A device for testing the natural frequency of a vibration damping system and a method of testing the same

Abstract

The present application relates to the technical field of automobile testing, and discloses a natural frequency testing device of a damping system and a testing method thereof, which comprises a base, a lifting assembly, a controller and a test bed for bearing the whole vehicle, the test bed is located above the base, the side of the base facing the test bed is provided with a bearing surface, and the base is provided with a placing cavity with an opening facing the test bed and used for accommodating the lifting device; the lifting assembly comprises a first state and a second state, when the lifting assembly is in the first state, the upper end of the lifting assembly protrudes from the bearing surface, the test bed is lifted by the lifting assembly, and the test bed has a falling distance from the bearing surface; when the lifting assembly is in the second state, the upper end of the lifting assembly is lower than or flush with the bearing surface, the test bed is in contact with the bearing surface, and the base supports the test bed; and the lifting assembly is electrically connected with the controller. The natural frequency testing device of the damping system and the testing method thereof improve the accuracy of the test results and perform the natural frequency testing of the simultaneous falling of multiple wheels.

Description

Technical Field

[0001] This invention relates to the technical field of automotive testing, and in particular to a device and method for testing the natural frequency of a vibration damping system. Background Technology

[0002] Currently, commercial vehicles, needing to balance cargo transport integrity and passenger comfort, generally employ multi-stage vibration damping, where the chassis suspension system and cab mounts are connected in series for damping. Therefore, testing the natural frequencies of each damping system in a commercial vehicle under full-vehicle conditions presents certain challenges. One current method for measuring the natural frequencies of a commercial vehicle's overall vibration damping system is the roll-off method, such as... Figure 5 As shown.

[0003] The roll-off test involves driving a car up a ramp onto a test bench, parking it, shifting it to neutral, and turning off the engine. The vehicle is then slowly pushed off the bench, and a recorder captures the free decay time signals of vibrations in the cab, chassis, and axles. However, this method requires the vehicle to continue moving forward after the roll-off, necessitating braking to stop, which affects the accuracy of the test results. Furthermore, it cannot perform natural frequency testing on multiple wheels rolling off simultaneously. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. It provides a natural frequency testing device and method for a vibration damping system, improves the accuracy of test results, and performs natural frequency testing of multiple wheels falling simultaneously.

[0005] To achieve the above objectives, the present invention provides a natural frequency testing device for a vibration reduction system, comprising a base, a lifting assembly, a controller, and a test bench for supporting the entire vehicle. The test bench is located above the base, and the base has a bearing surface on the side facing the test bench. The base has an opening facing the test bench for accommodating a placement cavity for the lifting assembly.

[0006] The lifting assembly includes a first state and a second state. When the lifting assembly is in the first state, the upper end of the lifting assembly protrudes from the bearing surface, and the lifting assembly lifts the test platform. There is a drop gap A between the test platform and the bearing surface.

[0007] When the lifting assembly is in the second state, the upper end of the lifting assembly is lower than or flush with the bearing surface, the test bench is in contact with the bearing surface, and the base supports the test bench;

[0008] The lifting assembly is electrically connected to the controller and is used for switching between the first state and the second state.

[0009] As a preferred embodiment, the natural frequency testing device further includes a failure link for handling the failure of the vibration damping element in the vibration damping system, wherein the connection positions at both ends of the failure link are the same as the connection positions at both ends of the vibration damping element.

[0010] As a preferred embodiment, the lifting assembly includes multiple synchronously operating lifting drive components, connecting pipes, and valve bodies. The multiple lifting drive components are respectively connected to the valve bodies through the connecting pipes. The valve bodies are electrically connected to the controller. The lifting drive components are installed in the placement cavity.

[0011] As a preferred embodiment, the valve body is a one-way valve.

[0012] As a preferred embodiment, the lifting drive component is driven by hydraulic pressure.

[0013] As a preferred embodiment, the test bench is provided with guide ramps at both ends, and the lower end of the guide ramps extends toward the base.

[0014] As a preferred embodiment, the base is provided with a limiting groove on the side facing the test bench, and when the lifting assembly is in the second state, the test bench is located in the limiting groove.

[0015] As a preferred embodiment, the drop gap A is set at 60mm-90mm.

[0016] A method for testing the natural frequency of a vibration damping system, using a vibration damping system natural frequency testing device, includes the following steps:

[0017] The entire test vehicle is located on the test bench;

[0018] Vibration monitoring devices for collecting vibration data are installed in the vehicle as needed.

[0019] The lifting assembly moves the test platform away from the bearing surface, creating a drop distance between the test platform and the bearing surface.

[0020] The lifting assembly is lowered by the controller, and the test bench falls and impacts the bearing surface.

[0021] As a preferred embodiment, the vehicle includes a first component, a second component, and a damping system for cushioning the first and second components. The damping system comprises at least two of a front axle suspension, a middle axle suspension, a rear axle suspension, a front suspension assembly, and a rear suspension assembly. The natural frequency testing device further includes a failure link for handling the failure of the damping element. Before the test bench is dropped, the two ends of the failure link are respectively connected to the first component and the second component of the damping system that do not need to be tested.

[0022] This invention discloses a natural frequency testing device and method for a vibration reduction system. Compared with existing technologies, its advantages include: a base that provides overall foundation support, and the base itself can be the ground. A test bench supports the entire vehicle for natural frequency testing, and the vehicle remains on the test bench throughout the testing process. A lifting assembly lifts the test bench, creating a drop gap between the test bench and the base. A controller controls the lifting and lowering of the lifting assembly. The base has a placement cavity with an opening facing the test bench. The lifting assembly is installed in the placement cavity, positioned below the test bench to lift it. The lifting assembly includes a first state and a second state. In the first state, the lifting assembly lifts the test bench carrying the vehicle, creating a drop gap between the test bench and the base's bearing surface, preparing for the test bench's fall. Before the test bench falls, vibration monitoring devices are installed on the vehicle as needed to collect vibration data. The controller rapidly retracts the lifting assembly, causing the test bench to descend quickly. A vibration monitoring device records data on the vehicle's stability before descent, the descent process, and the free decay of each vibration damping system after descent. This data is then analyzed to obtain natural frequency data. Because the vehicle does not need to roll off the test bench during testing, it avoids movement and braking along the descent direction, improving the accuracy of the test results. Furthermore, since the entire vehicle is positioned on the test bench during testing, the vibration decay when all wheels fall simultaneously can be measured. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention in the first state.

[0024] Figure 2 This is a schematic diagram of the overall structure of an embodiment of the present invention in the second state.

[0025] Figure 3 This is a schematic diagram of the structure of the rear axle suspension with the failure link installed in an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the front suspension assembly with the failure linkage installed in an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the overall structure of existing technology.

[0028] In the picture:

[0029] 10. Base; 11. Bearing surface; 12. Placement cavity; 13. Limiting groove;

[0030] 20. Lifting assembly; 21. Lifting drive unit; 22. Connecting pipe; 23. Valve body;

[0031] 30. Controller;

[0032] 40. Test bench; 41. Guide ramp;

[0033] 50. Failed connecting rod; 51. First through hole; 52. Second through hole; 53. First fixing seat; 54. Second fixing seat;

[0034] 60. Vehicle; 61. Cab; 62. Body; 63. Axle; 64. Wheel;

[0035] 70. Front axle suspension; 71. Middle axle suspension; 72. Rear axle suspension; 73. Front suspension assembly; 74. Rear suspension assembly. Detailed Implementation

[0036] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0037] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0038] In the description of this invention, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] like Figures 1 to 4 As shown, a natural frequency testing device for a vibration reduction system according to a preferred embodiment of the present invention includes a base 10, a lifting assembly 20, a controller 30, and a test bench 40 for supporting the entire vehicle 60. The test bench 40 is located above the base 10. The base 10 has a bearing surface 11 on the side facing the test bench 40. The base 10 has an opening facing the test bench 40 and a placement cavity 12 for accommodating the lifting device.

[0040] The lifting assembly 20 includes a first state and a second state, such as Figure 1As shown, when the lifting assembly 20 is in the first state, the upper end of the lifting assembly 20 protrudes from the bearing surface 11, and the lifting assembly 20 lifts the test bench 40. There is a drop gap A between the test bench 40 and the bearing surface 11.

[0041] like Figure 2 As shown, when the lifting assembly 20 is in the second state, the upper end of the lifting assembly 20 is lower than or flush with the bearing surface 11, the test bench 40 is in contact with the bearing surface 11, and the base 10 supports the test bench 40.

[0042] The lifting assembly 20 is electrically connected to the controller 30 for switching between the first and second states.

[0043] In the natural frequency testing device of the vibration reduction system of the present invention, the base 10 is the overall foundation support, and the base 10 can also be the ground. The test bench 40 is used to support the entire vehicle 60 for natural frequency testing, and the vehicle 60 remains on the test bench 40 throughout the testing process. The lifting assembly 20 is used to lift the test bench 40, so that a drop gap is formed between the test bench 40 and the base 10. The controller 30 is used to control the lifting and lowering of the lifting assembly 20. The base 10 has a placement cavity 12 with an opening facing the test bench 40, and the lifting assembly 20 is installed in the placement cavity 12, so that the lifting assembly 20 is located below the test bench 40 to lift the test bench 40. The lifting assembly 20 includes a first state and a second state. When the lifting assembly 20 is in the first state, the lifting assembly 20 lifts the test bench 40 carrying the vehicle 60, so that a drop gap is formed between the test bench 40 and the bearing surface 11 of the base 10, preparing for the drop of the test bench 40. Before the test bench 40 is dropped, vibration monitoring devices are installed on the vehicle 60 as needed to collect vibration data. The lifting assembly 20 is rapidly retracted via the controller 30, causing the test bench 40 to descend quickly. The vibration monitoring devices record the stable state before the drop, the drop process, and the free attenuation process of each vibration damping system of the vehicle after the drop. The data is then tested and analyzed to obtain natural frequency data. Since the vehicle 60 does not need to roll off the test bench 40 during the test, movement and braking along the direction of rolling off the test bench 40 are avoided, improving the accuracy of the test results. Simultaneously, because the entire vehicle is positioned on the test bench 40 during testing, the vibration attenuation when each wheel 64 drops simultaneously can be tested.

[0044] Furthermore, such as Figures 3 to 4As shown, the natural frequency testing device also includes a failure link 50 for handling the failure of damping elements in the damping system. The connection positions at both ends of the failure link 50 are the same as the connection positions at both ends of the damping element. The two ends of the failure link 50 are connected to the connection positions at both ends of the damping element to keep the damping element in its initial state during the test. The failure link 50 makes the damping element a rigid connection, causing the relevant damping system to fail. In the case of multiple damping systems in a vehicle, this device can test some of the damping systems, avoiding mutual interference between multiple damping systems and the inability to obtain the natural frequency of a single or partial damping system.

[0045] Specifically, vehicle 60 includes a cab 61, a body 62, an axle 63, a suspension assembly, and a suspension system. Both the suspension assembly and the suspension system are damping systems. The two ends of the damping system are connected to a first component and a second component, respectively. The suspension assembly includes a front suspension assembly 73 and a rear suspension assembly 74. The two ends of the damping elements of the suspension assembly are connected to the cab 61 and the body 62, respectively. When the damping system is a suspension assembly, the first component is the cab 61 and the second component is the body 62. The suspension system includes at least two of the following: a front axle suspension 70, a middle axle suspension 71, and a rear axle suspension 72. The two ends of the damping elements of the suspension are connected to the body 62 and the axle 63, respectively. The axle 63 is connected to the wheel 64. When the damping system is a suspension system, the first component is the vehicle body and the second component is the axle 63.

[0046] Furthermore, such as Figures 1 to 2 As shown, the lifting assembly 20 includes multiple synchronously operating lifting drive components 21, connecting pipes 22, and valve bodies 23. The multiple lifting drive components 21 are connected to the valve bodies 23 via the connecting pipes 22. The valve bodies 23 are electrically connected to the controller 30. The lifting drive components 21 are installed in the placement cavity 12. The placement cavity 12 limits the lifting drive components 21 circumferentially to prevent them from falling over and ensure their normal operation along the height direction. The lifting drive components 21 drive the test bench 40 to rise. The medium transmits pressure to the lifting drive components 21 through the connecting pipes 22. The valve bodies 23 control the opening and closing of the connecting pipes 22, and the controller 30 controls the opening and closing of the connecting pipes 22 through the valve bodies 23. The multiple lifting drive components 21 are evenly distributed below the test bench 40 to ensure more even force distribution on the test bench 40.

[0047] In one embodiment, the number of lifting drive components 21 is even, and the lifting drive components 21 are arranged symmetrically along the axis of symmetry, the direction of which is the forward direction of the car on the test bench 40.

[0048] Furthermore, such as Figures 1 to 2As shown, valve body 23 is a one-way valve, simplifying control. When the test bench 40 is lifted, hydraulic oil flows through the input pipe 22 and the one-way valve to the lifting drive component 21, causing the drive end of the lifting drive component 21 to extend upwards. When the test bench 40 falls, the controller 30 opens the one-way valve, allowing hydraulic oil to flow out through the output pipe 22, enabling the test bench 40 to fall rapidly. All valve bodies 23 are controlled by the controller 30 to maintain a consistent state of the lifting drive component 21.

[0049] Furthermore, the lifting drive component 21 is driven by hydraulic pressure. Hydraulic systems can accommodate relatively high-power components.

[0050] Furthermore, such as Figures 1 to 2 As shown, the test bench 40 has guide ramps 41 at both ends. The lower end of the guide ramps 41 extends toward the base 10. When the vehicle 60 moves from the base 10 to the test bench 40, it is connected and guided by the guide ramps 41, making the vehicle 60 move more smoothly.

[0051] Furthermore, a limiting groove 13 is provided on the side of the base 10 facing the test bench 40. When the lifting component 20 is in the first state, the test bench 40 is located above the corresponding limiting groove 13. When the lifting component 20 is in the second state, the test bench 40 is located in the limiting groove 13, ensuring that the test bench 40 is located in the limiting groove 13 after falling, preventing the test bench 40 from shifting and improving the safety of use. At the same time, the limiting groove 13 ensures the relative position of the test bench 40 and the lifting component 20, ensuring that the lifting component 20 is located below the corresponding test bench 40.

[0052] Furthermore, such as Figure 1 As shown, the drop gap A is set at 60mm-90mm so that the vehicle 60 vibrates when it falls with the test bench 40, and the vibration monitoring instrument placed on the vehicle 60 collects the vibration data.

[0053] A method for testing the natural frequency of a vibration damping system, such as Figures 1 to 4 As shown, the test is conducted using a natural frequency testing device for the vibration reduction system, including the following steps:

[0054] The test vehicle 60 is positioned on the test bench 40 to ensure that all vibration damping systems in the vehicle 60 are within the testing range;

[0055] Vibration monitoring devices for collecting vibration data are deployed as needed in vehicle 60. The vibration monitoring devices and their deployment methods are existing technologies. Vibration monitoring devices are also used in existing test schemes. The vibration monitoring devices can be deployed as needed for installation and testing.

[0056] The lifting assembly 20 moves the test bench 40 away from the bearing surface 11. The lifting assembly 20 is in the first state, so that there is a drop distance between the test bench 40 and the bearing surface 11.

[0057] The lifting assembly 20 is rapidly lowered under the control of the controller 30. The vehicle 60 falls synchronously with the test bench 40 and impacts the bearing surface 11, causing the vibration damping system on the vehicle 60 to vibrate. The vibration monitoring instrument records the stable state before the fall, the fall process, and the free decay process of each vibration damping system of the entire vehicle after the fall. The test data is analyzed to obtain the natural frequency data. Since the vehicle 60 falls vertically during the test, horizontal movement is avoided, improving the accuracy of the test results. At the same time, since all the vibration damping systems of the vehicle 60 are located in the test bench 40, test data on the vibration decay caused by the combined effect of all the vibration damping systems can be obtained.

[0058] Furthermore, such as Figures 3 to 4 As shown, vehicle 60 includes a first component, a second component, and a damping system for buffering the first and second components. The damping system comprises at least two of the following: front axle suspension 70, middle axle suspension 71, rear axle suspension 72, front suspension assembly 73, and rear suspension assembly 74. The natural frequency testing device also includes a failure link 50 for handling the failure of damping elements. Before the test bench 40 is dropped, both ends of the failure link 50 are connected to the first and second components of the damping system that do not need to be tested. For example, when it is necessary to test the overall natural frequency of the cab 61 and its suspension system, the failure link 50 can be fixed to the front axle suspension 70, middle axle suspension 71, and rear axle suspension 72. When it is necessary to test the natural frequency of a particular damping system, the failure link 50 can be fixed to other damping systems. When it is necessary to examine the mutual influence of the various damping systems of the entire vehicle, it is not necessary to fix the damping systems. By fixing the failure link 50 to the vibration reduction system, a portion of the vibration reduction system is rendered ineffective, allowing the natural frequency test of the vibration reduction system not connected to the failure link 50 to be performed. This enables the natural frequency test of a single or partial vibration reduction system, resulting in a more comprehensive testing scheme.

[0059] The specific first and second components differ depending on the specific vibration damping system. For example, if the vibration damping system is a suspension assembly, then the first component is the cab 61 and the second component is the body 62; if the vibration damping system is a suspension, then the first component is the body 62 and the second component is the axle 63. Both ends of the vibration damping system are connected to the first and second components respectively, achieving an elastic connection. The connection positions of both ends of the failure link 50 are the same as the connection positions of both ends of the vibration damping system. The two ends of the failure link 50 are rigidly connected to the first and second components respectively, causing the vibration damping system to fail, thereby preventing this vibration damping system from affecting the testing of other vibration damping systems.

[0060] Specifically, when the vibration damping system is a suspension assembly, the cab 61 is provided with a first fixed seat 53, the body 62 is provided with a second fixed seat 54, and the two ends of the failure linkage 50 are provided with a first through hole 51 and a second through hole 52. The first fixed seat 53 is connected to the first through hole 51 by bolts, and the second fixed seat 54 is connected to the second through hole 52 by bolts.

[0061] When the damping system is a suspension, the body 62 is provided with a first fixed seat 53, the axle 63 is provided with a second fixed seat 54, and the two ends of the failure link 50 are provided with a first through hole 51 and a second through hole 52. The first fixed seat 53 is connected to the first through hole 51 by bolts, and the second fixed seat 54 is connected to the second through hole 52 by bolts.

[0062] In summary, this invention provides a natural frequency testing device and method for a vibration reduction system. The base 10 provides overall foundation support and can also be the ground. The test bench 40 supports the entire vehicle 60 for natural frequency testing, and the vehicle 60 remains on the test bench 40 throughout the testing process. The lifting assembly 20 lifts the test bench 40, creating a drop gap between the test bench 40 and the base 10. The controller 30 controls the lifting and lowering of the lifting assembly 20. The base 10 has a placement cavity 12 with an opening facing the test bench 40. The lifting assembly 20 is installed in the placement cavity 12, positioned below the test bench 40 to lift it. The lifting assembly 20 includes a first state and a second state. In the first state, the lifting assembly 20 lifts the test bench 40 carrying the vehicle 60, creating a drop gap between the test bench 40 and the bearing surface 11 of the base 10, preparing for the test bench 40 to fall. Before the test bench 40 is dropped, vibration monitoring devices are installed on the vehicle 60 as needed to collect vibration data. The lifting assembly 20 is rapidly retracted via the controller 30, causing the test bench 40 to descend quickly. The vibration monitoring devices record the stable state before the drop, the drop process, and the free attenuation process of each vibration damping system of the vehicle after the drop. The data is then tested and analyzed to obtain natural frequency data. Since the vehicle 60 does not need to roll off the test bench 40 during the test, movement and braking along the direction of rolling off the test bench 40 are avoided, improving the accuracy of the test results. Simultaneously, because the entire vehicle is positioned on the test bench 40 during testing, the vibration attenuation when each wheel 64 drops simultaneously can be tested.

[0063] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A device for testing the natural frequency of a vibration reduction system, characterized in that: The system includes a base, a lifting assembly, a controller, and a test bench for supporting the entire vehicle. The test bench is located above the base, and the base has a bearing surface on the side facing the test bench. The base has an opening facing the test bench for accommodating a placement cavity for the lifting device. The lifting assembly includes a first state and a second state. When the lifting assembly is in the first state, the upper end of the lifting assembly protrudes from the bearing surface, and the lifting assembly lifts the test platform. There is a drop gap A between the test platform and the bearing surface. When the lifting assembly is in the second state, the upper end of the lifting assembly is lower than or flush with the bearing surface, the test bench is in contact with the bearing surface, and the base supports the test bench; The lifting assembly is electrically connected to the controller and is used for switching between the first state and the second state; The natural frequency testing device also includes a failure link for handling the failure of the vibration damping element in the vibration damping system. The connection positions at both ends of the failure link are the same as the connection positions at both ends of the vibration damping element, so that the vibration damping element is kept in the initial state during the test, and the failure link makes the vibration damping element a rigid connection. The lifting assembly includes multiple synchronously operating lifting drive components, connecting pipes, and valve bodies. The multiple lifting drive components are respectively connected to the valve bodies through the connecting pipes. The valve bodies are electrically connected to the controller. The lifting drive components are installed in the placement cavity.

2. The natural frequency testing device for the vibration reduction system according to claim 1, characterized in that: The valve body is a one-way valve.

3. The natural frequency testing device for the vibration reduction system according to claim 1, characterized in that: The lifting drive component is driven by hydraulic pressure.

4. The natural frequency testing device for the vibration reduction system according to claim 1, characterized in that: The test bench has guide ramps at both ends, with the lower end of the guide ramps extending toward the base.

5. The natural frequency testing device for the vibration reduction system according to claim 1, characterized in that: The base has a limiting groove on the side facing the test bench. When the lifting assembly is in the second state, the test bench is located in the limiting groove.

6. The natural frequency testing device for the vibration reduction system according to claim 1, characterized in that: The drop gap A is set between 60mm and 90mm.

7. A method for testing the natural frequency of a vibration reduction system, characterized in that: The test is conducted using the natural frequency testing device for the vibration reduction system according to any one of claims 1-6, including the following steps: The entire test vehicle is located on the test bench; Vibration monitoring devices for collecting vibration data are installed in the vehicle as needed. The lifting assembly moves the test platform away from the bearing surface, creating a drop distance between the test platform and the bearing surface. The controller controls the lifting assembly to descend, causing the test bench to fall and impact the bearing surface.

8. The test method for the vibration reduction system according to claim 7, characterized in that: The vehicle includes a first component, a second component, and a damping system for cushioning the first component and the second component. The damping system is at least two of a front axle suspension, a middle axle suspension, a rear axle suspension, a front suspension assembly, and a rear suspension assembly. Before the test bench is dropped, the two ends of the failed link are respectively connected to the first component and the second component at the damping system where no testing is required.

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