A gearbox mounting system with adaptive stiffness

Abstract

A gearbox suspension system with adaptive stiffness regulation comprises an upper support and a lower support, the bottom of the upper support is respectively provided with a rubber main spring rubber body and a rubber auxiliary spring rubber body, and the upper support is directly fixedly connected with the lower support through the rubber main spring rubber body in a normal state, and the rubber auxiliary spring rubber body is suspended in the lower support, the main body of the lower support is cylindrical, a cylindrical rubber main spring inner framework is arranged in the lower support, one end of the rubber main spring inner framework is sleeved with the rubber main spring rubber body supported in the lower support, the other end of the rubber main spring inner framework is sleeved with the rubber auxiliary spring rubber body with a smaller diameter than the rubber main spring rubber body, the rubber auxiliary spring inner framework is supported in the rubber auxiliary spring rubber body, the lower ends of the side plates are fixedly connected through bolts and nuts, and the bolts of the bolts and nuts penetrate the rubber main spring inner framework. The present application can sense the running state of the vehicle and the road condition in real time, and automatically adjust the suspension stiffness quickly to adapt to the requirements under different working conditions.

Description

Technical Field

[0001] This invention belongs to the technical field of automotive powertrain mounting systems, specifically a transmission mounting system with adaptive stiffness adjustment. Background Technology

[0002] The transmission mount is a key component of the automotive powertrain mounting system. Its main functions are to support the weight of the transmission, limit its displacement, and dampen the transmission of vibrations generated by the transmission to the vehicle body, thereby improving the smoothness and comfort of the ride. Under low-frequency conditions (such as rapid acceleration, rapid deceleration, deep potholes, and rough roads), the transmission mount requires greater stiffness and damping to limit excessive transmission displacement. Under high-frequency conditions (such as idling), it requires lower stiffness to reduce vibration transmission.

[0003] Currently, most transmission mounts in the industry use rubber mounts. These rubber mounts typically consist of two metal plates with vulcanized rubber in between. While simple and low-cost, they lack effective limiting mechanisms and struggle to simultaneously meet vibration isolation requirements for both low-frequency, high-amplitude and high-frequency, low-amplitude vibrations. Over-constraint in the transmission mounts causes an increase in the modal frequencies of the powertrain in all six directions, worsening the decoupling rate in each direction. Typically, adding a rubber-mounted transmission mount while keeping the front and rear engine mounts unchanged results in an increase in the powertrain's rigid body modal frequency around the X-axis from approximately 15Hz to around 19Hz, with a decrease in the decoupling rate in all six directions of about 20%. As the rigid body modal frequency of the powertrain increases, the mounts shift from the vibration isolation zone to the resonance zone, significantly reducing the vibration isolation rate of the mount system and consequently, significantly decreasing the overall vehicle comfort. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a gearbox mounting system with adaptive stiffness adjustment, which can adaptively adjust stiffness according to vibration conditions, has a simple structure, and is cost-effective.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: an adaptive stiffness-adjustable gearbox mounting system, comprising an upper bracket and a lower bracket, wherein a rubber main spring body and a rubber auxiliary spring body are respectively provided at the bottom of the upper bracket, and in normal condition the upper bracket is directly fixedly connected to the lower bracket through the rubber main spring body, while the rubber auxiliary spring body is suspended in the lower bracket.

[0006] Furthermore, the main body of the lower support is cylindrical, and the lower part is provided with a U-shaped lower base. The cylindrical rubber main spring inner skeleton is set inside the lower support. One end of the rubber main spring inner skeleton is fitted with a rubber main spring body supported in the lower support, and the other end of the rubber main spring inner skeleton is fitted with a rubber auxiliary spring body with a diameter smaller than that of the rubber main spring body. The rubber auxiliary spring body is internally supported by the rubber auxiliary spring inner skeleton. The front and rear of the upper support are respectively supported by downwardly extending side plates. The lower ends of the side plates are fixedly connected by bolts and nuts, and the bolts of the bolts and nuts penetrate through the rubber main spring inner skeleton.

[0007] Furthermore, a rubber main spring outer sleeve is provided on the inner wall of the lower support.

[0008] Furthermore, the main body of the rubber spring is circular, with both the front and rear ends concave inward, and the main body of the rubber spring has multiple through holes penetrating its body.

[0009] Furthermore, the upper support has a U-shaped cross-section, and bolt holes are passed through both ends of the upper and lower supports.

[0010] Furthermore, a radial limiting rubber layer for the rubber main spring is provided on the inner wall of the outer sleeve of the rubber main spring.

[0011] Furthermore, the inner frame of the rubber auxiliary spring is fixed to the inner frame of the rubber main spring by screwing on the connecting thread.

[0012] Furthermore, the inner arc structure along the upper edge of the middle part of the lower base is attached to and fixedly connected to the outer side of the main body of the lower support.

[0013] With the above settings, a first gap is reserved between the rubber body of the rubber auxiliary spring and the radial limiting rubber layer of the rubber main spring. When the vibration amplitude is small (such as idling, the amplitude is approximately 0.5-1.5mm), the rubber main spring works alone, effectively isolating vibration by utilizing its low stiffness characteristics. When the vibration amplitude increases (such as rapid acceleration, rapid deceleration, deep potholes, bad roads, and other severe conditions, the amplitude can reach 5-10mm), the rubber body of the rubber auxiliary spring contacts the radial limiting rubber layer of the rubber main spring, and the rubber auxiliary spring intervenes to work, using the higher stiffness of the rubber auxiliary spring to limit excessive displacement of the gearbox.

[0014] This invention can sense the vehicle's operating status and road conditions in real time and quickly and automatically adjust the suspension stiffness to adapt to the needs of different working conditions.

[0015] The present invention has the following beneficial effects: 1. Adaptive adjustment characteristics: Through the coordinated work of the rubber auxiliary spring and the rubber main spring, it automatically adapts to low-frequency large amplitude and high-frequency small amplitude working conditions, and also has the functions of dynamic isolation and displacement limitation. 2. Impact of system matching calculation: The frequency impact of the rigid body modes of the powertrain in six directions is ≤1Hz, and the average impact of the decoupling rate in six directions is ≤5%; 3. Improve overall vehicle NVH performance: NVH performance is improved by more than 20%, and the cabin noise is reduced by about 3 decibels, which can effectively improve the driving environment; 4. Structural optimization: Compared with hydraulic suspension, the complex fluid channels and seals are eliminated, reducing manufacturing difficulty and cost, while improving reliability. Attached Figure Description

[0016] The present invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the present invention without the upper support; Figure 3 This is a three-dimensional structural diagram of the other side of the present invention with the upper support removed; Figure 4 This is a schematic diagram of the cross-sectional structure of the present invention. Detailed Implementation

[0018] like Figure 1-4 As shown, an adaptive stiffness-adjustable gearbox mounting system includes an upper bracket 1 and a lower bracket 2. The bottom of the upper bracket 1 is respectively provided with a rubber main spring rubber body 5 and a rubber auxiliary spring rubber body 6. Under normal conditions, the upper bracket 1 is directly fixedly connected to the lower bracket 2 through the rubber main spring rubber body 5, while the rubber auxiliary spring rubber body 6 is suspended in the lower bracket 2, that is, the rubber auxiliary spring rubber body 6 does not contact the lower bracket 2 at this time.

[0019] Specifically: The main body of the lower support 2 is cylindrical, and the lower part is provided with a U-shaped lower base 3. The cylindrical rubber main spring inner frame 4 is set inside the lower support 2. One end of the rubber main spring inner frame 4 is fitted with a rubber main spring body 5 supported inside the lower support 2. The other end of the rubber main spring inner frame 4 is fitted with a rubber auxiliary spring body 6 with a diameter smaller than that of the rubber main spring body 5. In this way, the rubber auxiliary spring body 6 does not contact the lower support 2. The rubber auxiliary spring body 6 is internally supported by the rubber auxiliary spring inner frame 7. The front and rear of the upper support 1 are respectively supported by downwardly extending side plates 8. The lower ends of the side plates 8 are fixedly connected by bolts and nuts 9, and the bolts of the bolts and nuts 9 penetrate through the rubber main spring inner frame 4.

[0020] The inner wall of the lower support 2 is provided with a rubber main spring outer sleeve 10, and the inner wall of the rubber main spring outer sleeve 10 is provided with a rubber main spring radial limiting rubber layer 13. The main body of the rubber main spring rubber body 5 is circular, and the front and rear end faces are both concave inward. The main body of the rubber main spring rubber body 5 is provided with multiple through holes 11 penetrating its main body. The upper support 1 has a U-shaped cross section, and bolt holes 12 are respectively passed through both ends of the upper support 1 and the lower support 2. The rubber auxiliary spring inner frame 7 is screwed and fixed to the rubber main spring inner frame 4 by connecting thread 14. The upper edge of the middle part of the lower base 3 is attached to and fixedly connected to the outer side of the main body of the lower support 2.

[0021] Working principle of this invention: The upper bracket 1 is formed by sheet metal stamping and has bolt holes 12 at both ends for fixing to the longitudinal beam of the vehicle body by bolts. The lower bracket 2 is formed by sheet metal stamping and has bolt holes 12 at both ends for fixing to the gearbox by bolts. The rubber body 5 of the rubber main spring is made of nitrile rubber (NBR) or natural rubber (NR), with a Shore hardness of 40-65HA. It is fixedly connected to the inner wall of the rubber main spring outer sleeve 10 and the outer wall of the rubber main spring inner skeleton 4 through a vulcanization process to form an integral load-bearing structure. The rubber main spring outer sleeve 10 needs to be reduced in diameter. The reduction is usually 5%-10% of the rubber thickness and less than 5% of the outer sleeve diameter. The rubber body 5 of the rubber main spring and the lower support 2 are fixedly connected by an interference fit. The rubber body 6 of the auxiliary spring is made of polyurethane elastomer or natural rubber (NR) with a Shore hardness of 60-80HA. A first gap is reserved between the rubber body 6 and the radial limiting rubber layer 13 of the main spring. The first gap is usually set to 2.5mm-5mm (in this example, the first gap is usually set to 3mm). When the vibration amplitude of the gearbox is less than the first limiting gap, the rubber body 5 of the main spring bears the vibration load alone. When the vibration amplitude is greater than or equal to the first limiting gap, the radial limiting rubber layer 13 of the main spring contacts the rubber body 6, and the rubber body 5 of the main spring... Together with the rubber body 6 of the rubber auxiliary spring, they bear the load, thus forming an auxiliary load-bearing structure. The contact area increases with the increase of the vibration amplitude. That is, when the vibration amplitude is small (such as idling, the amplitude is about 0.5-1.5mm), the rubber main spring works alone and effectively isolates the vibration by utilizing its low stiffness characteristics. When the vibration amplitude increases (such as rapid acceleration, rapid deceleration, deep potholes, bad roads and other severe conditions, the amplitude can reach 5-10mm), the rubber body 6 of the rubber auxiliary spring contacts the radial limiting rubber layer of the rubber body 5 of the rubber main spring, and the rubber auxiliary spring intervenes to work, using the higher stiffness of the rubber auxiliary spring to limit the excessive displacement of the gearbox.

[0022] The transmission mount with this adaptive stiffness adjustment was compared and verified with the old structure transmission mount in the same vehicle model: I. Parameter Input: 1. Powertrain weight parameters

[0023] 2. Suspension position

[0024] 3. Suspension installation angle

[0025] 4. Stiffness (N / mm) of suspension in its local coordinate system (ui, vi, wi)

[0026] II. Output of Calculation Results: 1. Calculation results of suspension decoupling (without gearbox suspension)

[0027] 2. Decoupling calculation results for the old structure gearbox mounting

[0028] 3. Decoupling calculation results of gearbox mount with adaptive stiffness adjustment

[0029] 4. Comparison of matching calculation results 1) Analysis and calculation show that the influence of the rigid body modes of the new structure gearbox mounting powertrain in six directions is ≤1Hz, and the average influence of the decoupling rate in six directions is ≤5%. 2) With the front and rear engine mounts remaining unchanged, only the old structure transmission mount was added, which caused the powertrain rigid body mode frequency around the X-axis to increase from 14.8Hz to 19.1Hz, an increase of 4.3Hz; the decoupling rate in six directions decreased by an average of 33.3%.

[0030] III. Vehicle NVH Testing: 1. Test results of vibration isolation rate of the old structure gearbox mounting

[0031] 2. Test results of vibration isolation rate of gearbox mount with adaptive stiffness adjustment

[0032] 3. NVH test results for the cab

[0033] 4. Comparison of NVH test results for the whole vehicle: The transmission mount with adaptive stiffness adjustment has a 14% higher vibration isolation rate, a 25% lower cab vibration, and a 3.5 decibel reduction in cab noise compared to the old structure transmission mount.

[0034] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A gearbox mounting system with adaptive stiffness adjustment, comprising an upper bracket (1) and a lower bracket (2), characterized in that: The bottom of the upper bracket (1) is provided with a rubber main spring rubber body (5) and a rubber secondary spring rubber body (6). Under normal conditions, the upper bracket (1) is directly fixedly connected to the lower bracket (2) through the rubber main spring rubber body (5), while the rubber secondary spring rubber body (6) is suspended in the lower bracket (2).

2. The gearbox mounting system with adaptive stiffness adjustment as described in claim 1, characterized in that: The main body of the lower support (2) is cylindrical, and the lower part is provided with a U-shaped lower base (3). The cylindrical rubber main spring inner frame (4) is set inside the lower support (2). One end of the rubber main spring inner frame (4) is fitted with a rubber main spring rubber body (5) supported inside the lower support (2). The other end of the rubber main spring inner frame (4) is fitted with a rubber secondary spring rubber body (6) with a diameter smaller than that of the rubber main spring rubber body (5). The rubber secondary spring rubber body (6) is supported by the rubber secondary spring inner frame (7). The front and rear of the upper support (1) are respectively supported by downwardly extending side plates (8). The lower ends of the side plates (8) are fixedly connected by bolts and nuts (9), and the bolts of the bolts and nuts (9) penetrate through the rubber main spring inner frame (4).

3. The gearbox mounting system with adaptive stiffness adjustment as described in claim 2, characterized in that: The inner wall of the lower support (2) is provided with a rubber main spring outer sleeve (10).

4. The gearbox mounting system with adaptive stiffness adjustment as described in claim 2, characterized in that: The main body of the rubber spring (5) is circular, and both the front and rear ends are concave inward. The main body of the rubber spring (5) is provided with multiple through holes (11) that penetrate its main body.

5. The adaptive stiffness adjustment gearbox mounting system as described in claim 2, characterized in that: The upper support (1) has a U-shaped cross section, and bolt holes (12) are passed through both ends of the upper support (1) and the lower support (2).

6. The gearbox mounting system with adaptive stiffness adjustment as described in claim 2, characterized in that: The inner wall of the rubber main spring outer sleeve (10) is provided with a rubber main spring radial limiting rubber layer (13).

7. The gearbox mounting system with adaptive stiffness adjustment as described in claim 2, characterized in that: The inner frame (7) of the rubber secondary spring is screwed onto the inner frame (4) of the rubber main spring by connecting thread (14).

8. The gearbox mounting system with adaptive stiffness adjustment as described in claim 2, characterized in that: The upper edge of the middle part of the lower base (3) is connected to the outer side of the main body of the lower bracket (2) by the inner arc structure.

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