Abnormal sound test bench with composite degree-of-freedom excitation

Abstract

The invention provides a compound degree-of-freedom excited abnormal sound test bench. The compound degree-of-freedom excited abnormal sound test bench comprises a base, a supporting frame, an objective table, a first limiting piece, a second limiting piece and a driving mechanism, the supporting frame is provided with a first mounting part, the bottom of the objective table is provided with a second mounting part and two driving connecting parts, and one side edge of the objective table is provided with a third mounting part; the first limiting piece comprises a rod body and two first elastic parts, and the first mounting part and the second mounting part are connected with the two ends of the rod body through the first elastic parts correspondingly; the second limiting piece comprises an extension arm and a mounting seat, the mounting seat comprises a second elastic part, and the two ends of the extension arm are connected with the second elastic part and the third mounting part respectively; the driving mechanism comprises two driving end heads, and each driving end head is connected with one driving connecting part. The first limiting piece and the second limiting piece are used for supporting, limiting and guiding the objective table, composite degree-of-freedom excitation can be achieved only through z-direction exciting force, operation is convenient, and the testing effect is good.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle detection, and in particular to an abnormal noise test bench with compound degree of freedom excitation. Background Art

[0002] In recent years, car abnormal noise has attracted more and more attention. As we all know, cars are assembled from several parts, and abnormal noise of parts is an important part of the whole car abnormal noise. Nowadays, major parts and car manufacturers pay great attention to the abnormal noise of parts, and usually use test methods to determine whether parts have abnormal noise.

[0003] At present, when simulating the interaction between vehicles on actual roads, component vibration test benches are mostly equipped with driving mechanisms that can provide X, Y, and Z excitation forces respectively, so that the tested components vibrate in the front and rear, left and right, and vertical directions in turn. However, there are many changes in the movement mode during the driving process of the car, and the vibration direction of the components is not always in the X, Y, and Z directions. As a result, the results obtained by single-degree-of-freedom testing of components cannot be well matched with the actual scene. For this reason, technicians often need to verify the X, Y, and Z directions separately for multiple times to achieve the best fit. This testing method takes a lot of time and is not able to restore the real scene to a high degree. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an abnormal sound test bench with compound degree of freedom excitation, which can simulate the vibration of the vehicle in the direction of compound degrees of freedom to solve the problem of insufficient restoration of real scenes in single degree of freedom testing in the prior art and can improve detection efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A noise test bench for compound degree of freedom excitation, characterized in that it includes a base, a support frame, a stage, a first limiter, a second limiter and a driving mechanism; the support frame is provided with a first mounting portion, the bottom of the stage in the z direction is provided with a second mounting portion and two driving connection portions arranged in the y direction, and a third mounting portion is provided on an x-direction side of the stage; the first limiter includes a rod body arranged in the y direction and two first elastic components located at both ends of the rod body, and the first mounting portion and the second mounting portion are respectively connected to the two ends of the rod body through the first elastic component; the second limiter includes an extension arm and a mounting seat, the mounting seat includes a base fixedly connected to the base and a second elastic component arranged on the upper side of the base, and the two ends of the extension arm respectively form a lower connection portion that can be connected to the second elastic component and an upper connection portion that can be connected to the third mounting portion, and the center point of the upper connection portion and the center point of the lower connection portion are on the same xz plane; the driving mechanism includes two driving ends arranged in the y direction that can vibrate in the z direction, and each driving end is connected to a driving connection portion.

[0006] Furthermore, the first elastic component includes a first positioning member and a first elastic connecting member, the first positioning member is fixedly connected to the first mounting portion / the second mounting portion, and the first positioning member forms an elastic abutment with the end of the rod body through the first elastic connecting member.

[0007] Furthermore, the rod body can rotate on a plane parallel to the y-direction with the first elastic connecting member as the center.

[0008] Furthermore, the first limit member also includes two adjustment components arranged at both ends of the rod body, the adjustment components include a connecting screw and an adjustment block, the connecting screw is coaxially arranged and fixedly connected to the rod body, a connecting screw hole that can be movably matched with the connecting screw is formed in the middle of the adjustment block, and the first elastic fast elastically abuts against the adjustment block.

[0009] Furthermore, the first limiting member also includes an inner end packaging plate, an outer end packaging plate and a packaging sleeve, the first positioning member also includes a penetration portion arranged in the middle, the inner end packaging plate is fixedly connected to the end of the rod body, a penetration hole is formed in the middle of the outer end packaging plate for the penetration of the penetration portion, a plurality of packaging connection holes are provided near the edge of the inner end packaging plate and the outer end packaging plate, and the two ends of the packaging sleeve are respectively fixedly connected to the inner end packaging plate and the outer end packaging plate.

[0010] Furthermore, the second elastic component includes a second positioning member and a second elastic connecting member, the second positioning member is fixedly connected to the base, and the second positioning member forms an elastic abutment with the lower connecting portion through the second elastic connecting member.

[0011] Furthermore, the extension arm can rotate on a plane parallel to the z-direction with the second positioning member as the center.

[0012] Furthermore, the extension arm includes a main connecting arm and two symmetrically arranged branch connecting arms, the first end of the main connecting arm is connected to the second elastic component, and the second end extends along an xz plane toward the extension platform, the branch connecting arm is connected to the second end of the main connecting arm and extends toward the platform, an angle is formed between the two branch connecting arms, and the third mounting portion includes two mounting areas corresponding to the branch connecting arms.

[0013] Furthermore, the support frame includes a support column connected to the base, a support substrate connected to the upper end of the support column, and a plurality of support airbags arranged along the y-direction on the upper side of the support substrate, the first limiting member is arranged at a position close to the x-direction side edge where the third mounting portion is provided, and the support airbags are arranged at a position close to another x-direction side edge.

[0014] In summary, the application of the present invention can achieve the following beneficial effects: 1. The present invention utilizes a first limit member and a second limit member to support and limit the loading platform. The first limit member and the second limit member are connected by a first elastic component and a second elastic component, which play a limiting and guiding role in the movement of the loading platform. When the two driving ends are excited in the same direction, the movement state of the loading platform is a rotation centered on the second elastic component on the xz plane, and the movement state is formed by a combination of x-direction and z-direction movements. When the two driving ends vibrate in opposite directions, the movement state of the loading platform is a rotation centered on the first elastic component on the yz plane, and the movement state is formed by a combination of y-direction and z-direction movements, thereby realizing the excitation of the composite degree of freedom of the loading platform and being able to better simulate actual road conditions.

[0015] 2. The first elastic component and the second elastic component provided in the present invention enable the loading platform to vibrate in multiple degrees of freedom while playing a limiting role. The first elastic component will not hinder the occurrence of pitch vibration, and the second elastic component will not hinder the occurrence of roll vibration. There is no need to disassemble and assemble parts during the switching process of pitch and roll tests, which is easy to operate and efficient.

[0016] 3. In some embodiments, the present invention is further provided with a support airbag, which can assist in bearing weight, and the first limit member and the support airbag can be respectively arranged at positions close to and away from the third mounting portion, thereby reducing the length of the force arm between the first limit member and the second elastic member, thereby reducing the influence of the first limit member on the pitch vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the abnormal noise test bench with compound degree of freedom excitation in the embodiment; Figure 2 for Figure 1 Side view of Figure 3 for Figure 1 Rear view of Figure 4 for Figure 1 A schematic structural diagram of the first limiting member; Figure 5 for Figure 1 A schematic diagram of the structure of the second limiting member; Figure 6 is a schematic structural diagram of a second position-limiting member in another embodiment; In the figure: 1- Base; 2-support frame, 21-support column, 22-support base plate, 23-first mounting portion, 24-support airbag; 3- stage, 31- second mounting part, 32- driving connection part, 33- third mounting part; 4-first position-limiting member, 41-rod body, 42-first elastic member, 43-connecting screw, 44-adjusting block, 45-inner end packaging plate, 46-outer end packaging plate, 47-packaging sleeve; 5-second position-limiting member, 51-extension arm, 511-main connecting arm, 512-branch connecting arm, 513-lower connecting part, 514-upper connecting part, 52-mounting seat, 521-base, 522-second elastic member; 6-driving mechanism, 61-driving end, 62-driving connecting rod. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0019] Reference Figures 1 to 6 The present embodiment provides an abnormal noise test bench with compound degree of freedom excitation, which can realize compound degree of freedom excitation of components by controlling the driving mode to make the tested components rotate and vibrate in the xz plane or in the yz plane, so as to better simulate the actual road conditions and facilitate the study of the formation mode of abnormal noise. Specifically, the abnormal noise test bench includes the following structure: The base 1 is fixedly connected to the foundation when in use and provides a stable installation base for other structures; in some embodiments, the base may include a large flat plate unit, and other structures of the abnormal sound test bench are assembled based on the large flat plate unit. In other embodiments, the base may also include a plurality of independent small flat plate units, each of which provides an installation base for a corresponding structure. Usually, the flat plate unit is provided with a plurality of fixing holes, some of which are used to fix the flat plate unit to the foundation structure, and other fixing holes are used to connect the flat plate unit to parts of the abnormal sound test bench; The support frame 2 is fixedly connected to the upper side of the base 1 to play a supporting and overhead role; the support frame includes a support column 21 vertically connected to the flat plate unit of the base and a support base plate 22 connected to the upper end of the support column and arranged horizontally when in use, and a first mounting portion 23 is fixedly connected to the upper side of the support base plate, and the first mounting portion includes a first mounting plate and a second mounting plate connected at right angles to each other, the first mounting plate is attached to the support base plate and is detachably fixedly connected by screws, the second mounting plate is arranged parallel to the xz plane, and the second mounting plate is provided with a first positioning hole that passes through the y direction; in this embodiment, the support frame includes two relatively independent support units symmetrically arranged in the xz plane, and a spacing is left between the two support units, each support unit includes a support base plate and two support columns, and the third mounting portion is arranged above the support base plate of one of the support units; The stage 3 is suspended on the upper side of the support frame 2 and is used for placing and fixing the components to be tested; the stage includes a stage body. In the present embodiment, the stage body is roughly a rectangular parallelepiped structure, which includes two x-direction side surfaces, two y-direction side surfaces and two z-direction side surfaces. The z-direction bottom surface of the stage body is connected with a second mounting portion 31 and two drive connection portions 32, and an x-direction side edge of the stage body is provided with a third mounting portion 33; the second mounting portion includes a third mounting plate and a fourth mounting plate connected at right angles to each other, the third mounting plate and the z-direction bottom surface of the stage body are detachably fixedly connected by screws, the fourth mounting plate is arranged parallel to the xz plane, the fourth mounting plate is provided with a second positioning hole which passes through in the y-direction, the drive connection portion is provided with a drive connection hole which opens in the z-direction, and the third mounting portion is provided with a plurality of mounting holes opened based on the stage body; The first limiting member 4 is used to connect the loading platform 3 and the support frame 2, and plays a supporting and guiding role; the first limiting member includes a rod body 41, two first elastic components 42 arranged at both ends of the rod body, and an adjusting component arranged between the rod body and the first elastic component; the first elastic component includes a first positioning member 421 and a first elastic connecting member 422. At the first end position of the rod body, the corresponding first positioning member is fixedly connected to the second mounting plate of the first mounting part through the first positioning hole, and the first positioning member forms an elastic abutment with the end of the rod body 41 through the first elastic connecting member. At the two end positions, the corresponding first positioning member is fixedly connected to the fourth mounting plate of the second mounting part through the second positioning hole, and the first positioning member forms an elastic abutment with the end of the rod body 41 through the first elastic connecting member, and the elastic abutment structure enables the rod body 41 to rotate on a plane parallel to the y direction with the first elastic connecting member 422 as the center; the adjusting component includes a connecting screw 43 and an adjusting block 44, the connecting screw 43 is coaxially arranged with the rod body 41, the connecting screw is fixedly connected to the end of the rod body, and a connecting screw hole that can be movably matched with the connecting screw is formed in the middle of the adjusting block. In the assembled state, the first side of the first elastic member elastically abuts against the adjusting block through the first elastic block, and is then connected to the rod body 41 through the connecting screw 43, and the second side is fixedly connected to the second mounting plate or the fourth mounting plate through the internal connecting hole; The second limiting member 5 is used to connect the stage 3 and the base 1, and plays a supporting and guiding role; the third limiting member includes an extension arm 51 and a mounting seat 52, the mounting seat includes a base 521 fixedly connected to the base and a second elastic component 522 arranged on the upper side of the base, the two ends of the extension arm respectively form a lower connecting portion 513 and an upper connecting portion 514, the center position of the upper connecting portion and the center position of the lower connecting portion are in the same xz plane, the lower connecting portion can be sleeved and fixed on the outer periphery of the elastic sleeve, and the upper connecting portion can be detachably fixedly connected with the third mounting portion 33 by screws, the second elastic component includes a second positioning member and a second elastic connecting member, the second positioning member is fixedly connected to the base 521, and the second positioning member forms an elastic abutment with the lower connecting portion 513 through the second elastic connecting member, and the extension arm 51 can rotate on a plane parallel to the z direction with the second positioning member as the center; The driving mechanism 6 includes two driving ends 61, which are arranged on the lower side of the worktable and arranged in the y direction. Each driving end is connected to a power source that can provide an exciting force and enable the driving end to vibrate in the z direction. The driving end is fixedly connected to the driving connecting part 32 in the z direction through a driving connecting rod 62, so that the z-direction vibration generated by the driving end can act on the worktable.

[0020] The working principle of the present invention is as follows: in a first working state, the two driving ends are controlled by a power source to vibrate in the same direction, and the driving ends provide a z-direction exciting force to the loading platform, so that the loading platform undergoes periodic lifting and lowering vibrations. The second limiting member provided by the present invention limits an x-direction side edge of the loading platform, and the second limiting member can utilize the deformation of the elastic sleeve to rotate around the mounting axis on any axial cross-section of the mounting axis, but cannot undergo a single z-direction movement. Because the center position of the upper connecting part of the extension arm and the center position of the lower connecting part are in the same xz plane, the integrated assembly formed by the fixed connection between the loading platform and the second limiting member will rotate on the xz plane around the mounting axis after being subjected to the z-direction exciting force. In a second working state, the two driving ends are controlled by a power source to vibrate asynchronously, and the driving ends provide periodic z-direction exciting force to the y-upward sides of the loading platform in turn, so that the y-upward sides of the loading platform Lifting vibration occurs in sequence, and the first limiter provided by the present invention provides a limiting effect on the loading platform, and the end of the rod body is connected to the first mounting part or the second mounting part through the first elastic component. Between the rod body and the first mounting part, the rod body can rotate on the yz plane with the first elastic component as the center, and between the rod body and the loading platform, the loading platform can rotate on the yz plane with the first elastic component as the center; taking a driving scene as an example, a protrusion is provided in front of the vehicle, and when the front wheel of the vehicle passes through the protrusion, the front wheel of the vehicle is lifted, and the rear wheel remains unchanged. At this time, the entire body of the vehicle is pitched with the rear wheel as the fulcrum, and the pitch vibration is similar to the first working state of the present invention; taking another driving scene as an example, a protrusion is provided in front of the right side of the vehicle, and when the right wheel passes through the protrusion, the right wheel of the vehicle is lifted, and the left wheel remains unchanged. At this time, the entire body of the vehicle is roll-vibrated with the left wheel as the fulcrum, and the roll vibration is similar to the second working state of the present invention. In summary, the present invention can simulate the composite degree of freedom vibration during vehicle driving by only providing an exciting force in the z direction, thereby improving the abnormal sound detection effect. In principle, under the joint action of the first limiter and the second limiter, when the stage calibrated to the original position enters into vibration from rest, its vibration direction should always be along the yz plane. After the vibration occurs, if the overall position of the stage rises or falls, it will tend to move along the xz plane under the action of the second limiter. In the present invention, during the roll test, since the forces provided by the two exciters are in opposite directions, the stage as a whole is not considered to be lifted, and therefore the vibration direction during the test is along the yz plane. In the pitch test, the forces provided by the two exciters are in the same direction, and the stage as a whole will rise or fall, and at this time the vibration direction will be along the xz plane. Therefore, the present invention can realize the simulation of the above two composite degrees of freedom.

[0021] However, from an extreme perspective, when the amplitude of vibration is extremely small, the position movement of the stage can be ignored from a macroscopic perspective and can be regarded as moving along the yz plane. For the present invention, the above-mentioned "the center point of the upper connecting part and the center point of the lower connecting part are on the same xz plane" can be realized by a variety of embodiments. In the first embodiment, the extension arm is a straight line structure extending from the xz plane. At this time, the two ends of the extension arm must be on the same xz plane, but this connection method makes the extension arm and the stage have only one connection point, and the stability during pitch vibration is insufficient; in the second embodiment, referring to Figure 5 The extension arm includes a main connecting arm 511 and two branch connecting arms 512. The first end of the main connecting arm is provided with a lower connecting portion 513 and is connected to the mounting seat 52, and the second end extends straightly along the xz plane toward the stage. The first end of the branch connecting arm is connected to the main connecting arm, and the second end is provided with an upper connecting portion 514 and is connected to the third mounting portion. An angle is formed between the two branch connecting arms. The two branch connecting arms are symmetrically arranged based on the xz plane where the main connecting arm extends. In this embodiment, although the two branch connecting arms are each provided with an upper connecting portion, since the two branch connecting arms are symmetrically arranged, the center positions of the two upper connecting portions are still in the same xz plane as the lower connecting portion. In this embodiment, since there are two connection points between the extension arm and the stage, the stability during pitch vibration is stronger; in the third embodiment, refer to Figure 6 The structure of the extension arm is the same as that of the first embodiment, except that the second limit member includes two extension arms arranged in parallel and symmetrically, and each of the two extension arms is connected to a mounting seat 52. The effect is similar to that of the second embodiment, but the second embodiment is more advantageous in terms of cost and space occupancy, and during the roll vibration test, the resistance generated by the second embodiment is smaller than that of the third embodiment.

[0022] In other embodiments of the present invention, the stage body is not limited to a rectangular structure, its z-direction bottom surface is not limited to being parallel to the xy plane, and the third mounting plate and the fourth mounting plate of the second mounting portion are not limited to being perpendicular to each other. However, it is required that the first / second positioning holes on the second mounting plate and the fourth mounting plate are both y-direction openings to ensure the fixed installation of the first elastic member, and the x-direction side surface of the stage body is not limited to being parallel to the yz plane. It is only required that the x-direction side surface can be matched and connected with the upper connecting portion of the second limiting member.

[0023] In some other embodiments of the present invention, the support frame 2 further includes a plurality of support airbags 24, the upper ends of the support airbags are connected to the z-direction bottom surface of the stage, and the lower ends are connected to the upper plane of the support substrate, the plurality of support airbags are arranged in the y-direction, and the first limit member is arranged at a position close to the x-direction side of the third mounting portion, the support airbag is arranged at a position close to the x-direction side where the third mounting portion is not arranged, and the drive connection portion is arranged between the support airbag and the first limit member. Under this mounting structure, on the one hand, the support airbag can assist in supporting the stage to make the stage more stable and reduce the pressure on the first limit member. On the other hand, the distance between the first limit member and the second elastic member is small, and when the stage performs pitch vibration, the length of the force arm between the first limit member and the second elastic member is small, and the hindrance to the pitch motion is small.

[0024] It should also be noted that the directional limitations of each structure in the present application are described based on the initial state of the abnormal sound test bench when it is assembled and not in operation. Since multiple components of the abnormal sound test bench are in motion during operation, it does not meet the above directional limitations at all times, but only needs to be met in a certain specific position.

[0025] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A noise test bench with compound degree of freedom excitation, characterized by: The invention comprises a base (1), a support frame (2), a loading platform (3), a first position-limiting member (4), a second position-limiting member (5) and a driving mechanism (6); the support frame is provided with a first mounting portion (23); the bottom of the loading platform in the z direction is provided with a second mounting portion (31) and two driving connection portions (32) arranged in the y direction; a side of the loading platform in the x direction is provided with a third mounting portion (33); the first position-limiting member comprises a rod body (41) arranged in the y direction and two first elastic components (42) located at both ends of the rod body; the first mounting portion and the second mounting portion are respectively connected to both ends of the rod body through the first elastic components. The second limiting member comprises an extension arm (51) and a mounting seat (52), the mounting seat comprises a base (521) fixedly connected to the base and a second elastic component (522) arranged on the upper side of the base, the two ends of the extension arm respectively form a lower connecting portion (513) that can be connected to the second elastic component and an upper connecting portion (514) that can be connected to the third mounting portion, and the center point of the upper connecting portion and the center point of the lower connecting portion are located in the same xz plane; the driving mechanism comprises two driving ends (61) arranged in the y direction and capable of vibrating in the z direction, each driving end being connected to a driving connecting portion.

2. The abnormal noise test bench with compound degree of freedom excitation according to claim 1 is characterized by: The first elastic component (42) comprises a first positioning member and a first elastic connecting member, the first positioning member is fixedly connected to the first mounting portion / the second mounting portion, and the first positioning member forms an elastic abutment with the end of the rod body (41) via the first elastic connecting member.

3. The abnormal noise test bench with compound degree of freedom excitation according to claim 2 is characterized by: The rod body (41) can rotate on a plane parallel to the y direction with the first elastic connecting member as the center.

4. The abnormal noise test bench with compound degree of freedom excitation according to claim 2 is characterized by: The first position-limiting member further comprises two adjustment components arranged at both ends of the rod body, the adjustment components comprising a connecting screw (43) and an adjustment block (44), the connecting screw being coaxially arranged with the rod body and fixedly connected thereto, a connecting screw hole being formed in the middle of the adjustment block and being capable of movably cooperating with the connecting screw, and the first elastic block being in elastic contact with the adjustment block.

5. The noise test bench with compound degree of freedom excitation according to claim 2 is characterized by: The first limiting member also includes an inner end packaging plate (45), an outer end packaging plate (46) and a packaging sleeve (47), and the first positioning member also includes a penetration portion arranged in the middle, the inner end packaging plate is fixedly connected to the end of the rod body, a penetration hole is formed in the middle of the outer end packaging plate for the penetration of the penetration portion, a plurality of packaging connection holes are provided near the edges of the inner end packaging plate and the outer end packaging plate, and the two ends of the packaging sleeve are respectively fixedly connected to the inner end packaging plate and the outer end packaging plate.

6. The abnormal noise test bench with compound degree of freedom excitation according to claim 1 is characterized by: The second elastic component comprises a second positioning member and a second elastic connecting member, the second positioning member is fixedly connected to the base (521), and the second positioning member forms an elastic abutment with the lower connecting portion (513) via the second elastic connecting member.

7. The abnormal noise test bench with compound degree of freedom excitation according to claim 6 is characterized by: The extension arm (51) can rotate on a plane parallel to the z-direction with the second positioning member as the center.

8. The abnormal noise test bench with compound degree of freedom excitation according to claim 1 is characterized by: The extension arm comprises a main connecting arm (511) and two symmetrically arranged branch connecting arms (512), wherein the first end of the main connecting arm is connected to the second elastic component and the second end extends in the direction of the extension platform along an xz plane, the branch connecting arm is connected to the second end of the main connecting arm and extends in the direction of the platform, an angle is formed between the two branch connecting arms, and the third mounting portion comprises two mounting areas corresponding to the branch connecting arms.

9. The abnormal noise test bench with compound degree of freedom excitation according to claim 1 is characterized by: The support frame comprises a support column (21) connected to the base, a support base plate (22) connected to the upper end of the support column, and a plurality of support airbags (24) arranged along the y direction and disposed on the upper side of the support base plate, wherein the first stopper is disposed at a position close to an x-direction side edge where a third mounting portion is disposed, and the support airbags are disposed at a position close to another x-direction side edge.

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