A vibration isolation structure for automobile hydraulic suspension

Abstract

The present invention relates to a vibration isolation structure of an automobile hydraulic suspension, comprising a shell, a first cavity being arranged in the shell, a decoupling diaphragm disc module and a flow channel sleeved on the decoupling diaphragm disc module being arranged in the first cavity, the outer wall of the flow channel being interference fit with the inner wall of the cavity; the decoupling diaphragm disc module comprising an outer frame, a decoupling diaphragm disc, an upper limit structure, a lower limit structure and vibration-damping rubber; the lower limit structure is U-shaped and is arranged at the bottom in a second cavity, the upper frame is arranged at the top in the second cavity, the decoupling diaphragm disc is arranged between the upper limit structure and the lower limit structure; the vibration-damping rubber is fixedly arranged between the lower limit structure and the side frame; the present invention can effectively reduce or eliminate the problem of abnormal slapping noise of the decoupling diaphragm disc by setting the parameters of the vibration isolation structure and the specific component structure, and at the same time, it can provide a larger free design space for the design of the decoupling diaphragm disc, which is more conducive to the realization of hydraulic suspension performance.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile suspension, in particular to the field of vibration isolation structure of automobile hydraulic suspension. Background Art

[0002] Hydraulic mount is a commonly used suspension structure for today's automobiles. It can effectively improve the ride comfort of the vehicle. However, hydraulic mount has a variety of abnormal noise problems, which seriously affect the NVH performance experience of the vehicle. Among them, the abnormal noise caused by the decoupling membrane / disc hitting the upper and lower limit structures is the most important abnormal noise factor, such as Figure 1 As shown in the figure, the frequency range of abnormal noise caused by the decoupling membrane / disk hitting the upper and lower limiters is generally 200-600Hz. To address this problem, the existing improvement measures are: ① adjusting the decoupling membrane / disk morphology structure; ② removing the upper and lower limit structures, etc.; However, it is difficult to improve this problem through the above-mentioned improvement methods, and it usually leads to the deterioration of hydraulic suspension performance. This reliance on sacrificing the key performance of the hydraulic suspension to meet the NVH performance is a behavior of putting the cart before the horse. Summary of the invention

[0003] In order to solve the above problems, the present invention achieves the above objectives through the following technical solutions:

[0004] A vibration isolation structure for an automobile hydraulic suspension comprises a shell, wherein a first cavity is arranged in the shell, wherein a decoupling diaphragm disc module and a flow channel sleeved on the decoupling diaphragm disc module are arranged in the first cavity, wherein the outer wall of the flow channel is interference fit with the inner wall of the cavity; the decoupling diaphragm disc module comprises an exoskeleton, a decoupling diaphragm disc, an upper limit structure, a lower limit structure and a vibration-damping rubber; the exoskeleton consists of three parts: a side frame, an upper frame and a lower frame, and the three-part structure is combined to form a second cavity, the lower limit structure is arranged at the bottom of the second cavity, the upper frame is arranged at the top of the second cavity, and the decoupling diaphragm disc is arranged between the upper limit structure and the lower limit structure; the vibration-damping rubber is fixedly arranged between the lower limit structure and the side frame.

[0005] As a further optimization solution of the present invention, an inner side surface of the flow channel and an outer side surface of the side frame are interference fit.

[0006] As a further optimization scheme of the present invention, the upper limit structure is in an inverted U-shape, and a pin is provided at the center of its bottom surface protruding downward, a first through hole is provided at the center of the decoupling membrane disk, and the lower limit structure is U-shaped, and a second through hole is provided at the center; the pin passes through the first through hole and the second through hole in sequence.

[0007] As a further optimization solution of the present invention, the outer diameter of the upper limit structure is smaller than the outer diameter of the lower limit structure, and the upper limit structure is embedded in the lower limit structure.

[0008] As a further optimization scheme of the present invention, the natural frequency of the decoupling membrane disk module is less than the abnormal sound excitation frequency / 1.414, and the abnormal sound excitation frequency is the frequency of the decoupling membrane disk hitting the upper limit structure and the lower limit structure.

[0009] As a further optimization scheme of the present invention, when the abnormal sound excitation frequency range is 200-600 Hz, the natural frequency of the decoupling membrane disk module is 80 Hz.

[0010] The beneficial effects of the present invention are:

[0011] 1) The present invention can effectively reduce or eliminate the slapping noise problem of the decoupling diaphragm disc by setting the parameters of the vibration isolation structure and the specific component structure, and at the same time provide a larger free design space for the design of the decoupling diaphragm disc, which is more conducive to the realization of hydraulic suspension performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the frequency range of the abnormal noise of the suspension in the present invention;

[0013] Figure 2 It is an overall schematic diagram of the suspension vibration isolation structure of the present invention;

[0014] Figure 3 It is a schematic diagram of the shell structure in which the decoupling membrane disk module is removed in the present invention;

[0015] Figure 4 It is a schematic diagram of the decomposed structure of the decoupling membrane disk module in the present invention;

[0016] Figure 5 It is a three-dimensional schematic diagram of the decoupling membrane disk module without the upper frame in the present invention;

[0017] Figure 6 2 is a schematic diagram comparing the vibration isolation performance of the impact excitation force in the present invention;

[0018] In the figure: 1. Shell; 11. First cavity; 2. Decoupling membrane disc module; 21. External frame; 211. Side frame; 212. Upper frame; 213. Lower frame; 22. Decoupling membrane disc; 221. First through hole; 23. Upper limit structure; 231. Pin; 24. Lower limit structure; 241. Second through hole; 25. Vibration-damping rubber; 3. Flow channel; 4. Second cavity. DETAILED DESCRIPTION

[0019] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0020] like Figures 2 to 5 The vibration isolation structure of a hydraulic mount for an automobile shown in the figure comprises a housing 1, which serves as the structural basis of the entire hydraulic mount and is not only used to carry other components, but also used to press-fit the external components of the hydraulic mount; a liquid chamber, i.e., a first cavity 11, is provided in the housing 1, a decoupling membrane disc module 2 and a flow channel 3 are provided in the first cavity 11, and the flow channel 3 is sleeved on the decoupling membrane disc module 2;

[0021] Among them, the decoupling membrane disc module 2 includes an outer frame 21, a decoupling membrane disc 22, an upper limit structure 23, and a lower limit structure 24; the outer frame 21 includes a side frame 211, an upper frame 212, and a lower frame 213, and the side frame, the upper frame and the lower frame are combined to form a second cavity 4, and the decoupling membrane disc 22, the upper limit structure 23, and the lower limit structure 24 are arranged in the second cavity; the lower limit structure 24 is U-shaped and is arranged at the bottom of the second cavity 4; and the outer diameter of the upper limit structure 23 is smaller than the outer diameter of the lower limit structure 24, and the upper limit structure 23 is embedded in the lower limit structure 24, and a decoupling membrane disc 22 is arranged between the upper limit structure and the lower limit structure;

[0022] A pin 231 is protruding downward from the center of the bottom surface of the upper limit structure, a first through hole 221 is provided at the center of the decoupling membrane disc 22, and a second through hole 241 is provided at the center of the lower limit structure 24; the pin 231 passes through the first through hole 221 and the second through hole 241 in sequence;

[0023] The inner side surface of the flow channel 3 and the outer side surface of the side frame 211 are interference fit, and the outer side wall of the flow channel 3 and the inner side wall of the first cavity 11 are interference fit;

[0024] In addition, a vibration-damping rubber 25 is provided between the inner side surface of the side frame 211 and the side wall of the lower limiting structure 24; it should be noted that the vibration-damping rubber is not limited to the structural form shown in the drawings and can be adjusted according to specific performance requirements.

[0025] principle:

[0026] like Figure 1 As shown, under the conventional hydraulic suspension design, when the decoupling membrane / disc hits the upper and lower limits, the exciting force will be transmitted to the flow channel and the flow channel cover in a 1:1 manner, and then transmitted to the vehicle body through the bracket part of the hydraulic suspension. The exciting force has no obvious attenuation link in the whole transmission process, so it is very easy to cause abnormal noise problems;

[0027] In order to effectively reduce or eliminate the abnormal sound problem caused by the slapping of the decoupling diaphragm disk, the technical solution starts with the relationship between the natural frequency, stiffness and mass of the mechanical body, and improves the above-mentioned vibration isolation structure so that the natural frequency of the structure is lower than the excitation frequency (200-600Hz) within a certain range, such as the natural frequency <excitation frequency / 1.414, then effective vibration isolation can be formed for the abnormal sound excitation frequency; it should be noted that the abnormal sound excitation frequency referred to here is the frequency of the decoupling diaphragm disk 22 slapping the upper limit structure 23 and the lower limit structure 24;

[0028] In the above-mentioned vibration isolation structure, the structure of the decoupling membrane disk module 2 needs to be regarded as a single mass-spring system with its own specific natural frequency. According to the relationship between the natural frequency, stiffness and mass of the mechanical body, it can be known that the natural frequency of the decoupling membrane / disk module can be adjusted by adjusting the stiffness of the vibration-damping rubber, or adjusting the mass of the decoupling membrane disk 22, the upper limit structure 23 and the lower limit structure 24. In this way, the frequency of the decoupling membrane disk hitting the upper and lower limits can form an effective vibration isolation relationship with this natural frequency; that is, the natural frequency of the decoupling membrane disk module 2 is less than the abnormal sound excitation frequency / 1.414.

[0029] Furthermore, when the abnormal sound excitation frequency range is 200-600Hz, the natural frequency of the decoupling membrane disk module 2 can be set to 80Hz; of course, it can also be set to other values ​​as long as it meets the above conditions, which will form a good vibration isolation effect on the excitation force of the decoupling membrane / disk hitting the upper and lower limits; the specific analysis is as shown in the attached Figure 6 As shown:

[0030] It should be noted here that Figure 6 The straight line in the figure represents the traditional technical solution, and the curve represents the technical solution of this patent; and the natural frequency of the decoupling membrane disk module is set to 80Hz;

[0031] Taking the abnormal sound frequency of 200Hz as an example, the force transfer rate of the traditional design solution is 1, while the force transfer rate of the technical solution of this case is 0.2111; at the same time, taking the abnormal sound frequency of 600Hz as an example, the force transfer rate of the traditional design solution is 1, while the force transfer rate of the technical solution of this case is 0.0326; therefore, by adding Figure 4 It can be clearly seen from the data that the setting of the parameters of the vibration isolation structure and the specific component structure in the technical solution of this case can effectively reduce or eliminate the slapping noise problem of the decoupling diaphragm disc, and at the same time provide a larger free design space for the design of the decoupling diaphragm disc, which is more conducive to the realization of hydraulic suspension performance.

[0032] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A vibration isolation structure for a hydraulic mount of an automobile, characterized in that: The invention comprises a shell (1), wherein a first cavity (11) is provided in the shell (1), wherein a decoupling membrane disc module (2) and a flow channel (3) sleeved on the decoupling membrane disc module (2) are provided in the first cavity (11), wherein the outer wall of the flow channel (3) is interference-fitted with the inner wall of the first cavity (11); the decoupling membrane disc module (2) comprises an outer frame (21), a decoupling membrane disc (22), an upper limit structure (23), a lower limit structure (24), and a vibration-damping rubber (25); the outer frame (21) is composed of a side frame The second cavity (4) is composed of three parts: a frame (211), an upper frame (212) and a lower frame (213), and the three parts are combined to form a second cavity (4), the lower limit structure (24) is arranged at the bottom of the second cavity (4), the upper limit structure (23) is arranged at the top of the second cavity (4), and the decoupling membrane disk (22) is arranged between the upper limit structure (23) and the lower limit structure (24); the vibration-damping rubber (25) is fixedly arranged between the lower limit structure (24) and the side frame (211); An inner side surface of the flow channel (3) and an outer side surface of the side frame (211) are interference-fitted; The upper limit structure (23) is in an inverted U-shape, and a pin (231) is provided at the center of its bottom surface protruding downwards; a first through hole (221) is provided at the center of the decoupling membrane disc (22); the lower limit structure (24) is in a U-shape, and a second through hole (241) is provided at the center; the pin (231) passes through the first through hole (221) and the second through hole (241) in sequence; the outer edge of the decoupling membrane disc (22) protrudes upwards and downwards respectively to form a protruding portion; The outer diameter of the upper limit structure (23) is smaller than the outer diameter of the lower limit structure (24), and the upper limit structure (23) is embedded in the lower limit structure (24); The natural frequency of the decoupling membrane disc module (2) is less than the abnormal sound excitation frequency / 1.414, and the abnormal sound excitation frequency is the frequency of the decoupling membrane disc (22) hitting the upper limit structure (23) and the lower limit structure (24).

2. The vibration isolation structure of a vehicle hydraulic mount according to claim 1, characterized in that: When the abnormal sound excitation frequency range is 200-600 Hz, the natural frequency of the decoupling membrane disk module (2) is 80 Hz.

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