Two-speed reduction gearbox shift durability test device and test method

Abstract

The present invention relates to the field of vehicle verification technology and discloses a two-speed gearbox shifting durability test device, comprising a test bench, a two-speed gearbox mounted on the test bench, a shifting system disposed on the input shaft of the two-speed gearbox, and a motor shaft of the test bench providing power to the output shaft of the two-speed gearbox, thereby driving the input shaft of the two-speed gearbox to rotate. The input shaft is provided with a speed detection device and a motor rotational inertia simulation device. The present invention also discloses a test method for the two-speed gearbox shifting durability test device. The two-speed gearbox shifting durability test device and its test method of the present invention simulate the inertia of an electric vehicle motor, reducing test complexity and cost, and avoiding failures that do not conform to actual operating conditions caused by excessive acceleration.

Description

Technical Field

[0001] The present invention relates to the technical field of whole vehicle verification, and in particular to a two-speed reduction gearbox shifting durability test device and a test method thereof. Background Art

[0002] Single-speed gearboxes are currently widely used in electric vehicles, but the design and use of two-speed gearboxes is increasing in high-end models to further enhance the power and economy of electric vehicles. Two-speed gearboxes offer a shifting function compared to single-speed gearboxes, but compared to traditional multi-speed transmissions, they often require motor speed regulation before shifting, making shifting conditions much more relaxed. As a core function of two-speed gearboxes, shifting durability testing is crucial for verifying this function.

[0003] Currently, there are many validation methods for shift durability testing of traditional multi-speed transmissions, such as QC / T 568, Bench Test Method for Automotive Mechanical Transmission Assemblies. However, there are no relevant standards for two-speed reduction gearboxes in electric vehicles.

[0004] Unlike traditional multi-speed transmissions, electric vehicle two-speed reduction gearboxes are directly connected to the motor. When conducting two-speed reduction gearbox shift endurance tests on a test bench, to save costs and improve test efficiency, the motor is often not installed. This results in a loss of the influence of motor inertia and a loss of the reduction gearbox input speed signal.

[0005] Therefore, it is necessary to develop a bench test device that is easy to implement for the two-speed gearbox shift durability test device. As for the two-speed gearbox shift durability test method, it is necessary to propose a more reasonable shift durability test method based on the actual shift characteristics of electric vehicles. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies of the above-mentioned technology and provide a two-speed reduction gearbox shifting durability test device and its test method, which simulates the inertia of electric vehicle motors, reduces the test complexity and test costs, and avoids failures caused by excessive acceleration that do not conform to actual working conditions.

[0007] To achieve the above objectives, the present invention provides a two-speed reduction gearbox shifting durability test device, comprising a test bench, a two-speed reduction gearbox mounted on the test bench, a shifting system arranged on the input shaft of the two-speed reduction gearbox, and a motor shaft of the test bench providing power to the output shaft of the two-speed reduction gearbox, thereby driving the input shaft of the two-speed reduction gearbox to rotate. The input shaft is provided with a speed detection device and a motor rotational inertia simulation device.

[0008] Preferably, the speed detection device includes a gear sleeved on the input shaft and a speed detector installed on the two-speed reduction gearbox to detect the speed of the gear. The gear is limited by the first spline on the input shaft and rotates driven by the input shaft and the first spline.

[0009] Preferably, the gear is provided with an inner hole which is interference-fitted with the first spline on the input shaft.

[0010] Preferably, the number of teeth Z of the gear gear ≤f TSS *60 / n max , where f TSS is the maximum frequency of the speed detector, n max is the maximum speed of the input shaft, in rpm.

[0011] Preferably, the tooth addendum of the gear is greater than the distance between the sensing units on the speed detector.

[0012] Preferably, the distance between the rotation speed detector and the gear satisfies the detection distance of the rotation speed detector.

[0013] Preferably, the motor rotational inertia simulation device includes an inertia disk sleeved on the input shaft, the rotational inertia value of the inertia disk is equal to the rotational inertia value of the electric vehicle motor, the inertia disk is limited by the second spline on the input shaft, and rotates driven by the input shaft and the second spline.

[0014] Preferably, it further comprises an end cover mounted on the housing of the two-speed reduction gearbox, the end cover is equipped with a bearing, and the inertia disc is mounted on the bearing.

[0015] Preferably, the end cover is further provided with a gasket for supporting the bearing.

[0016] A test method for the two-speed reduction gearbox shifting durability test device comprises the following steps:

[0017] A) Small speed difference shifting condition: Assume that the speed regulation accuracy of the electric vehicle motor during shifting is ± N max The speed of the motor shaft of the test bench is N, unit: rpm, N = Δn / (i1-i2), where Δn is the speed difference of the upshift. At this time, Δn = N max , i1 is the total speed ratio of the first gear, i2 is the total speed ratio of the second gear, and the speed of the motor shaft of the test bench is maintained at N = N max / (i1-i2), the two-speed reduction gearbox shifts from first gear to second gear and then shifts from second gear to first gear in one cycle, with C1 cycles;

[0018] B) Medium speed difference shifting condition: At this time, Δn=Δw*60 / 2π, Δw is the angular velocity difference between the input shafts of the gearbox before and after the shift, unit: rad / s, Δw=V 滑移 *1000*2 / d, d is the average friction diameter of the synchronizer cone of the two-speed reduction gearbox, unit: mm, V 滑移 is the slip line speed between the synchronizer cone surfaces of the two-speed reduction gearbox, unit: m / s, assuming that the maximum slip line speed that the synchronizer of the two-speed reduction gearbox can withstand is Vmax 滑移 , V 滑移 =αVmax 滑移 , α is the slip verification coefficient, the value range is 0.4~0.6 in the medium speed difference shift condition, and the speed of the motor shaft of the test bench is maintained at N=αVmax 滑移 *1000*2 / d*60 / 2 π / (i1-i2), the two-speed reduction gearbox shifts from first gear to second gear and then shifts from second gear to first gear in one cycle, which is repeated C2 times;

[0019] C) performing a cycle of step A) and step B) for D times;

[0020] D) After the cycle is completed, check the two-speed reduction gearbox;

[0021] The total friction work of the synchronizer of the two-speed reduction gearbox in the test needs to cover the total friction work W of the synchronizer of the two-speed reduction gearbox within the specified service life. 目标 ,Right now:

[0022] (2*E1*C1+2*E2*C2)*D≥β*W 目标

[0023] Where β is the verification coefficient, E1 is the single-cycle friction work of upshifting or downshifting under small speed difference shifting conditions, and E2 is the single-cycle friction work of upshifting or downshifting under medium speed difference shifting conditions. The single-cycle friction work E = 0.5*J*(2π*Δn / 60)^2, where J is the sum of the moments of inertia of the two-speed reduction gearbox and the motor moment of inertia simulation device, and Δn = N max The result is E1, Δn=αVmax 滑移 *1000*2 / d*60 / 2π is E2.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. Added input shaft speed detection function to solve the problem of missing input shaft speed signal when the test bench provides speed from the output end and does not carry out the shift endurance test of electric vehicle motor;

[0026] 2. The motor moment of inertia simulation device is used instead of the electric vehicle motor, eliminating the need to use the electric drive assembly (motor + reduction gearbox) for gear shift endurance testing, reducing test complexity and cost;

[0027] 3. The present invention adopts low speed difference and medium speed difference to carry out the gear shifting endurance test, which verifies the gear shifting function of the reduction gearbox under the conventional speed difference and accelerates the gear shifting endurance test, thereby reducing the test cycle and cost, eliminating the high speed difference gear shifting condition existing in the traditional gearbox, and avoiding the failure caused by excessive acceleration that does not conform to the actual working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a two-speed reduction gearbox in the two-speed reduction gearbox shifting durability test device of the present invention.

[0029] The components in the figure are numbered as follows:

[0030] Input shaft 1, gear 2, speed detector 3, inertia plate 4, end cover 5, bearing 6. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, a two-speed reduction gearbox shifting durability test device of the present invention includes a test bench, a two-speed reduction gearbox is mounted on the test bench, a shifting system is arranged on the input shaft of the two-speed reduction gearbox, and a motor shaft of the test bench provides power to the output shaft of the two-speed reduction gearbox, thereby driving the input shaft 1 of the two-speed reduction gearbox to rotate. The input shaft 1 is provided with a speed detection device and a motor rotational inertia simulation device.

[0033] Among them, the speed detection device includes a gear 2 mounted on the input shaft 1 and a speed detector 3 installed on the two-speed reduction gearbox to detect the speed of the gear 2. The gear 2 is limited by the first spline on the input shaft 1 and rotates driven by the input shaft 1 and the first spline. The gear 2 is provided with an inner hole that is interference fit with the first spline on the input shaft 1.

[0034] In this embodiment, the number of teeth of the gear is Z gear ≤f TSS *60 / n max , where f TSS is the maximum frequency of the speed detector, n max is the maximum speed of the input shaft, unit: rpm, the tooth addendum of the gear is greater than the distance between the sensing units on the speed detector, and the distance between the speed detector and the gear meets the detection distance of the speed detector.

[0035] In addition, the motor rotational inertia simulation device includes an inertia disk 4 mounted on the input shaft 1. The rotational inertia value of the inertia disk 4 is equal to the rotational inertia value of the electric vehicle motor. The inertia disk 4 is limited by the second spline on the input shaft 1 and rotates driven by the input shaft 1 and the second spline.

[0036] At the same time, an end cover 5 is installed on the housing of the two-speed reduction gearbox. The end cover 5 is equipped with a bearing 6. The bearing 6 comes with grease. The inertia disc 4 is installed on the bearing 6, that is, one end of the inertia disc 4 is installed on the bearing 6, and the other end is installed on the input shaft 1. A gasket is also provided on the end cover 5 to resist the bearing 6 to prevent axial movement of the inertia disc 4.

[0037] In this embodiment, the input shaft 1 of the two-speed reduction gearbox is provided with a first spline and a second spline. In other embodiments, if the input shaft 1 is not provided with a spline, it can be processed to provide the first spline and the second spline.

[0038] The test method of the two-speed reduction gearbox shifting durability test device of this embodiment includes the following steps:

[0039] A) Small speed difference shifting condition: Assume that the speed regulation accuracy of the electric vehicle motor during shifting is ± N max The speed of the motor shaft of the test bench is N, unit: rpm, N = Δn / (i1-i2), where Δn is the speed difference of the upshift. At this time, Δn = N max , i1 is the total speed ratio of the first gear, i2 is the total speed ratio of the second gear, and the speed of the motor shaft of the test bench is maintained at N = N max / (i1-i2), the two-speed reduction gearbox shifts from first gear to second gear and then shifts from second gear to first gear, which constitutes one cycle, and the cycle is C1 times;

[0040] B) Medium speed difference shifting condition: At this time, Δn=Δw*60 / 2π, Δw is the angular velocity difference of the reduction gearbox input shaft 1 before and after the shift, unit: rad / s, Δw=V 滑移 *1000*2 / d, d is the average friction diameter of the synchronizer cone of the two-speed reduction gearbox, unit: mm, V 滑移 is the slip line speed between the synchronizer cone surfaces of the two-speed reduction gearbox, unit: m / s, assuming that the maximum slip line speed that the synchronizer of the two-speed reduction gearbox can withstand is Vmax 滑移 , V 滑移 =αVmax 滑移 α is the slip verification coefficient, which is in the range of 0.4 to 0.6 in the medium speed difference shifting condition, and is 0.5 in this embodiment. The speed of the motor shaft of the test bench is maintained at N = αVmax 滑移 *1000*2 / d*60 / 2π / (i1-i2), a two-speed reduction gearbox shifts from first gear to second gear, and then shifts from second gear to first gear for one cycle, with C2 cycles;

[0041] C) performing a cycle of step A) and step B) D times;

[0042] D) After the cycle is completed, check the two-speed reduction gearbox;

[0043] The total friction work of the synchronizer of the two-speed reduction gearbox in the test needs to cover the total friction work W of the synchronizer of the two-speed reduction gearbox within the specified service life. 目标 ,Right now:

[0044] (2*E1*C1+2*E2*C2)*D≥β*W 目标

[0045] Where β is the verification coefficient, which is set according to the reliability requirements. E1 is the single-cycle friction work of upshifting or downshifting under the small speed difference shifting condition. E2 is the single-cycle friction work of upshifting or downshifting under the medium speed difference shifting condition. The single-cycle friction work E = 0.5*J*(2π*Δn / 60)^2, where J is the sum of the moments of inertia of the two-speed reduction gearbox and the motor moment of inertia simulation device, and Δn = N max The result is E1, Δn=αVmax 滑移 *1000*2 / d*60 / 2π is E2.

[0046] In this embodiment, the cycle parameters of the small speed difference shifting condition and the medium speed difference shifting condition are as follows:

[0047]

[0048] Then the total number of cycles is 5 times.

[0049] In this embodiment, the electric vehicle motor is speed-regulated before shifting. Due to the high precision of the motor's speed regulation, the medium and high speed differential shift conditions found in traditional multi-speed transmissions are eliminated. However, to shorten the shift durability test cycle and improve test efficiency, it is still necessary to increase the shift speed differential to accelerate the test. Therefore, the high speed differential shift condition found in traditional multi-speed transmissions is eliminated from the two-speed reduction gearbox shift durability test to avoid excessive acceleration and failure modes that do not conform to actual operating conditions.

[0050] The two-speed reduction gearbox shifting durability test device and test method of the present invention add an input shaft speed detection function, which solves the problem that the test bench provides the speed from the output end and the input shaft speed signal is missing when the electric vehicle motor is not used for the shifting durability test; a motor rotational inertia simulation device is used instead of the electric vehicle motor, and there is no need to use an electric drive assembly (motor + reduction gearbox) for the shifting durability test, which reduces the test complexity and test cost; the present invention uses low speed difference and medium speed difference to perform the shifting durability test, which verifies the shifting function of the reduction gearbox under conventional speed difference, and accelerates the shifting durability test, reducing the test cycle and cost, eliminating the high speed difference shifting condition existing in the traditional gearbox, and avoiding failure that does not conform to the actual working condition caused by excessive acceleration.

Claims

1. A two-speed gearbox shift durability test device, including a test bench, characterized by: A two-speed reduction gearbox is mounted on the test bench, a shifting system is arranged on the input shaft of the two-speed reduction gearbox, a motor shaft of the test bench provides power to the output shaft of the two-speed reduction gearbox, thereby driving the input shaft (1) of the two-speed reduction gearbox to rotate, and a speed detection device and a motor rotational inertia simulation device are arranged on the input shaft (1); The rotation speed detection device comprises a gear (2) sleeved on the input shaft (1) and a rotation speed detector (3) mounted on the two-speed reduction gearbox for detecting the rotation speed of the gear (2); the gear (2) is limited by a first spline on the input shaft (1) and rotates under the drive of the input shaft (1) and the first spline; The motor rotational inertia simulation device comprises an inertia disc (4) sleeved on the input shaft (1); the rotational inertia value of the inertia disc (4) is equal to the rotational inertia value of the electric vehicle motor; the inertia disc (4) is limited by a second spline on the input shaft (1) and rotates under the drive of the input shaft (1) and the second spline.

2. The two-speed reduction gearbox shifting durability test device according to claim 1, characterized in that: The gear (2) is provided with an inner hole which is interference-fitted with the first spline on the input shaft (1).

3. The two-speed reduction gearbox shifting durability test device according to claim 1, characterized in that: The number of teeth Z of the gear (2) gear ≤f TSS *60 / n max , where f TSS is the maximum frequency of the speed detector (3), n max is the maximum rotational speed of the input shaft (1), unit: rpm.

4. The two-speed reduction gearbox shifting durability test device according to claim 1, characterized in that: The tooth addendum of the gear (2) is greater than the distance between the sensing units on the speed detector (3).

5. The two-speed reduction gearbox shifting durability test device according to claim 1, characterized in that: The distance between the rotation speed detector (3) and the gear (2) satisfies the detection distance of the rotation speed detector (3).

6. The two-speed reduction gearbox shifting durability test device according to claim 1, characterized in that: It also includes an end cover (5) mounted on the two-speed reduction box housing, the end cover (5) is equipped with a bearing (6), and the inertia disc (4) is mounted on the bearing (6).

7. The two-speed reduction gearbox shifting durability test device according to claim 6, characterized in that: The end cover (5) is also provided with a gasket that abuts against the bearing (6).

8. A test method for the two-speed reduction gearbox shifting durability test device according to any one of claims 1 to 7, characterized in that: The steps include: A) Small speed difference shifting condition: Assume that the speed regulation accuracy of the electric vehicle motor during shifting is ±N max The speed of the motor shaft of the test bench is N, unit: rpm, N = Δn / (i1-i2), where Δn is the speed difference of the upshift. At this time, Δn = N max , i1 is the total speed ratio of the first gear, i2 is the total speed ratio of the second gear, and the speed of the motor shaft of the test bench is kept at N=N max / (i1-i2), the two-speed reduction gearbox shifts from first gear to second gear and then shifts from second gear to first gear in one cycle, with C1 cycles; B) Medium speed difference shifting condition: At this time, Δn=Δw*60 / 2π, Δw is the angular velocity difference between the two gearbox input shafts (1) before and after the shift, unit: rad / s, Δw=V 滑移 *1000*2 / d, d is the average friction diameter of the synchronizer cone of the two-speed reduction gearbox, unit: mm, V 滑移 is the slip line speed between the synchronizer cone surfaces of the two-speed reduction gearbox, unit: m / s, assuming that the maximum slip line speed that the synchronizer of the two-speed reduction gearbox can withstand is Vmax 滑移 , V 滑移 =αVmax 滑移 , α is the slip verification coefficient, the value range is 0.4~0.6 in the medium speed difference shift condition, and the speed of the motor shaft of the test bench is maintained at N=αVmax 滑移 *1000*2 / d*60 / 2π / (i1-i2), the two-speed reduction gearbox shifts from first gear to second gear and then shifts from second gear to first gear in one cycle, and the cycle is C2 times; C) performing a cycle of step A) and step B) for D times; D) After the cycle is completed, check the two-speed reduction gearbox; The total friction work of the synchronizer of the two-speed reduction gearbox in the test needs to cover the total friction work W of the synchronizer of the two-speed reduction gearbox within the specified service life. 目标 ,Right now: <h2 style=";text-align:left;direction:ltr">(2*E1*C1+2*E2*C2)*D≥β*W<h2 style=";text-align:left;direction:ltr"> 目标 Where β is the verification coefficient, E1 is the single-cycle friction work of upshifting or downshifting under small speed difference shifting conditions, and E2 is the single-cycle friction work of upshifting or downshifting under medium speed difference shifting conditions. The single-cycle friction work E = 0.5*J*(2π*Δn / 60)^2, where J is the sum of the moments of inertia of the two-speed reduction gearbox and the motor moment of inertia simulation device, and Δn = N max The result is E1, Δn=αVmax 滑移 *1000*2 / d*60 / 2π is E2.

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