Seat vibration isolation structure and design method thereof

Abstract

The application relates to the field of seats, in particular to a seat vibration isolation structure and a design method thereof, which comprises an external framework, a rubber framework is arranged in the external framework; the external framework is connected with a seat, the rubber framework is connected with a vehicle body; the rubber framework is arranged protruding the external framework; the application avoids the rigid connection between a traditional seat and the vehicle body through the use of the external framework and the rubber framework; the comfort of seat riding is improved; meanwhile, the rubber framework has different vertical and lateral static stiffness, so that the vibration transmission attenuation can be guaranteed, the seat mounting point static stiffness can be guaranteed, the vertical excitation of the attenuation road, a power assembly and a suspension transmitted to the seat through the vehicle body can be guaranteed, and sufficient rigidity can be provided in the lateral direction to avoid the lateral vibration of the seat.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of seat, in particular to a seat vibration isolation structure and a design method thereof. BACKGROUND

[0002] The automobile seat plays a role of bearing the body of the driver and passenger, reducing the vibration caused by the bump of the automobile and alleviating the fatigue during the journey. The automobile seat is one of the most critical components affecting the comfort of the driver and passenger.

[0003] The automobile seat is rigidly connected to the floor of the vehicle body by bolts. When the vehicle is running, the excitation of the road, power assembly and suspension will be transmitted to the seat through the floor of the vehicle body, causing the vibration of the seat and affecting the driving experience.

[0004] The vibration reduction effect of the traditional seat is not good, and some high-end vibration reduction measures will bring expensive cost problems, which cannot be popularized in some low-end scooter models.

[0005] Some automobile seat buffer devices on the market, such as the adjustable automobile seat shock absorber disclosed in patent (CN201268250Y), include an upper bottom plate, a lower bottom plate and a support frame. The support frame is balanced between the upper and lower bottom plates by two groups of cross supports connected in the middle. A shock absorbing support arm is arranged in the middle of the two groups of cross supports.

[0006] The seat shock absorber can effectively absorb the vibration of the vehicle and improve the comfort. The overall structure of the seat is relatively complex, and the vibration transmitted from the vehicle body to the seat cannot be well reduced.

[0007] Therefore, in order to improve or solve at least one problem, the existing seat or seat connection structure needs to be optimized and designed. SUMMARY

[0008] The purpose of the present application is to provide a seat vibration isolation structure which can be used for the connection of the seat and the vehicle body and also has a vibration reduction effect.

[0009] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0010] A seat vibration isolation structure, comprising an external framework, wherein a rubber framework is arranged in the external framework; the external framework is connected to a seat, and the rubber framework is connected to a vehicle body; the rubber framework protrudes from the external framework.

[0011] The external framework is a metal framework.

[0012] The external framework comprises a framework sleeve, a fastening mechanism is arranged on the outer side of the framework sleeve, the fastening mechanism comprises a support seat, a seat fastening hole is arranged on the support seat; the rubber framework comprises a rubber main body, the rubber main body is inserted into the framework sleeve;

[0013] The rubber body is provided with a body fastening hole.

[0014] The rubber body is provided with a body fastening hole.

[0015] The fastening mechanism comprises a plurality of support seats, which are uniformly distributed on the outer side of the skeleton sleeve; each support seat is distributed in the middle region of the skeleton sleeve.

[0016] A design method of the seat vibration isolation structure, the design method comprising the following steps:

[0017] Step 1: decoupling the suspension and the seat frequency; the inherent frequency of the suspension and the inherent frequency of the seat are required to be different;

[0018] Step 2: when the seat is not installed with the seat vibration isolation structure, the actual vibration amplitude of the seat and the corresponding frequency are collected;

[0019] And the actual displacement of each seat mounting point of the seat in the vertical direction is obtained when the vehicle is running; and is recorded;

[0020] Step 3: under the actual displacement recorded in step 2, the vertical static stiffness required by the rubber skeleton is obtained;

[0021] Step 4: after step 3 is completed, the inherent frequency difference of the seat backrest when the seat vibration isolation structure is installed and when the seat vibration isolation structure is not installed is required to be not more than 1.0 Hz; and the lateral static stiffness of the rubber skeleton is obtained;

[0022] Step 5: based on the vertical static stiffness obtained in step 3 and the lateral static stiffness in step 4, a rubber skeleton and a seat vibration isolation structure meeting the requirements are designed.

[0023] In step 1, the inherent frequency of the suspension and the inherent frequency of the seat are required to be different by at least 4.0 Hz.

[0024] In step 3, the vibration attenuation amount after the vibration is transmitted by the seat vibration isolation structure is required to be not less than 20 dB.

[0025] In step 2, the position sensor is arranged at the seat mounting point to obtain the actual displacement of the seat mounting point in the vertical direction.

[0026] After the seat vibration isolation structure is designed, the seat vibration isolation structure is installed on the whole vehicle.

[0027] Then a vibration sensor is arranged on the nut of the connecting bolt when the rubber framework is connected with the vehicle body; another vibration sensor is arranged on the nut of the connecting bolt when the external framework is connected with the seat; then the vehicle is normally operated, and the vibration values collected by the two vibration sensors are compared; if the difference between the vibration values collected by the two vibration sensors is not less than 20dB; it represents that the vertical rigidity of the seat vibration isolation structure meets the requirements, otherwise, it represents that the vertical rigidity of the seat vibration isolation structure does not meet the requirements.

[0028] The present application has the advantages of:

[0029] The application discloses a seat vibration isolation structure and a design method thereof.

[0030] The present application avoids the rigid connection between the traditional seat and the vehicle body by using the external framework and the rubber framework, and increases the comfort of seat riding.

[0031] Meanwhile, the present application requires that the rubber framework has different vertical and lateral static rigidities, so that sufficient vibration transmission attenuation and seat mounting point static rigidity can be ensured, vertical excitation transmitted to the seat through the vehicle body from the road, power assembly and suspension can be attenuated, and sufficient rigidity in the lateral direction can be provided to avoid the lateral vibration of the seat. BRIEF DESCRIPTION OF DRAWINGS

[0032] The following is a brief description of the contents expressed by each drawing of the present application and the marks in the drawings:

[0033] Figure 1 It is a top view of the seat vibration isolation structure in the present application.

[0034] Figure 2 It is a sectional view of the seat vibration isolation structure in the present application.

[0035] Figure 3 It is a structure schematic view when the present application is connected with the vehicle body and the seat.

[0036] The marks in the above drawings are as follows:

[0037] 1, external framework, 2, support seat, 3, rubber framework, 4, vehicle body, 5, seat. DETAILED DESCRIPTION

[0038] The following is a further detailed description of the specific embodiments of the present application by comparing the drawings and describing the optimal embodiments.

[0039] A seat vibration isolation structure includes an outer frame 1, within which a rubber frame 3 is provided; the outer frame 1 is connected to a seat 5, and the rubber frame 3 is connected to a vehicle body 4; the rubber frame 3 protrudes from the outer frame 1; the present invention avoids the rigid connection between the traditional seat 5 and the vehicle body 4 by using the outer frame 1 and the rubber frame 3; thus increasing the comfort of the seat 5.

[0040] Meanwhile, this invention requires the rubber skeleton 3 to have sufficient vertical and lateral static stiffness differences, thereby ensuring sufficient vibration transmission attenuation while maintaining the static stiffness of the seat 5 mounting point. This ensures attenuation of the vertical excitation transmitted to the seat 5 from the road surface, powertrain, and suspension via the vehicle body 4, while also providing sufficient lateral rigidity to prevent lateral vibration of the seat 5.

[0041] The seat vibration isolation structure disclosed in this invention is mainly arranged at the connection position between the seat 5 and the vehicle body 4. In the traditional case, the seat 5 bracket is connected to the vehicle body 4. The basic function of the seat vibration isolation structure of this invention is to act as a connector. The seat 5 can be fixed to the vehicle body 4 through the seat vibration isolation structure. In this invention, the seat 5 generally has 4 mounting points with the vehicle body 4, so the seat 5 is generally connected to the vehicle body 4 through 4 seat vibration isolation structures.

[0042] In this invention, the seat vibration isolation structure mainly includes an outer frame 1, and a rubber frame 3 is provided inside the outer frame 1; the outer frame 1 is connected to the seat 5, and the rubber frame 3 is connected to the vehicle body 4; the rubber frame 3 is located inside the outer frame 1, the outer frame 1 ensures the structural strength of the seat vibration isolation structure, and the rubber frame 3 mainly plays the role of subsequent vibration isolation and damping.

[0043] In this invention, the outer skeleton 1 and the rubber skeleton 3 can be connected by a vulcanization process.

[0044] In this invention, the rubber skeleton 3 protrudes from the outer skeleton 1; based on this configuration, it is possible to avoid the outer skeleton 1 impacting the vehicle body 4 and causing abnormal noise during subsequent use.

[0045] In this invention, the external frame 1 is a metal frame; the metal frame can ensure the structural strength of the external frame 1, and steel sleeves or alloy sleeves can be selected, depending on the needs.

[0046] Furthermore, the external frame 1 in this invention includes a frame sleeve 11, which is mainly a cylindrical tube structure. In this invention, a fastening mechanism is provided on the outer side of the frame sleeve 11. The fastening mechanism facilitates the connection between the external frame 1 and the seat 5.

[0047] The fastening mechanism in the application comprises a support seat 2, which is provided with a seat fastening hole 21; the subsequent seat 5 is connected to the support seat 2 by bolts.

[0048] In the application, the rubber framework 3 comprises a rubber main body, which is inserted into the framework sleeve 11; the rubber main body is provided with a vehicle body fastening hole 31; in subsequent use, the rubber framework 3 is connected to the vehicle body 4 by bolts.

[0049] Meanwhile, in the application, the rubber main body protrudes from the framework sleeve 11 on the side close to the vehicle body 4; such arrangement can avoid the external framework 1 from impacting the vehicle body 4 and generating abnormal sound in subsequent use.

[0050] Further, in the application, the fastening mechanism comprises a plurality of support seats 2, which are evenly distributed on the outer side of the framework sleeve 11; based on the above design, the framework sleeve 11 and the seat 5 have a plurality of connection points, which can well ensure the stability of the connection between the seat 5 and the seat vibration isolation structure.

[0051] In addition, in the application, each support seat 2 is distributed in the middle area of the framework sleeve 11; such arrangement forms a stepped platform at the connection between the support seat 2 and the framework sleeve 11, so that the framework sleeve 11 can be inserted into the seat 5 in subsequent use, thereby better ensuring the stability and accuracy of the connection between the seat 5 and the seat vibration isolation structure.

[0052] A design method of the seat vibration isolation structure, which comprises the following steps:

[0053] Step 1: frequency decoupling of the suspension and the seat 5; the inherent frequency of the suspension is required to be different from the inherent frequency of the seat 5;

[0054] Step 2: when the seat 5 is not installed with the seat vibration isolation structure, the actual vibration amplitude and the corresponding frequency of the seat 5 are collected;

[0055] and the actual vertical displacement of each seat 5 mounting point of the seat 5 during vehicle operation is obtained; and recorded;

[0056] Step 3: the vertical static stiffness required by the rubber framework 3 is obtained under the actual displacement recorded in step 2;

[0057] Step 4: after step 3 is completed, the inherent frequency difference of the seat backrest of the seat 5 when installed with the seat vibration isolation structure and the inherent frequency of the seat backrest of the seat 5 when not installed with the seat vibration isolation structure is required to be not greater than 1.0 Hz; and the lateral static stiffness of the rubber framework 3 is obtained;

[0058] Step 5: the rubber framework 3 and the seat vibration isolation structure meeting the requirements are designed based on the vertical static stiffness obtained in step 3 and the lateral static stiffness in step 4.

[0059] Based on the above design, the seat vibration isolation structure design can be realized; and the seat vibration isolation structure meets the design requirements.

[0060] Further, in the present application, the suspension natural frequency and the seat 5 natural frequency deviation value is required to be at least 4.0Hz in step 1; based on such design requirements, the frequency decoupling of the suspension and the seat 5 can be realized, and the resonance vibration amplification of the suspension and the seat 5 is avoided; specifically, in the present application, the natural frequencies of the suspension and the seat 5 are identified, and the frequencies of the two are adjusted to be more than 4.0Hz by adjusting the structure of the seat 5.

[0061] Further, in the present application, the vibration attenuation amount is required to be not less than 20dB after the vibration is transmitted by the seat vibration isolation structure in step 3; based on such setting, the vibration isolation and buffering of the seat 5 can be better realized.

[0062] Further, in the present application, in step 2, the position sensor is arranged at the seat 5 mounting point to obtain the actual displacement corresponding to the vertical direction of the seat 5 mounting point; based on such setting, the actual displacement of each seat 5 mounting point under the actual working condition of the seat 5 is facilitated.

[0063] Further, in the present application, after the seat vibration isolation structure is designed, a vibration sensor is arranged on the nut of the connecting bolt when the rubber framework 3 and the vehicle body 4 are connected; another vibration sensor is arranged on the nut of the connecting bolt when the outer framework 1 and the seat 5 are connected; then the vehicle is normally operated, and the vibration values collected by the two vibration sensors are compared; if the difference between the vibration values collected by the two vibration sensors is not less than 20dB; it represents that the vertical stiffness of the seat vibration isolation structure meets the requirements, otherwise, it represents that the vertical stiffness of the seat vibration isolation structure does not meet the requirements; through the above operation arrangement, the vibration attenuation amount of the seat vibration isolation structure can be detected, which is used for detecting whether the vertical static stiffness of the rubber framework 3 meets the design requirements; and a good verification effect is achieved.

[0064] Specifically:

[0065] The application discloses a seat vibration isolation structure, which mainly comprises an outer framework 1, wherein the outer framework 1 is internally provided with a rubber framework 3; the outer framework 1 is connected with a seat 5; the rubber framework 3 is connected with a vehicle body 4; and the rubber framework 3 is arranged to protrude from the outer framework 1.

[0066] The seat vibration isolation structure is composed of metal and rubber, is installed between the seat 5 and the vehicle body 4, has different vertical and lateral (X, Y and Z three translational direction degrees of freedom under the whole vehicle coordinate system) static stiffnesses, and mainly plays a role in attenuating vibration transmission in the vertical direction and plays a role in guaranteeing the static stiffness of the seat 5 mounting point in the lateral direction.

[0067] The metal part of the seat vibration isolation structure is connected to the seat 5, and the rubber framework 3 is connected to the vehicle body 4, which reduces the vertical vibration transmitted from the vehicle body 4 to the seat 5, ensures the lateral mounting point static stiffness of the seat 5 mounting point, ensures that the seat 5 lateral mode is reduced by ≤1.0 Hz, and ensures that the seat 5 does not produce additional vibration.

[0068] Matching method: based on the excitation frequency and amplitude characteristics of the real vehicle dynamics, the control index is decomposed to the seat vibration isolation structure, and the problem is solved specifically, and the seat 5 vibration is effectively reduced.

[0069] Specifically, in the present application, the external framework 1 of the seat vibration isolation structure is a metal structure with a mounting point, the mounting point is connected to the seat 5 through a bolt, the mounting point is mainly a support seat 2, the rubber framework 3 is arranged in the external framework 1, the rubber framework 3 is connected with the external framework 1 through a vulcanization process, and a metal sleeve can be embedded in the middle of the rubber framework 3 and connected with the vehicle body 4 through a bolt.

[0070] Performance matching method of seat vibration isolation structure and seat 5:

[0071] 2.1 Frequency decoupling, identifying the natural frequency of the suspension and the seat 5, adjusting the seat 5 structure to avoid resonance and vibration amplification above 4.0 Hz;

[0072] 2.2 On the basis of 2.1, collect the amplitude and frequency characteristics of the actual vibration of the whole vehicle seat 5, obtain the actual displacement of the seat 5 at 54 mounting point positions under the driving condition of rough road at a speed of 50kph-120kph, and record it. (50kph-120kph belongs to common working condition, the seat 5 vibration is more obvious on rough road, other working conditions can be customized)

[0073] Adjust the rubber framework 3 and the static stiffness to meet the following requirements under different degrees of freedom:

[0074] (1) The vertical static stiffness is in the linear section within the displacement range collected in 2.2, and has a decay of ≥20.0 dB.

[0075] (2) The lateral static stiffness is not less than 2000N / mm, which ensures that the seat 5 backrest lateral mode is reduced by ≤1.0 Hz compared with 2.1.

[0076] 1. Based on 1.1 and 1.2, select appropriate mounting bolts according to the position and size of the seat 5 mounting bracket and the vehicle body 4 mounting point, realize the cooperation of the seat 5, the seat vibration isolation structure and the vehicle body 4;

[0077] 2. Modal frequency acquisition and decoupling requirements are proposed:

[0078] 2.1 Identify the inherent modal frequencies of the suspension system and the seat 5 under the whole vehicle boundary, the suspension modal is obtained by the conventional operating modal method, the operating condition is executed according to the requirements of 2.2; the seat 5 modal frequency measuring point is defined as the excitation point and the response point are both on the upper part of the seat 5 backrest (close to the shoulder position of the occupant), and the test method adopts the conventional hammer modal test method. Record the first vertical inherent frequency of the suspension and the first modal frequency of the seat 5 X and Y directions (using the whole vehicle coordinate system).

[0079] 2.2 Define the first lateral modal of the seat 5 to be higher than the suspension modal by ≥4.0Hz; define the frequency difference between the X and Y directions of the seat 5 to be ≥2Hz to avoid resonance amplification caused by coupling of the suspension and the seat 5 modal. If it is found that it does not meet the requirements, the seat 5 modal can be adjusted by strengthening or weakening the external framework 1 of the seat 5.

[0080] 3. Determine the static stiffness of the rubber framework 3 in different degrees of freedom.

[0081] 3.1 The static stiffness determination method of the rubber framework 3 in the vertical direction (the Z direction of the whole vehicle coordinate system):

[0082] The vibration of the tire, the suspension and the power assembly is mainly transmitted to the seat 5 through the floor of the vehicle body 4 in the normal direction (i.e. the vertical direction), therefore, the vertical vibration excitation is the most important excitation accepted by the seat 5, and the vibration isolation effect of the rubber framework 3 is best in this direction, and therefore the definition method of the vertical static stiffness of the rubber is as follows:

[0083] 3.1.1 Obtain the vertical displacement of the seat 5 mounting point: on the basis of meeting the decoupling requirements in 2.1, arrange displacement sensors at the four mounting points of the seat 5, test the working condition according to 2.1 in the content part, obtain the actual displacement of the seat 5 four mounting points in the vertical direction under the condition that the vehicle is driven at a speed of 50kph-120kph on a rough road, and record the interval from the maximum displacement to the minimum displacement.

[0084] 3.1.2 Under the displacement condition recorded in 3.1.1, the vertical static stiffness of the rubber framework 3 is required to be in the linear segment, and the vibration attenuation amount of the main and passive sides of the rubber framework 3 is required to be ≥20dB, and the evaluation method is to arrange vibration sensors on the main and passive sides respectively, and the vehicle is operated according to the working condition in 3.1.1, and the vibration values are collected for comparison. The definitions of the main and passive sides are shown in the following figure: the nut of the bolt connecting the rubber framework 3 and the vehicle body 4 is defined as the active side; the nut of the bolt connecting the seat 5 and the external framework 1 of the seat vibration isolation structure is defined as the passive side.

[0085] 3.1.3 Record the structure and static stiffness of the rubber that meets the condition of 3.1.2.

[0086] 3.2 The static stiffness definition method of the rubber framework 3 in the lateral direction (the X and Y horizontal translation direction degrees of freedom of the whole vehicle coordinate system):

[0087] The seat 5 backrest is a cantilever beam structure, and the backrest is more prone to shaking in the lateral direction, therefore, in addition to ensuring the requirements in 3.1.2, the seat 5 backrest mode is required to be as high as possible, which is more conducive to inhibiting shaking.

[0088] The static stiffness of the seat 5 mounting point is positively correlated with the seat 5 backrest mode, therefore, the rubber framework 3 is adjusted and matched, so that the lateral static stiffness is not less than 2000 N / mm, and the seat 5 backrest lateral mode is reduced by not more than 1.0 Hz compared with that collected in 2.1, and the rubber lateral static stiffness meeting the requirements is recorded.

[0089] 3.3 The rubber seat vibration isolation structure meeting the static stiffness and vibration isolation requirements in three degrees of freedom directions in 2.1 and 2.2 is recorded, that is, the physical structure required by the application, wherein the static stiffness, mode frequency and vibration isolation implementation process are the matching method described in the application.

[0090] Obviously, the specific implementation of the application is not limited by the above-mentioned manner, and various non-essential improvements using the method concept and technical solution of the application are within the protection scope of the application.

Claims

1. A design method of a seat vibration isolation structure, characterized by, The seat vibration isolation structure comprises an outer framework, a rubber framework arranged in the outer framework, the outer framework being connected with the seat, the rubber framework being connected with the vehicle body, and the rubber framework protruding from the outer framework; The design method comprises the following steps: Step 1: frequency decoupling of the suspension and the seat is performed, and the inherent frequency of the suspension is required to be different from the inherent frequency of the seat; Step 2: when the seat is not installed with the seat vibration isolation structure, the actual vibration amplitude of the seat and the corresponding frequency are collected, and the actual vertical displacement of each seat mounting point of the seat during vehicle operation is obtained and recorded; Step 3: the vertical static stiffness required by the rubber framework is obtained under the actual displacement recorded in step 2; Step 4: after step 3 is completed, the inherent frequency difference of the seat backrest when the seat vibration isolation structure is installed and when the seat vibration isolation structure is not installed is required to be not more than 1.0 Hz, and then the lateral static stiffness of the rubber framework is obtained; Step 5: the rubber framework and the seat vibration isolation structure meeting the requirements are designed based on the vertical static stiffness obtained in step 3 and the lateral static stiffness in step 4. The outer framework is a metal framework.

2. The design method of a seat vibration isolation structure according to claim 1, wherein The outer framework comprises a framework sleeve, a fastening mechanism is arranged on the outer side surface of the framework sleeve, the fastening mechanism comprises a support seat, a seat fastening hole is arranged on the support seat, the rubber framework comprises a rubber main body, and the rubber main body is inserted into the framework sleeve.

3. The design method of a seat vibration isolation structure according to claim 1, wherein A vehicle body fastening hole is arranged on the rubber main body. The rubber main body is arranged to protrude from the framework sleeve on the side close to the vehicle body.

4. The design method of a seat vibration isolation structure according to claim 3, wherein The fastening mechanism comprises a plurality of support seats, the plurality of support seats are uniformly distributed at intervals on the outer side of the framework sleeve, and each support seat is arranged in the middle region of the framework sleeve.

5. The design method of a seat vibration isolation structure according to claim 3, wherein In step 1, the inherent frequency of the suspension is required to be different from the inherent frequency of the seat by at least 4.0 Hz.

6. The method of designing a seat vibration isolation structure according to claim 1, wherein In step 3, the vibration attenuation amount after the vibration is transmitted by the seat vibration isolation structure is required to be not less than 20 dB.

7. The method of designing a seat vibration isolation structure according to claim 1, wherein In step 2, a position sensor is arranged at the seat mounting point to obtain the actual vertical displacement of the corresponding seat mounting point.

8. The method of designing a seat vibration isolation structure according to claim 1, wherein After the seat vibration isolation structure is designed, the seat vibration isolation structure is installed on the whole vehicle; 9. The design method of a seat vibration isolation structure according to claim 8, wherein Then, a vibration sensor is arranged on the nut of the connecting bolt when the rubber framework is connected with the vehicle body, and another vibration sensor is arranged on the nut of the connecting bolt when the outer framework is connected with the seat, then the vehicle is normally operated, the vibration values collected by the two vibration sensors are compared, if the vibration value difference collected by the two vibration sensors is not less than 20 dB, it is indicated that the vertical stiffness of the seat vibration isolation structure meets the requirements, otherwise, it is indicated that the vertical stiffness of the seat vibration isolation structure does not meet the requirements. ​

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