A torsion testing device and a testing method thereof

Abstract

The present application relates to the technical field of torsion test, in particular to a torsion test device and a test method thereof, the torsion test device comprises a base, two mounting seats are arranged on the base, a clamping mechanism is arranged on each mounting seat, the clamping mechanism comprises a first sleeve, a second sleeve is threadedly sleeved on the first sleeve, a clamping sleeve is inserted and arranged in the second sleeve, the clamping sleeve can move with the second sleeve and can expand and contract in the circumferential direction, and the clamping sleeve is used for clamping shaft workpieces; a guide sleeve is inserted and arranged between the clamping sleeve and the second sleeve, the guide sleeve and the clamping sleeve form a guide fit, so that the clamping sleeve can contract and clamp the shaft workpieces; one of the first sleeves can rotate around its own axis, and the rotating direction is opposite to the tightening direction of the second sleeve. Therefore, when the shaft workpieces are clamped, the appropriate clamping force is ensured, and when the torsion test is carried out, the clamping force can continuously increase with the torsional moment borne by the shaft workpieces, so that the clamping stability is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of torsion testing, in particular to a torsion testing device and a testing method thereof. BACKGROUND

[0002] As a core component in mechanical transmission systems, the torsional performance of shaft workpieces is directly related to the running stability and safety of the entire equipment. Therefore, after processing, accurate torsion testing is a key link to ensure product quality standards. This testing process can effectively detect the mechanical response of shaft workpieces when subjected to torsional moments, including maximum torsional moment, torsional angle, yield point and other key parameters, providing a scientific basis for determining whether the shaft workpiece meets the use requirements.

[0003] When testing the torsion of shaft workpieces, a torsion testing machine is needed. In related technologies, such as Chinese patent CN117168796B, a torsion testing device of a rotating shaft structure is disclosed. When in use, the device clamps the two ends of the shaft workpiece with a fixed clamping assembly and a movable clamping assembly, respectively, then keeps the fixed clamping assembly stationary, and rotates the end of the shaft workpiece driven by the movable clamping assembly to achieve torsion testing of the shaft workpiece.

[0004] However, the existing torsion testing machine also has some problems when testing the torsion of shaft workpieces: the clamping force on the shaft workpiece is usually a fixed value, which can lead to two extreme situations during testing: on the one hand, if the initial clamping force is too large, it may cause damage to the surface of the workpiece during the clamping stage, or even cause micro-deformation of the internal structure. This damage will directly affect the accuracy of the test results, making the torsion parameters obtained by testing unable to truly reflect the actual performance of the workpiece; on the other hand, if the initial clamping force is too small, during the gradual increase of the torsional moment of the workpiece during testing, relative sliding may occur between the workpiece and the clamping assembly, i.e. the workpiece may slip off, which not only causes the test to be interrupted, affecting the normal progress of the test, but also may cause secondary damage to the equipment or workpiece due to the impact force during the slipping moment. SUMMARY

[0005] Therefore, it is necessary to provide a torsion testing device and a testing method thereof to solve the problems of low accuracy of test results and poor continuity of testing during the torsion testing process of shaft workpieces.

[0006] The above-mentioned purpose is achieved by the following technical solutions:

[0007] The utility model provides a torsion testing device, which comprises a base, two mounting seats are oppositely arranged on the base, the distance between the two mounting seats can be adjusted, a clamping mechanism is arranged on each mounting seat, the clamping mechanism comprises a first sleeve, a second sleeve is threadedly sleeved on the first sleeve, a clamping sleeve is inserted into the second sleeve, the clamping sleeve can move synchronously along the axial direction of the second sleeve, can rotate synchronously with the second sleeve, and can expand and contract in the circumferential direction, and the clamping sleeve is configured to clamp a shaft workpiece, a guide sleeve is inserted between the clamping sleeve and the second sleeve, the guide sleeve and the clamping sleeve form a guide fit, so that the clamping sleeve can contract and clamp the shaft workpiece, and one of the first sleeves can rotate around its own axis in the opposite direction of the tightening direction of the second sleeve.

[0008] Further, the number of guide sleeves inserted between the clamping sleeve and the second sleeve is two, the two guide sleeves are oppositely arranged and can form a guide fit with the clamping sleeve, and the two first sleeves can rotate around their own axes in opposite directions.

[0009] Further, the guide sleeve can slide in the axial direction, a connecting seat is hingedly connected to each guide sleeve, intermediate seats are hingedly connected between the two connecting seats in the same first sleeve, an adjusting rod is arranged on the intermediate seat, the adjusting rod can rotate around its own axis, penetrates the first sleeve in the radial direction, and forms a threaded fit with the first sleeve, an adjusting ring is sleeved on each first sleeve, a first sliding groove is arranged on each adjusting ring, a sliding block is slidably inserted into the first sliding groove, and the sliding block can form a stop fit with the first sleeve and a guide fit with the adjusting rod.

[0010] Further, the number of connecting seats in the same first sleeve is multiple, the number of intermediate seats and adjusting rods is equal and twice the number of connecting seats, and they are arranged in the circumferential direction, the number of first sliding grooves arranged on each adjusting ring is multiple and arranged in the circumferential direction, and the sliding block is slidably inserted into each first sliding groove.

[0011] Further, the intermediate seat and the first sleeve are connected by an elastic member, and the intermediate seat has a tendency to move outward under the action of the elastic member.

[0012] Further, a support frame is arranged on the base, and the support frame is configured to support the shaft workpiece.

[0013] Further, the height of the support surface of the support frame can be adjusted.

[0014] Further, the support frame can slide along the axial direction of the shaft workpiece.

[0015] Further, the support frame can slide along the axial direction of the shaft workpiece.

[0016] The application also provides a torsion test method, which adopts a torsion test device, and comprises the following steps:

[0017] S1, adjusting the distance between the two mounting seats to have a preset distance;

[0018] S2, inserting one end of the shaft workpiece into the first clamping sleeve, and then tightening the second sleeve corresponding to the first clamping sleeve;

[0019] S3, adjusting the distance between the two mounting seats so that the other end of the shaft workpiece is inserted into the second clamping sleeve, and then tightening the second sleeve corresponding to the second clamping sleeve;

[0020] S4, rotating one of the first sleeves to test the torsion of the shaft workpiece.

[0021] The application has the following advantages:

[0022] The application relates to a torsion test device and a test method thereof, which is characterized in that a clamping sleeve is arranged, a guide sleeve matched with the clamping sleeve is arranged, and the motion characteristics of the rotating direction of the first sleeve and the tightening direction of the second sleeve are opposite, so that when the shaft workpiece is clamped, appropriate clamping force is ensured, the internal structure of the shaft workpiece is prevented from being damaged due to excessive clamping force, and the accuracy of the torsion test result is ensured; when the torsion test is performed, the clamping force can continuously increase with the torsional moment borne by the shaft workpiece, so that the clamping stability and the smooth test are ensured.

[0023] Further, the number of the guide sleeves arranged between the clamping sleeve and the second sleeve is two, and the motion characteristics of the two first sleeves are that they can rotate around the axis, so that the torsion fatigue test of the shaft workpiece can be performed, the function of the torsion test device can be expanded, and the applicability is improved.

[0024] Further, the adjusting rod is arranged, the sliding block matched with the adjusting rod is arranged, and the motion characteristics of the guide sleeve are that the guide sleeve can slide along the axial direction, so that when the torsion fatigue test of the shaft workpiece is performed, the clamping force compensation amount can be adjusted according to the maximum torsional moment borne by the shaft workpiece, and the clamping stability is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The torsion test device provided by the embodiment of the application is used for the torsion test of the shaft workpiece, and the three-dimensional structure schematic view is shown in the figure.

[0026] Figure 2 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0027] Figure 3 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece; Figure 2 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0028] Figure 4 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece; Figure 3 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0029] Figure 5 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0030] Figure 6 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece; Figure 5 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0031] Figure 7 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0032] Figure 8 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0033] Figure 9 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0034] Figure 10 A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0035] A side view structural schematic diagram of the torsion testing device provided by the embodiment of the present application when testing the torsion of the shaft workpiece;

[0036] 1, base; 101, second sliding groove;

[0037] 2, mounting seat; 201, mounting ring; 202, collar;

[0038] 3, clamping mechanism; 301, first sleeve; 3011, second ring table; 3012, guide bar; 3013, wing plate; 302, second sleeve; 3021, first ring table; 30211, insertion slot; 303, clamping sleeve; 3031, deformation hole; 3032, insertion convex; 3033, guide convex; 3034, friction convex; 304, guide sleeve; 3041, third sliding groove; 3042, notch; 305, connecting seat; 306, intermediate seat; 307, adjusting rod; 3071, inclined surface; 308, tension spring;

[0039] 4, adjusting ring; 401, first sliding groove;

[0040] 5. slider;

[0041] 6. support frame; 601. bottom plate; 602. vertical rod; 603. support plate;

[0042] 7. driving motor;

[0043] 8. shaft workpiece. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0045] In this document, the ordinal numbers for components, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequential or technical meaning. In this document, "connection" and "coupling" include direct and indirect connections (couplings) unless otherwise specified. In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0046] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0047] The embodiments of the present application will be described below with reference to Figures 1 to 10 The torsion testing device provided by the embodiments of the present application is particularly suitable for torsion testing of shaft workpieces 8, and of course, it is also suitable for torsion testing of other workpieces, such as shaft couplings, etc.

[0048] Specifically, the torsion testing device is provided with a base 1, a plurality of second sliding grooves 101 are formed in the top of the base 1 and extend horizontally along the front-rear direction, and the plurality of second sliding grooves 101 are arranged side by side and at intervals along the left-right direction; two mounting seats 2 are arranged on the top of the base 1 and are arranged side by side and at intervals along the front-rear direction, the two mounting seats 2 are oppositely arranged and are simultaneously and slidingly installed in the plurality of second sliding grooves 101, so that the distance between the two mounting seats 2 can be adjusted, different lengths of shaft workpieces 8 can be placed between the two mounting seats 2, the mounting seat 2 is a shell structure and is open on the side wall of the mounting seat 2 facing the middle part of the base 1, so as to facilitate receiving the shaft end of the shaft workpiece 8; a clamping mechanism 3 is installed in each mounting seat 2, and the clamping mechanism 3 is used for clamping the shaft workpiece 8. Optionally, the number of the second sliding grooves 101 can be four, and the second sliding grooves 101 are arranged at equal intervals along the left-right direction, the cross-sectional shape of the second sliding grooves 101 can be arranged as a structure with a small opening upward, such as a trapezoidal shape, so that the sliding direction of the mounting seat 2 can be guided, and the freedom degree of the mounting seat 2 sliding along the vertical direction can be limited by the self-narrowing structure, so as to ensure the clamping stability of the clamping mechanism 3.

[0049] During use, first, a suitable distance between the two mounting seats 2 is adjusted, the suitable distance is greater than the axial length of the shaft workpiece 8, so that the shaft workpiece 8 can be placed between the two mounting seats 2; specifically, one of the mounting seats 2 can be kept stationary, and the other mounting seat 2 can be driven to slide along the second sliding groove 101, so as to change the distance between the two mounting seats 2, or the two mounting seats 2 can be driven to slide along the second sliding groove 101 respectively, so as to change the distance between the two mounting seats 2.

[0050] Then, the left end of the shaft workpiece 8 is inserted into the mounting seat 2 on the left side and is clamped by the clamping mechanism 3 on the left side; then, the distance between the two mounting seats 2 is adjusted, so that the right end of the shaft workpiece 8 is inserted into the mounting seat 2 on the right side and is clamped by the clamping mechanism 3 on the right side; then, the clamping mechanism 3 on the right side is kept stationary, and the left end of the shaft workpiece 8 is driven to rotate by the clamping mechanism 3 on the left side, so as to test the torsion of the shaft workpiece 8.

[0051] It can be understood that, when the distance between the two mounting seats 2 is adjusted, the mounting seat 2 can be driven to slide along the second sliding groove 101 by a manual mode, or the mounting seat 2 can be driven to slide along the second sliding groove 101 by a mode of arranging a driving cylinder or a lead screw on the base 1; specifically, taking the driving cylinder as an example, the driving cylinder is arranged on the top of the base 1 during installation, the output shaft of the driving cylinder faces the middle part of the base 1 and is fixed on the mounting seat 2, so as to drive the mounting seat 2 to slide along the second sliding groove 101.

[0052] It can be understood that the driving cylinder can be any one of a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0053] However, the core limitation of existing torque testers lies in the fixed nature of the clamping force of the clamping mechanism 3 on the shaft workpiece 8, which is essentially contradictory to the mechanical response law of the shaft workpiece 8 during the torque testing process. Specifically, from the perspective of the adaptation relationship between the clamping force and the state of the shaft workpiece 8, the fixed clamping force cannot match the dynamic requirements throughout the test: when the initial clamping force is set too large, the contact stress between the clamping mechanism 3 and the surface of the shaft workpiece 8 will exceed the surface tolerance limit of the workpiece material; according to the contact stress theory in material mechanics, this excess stress will cause plastic deformation or even micro-cracks on the surface of the shaft workpiece 8, damaging the original internal structural integrity of the shaft workpiece 8. The core of the torque test is to obtain the true mechanical parameters of the shaft workpiece 8 under torsional load (such as yield torque, ultimate torque, etc.), and the pre-damage to the internal structure of the shaft workpiece 8 will change its stress distribution state, making the position and value of the stress concentration point during the test deviate from the actual working condition, ultimately leading to distorted test data and failing to reflect the true torsional resistance of the shaft workpiece 8.

[0054] When the initial clamping force is set too small, the static friction force between the clamping mechanism 3 and the shaft workpiece 8 is not enough to balance the gradually increasing torsional moment during the test. According to the friction force formula, the maximum value of the static friction force is proportional to the normal pressure (i.e. clamping force). In the torque test, as the torsional angle increases, the torsional moment borne by the shaft workpiece 8 shows an increasing trend, and accordingly, the friction force required to maintain the relative static state between the shaft workpiece 8 and the clamping mechanism 3 also needs to increase synchronously. However, the static friction force under fixed clamping force has an upper limit, and when the torsional moment exceeds this upper limit, relative sliding (i.e. slipping) will occur between the shaft workpiece 8 and the clamping mechanism 3. This slipping not only causes the sudden unloading of the test force, interrupting the test process, but also generates an impact load due to the sudden change in friction force during the slipping moment. According to the law of momentum, the impact load will generate a transient stress peak on the shaft workpiece 8 and the clamping mechanism 3, which may cause secondary damage to the shaft workpiece 8 or precision deviation of the test equipment, further affecting the effectiveness and safety of the test.

[0055] Based on this, in the torsion testing device provided by the embodiment of the application, the mounting ring 201 is arranged on the inner side wall of the mounting seat 2, the end face of the mounting ring 201 is arranged vertically, and the axis extends horizontally along the front-rear direction; the clamping mechanism 3 is arranged to include the first sleeve 301, the first sleeve 301 is coaxially inserted into the mounting ring 201 during installation, and the first sleeve 301 located on the left side is rotationally connected with the mounting ring 201, and the first sleeve 301 located on the right side is fixedly connected with the mounting ring 201; the second sleeve 302 is threadedly sleeved at the inner end of the first sleeve 301, and the clamping sleeve 303 is inserted into the second sleeve 302; the shaft workpiece 8 is inserted into the clamping sleeve 303 at the shaft end during installation, and is clamped by the clamping sleeve 303; a plurality of deformation holes 3031 are arranged through the circumferential wall side wall of the clamping sleeve 303, the deformation holes 3031 are in a strip structure and extend along a direction parallel to the axis of the clamping sleeve 303, the plurality of deformation holes 3031 are divided into two groups, the two groups of deformation holes 3031 are alternately arranged in the circumferential direction, one group of deformation holes 3031 penetrates the outer end face of the clamping sleeve 303, and the other group of deformation holes 3031 penetrates the inner end face of the clamping sleeve 303, so that the clamping sleeve 303 can expand and contract in the circumferential direction, and the clamping force on the shaft workpiece 8 can be changed subsequently.

[0056] In the second sleeve 302, the first ring table 3021 is integrally formed on the inner circumferential wall at the inner end thereof, a plurality of insertion grooves 30211 are arranged in the circumferential direction on the inner circumferential wall of the first ring table 3021, and a plurality of insertion protrusions 3032 are integrally formed on the outer circumferential wall of the clamping sleeve 303, the insertion protrusions 3032 are arranged on the strip-shaped part of the clamping sleeve 303 and are inserted into the insertion grooves 30211 during installation, so that the clamping sleeve 303 can move synchronously along the axial direction with the second sleeve 302 and can rotate synchronously with the second sleeve 302.

[0057] The guide protrusion 3033 is integrally formed on the outer side wall of each strip-shaped part of the clamping sleeve 303, the guide protrusion 3033 is in a protruding structure and has one high point and one low point, the high point is arranged more inward than the low point, the guide sleeve 304 is inserted between the clamping sleeve 303 and the second sleeve 302, the guide sleeve 304 is located outside the high point of the guide protrusion 3033, the inner circumferential wall of the guide sleeve 304 is a conical surface and is arranged with a small opening facing inward, and when the clamping sleeve 303 moves outward, the guide sleeve 304 can be guided in cooperation with the guide protrusion 3033, so that the clamping sleeve 303 can be contracted and the shaft workpiece 8 can be clamped.

[0058] In order to drive the first sleeve 301 on the left to rotate, a second ring table 3011 is integrally formed on the outer end inner wall of the first sleeve 301 on the left; the torsion test device is further provided with a driving motor 7, the driving motor 7 is inserted into the mounting seat 2 on the left, the motor shaft is towards the middle part of the base 1, and is fixed on the second ring table 3011 through bolts, so as to drive the first sleeve 301 on the left to rotate.

[0059] It can be understood that a hydraulic motor can also be used to replace the driving motor 7 to drive the first sleeve 301 on the left to rotate.

[0060] After the shaft workpiece 8 is inserted into the two clamping sleeves 303 on both ends, the two second sleeves 302 are rotated respectively, the second sleeve 302 is moved outward while rotating, the second sleeve 302 drives the clamping sleeve 303 to move outward while rotating through the insertion and connection between the insertion convex 3032 and the insertion groove 30211; when the guide convex 3033 and the tapered ring surface of the guide sleeve 304 are in contact, with the continuous movement of the second sleeve 302, the clamping sleeve 303 is contracted under the pushing of the tapered ring surface of the guide sleeve 304, the shaft end of the shaft workpiece 8 is clamped, and appropriate clamping force is ensured, so that the internal structure of the shaft workpiece 8 is not damaged due to excessive clamping force, and the accuracy of the torsion test result is ensured.

[0061] Then the driving motor 7 is started, the driving motor 7 drives the first sleeve 301 on the left to rotate, the first sleeve 301 drives the second sleeve 302 to rotate through the threaded connection between the first sleeve 301 and the second sleeve 302, the second sleeve 302 drives the clamping sleeve 303 to rotate through the insertion and connection between the insertion convex 3032 and the insertion groove 30211, and the clamping sleeve 303 drives the left end of the shaft workpiece 8 to rotate, so as to test the torsion of the shaft workpiece 8.

[0062] During the torsion test, the rotating direction of the first sleeve 301 on the left is opposite to the tightening direction of the second sleeve 302, for example, the rotating direction of the first sleeve 301 on the left is counterclockwise, and the tightening direction of the second sleeve 302 is clockwise. Figure 4As shown, the first sleeve 301 drives the left end of the shaft workpiece 8 to rotate in the counterclockwise direction through the second sleeve 302 and the clamping sleeve 303, so that the shaft workpiece 8 bears a continuously increasing torsional moment, and then the shaft workpiece 8 has a tendency to drive the second sleeve 302 to rotate in the clockwise direction through the clamping sleeve 303. At this time, since the rotation directions of the first sleeve 301 and the second sleeve 302 located on the left side are opposite, the second sleeve 302 will move outward relative to the first sleeve 301, and under the pushing of the conical surface of the guide sleeve 304, the clamping sleeve 303 continues to shrink, so that the clamping force on the shaft workpiece 8 gradually increases, which adapts to the increasing torsional moment of the shaft workpiece 8, and ensures the stability of clamping and the smooth progress of testing.

[0063] At the same time, with the rotation of the shaft workpiece 8, the second sleeve 302 and the first sleeve 301 located on the right side have a tendency to be screwed, so as to ensure the clamping stability of the right end of the shaft workpiece 8.

[0064] In other embodiments, in order to expand the function of the torsion test device and improve the applicability, the number of guide sleeves 304 inserted between the clamping sleeve 303 and the second sleeve 302 is two, the two guide sleeves 304 are arranged in parallel and spaced apart in the front-rear direction, the small ends of the two guide sleeves 304 are both towards the guide convex 3033, the guide convex 3033 has one high point and two low points, and the two low points are respectively located on the two sides of the high point, so as to ensure that the guide convex 3033 can form a guide cooperation with the two guide sleeves 304; the number of driving motors 7 is two, and each is located in the two mounting seats 2, so as to facilitate driving the two first sleeves 301 to rotate in opposite directions.

[0065] In use, after the two ends of the shaft workpiece 8 are clamped by the two clamping sleeves 303, the two driving motors 7 are started, the rotation directions of the two driving motors 7 are opposite, and the directions are periodically switched, so that the rotation directions of the two first sleeves 301 are opposite and the directions are periodically switched. The first sleeve 301 drives the second sleeve 302 to rotate through the thread cooperation between the first sleeve 301 and the second sleeve 302, and the second sleeve 302 synchronously drives the clamping sleeve 303 to rotate through the plug-in cooperation between the plug convex 3032 and the plug groove 30211. The two clamping sleeves 303 synchronously drive the two ends of the shaft workpiece 8 to rotate in opposite directions, and the directions are periodically switched, so as to realize the torsional fatigue test of the shaft workpiece 8.

[0066] When the rotation direction of the first sleeve 301 and the screwing direction of the second sleeve 302 are opposite, taking the rotation direction of the first sleeve 301 located on the left side as counterclockwise and the screwing direction of the second sleeve 302 as clockwise as an example, Figure 4As shown, the first sleeve 301 drives the left end of the shaft workpiece 8 to rotate in the counterclockwise direction through the second sleeve 302 and the clamping sleeve 303, so that the shaft workpiece 8 bears a continuously increasing torsional moment, and then the shaft workpiece 8 has a tendency to drive the second sleeve 302 to rotate in the clockwise direction through the clamping sleeve 303. At this time, since the rotation direction of the first sleeve 301 located on the left side is opposite to that of the second sleeve 302, the second sleeve 302 will move outward relative to the first sleeve 301. Under the pushing of the conical surface of the guide sleeve 304, the clamping sleeve 303 continues to shrink, so that the clamping force on the shaft workpiece 8 gradually increases, adapting to the increasing torsional moment of the shaft workpiece 8, which not only ensures the stability of clamping, but also ensures the smooth progress of testing.

[0067] When the rotation direction of the first sleeve 301 and the tightening direction of the second sleeve 302 are the same, taking the rotation direction of the first sleeve 301 located on the left side as the clockwise direction and the tightening direction of the second sleeve 302 as the clockwise direction as an example, as shown in Figure 4 When the first sleeve 301 located on the left side rotates, the first sleeve 301 and the second sleeve 302 will loosen. At this time, the shaft workpiece 8 keeps the second sleeve 302 stationary through the clamping sleeve 303. With the rotation of the first sleeve 301, the second sleeve 302 drives the clamping sleeve 303 to move inward through the thread cooperation between the first sleeve 301 and the second sleeve 302. When the guide convex 3033 contacts the conical surface of the guide sleeve 304 located on the inner side, with the continuous movement of the second sleeve 302, the clamping sleeve 303 shrinks under the pushing of the conical surface of the guide sleeve 304, and clamps the shaft end of the shaft workpiece 8. With the continuously increasing torsional moment borne by the shaft workpiece 8, the shaft workpiece 8 has a tendency to drive the second sleeve 302 to rotate in the counterclockwise direction through the clamping sleeve 303. At this time, since the rotation direction of the first sleeve 301 located on the left side is opposite to that of the second sleeve 302, the second sleeve 302 will continue to move outward relative to the first sleeve 301. Under the pushing of the conical surface of the guide sleeve 304, the clamping sleeve 303 continues to shrink, so that the clamping force on the shaft workpiece 8 gradually increases, adapting to the increasing torsional moment of the shaft workpiece 8, which not only ensures the stability of clamping, but also ensures the smooth progress of testing.

[0068] In further embodiments, to improve the clamping stability of the shaft workpiece 8 during the torsion fatigue test, a third sliding groove 3041 is formed on the outer peripheral wall of each guide sleeve 304, and the third sliding groove 3041 extends in a direction parallel to the axis of the guide sleeve 304; two guide bars 3012 are integrally formed on the inner peripheral wall of each first sleeve 301, the two guide bars 3012 are arranged in the axial direction, the guide bar 3012 extends in a direction parallel to the axis of the first sleeve 301, and is slidably inserted into the third sliding groove 3041 during installation, so that the guide sleeve 304 can slide in the axial direction; the cross section of the third sliding groove 3041 can be formed as a spade-shaped structure, and the small opening faces outward, such as a trapezoidal shape, so that the guide sleeve 304 can be guided in the sliding direction, and the freedom of the guide sleeve 304 in the radial direction can be limited by the self-narrowing structure.

[0069] It can be understood that, to realize the axial sliding of the guide sleeve 304, the guide bar 3012 can also be arranged on the outer peripheral wall of the guide sleeve 304, and the third sliding groove 3041 can be arranged on the inner peripheral wall of the first sleeve 301.

[0070] It can be understood that, to improve the stability of the axial sliding of the guide sleeve 304, a plurality of third sliding grooves 3041 can be arranged on each guide sleeve 304, and arranged in the circumferential direction; the number of guide bars 3012 on each first sleeve 301 is twice the number of third sliding grooves 3041, and is divided into two groups, the two groups of guide bars 3012 are arranged in the axial direction, the plurality of guide bars 3012 in the same group are arranged in the circumferential direction, and respectively form a sliding fit with the plurality of third sliding grooves 3041 on the same guide sleeve 304.

[0071] A gap 3042 is formed on the end face of each guide sleeve 304 facing the guide convex 3033, the positions of the two gaps 3042 on the two guide sleeves 304 on the same side correspond in the circumferential direction, a connecting seat 305 is hingedly connected at each gap 3042, the two connecting seats 305 on the same side are collectively hingedly connected by an intermediate seat 306, an adjusting rod 307 is arranged on the intermediate seat 306, the adjusting rod 307 extends outwardly in the radial direction of the first sleeve 301, penetrates through the first sleeve 301, and is threadedly connected with the first sleeve 301, the adjusting rod 307 can rotate around its own axis, and can slide in the radial direction of the first sleeve 301 through the thread connection with the first sleeve 301; a wing plate 3013 is integrally formed on the outer circumferential wall of the first sleeve 301, the wing plate 3013 is in a circular arc structure and coaxially arranged with the first sleeve 301; a bevel 3071 is integrally formed on the outer end of the adjusting rod 307; a sleeve ring 202 is integrally formed on the inner end face of each mounting ring 201, the sleeve ring 202 is coaxially arranged with the mounting ring 201, an adjusting ring 4 is fixedly and insertingly arranged in each sleeve ring 202, the adjusting ring 4 is coaxially arranged with the sleeve ring 202, a first sliding groove 401 is formed on the end face of each adjusting ring 4, the first sliding groove 401 is in an arc structure and staggered arranged at both ends in the radial direction of the adjusting ring 4, and a sliding block 5 is slidingly and insertingly arranged in each first sliding groove 401, the sliding block 5 can be stopperingly connected with the wing plate 3013, and when the first sleeve 301 rotates, the sliding block 5 can be driven by the wing plate 3013 to move along the circumferential direction of the first sliding groove 401 and move inwardly, and the sliding block 5 can be guideingly connected with the bevel 3071.

[0072] As shown in Figure 10 when the sliding block 5 and the bevel 3071 abut, the force F of the adjusting rod 307 on the sliding block 5 extends outwardly in the direction perpendicular to the bevel 3071, at this time, the force F is decomposed into a horizontal component F1 and a vertical component F2, F1=F*sinθ, F2=F*cosθ, wherein F1 is a driving force, which shows a tendency to drive the sliding block 5 to slide along the first sliding groove 401, F2 is a resistance, which shows a tendency to hinder the sliding block 5 from sliding along the first sliding groove 401, and can be equivalent to the normal pressure between the sliding block 5 and the adjusting ring 4, assuming that the friction coefficient between the sliding block 5 and the adjusting ring 4 is μ, in order to ensure that the sliding block 5 and the bevel 3071 abut and the sliding block 5 remains stationary, F1 must be less than F2*μ, which is expanded as F*sinθ<F*cosθ*μ, and after simplification, μ>tanθ, so that the sliding block 5 can remain stationary when the sliding block 5 and the bevel 3071 abut by setting the materials of the sliding block 5 and the adjusting ring 4 or changing the size of θ.

[0073] According to the principle of action and reaction, the force of the sliding block 5 on the adjusting rod 307 extends inwardly in the direction perpendicular to the bevel 3071, thereby driving the adjusting rod 307 to rotate.

[0074] Initially, the slider 5 is located at the outer end of the first sliding groove 401.

[0075] During use, when the rotation direction of the first sleeve 301 is opposite to the tightening direction of the second sleeve 302, the first sleeve 301 drives the slider 5 to move along the circumference and move inward through the wing plate 3013; and the greater the angle of torsion of the shaft workpiece 8, the greater the angle of rotation of the first sleeve 301, the farther the slider 5 moves, and the more inwardly it is arranged.

[0076] When the rotation direction of the first sleeve 301 is the same as the tightening direction of the second sleeve 302, during the rotation of the first sleeve 301, the slider 5 is arranged inwardly, which drives the adjusting rod 307 to rotate inwardly through the guiding cooperation between the slider 5 and the adjusting rod 307, the adjusting rod 307 synchronously drives the middle seat 306 to move inwardly, and the middle seat 306 synchronously drives the two guide sleeves 304 to move closer to each other through the two connecting seats 305; when the guide convex 3033 and the guide sleeve 304 abut, since the guide sleeve 304 moves inwardly by a certain distance, along with the movement of the clamping sleeve 303, the inward contraction degree is greater, so that the compensation amount of the clamping force can be adjusted according to the maximum torsional moment of the shaft workpiece 8, and the clamping stability is ensured.

[0077] In further embodiments, in order to improve the use reliability of the torsion test device, two notches 3042 are arranged on each guide sleeve 304, and are arranged at an angle of 180 degrees along the circumference, and each notch 3042 is hingedly connected with a connecting seat 305, so that there are eight connecting seats 305; the number of middle seats 306 is four, and each is hingedly connected with two adjacent connecting seats 305; the number of adjusting rods 307 is four, and each is arranged on a middle seat 306; the number of first sliding grooves 401 arranged on each adjusting ring 4 is two, and is arranged at an angle of 180 degrees along the circumference; each first sliding groove 401 is slidably inserted with a slider 5, so as to form a guiding cooperation with two adjusting rods 307 in the same circumference, and improve the stability when adjusting the distance between the two guide sleeves 304.

[0078] In other embodiments, in order to save labor when the adjusting rod 307 is reset, an elastic member is connected between each middle seat 306 and the first sleeve 301, which can be a tension spring 308. Under the action of the tension spring 308, the middle seat 306 and the adjusting rod 307 have a tendency to move outwardly, so as to save labor.

[0079] In other embodiments, in order to improve the stability of the shaft workpiece 8 during testing, a support frame 6 is arranged on the top of the base 1. The support frame 6 has a bottom plate 601 which is in a strip-shaped structure and horizontally extends along the left-right direction. Two vertical rods 602 are arranged on the top of the bottom plate 601 and extend along the vertical direction. The two vertical rods 602 are horizontally arranged side by side and spaced apart along the left-right direction. A support plate 603 is sleeved on the two vertical rods 602. When the shaft workpiece 8 is installed, the circumferential side wall of the shaft workpiece 8 abuts against the top of the support plate 603, so as to realize stable support of the shaft workpiece 8.

[0080] In further embodiments, in order to improve the versatility of the support frame 6, the support plate 603 is arranged to be sleeved on the vertical rod 602 in a sliding manner. A nut is threadedly sleeved on each vertical rod 602 and supports the bottom of the support plate 603, so that the height of the support plate 603 can be adjusted by the nut, thereby adapting to shaft workpieces 8 of different diameters.

[0081] In other embodiments, in order to improve the support flexibility of the support frame 6, the bottom plate 601 of the support frame 6 is arranged to be slidably inserted into the second sliding groove 101 during installation, so as to adjust the support position of the support frame 6 on the shaft workpiece 8.

[0082] In other embodiments, in order to further improve the stability of the shaft workpiece 8 during testing, the number of support frames 6 is multiple. The multiple support frames 6 are arranged side by side and spaced apart along the front-rear direction, so as to realize multi-point support of the shaft workpiece 8.

[0083] Illustratively, the number of support frames 6 can be two.

[0084] In other embodiments, in order to further improve the clamping stability of the clamping sleeve 303 on the shaft workpiece 8, a plurality of friction protrusions 3034 are integrally formed on the inner circumferential wall of each strip-shaped portion of the clamping sleeve 303. The plurality of friction protrusions 3034 are arranged at equal intervals along the axial direction. The friction protrusions 3034 are in contact with the circumferential side wall of the shaft workpiece 8 during use, so as to increase the friction force between the clamping sleeve 303 and the shaft workpiece 8 by increasing the friction coefficient, thereby realizing more stable clamping of the shaft workpiece 8.

[0085] In other embodiments, in order to facilitate disassembly and assembly of the torsion test device, the first sleeve 301 is arranged to be in a split structure along the axial direction, and a wing plate 3013 is arranged on each split structure. The two split structures are connected together by the wing plate 3013 and the bolt and nut assembly during installation.

[0086] Another embodiment of the present application also provides a test method of the torsion test device, which adopts any of the torsion test devices described above, and comprises the following steps:

[0087] S1, adjusting the distance between the two mounting seats 2 to have a preset distance;

[0088] Specifically, the preset distance is set to be greater than the axial length of the shaft workpiece 8, so as to facilitate the placement of the shaft workpiece 8 between the two mounting seats 2.

[0089] S2, inserting one end of the shaft workpiece 8 into the first clamping sleeve 303, and then tightening the second sleeve 302 corresponding to the first clamping sleeve 303;

[0090] Specifically, when the second sleeve 302 rotates, the clamping sleeve 303 is driven to rotate and move outward simultaneously through the insertion fit between the insertion protrusion 3032 and the insertion groove 30211; when the guide protrusion 3033 and the tapered ring surface of the guide sleeve 304 are in contact, with the continuous movement of the second sleeve 302, the clamping sleeve 303 is retracted under the push of the tapered ring surface of the guide sleeve 304, so as to clamp the shaft end of the shaft workpiece 8.

[0091] S3, adjusting the distance between the two mounting seats 2, so that the other end of the shaft workpiece 8 is inserted into the second clamping sleeve 303, and then tightening the second sleeve 302 corresponding to the second clamping sleeve 303;

[0092] Specifically, the clamping principle of the other end of the shaft workpiece 8 is the same as above, and will not be described again.

[0093] S4, driving one of the first sleeves 301 to rotate to test the torsion of the shaft workpiece 8.

[0094] Specifically, the first sleeve 301 is driven to rotate by the driving motor 7, the second sleeve 302 is driven to rotate by the thread cooperation between the first sleeve 301 and the second sleeve 302, the clamping sleeve 303 is driven to rotate by the insertion fit between the insertion protrusion 3032 and the insertion groove 30211 of the second sleeve 302, and the left end of the shaft workpiece 8 is driven to rotate by the clamping sleeve 303, so as to test the torsion of the shaft workpiece 8.

[0095] The technical features of the above embodiments can be combined arbitrarily, and in order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0096] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A torsion testing device, characterized by, The torsion testing device comprises a base frame, two mounting seats oppositely arranged on the base frame, the distance between the two mounting seats being adjustable, a clamping mechanism arranged on each mounting seat, the clamping mechanism comprising a first sleeve, a second sleeve threadedly sleeved on the first sleeve, a clamping sleeve inserted in the second sleeve, the clamping sleeve being capable of moving synchronously with the second sleeve along the axial direction, being capable of rotating synchronously with the second sleeve, and being capable of expanding and contracting along the circumferential direction, the clamping sleeve being configured to clamp a shaft workpiece, a guide sleeve inserted between the clamping sleeve and the second sleeve, the guide sleeve and the clamping sleeve forming a guide fit to enable the clamping sleeve to contract and clamp the shaft workpiece, and one of the first sleeves being capable of rotating about its own axis in a direction opposite to the tightening direction of the second sleeve. The number of the guide sleeves inserted between the clamping sleeve and the second sleeve is two, the two guide sleeves being oppositely arranged and each being capable of forming a guide fit with the clamping sleeve, and the two first sleeves each being capable of rotating about its own axis in a direction opposite to the other. The guide sleeve is capable of sliding along the axial direction, each guide sleeve is hingedly connected with a connecting seat, two connecting seats in the same first sleeve are collectively hingedly connected with an intermediate seat, the intermediate seat is provided with an adjusting rod, the adjusting rod is capable of rotating about its own axis, penetrates the first sleeve along the radial direction, and forms a threaded fit with the first sleeve, each first sleeve is sleeved with an adjusting ring, each adjusting ring is provided with a first sliding groove, a sliding block is slidably inserted in the first sliding groove, and the sliding block is capable of forming a stop fit with the first sleeve and a guide fit with the adjusting rod. The number of the connecting seats in the same first sleeve is multiple, the number of the intermediate seats and the adjusting rods is equal to twice the number of the connecting seats and is arranged along the circumferential direction, and the number of the first sliding grooves provided on each adjusting ring is multiple and is arranged along the circumferential direction, and the sliding block is slidably inserted in each first sliding groove.

2. The torsion testing device of claim 1, wherein, The intermediate seat and the first sleeve are connected with an elastic member, and the intermediate seat has a tendency to move outward under the action of the elastic member.

3. The torsion testing device of claim 1, wherein, The base frame is further provided with a support frame, and the support frame is configured to support the shaft workpiece.

4. The torsion testing device of claim 3, wherein, The height of the support surface of the support frame is adjustable.

5. The torsion testing device of claim 3, wherein, The support frame is capable of sliding along the axial direction of the shaft workpiece.

6. The torsion testing device of claim 3, wherein, The number of the support frames is multiple, and the multiple support frames are arranged along the axial direction of the shaft workpiece.

7. A test method of a torsion test device, characterized by, The torsion testing method using the torsion testing device of claim 1 comprises the following steps: S1, adjusting the distance between the two mounting seats to a preset distance; S2, inserting one end of the shaft workpiece into the first clamping sleeve, and then tightening the second sleeve corresponding to the first clamping sleeve; S3, adjusting the distance between the two mounting seats so that the other end of the shaft workpiece is inserted into the second clamping sleeve, and then tightening the second sleeve corresponding to the second clamping sleeve; S4, drive one of the first sleeve to rotate, the shaft workpiece torsion test.

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