Cab suspension damping device, sound quality improvement method, system and engineering machinery

Abstract

The application discloses a cab suspension damping device, a sound quality improving method and system and engineering machinery. The cab suspension damping device comprises a base connected with a vehicle frame, a top plate connected with a cab bottom plate, and an intermediate platform located between the base and the top plate. The intermediate platform is connected with the top plate through a plurality of magnetorheological dampers. The intermediate platform is connected with the base through a limiting damping assembly and a plurality of variable stiffness springs. The cab suspension damping device has simple structure, good damping effect, and is easy to install and maintain. Meanwhile, the rigidity and damping of the cab suspension damping device can be adjusted in real time, the sound quality of the cab is improved, and the driving comfort and the accuracy of the driver's conversation are improved.

Description

Technical Field

[0001] This invention belongs to the field of sound quality control technology for engineering machinery, specifically relating to a cab suspension vibration damping device, a sound quality improvement method, a system, and engineering machinery. Background Technology

[0002] The noise generated by construction vehicles during operation is a significant indicator of driver fatigue. Currently, most construction machinery produces noise levels below 85 dBA. When the noise level near the driver's ear is below 70 dBA, reaching an acceptable range, auditory perception becomes dominant, and the harmful effects of noise translate into adverse physiological reactions such as fatigue, dizziness, weakness in the limbs, decreased attention and judgment, slow reaction time, and irritability. Due to the complexity of acoustic properties caused by the spectral distribution characteristics of in-vehicle noise, a single sound pressure level cannot adequately evaluate noise quality. Therefore, sound quality parameters gradually become dominant, making improvement devices and systems that enhance sound quality a primary research focus.

[0003] Currently, there are no devices or systems developed specifically to address the sound quality of the cab in engineering vehicles. Traditional solutions remain focused on reducing A-weighted sound pressure levels. Typically, FFT (Fast Fourier Transform) analysis of the noise around the driver's ear is used to identify the main components affecting A-weighting. The sound pressure level around the driver's ear is then reduced by using the vehicle's suspension damping system or by blocking airborne sound transmission gaps. However, this approach fails to meet the needs for improved sound quality and reduced subjective annoyance to the human ear. Therefore, devices and systems for improving the sound quality of the cab are of great research significance in the field of engineering vehicles. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a cab suspension vibration damping device, a sound quality improvement method, a system, and engineering machinery. The cab suspension vibration damping device has a simple structure, good vibration damping effect, and is easy to install and maintain. At the same time, it can adjust the stiffness and damping of the cab suspension vibration damping device in real time and improve the sound quality of the cab, thereby improving driving comfort and the accuracy of driver dialogue.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a cab suspension damping device is provided, comprising: a base connected to a vehicle frame; a top plate connected to a cab floor; and an intermediate platform located between the base and the top plate, wherein the intermediate platform and the top plate are connected by a plurality of magnetorheological dampers; and the intermediate platform and the base are connected by a limiting damping component and a plurality of variable stiffness springs.

[0007] Furthermore, the axis of each variable stiffness spring is perpendicular to the base and the intermediate platform, respectively, and the angle between the axis of each variable stiffness spring and the horizontal plane is an acute angle.

[0008] Furthermore, at least one of the magnetorheological dampers is vertically installed between the intermediate platform and the top plate, and the remaining magnetorheological dampers are parallel to the variable stiffness springs at their respective installation positions.

[0009] Furthermore, the limiting and damping component is connected to the intermediate platform via a ball joint, and the limiting and damping component is connected to the base via a ball joint.

[0010] Furthermore, the limiting and vibration damping assembly includes: an upper ball joint for hinged to the intermediate platform; a lower ball joint for hinged to the base; a spring installed between the upper ball joint and the lower ball joint; a sliding rod is installed on the upper ball joint, and a sleeve is installed on the lower ball joint, with one end of the sliding rod away from the upper ball joint extending into the sleeve and maintaining a set distance from the lower ball joint.

[0011] Furthermore, the spring is sleeved on the outside of the sleeve.

[0012] Furthermore, the sleeve includes a metal outer shell and a lower sleeve rubber and an upper sleeve rubber disposed on the metal outer shell by a vulcanization process.

[0013] Furthermore, the diameters of both the upper and lower ball joints are larger than the diameter of the spring.

[0014] Secondly, a method for improving the sound quality of a driver's cab is provided, based on the driver's cab suspension vibration damping device described in the first aspect. The method includes: collecting noise signals and vibration signals from the driver's cab; performing sound quality analysis based on the noise signals and vibration signals, and extracting key objective parameters; when the sound quality analysis results exceed a threshold, adjusting the stiffness and damping of the magnetorheological damper in the driver's cab suspension vibration damping device according to the extracted key objective parameters, or controlling a speaker installed in the driver's cab to play an anti-phase sound wave of the noise signal.

[0015] Furthermore, the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device are adjusted according to the extracted main objective parameters, or the speaker installed in the cab is controlled to play the anti-phase sound wave of noise. This includes: when the main objective parameter is the significance rate, that is, the sound quality analysis result exceeding the threshold is caused by the significance rate, all frequencies with a significance rate exceeding the first set value are extracted and recorded as frequency group one; all frequencies with a significance rate exceeding the first set value in the collected vibration signal are extracted and recorded as frequency group two; when the overlap between each frequency of frequency group one and each frequency of frequency group two exceeds the second set value, it is considered that the sound quality exceeding the threshold is caused by structural noise; the minimum frequency of frequency group one is extracted, and the suspension stiffness and damping corresponding to this minimum frequency are calculated; and a control command to adjust the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device is issued in real time; when the main objective parameter is other parameters, that is, the sound quality analysis result exceeding the threshold is caused by parameters other than the significance rate, the speaker installed in the cab is controlled to play the anti-phase sound wave of the noise signal.

[0016] Furthermore, the operating frequency band of the speaker is 9-17 bar.

[0017] Thirdly, a cab sound quality improvement system is provided, including the cab suspension vibration damping device described in the first aspect. The system further includes: a data acquisition module for acquiring noise signals and vibration signals from the cab; an on-board main controller for performing sound quality analysis based on the noise and vibration signals and extracting key objective parameters; and a cab sound quality active control module for adjusting the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device according to the extracted key objective parameters when the sound quality analysis results exceed a threshold, or controlling the speaker installed in the cab to play the anti-phase sound wave of the noise signal.

[0018] Fourthly, a construction machinery is provided, wherein the construction machinery is equipped with the cab sound quality improvement system described in the third aspect.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention forms a cab suspension damping device by means of a base connected to the vehicle frame; a top plate connected to the cab floor; an intermediate platform located between the base and the top plate, the intermediate platform being connected to the top plate by a number of magnetorheological dampers; and the intermediate platform being connected to the base by a limiting damping component and a number of variable stiffness springs. This device has the characteristics of simple structure, good damping effect, and easy installation and maintenance. At the same time, it can adjust the stiffness and damping of the cab suspension damping device in real time and improve the sound quality of the cab, thereby improving driving comfort and the accuracy of driver dialogue. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the overall structure of a cab suspension vibration damping device provided in an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 Exploded view;

[0022] Figure 3 This is a schematic diagram of the installation structure of the variable stiffness spring and the intermediate platform in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of the limiting and vibration damping component in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a cab equipped with a cab sound quality improvement system provided in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the main process of a method for improving the sound quality of a driver's cab provided in an embodiment of the present invention;

[0026] In the diagram: 1. Base; 2. Variable stiffness spring; 21. -X upward spring; 22. -X downward spring; 23. +X upward spring; 24. +X downward spring; 25. -Y upward spring; 26. -Y downward spring; 27. +Y upward spring; 28. +Y downward spring; 3. Limiting and damping assembly; 31. Lower ball joint; 32. Sleeve; 321. Lower sleeve rubber; 322. Upper sleeve rubber; 33. Slide rod; 34. Spring; 35. Upper ball joint; 4. Middle platform; 5. Magnetorheological damper; 6. Top plate; 10. Cab suspension damping device; 20. Vibration sensor; 30. Vehicle main controller; 40. Error microphone; 50. Speaker. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0028] Example 1:

[0029] like Figures 1-4 As shown, a cab suspension damping device includes: a base 1 connected to the vehicle frame; a top plate 6 connected to the cab floor; and an intermediate platform 4 located between the base 1 and the top plate 6, wherein the intermediate platform 4 and the top plate 6 are connected by a plurality of magnetorheological dampers 5; and the intermediate platform 4 and the base 1 are connected by a limiting damping assembly 3 and a plurality of variable stiffness springs 2.

[0030] In this embodiment, there are eight variable stiffness springs 2 and five magnetorheological dampers 5. The base 1 is located above the vehicle frame and is connected to the vehicle frame by bolts; the variable stiffness springs 2 are welded to the base 1 and the intermediate platform 4, and the angle between them and the horizontal plane is acute; the limiting and damping assembly 3 is connected to the base 1 and the intermediate platform 4 by ball joints; the magnetorheological dampers 5 are located between the intermediate platform 4 and the top plate 6, with one vertically located at the center below the top plate 6, and the other four parallel to the corresponding positions of the variable stiffness springs 2.

[0031] like Figure 3 As shown, there are eight variable stiffness springs 2, each welded to a corresponding contact platform. In the four directions (+X, -X, +Y, -Y), two variable stiffness springs are symmetrically distributed above and below the central platform 4 in each direction, with the spring axes forming a non-90-degree angle with the horizontal plane. The eight variable stiffness springs 2 specifically include: -X upward spring 21, -X downward spring 22, +X upward spring 23, +X downward spring 24, -Y upward spring 25, -Y downward spring 26, +Y upward spring 27, and +Y downward spring 28. -X upward spring 21 and -X downward spring 22 are on the same axis; similarly, +X upward spring 23 and +X downward spring 24 are also coaxial, and the same applies to the other two directions. When the frame experiences significant X-direction vibration, the frame causes the base 1 to move in the X direction. The +X downward spring 24 and -X downward spring 22 are subjected to tensile forces, while the +X upward spring 23 and -X upward spring 21 are subjected to compressive forces. The force on the +X inclined surface of the intermediate platform 4 is decomposed into the X and Z directions (the force in the X direction is twice the force of a single spring). The force on the -X inclined surface of the intermediate platform 4 is decomposed into the +X and -Z directions (the force in the X direction is twice the force of a single spring). After the decomposition, the force in the X direction is four times that of a single spring, and the Z-direction force cancels out, thus effectively reducing the X-direction vibration.

[0032] The four variable stiffness springs along the Y direction operate on the same principle as those along the X direction. When the frame experiences significant Y-direction vibration, the frame causes the base 1 to move in the Y direction. The +Y downward spring 28 and -Y downward spring 26 are subjected to tensile forces, while the +Y upward spring 27 and -Y upward spring 25 are subjected to compressive forces. The force on the +Y inclined surface of the intermediate platform 4 is decomposed into the Y and Z directions (the force in the Y direction is twice the force of a single spring). The force on the -Y inclined surface of the intermediate platform 4 is decomposed into the +Y and -Z directions (the force in the Y direction is twice the force of a single spring). After the combined force, the force in the Y direction is four times that of a single spring, and the Z-direction force cancels out, thus effectively reducing the Y-direction vibration.

[0033] like Figure 4As shown, the limiting vibration damping component 3 is the second vibration damping system. It can not only further realize vertical vibration damping, but also ensure that the second set of vibration damping system can play an effective role when the spring fails. The limiting vibration damping component 3 includes a lower ball joint 31. The spherical structure allows the sleeve 32 to rotate at any angle. The sleeve 32 is composed of two sets of rubber vulcanized with a metal shell, including a lower sleeve rubber 321 and an upper sleeve rubber 322. The two sets of rubber can ensure that when the spring fails, the conical rubber can realize vibration damping in the X, Y, and Z directions. The metal slide rod 33 is located inside the sleeve 32. The sufficient stroke distance can ensure that the slide rod 33 does not contact the sleeve 32 and the sleeve rubber when the spring is working. It will only contact the rubber when the spring assembly fails. The spring 34 is sleeved on the outside of the sleeve 32 and welded to the ball joint plane to realize vertical vibration damping. The upper ball joint 35 is connected between the intermediate platform 4 and the metal slide rod 33. The diameter of the ball joint is larger than the outer diameter of the spring 34, which can ensure that the spring 34 always works between the upper ball joint 35 and the lower ball joint 31.

[0034] The cab suspension vibration damping device described in this invention has the characteristics of simple structure, good vibration damping effect, and easy installation and maintenance. At the same time, it can adjust the stiffness and damping of the cab suspension vibration damping device in real time and improve the sound quality of the cab, thereby improving driving comfort and the accuracy of driver's dialogue.

[0035] Example 2:

[0036] Based on the cab suspension vibration damping device described in Embodiment 1, this embodiment provides a cab sound quality improvement system.

[0037] The cab sound quality improvement system includes two aspects: one is the cab suspension vibration damping device described in Embodiment 1 of the invention, which targets the significance rate of the main objective parameters; the other is the cab sound quality improvement system proposed for the remaining main objective parameters.

[0038] like Figure 5 As shown, there are four cab suspension damping devices 10 described in Embodiment 1, which are symmetrically distributed between the cab floor and the frame; the vibration sensor 20 is installed at the bottom of the cab, and the cab is equipped with an on-board main controller 30, an error microphone 40 and a speaker 50.

[0039] like Figure 6 As shown, the main processes of the cab sound quality improvement system include:

[0040] 1. Sound Quality Objective Parameter Modeling Module: The sound quality objective parameter modeling module performs objective parameter analysis on the noise signal of the cab collected by the error microphone in the cab, and establishes a multivariate regression sound quality objective parameter model through subjective evaluation (which belongs to the existing technology) to obtain the main objective parameters of the cab sound quality.

[0041] 2. Data Acquisition Module: The data acquisition module includes an error microphone in the cab, a speed sensor near the engine, and a vibration sensor on the cab vibration damping base. It mainly collects noise signals in the cab and vibration signals near the magnetorheological damper.

[0042] 3. Vehicle Main Controller: The vehicle main controller comprehensively compares and analyzes the noise and vibration signals collected by the data acquisition module. First, for the collected noise signal, real-time sound quality analysis results are obtained through the sound quality objective parameter model. Once the sound quality analysis results exceed the threshold, the main influencing objective parameters (loudness, A-weighted sound pressure level, salience, roughness, sharpness, semantic clarity, jitter, etc.) are extracted. Through correlation analysis, highly correlated objective parameters are merged and dimension-reduced. Through weight analysis, objective parameters with small weight factors are eliminated, and finally, the sound quality objective parameter model established by the most influential objective parameters is obtained. When the sound quality analysis result exceeds the threshold due to the significance rate parameter, all frequencies in the error microphone significance rate analysis that exceed the first set value (9dB) are extracted and recorded as frequency group one. All frequencies in the vibration signal collected by the vibration sensor that exceed the first set value (9dB) are extracted and recorded as frequency group two. When the overlap between each frequency in frequency group one and each frequency in frequency group two exceeds the second set value (90%), the cab suspension vibration damping device is activated. The minimum frequency in the two frequency groups is extracted (according to vibration isolation theory, if the minimum frequency can meet the vibration isolation requirements, then the vibration isolation effect of higher frequencies will be better), and the suspension stiffness and damping corresponding to this frequency are calculated. Control commands to adjust the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device are issued in real time, thereby improving the sound quality of the cab by reducing the significance rate. On the other hand, when the sound quality result exceeds the threshold due to other objective parameters, the speakers in the cab are activated, and the anti-phase sound waves emitted by the speakers further improve the sound quality of the cab.

[0043] 4. Active Sound Quality Control Module for the Cab: The active sound quality control module for the cab includes an error microphone and a speaker installed in the cab. Sound quality is analyzed based on the values ​​collected by the error microphone. If the sound quality exceeds a threshold due to other objective parameters exceeding limits, the onboard speaker will activate. The onboard speaker operates in the human ear's sensitive frequency range of 9-17 bar. The waveform collected by the microphone is fed back to the speaker in real time, generating an inverse sound wave to further improve the sound quality of the cab.

[0044] The sound quality improvement system of this invention employs a newly invented vibration isolation device, which combines a variable stiffness spring vibration damping component, a rubber vibration isolation and limiting component, and a magnetorheological damper. It not only provides primary variable stiffness vibration damping but also achieves secondary rubber vibration damping and limiting after spring failure. The variable damping magnetorheological damper effectively reduces the resonance amplitude. The cab sound quality improvement system is equipped with an error microphone, vibration sensor, tachometer, and speaker. It promptly extracts objective parameters when sound quality exceeds a threshold, matches them with vibration results in real time to adjust the stiffness and damping of the vibration isolation device, and adjusts the speaker output waveform within a suitable Bark range based on loudness results, thereby improving the sound quality of the cab.

[0045] This embodiment also provides a method for improving the sound quality of a driver's cab, based on the driver's cab suspension vibration damping device described in Embodiment 1. The method includes:

[0046] Collect noise and vibration signals from inside the cab;

[0047] Sound quality analysis is performed based on noise and vibration signals, and key objective parameters are extracted.

[0048] When the sound quality analysis results exceed the threshold, the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device are adjusted according to the extracted main objective parameters, or the speaker installed in the cab is controlled to play the anti-phase sound wave of the noise signal, including:

[0049] When the main objective parameter is the significance rate, that is, the sound quality analysis result exceeding the threshold is caused by the significance rate, all frequencies with a significance rate exceeding the first set value (9dB) are extracted and recorded as frequency group one. All frequencies with a significance rate exceeding the first set value (9dB) in the collected vibration signal are extracted and recorded as frequency group two. When the overlap between each frequency of frequency group one and each frequency of frequency group two exceeds the second set value (90%), it is considered that the sound quality exceeding the threshold is caused by structural noise. The minimum frequency of frequency group one is extracted, and the suspension stiffness and damping corresponding to this minimum frequency are calculated. Control commands to adjust the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device are issued in real time.

[0050] When the main objective parameter is other parameters, that is, the sound quality analysis result exceeding the threshold is caused by parameters other than the significance rate, the speaker installed in the cab is controlled to play the anti-phase sound wave of the noise signal; the operating frequency band of the speaker is 9-17 bar.

[0051] Example 3:

[0052] Based on the cab sound quality improvement system described in Embodiment 2, this embodiment provides a piece of construction machinery equipped with the cab sound quality improvement system described in Embodiment 2.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A driver's cab suspension vibration damping device, characterized in that, include: Base (1) that connects to the frame; Top plate (6) connected to the cab floor; An intermediate platform (4) is located between the base (1) and the top plate (6), wherein the intermediate platform (4) and the top plate (6) are connected by a plurality of magnetorheological dampers (5); the intermediate platform (4) and the base (1) are connected by a limiting vibration damping assembly (3) and a plurality of variable stiffness springs (2). The axis of each variable stiffness spring (2) is perpendicular to the base (1) and the intermediate platform (4), and the angle between the axis of each variable stiffness spring (2) and the horizontal plane is an acute angle. At least one of the magnetorheological dampers (5) is vertically installed between the intermediate platform (4) and the top plate (6), and the remaining magnetorheological dampers (5) are parallel to the variable stiffness springs (2) at their respective installation positions.

2. The cab suspension vibration damping device according to claim 1, characterized in that, The limiting and damping component (3) is connected to the intermediate platform (4) by a ball joint, and the limiting and damping component (3) is connected to the base (1) by a ball joint.

3. The cab suspension vibration damping device according to claim 2, characterized in that, The limiting and damping component (3) includes: Upper ball joint (35) for hinged to the intermediate platform (4); Lower ball joint (31) for hinged to the base (1); A spring (34) is installed between the upper ball joint (35) and the lower ball joint (31); A slide rod (33) is installed on the upper ball joint (35), and a sleeve (32) is installed on the lower ball joint (31). The end of the slide rod (33) away from the upper ball joint (35) extends into the sleeve (32) and maintains a set distance from the lower ball joint (31).

4. The cab suspension vibration damping device according to claim 3, characterized in that, The spring (34) is sleeved on the outside of the sleeve (32).

5. The cab suspension vibration damping device according to claim 3, characterized in that, The sleeve (32) includes a metal shell and a lower sleeve rubber (321) and an upper sleeve rubber (322) disposed on the metal shell by a vulcanization process.

6. The cab suspension vibration damping device according to claim 3, characterized in that, The diameters of the upper ball joint (35) and the lower ball joint (31) are both larger than the diameter of the spring (34).

7. A method for improving the sound quality of a driver's cab, characterized in that, Based on the cab suspension vibration damping device according to any one of claims 1 to 6, the method includes: Collect noise and vibration signals from inside the cab; Sound quality analysis is performed based on noise and vibration signals, and key objective parameters are extracted. When the sound quality analysis results exceed the threshold, the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device are adjusted according to the extracted main objective parameters, or the speaker installed in the cab is controlled to play the anti-phase sound wave of the noise signal.

8. The method for improving the sound quality of the driver's cab according to claim 7, characterized in that, Adjusting the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device based on the extracted main objective parameters, or controlling the speaker installed in the cab to play the anti-phase sound wave of noise, including: When the main objective parameter is the significance rate, that is, the sound quality analysis result exceeding the threshold is caused by the significance rate, all frequencies whose significance rate exceeds the first set value are extracted and recorded as frequency group one. All frequencies whose significance rate frequency exceeds the first set value in the collected vibration signal are extracted and recorded as frequency group two. When the overlap between each frequency of frequency group one and each frequency of frequency group two exceeds the second set value, it is considered that the sound quality exceeding the threshold is caused by structural noise. The minimum frequency of frequency group one is extracted, and the suspension stiffness and damping corresponding to this minimum frequency are calculated. Control commands to adjust the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device are issued in real time. When the main objective parameter is other than the parameter, that is, the sound quality analysis result exceeding the threshold is caused by a parameter other than the significance rate, the speaker installed in the cab is controlled to play the anti-phase sound wave of the noise signal.

9. The method for improving the sound quality of the driver's cab according to claim 8, characterized in that, The speaker operates in the 9-17 bar frequency range.

10. A cab sound quality improvement system, characterized in that, The system, comprising the cab suspension damping device according to any one of claims 1 to 6, further comprises: The data acquisition module is used to collect noise signals and vibration signals from inside the cab. The vehicle-mounted main controller is used to perform sound quality analysis based on noise and vibration signals and extract key objective parameters. The cab sound quality active control module is used to adjust the stiffness and damping of the magnetorheological damper in the cab suspension vibration damping device according to the extracted main objective parameters when the sound quality analysis results exceed the threshold, or to control the speakers installed in the cab to play the anti-phase sound wave of the noise signal.

11. An engineering machinery, characterized in that, The construction machinery is equipped with the cab sound quality improvement system as described in claim 10.

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