Vehicle connecting rod tensile strain testing device

Abstract

The utility model relates to a vehicle connecting rod tensile strain testing device, and belongs to the technical field of vehicle connecting rod testing, the vehicle connecting rod tensile strain testing device comprises a load end used for applying a load, a load shaft and a connecting device used for connecting the load shaft, one end of the connecting device is fixedly connected with the load end, and a crank holding pipe is fixedly installed on a workbench; the connecting device comprises a connecting handle used for being connected with the load end, an arc-shaped handle in threaded connection with the connecting handle and a detection structure arranged in the inner side of the connecting handle and the inner side of the arc-shaped handle. According to the tensile strain testing device for the connecting rod for the vehicle, the crank holding pipe is arranged, the strain gauges are connected and arranged in the arc-shaped handle, and meanwhile, the dial indicator is installed to measure four strain positions outside the arc-shaped handle in the connecting device, so that effective acquisition of data in the measurement process is facilitated; as the tensile load and the opening test data curve are accurately obtained, the accuracy of finally measured data can be improved, and the practicability of the device is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle connecting rod testing, and specifically to a vehicle connecting rod tensile strain testing device. Background Art

[0002] A vehicle connecting rod is an important component in a vehicle suspension system, used to connect the wheel and the vehicle body, and bear the tensile and compressive forces during vehicle driving. Strain testing is to apply a force or load to the vehicle connecting rod and measure its strain under the stressed state, so as to evaluate its stress performance and strength. In the tensile strain testing of vehicle connecting rods, strain gauges and other sensors are usually used to measure the strain value, and the data is recorded and analyzed by connecting to a data acquisition system.

[0003] The current tensile strain testing of vehicle connecting rods is for the rigidity test of the large head of the connecting rod. During the deformation process of the large head hole caused by the tensile load, the deformation amount of the large head hole close to the crankpin side is measured, so as to evaluate the fretting fatigue damage inside the large head and the durability of bearing sintering.

[0004] A strain measurement element composed of a sensitive grid, namely a strain gauge, is used for strain measurement. However, since the test connects the vehicle connecting rod through a fatigue test fixture, and since the connecting rod is a round rod and its stress deformation surface is on the side, there are certain difficulties in the setting of the strain gauge and the measurement of the deformation amount of the connecting rod. Currently, the evaluation data is obtained by measuring the connecting rod before and after the test, but the load application process is not easy to monitor. For this, a vehicle connecting rod tensile strain testing device is proposed to solve the above problems. Utility Model Content

[0005] Aiming at the deficiencies of the prior art, the present application provides a vehicle connecting rod tensile strain testing device, which has the advantages of accurate measurement of the deformation amount and opening load occurring during the test for the sample.

[0006] To achieve the above object, the present application provides the following technical solution: A vehicle connecting rod tensile strain testing device includes a load end for applying a load, a load shaft, and a connecting device for connecting the load shaft. One end of the connecting device is fixedly connected to the load end, and a crank holding tube is fixedly installed on the workbench.

[0007] The connecting device includes a connecting handle for connecting the load end, an arc handle threadedly connected to the connecting handle, and a detection structure built inside the connecting handle and the arc handle.

[0008] Further, the connecting handle and the arc handle are fixed around in a circle by bolts, and threaded holes are preset on both the connecting handle and the arc handle.

[0009] Further, the detection structure includes a strain gauge and a bearing for mounting the strain gauge, and the bearing is attached to the inner sides of the connecting handle and the arc handle.

[0010] Further, a chamfer groove is formed on the inner wall of the bearing, the strain gauge is embedded in the chamfer groove, and a cover plate is buckled on the inner wall of the bearing.

[0011] Further, the chamfer groove extends in an L shape to the outside of the bearing, and the extension of the chamfer groove can facilitate the external connection of the wire intercepted outside the strain gauge.

[0012] Further, a dial indicator retaining flat plate is fixedly installed on the outside of the crank retaining tube, and a dial indicator is fixedly installed on the dial indicator retaining flat plate through screws.

[0013] [[ID=I12]]Further, the load shaft is fixedly installed through an external large head support fixture, and a fixed ring nut is also installed at the end of the crank retaining tube.

[0014] Compared with the prior art, the technical solution of the present application has the following beneficial effects:

[0015] This vehicle connecting rod tensile strain test device, by setting a crank retaining tube, connecting and an arc handle with an internal strain gauge, and at the same time measuring four strain positions outside the arc handle in the connecting device by installing a dial indicator, helps to improve the effective acquisition of data during the measurement process. Due to the accurate acquisition of the tensile load and the data curve of the opening test, the accuracy of the finally measured data can be improved, and the practicability of the device can be improved. Brief Description of the Drawings

[0016] Figure 1 It is the front view of the overall structure of the first embodiment of the present application;

[0017] Figure 2 It is the side view of the overall structure of the first embodiment of the present application;

[0018] Figure 3 It is the partial structure schematic diagram of the connecting device of the present application;

[0019] Figure 4 It is the perspective structure schematic diagram of the strain gauge of the present application;

[0020] Figure 5 It is the structure schematic diagram of the second embodiment of the present application.

[0021] In the figure: 1. Load end; 2. Connecting device; 21. Connecting handle; 22. Arc handle; 23. Bearing; 24. Chamfer groove; 25. Strain gauge; 26. Wire; 27. Cover plate; 3. Crank retaining tube; 4. Workbench; 5. Large head support fixture; 6. Dial indicator retaining flat plate; 7. Fixed ring nut; 8. Load shaft. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] See also Figures 1-4 In this embodiment, a vehicle connecting rod tensile strain testing device includes a load end 1 for applying a load, a load shaft 8 and a connecting device 2 for connecting the load shaft 8, one end of the connecting device 2 is fixedly connected to the load end 1.

[0024] In this application, the load end 1 pulls the connecting device 2 to move, and the connecting device 2 drives the load shaft 8 to bear the load relative to the workbench 4, so as to complete the opening test of the connecting rod.

[0025] Embodiment 1: In this embodiment, crank holding tubes 3 are fixedly mounted on the workbench 4 , and the composite shaft 8 can be deformed by passing the composite shaft 8 through the two holding tubes 3 and then lifting the composite shaft 8 by the connecting device 2 .

[0026] It should be noted that the connecting device includes a connecting handle 21 for connecting the load end 1 and a curved handle 22 threadedly connected to the connecting handle 21. The connecting handle 21 and the curved handle 22 are fixed by bolts to form a circle. The connecting handle 21 and the curved handle 22 are both pre-set with threaded holes, which can facilitate the docking of the connecting handle 21 and the curved handle 22.

[0027] It also includes a detection structure built into the inner side of the connecting handle 21 and the arc-shaped handle 22. The detection structure includes a strain gauge 25 and a bearing 23 for mounting the strain gauge 25. The bearing 23 is attached to the inner side of the connecting handle 21 and the arc-shaped handle 22.

[0028] By integrating the bearing 23 into the connecting device 2 , on the one hand, a space for installing the strain gauge 25 can be provided, and on the other hand, the connection stability of the connecting device 2 can be improved.

[0029] Preferably, a chamfered groove 24 is provided on the inner wall of the bearing 23, and the strain gauge 25 is embedded in the chamfered groove 24;

[0030] Furthermore, the chamfered groove 24 extends in an L-shape to the outside of the bearing 23 , and the extension of the chamfered groove 24 can facilitate the external connection of the wire 26 outside the strain gauge 25 .

[0031] In this embodiment, a cover plate 27 is fastened on the inner wall of the bearing 23 , and the inner side of the bearing 23 can be covered by the cover plate 27 .

[0032] In the specific implementation process, the following data were obtained:

[0033] By installing the load shaft 8 on the bearing pasted with strain gauges, the zero-point adjustment of the strain gauges was carried out under the static state. Then, the compression change caused by fastening at this time was calculated. The small head end side of the composite shaft 8 was also installed on the testing machine. The tensile load was slowly increased in a fixed value lower than 2 kN, and the change of the joint surface of the cover plate 27 was recorded. As the tensile load increased, the compressive strain during installation would gradually decrease. The measurement was continued until the strain reached 0 or had no influence on the change of the load at a certain value. The number of measurements was 1 time. The target of the maximum load was about 2 times of the calculated input Fb at the large head part.

[0034] The load and each change value are shown in the following arrangement. The approximate line of the inclined part was obtained through the relationship between the average value of each calculated value and the load, and the intersection point of this approximate line and the parallel part was the opening load.

[0035] Result: Opening load Fo = 35.0 (kN), maximum input Fb = 21.9 (kN)

[0036] Please refer to Figure 5 , Example 2: In this example, a crank holding tube 3 is also inserted into the connecting device 2, and a dial gauge holding flat plate 6 is fixedly installed outside the crank holding tube 3. A dial gauge 9 is fixedly installed on the dial gauge holding flat plate 6 by screws.

[0037] The groove clearance between the connecting handle 21 and the arc handle 22 in the connecting device 2 was measured by the dial gauge 9, and the contact angle between the dial gauge measuring element and the connecting device 2 was measured. The measuring points included a total of four points at the left and right ends and the left and right ends at the rear side of the connecting device 2 in front of the crank holding tube 3.

[0038] Preferably, the load shaft 8 is fixedly installed through an external large head support fixture 5, and a fixed ring nut 7 is also installed at the end of the crank holding tube 3 to strengthen the tightness of the connection.

[0039] In the specific implementation process, the following data were obtained:

[0040] After installing the load shaft 8 on the testing machine, the connecting device, etc., a tensile load of about 1 kN was applied. At this point, the reading value of the strain gauge was set to 0 and the tensile load was slowly increased. The tensile load was gradually increased in a fixed value of 2 kN or less each time, and each gauge value (force received) was recorded. The maximum load was about 1.5 times of the calculated input power Fb at the large head part. The load and the force received at each calculated position are shown in the following arrangement. 3 measurements were carried out. The force received δ (μm) on the calculated input power Fb at the large head part was calculated through the approximate line of the average value of each measurement point.

[0041] Result: The maximum input force Fb = 21.9 (kN) under the force δ = 39.4 (μm).

[0042] The working principle of the above embodiment is as follows:

[0043] By placing the load shaft 8 inside the two crank holding tubes 3, connecting the two ends of the load shaft 8 to the big-end support fixture, and fastening the connecting handle 21 and the annular handle 22 of the connecting device 2 to the outside of the crank holding tube 3 by means of bolts, applying negative pressure through the load end 1, transmitting it through the connecting device 2, and completing data measurement through the dial indicator 9 located outside the crank holding tube 3 and the strain gauge 25 inside the bearing 23.

[0044] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0045] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A vehicle connecting rod tensile strain testing device, comprising a load end (1) for applying a load, a load shaft (8), and a connecting device (2) for connecting the load shaft (8), characterized in that: One end of the connecting device (2) is fixedly connected to the load end (1), and a crank holding tube (3) is fixedly installed on the workbench (4). The connecting device includes a connecting handle (21) for connecting the load end (1), an arc handle (22) threadedly connected to the connecting handle (21), and a detection structure built inside the inner sides of the connecting handle (21) and the arc handle (22).

2. The vehicle connecting rod tensile strain testing device according to claim 1, characterized in that: The connecting handle (21) and the arc handle (22) are fixedly surrounded in a circular shape by bolts, and threaded holes are preset on both the connecting handle (21) and the arc handle (22).

3. The vehicle connecting rod tensile strain testing device according to claim 1, wherein: The detection structure includes a strain gauge (25) and a bearing (23) for installing the strain gauge (25), and the bearing (23) is attached to the inner sides of the connecting handle (21) and the arc handle (22).

4. The vehicle connecting rod tensile strain testing device according to claim 3, characterized in that: A chamfer groove (24) is formed on the inner wall of the bearing (23), the strain gauge (25) is embedded into the chamfer groove (24), and a cover plate (27) is buckled on the inner wall of the bearing (23).

5. The vehicle connecting rod tensile strain testing device according to claim 4, characterized in that: The chamfer groove (24) extends in an L shape to the outside of the bearing (23), and the extension of the chamfer groove (24) can facilitate the external connection of a wire (26) outside the strain gauge (25).

6. The vehicle connecting rod tensile strain testing device according to claim 1, wherein: A dial indicator holding flat plate (6) is also fixedly installed on the outside of the crank holding tube (3), and a dial indicator (9) is fixedly installed on the dial indicator holding flat plate (6) by screws.

7. The vehicle connecting rod tensile strain testing device according to claim 6, wherein: The load shaft (8) is fixedly installed through an external large head support fixture (5), and a fixed ring nut (7) is also installed at the end of the crank holding tube (3).

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