve block. The air cylinder shell is provided with two piston cavities which are movably provided with a first-gear shifting fork shaft piston and a second-gear shifting fork shaft piston respectively, and position switches are arranged at the corresponding positions of the first-gear shifting fork shaft piston and the second-gear shifting fork shaft piston respectively. The gear shifting driving device is connected with the main control module through a cable connector; the main control module comprises a control unit, a main control module cable, an input speed sensor and an output speed sensor. The automatic gear shifting control device can achieve the automatic gear shifting control function in the traveling process of the two-gear type transfer case.

Description

Technical Field

[0001] This utility model belongs to the field of transfer case shift control technology, specifically relating to an automatic shift control system for a pure electric two-speed transfer case. Background Technology

[0002] With the rapid development of pure electric vehicles, optimizing the performance of electric drive systems has become a focus of industry attention. The powertrain of a pure electric vehicle typically consists of an electric motor and a two-speed mechanical transmission. This two-speed mechanical transmission is simple in structure, small in size, lightweight, and low in cost. By providing two different gear ratios, it can deliver greater torque output at low speeds and reduce motor speed at high speeds, thereby improving energy efficiency and driving range. For vehicles requiring off-road driving capabilities, an additional differential is needed to improve the vehicle's handling and stability.

[0003] The transfer case is an important component in a car's transmission system. It is connected to the gearbox and is mainly used to distribute power to different drive shafts.

[0004] When pure electric vehicles use transfer cases, the need for integrated vehicle control necessitates real-time acquisition of various operating parameters of the transfer case, along with automatic gear shifting control during driving to simplify driver operation. However, two-speed transfer cases, with their simple two-speed mechanical transmission and drive system, require manual operation to switch air circuits for gear shifting. During shifting, precise matching and control of motor speed, torque, and vehicle speed is not possible, easily leading to shift failure or power interruption. Therefore, gear shifting can only be performed when the vehicle is completely stationary.

[0005] While a two-speed transfer case that integrates a two-speed mechanical transmission and a differential can help optimize the layout of the transmission system and reduce transmission components, the aforementioned problems still exist during gear shifting. Similar issues also exist in the control of the differential, such as the need for manual operation to switch the air circuit to lock and unlock the differential lock, and the need for the vehicle to be completely stationary to open and close the differential lock.

[0006] Therefore, whether it is a two-speed transfer case that only uses a two-speed mechanical transmission or a two-speed transfer case that integrates a two-speed mechanical transmission and a differential, both have the problem of not meeting the requirements of integrated vehicle control. Utility Model Content

[0007] The purpose of this utility model is to provide an automatic shifting control system for a pure electric two-speed transfer case, which realizes the function of automatic shifting control during vehicle operation.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is: an automatic shifting control system for a pure electric two-speed transfer case, which is installed on the transfer case housing of the two-speed transfer case, including a shifting drive device and a main control module;

[0009] The shift drive device includes a cylinder housing, an air passage valve block, a shift solenoid valve, a pressure sensor, a cable connector, and position switches. The air passage valve block is mounted on the cylinder housing, and the air passage within the air passage valve block is connected to the piston chamber within the cylinder housing via the shift solenoid valve. The pressure sensor is also mounted on the air passage within the air passage valve block. The cylinder housing has two piston chambers, each movably housing a 1st gear shift fork piston and a 2nd gear shift fork piston. Position switches are mounted at corresponding positions on the 1st and 2nd gear shift fork pistons. The shift drive device is connected to the main control module via the cable connector.

[0010] The main control module includes a control unit, a main control module cable, an input speed sensor, and an output speed sensor. The control unit is connected to the input speed sensor and the output speed sensor respectively via the main control module cable. The input speed sensor and the output speed sensor are respectively installed at the input and output ends of the transfer case to obtain the rotational speed values ​​at the input and output ends of the transfer case, providing a basis for the control unit to determine the shifting timing.

[0011] The main control module cable is connected to the control unit via a control unit connection branch, to the vehicle's CAN bus via a vehicle CAN communication connection branch, to the shift drive device cable connector via a shift drive device connection branch, to the position switch via a gear position switch branch, and to the output speed sensor and input speed sensor via an output speed sensor connection branch and an input speed sensor connection branch, respectively; all connection branches are connected to the control unit via the control unit connection branch.

[0012] Furthermore, the main control module also includes a voltage regulator, and the main control module cable also includes a voltage regulator connection branch for connecting the voltage regulator.

[0013] Furthermore, the main control module also includes an oil temperature sensor, and the main control module cable also includes an oil temperature sensor connection branch for connecting the oil temperature sensor.

[0014] As another technical solution, the air passage of the air passage of the air passage valve block also includes a differential lock air passage, a differential lock solenoid valve is provided on the differential lock air passage air outlet on the air passage valve block, which is used to connect to the differential lock cylinder on the two-speed transfer case.

[0015] Furthermore, the main control module also includes a differential lock position switch, which is located at the differential lock position of the two-speed transfer case. The differential lock position switch is connected to the control unit via a main control module cable.

[0016] Furthermore, the main control module cable is also provided with a differential lock position switch connection branch. One end of the differential lock position switch connection branch is connected to the control unit connection branch, and the other end is connected to the differential lock position switch.

[0017] The beneficial effects of this utility model are: This utility model realizes the electronic and pneumatic automatic shifting control of the two-speed transfer case and the locking and unlocking control of the differential lock (when the transfer case integrates a differential with a differential lock). At the same time, it adopts CAN communication connection, which conforms to the vehicle communication standard, realizes the docking with the vehicle control system, and provides convenience for the integrated monitoring and control of the whole vehicle. It can be directly connected and used.

[0018] Compared to the original manual shift control method, the addition of an automatic control system enables automatic shift control while driving. At the same time, the system can monitor the operation of the transfer case in real time, send alarm information to the vehicle's instrument panel when a fault occurs, and restrict system functions in an emergency to protect the vehicle's equipment from further damage.

[0019] The control system is integrated into the two-speed transfer case, with only power, air supply and CAN communication interfaces reserved. The interface is simple and easy to connect, which can meet the needs of various pure electric vehicle control systems that require integrated control. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the external structure of the automatic gear shifting control system described in Example 1;

[0021] Figure 2 This is a schematic diagram of the external structure of the shift drive device described in Embodiment 1;

[0022] Figure 3 This is a schematic diagram of the structure of the shift fork shaft piston in the shift drive device described in Example 1;

[0023] Figure 4 This is a schematic diagram of the main control module described in Example 1;

[0024] Figure 5 This is a schematic diagram of the main control module cable structure described in Example 1;

[0025] The markings in the diagram are: 1. Shift drive device, 101. Cylinder housing, 102. Air circuit valve block, 103. Solenoid valve, 104. Air pressure sensor, 105. Cable connector, 106. Air source inlet, 107. Differential lock air circuit outlet, 108. Position switch, 109. 1st gear shift fork shaft piston, 110. 2nd gear shift fork shaft piston;

[0026] 2. Main control module, 201. Control unit, 202. Main control module cable, 203. Voltage regulator, 204. Input speed sensor, 205. Output speed sensor, 206. Differential lock position switch, 207. Oil temperature sensor;

[0027] 202-1, Control unit connection branch; 202-2, Vehicle CAN communication connection branch; 202-3, Gear shift drive device connection branch; 202-4, Gear position switch branch; 202-5, Oil temperature sensor connection branch; 202-6, Differential lock position switch connection branch; 202-7, Output speed sensor connection branch; 202-8, Input speed sensor connection branch; 202-9, Voltage regulator connection branch;

[0028] 3. Transfer case housing. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention in any way.

[0030] Example 1: Refer to Appendix Figure 1 As shown, an automatic shift control system for a pure electric two-speed transfer case is used for automatic shifting of a two-speed transfer case that integrates a two-speed mechanical transmission and a differential. The differential is equipped with a differential lock. The automatic shift control system mainly includes a shift drive device 1 and a main control module 2 installed on the transfer case housing 3.

[0031] The gear shift drive device 1 is mainly used to receive gear shift commands from the main control module 2, execute gear shifting actions, and simultaneously feed back parameters such as gear position and air source pressure to the main control module 2. The structure of the gear shift drive device 1 is as follows: Figure 2 , 3As shown, it mainly consists of a cylinder housing 101, an air passage valve block 102, a solenoid valve 103, a pressure sensor 104, a cable connector 105, an air source inlet 106, a differential lock air passage outlet 107, a position switch 108, a 1st gear shift fork shaft piston 109, and a 2nd gear shift fork shaft piston 110. The air passage valve block 102 is installed at one end of the cylinder housing 101. The air passage valve block 102 is provided with an air passage, including a shift air passage and a differential lock air passage. The solenoid valve 103 and the pressure sensor 104 are connected to the air passage. The solenoid valve 103 is divided into a shift solenoid valve and a differential lock solenoid valve. The shift solenoid valve is used to control the opening and closing of the shift air passage, and the differential lock solenoid valve is used to control the opening and closing of the differential lock air passage. The pressure sensor 104 is used to detect the air source pressure and convert it into an electrical signal. The air circuit valve block 102 is provided with an air source inlet 106 and a differential lock air circuit outlet 107. The air source inlet 106 is used to connect to an external air source, and the differential lock air circuit outlet 107 is used to supply air to the differential lock cylinder of the two-speed transfer case. The cylinder housing 101 is provided with two piston chambers, and a first-speed shift fork shaft piston 109 and a second-speed shift fork shaft piston 110 are movably mounted thereon. Each piston chamber is connected to two shift solenoid valves, which control the air intake in different directions, thereby driving the reciprocating motion of the shift fork shaft piston.

[0032] The shift drive device 1 is connected to the main control module 2 via the cable connector 105. On one hand, it receives the solenoid valve control signal from the main control module 2 and drives the corresponding solenoid valve 103 to open the corresponding air passage inside the air passage valve block 102. When the received command is for gear 1, it drives the corresponding gear 1 shift fork piston 109 to engage gear 1. When the received command is for gear 2, it drives the corresponding gear 2 shift fork piston 110 to engage gear 2. When the received command is for differential lock locking, it controls the differential lock solenoid valve to open, and a portion of the air source enters the differential lock cylinder of the transfer case through the differential lock air passage outlet 107, thereby locking the differential lock. Position switches 108 are respectively provided on the cylinder housing 101 at the positions corresponding to the first gear shift fork piston 109 and the second gear shift fork piston 110. When the first gear shift fork piston 109 and the second gear shift fork piston 110 are in different positions, the corresponding position switches 108 will feed back different status signals. Therefore, on the other hand, the shift drive device 1 is connected to the main control module 2 through the cable connector 105, and will also send the air source pressure signal detected by the aforementioned air pressure sensor 104 and the position signal detected by the position switch 108 to the control unit of the main control module 2 for shift logic judgment and status monitoring.

[0033] like Figure 4As shown, the main control module 2 mainly includes a control unit 201, a main control module cable 202, a voltage regulator 203, an input speed sensor 204, an output speed sensor 205, a differential lock position switch 206, and an oil temperature sensor 207. The control unit 201 is mainly used to receive signals sent back from various sensors in the system and control commands issued by the vehicle. Based on internal logic, it issues shift or differential lock locking control signals. To achieve this function, the control unit 201 is connected to the voltage regulator 203, the input speed sensor 204, the output speed sensor 205, the differential lock position switch 206, and the oil temperature sensor 207 via the main control module cable 202. The voltage regulator 203 converts the power supply voltage provided by the vehicle into a stable 24V voltage, providing a stable power supply to the control unit 201 and various sensors, ensuring the system can operate normally. The input speed sensor 204 and output speed sensor 205 are respectively installed at the input and output ends of the transfer case to acquire the rotational speed values ​​at the input and output ends of the transfer case and send these values ​​to the control unit 201. The control unit 201 determines the shifting timing based on the speed difference between the input and output ends. When the speed difference is within a set range, gear shifting can be performed. If the speed difference is not within the set range, the control unit 201 can actively control the motor to adjust the speed difference to reach the set range via CAN communication, ensuring that gear shifting can be completed during driving. The differential lock position switch 206 is installed at the differential lock position of the transfer case to provide feedback on whether the differential lock is in the locked or unlocked state, and feeds back the status signal to the control unit 201. The probe of the oil temperature sensor 207 is located inside the transfer case to collect the oil temperature value inside the transfer case in real time and feeds back the signal to the control unit 201 to determine whether the oil temperature inside the transfer case is too high or too low.

[0034] like Figure 5As shown, the main control module cable 202 mainly consists of a control unit connection branch 202-1, a vehicle CAN communication connection branch 202-2, a shift drive device connection branch 202-3, a gear position switch branch 202-4, an oil temperature sensor connection branch 202-5, a differential lock position switch connection branch 202-6, an output speed sensor connection branch 202-7, an input speed sensor connection branch 202-8, and a voltage regulator connection branch 202-9. The control unit connection branch 202-1 connects the cables from the other branches to the control unit 201. The vehicle CAN communication connection branch 202-2 connects to the vehicle's CAN bus, enabling the control unit 201 to receive shift or differential lock control commands from the vehicle via CAN communication, obtain the ignition opening of the motor connected to the transfer case and the vehicle speed, and achieve automatic shift pattern control based on these two parameters. Simultaneously, it can convert system status parameters and fault alarm information into CAN messages and send them to the vehicle's control system. It can also actively control the motor speed via CAN communication. The shift drive device connection branch 202-3 is used to connect to the shift drive device 1, enabling the control unit 201 to control the shifting action. The air pressure sensor 104 collects the air pressure value and converts it into an electrical signal, which is then sent to the control unit 201. The gear position switch branch 202-4 is used to connect to the position switch 108, enabling the control unit 201 to collect gear position information. The oil temperature sensor connection branch 202-5 is used to connect to the oil temperature sensor 207, enabling the control unit 201 to collect oil temperature information. The differential lock position switch connection branch 202-6 is used to connect to the differential lock position switch 206, enabling the control unit 201 to collect differential lock locking or unlocking status information. The output speed sensor connection branch 202-7 and the input speed sensor connection branch 202-8 are respectively connected to the output speed sensor 205 and the input speed sensor 204, enabling the control unit 201 to collect the transfer case input and output speed values. The voltage regulator connection branch 202-9 is used to connect to the voltage regulator 203.

[0035] The automatic control system of this invention can realize automatic gear shifting control during driving. Simultaneously, the system can monitor the operation of the transfer case in real time based on feedback signals from various sensors, preventing further damage to the vehicle's equipment in case of abnormalities. Details are as follows:

[0036] 1. Because low air pressure may prevent the piston from starting, there is a risk of not being able to engage gears and gear grinding, which could damage the gears. Therefore, when the control unit detects that the air pressure is lower than the set shift air pressure value through the pressure sensor, it will sound an alarm and prevent shifting.

[0037] 2. When the oil temperature sensor detects that the oil temperature is higher than the set value, it indicates that there may be an abnormal high temperature inside the transfer case. At this time, an alarm should be set to remind the user and shifting gears should be prohibited to prevent the high temperature from damaging the seals inside the transfer case.

[0038] 3. When the motor controller detects that the motor connected to the transfer case is faulty and cannot run, it converts the fault information into a CAN message and sends it to the vehicle's control system, prohibiting gear shifting;

[0039] 4. When a short circuit or open circuit fault is detected in the input speed sensor or output speed sensor, the automatic shifting mode is disabled, and the manual shifting mode can be used to control the shifting. In this mode, the control unit judges the voltage value of the speed sensor. If it is higher than the set value, it is judged as a short circuit; if it is lower than the set value, it is judged as an open circuit.

[0040] Example 2: The main difference between this example and Example 1 is that in this example, the transfer case uses a two-speed mechanical transmission type transfer case without an integrated differential. Therefore, the differential lock air outlet is no longer provided on the air circuit valve block in the shift drive device 1, and the differential lock solenoid valve is no longer provided in the solenoid valve. The differential lock position switch is no longer provided in the main control module, and the differential lock position switch connection branch is no longer provided in the main control module cable. The remaining structure is the same as in Example 1.

[0041] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the specific implementation of this utility model with reference to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model are within the protection scope of the pending claims.

Claims

1. An automatic shift control system of a pure electric two-gear transfer case, which is provided on a transfer case housing of a two-gear transfer case, characterized in that: The application relates to a shift driving device and a master control module. The shift driving device comprises a cylinder shell, a gas path valve block, a shift electromagnetic valve, a gas pressure sensor, a cable connector and a position switch, the gas path valve block is arranged on the cylinder shell, a gas channel in the gas path valve block is connected with a piston cavity in the cylinder shell through the shift electromagnetic valve, and the gas channel on the gas path valve block is further provided with the gas pressure sensor; the cylinder shell has two piston cavities, a 1st-gear shift fork shaft piston and a 2nd-gear shift fork shaft piston are movably arranged in the two piston cavities respectively, and the position switches corresponding to the 1st-gear shift fork shaft piston and the 2nd-gear shift fork shaft piston are arranged at positions respectively; the shift driving device is connected with the master control module through the cable connector. The master control module comprises a control unit, a master control module cable, an input speed sensor and an output speed sensor; the control unit is connected with the input speed sensor and the output speed sensor through the master control module cable; the input speed sensor and the output speed sensor are arranged at an input end and an output end of a transfer respectively, and are used for acquiring the rotating speed values of the input end and the output end of the transfer, so as to provide a basis for the control unit to judge the shift timing. In the master control module cable, the control unit connection branch is connected with the control unit, the vehicle CAN communication connection branch is connected with the CAN bus of the whole vehicle, the shift driving device connection branch is connected with the cable connector of the shift driving device, the gear position switch connection branch is connected with the position switch, and the output speed sensor connection branch and the input speed sensor connection branch are connected with the output speed sensor and the input speed sensor respectively. Each connection branch is connected to the control unit through the control unit connection branch.

2. The automatic gear shifting control system of a pure electric two-gear transfer case according to claim 1, characterized in that: The master control module further comprises a voltage stabilizer, and the master control module cable further comprises a voltage stabilizer connection branch used for connecting the voltage stabilizer.

3. The automatic gear shifting control system of a pure electric two-gear transfer case according to claim 1, characterized in that: The master control module further comprises an oil temperature sensor, and the master control module cable further comprises an oil temperature sensor connection branch used for connecting the oil temperature sensor.

4. The automatic gear shifting control system of a purely electric two-gear range divider according to claim 1, characterized in that: The gas channel of the gas path valve block further comprises a differential lock gas path, the differential lock gas path is provided with a differential lock electromagnetic valve, and the gas path valve block is provided with a differential lock gas path air outlet used for connecting a differential lock gas cylinder on a two-gear transfer.

5. The automatic gear shifting control system of a purely electric two-gear range divider according to claim 4, characterized in that: The master control module further comprises a differential lock position switch, the differential lock position switch is arranged at a differential lock position of the two-gear transfer, and the differential lock position switch is connected with the control unit through the master control module cable.

6. The automatic gear shifting control system of a purely electric two-gear range divider according to claim 5, characterized in that: The master control module cable is further provided with a differential lock position switch connection branch, one end of the differential lock position switch connection branch is connected with the control unit connection branch, and the other end is connected with the differential lock position switch.

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