A balanced suspension system

Abstract

This application discloses a balanced suspension system, relating to the field of automotive suspension system technology. It includes: a leaf spring assembly comprising a main leaf spring structure and a secondary leaf spring structure. The main leaf spring structure includes a leaf spring body, which is a single-leaf spring structure made of composite material. Both ends of the main leaf spring structure are slidably inserted into leaf spring connecting seats on the top surface of a first rear axle and a second rear axle. The secondary leaf spring structure includes a first airbag and a second airbag, both airbags being vertically oriented and distributed on both sides of a cover plate. The top end of each airbag is fixed relative to the vehicle frame, and the bottom end is mounted on the upper surface of the leaf spring body. This balanced suspension system meets lightweight requirements while improving roll stiffness and full-load reliability without affecting unloaded ride comfort.

Description

Technical Field

[0001] This application relates to the field of automotive suspension system technology, specifically to a balanced suspension system. Background Technology

[0002] Currently, the vehicle's balance suspension is a key and major assembly in the vehicle chassis. It bears the entire load and transmits it to the axle, enabling the drive wheels to travel under any road conditions. The balance suspension system is responsible for carrying tens of tons of cargo. It is the main load-bearing component besides the chassis and plays a very important role in heavy-duty vehicles.

[0003] In related technologies, existing vehicle models with dual rear axles and balanced suspension configurations have rear leaf spring assemblies 1 made of multi-layer high-quality alloy steel, which have high strength and rigidity. The middle part of the rear leaf spring assembly 1 is fixed to the balance shaft bracket 3 through a cover plate 2 and U-bolts 4, and the end of the rear leaf spring assembly 1 slides in contact with the first sliding plate 5 and the second sliding plate 6 on the axle.

[0004] However, the existing rear leaf spring assembly 1 is made of spring steel, which has a high density and is heavy. It is impossible to reduce the weight of the leaf spring while ensuring its performance, thus failing to meet the requirements for vehicle lightweighting. Its weight ratio is too high, reaching about 6%, which cannot meet the needs of product upgrades. At the same time, the traditional balance suspension does not monitor the rear leaf spring assembly 1 under full load, and its reliability needs to be improved. In addition, although the rear leaf spring assembly 1 itself has high stiffness, its stiffness has little effect when measuring roll stiffness. Those skilled in the art have considered adding a rigid structure to enhance reliability and roll stiffness, but this would affect the ride comfort under no-load conditions, so it cannot be implemented.

[0005] Therefore, those skilled in the art urgently need to design a balanced suspension that meets the requirements of lightweighting, roll stiffness and full-load reliability, but does not affect the ride comfort under no-load conditions. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this application is to provide a balanced suspension system that not only meets the requirements of lightweighting, but also improves roll stiffness and full-load reliability without affecting the ride comfort under no-load conditions.

[0007] To achieve the above objectives, the technical solution adopted is: a balanced suspension system, the balanced suspension system including a leaf spring assembly, the leaf spring assembly including a main spring structure and a secondary spring structure, the main spring structure including a leaf spring body, the leaf spring body being a single-leaf spring structure made of composite material; the two ends of the main spring structure can be slidably inserted into the leaf spring connecting seats on the top surface of the first rear axle and the leaf spring connecting seats on the top surface of the second rear axle respectively; the secondary spring structure includes a first airbag and a second airbag, both airbags are vertically arranged and distributed on both sides of the cover plate, the top end of each airbag is relatively fixed to the vehicle frame, and the bottom end is installed on the upper surface of the leaf spring body.

[0008] Based on the above technical solution, both the first airbag and the second airbag have a limiting block structure installed from top to bottom inside, and the top of the limiting block structure is fixed to the vehicle frame.

[0009] Based on the above technical solution, the leaf spring connecting seat on the top surface of the first rear axle includes a first sliding plate and a first guide seat, and one end of the main spring structure can be slidably inserted between the first sliding plate and the first guide seat; the leaf spring connecting seat on the top surface of the second rear axle includes a second sliding plate and a second guide seat, and the other end of the main spring structure can be slidably inserted between the second sliding plate and the second guide seat.

[0010] Based on the above technical solution, the composite material of the leaf spring body adopts fiber-reinforced material and thermosetting resin. The fiber-reinforced material adopts one or more of E-glass fiber, aramid fiber or basalt fiber, and the thermosetting resin adopts epoxy resin or PDCPD resin. The density of the leaf spring body is 1.8~2.2g / cm^3. The main leaf spring structure also includes a first reinforcing component and a second reinforcing component. The first reinforcing component is divided into upper and lower U-shaped plates, and the upper and lower U-shaped plates surround the middle section of the leaf spring body. The second reinforcing component is divided into a channel steel structure and a flat plate structure, and the channel steel structure and the flat plate structure surround and fix to the end of the leaf spring body.

[0011] Based on the above technical solution, the auxiliary spring structure further includes a first mounting seat and a second mounting seat, both of which are fixed to the vehicle frame; the top end of the first airbag is fixed to the first mounting seat, and the bottom end is fixed to the center of one half of the leaf spring body; the top end of the second airbag is fixed to the second mounting seat, and the bottom end is fixed to the center of the other half of the leaf spring body.

[0012] Based on the above technical solution, the balance suspension system further includes a main solenoid valve, a first solenoid valve, and a second solenoid valve. The input end of the main solenoid valve is connected to the vehicle's air supply component via a pipeline, and the output end of the main solenoid valve is split into two paths: one path is connected to the first airbag via the first solenoid valve, and the other path is connected to the second airbag via the second solenoid valve. The main solenoid valve is used to control the air pressure output by the vehicle's air supply component, the first solenoid valve is used to control the air pressure input to the first airbag, and the second solenoid valve is used to control the air pressure input to the second airbag.

[0013] Based on the above technical solution, the first airbag is equipped with a first air pressure sensor, and the second airbag is equipped with a second air pressure sensor. Both the first and second air pressure sensors are connected to the ECU in the driver's cab. The first and second air pressure sensors monitor the airbag pressure in real time and feed the pressure value back to the ECU in the driver's cab.

[0014] Based on the above technical solution, the balance suspension system also includes a cab knob k1, a cab knob k2, and a cab knob k3 installed in the cab; the cab knob k1 controls the output air pressure of the main solenoid valve, the cab knob k2 controls the output air pressure of the first solenoid valve, and the cab knob k3 controls the output air pressure of the second solenoid valve.

[0015] Based on the above technical solution, the cab knob k1 includes at least three positions, namely the zero air pressure position corresponding to the vehicle being unloaded, the set air pressure position corresponding to the vehicle being fully loaded, and the maximum air pressure position equivalent to the air pressure inside the vehicle's air source components; the cab knob k2 and the cab knob k3 include at least two positions, namely the neutral position and the full position.

[0016] Based on the above technical solution, the cab ECU is used to calibrate and convert the air pressure value obtained from the first air pressure sensor into the axle load information of the first rear axle, and is also used to calibrate and convert the air pressure value obtained from the second air pressure sensor into the axle load information of the second rear axle, and then sum the two axle load information and display it on the instrument panel; when the sum of the two axle load information exceeds the set range, the cab ECU will issue an alarm.

[0017] The beneficial effects of the technical solution provided in this application include:

[0018] 1. The balance suspension system of this application adopts a combination structure of main spring structure and auxiliary spring structure. Compared with the traditional balance suspension, the leaf spring body is a single-leaf spring structure made of composite material, which greatly reduces the weight while ensuring stiffness and strength, and realizes the lightweighting of the whole vehicle. At the same time, the auxiliary spring structure added to the balance suspension system includes a first airbag and a second airbag, which can flexibly adjust the air pressure. It does not affect the smoothness under no-load conditions. Under full load or harsh working conditions, the first airbag and the second airbag inflate as needed to bear the load, which can greatly improve reliability and roll stability, thereby improving the service life and comfort of the vehicle and increasing the value for customers.

[0019] 2. Both the first and second airbags of this application are equipped with limiting block structures. These limiting block structures are vertically arranged from top to bottom, with their top ends fixed relative to the vehicle frame. The limiting block structures do not affect the contraction and expansion of the airbags. During the operation of the first and second airbags, the bottom surface of the limiting block structure is normally detached from the upper surface of the leaf spring body. When the rear axle jumps to its extreme position, the limiting block structure abuts against the leaf spring body. This application's balanced suspension system cleverly incorporates limiting block structures inside both the first and second airbags, further enhancing the reliability of the suspension system.

[0020] 3. The balance suspension system of this application uses the above-mentioned composite material, which can reduce the weight of the leaf spring body. Specifically, the existing leaf spring body accounts for about % of the total vehicle weight, while the one of this application accounts for about % of the total vehicle weight, meeting the needs of vehicle product upgrades; it can also ensure the performance of the leaf spring body, and can perfectly replace the existing multi-layer alloy steel leaf spring body. The leaf spring body has been verified by a large number of tests to meet various performance requirements such as stiffness and strength.

[0021] 4. The balance suspension system of this application uses the output air pressure of the main solenoid valve through the cab knob k to control the output air pressure of the first solenoid valve and the output air pressure of the second solenoid valve, so as to flexibly adjust the output air pressure to adapt to different driving conditions, and improve the full-load reliability and roll stability without affecting the ride comfort.

[0022] 5. In the balanced suspension system of this application, the cab ECU calibrates and converts the rear axle load information by looking up a table based on the two received air pressure values, and displays the sum of the two rear axle load information on the instrument panel; when the sum of the two rear axle load information exceeds the set range, the cab ECU alarms, which can indirectly determine whether the composite leaf spring body has failed through the rear axle load, and make predictions in advance, further enhancing reliability.

[0023] 6. The leaf spring assembly composed of the main spring structure and the auxiliary spring structure of this application has increased stiffness compared with the traditional rear leaf spring assembly, which can increase the roll angle stiffness of the balance suspension system, thereby improving the roll stability of the vehicle under harsh conditions such as overload, bad roads, and mountain curves. From the comparison curve of roll load and displacement, it can be clearly seen that after the air spring plays a load-bearing role, under the same load, the displacement of the balance suspension system of this application is smaller, and a larger load is required to reach the limit displacement. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a prior art balance suspension system;

[0026] Figure 2 This is a schematic diagram of the balance suspension system of this application;

[0027] Figure 3 Displacement-load curves of the balance suspension system of this application and the balance suspension system of the prior art during roll;

[0028] Figure 4 This is a schematic diagram of the air pressure flow direction and control components of the balance suspension system of this application.

[0029] Reference numerals: 1. Rear leaf spring assembly; 2. Cover plate; 3. Balance shaft bracket; 4. U-bolt; 5. First sliding plate; 6. Second sliding plate; 7. Frame; 8. First rear axle; 9. Second rear axle; 100. Main leaf spring structure; 12. Leaf spring body; 13. First reinforcing component; 14. Second reinforcing component; 10. First airbag; 15. First mounting base; 11. Second airbag; 16. Second mounting base; 17. First guide seat; 18. Second guide seat. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] like Figure 2As shown, this application discloses a balance suspension system, which includes a leaf spring assembly, the leaf spring assembly comprising a main spring structure 100 and a secondary spring structure.

[0032] The main spring structure 100 includes a leaf spring body 12, which is a single-leaf spring structure made of composite material, reducing weight while ensuring stiffness and strength. Both ends of the main spring structure 100 can be slidably inserted into the leaf spring connecting seats on the top surface of the first rear axle 8 and the second rear axle 9, respectively.

[0033] The auxiliary spring structure includes a first airbag 10 and a second airbag 11. Both the first airbag 10 and the second airbag 11 are vertically aligned and are distributed on both sides of the cover plate 2. The top of each airbag is fixed to the frame 7, and the bottom is mounted on the upper surface of the leaf spring body 12.

[0034] Specifically, the leaf spring body 12 is divided into two halves along both sides of the balance shaft bracket 3. One half is located between the balance shaft bracket 3 and the first slide plate 5, and the other half is located between the balance shaft bracket 3 and the second slide plate 6.

[0035] The balance suspension system of this application adopts a combination structure of main spring structure 100 and auxiliary spring structure. Compared with the traditional balance suspension, the leaf spring body 12 is a single-leaf spring structure made of composite material, which greatly reduces the weight while ensuring stiffness and strength, and realizes the lightweighting of the whole vehicle. At the same time, the auxiliary spring structure added to the balance suspension system includes a first airbag 10 and a second airbag 11, which can flexibly adjust the air pressure. When the vehicle is unloaded, it does not affect the smoothness of the ride. When fully loaded or under harsh conditions, the first airbag 10 and the second airbag 11 inflate as needed to bear the load, which can greatly improve reliability and roll stability. That is, it can ensure the vehicle is flexible when unloaded and improve reliability and roll stability when fully loaded or under harsh conditions.

[0036] The balance suspension system of this application uses composite material for the leaf springs, which can ensure the performance of the leaf springs while achieving lightweight; it can ensure smooth ride under no-load conditions, reliability under full-load conditions, and roll stability; it can ensure reliability under harsh conditions such as overload, bad roads, and mountain curves; it can ensure roll stability under harsh conditions such as overload, bad roads, and mountain curves, and can avoid slippage problems caused by uneven road surfaces.

[0037] In one embodiment, both the first airbag 10 and the second airbag 11 are provided with a limiting block structure. The limiting block structure is vertically arranged from top to bottom, with its top end fixed to the vehicle frame 7 and its bottom end suspended. The limiting block structure does not affect the contraction and expansion of the airbag. During the operation of the first airbag 10 and the second airbag 11, the bottom end face of the limiting block structure is usually detached from the upper surface of the leaf spring body 12. When the rear axle jumps to its extreme position, the limiting block structure abuts against the limiting leaf spring body 12.

[0038] The balanced suspension system of this application cleverly incorporates limiting block structures inside both the first airbag 10 and the second airbag 11, further enhancing the reliability of the suspension system.

[0039] Specifically, the leaf spring connecting seat on the top surface of the first rear axle 8 includes a first sliding plate 5 and a first guide seat 17, and one end of the main spring structure 100 can be slidably inserted between the first sliding plate 5 and the first guide seat 17. The leaf spring connecting seat on the top surface of the second rear axle 9 includes a second sliding plate 6 and a second guide seat 18, and the other end of the main spring structure 100 can be slidably inserted between the second sliding plate 6 and the second guide seat 18. Specifically, during the up-and-down jumping process of the rear axle, the end of the main spring structure 100 slides inside the leaf spring connecting seat.

[0040] In one embodiment, the composite material of the leaf spring body 12 is composed of fiber-reinforced material and thermosetting resin. The fiber-reinforced material is one or more of E-glass fiber, aramid fiber, or basalt fiber, and the thermosetting resin is epoxy resin or PDCPD resin. The density of the leaf spring body 12 is 1.8~2.2 g / cm^3.

[0041] The balanced suspension system of this application uses the aforementioned composite material, which can reduce the weight of the leaf spring body. Specifically, the existing leaf spring body accounts for about 6% of the total vehicle weight, while the one of this application accounts for about 1.5% of the total vehicle weight, meeting the needs of vehicle product upgrades; it can also ensure the performance of the leaf spring body, and can perfectly replace the existing multi-layer alloy steel leaf spring body. The leaf spring body 12 has been verified by a large number of tests to meet various performance requirements such as stiffness and strength.

[0042] Furthermore, the main spring structure 100 also includes a first reinforcing component 13 and a second reinforcing component 14. The first reinforcing component 13 is divided into upper and lower U-shaped plates, which encircle the middle section of the leaf spring body 12 to protect the middle section of the leaf spring body 12 from wear. The second reinforcing component 14 is divided into a channel steel structure and a flat plate structure, which are fixed to the ends of the leaf spring body 12 to protect the ends of the leaf spring body 12 from wear.

[0043] In one embodiment, the auxiliary spring structure further includes a first mounting base 15 and a second mounting base 16, both of which are fixed to the frame 7.

[0044] The top of the first airbag 10 is fixed to the first mounting base 15, and the bottom of the first airbag 10 is fixed to the center of one half of the leaf spring body 12; the top of the second airbag 11 is fixed to the second mounting base 16, and the bottom of the second airbag 11 is fixed to the center of the other half of the leaf spring body 12.

[0045] The balance suspension system of this application, by setting the first mounting seat 15 and the second mounting seat 16, can better arrange and install the first airbag 10 and the second airbag 11.

[0046] In other embodiments, depending on actual needs, the bottom end of the first airbag 10 can also be fixed to one half of the leaf spring body 12 near the first slide plate 5, and the bottom end of the second airbag 11 can be fixed to the other half of the leaf spring body 12 near the second slide plate 6.

[0047] Specifically, the closer the first airbag 10 and the second airbag 11 are to the skateboard, the greater the load they can bear during the process of the airbag and leaf spring jointly bearing the load.

[0048] In one embodiment, the balance suspension system further includes a main solenoid valve, a first solenoid valve, and a second solenoid valve. The input end of the main solenoid valve is connected to the vehicle air source component through a pipeline, and the output end of the main solenoid valve is split into two paths: one path is connected to the first airbag 10 through the first solenoid valve, and the other path is connected to the second airbag 11 through the second solenoid valve.

[0049] The main solenoid valve controls the air pressure output from the vehicle's air supply components, the first solenoid valve controls the air pressure input to the first airbag 10, and the second solenoid valve controls the air pressure input to the second airbag 11. During actual operation, the main solenoid valve, the first solenoid valve, and the second solenoid valve are adjusted according to different operating conditions, such as the vehicle being unloaded, fully loaded, or traveling on rough roads.

[0050] In one embodiment, the first airbag 10 is equipped with a first air pressure sensor, and the second airbag 11 is equipped with a second air pressure sensor. Both the first and second air pressure sensors are connected to the driver's cab ECU. The first and second air pressure sensors monitor the airbag pressure in real time and feed the pressure value back to the driver's cab ECU.

[0051] In one embodiment, the balance suspension system further includes cab knobs k1, k2, and k3 disposed in the cab. Cab knob k1 controls the opening of the master solenoid valve, cab knob k2 controls the opening of the first solenoid valve, and cab knob k3 controls the opening of the second solenoid valve.

[0052] Specifically, the cab knob k1 controls the output air pressure of the main solenoid valve, the cab knob k2 controls the output air pressure of the first solenoid valve, and the cab knob k3 controls the output air pressure of the second solenoid valve. The air pressure output by the first and second solenoid valves is not greater than the air pressure output by the main solenoid valve.

[0053] In one embodiment, the cab knob k1 includes at least three positions: a zero-pressure position for an unloaded vehicle, a set pressure position for a fully loaded vehicle, and a maximum pressure position equal to the air pressure inside the vehicle's air supply components. When the cab knob k1 is in the zero-pressure position, the air pressure output by the main solenoid valve is zero; in the set pressure position, the main solenoid valve outputs the set pressure; and in the maximum pressure position, the air pressure output by the main solenoid valve is equal to the air pressure inside the vehicle's air supply components.

[0054] The cab knobs K2 and K3 have at least two positions: neutral and full. In neutral, the first and second solenoid valves are inactive, and the output air pressure equals the output air pressure of the main solenoid valve. In full, the opening of both solenoid valves is zero, and the output air pressure is zero. In another embodiment, additional air pressure settings can be added according to load requirements.

[0055] The balanced suspension system of this application uses the output air pressure of the main solenoid valve via the cab knob k1, the output air pressure of the first solenoid valve via the cab knob k2, and the output air pressure of the second solenoid valve via the cab knob k3. The output air pressure can be flexibly adjusted to adapt to different driving conditions, and can improve the full-load reliability and roll stability without affecting the ride comfort.

[0056] Furthermore, the cab ECU is used to calibrate and convert the air pressure value obtained from the first air pressure sensor into axle load information for the first rear axle 8, and also to calibrate and convert the air pressure value obtained from the second air pressure sensor into axle load information for the second rear axle 9. The two axle load information are then summed and displayed on the instrument panel. When the sum of the two axle load information exceeds a preset range (pre-set), the cab ECU issues an alarm. Specifically, the cab ECU determines whether the sum of the two axle load information exceeds the preset range. When the cab ECU issues an alarm, the alarm is displayed on the instrument panel with flashing warning signs.

[0057] Specifically, both the first airbag 10 and the second airbag 11 are equipped with air pressure sensors, which transmit air pressure signals to the cab ECU. The cab ECU is pre-calibrated, and upon receiving the air pressure signal, it outputs rear axle load information to monitor the middle and rear axle loads, thereby further enhancing reliability.

[0058] Specifically, the failure mode of the composite leaf spring body is stiffness reduction → local delamination cracking → overall delamination cracking. This failure is not easily detected in its early stages, leading to secondary failures in other components. During loading, users can determine if the composite leaf spring body is abnormal based on the rear axle load. By judging whether the rear axle load exceeds the set range, they can indirectly deduce a failure due to stiffness reduction in the leaf spring body. This is because reduced stiffness leads to increased airbag load and increased internal air pressure, resulting in an output axle load greater than the actual axle load.

[0059] In this application, the cab ECU calibrates the received air pressure value and converts it into rear axle load information, and displays the sum of the two rear axle load information on the instrument panel. When the sum of the two rear axle load information exceeds the set range (pre-set), the cab ECU alarms. It can indirectly determine whether the composite leaf spring body has failed through the rear axle load, making early prediction and further enhancing reliability.

[0060] The working principle of the balance suspension system in this application is as follows:

[0061] When unloaded, the first airbag 10 and the second airbag 11 do not bear any load, and only the main spring structure 100 works, which does not affect the ride comfort of the suspension.

[0062] When fully loaded, the first airbag 10, the second airbag 11, and the main spring structure 100 work together to bear the load.

[0063] As the vehicle load gradually increases, the first airbag 10 and the second airbag 11 are compressed, increasing the stiffness of the first airbag 10 and the second airbag 11 while the stiffness of the main spring structure 100 remains unchanged. This results in a redistribution of the load, with most of the load being transferred to the rear axle through the airbags and then through the end of the main spring structure 100. A small portion of the load needs to be borne by the main spring structure 100 itself, which effectively avoids the situation where the main spring structure 100 fails due to excessive load in harsh working conditions such as overload, bad roads, and mountain bends.

[0064] At the same time, such as Figure 3 As shown, the leaf spring assembly consisting of the main spring structure 100 and the auxiliary spring structure has increased stiffness compared to the traditional rear leaf spring assembly 1, which can increase the roll angle stiffness of the balance suspension system, thereby improving the vehicle's roll stability under harsh conditions such as overload, bad roads, and mountain curves. Specifically, the load and displacement variation curves of the balance suspension system are shown in [the diagram]. Figure 3 Point A is the starting point where the air spring begins to bear the load; point B is the rear axle upper bounce limit point in the balance suspension system of this application; and point C is the rear axle upper bounce limit point in the prior art balance suspension system.

[0065] As can be seen from the figure, before the air spring takes on its load-bearing function (i.e., before point A), the load-displacement change curves of the balance suspension system of this application and the balance suspension system of the prior art are the same. After the air spring takes on its load-bearing function (i.e., after point A), a comparison between curve AB corresponding to the balance suspension system of this application and straight line AC corresponding to the balance suspension system of the prior art shows that under the same load, the balance suspension system of this application has a smaller displacement, and the balance suspension system of the prior art has not reached the ultimate load even after reaching the ultimate displacement point C.

[0066] The balanced suspension system of this application adopts a combination structure of main spring structure 100 and auxiliary spring structure. Compared with the traditional balanced suspension, the leaf spring body 12 is a single-leaf spring structure made of composite material, which greatly reduces the weight while ensuring stiffness and strength, and realizes the lightweighting of the whole vehicle. At the same time, the auxiliary spring structure added to the balanced suspension system includes a first airbag 10 and a second airbag 11, which can flexibly adjust the air pressure. It does not affect the smoothness under no-load conditions. Under full load or harsh conditions, the first airbag 10 and the second airbag 11 inflate as needed to bear the load, which can greatly improve reliability and roll stability, thereby improving the service life and comfort of the vehicle and increasing the value for customers.

[0067] Meanwhile, both the first airbag 10 and the second airbag 11 are equipped with limiting block structures. These limiting block structures are vertically arranged from top to bottom, with their top ends fixed to the vehicle frame 7 and their bottom ends suspended. The limiting block structures do not affect the contraction and expansion of the airbags. During the operation of the first airbag 10 and the second airbag 11, the bottom surface of the limiting block structure is normally detached from the upper surface of the leaf spring body 12. When the rear axle jumps to its extreme position, the limiting block structure abuts against the limiting leaf spring body 12.

[0068] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0069] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0070] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A balanced suspension system, characterized in that: The balance suspension system includes The leaf spring assembly includes a main leaf spring structure (100) and a secondary leaf spring structure. The main leaf spring structure (100) includes a leaf spring body (12), which is a single leaf spring structure made of composite material. The two ends of the main leaf spring structure (100) are respectively slidably inserted into the leaf spring connecting seat on the top surface of the first rear axle (8) and the leaf spring connecting seat on the top surface of the second rear axle (9). The secondary leaf spring structure includes a first airbag (10) and a second airbag (11). The two airbags are vertically arranged and distributed on both sides of the cover plate (2). The top end of each airbag is fixed to the frame (7) and the bottom end is installed on the upper surface of the leaf spring body (12). The first airbag (10) is equipped with a first air pressure sensor, and the second airbag (11) is equipped with a second air pressure sensor. Both the first air pressure sensor and the second air pressure sensor are connected to the ECU in the driver's cab. The first air pressure sensor and the second air pressure sensor monitor the airbag pressure in real time and feed the air pressure value back to the ECU in the driver's cab. The cab ECU is used to calibrate and convert the air pressure value obtained from the first air pressure sensor into the axle load information of the first rear axle (8), and is also used to calibrate and convert the air pressure value obtained from the second air pressure sensor into the axle load information of the second rear axle (9), and then sum the two axle load information and display it on the instrument panel; when the sum of the two axle load information exceeds the set range, the cab ECU alarms, thereby determining whether the composite leaf spring body has failed by the rear axle load.

2. The balanced suspension system as described in claim 1, characterized in that: The first airbag (10) and the second airbag (11) are both provided with limiting block structures from top to bottom, and the top of the limiting block structure is fixed to the vehicle frame (7).

3. A balanced suspension system as described in claim 1, characterized in that: The leaf spring connecting seat on the top surface of the first rear axle (8) includes a first sliding plate (5) and a first guide seat (17), and one end of the main spring structure (100) is slidably inserted between the first sliding plate (5) and the first guide seat (17); the leaf spring connecting seat on the top surface of the second rear axle (9) includes a second sliding plate (6) and a second guide seat (18), and the other end of the main spring structure (100) is slidably inserted between the second sliding plate (6) and the second guide seat (18).

4. A balanced suspension system as described in claim 1, characterized in that: The composite material of the leaf spring body (12) is made of fiber-reinforced material and thermosetting resin. The fiber-reinforced material is one or more of E-glass fiber, aramid fiber or basalt fiber. The thermosetting resin is epoxy resin or PDCPD resin. The density of the leaf spring body (12) is 1.8~2.2 g / cm^3. The main spring structure (100) also includes a first reinforcing component (13) and a second reinforcing component (14). The first reinforcing component (13) is divided into upper and lower U-shaped plates, and the upper and lower U-shaped plates surround the middle section of the leaf spring body (12). The second reinforcing component (14) is divided into a channel steel structure and a flat plate structure, and the channel steel structure and the flat plate structure surround and fix to the end of the leaf spring body (12).

5. A balanced suspension system as described in claim 1, characterized in that: The auxiliary spring structure also includes a first mounting seat (15) and a second mounting seat (16), both of which are fixed to the frame (7). The top end of the first airbag (10) is fixed to the first mounting base (15), and the bottom end is fixed to the center of one half of the leaf spring body (12); the top end of the second airbag (11) is fixed to the second mounting base (16), and the bottom end is fixed to the center of the other half of the leaf spring body (12).

6. A balanced suspension system as described in claim 1, characterized in that: The balance suspension system also includes a main solenoid valve, a first solenoid valve and a second solenoid valve. The input end of the main solenoid valve is connected to the vehicle air source component through a pipeline. The output end of the main solenoid valve is split into two paths, one of which is connected to the first airbag (10) through the first solenoid valve and the other of which is connected to the second airbag (11) through the second solenoid valve. The main solenoid valve is used to control the air pressure output by the vehicle's air source components, the first solenoid valve is used to control the air pressure input to the first airbag (10), and the second solenoid valve is used to control the air pressure input to the second airbag (11).

7. A balanced suspension system as described in claim 1, characterized in that: The balance suspension system also includes a cab knob k1, a cab knob k2, and a cab knob k3 located in the cab; the cab knob k1 controls the output air pressure of the main solenoid valve, the cab knob k2 controls the output air pressure of the first solenoid valve, and the cab knob k3 controls the output air pressure of the second solenoid valve.

8. A balanced suspension system as described in claim 7, characterized in that: The cab knob k1 has at least three positions: zero air pressure for unloaded vehicles, set air pressure for fully loaded vehicles, and maximum air pressure equivalent to the air pressure inside the vehicle's air source components. The cab knobs k2 and k3 each have at least two positions: neutral and full.

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