A method for detecting locking or unlocking time of differential lock of electric drive assembly

Abstract

This invention discloses a method for detecting the locking or unlocking time of a differential lock in an electric drive assembly. After the control unit sends a locking command to the differential lock, the electromagnetic coil in the differential lock pushes the engagement teeth and displacement transmission plate to move, causing the probe of the displacement sensor to shift. The time from issuing the locking command to the occurrence of the maximum displacement is the differential lock locking time. After the control unit sends an unlocking command to the differential lock, the electromagnetic coil in the differential lock retracts, and the wave spring in the differential lock pushes the engagement teeth and displacement transmission plate to move, causing the probe of the displacement sensor to shift. The time from issuing the unlocking command to the occurrence of the maximum displacement is the differential lock unlocking time. This invention can accurately detect the locking or unlocking time of a differential lock.

Description

Technical Field

[0001] This invention relates to a method for detecting the locking or unlocking time of an electric drive assembly differential lock on an automotive assembly line. Background Technology

[0002] Electronic differential lock (EDS), also known as electric drive system differential lock, is an extension of ABS. It automatically detects the rotational speed of the two drive wheels using sensors in the ABS system to determine if the wheels have lost traction, thus controlling acceleration and wheel slippage. During acceleration, when the electronic control unit determines that one drive wheel is slipping based on wheel speed signals, EDS automatically activates. When the wheel speeds differ due to slippage, the EDS system brakes the slipping wheel, improving the traction of the other drive wheel and enhancing the vehicle's traction. Once the vehicle's driving conditions return to normal, the electronic differential lock deactivates. Compared to ordinary vehicles, vehicles equipped with EDS can better utilize ground traction, improving vehicle handling, ensuring smooth driving without loss of power, thus benefiting starting, acceleration, and hill climbing.

[0003] Existing methods for testing the locking / unlocking time of differential locks in electric drive assemblies determine the locking / unlocking time based on changes in speed and torque signals. However, during the locking / unlocking process, the speed and torque fluctuate significantly during the engagement / disengagement of the gears. Furthermore, the switching of test equipment modes can also cause fluctuations in speed and torque, resulting in inaccurate test results and an inability to accurately measure the response time. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for detecting the locking or unlocking time of a differential lock in an electric drive assembly. This invention can accurately detect the locking or unlocking time of the differential lock.

[0005] The technical solutions to the above problems are as follows:

[0006] A method for detecting the locking or unlocking time of a differential lock in an electric drive assembly includes a left dynamometer, a right dynamometer, an electric drive assembly, a displacement sensor, a displacement transmission plate, a fixed component, a differential lock, and a control unit. The left and right dynamometers are respectively connected to the electric drive assembly. The displacement sensor consists of a body and a probe connected to the body. The body of the displacement sensor is fixed to the fixed component, which is fastened to the electric drive assembly. The probe of the displacement sensor cooperates with the displacement transmission plate, which is fixed to the engagement teeth in the differential lock.

[0007] After the control unit sends a locking command to the differential lock, the electromagnetic coil in the differential lock pushes the engagement teeth and displacement transmission plate to move, causing the probe of the displacement sensor to be displaced. The time from the issuance of the locking command to the occurrence of the maximum displacement is the locking time of the differential lock.

[0008] After the control unit sends an unlock command to the differential lock, the electromagnetic coil in the differential lock retracts, and the wave spring in the differential lock pushes the engagement teeth and displacement transmission plate to move, causing the probe of the displacement sensor to move. The time from the issuance of the unlock command to the occurrence of the maximum displacement is the differential lock unlock time.

[0009] Furthermore, the fixing component includes a fixing part, a clamping part, a first bolt, and a second bolt. The fixing part is fixed to the electric drive assembly by the first bolt. The clamping part is provided with an arc-shaped groove. After the body of the displacement sensor is engaged with the arc-shaped groove, the second bolt locks the clamping part, so that the body of the displacement sensor is clamped by the fixing component.

[0010] Furthermore, threaded holes are provided on the mating teeth, and the displacement transmission plate is fastened to the mating teeth with bolts, so that the mating teeth and the displacement transmission plate can move synchronously.

[0011] Furthermore, the speed modes of the left and right dynamometers are set, the speed difference is given, and the torque of the electric drive assembly is given. To prevent runaway, a lock command is sent first, and then the mode of the left or right dynamometer is switched to follow-up mode. To prevent torque over-limit, the time from sending the lock command to the left and right dynamometers switching follow-up command is set within 80ms.

[0012] Furthermore, during unlocking, an unlocking command is first sent, and then the dynamometer in follow-up mode is set to speed mode. The speed difference between the left and right dynamometers is controlled within a set threshold range. To prevent runaway, the time for sending the unlocking command to the left and right dynamometers to switch speed modes is controlled within 100ms.

[0013] In this invention, the displacement transmission plate is fastened to the engagement teeth with bolts, enabling the engagement teeth and the displacement transmission plate to move synchronously. After a locking command is sent, the electromagnetic coil pushes the engagement teeth and the displacement transmission plate to move, causing the displacement sensor probe to shift. The time from issuing the locking command to the occurrence of the maximum displacement is the differential lock locking time. After an unlocking command is sent, the electromagnetic coil retracts, and the wave spring pushes the engagement teeth and the displacement transmission plate to move, causing the displacement sensor probe to shift. The signal transmitted by the displacement sensor provides a more intuitive view of the time from sending the locking / unlocking command to the completion of locking / unlocking, thus measuring the precise locking / unlocking response time. Attached Figure Description

[0014] Figure 1This is an assembly diagram of the electric drive assembly, the left dynamometer, the right dynamometer, and the displacement sensor.

[0015] Figure 2 This is an installation diagram of the displacement transmission plate and the differential lock.

[0016] Figure 3 This is a cross-sectional view of the differential lock.

[0017] Figure 4 This is a three-dimensional view of the displacement transmission plate.

[0018] Figure 5 This is a three-dimensional view of the fixed component.

[0019] Labels in the attached diagram:

[0020] Left dynamometer 1, right dynamometer 2, electric drive assembly 3, displacement sensor 4, displacement transmission plate 5, annular component 5a, pin 5b, clearance step 5c, fixing component 7, fixing part 7a, clamping part 7b, first bolt 7c, second bolt 7d, arc groove 7e, electromagnetic coil 8, wave spring 9, half shaft gear 10. Detailed Implementation

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] like Figures 1 to 5 As shown, the present invention discloses a method for detecting the locking or unlocking time of a differential lock in an electric drive assembly, comprising a left dynamometer 1, a right dynamometer 2, an electric drive assembly 3, a displacement sensor 4, a displacement transmission plate 5, a fixing component 7, a differential lock, and a control unit. The left dynamometer 1 and the right dynamometer 2 are respectively connected to the electric drive assembly 3. The displacement sensor 4 consists of a body and a probe connected to the body. The body of the displacement sensor 4 is fixed to the fixing component 7, which is fastened to the electric drive assembly 3. The probe of the displacement sensor 4 cooperates with the displacement transmission plate 5, which is fixed to the engagement teeth 6 in the differential lock.

[0026] The displacement transmission plate 5 includes an annular component 5a and a pin 5b. The annular component 5a is located outside the engagement tooth 6 and cooperates with the differential lock. The differential lock has a half-shaft gear 10 inside. One end of the pin 5b is fixed to the inner sidewall of the annular component 5a. The pin 5b is provided with a clearance step 5c, which avoids some parts of the differential lock to avoid interference with these parts.

[0027] A threaded hole is provided on the engagement tooth 6 of the differential lock, and the displacement transmission plate 5 is fastened to the engagement tooth 6 with bolts so that the engagement tooth 6 and the displacement transmission plate 5 can move synchronously.

[0028] The fixing component 7 includes a fixing part 7a, a clamping part 7b, a first bolt 7c, and a second bolt 7d. The fixing part 7a is fixed to the electric drive assembly 3 by the first bolt 7c. The clamping part 7b is provided with an arc-shaped groove 7e. After the body of the displacement sensor 4 is engaged with the arc-shaped groove 7e, the second bolt 7d locks the clamping part 7b, so that the body of the displacement sensor 4 is clamped by the fixing component 7.

[0029] Before locking, the speed modes of the left dynamometer 1 and right dynamometer 2 are set, the speed difference is given, and the torque of the electric drive assembly 3 is given. To prevent runaway, a lock command is sent first, and then the mode of the left dynamometer 1 or right dynamometer 2 is switched to follow-up mode. To prevent torque over-limit, the time from sending the lock command to the switch of the follow-up command for the left dynamometer 1 and right dynamometer 2 is set within 80ms. After the control unit sends the lock command to the differential lock, the electromagnetic coil 8 in the differential lock pushes the engagement tooth 6 and the displacement transmission plate 5 to move, causing the probe of the displacement sensor 4 to be displaced. The time from the issuance of the lock command to the occurrence of the maximum displacement is the differential lock locking time.

[0030] Before unlocking, an unlock command is sent first. Then, the dynamometer in follow-up mode is set to speed mode, controlling the speed difference between the left dynamometer 1 and the right dynamometer 2 within a set threshold range, for example, a speed difference of less than 50 revolutions per minute. To prevent runaway, the time between sending the unlock command and switching the speed mode of the left dynamometer 1 and right dynamometer 2 is controlled within 100ms. After the control unit sends the unlock command to the differential lock, the electromagnetic coil 8 in the differential lock retracts, and the wave spring 9 in the differential lock pushes the engagement tooth 6 and the displacement transmission plate 5 to move, causing the probe of the displacement sensor 4 to displace. The time from issuing the unlock command to the occurrence of the maximum displacement is the differential lock unlocking time.

[0031] In operation, the differential lock is first engaged, and the speed modes of the left dynamometer 1 and right dynamometer 2 are set. A speed difference is given, and the torque of the electric drive assembly 3 is applied. To prevent runaway, a lock command is sent first, and then the mode of either the left dynamometer 1 or the right dynamometer 2 is switched to follow-up mode. To prevent torque over-limit, the time between sending the lock command and the dynamometer switching to follow-up mode is set within 80ms. Upon unlocking, an unlock command is sent first, and then the dynamometer in follow-up mode is set to speed mode, creating a small speed difference between the left and right dynamometers. To prevent runaway, the time between sending the unlock command and the dynamometer switching to speed mode is controlled within 100ms.

[0032] The examples described above are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the examples in the present invention without creative effort are within the scope of protection of the present invention.

Claims

1. A method for detecting the locking or unlocking time of a differential lock in an electric drive assembly, characterized in that, Includes a left dynamometer (1), a right dynamometer (2), an electric drive assembly (3), a displacement sensor (4), a displacement transmission plate (5), a fixed component (7), a differential lock, and a control unit. The left dynamometer (1) and the right dynamometer (2) are respectively connected to the electric drive assembly (3). The displacement sensor (4) consists of a body and a probe connected to the body. The body of the displacement sensor (4) is fixed to the fixed component (7). The fixed component (7) is fastened to the electric drive assembly (3). The probe of the displacement sensor (4) cooperates with the displacement transmission plate (5). The displacement transmission plate (5) is fixed on the engagement tooth (6) in the differential lock. After the control unit sends a locking command to the differential lock, the electromagnetic coil (8) in the differential lock pushes the engagement tooth (6) and the displacement transmission plate (5) to move, causing the probe of the displacement sensor (4) to be displaced. The time from the issuance of the locking command to the occurrence of the maximum displacement is the locking time of the differential lock. Before locking, the speed mode of the left dynamometer (1) and the right dynamometer (2) is set, the speed difference is given, and the torque of the electric drive assembly (3) is given. In order to prevent runaway, the locking command is sent first, and then the mode of the left dynamometer (1) or the right dynamometer (2) is switched to the follow-up mode. In order to prevent the torque from exceeding the limit, the time for sending the locking command to the left dynamometer (1) and the right dynamometer (2) to switch the follow-up command is set within 80ms. After the control unit sends an unlock command to the differential lock, the electromagnetic coil (8) in the differential lock retracts, and the wave spring (9) in the differential lock pushes the engagement tooth (6) and the displacement transmission plate (5) to move, causing the probe of the displacement sensor (4) to be displaced. The time from the issuance of the unlock command to the occurrence of the maximum displacement is the differential lock unlock time. When unlocking, the unlock command is sent first, and then the dynamometer in follow-up mode is set to speed mode. The speed difference between the left dynamometer (1) and the right dynamometer (2) is controlled within the set threshold range. In order to prevent runaway, the time for sending the unlock command to the left dynamometer (1) and the right dynamometer (2) to switch speed modes is controlled within 100ms.

2. The method for detecting the locking or unlocking time of a differential lock in an electric drive assembly according to claim 1, characterized in that, The fixing component (7) includes a fixing part (7a), a clamping part (7b), a first bolt (7c), and a second bolt (7d). The fixing part (7a) is fixed to the electric drive assembly (3) by the first bolt (7c). The clamping part (7b) is provided with an arc groove (7e). After the body of the displacement sensor (4) is engaged with the arc groove (7e), the second bolt (7d) locks the clamping part (7b) so that the body of the displacement sensor (4) is clamped by the fixing component (7).

3. The method for detecting the locking or unlocking time of a differential lock in an electric drive assembly according to claim 1, characterized in that, A threaded hole is provided on the connecting tooth (6), and the displacement transmission plate (5) is fastened to the connecting tooth (6) by bolts so that the connecting tooth (6) and the displacement transmission plate (5) can move synchronously.

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