A frame torsional rigidity testing device and testing method

Abstract

This invention discloses a vehicle frame torsional stiffness testing device and method, belonging to the technical field of vehicle frame torsional stiffness testing. The testing device includes support beams fixed to the front and rear suspensions of the vehicle frame, and corresponding support sleeves. Each support beam has two symmetrical grooves about its axis. A slider is slidably mounted within each groove, and a first spring is fixedly connected between the slider and the opposite side walls of the groove. A mounting sleeve is slidably mounted within the support sleeve, and a second spring is fixedly connected between the mounting sleeve and the inner wall of the support sleeve. A screw is threaded into the mounting sleeve, and a support plate is rotatably connected to the top of the screw. A connecting rod abuts against the support plate. A pressure sensor is installed between the mounting sleeve and the bottom wall of the support sleeve. A loading mechanism is fixedly mounted on the test area near the front suspension side of the vehicle frame. This invention avoids excessive output displacement of the loading mechanism, which could cause fatigue deformation at the connection point between the support beam and the vehicle frame, making the test results closer to actual vehicle conditions.

Description

Technical Field

[0001] This invention belongs to the field of vehicle frame torsional stiffness testing technology, specifically relating to a vehicle frame torsional stiffness testing device and testing method. Background Technology

[0002] Torsional stiffness is one of the essential performance characteristics that a vehicle frame structure must meet. During vehicle product development, the torsional stiffness of the frame structure must be tested to evaluate whether the developed frame structure meets the torsional stiffness performance requirements. Therefore, a frame structure torsional stiffness testing system is an indispensable piece of equipment in passenger vehicle product development. Constraint and loading devices are the main components of a frame structure torsional stiffness testing system.

[0003] Currently, the commonly used testing method involves static stiffness testing of the vehicle frame. This is achieved by fixing the front suspension to two rear suspension constraint clamps and using a loader to apply load to the front suspension, causing the frame of a typical passenger car to twist around the axis of rotation of a rotating T-beam. However, since the rear suspension is fixed, the displacement output by the loader must be limited when rotating the front suspension. If the loader's output displacement is too large, it can cause fatigue deformation at the connection point between the rear suspension and the rear suspension constraint clamps, or nonlinear deformation of the frame, affecting the accuracy of the torsional test. Furthermore, in actual operating environments, vehicles encounter steep slopes or high obstacles. When encountering a high obstacle at the front of the vehicle, the corresponding rear position will rise. Therefore, current static stiffness testing methods cannot accurately reflect the actual torsional stiffness of the entire vehicle.

[0004] Therefore, it is necessary to propose a frame torsional stiffness testing device and testing method to solve the above problems. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a frame torsional stiffness testing device and testing method to solve the problem that the existing method of fixing the rear suspension results in a low range of frame torsional stiffness testing and cannot accurately reflect the actual torsional stiffness of the whole vehicle.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a vehicle frame torsional stiffness testing device, comprising: two support beams fixedly connected to the vehicle frame and a support sleeve fixedly installed on the test site corresponding to the support beams. One of the two support beams is fixedly connected to the front suspension of the vehicle frame, and the other of the two support beams is fixedly connected to the rear suspension of the vehicle frame. Each support beam has two symmetrical grooves about the axis of the support beam on the side away from the vehicle frame. The line connecting the axes of the four grooves forms a rectangle. A slider is slidably installed in each groove. A first spring in a compressed state is fixedly connected between the slider and the opposite side walls of the groove. An installation sleeve is slidably installed in the support sleeve. A second spring is fixedly connected between the installation sleeve and the inner wall of the support sleeve. A screw is threaded into the installation sleeve. A support plate is rotatably connected to the top of the screw. The connecting rod abuts against the support plate. A pressure sensor for monitoring the pressure on the installation sleeve is installed between the installation sleeve and the bottom wall of the support sleeve. A loading mechanism for driving the support beam on the front suspension to rotate is fixedly installed on the test site near the front suspension side of the vehicle frame.

[0008] Furthermore, a displacement sensor for monitoring the displacement of the slider is installed inside the groove.

[0009] Furthermore, multiple force sensors are arranged side by side on the lower surface of the longitudinal beams on both sides of the frame, with each pair of force sensors corresponding to the other.

[0010] A test method for a vehicle frame torsional stiffness testing device includes the following steps:

[0011] S1: Use lifting equipment to lift the vehicle frame into the air, and then fix the two support beams 1 on the front suspension and rear suspension of the vehicle frame respectively;

[0012] S2: Drive the slider 3 to move through the drive mechanism so that the slider 3 is located in the middle of the slide groove 2. At this time, the displacement of the slider 3 detected by the displacement sensor is zero.

[0013] S3: Rotate screw 9 to make the support plates 10 inside the four support sleeves 6 at the same height and the pressure inside the four pressure sensors consistent;

[0014] S4: Use lifting equipment to lift the frame above the support sleeve 6, so that the four connecting rods 5 slide into the corresponding support sleeves 6 respectively, and the connecting rods 5 are supported on the support plate 10;

[0015] S5: By adjusting the center of gravity of the chassis, multiple test conditions are established. The height of the support plate 10 is adjusted by rotating the screw 9 to meet the preset conditions.

[0016] S6: Implement a loading test by driving the support beam 1 fixed on the front suspension of the frame to rotate by a preset angle through the loading mechanism 11, and calculate the torsional stiffness of the frame based on the values ​​of the four pressure sensors.

[0017] Furthermore, the multiple test conditions in step S5 include:

[0018] Condition 1: The center of gravity of the chassis is biased to the left side of the front suspension. By rotating the screw on the left front side, the height of the support plate on the left front side is made lower than the height of the other support plates.

[0019] Condition 2: The center of gravity of the chassis is biased to the right side of the front suspension. By rotating the screw on the right front side, the height of the support plate on the right front side is made lower than the height of the other support plates.

[0020] Condition 3: The center of gravity of the chassis is biased to the left side of the rear suspension. By rotating the screw on the left rear side, the height of the support plate on the left rear side is made lower than the height of the other support plates.

[0021] Condition 4: The center of gravity of the chassis is biased to the right side of the rear suspension. By rotating the screw on the right rear side, the height of the right rear support plate 10 is made lower than the height of the other support plates.

[0022] Condition 5: The center of gravity of the chassis is biased towards the front suspension side. By rotating the two screws on the front side, the two support plates on the front side are made to be at the same height and lower than the two support plates on the rear side.

[0023] Condition 6: The center of gravity of the chassis is biased towards the rear suspension side. By rotating the two screws on the rear side, the two support plates on the rear side are made to be at the same height and lower than the two support plates on the front side.

[0024] Condition 7: The center of gravity of the frame is biased to the left side of the frame. By rotating the two screws on the left side, the two support plates on the left side are made to be at the same height and lower than the two support plates on the right side.

[0025] In working condition eight, the center of gravity of the frame is biased to the right side of the frame. By rotating the two screws on the right side, the two support plates on the right side are made to be at the same height and lower than the two support plates on the left side.

[0026] Furthermore, in step S6, the frame torsional stiffness K is calculated using the following formula:

[0027]

[0028] The loading mechanism is located near the left side of the front suspension of the vehicle frame. L is the distance between the two connecting rods along the extension direction of the support beam. F1 is the pressure sensor value located on the left side of the front suspension of the vehicle frame, F2 is the pressure sensor value located on the right side of the front suspension of the vehicle frame, F3 is the pressure sensor value located on the left side of the rear suspension of the vehicle frame, F4 is the pressure sensor value located on the right side of the rear suspension of the vehicle frame, L0 is the sum of the values ​​of the two displacement sensors on the support beam of the front suspension, and L1 is the sum of the values ​​of the two displacement sensors on the support beam of the rear suspension.

[0029] The beneficial effects of this invention are as follows:

[0030] This invention uses a connecting rod that abuts against the support plate, allowing the loading mechanism to move the connecting rod when it outputs displacement. This prevents fatigue deformation at the connection point between the support beam and the vehicle frame caused by excessive output displacement of the loading mechanism. It breaks the output displacement limit of the loading mechanism, increasing the testing range. Furthermore, by rotating the screw, the center of gravity of the vehicle frame can be adjusted to suit various testing conditions, making the test results closer to the actual vehicle condition and improving the accuracy of the test.

[0031] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0032] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0033] Figure 1 This is a schematic diagram of the overall structure of the testing device according to an embodiment of the present invention;

[0034] Figure 2 This is an enlarged schematic diagram of a portion of the testing device according to an embodiment of the present invention.

[0035] The following components are marked in the attached diagram: support beam 1, slide groove 2, slider 3, first spring 4, connecting rod 5, support sleeve 6, mounting sleeve 7, second spring 8, screw 9, support plate 10, loading mechanism 11. Detailed Implementation

[0036] like Figures 1-2As shown, this invention provides a vehicle frame torsional stiffness testing device, comprising: two support beams 1 fixedly connected to the vehicle frame and a support sleeve 6 fixedly installed on a test site and connected to the support beams 1. One of the two support beams 1 is fixedly connected to the front suspension of the vehicle frame, and the other of the two support beams 1 is fixedly connected to the rear suspension of the vehicle frame. Two symmetrical grooves 2 about the axis of the support beam 1 are provided on the side away from the vehicle frame. The axis connecting the four grooves 2 forms a rectangle. A slider 3 is slidably installed in each groove 2. A first spring 4 in a compressed state is fixedly connected between the slider 3 and the opposite side walls of the groove 2. A displacement sensor for monitoring the displacement of the slider 3 is installed in each groove 2. The slider 3 is hinged to a connecting rod 5 on the side away from the support beam 1. The connecting rod 5 is slidably connected inside the support sleeve 6. An mounting sleeve 7 is slidably installed inside the support sleeve 6. A second spring 8 is fixedly connected between the mounting sleeve 7 and the bottom wall of the support sleeve 6. A screw 9 is threadedly connected inside the mounting sleeve 7. A support plate 10 is rotatably installed at the top of the screw 9. The connecting rod 5 abuts against the support plate 10. A pressure sensor for monitoring the pressure on the mounting sleeve 7 is installed between the mounting sleeve 7 and the bottom wall of the support sleeve 6. A loading mechanism 11 for driving the support beam on the front suspension to rotate is fixedly installed on the test site near the front suspension side of the vehicle frame. The loading mechanism 11 includes, but is not limited to, a cylinder or a hydraulic cylinder.

[0037] In this solution, the testing using the frame torsional stiffness testing device includes the following steps:

[0038] S1: Use lifting equipment to lift the vehicle frame into the air, and then fix the two support beams 1 on the front suspension and rear suspension of the vehicle frame respectively;

[0039] S2: Drive the slider 3 to move through the drive mechanism so that the slider 3 is located in the middle of the slide groove 2. At this time, the displacement of the slider 3 detected by the displacement sensor is zero.

[0040] S3: Rotate screw 9 to make the support plates 10 inside the four support sleeves 6 at the same height and the pressure inside the four pressure sensors consistent;

[0041] S4: Use lifting equipment to lift the frame above the support sleeve 6, so that the four connecting rods 5 slide into the corresponding support sleeves 6 respectively, and the connecting rods 5 are supported on the support plate 10;

[0042] S5: By adjusting the center of gravity of the chassis, multiple test conditions are established. The height of the support plate 10 is adjusted by rotating the screw 9 to meet the preset conditions.

[0043] Several test conditions include:

[0044] In working condition 1, the center of gravity of the frame is biased to the left side of the front suspension of the frame. By rotating the screw 9 on the left front side, the height of the support plate 10 on the left front side is lower than the height of the other support plates 10.

[0045] Condition 2: The center of gravity of the chassis is biased to the right side of the front suspension of the chassis. By rotating the screw 9 on the right front side, the height of the support plate 10 on the right front side is lower than the height of the other support plates 10.

[0046] Condition 3: The center of gravity of the frame is biased to the left side of the rear suspension. By rotating the screw 9 on the left rear side, the height of the support plate 10 on the left rear side is lower than the height of the other support plates 10.

[0047] Condition 4: The center of gravity of the frame is biased to the right side of the rear suspension. By rotating the screw 9 on the right rear side, the height of the support plate 10 on the right rear side is lower than the height of the other support plates 10.

[0048] Condition 5: The center of gravity of the chassis is biased towards the front suspension side. By rotating the two screws 9 on the front side, the two support plates 10 on the front side are made to be at the same height and lower than the two support plates 10 on the rear side.

[0049] Condition 6: The center of gravity of the frame is biased towards the rear suspension side. By rotating the two screws 9 on the rear side, the two support plates 10 on the rear side are made to be at the same height and lower than the two support plates 10 on the front side.

[0050] Condition 7: The center of gravity of the frame is biased to the left side of the frame. By rotating the two screws 9 on the left side, the two support plates 10 on the left side are made to be at the same height and lower than the two support plates 10 on the right side.

[0051] Condition 8: The center of gravity of the frame is biased to the right side of the frame. By rotating the two screws 9 on the right side, the two support plates 10 on the right side are made to be at the same height and lower than the two support plates 10 on the left side.

[0052] S6: Implement a loading test. Drive the support beam 1 fixed on the front suspension of the frame to rotate by a preset angle through the loading mechanism 11, and calculate the torsional stiffness of the frame based on the values ​​of the four pressure sensors.

[0053] The frame torsional stiffness K is calculated using the following formula:

[0054]

[0055] The loading mechanism 11 is located near the left side of the front suspension of the vehicle frame. L is the distance between the two connecting rods 5 along the extension direction of the support beam 1. F1 is the pressure sensor value located on the left side of the front suspension of the vehicle frame. F2 is the pressure sensor value located on the right side of the front suspension of the vehicle frame. F3 is the pressure sensor value located on the left side of the rear suspension of the vehicle frame. F4 is the pressure sensor value located on the right side of the rear suspension of the vehicle frame. L0 is the sum of the values ​​of the two displacement sensors on the support beam 1 on the front suspension. L1 is the sum of the values ​​of the two displacement sensors on the support beam 1 on the rear suspension.

[0056] During testing, the hinge point between the connecting rod 5 near the loading mechanism 11 and the support beam 1 on the front suspension is defined as hinge point a; the hinge point between the connecting rod 5 away from the loading mechanism 11 and the support beam 1 on the front suspension is defined as hinge point b; the hinge point between the connecting rod 5 on the rear suspension, which is in the same longitudinal direction as hinge point a, and the support beam 1 is defined as hinge point c; and the hinge point between the connecting rod 5 on the rear suspension, which is in the same longitudinal direction as hinge point b, and the support beam 1 is defined as hinge point d. When the output displacement of the loading mechanism 11 is within a preset range, the connecting rod 5 near the loading mechanism 11 on the front suspension rises, that is, hinge point a rises. The load mechanism 11 causes the support beam 1, which is fixed to the front suspension, to rotate around hinge point b, and hinge point b moves downward under the overturning pressure. When the output displacement of the loading mechanism 11 exceeds the preset range, the connecting rod on the front suspension near the loading mechanism 11 rises, that is, hinge point a rises, causing the support beam 1, which is fixed to the front suspension, to rotate around hinge point b, and hinge point b moves upward under the output action of the loading mechanism 11. The left extreme value of the preset range is zero, and the right extreme value of the preset range is the boundary value that can cause the connecting rod 5 on the support beam 1, which is fixed to the front suspension, away from the loading mechanism 11, to rise or fall.

[0057] This design uses a connecting rod 5 to abut against the support plate 10, allowing the loading mechanism 11 to move the connecting rod 5 when it outputs displacement. This prevents excessive output displacement of the loading mechanism 11 from causing fatigue deformation at the connection point between the support beam 1 and the vehicle frame. It breaks the output displacement limit of the loading mechanism 11, increasing the testing range. Furthermore, by rotating the screw 9, the center of gravity of the vehicle frame can be adjusted to suit various testing conditions, making the test results closer to the actual vehicle condition and improving the accuracy of the test.

[0058] In one embodiment of the invention, multiple force sensors are arranged side-by-side on the lower surface of the longitudinal beams on both sides of the frame, with each force sensor on one side corresponding to the other. The accuracy of the test is improved by averaging the values ​​sensed by each force sensor.

[0059] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A frame torsional rigidity testing device characterized by comprising: include: Two support beams are fixedly connected to the vehicle frame, and support sleeves corresponding to the support beams are fixedly installed on the test site. One of the two support beams is fixedly connected to the front suspension of the vehicle frame, and the other support beam is fixedly connected to the rear suspension of the vehicle frame. Each support beam has two symmetrical grooves about the axis of the support beam on the side away from the vehicle frame. The line connecting the axes of the four grooves forms a rectangle. A slider is slidably installed in each groove. A connecting rod is hinged to the slider on the side away from the support beam. The connecting rod is slidably connected in the support sleeve. A first spring in a compressed state is fixedly connected between the slider and the opposite side walls of the groove. An installation sleeve is slidably installed in the support sleeve. A second spring is fixedly connected between the installation sleeve and the inner wall of the support sleeve. A screw is threaded into the installation sleeve. A support plate is rotatably connected to the top of the screw. The connecting rod abuts against the support plate. A pressure sensor for monitoring the pressure on the installation sleeve is installed between the installation sleeve and the bottom wall of the support sleeve. A loading mechanism for driving the rotation of the support beam on the front suspension is fixedly installed on the test site near the front suspension side of the vehicle frame.

2. The frame torsional rigidity testing device according to claim 1, characterized by: The slide is equipped with a displacement sensor for monitoring the displacement of the slider.

3. The frame torsional rigidity testing apparatus according to claim 2, characterized by: Force sensors are installed side by side on the lower surface of the longitudinal beams on both sides of the frame, with each force sensor on both sides corresponding to the other.

4. The test method of the vehicle frame torsional rigidity test apparatus according to claim 3, characterized by, Includes the following steps: S1: Use lifting equipment to lift the vehicle frame into the air, and then fix the two support beams to the front suspension and rear suspension of the vehicle frame respectively; S2: The slider is driven to move by the drive mechanism so that the slider is located in the middle of the groove. At this time, the displacement sensor detects that the slider displacement is zero. S3: Rotate the screw to make the support plates inside the four support sleeves at the same height and the pressure inside the four pressure sensors consistent; S4: Use lifting equipment to lift the frame above the support sleeve, so that the four connecting rods slide into the corresponding support sleeves and are supported on the support plate; S5: Adjust the frame center of gravity to establish test conditions, and rotate the screws to adjust the height of the support plate to meet the preset conditions; S6: Implement a loading test by driving the support beam fixed to the front suspension of the frame to rotate by a preset angle through the loading mechanism, and calculate the torsional stiffness of the frame based on the values ​​of four pressure sensors.

5. The test method of the vehicle frame torsional rigidity test apparatus according to claim 4, characterized by, The test conditions in step S5 include: Condition 1: The center of gravity of the chassis is biased to the left side of the front suspension. By rotating the screw on the left front side, the height of the support plate on the left front side is made lower than the height of the other support plates. Condition 2: The center of gravity of the chassis is biased to the right side of the front suspension. By rotating the screw on the right front side, the height of the support plate on the right front side is made lower than the height of the other support plates. Condition 3: The center of gravity of the chassis is biased to the left side of the rear suspension. By rotating the screw on the left rear side, the height of the support plate on the left rear side is made lower than the height of the other support plates. Condition 4: The center of gravity of the chassis is biased to the right side of the rear suspension. By rotating the screw on the right rear side, the height of the right rear support plate 10 is made lower than the height of the other support plates. Condition 5: The center of gravity of the chassis is biased towards the front suspension side. By rotating the two screws on the front side, the two support plates on the front side are made to be at the same height and lower than the two support plates on the rear side. Condition 6: The center of gravity of the chassis is biased towards the rear suspension side. By rotating the two screws on the rear side, the two support plates on the rear side are made to be at the same height and lower than the two support plates on the front side. Condition 7: The center of gravity of the frame is biased to the left side of the frame. By rotating the two screws on the left side, the two support plates on the left side are made to be at the same height and lower than the two support plates on the right side. In working condition eight, the center of gravity of the frame is biased to the right side of the frame. By rotating the two screws on the right side, the two support plates on the right side are made to be at the same height and lower than the two support plates on the left side.

6. The test method of the vehicle frame torsional rigidity test apparatus according to claim 5, characterized by, In step S6, the frame torsional stiffness K The calculation is made by the following formula: The loading mechanism is located near the left side of the front suspension of the vehicle frame. This is the distance between the two connecting rods along the extension direction of the support beam. This is the value from the pressure sensor located on the left side of the front suspension of the vehicle frame. This is the value of the pressure sensor located on the right side of the front suspension of the vehicle frame; This is the value of the pressure sensor located on the left side of the rear suspension of the vehicle frame; This is the value of the pressure sensor located on the right side of the rear suspension of the vehicle frame; It is the sum of the values ​​from the two displacement sensors on the support beam of the front suspension; It is the sum of the values ​​from the two displacement sensors on the support beam of the rear suspension.

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