An experimental tooling for the linear and angular stiffness of an automotive bushing

Abstract

The present invention provides a fixture for testing the linear and angular stiffness of automotive bushings. The fixture comprises an intermediate shaft and two T-shaped semicircular fixtures. The bushing to be fixed is inserted between the two T-shaped semicircular fixtures, and the intermediate shaft is inserted between the bushing to be fixed. The two T-shaped semicircular fixtures are bolted together. The fixture for testing the linear and angular stiffness of automotive bushings described in the present invention can share the intermediate fixture for angular stiffness testing with the linear stiffness test. The fixed and rotating end fixtures are universal structures, simple in structure, and easy to install, greatly improving the efficiency of bushing testing.

Description

Technical Field

[0001] The invention belongs to the field of bushing testing, and in particular relates to a linear and angular stiffness testing tool for automobile bushings. Background Art

[0002] In addition to metal components such as the frame, swingarm, shock absorbers, and connecting rods, the automotive chassis suspension system also includes numerous rubber bushings. These bushings reduce wear on connecting components, extending their service life. They also attenuate road excitation, reducing the transfer of vibration energy to the vehicle body and improving vehicle comfort. The linear and angular stiffness of bushings are their primary performance parameters. Rubber bushings can be manufactured in varying stiffness specifications through different formulations, production processes, and structural configurations. However, these stiffness parameters must be determined through testing using specialized equipment. The bushing specifications used vary from vehicle to vehicle, and even within the same vehicle, bushings with varying specifications and sizes may be installed in different locations. Therefore, stiffness testing requires the use of different fixtures to meet testing requirements. Since bushings have two types of stiffness—linear and angular—each type exhibits stiffness in multiple directions, each requiring separate measurement. Summary of the Invention

[0003] In view of this, the present invention aims to provide a vehicle bushing linear and angular stiffness test fixture that is easy to install, operate and change direction, thereby shortening the stiffness test time.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0005] The utility model relates to an intermediate tool for fixing a bushing, comprising an intermediate shaft and two T-shaped semicircular toolings. The bushing to be fixed is inserted in the middle of the two T-shaped semicircular toolings, the intermediate shaft is inserted in the middle of the bushing to be fixed, and the two T-shaped semicircular toolings are connected by bolts.

[0006] The T-shaped semicircular tooling includes a first connecting plate, a semicircular ring, and two second connecting plates. The two second threaded connecting plates are fixedly arranged at both ends of the semicircular ring, and the first connecting plate is fixedly arranged in the middle of the first semicircular ring.

[0007] The first connecting plate is provided with a first universal mounting hole;

[0008] The second connecting plate is provided with a second universal mounting hole.

[0009] A bushing linear test fixture device includes a base, a first intermediate fixture, an upper fixture, and a test device, wherein the first intermediate fixture is fixedly arranged on the base, the upper fixture is installed on the first intermediate fixture, and the base is fixed on the test device;

[0010] The testing equipment comprises a linear test base and a motion component; the motion component is fixed on the linear test base.

[0011] The motion assembly includes a sliding table and two sliding rods, and the sliding table is slidably mounted on the two sliding rods. The inner diameter of the T-shaped semicircular fixture is machined according to the specific test bushing size, and through holes are designed at different positions on it. After the two T-shaped semicircular fixtures are matched, a 2mm gap is left in the middle. Fasteners are then used to clamp the bushing, and the designed circular holes are used to meet the test requirements of the bushing's stiffness in three directions.

[0012] The outer diameter of the middle part of the intermediate shaft is the same as the inner diameter of the test bushing, and the outer diameter of the two end parts is a threaded screw with the same diameter as the inner diameter of the circular hole of the column;

[0013] The sliding platform is provided with a connecting column, the connecting column is fixedly connected to the upper tooling, and the sliding platform is provided with a first driving assembly;

[0014] The base includes a first base plate, a second base plate, and a mounting seat, wherein the second base plate is mounted above the first base plate, and the mounting seat is mounted on the second base plate; by adjusting the first base plate and the second base plate, adjustment in two horizontal directions can be achieved during use to meet the requirement that the loading direction coincides with the center of the bushing;

[0015] The first bottom plate is provided with a plurality of first oblong holes for mounting the test equipment, and the first oblong holes are arranged around the second bottom plate;

[0016] The second bottom plate is provided with a plurality of second oblong holes, and the first bottom plate is provided with third oblong holes corresponding to the second oblong holes; the second bottom plate and the first bottom plate are connected by screws.

[0017] The mounting base includes a third bottom plate and a base, the base is mounted on the third bottom plate, a first mounting hole is provided at the bottom of the base, and a second mounting hole corresponding to the first mounting hole is provided on the third bottom plate;

[0018] The third bottom plate is provided with a fourth oblong hole corresponding to the second oblong hole;

[0019] The base is a U-shaped structure, with third universal mounting holes on either side corresponding to the first universal mounting holes. The reinforced U-shaped structure provides a high resonant frequency, meeting both the static stiffness and dynamic performance requirements of the automotive bushing and the tooling's performance requirements. The size and spacing of the two threaded holes on the base are compatible with T-shaped semicircular tooling, ensuring reusability.

[0020] The upper fixture includes a crossbeam and two columns, with the columns mounted on either side of the crossbeam. The crossbeam and columns are designed as slide rails that allow them to slide relative to each other and are locked in place using fasteners after reaching a desired position. The sliding engagement between the crossbeam and columns is closed, with no structural openings or gaps, facilitating load transfer.

[0021] There are two fifth oblong holes on both sides of the crossbeam, and a mounting hole for mounting a connecting column is provided between the two fifth oblong holes. The two oblong holes on both sides of the crossbeam can adjust the relative position with the column during use. There is a through hole in the middle to facilitate connection with the test equipment.

[0022] The upper portion of the column is provided with a column hole for installing the column, and the bottom of the column is provided with a first mounting shaft hole for installing the intermediate shaft;

[0023] A through hole is provided on the top of the column, a sixth threaded hole is provided on the upper part of the column, and the sixth threaded hole is arranged at the bottom of the column hole.

[0024] A bushing yaw angle stiffness device includes a first angle test piece, a yaw fixing tool, a first rotating end tool, and a second intermediate tool, wherein the yaw fixing tool and the first rotating end tool are arranged on both sides of the second intermediate tool;

[0025] The first angle testing device includes a first device fixed end and a first device rotating end. The first yaw fixing fixture is connected to the first device fixed end, and the first rotating end fixture is connected to the first device rotating end.

[0026] The yaw fixing fixture includes a first flange and a mounting bracket. The mounting bracket is mounted on the first flange and is provided with a second mounting shaft hole that matches the intermediate shaft.

[0027] A bushing torsional angular stiffness device comprises a second angle test piece, a torsional fixing tool, a second rotating end tool, and a third intermediate tool, wherein the torsional fixing tool and the second rotating end tool are arranged on both sides of the third intermediate tool;

[0028] The second angle testing tool comprises a second device fixed end and a second device rotating end, the second device fixed end is connected to the torsion fixing tool, and the second device rotating end is connected to the second rotating end tool.

[0029] The torsion fixing fixture includes a second flange and a connecting frame, one end of the connecting frame is mounted on the second flange; the other end of the connecting frame is mounted on the intermediate shaft of the third intermediate fixture;

[0030] The end portion of the connecting frame is provided with a third mounting shaft hole that matches the intermediate shaft of the third intermediate tooling;

[0031] A reinforcing rib is provided in the middle of the connecting frame, and one end of the connecting frame close to the third mounting shaft hole is a trapezoidal structure.

[0032] The first rotating end tooling includes a first U-shaped connecting frame.

[0033] The open end of the first U-shaped connecting frame is provided with a fourth universal mounting hole corresponding to the first universal mounting hole;

[0034] The other end of the first U-shaped connecting frame is fixedly connected to the fixed end of the first device;

[0035] The second rotating end tooling includes a second U-shaped connecting frame;

[0036] The tops of both ends of the second U-shaped connecting frame are provided with fifth universal mounting holes corresponding to the second universal mounting holes;

[0037] The bottom of the second U-shaped connecting frame is fixedly connected to the fixed end of the second device;

[0038] A rotating connector is provided at the end of the first device rotating end and the second device rotating end, and the rotating connector is connected to the second driving member by bolts.

[0039] Compared with the prior art, the automotive bushing linear and angular stiffness test fixture created by the present invention has the following beneficial effects:

[0040] The base, upper fixture, fixed end fixture and rotating end fixture are universal fixtures that meet the size requirements of various types of bushings and can be reused. By changing the installation method of the T-shaped semicircular fixture and the bushing, stiffness tests in multiple directions can be achieved, which is simple and easy to operate. In the linear stiffness test, most of the fasteners connected to the entire fixture are axially in the same direction as the test load, and are subjected to tensile and compressive loads, avoiding the disadvantage that the fasteners have low shear strength and cannot withstand large loads. The oblong hole design of the base part can adjust the alignment relationship between the bushing and the loading center from two directions, and the operation is flexible. The middle fixture of the angular stiffness test can be shared with the linear stiffness. The fixed end fixture and the rotating end fixture are universal structures with simple structure and easy installation, which greatly improves the efficiency of the bushing test. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 This is a schematic diagram of the T-shaped semicircular tooling described in an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of a linear test fixture for automotive bushings according to an embodiment of the present invention;

[0044] Figure 3 Schematic diagram of the first base plate and the second base plate according to an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of a mounting base according to an embodiment of the present invention;

[0046] Figure 5A side view of the mounting base according to an embodiment of the present invention;

[0047] Figure 6 A schematic diagram of a base according to an embodiment of the present invention;

[0048] Figure 7 A schematic diagram of the base installation according to an embodiment of the present invention;

[0049] Figure 8 A schematic diagram of a bushing to be tested according to an embodiment of the present invention;

[0050] Figure 9 A schematic diagram of a beam according to an embodiment of the present invention;

[0051] Figure 10 A schematic diagram of a column according to an embodiment of the present invention;

[0052] Figure 11 This is an assembly diagram of a linear stiffness test according to an embodiment of the present invention;

[0053] Figure 12 This is a schematic diagram of the linear stiffness loading direction according to an embodiment of the present invention;

[0054] Figure 13 This is a schematic diagram of the direction switching of the linear stiffness test according to an embodiment of the present invention;

[0055] Figure 14 This is a diagram of the yaw angle stiffness test installation described in an embodiment of the present invention;

[0056] Figure 15 This is a diagram of the installation of the Z-axis rotational angular stiffness test according to an embodiment of the present invention;

[0057] Figure 16 This is a test diagram of the bushing's X-axis linear stiffness according to an embodiment of the present invention;

[0058] Figure 17 A partially enlarged view of the bushing X-axis linear stiffness test diagram according to an embodiment of the present invention;

[0059] Figure 18 This is a test diagram of the Z-direction linear stiffness of the bushing according to an embodiment of the present invention;

[0060] Figure 19 A partially enlarged view of the bushing Z-axis linear stiffness test according to an embodiment of the present invention;

[0061] Figure 20 This is a test diagram of the bushing X-axis angular stiffness according to an embodiment of the present invention;

[0062] Figure 21A partial enlarged view of the bushing X-axis angular stiffness test according to an embodiment of the present invention;

[0063] Figure 22 This is a test diagram of the bushing Z-direction angular stiffness according to an embodiment of the present invention;

[0064] Figure 23 A partial enlarged view of the bushing Z-direction angular stiffness test according to an embodiment of the present invention;

[0065] Figure 24 The X-axis static stiffness curve of the bushing described in the embodiment of the present invention is created;

[0066] Figure 25 The X-axis dynamic stiffness curve of the bushing described in the embodiment of the present invention is created;

[0067] Figure 26 The present invention creates the bushing Z-axis static stiffness curve described in the embodiment;

[0068] Figure 27 The Z-direction dynamic stiffness curve of the bushing described in the embodiment of the present invention is created;

[0069] Figure 28 The static stiffness curve of the bushing around the X-axis angle described in the embodiment of the present invention is created;

[0070] Figure 29 The present invention creates an embodiment of the bushing angular dynamic stiffness curve around the X-axis;

[0071] Figure 30 The static stiffness curve of the bushing around the Z axis as described in the embodiment of the present invention;

[0072] Figure 31 The present invention creates an embodiment of the bushing around the Z-axis angular dynamic stiffness curve;

[0073] Figure 32 A flow chart of the bushing stiffness test created by the present invention;

[0074] Figure 33 Assembly diagram of the bushing and intermediate tooling created for the present invention;

[0075] Figure 34 A schematic diagram of the bushing test direction created by the present invention;

[0076] Figure 35 This is a schematic diagram of the Z-direction linear stiffness installation created by the present invention;

[0077] Figure 36 Schematic diagram of the bushing yaw angle stiffness tooling created by the present invention;

[0078] Figure 37Schematic diagram of the bushing torsional angular stiffness tooling created by the present invention.

[0079] Description of reference numerals:

[0080] 1. Intermediate shaft; 2. Connecting frame; 3. First connecting plate; 4. Semicircular ring; 5. Second connecting plate; 6. Base; 7. First intermediate tooling; 8. Upper tooling; 9. Reinforcement rib; 10. Sliding table; 11. Sliding rod; 12. Connecting column; 13. First bottom plate; 14. Second bottom plate; 15. Mounting seat; 16. First oblong hole; 17. Second oblong hole; 18. Third bottom plate; 19. Base; 20. Second mounting hole; 21. Fourth oblong hole; 22. Crossbeam; 23 , column; 24, fifth oblong hole; 25, mounting column hole; 26, column hole; 27, first mounting shaft hole; 28, through hole; 29, sixth threaded hole; 30, third intermediate tooling; 31, first rotating end tooling; 32, first device fixed end; 33, first device rotating end; 34, first flange; 35, mounting bracket; 36, second device rotating end; 37, second rotating end tooling; 38, second flange; 39, second intermediate tooling; 40, second device fixed end. DETAILED DESCRIPTION

[0081] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0082] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0083] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0084] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0085] Specific implementation methods:

[0086] An intermediate fixture for fixing a bushing comprises an intermediate shaft 1 and two T-shaped semicircular fixtures. The bushing to be fixed is inserted between the two T-shaped semicircular fixtures, and the intermediate shaft 1 is inserted between the bushing to be fixed. The two T-shaped semicircular fixtures are bolted together. The T-shaped semicircular fixture comprises a first connecting plate 3, a semicircular ring 4, and two second connecting plates 5. The two second threaded connecting plates are fixedly mounted at both ends of the semicircular ring 4, and the first connecting plate 3 is fixedly mounted in the middle of the first semicircular ring 4. The first connecting plate 3 is provided with a first universal mounting hole, and the second connecting plate 5 is provided with a second universal mounting hole.

[0087] A bushing linear test fixture device includes a base 6, a first intermediate fixture 7, an upper fixture 8, and a test device. The first intermediate fixture 7 is fixedly arranged on the base 6, the upper fixture 8 is installed on the first intermediate fixture 7, and the base 6 is fixed on the test device; the test device includes a linear test base 6 and a motion component; the motion component is fixed on the linear test base 6.

[0088] The motion assembly includes a sliding table 10 and two sliding rods 11. The sliding table 10 is slidably arranged on the two sliding rods 11. The inner diameter of the T-shaped semicircular tooling is processed according to the specific test bushing size, and through holes 28 are designed at different positions thereon. After the two T-shaped semicircular toolings are matched, a 2mm gap is left in the middle, and then the bushing is clamped with fasteners, and the test requirements of the bushing stiffness in three directions are achieved through the designed circular holes. The outer diameter of the middle part of the intermediate shaft 1 is the same as the inner diameter of the test bushing, and the outer diameter of the two end parts is a threaded screw with the same inner diameter as the circular hole of the column 23. The sliding table 10 is provided with a connecting column 12, which is fixedly connected to the upper tooling 8. The sliding table 10 is provided with a first drive assembly.

[0089] The base 6 includes a first base plate 13, a second base plate 14, and a mounting seat 15. The second base plate 14 is mounted above the first base plate 13, and the mounting seat 15 is mounted on the second base plate 14. By adjusting the first base plate 13 and the second base plate 14, adjustment in two horizontal directions can be achieved during use to meet the requirement that the loading direction coincides with the center of the bushing.

[0090] The first base plate 13 is provided with a plurality of first oblong holes 16 for mounting the test equipment, and the first oblong holes 16 are arranged around the second base plate 14; the second base plate 14 is provided with a plurality of second oblong holes 17, and the first base plate 13 is provided with third oblong holes corresponding to the second oblong holes 17; the mounting base 15 includes a third base plate 18 and a base 19, and the base 19 is mounted on the third base plate 18. The bottom of the base 19 is provided with a first mounting hole, and the third base plate 18 is provided with a second mounting hole 20 corresponding to the first mounting hole; the third base plate 18 is provided with a fourth oblong hole 21 corresponding to the second oblong hole 17;

[0091] The base 19 is a U-shaped structure, and a third universal mounting hole corresponding to the first universal mounting hole is provided on both sides of the base 19. The base 19 is a U-shaped reinforced structure with a high resonance frequency, which not only meets the static stiffness requirements of the automobile bushing for the stiffness strength of the tooling, but also meets the dynamic stiffness requirements of the tooling for the dynamic performance of the tooling. The size and spacing of the two threaded holes above the base 19 match the T-shaped semicircular tooling and can be reused. The upper tooling 8 includes a crossbeam 22 and two columns 23, and the columns 23 are installed on both sides of the crossbeam 22; the crossbeam 22 and the columns 23 are slide rail structures that can slide relative to each other, and after reaching the specified position, fasteners are used to lock the position. The sliding fitting parts of the crossbeam 22 and the columns 23 do not have a closed fitting mode with a structural opening, and there is no gap, which is conducive to load transfer;

[0092] Two fifth oblong holes 24 are provided on either side of the crossbeam 22, with a mounting post hole 25 for mounting the connecting post 12 located between the two fifth oblong holes 24. The two oblong holes on either side of the crossbeam 22 allow for adjustment of their relative position with the upright posts 23 during use. A through hole 28 is located in the center for easy connection to test equipment. The upper portion of the upright posts 23 is provided with a post 23 hole for mounting the upright posts 23, and the bottom portion of the upright posts 23 is provided with a first mounting shaft hole 27 for mounting the intermediate shaft 1. A through hole 28 is provided at the top of the upright posts 23, and a sixth threaded hole 29 is provided at the upper portion of the upright posts 23, located at the bottom portion of the post 23 hole.

[0093] A bushing yaw angular stiffness device includes a first angle test piece, a yaw fixing fixture, a first rotating end fixture 31, and a second intermediate fixture 39. The yaw fixing fixture and the first rotating end fixture 31 are arranged on either side of the second intermediate fixture 39. The first angle test device includes a first device fixed end 32 and a first device rotating end 33. The first yaw fixing fixture is connected to the first device fixed end 32, and the first rotating end fixture 31 is connected to the first device rotating end 33. The yaw fixing fixture includes a first flange 34 and a mounting bracket 35. The mounting bracket 35 is mounted on the first flange 34 and is provided with a second mounting shaft hole that cooperates with the intermediate shaft 1.

[0094] A bushing torsional angular stiffness device includes a second angle test piece, a torsional fixing fixture, a second rotating end fixture 37, and a third intermediate fixture 30. The torsional fixing fixture and the second rotating end fixture 37 are arranged on both sides of the third intermediate fixture 30. The second angle test fixture includes a second device fixed end 40 and a second device rotating end 36. The second device fixed end 40 is connected to the torsional fixing fixture, and the second device rotating end 36 is connected to the second rotating end fixture 37. The torsional fixing fixture includes a second flange 38 and a connecting frame 2. One end of the connecting frame 2 is mounted on the second flange 38. The other end of the connecting frame 2 is mounted on the intermediate shaft 1 of the third intermediate fixture 30. The end of the connecting frame 2 is provided with a third mounting shaft hole that cooperates with the intermediate shaft 1 of the third intermediate fixture 30. A reinforcing rib 9 is provided in the middle of the connecting frame 2, and the end of the connecting frame 2 near the third mounting shaft hole is a trapezoidal structure. The first rotating end fixture 31 includes a first U-shaped connecting frame 2.

[0095] The open end of the first U-shaped connecting frame 2 is provided with a fourth universal mounting hole corresponding to the first universal mounting hole; the other end of the first U-shaped connecting frame 2 is fixedly connected to the first device fixed end 32; the second rotating end tooling 37 includes a second U-shaped connecting frame 2; the top of both ends of the second U-shaped connecting frame 2 is provided with fifth universal mounting holes corresponding to the second universal mounting holes; the bottom of the second U-shaped connecting frame 2 is fixedly connected to the second device fixed end 40;

[0096] The ends of the first device rotating end 33 and the second device rotating end 36 are provided with rotating connecting members, and the rotating connecting members are connected to the second driving member by bolts.

[0097] The base fixture has an oblong hole in the bottom plate with four vertically pointing M14 bolts evenly spaced in the center. The bottom plate is positioned above the bottom plate through the bolts. The base plate and the base are mounted using bolts. The two threaded holes in the base are spaced 160mm apart to meet the specifications of various automotive bushings and mate with the holes in the T-shaped semicircular fixture. The oblong holes in the overall base assembly are adjusted in the direction of the holes.

[0098] Take a certain bushing as an example, and make a T-shaped semicircular tooling and an intermediate shaft according to its size. The inner diameter of the bushing middle hole is 18mm, the outer diameter of the cylinder is 60mm, and the height of the cylinder is 66mm. The three coordinate axes of the cylinder are as follows: Figure 8 As shown in the figure, the linear stiffness of the bushing is the linear stiffness along the X, Y, and Z axes, with the load being force and the loading direction being the same as the coordinate axis. The angular stiffness is the rotational stiffness along the X, Y, and Z axes, with the load being torque and the loading direction being torque about the X, Y, and Z axes.

[0099] According to the above dimensions of the bushing, the main design of the T-shaped semicircular fixture has the same hole spacing as the base, both of which are 160mm. A 1mm gap is left between the lower plane of the fixture and the plane where the center of the semicircle is located, which is convenient for clamping the bushing after installation to prevent it from sliding and loosening after being subjected to force.

[0100] The middle part of the intermediate shaft has an outer diameter of 18mm because it fits with the middle hole of the bushing without any gap. The two ends fit with the holes of the universal tooling column and the outer diameter of the screw is 14mm.

[0101] The crossbeam has a through hole in the middle and oblong holes at both ends. The cross section of the crossbeam is similar to a trapezoidal structure. The middle hole is connected to the test equipment, and the oblong hole is connected to the column.

[0102] The column is a structure with a through hole and a trapezoidal hole. The trapezoidal hole can slide along the beam with no gap. There is a threaded hole on the lower surface of the trapezoidal hole. After being assembled with the beam to the specified position, it is tightened with bolts to ensure that there is no relative movement during the test.

[0103] Take the Y-axis linear stiffness test of the bushing as an example, as shown below. When testing the X-axis linear stiffness, after removing the upper and middle fixtures, simply rotate the bushing 90 degrees and tighten it, leaving the loading direction unchanged.

[0104] The Z-direction or axial linear stiffness test of the bushing requires the use of two additional mounting holes for constraint. The upper crossbeam used in the X- and Y-direction stiffness tests is removed, and the upper portion of the device is moved up and down so that the intermediate shaft is connected with the bolt holes above the device to achieve Z-direction loading.

[0105] The bushing angular stiffness test is divided into yaw angular stiffness and torsion angular stiffness. The yaw angular stiffness refers to the bushing's rotational stiffness around the X and Y axes, and the torsion angular stiffness refers to the bushing's rotational stiffness around the Z axis. The yaw angular stiffness is tested by installing the yaw fixed fixture, the intermediate fixture, and the rotating end fixture.

[0106] The yaw angular stiffness test around the X-axis and Y-axis is as follows Figure 16As shown, one end of the yaw fixture is connected to the equipment and the other end is connected to the intermediate shaft. One end of the fixed end fixture is connected to the equipment and the other end is connected to the T-shaped semicircular fixture. The bushing and the linear stiffness test bushing are installed in the same manner, with the outer ring connected to the T-shaped semicircular fixture and the inner ring connected to the intermediate shaft. During the test, the rotating end of the equipment drives the rotating end fixture and the T-shaped semicircular fixture (5) to rotate, and the fixed end of the equipment is connected to the yaw fixture. In this way, the intermediate shaft is fixed, the outer ring of the bushing rotates, and the inner ring is fixed to achieve the yaw angular stiffness test.

[0107] After the bushing completes the angular stiffness test around the X-axis, the angular stiffness around the Y-axis can be measured by rotating the bushing 90°, and the tooling involved remains unchanged.

[0108] The bushing angular stiffness test installation around the Z axis, the torsional fixed fixture, the T-shaped semicircular fixture, the intermediate shaft and the rotating end fixture are located in the middle area between the fixed end and the rotating end of the test equipment, wherein the torsional fixed fixture is tightened to the equipment flange by bolts, and the bushing is connected and tightened to the torsional fixed fixture through the intermediate shaft. During the test, the servo mechanism at the rotating end of the equipment drives the rotating end fixture to rotate at a certain speed, and the rotating end fixture drives the T-shaped semicircular fixture to rotate together, so that the bushing will have a constraint form in which the outer ring rotates and the inner ring is fixed, and the bushing angular stiffness around the Z axis is tested.

[0109] Taking a certain automobile subframe bushing as an example, based on the bushing dimensions of 60mm outer diameter, 18mm inner diameter, and 66mm width, a tooling design method according to the present invention is used to test the static and dynamic stiffness of the bushing. The static stiffness includes linear static stiffness and angular static stiffness, and the dynamic stiffness includes linear dynamic stiffness and angular dynamic stiffness.

[0110] First, design the intermediate fixture based on the bushing's dimensions. This fixture consists of a T-shaped semicircular fixture and an intermediate shaft. The two T-shaped semicircular fixtures are completely symmetrical, allowing the bushing to be sandwiched between them using bolts. This is then connected to the universal fixture. The intermediate shaft, with M14 threads at both ends, assembles the fixture and bushing.

[0111] Bushing through Figure 3 After assembly, it can be combined with universal tooling to carry out stiffness tests, which are divided into tests in two directions: X-direction (radial) and Z-direction (axial). Linear stiffness, angular stiffness and stiffness tests in various directions are not affected by the sequence. However, if the static and dynamic stiffness tests in the same direction are completed, switching to other directions for testing can save installation time and improve efficiency.

[0112] This time the bushing was tested for stiffness in two directions, such as Figure 34 As shown, linear stiffness and angular stiffness involve a total of 8 static-dynamic stiffness tests, and the test conditions are shown in Table 1.

[0113] Table 1 Bushing stiffness test load

[0114]

[0115] By designing the tooling of the bushing and completing the above 8 test items, the test data obtained are as follows: Figures 24 to 31 As shown in the figure, the static stiffness curves of the bushing in all directions are smooth and closed, and the dynamic stiffness curves are smooth and without fluctuations, which are consistent with the bushing's stiffness performance. The results show the stiffness range of the static stiffness and the dynamic stiffness curves as a function of frequency. The detailed data of the curves can be obtained from the original file. Based on this type of stiffness test, the bushing can be tested in advance, and the resulting data can provide data support and selection reference for the development and design of the entire vehicle or suspension.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A test fixture for linear and angular stiffness of automobile bushings, characterized by: After the bushing is assembled, it is matched with the intermediate tooling to carry out stiffness test, the linear stiffness test of the bushing, including linear stiffness test along the x, y, and z axes respectively; The bushing angular stiffness test is divided into the yaw angular stiffness test and the torsion angular stiffness test. The yaw angular stiffness refers to the rotational stiffness of the bushing around the X and Y axes, and the torsion angular stiffness refers to the rotational stiffness of the bushing around the Z axis. The intermediate tooling includes an intermediate shaft (1) and two T-shaped semicircular toolings; The bushing to be fixed is inserted in the middle of the two T-shaped semicircular fixtures, the intermediate shaft (1) is inserted in the middle of the bushing to be fixed, and the two T-shaped semicircular fixtures are connected by bolts; the T-shaped semicircular fixture comprises a first connecting plate (3), a semicircular ring (4), and two second connecting plates (5); the two second connecting plates (5) are fixedly arranged at both ends of the semicircular ring (4), and the first connecting plate (3) is fixedly arranged in the middle of the semicircular ring (4); the first connecting plate (3) is provided with a first universal mounting hole; the second connecting plate (5) is provided with a second universal mounting hole; A bushing linear stiffness test fixture device comprises a base (6), a first intermediate fixture (7), and an upper fixture (8), wherein the first intermediate fixture (7) is fixedly arranged on the base (6), the upper fixture (8) is mounted on the first intermediate fixture (7), and the base (6) is fixed on a test device; the test device comprises a linear test base and a motion component; the motion component is fixed on the linear test base; A bushing yaw angle stiffness device comprises a first angle test piece, a yaw fixing tool, a first rotating end tool (31), and a second intermediate tool (39), wherein the yaw fixing tool and the first rotating end tool (31) are arranged on both sides of the second intermediate tool (39); the first angle test piece comprises a first device fixed end (32) and a first device rotating end (33), the yaw fixing tool is connected to the first device fixed end (32), and the first rotating end tool (31) is connected to the first device rotating end (33); A bushing torsional angular stiffness device comprises a second angle test piece, a torsional fixing tool, a second rotating end tool (37), and a third intermediate tool (30), wherein the torsional fixing tool and the second rotating end tool (37) are arranged on both sides of the third intermediate tool (30); the second angle test piece comprises a second device fixed end (40) and a second device rotating end (36), wherein the second device fixed end (40) is connected to the torsional fixing tool, and the second device rotating end (36) is connected to the second rotating end tool (37); The first rotating end tooling (31) comprises a first U-shaped connecting frame, and an open end of the first U-shaped connecting frame is provided with a fourth universal mounting hole corresponding to the first universal mounting hole; The other end of the first U-shaped connecting frame is fixedly connected to the first device rotating end (33); The second rotating end tooling (37) includes a second U-shaped connecting frame; The tops of both ends of the second U-shaped connecting frame are provided with fifth universal mounting holes corresponding to the second universal mounting holes; The bottom of the second U-shaped connecting frame is fixedly connected to the second device rotating end (36); The ends of the first device rotating end (33) and the second device rotating end (36) are provided with rotating connecting pieces, and the rotating connecting pieces are connected to the second driving assembly by bolts.

2. The automotive bushing linear and angular stiffness test fixture according to claim 1, characterized in that: The motion assembly comprises a sliding table (10) and two sliding rods (11), wherein the sliding table (10) is slidably arranged on the two sliding rods (11); a connecting column (12) is provided on the sliding table (10), and the connecting column (12) is fixedly connected to the upper tooling (8); a first driving assembly is provided on the sliding table (10); the base (6) comprises a first bottom plate (13), a second bottom plate (14), and a mounting seat (15), wherein the second bottom plate (14) is mounted above the first bottom plate (13), and the mounting seat (15) is mounted on the second bottom plate (14); a plurality of mounting holes for mounting with the test equipment are provided on the first bottom plate (13). A first oblong hole (16) is provided around the second bottom plate (14); a plurality of second oblong holes (17) are provided on the second bottom plate (14); a third oblong hole corresponding to the second oblong hole (17) is provided on the first bottom plate (13); the second bottom plate (14) and the first bottom plate (13) are connected by screws; the mounting seat (15) includes a third bottom plate (18) and a base (19); the base (19) is mounted on the third bottom plate (18); a first mounting hole is provided at the bottom of the base (19); and a second mounting hole (20) corresponding to the first mounting hole is provided on the third bottom plate (18); The third bottom plate (18) is provided with a fourth oblong hole (21) corresponding to the second oblong hole (17); the third bottom plate (18) is connected to the second bottom plate (14) and the first bottom plate (13) via screws; The base (19) is a U-shaped structure, and third universal mounting holes corresponding to the first universal mounting holes are provided on both sides of the base (19).

3. The automotive bushing linear and angular stiffness test fixture according to claim 1, characterized in that: The upper tooling (8) comprises a crossbeam (22) and two upright posts (23), wherein the upright posts (23) are mounted on both sides of the crossbeam (22); Two fifth oblong holes (24) are provided on both sides of the crossbeam (22), and a mounting column hole (25) for mounting a connecting column (12) is provided between the two fifth oblong holes (24); The upper portion of the column (23) is provided with a column hole (26) for mounting the crossbeam (22), and the bottom of the column (23) is provided with a first mounting shaft hole (27) for mounting the intermediate shaft (1); The top of the column (23) is provided with a through hole (28), the upper part of the column (23) is provided with a sixth threaded hole (29), and the sixth threaded hole (29) is arranged at the bottom of the column hole.

4. The automotive bushing linear and angular stiffness test fixture according to claim 1, characterized in that: The yaw fixing fixture comprises a first flange (34) and a mounting frame (35). The mounting frame (35) is mounted on the first flange (34). The mounting frame (35) is provided with a second mounting shaft hole that matches the intermediate shaft (1).

5. The automotive bushing linear and angular stiffness test fixture according to claim 1, characterized in that: The torsion fixing fixture comprises a second flange (38) and a connecting frame (2), one end of the connecting frame (2) is mounted on the second flange (38); the other end of the connecting frame (2) is mounted on the intermediate shaft (1) of the third intermediate fixture (30); the end of the connecting frame (2) is provided with a third mounting shaft hole that matches the intermediate shaft (1) of the third intermediate fixture (30); a reinforcing rib (9) is provided in the middle of the connecting frame (2), and the end of the connecting frame (2) close to the third mounting shaft hole is a trapezoidal structure.

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