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

Abstract

The invention discloses a method for detecting the locking or unlocking time of a differential lock of an electric drive assembly, which comprises the following steps: after a control unit sends a locking command to the differential lock, an electromagnetic coil in the differential lock pushes a combination tooth and a displacement conduction sheet to move, so that a probe of a displacement sensor displaces, and when the locking command is issued to the maximum displacement, the locking or unlocking time of the differential lock is detected; the time is the locking time of the differential lock; after the control unit sends an unlocking command to the differential lock, the electromagnetic coil in the differential lock retracts, the wave-shaped spring in the differential lock pushes the combination tooth and the displacement conduction piece to move, the probe of the displacement sensor is made to displace, and the time from issuing of the unlocking command to maximum displacement is the unlocking time of the differential lock. According to the invention, the locking or unlocking time of the differential lock can be accurately detected.

Description

Technical Field

[0001] The invention relates to a method for detecting locking or unlocking time of a differential lock of an electric drive assembly on an automobile assembly line. Background Art

[0002] Electronic differential lock, also known as electric drive assembly differential lock, is an extended function of ABS. The sensors of the ABS system automatically detect the rotation speed of the two driving wheels to identify whether the wheels of the car have lost the friction of the ground, so as to control the acceleration and slip of the car. During the acceleration of the car, when the electronic control unit determines that the driving wheel on one side is slipping according to the wheel speed signal, the EDS will automatically start working. When the rotation speed of the wheels on both sides is different due to wheel slip, the EDS system will brake the wheel on the slipping side, thereby improving the adhesion utilization rate of the driving wheel on the other side and improving the vehicle's passing ability. When the driving condition of the vehicle returns to normal, the electronic differential lock stops working. Compared with ordinary vehicles, vehicles with EDS can better utilize the ground adhesion to improve the vehicle's operability, ensure that the car runs smoothly without losing power, which is conducive to starting, accelerating and climbing.

[0003] The existing electric drive assembly differential lock locking / unlocking time test method determines the differential lock locking / unlocking time based on the speed and torque signal changes. However, when the differential lock is locked / unlocked, the speed and torque fluctuate greatly during the engagement / disengagement process of the coupling teeth, and the speed and torque fluctuate when the test equipment mode is switched, resulting in inaccurate test results and an inability to accurately measure the response time. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting the locking or unlocking time of a differential lock of an electric drive assembly in view of the corresponding deficiencies in the prior art. The present invention can accurately detect the locking or unlocking time of the differential lock.

[0005] The technical solutions to the above problems are as follows: A method for detecting the locking or unlocking time of a differential lock of an electric drive assembly includes a left dynamometer, a right dynamometer, an electric drive assembly, a displacement sensor, a displacement conduction sheet, a fixing component, a differential lock, and a control unit. The left dynamometer and the right dynamometer are respectively connected to the electric drive assembly. The displacement sensor is composed of a body and a probe connected to the body. The body of the displacement sensor is fixed to the fixing component, which is fastened to the electric drive assembly. The probe of the displacement sensor cooperates with the displacement conduction sheet, which is fixed to a coupling tooth in the differential lock. After the control unit sends a locking command to the differential lock, the electromagnetic coil in the differential lock pushes the coupling teeth and the displacement transmission plate to move, causing the probe of the displacement sensor to move. The time from the issuance of the locking command to the occurrence of the maximum displacement is the locking time of the differential lock; 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 coupling teeth and the displacement transmission plate to move, causing the probe of the displacement sensor to move. The time from when the unlocking command is issued to when the maximum displacement occurs is the differential lock unlocking time.

[0006] Furthermore, the fixing component includes a fixing portion, a clamping portion, a first bolt, and a second bolt. The fixing portion is fixed to the electric drive assembly by the first bolt, and an arc groove is provided on the clamping portion. After the body of the displacement sensor cooperates with the arc groove, the second bolt locks the clamping portion so that the body of the displacement sensor is clamped by the fixing component.

[0007] Furthermore, a threaded hole is provided on the coupling tooth, and the displacement conducting plate is fastened to the coupling tooth by means of bolts, so that the coupling tooth and the displacement conducting plate can move synchronously.

[0008] Furthermore, the speed modes of the left dynamometer and the right dynamometer are set, the speed difference is given, and the torque of the electric drive assembly is given. In order to prevent runaway, a locking command is first sent, and then the mode of the left dynamometer or the right dynamometer 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 and the right dynamometer to switch the follow-up command is set within 80ms.

[0009] Furthermore, when unlocking, an unlock command is sent first, and then the dynamometer in the follow-up mode is set to the speed mode, and the speed difference between the left dynamometer and the right dynamometer is controlled within the set threshold range. In order to prevent runaway, the time for sending the unlock command to the left dynamometer and the right dynamometer to switch the speed mode is controlled within 100ms.

[0010] In the present invention, the displacement conduction plate is fastened to the coupling tooth by bolts, so that the coupling tooth and the displacement conduction plate can move synchronously. After sending the locking command, the electromagnetic coil pushes the coupling tooth and the displacement conduction plate to move, causing the displacement sensor probe to be displaced. The time from sending the locking command to the maximum displacement is the differential lock locking time. After sending the unlocking command, the electromagnetic coil retracts, and the wave spring pushes the coupling tooth and the displacement conduction plate to move, causing the displacement sensor probe to be displaced. Through the signal transmitted by the displacement sensor, the time from sending the locking / unlocking command to the completion of locking / unlocking can be more intuitively seen, thereby measuring the accurate locking / unlocking response time. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the assembly drawing of the electric drive assembly, the left dynamometer, the right dynamometer, and the displacement sensor.

[0012] Figure 2 This is the installation diagram of the displacement transmission plate and the differential lock.

[0013] Figure 3 A cross-sectional view of a differential lock.

[0014] Figure 4 It is a three-dimensional diagram of the displacement conduction sheet.

[0015] Figure 5 A three-dimensional diagram of the fixed components.

[0016] Markings in the attached drawings: Left dynamometer 1, right dynamometer 2, electric drive assembly 3, displacement sensor 4, displacement conduction sheet 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 DESCRIPTION

[0017] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential” and the like to indicate orientations or positional relationships, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0018] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0019] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] like Figures 1 to 5 As shown, a method for detecting locking or unlocking time of a differential lock of an electric drive assembly of the present invention comprises a left dynamometer 1, a right dynamometer 2, an electric drive assembly 3, a displacement sensor 4, a displacement conduction sheet 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 is composed of a body and a probe connected to the body. The body of the displacement sensor 4 is fixed to the fixing component 7, and the fixing component 7 is fastened to the electric drive assembly 3. The probe of the displacement sensor 4 cooperates with the displacement conduction sheet 5, and the displacement conduction sheet 5 is fixed to the coupling tooth 6 in the differential lock.

[0022] The displacement transmission plate 5 includes an annular component 5a and a pin 5b. The annular component 5a is located on the outside of the coupling tooth 6. The annular component 5a cooperates with the differential lock. The differential lock has a half-shaft gear 10. One end of the pin 5b is fixed to the inner wall of the annular component 5a. The pin 5b is provided with a clearance step 5c. The clearance step 5c avoids some parts of the differential lock to avoid interference with these parts.

[0023] A threaded hole is provided on the coupling tooth 6 of the differential lock, and the displacement transmission piece 5 is fastened to the coupling tooth 6 by bolts, so that the coupling tooth 6 and the displacement transmission piece 5 can move synchronously.

[0024] The fixing component 7 includes a fixing portion 7a, a clamping portion 7b, a first bolt 7c, and a second bolt 7d. The fixing portion 7a is fixed to the electric drive assembly 3 by the first bolt 7c. The clamping portion 7b is provided with an arc groove 7e. After the body of the displacement sensor 4 is matched with the arc groove 7e, the second bolt 7d locks the clamping portion 7b, so that the body of the displacement sensor 4 is clamped by the fixing component 7.

[0025] Before locking, set the speed mode of the left dynamometer 1 and the right dynamometer 2, give the speed difference, and give the torque of the electric drive assembly 3. In order to prevent the vehicle from flying, first send a locking command, and then switch the mode of the left dynamometer 1 or the right dynamometer 2 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 the locking command to the differential lock, the electromagnetic coil 8 in the differential lock pushes the coupling tooth 6 and the displacement transmission sheet 5 to move, so that the probe of the displacement sensor 4 is 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.

[0026] Before unlocking, send an unlock command first, then set the dynamometer in follow-up mode to the speed mode, and control the speed difference between the left dynamometer 1 and the right dynamometer 2 within the set threshold range, for example, the speed difference is less than 50 revolutions per minute. In order to prevent runaway, send the unlock command to the left dynamometer 1 and the right dynamometer 2 to switch the speed mode 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 coupling tooth 6 and the displacement transmission sheet 5 to move, causing the probe of the displacement sensor 4 to shift. The time from issuing the unlock command to the maximum displacement is the differential lock unlocking time.

[0027] When the present invention is working, the differential lock is first locked, the speed mode of the left dynamometer 1 and the right dynamometer 2 is set, the speed difference is given, the torque of the electric drive assembly 3 is given, and in order to prevent the vehicle from flying, a locking command is first sent, 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 dynamometer to switch the follow-up command is set within 80ms. When unlocking, the unlocking command is first sent, and then the dynamometer in the follow-up mode is set to the speed mode, so that the left and right dynamometers have a small speed difference. In order to prevent the vehicle from flying, the time for sending the unlocking command to the dynamometer to switch the speed mode is controlled within 100ms.

[0028] The examples described above are only some embodiments of the present invention, rather than all of them. Based on the examples in the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work 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 of an electric drive assembly, characterized in that: The invention comprises a left dynamometer (1), a right dynamometer (2), an electric drive assembly (3), a displacement sensor (4), a displacement transmission sheet (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) comprises a body and a probe connected to the body. The body of the displacement sensor (4) is fixed to the fixing component (7). The fixing component (7) is fastened to the electric drive assembly (3). The probe of the displacement sensor (4) cooperates with the displacement transmission sheet (5). The displacement transmission sheet (5) is fixed to a coupling 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 coupling tooth (6) and the displacement transmission plate (5) to move, causing the probe of the displacement sensor (4) to move. The time from when the locking command is sent to when the maximum displacement occurs is the locking time of the differential lock. 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 coupling tooth (6) and the displacement transmission plate (5) to move, causing the probe of the displacement sensor (4) to move. The time from the issuance of the unlock command to the occurrence of the maximum displacement is the differential lock unlock time.

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

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

4. The method for detecting locking or unlocking time of a differential lock of an electric drive assembly according to claim 1, characterized in that: The speed modes of the left dynamometer (1) and the right dynamometer (2) are set, the speed difference is given, and the torque of the electric drive assembly (3) is given. In order to prevent the vehicle from running away, a locking command is first sent, and then the mode of the left dynamometer (1) or the right dynamometer (2) is switched to a 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) and switching the follow-up command is set within 80ms.

5. The method for detecting locking or unlocking time of a differential lock of an electric drive assembly according to claim 1, characterized in that: When unlocking, an unlock command is first sent, and then the dynamometer in the follow-up mode is set to the speed mode, and 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 the speed mode is controlled within 100ms.

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