Multi-link rear suspension system, chassis and vehicle

Abstract

The application discloses a multi-link rear suspension system, a chassis and a vehicle, and relates to the technical field of vehicles.The multi-link rear suspension system comprises a subframe, a steering knuckle configured to be connected with a wheel, a rear wheel steering gear connected with the subframe and arranged close to a suspension kingpin, an upper control arm assembly with two ends connected with the steering knuckle and the subframe respectively, a lower control arm assembly with two ends connected with the steering knuckle and the subframe respectively, a toe control arm with two ends connected with the steering knuckle and an output end of the rear wheel steering gear respectively, an air spring with a lower end connected with the lower control arm assembly and an upper end configured to be connected with a vehicle body, the air spring being connected close to the steering knuckle, and a shock absorber with a lower end connected with the steering knuckle and an upper end configured to be connected with the vehicle body, the shock absorber being arranged independently from the air spring.The application can realize a larger wheel rotation angle under the same stroke of the rear wheel steering gear and reduce the turning diameter of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a multi-link rear suspension system, a chassis and a vehicle. BACKGROUND

[0002] A multi-link rear suspension system is usually used in high-end medium and large cars, and the multi-link rear suspension system adopts a rear sliding column form of spring and damper separation (i.e., spring and damper are arranged separately) to solve the problem of large space occupation in the vehicle transversely in the traditional suspension structure of the integrated spring and damper sliding column, so as to realize a larger luggage compartment width under the condition of limited vehicle width.

[0003] With the gradual popularization of rear wheel steering technology, the spring and damper separated multi-link rear suspension system can be equipped with a rear wheel steering system, thereby improving the driving stability of the vehicle when turning at high speed, and the flexibility when driving at low speed, reducing the turning radius of the vehicle, and being beneficial to make up for the driving danger caused by excessive steering. However, in the structure design of the existing spring and damper separated multi-link rear suspension system, the steering angle of the rear wheel is small, which leads to limited improvement of the stability and flexibility of the vehicle. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a multi-link rear suspension system, a chassis and a vehicle, which realizes a larger wheel angle under the same stroke of the rear wheel steering gear and reduces the turning diameter of the vehicle.

[0005] The first aspect of the present application provides a multi-link rear suspension system, comprising:

[0006] a subframe;

[0007] a knuckle configured to be connectable with a wheel;

[0008] a rear wheel steering gear connected with the subframe and arranged close to a suspension kingpin;

[0009] an upper control arm assembly, two ends of which are respectively connected with the knuckle and the subframe;

[0010] a lower control arm assembly, two ends of which are respectively connected with the knuckle and the subframe;

[0011] a toe control arm, two ends of which are respectively connected with the knuckle and an output end of the rear wheel steering gear;

[0012] an air spring, a lower end of which is connected with the lower control arm assembly, and an upper end of which is configured to be connectable with a vehicle body, the air spring being connected close to the knuckle;

[0013] A shock absorber is connected with the knuckle at its lower end and configured to be connected with the vehicle body at its upper end, and the shock absorber and the air spring are independently arranged.

[0014] The multi-link rear suspension system according to the first aspect of the present application has at least the following beneficial effects: the upper control arm assembly and the lower control arm assembly are arranged between the subframe and the knuckle, so that the knuckle is stable relative to the subframe and movable relative to the subframe; the rear wheel steering gear is arranged on the subframe; and the toe control arm is arranged between the rear wheel steering gear and the knuckle, so that the rear wheel steering gear drives the knuckle to swing the rear wheel through the toe control arm, thereby realizing the steering function of the rear wheel.

[0015] The shock absorber is connected with the knuckle, and the air spring is connected with the lower control arm assembly and arranged close to the knuckle, so that the lever ratio of the air spring is increased, the stiffness of the air spring is reduced under the condition of realizing the same suspension natural frequency, the diameter of the air spring is reduced, the required arrangement space of the air spring is effectively reduced, the shock absorber is arranged closer to the kingpin of the suspension relative to the air spring, the tire envelope of the shock absorber is smaller during the rear wheel steering, the overall width of the vehicle is reduced, and the steering angle of the rear wheel is increased.

[0016] On this basis, the rear wheel steering gear is arranged close to the kingpin of the suspension, and the length of the toe control arm is shortened, so that the driving arm is shorter during the operation of the rear wheel steering gear and the driving of the rear wheel around the kingpin of the suspension, and a larger rear wheel steering angle is realized under the condition of using the rear wheel steering gear with the same stroke, thereby reducing the turning diameter of the vehicle.

[0017] In some embodiments of the present application, the air spring is a double-cavity air spring, and the lever ratio of the air spring is 0.65; and / or the lower control arm assembly is provided with a mounting groove with an upward opening, and the lower end of the air spring is arranged in the mounting groove.

[0018] In some embodiments of the present application, the shock absorber is arranged between the knuckle and the air spring.

[0019] In some embodiments of the present application, the central axis of the shock absorber and the upward and downward direction form a first acute angle, and the upper end of the shock absorber is arranged in a direction away from the knuckle.

[0020] In some embodiments of the present application, the central axis of the air spring and the upward and downward direction form a second acute angle, and the upper end of the air spring is arranged in a direction away from the knuckle.

[0021] In some embodiments of the present application, the first acute angle is equal to the second acute angle.

[0022] In some embodiments of the present application, the upper control arm assembly comprises a first upper control arm and a second upper control arm, two ends of the first upper control arm are connected with the knuckle and the sub-frame respectively, and two ends of the second upper control arm are connected with the knuckle and the sub-frame respectively.

[0023] In some embodiments of the present application, the lower control arm assembly comprises a first lower control arm and a second lower control arm, two ends of the first lower control arm are connected with the knuckle and the sub-frame respectively, two ends of the second lower control arm are connected with the knuckle and the sub-frame respectively, the second lower control arm is located between the first lower control arm and the toe control arm, and the air spring is connected with the second lower control arm.

[0024] In some embodiments of the present application, the knuckle comprises a connecting part extending towards the second lower control arm, the connecting part is provided with a first connecting hole and a second connecting hole, the second lower control arm is connected with the first connecting hole, and the shock absorber is connected with the second connecting hole.

[0025] In some embodiments of the present application, the first connecting hole is located above the second connecting hole, and the second connecting hole is located on a side of the first connecting hole close to the knuckle.

[0026] In some embodiments of the present application, the connecting part is connected with the knuckle through a bolt, the connecting part is provided with a positioning convex part and a positioning flat surface, the positioning convex part is in the shape of a truncated cone or a hemisphere, the positioning convex part is provided with a third connecting hole, the knuckle is provided with a positioning recess, a fourth connecting hole and a positioning block, the fourth connecting hole is in communication with the positioning recess, the positioning convex part and the positioning recess are adaptively connected, the positioning block is in contact with the positioning flat surface, so that the positioning convex part is radially positioned, and the bolt passes through the fourth connecting hole and is connected with the third connecting hole.

[0027] In some embodiments of the present application, the positioning block is provided with two positioning blocks located on opposite sides of the positioning recess respectively.

[0028] In some embodiments of the present application, the multi-link rear suspension system further comprises a rear stabilizer and a connecting rod, the rear stabilizer is connected with the sub-frame, the connecting rod is provided on both sides of the rear stabilizer, and two ends of the connecting rod are connected with the rear stabilizer and the knuckle respectively.

[0029] The second aspect embodiment of the present application provides a chassis comprising the multi-link rear suspension system of the first aspect embodiment.

[0030] The chassis according to the second aspect of the present application has at least the following beneficial effects: the chassis adopts the multi-link rear suspension system according to the first aspect of the present application, and can increase the steering angle of the wheels under the same driving stroke of the rear wheel steering gear, thereby reducing the turning diameter of the whole vehicle, and improving the driving stability and flexibility of the vehicle, and reducing the driving risk.

[0031] The third aspect of the present application provides a vehicle comprising the chassis according to the second aspect of the present application.

[0032] The vehicle according to the third aspect of the present application has at least the following beneficial effects: the vehicle adopts the chassis according to the second aspect of the present application, and can achieve a larger wheel steering angle under the configuration of the rear wheel steering gear with the same stroke, so that the turning diameter of the whole vehicle is smaller, the driving stability of the vehicle at high speed is improved, the flexibility of the vehicle at low speed is improved, and the driving risk caused by excessive steering is compensated.

[0033] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structure schematic diagram of a multi-link rear suspension system provided by the prior art after being installed on a vehicle;

[0035] Figure 2 is a structure schematic diagram of a multi-link rear suspension system provided by the present application after being installed on a vehicle;

[0036] Figure 3 is a three-dimensional structure schematic diagram of a multi-link rear suspension system provided by the present application;

[0037] Figure 4 is a schematic diagram of the installation of a shock absorber and an air spring provided by the prior art;

[0038] Figure 5 is a schematic diagram of the installation of a shock absorber and an air spring provided by the present application;

[0039] Figure 6 is a three-dimensional structure schematic diagram of a second lower control arm provided by the present application;

[0040] Figure 7 is a three-dimensional structure schematic diagram of a knuckle provided by the present application;

[0041] Figure 8 is a structure exploded view of a knuckle provided by the present application.

[0042] 100, wheel; 200, slide column assembly; 210, shock absorber; 220, air spring; 300, subframe; 400, knuckle; 410, connecting portion; 411, first connecting hole; 412, second connecting hole; 413, positioning protrusion; 420, mounting portion; 430, bolt; 441, positioning block; 442, positioning groove; 500, whole vehicle symmetry plane; 610, first lower control arm; 620, second lower control arm; 621, first arm portion; 622, second arm portion; 623, mounting groove; 630, toe control arm; 640, second upper control arm; 650, first upper control arm; 660, rear stabilizer bar; 670, connecting rod; 700, rear wheel steering gear. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below with reference to examples illustrated in the accompanying drawings, in which the same or similar components are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the drawings are exemplary and are for the purpose of explanation only and are not to be understood as limiting the present application.

[0044] In the description of the present application, it is to be understood that the features defined with "first", "second" can include one or more of the features explicitly or implicitly. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0045] In the description of the present application, it is to be understood that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] The suspension system is a general term for all force transmission connecting devices between the frame (or the body) of the automobile and the axle (or the wheel), generally, the suspension system mainly consists of elastic elements, guide mechanisms and shock absorbers, etc. The function of the suspension system is to transmit the force and torque between the wheel and the frame, and to buffer the impact force from the uneven road to the frame or the body, and to reduce the vibration caused thereby, so as to ensure smooth driving of the automobile.

[0047] The classification of the suspension system includes independent suspension system, non-independent suspension system and active suspension system. Among them, the independent suspension system includes wishbone suspension system, multi-link suspension system, trailing arm suspension system, candle suspension system, Macpherson suspension system and trailing arm suspension system.

[0048] At present, the multi-link rear suspension system, especially the five-link rear suspension system, is a common rear suspension form in high-end medium and large passenger cars. As shown in Figure 1 , in the traditional five-link rear suspension structure, the slide column assembly 200 with spring and damper integrated structure (i.e. spring and damper integrated design) occupies a large space in the vehicle transversely, in order to realize a larger luggage compartment width L under the condition of limited vehicle width, the five-link rear suspension system structure usually adopts the rear slide column form with spring and damper separated structure (i.e. spring and damper separated design) as shown in Figure 2 .

[0049] It can be understood that Figure 1 and Figure 2 only show half of the structure of the multi-link rear suspension system installed at the rear of the vehicle, and the overall structure of the multi-link rear suspension system is symmetrically arranged about the symmetry plane 500 of the vehicle.

[0050] In recent years, with the gradual popularization of air springs and rear wheel steering technology, the five-link rear suspension system with spring and damper separated structure can be equipped with air springs and rear wheel steering system. Among them, the air spring is light in mass, stable in dynamic performance, long in service life and high in reliability, which can improve the riding comfort of the vehicle, improve the riding comfort of the vehicle, and reduce the deformation of the rear suspension system. The rear wheel steering system can improve the driving stability of the vehicle at high speed and the flexibility at low speed, reduce the turning radius of the vehicle, and help to compensate for the driving risk caused by excessive steering.

[0051] Compared with the coil spring, the diameter of the air spring is greatly increased, especially in the case of configuring a double-cavity air spring. In order to achieve better driving experience, the high and low stiffness difference of the double-cavity air spring will be as large as possible, and the larger stiffness target requires the air spring to have a larger layout space, so the rear suspension system needs to provide a larger installation space for the air spring. The configuration of the rear wheel steering system will cause the movement range of the tire to increase. The above factors have brought great difficulties to the layout of the five-link rear suspension system with spring and damper separated structure, resulting in the increase of the overall width of the vehicle, leading to the increase of the weight, cost and selling price of the vehicle.

[0052] Based on this, in the structure design of the existing multi-link rear suspension system with spring and damper separated structure, the steering angle of the rear wheel is designed to be small, which will limit the improvement degree of the stability and flexibility of the vehicle.

[0053] Based on the above technical problems, the embodiment of the present application provides a multi-link rear suspension system, a chassis and a vehicle, which can realize a larger wheel rotation angle under the same stroke of the rear wheel steering gear, thereby reducing the turning diameter of the whole vehicle and reducing the driving risk when the vehicle is excessively turned.

[0054] Reference will be made to the drawings below Figures 1 to 8 The multi-link rear suspension system, the chassis and the vehicle provided by the embodiment of the present application are described.

[0055] As Figure 2 and Figure 3 、 Figures 5 to 8 The multi-link rear suspension system according to the first aspect of the present application can be mass-produced and applied to the rear suspension structure of a three-box sedan.

[0056] The multi-link rear suspension system of the embodiment includes a subframe 300, a steering knuckle 400, a rear wheel steering gear 700, an upper control arm assembly, a lower control arm assembly, a toe control arm 630, an air spring 220 and a shock absorber 210.

[0057] The structure of the subframe 300 includes cross beams and longitudinal beams. The number of cross beams is two, and the two cross beams are arranged at a certain interval along the front-rear direction, and each cross beam extends along the left-right direction. The number of longitudinal beams is two, and the two longitudinal beams are arranged at a certain interval along the left-right direction, and the two cross beams are symmetrically arranged left and right, and each longitudinal beam extends along the front-rear direction. Two ends of each longitudinal beam are fixedly connected with two cross beams, and all cross beams and all longitudinal beams are integrally formed. One of the cross beams extends horizontally along the left-right direction to form a first connecting arm, and the first connecting arm can be fixedly connected with the vehicle body by suspension. The other cross beam extends away from the longitudinal beam along the left-right direction to form a second connecting arm, and the second connecting arm can be fixedly connected with the vehicle body by suspension.

[0058] It can be understood that the two cross beams and the two longitudinal beams together enclose an installation space, which is through from top to bottom, and the installation space is used for installing a motor. The output shaft of the motor can drive the two rear wheels to rotate to realize the rear wheel drive function of the vehicle. The subframe 300 can be made of aluminum alloy material and adopt integral hollow casting process, which is light in weight, saves welding steps and improves production efficiency.

[0059] The knuckle 400 is configured to be connected with the wheel 100. The side of the knuckle 400 close to the subframe 300 is the inner side, and the side of the knuckle 400 away from the subframe 300 is the outer side. The wheel 100 is located at the outer side of the knuckle 400, and the wheel 100 can be installed in the mounting shaft hole provided in the knuckle 400 through the hub bearing, so that the wheel 100 can rotate around the wheel center relative to the knuckle 400. Moreover, the knuckle 400 can drive the wheel 100 to swing around the suspension pivot. It can be understood that the knuckle 400 can be made of aluminum alloy material, and the forming work of the knuckle 400 can be completed by using the casting and forging process, so that the knuckle 400 has better mechanical properties.

[0060] The rear wheel steering gear 700 is connected with the subframe 300, and the rear wheel steering gear 700 is arranged close to the suspension pivot. Specifically, the rear wheel steering gear 700 is connected with the subframe 300 through bolts, and the rear wheel steering gear 700 is arranged at the middle position of one of the beams of the subframe 300 and between the two second connecting arms.

[0061] It can be understood that the suspension pivot is the rotation axis of the wheel 100 when the wheel 100 turns, and the suspension pivot plays a very important role in the steering performance of the automobile. By arranging the suspension pivot as close as possible to the rear wheel steering gear 700, when the rear wheel steering gear 700 operates, the rear wheel can rotate around the rotation center thereof, i.e., the suspension pivot, and the driving arm is shorter, so that the same rack stroke of the rear wheel steering gear 700 can be used to achieve a larger rear wheel turning angle, and the turning diameter of the whole vehicle can be reduced.

[0062] One end of the upper control arm assembly is connected with the knuckle 400, and the other end of the upper control arm assembly is connected with the subframe 300. In the embodiment, the upper control arm assembly includes a first upper control arm 650 and a second upper control arm 640. The two ends of the first upper control arm 650 are respectively connected with the knuckle 400 and the subframe 300, and the two ends of the second upper control arm 640 are respectively connected with the knuckle 400 and the subframe 300.

[0063] Specifically, the outer end of the first upper control arm 650 is hinged with the upper part of the knuckle 400 through a bushing, and the inner end of the first upper control arm 650 is hinged with the mounting lug provided in the longitudinal beam of the subframe 300 through a bushing. The outer end of the second upper control arm 640 is hinged with the upper part of the knuckle 400 through a bushing, and the inner end of the second upper control arm 640 is hinged with the middle position of the longitudinal beam of the subframe 300 through a bushing, and the middle position of the longitudinal beam is provided with a mounting lug for connecting with the second upper control arm 640. The second upper control arm 640 is closer to the suspension pivot and the rear wheel steering gear 700 than the first upper control arm 650.

[0064] One end of the lower control arm assembly is connected with the knuckle 400, and the other end of the lower control arm assembly is connected with the subframe 300. In the embodiment, the lower control arm assembly comprises a first lower control arm 610 and a second lower control arm 620. The two ends of the first lower control arm 610 are respectively connected with the knuckle 400 and the subframe 300, and the two ends of the second lower control arm 620 are respectively connected with the knuckle 400 and the subframe 300. Moreover, the second lower control arm 620 is located between the first lower control arm 610 and the toe control arm 630, and the air spring 220 is connected with the second lower control arm 620.

[0065] Specifically, the outer end of the first lower control arm 610 is hinged with the lower part of the knuckle 400 through a bushing, and the inner end of the first lower control arm 610 is hinged with the lower part of the subframe 300 through a bushing. The hinged position of the first lower control arm 610 and the subframe 300 is located at the end of the longitudinal beam away from the rear wheel steering gear 700. The outer end of the second lower control arm 620 is hinged with the lower part of the knuckle 400 through a bushing, and the inner end of the second lower control arm 620 is hinged with the lower part of the subframe 300 through a bushing. The hinged position of the second lower control arm 620 and the subframe 300 is located at the position of the cross beam corresponding to the front and rear of the output shaft of the rear wheel steering gear 700.

[0066] It can be understood that in the embodiment, the first upper control arm 650, the second upper control arm 640 and the first lower control arm 610 are all single-arm structures, and the second lower control arm 620 can be H-shaped, as shown in Figure 6 Since the first upper control arm 650, the second upper control arm 640, the first lower control arm 610 and the second lower control arm 620 are connected with the knuckle 400, the knuckle 400 is a five-link knuckle, and the multi-link rear suspension system is a five-link rear suspension system. Of course, it is not excluded that the multi-link rear suspension system can be a four-link rear suspension system.

[0067] In the embodiment, the multi-link rear suspension system is a five-link rear suspension system, which has the advantages of lighter weight, lower cost, closer distance between the suspension kingpin and the wheel center, and reduced disturbance effect of road excitation on the wheel 100 compared with the H-arm rear suspension.

[0068] The two ends of the toe control arm 630 are respectively connected with the knuckle 400 and the output end of the rear wheel steering gear 700. Specifically, the outer end of the toe control arm 630 is hinged with the knuckle 400 through a bushing, and the inner end of the toe control arm 630 is connected with the output end of the rear wheel steering gear 700 through a bolt. Therefore, when the rear wheel steering gear 700 works, the rear wheel steering gear 700 can drive the toe control arm 630 to move, so that the toe control arm 630 can drive the knuckle 400 to swing around the suspension kingpin.

[0069] In the embodiment, the knuckle 400 extends towards a direction away from the hinging position with the first upper control arm 650, and forms an extension arm portion, which is provided with a bushing mounting hole for connecting with the toe control arm 630. The toe control arm 630 is a single-arm structure.

[0070] It can be understood that, when the knuckle 400, the upper control arm assembly, the lower control arm assembly and the toe control arm 630 are determined, the suspension kingpin of the multi-link rear suspension system can be determined according to the connection relationship therebetween. The suspension kingpin can be determined through existing kinematic model simulation technology and some mathematical calculation methods.

[0071] The lower end of the air spring 220 is connected with the lower control arm assembly, and the upper end of the air spring 220 is configured to be connected with the vehicle body, and the air spring 220 is connected close to the knuckle 400.

[0072] Specifically, the lower end of the air spring 220 is fixedly connected with the second lower control arm 620, and the upper end of the air spring 220 is fixedly connected with the vehicle body, so that the multi-link rear suspension system is prevented from being out of the vehicle body during movement through air pressure. In addition, the lever ratio of the air spring 220 is greater than 0.5.

[0073] In the embodiment, the air spring 220 is located on the side of the second connecting arm close to the longitudinal beam.

[0074] In the common five-link rear suspension system with the air spring 220 and the spring-reduction separation design, the lever ratio of the air spring 220 is 0.5. In comparison, in the embodiment, the lever ratio of the air spring 220 is designed to be greater than 0.5, so that the lever ratio of the air spring 220 is increased, and the stiffness requirement of the air spring 220 is reduced in the case of achieving the same suspension natural frequency. The lower the stiffness of the air spring 220 is, the smaller the diameter is, and therefore, the five-link rear suspension system provided in the embodiment can effectively reduce the required arrangement space of the air spring 220.

[0075] The shock absorber 210 and the air spring 220 are independently arranged, and therefore, the shock absorber 210 is not included in the shock absorber assembly 200. The lower end of the shock absorber 210 is connected with the knuckle 400, and the upper end of the shock absorber 210 is configured to be connected with the vehicle body. Specifically, the lower end of the shock absorber 210 can be hinged with the lower part of the knuckle 400 through a bushing, and the upper end of the shock absorber 210 is fixedly connected with the vehicle body. It can be understood that the shock absorber 210 can be but is not limited to a semi-active shock absorber 210 or an active shock absorber 210.

[0076] It can be understood that by arranging the air spring 220 on the lower control arm assembly and arranging the shock absorber 210 on the steering knuckle 400, not only the lever ratio of the air spring 220 and the lever ratio of the shock absorber 210 can be increased, but also the lower control arm assembly can only bear the load of the air spring 220 and not bear the load of the shock absorber 210, which is beneficial to realize the lightweight design of the lower control arm assembly. In addition, the high lever ratio of the air spring 220 is beneficial to reduce the internal load of the multi-link rear suspension system and the load transmitted to the vehicle body, and improve the riding comfort of the vehicle.

[0077] Further, the shock absorber 210 is arranged close to the suspension kingpin, so that the tire envelope of the rear wheel relative to the shock absorber 210 is updated during steering, which can further reduce the width dimension of the multi-link rear suspension system.

[0078] In some embodiments, as shown in Figure 3 The multi-link rear suspension system further comprises a rear stabilizer bar 660 and a connecting rod 670. The rear stabilizer bar 660 is connected with the subframe 300, and the connecting rod 670 is arranged on both sides of the rear stabilizer bar 660. The connecting rod 670 is connected with the rear stabilizer bar 660 and the steering knuckle 400 at both ends.

[0079] Specifically, the structure of the rear stabilizer bar 660 comprises a straight part and a bent part. The left and right ends of the straight part are provided with the bent parts, and the bent parts on the left and right sides are symmetrically arranged. The bent part and the straight part are integrally formed. The straight part is connected with the subframe 300 through bolts and is located on the side of the rear wheel steering gear 700 away from the subframe 300 in the front-rear direction. The connecting rod 670 extends upward and downward. The upper end of the connecting rod 670 is connected with the bent part through bolts, and the lower end of the connecting rod 670 is connected with the steering knuckle 400 through bolts. In this embodiment, one of the bent parts is arranged close to the air spring 220 and avoids the air spring 220, as shown in Figure 3 .

[0080] It can be understood that the main function of the rear stabilizer bar 660 is to prevent the vehicle body from excessive lateral roll when turning, and to keep the vehicle body as balanced as possible to improve the comfort and safety of driving. The connecting rod 670 is installed in the upward and downward direction, which is convenient for factory assembly and after-sales maintenance.

[0081] In some embodiments, the air spring 220 is a dual-chamber air spring with a lever ratio of 0.65. In this embodiment, through the arrangement of suspension hardpoints and structural design, the lever ratio of the air spring 220 is achieved at approximately 0.65, reaching or even exceeding the lever ratio of an H-arm (trapezoidal arm) suspension system. While achieving the same suspension skew frequency, the stiffness requirement of the air spring 220 can be reduced by approximately 15%. Since a lower stiffness corresponds to a smaller diameter, the five-link rear suspension system provided in this embodiment effectively reduces the required arrangement space for the air spring 220.

[0082] like Figure 4 As shown, in a common five-link rear suspension system with a spring-damper separation structure, the shock absorber 210 and the air spring 220 are simultaneously arranged on the second lower control arm 620. X0 is the total length of the second lower control arm 620, X1 is the length of the second lower control arm 620 inside the air spring 220, and X2 is the length of the second lower control arm 620 outside the air spring 220. Where X0 = X1 + X2, the leverage ratio of the air spring 220 is approximately X1 / X0, and the leverage ratio of a common five-link rear suspension system is approximately 0.5.

[0083] like Figure 5 As shown, in this embodiment, when the five-link rear suspension system adopts a spring-damper separation structure, the shock absorber 210 is arranged on the steering knuckle 400, and the air spring 220 is arranged on the second lower control arm 620. This can greatly shorten the length dimension X2 of the second lower control arm 620 on the outer side of the air spring 220, which is equivalent to increasing the leverage ratio X1 / X0 of the air spring 220. Therefore, the leverage ratio of the air spring 220 can be increased to about 0.65, which reduces the internal load of the multi-link rear suspension system and the load transmitted to the vehicle body, which is very beneficial to the driving smoothness of the whole vehicle.

[0084] Meanwhile, since the shock absorber 210 is arranged on the steering knuckle 400, the second lower control arm 620 is not subjected to the load of the shock absorber 210, but only to the load of the air spring 220 in the non-two-force bar direction. The load of the air spring 220 is much smaller than the load of the shock absorber 210, which is conducive to achieving a lightweight structural design of the second lower control arm 620.

[0085] In some embodiments, such as Figure 5 and Figure 6 As shown, the lower control arm assembly is provided with a mounting groove 623, the opening of which is open upwards, and the lower end of the air spring 220 is located inside the mounting groove 623.

[0086] In the embodiment, the second lower control arm 620 comprises a first arm portion 621, a second arm portion 622 and a support portion, the support portion is provided with a mounting groove 623, the support portion provides a mounting position for the air spring 220, the first arm portion 621 is located at the inner side of the mounting groove 623, the second arm portion 622 is located at the outer side of the mounting groove 623, and the length dimension of the first arm portion 621 is greater than that of the second arm portion 622.

[0087] It can be understood that the groove depth of the mounting groove 623 can be set according to actual conditions, which is not specifically limited here. Since the height of the air spring 220 is fixed, the upper end of the air spring 220 is fixedly connected to the vehicle body, and the height position of the air spring 220 relative to the second lower control arm 620 is designed to be lower, so that the height dimension of the vehicle compartment can be designed to be higher. By providing the mounting groove 623 on the second lower control arm 620, the groove bottom surface of the mounting groove 623 is lower than the reference surface of the second lower control arm 620, so that the lower end of the air spring 220 can be arranged more downward, the mounting position of the air spring 220 relative to the second lower control arm 620 is lowered, and the height of the vehicle compartment is increased, and the space of the luggage compartment in the height direction is increased.

[0088] In some embodiments, as shown in Figure 3 and Figure 5 , the shock absorber 210 is arranged between the steering knuckle 400 and the air spring 220. The diameter dimension of the lower end of the shock absorber 210 is small, and the shock absorber 210 has little hindering effect on the rear stabilizer bar 660 and the toe control arm 630 relative to the air spring 220, so that the shock absorber 210 is arranged between the steering knuckle 400 and the air spring 220, the shock absorber 210 and the air spring 220 are arranged left and right relative to each other, which can make the structure of the multi-link rear suspension system more compact, and avoid the influence of the shock absorber 210 on the arrangement of the connecting shaft between the second upper control arm 640 and the motor and the wheel 100.

[0089] In some embodiments, as shown in Figure 3 and Figure 5 , the central axis of the shock absorber 210 and the up-down direction form a first acute angle, the first acute angle is α, and the upper end of the shock absorber 210 is arranged obliquely away from the steering knuckle 400. It can be understood that the specific value of the first acute angle α can be set according to actual design. In the embodiment, the first acute angle α is 7°. In this way, when the steering knuckle 400 drives the wheel 100 to rotate around the suspension master pin, the interference and hindering effect of the shock absorber 210 on the steering swing of the wheel 100 can be effectively prevented under the condition of increasing the steering angle of the rear wheel, and the normal steering and rotation of the rear wheel are ensured.

[0090] Moreover, the position of the connection between the shock absorber 210 and the knuckle 400 is lower than the position of the connection between the second lower control arm 620 and the knuckle 400, so that the connection between the shock absorber 210 and the knuckle 400 is arranged in a staggered manner with the connection between the second lower control arm 620 and the knuckle 400 in the up-down direction, which is conducive to increasing the height of the vehicle cabin and reducing the distance between the knuckle 400 and the rear wheel steering gear 700 in the left-right direction, which is equivalent to reducing the distance between the suspension kingpin and the rear wheel steering gear 700 in the left-right direction, so that the length of the toe control arm 630 can be designed to be smaller, so that the driving force arm can be further shortened, and thus, under the condition of using the rear wheel steering gear 700 with the same stroke, the steering angle of the rear wheel is further increased, and the turning diameter of the vehicle is further reduced.

[0091] Further, the central axis of the air spring 220 and the up-down direction form a second acute angle, and the second acute angle is β. The upper end of the air spring 220 is arranged in a tilted manner away from the knuckle 400. It can be understood that the specific value of the second acute angle β can be set according to actual needs. In the embodiment, the second acute angle β is 7°, and the first acute angle α is equal to the second acute angle β. In this way, the shock absorber 210 and the air spring 220 can be stressed in the same direction.

[0092] In some embodiments, as shown in Figure 7 The knuckle 400 includes a connecting portion 410, which extends towards the second lower control arm 620 of the knuckle 400. The connecting portion 410 is provided with a first connecting hole 411 and a second connecting hole 412. The axis of the first connecting hole 411 and the axis of the second connecting hole 412 extend along the front-rear direction. The second lower control arm 620 can be connected to the first connecting hole 411 through a bushing, and the shock absorber 210 can be connected to the second connecting hole 412 through a bushing.

[0093] By providing the connecting portion 410 on the knuckle 400, the position of the connection between the second lower control arm 620 and the knuckle 400 can be as close to the inner side as possible, so that the overall length X0 of the second lower control arm 620 is shortened, and the length of the toe control arm 630 is also shortened accordingly, thereby reducing the overall width of the vehicle. At the same time, by providing the connecting portion 410, the lever ratio of the air spring 220 can reach 0.65.

[0094] In a specific embodiment, as shown in Figure 7As shown, the first connecting hole 411 is located above the second connecting hole 412, and the second connecting hole 412 is arranged on the side of the first connecting hole 411 close to the knuckle 400, that is, the first connecting hole 411 is located on the side of the second connecting hole 412 close to the auxiliary frame 300. In this way, the position of the connection between the lower end of the shock absorber 210 and the knuckle 400 is lower than the position of the connection between the second lower control arm 620 and the knuckle 400, and the connection between the shock absorber 210 and the knuckle 400 and the connection between the second lower control arm 620 and the knuckle 400 are staggered in the up-down direction, which is beneficial to increase the turning angle of the rear wheel and reduce the turning diameter of the vehicle.

[0095] Of course, it is not excluded that the first connecting hole 411 and the second connecting hole 412 are arranged in sequence along the left-right direction and are oppositely arranged.

[0096] In some examples, as shown in FIG. 1, the connecting part 410 is integrally formed with the knuckle 400. In addition, the knuckle 400 is provided with a mounting part 420 located on the side of the connecting part 410 close to the toe control arm 630 in the front-rear direction, and the mounting part 420 is provided with a mounting hole with an axis extending in the up-down direction, and the mounting hole is arranged to connect with the lower end of the connecting rod 670. Figure 7

[0097] In other examples, as shown in FIG. 2, the connecting part 410 is connected with the knuckle 400 through a bolt 430, and the connecting part 410 and the knuckle 400 can be detachably connected. Figure 8

[0098] In addition, the connecting part 410 is provided with a positioning convex part 413 and a positioning flat surface, the positioning convex part 413 is integrally formed with the connecting part 410, the positioning convex part 413 is in the shape of a circular truncated cone or a hemisphere, and the positioning convex part 413 is provided with a third connecting hole provided with an internal thread. The knuckle 400 is provided with a positioning recess 442, a fourth connecting hole, and a positioning block 441, the fourth connecting hole communicates with the positioning recess 442, and the positioning block 441 is integrally formed with the knuckle 400.

[0099] In this embodiment, the positioning convex part 413 is located on the side of the connecting part 410 close to the knuckle 400 in the left-right direction, and the positioning recess 442 is located on the side of the knuckle 400 close to the auxiliary frame 300 in the left-right direction. The axis of the third connecting hole and the axis of the fourth connecting hole both extend in the left-right direction.

[0100] The positioning convex part 413 and the positioning recess 442 are adaptively connected, if the positioning convex part 413 is in the shape of a circular truncated cone, the positioning recess 442 is a recess in the shape of a circular truncated cone; if the positioning convex part 413 is in the shape of a hemisphere, the positioning recess 442 is a recess in the shape of a hemisphere.

[0101] ​​When the positioning protrusion 413 is inserted into the positioning groove 442, the outer surface of the positioning protrusion 413 is in contact with the inner surface of the positioning groove 442, realizing the positioning of the connecting portion 410 in the axial direction of the positioning protrusion 413, so that the positioning protrusion 413 cannot continue to move along the axis thereof. At this time, the positioning block 441 is in contact with the positioning plane to radially position the positioning protrusion 413, so that the positioning protrusion 413 cannot rotate circumferentially around the axis thereof. Then, the bolt 430 is inserted through the fourth connecting hole and connected with the third connecting hole. Of course, the fourth connecting hole can also be provided with an internal thread.

[0102] It can be understood that the positioning block 441 can have an L-shaped positioning reference surface, and the positioning plane is also L-shaped. By making the positioning plane in contact with the positioning reference surface of the positioning block 441, the circumferential rotation of the positioning protrusion 413 can be prevented. Of course, the positioning block 441 can also have a long straight positioning reference surface, and the positioning plane is also long and straight. The positioning block 441 can be located on the upper side, lower side, front side or rear side of the positioning groove 442.

[0103] In a specific example, as shown in Figure 8 the positioning block 441 is provided with two blocks, and the two positioning blocks 441 are respectively located on the opposite sides of the positioning groove 442.

[0104] In this embodiment, the two positioning blocks 441 are symmetrically arranged front and back, one of the positioning blocks 441 is located on the front side of the positioning groove 442, and the other positioning block 441 is located on the rear side of the positioning groove 442. Correspondingly, the connecting portion 410 is provided with two positioning planes, one of which is located on the front side of the connecting portion 410, and the other is located on the rear side of the connecting portion 410. Therefore, when the positioning protrusion 413 is inserted into the positioning groove 442, the two positioning blocks 441 on the front and rear sides can limit the connecting portion 410 in the front and rear directions, so as to avoid the rotation of the connecting portion 410 in the circumferential direction.

[0105] Of course, it is not excluded that the number of positioning blocks 441 is one.

[0106] It can be understood that the detachable arrangement of the connecting part 410 and the knuckle 400 can solve the problem that the overall structure of the knuckle 400 is too long in the lateral direction of the vehicle, thereby increasing the difficulty of manufacturing the overall structure of the knuckle 400 by the low-pressure casting process. In addition, the special positioning structure of the present embodiment can complete the axial positioning and radial positioning of the connecting part 410 on the knuckle 400 by the positioning structure of the positioning convex part 413, the positioning groove 442, the positioning plane, and the positioning block 441, and only one bolt 430 is required for fixation. Compared with the existing positioning method of one face and two pins (two bolts 430 are used), the above structure can save space, weight, and cost, and is beneficial to improving the assembly efficiency of the connecting part 410.

[0107] In the present embodiment, the multi-link rear suspension system is a five-link rear suspension system that simultaneously carries a double-cavity air spring and a rear wheel steering gear 700, and adopts a separate arrangement of the air spring 220 and the shock absorber 210.

[0108] In the multi-link rear suspension system provided in the first embodiment of the present application, the upper control arm assembly and the lower control arm assembly are arranged between the subframe 300 and the knuckle 400, so that the knuckle 400 can be stable relative to the subframe 300 and movable relative to the subframe 300. The rear wheel steering gear 700 is arranged on the subframe 300, and the toe control arm 630 is arranged between the rear wheel steering gear 700 and the knuckle 400, so that the rear wheel steering gear 700 can drive the knuckle 400 to swing the rear wheel through the toe control arm 630, thereby realizing the steering function of the rear wheel.

[0109] The shock absorber 210 and the air spring 220 are arranged independently, the shock absorber 210 is connected with the knuckle 400, and the air spring 220 is connected with the lower control arm assembly and arranged close to the knuckle 400. In this way, the lever ratio of the air spring 220 can be increased, the stiffness of the air spring 220 can be reduced under the condition of realizing the same suspension natural frequency, thereby reducing the diameter of the air spring 220, and correspondingly, the arrangement space of the air spring 220 can be effectively reduced. At the same time, the shock absorber 210 can be arranged closer to the suspension pivot relative to the air spring 220, the tire envelope of the shock absorber 210 is smaller during the rear wheel steering, and the overall width of the vehicle can be reduced. In this way, it is beneficial to increase the steering angle of the rear wheel.

[0110] On the basis of the above structure, the present embodiment can arrange the rear wheel steering gear 700 close to the suspension pivot, thereby shortening the length of the toe control arm 630. During the operation of the rear wheel steering gear 700 and the driving of the rear wheel around the suspension pivot, the driving arm is shorter. Therefore, a larger rear wheel steering angle can be realized under the condition of using the rear wheel steering gear 700 with the same stroke, thereby reducing the turning diameter of the vehicle.

[0111] As Figure 2 , Figure 3 , Figures 5 to 8 indicated, the chassis according to the second aspect embodiment of the present application comprises the multi-link rear suspension system according to the first aspect embodiment.

[0112] The chassis of the vehicle comprises four systems, namely a transmission system, a steering system, a running system and a braking system, wherein the running system comprises a frame, an axle, a wheel 100 and a suspension. In the multi-link rear suspension system of the present embodiment, the wheel 100 is connected to the rear wheel through a steering knuckle 400, and is connected to the vehicle body through a shock absorber 210 and an air spring 220, and is connected to the vehicle body through a subframe 300. The function of the chassis is to support and mount the engine and its components and assemblies of the vehicle, form the overall shape of the vehicle, and receive the power of the engine to make the vehicle move and ensure normal driving.

[0113] The chassis employing the multi-link rear suspension system according to the first aspect embodiment can increase the steering angle of the wheel 100 under the same driving stroke of the rear wheel steering gear 700, thereby reducing the turning diameter of the whole vehicle, which is beneficial to improve the driving stability and flexibility of the vehicle and reduce the driving risk.

[0114] As Figure 2 , Figure 3 , Figures 5 to 8 indicated, the vehicle according to the third aspect embodiment of the present application comprises the chassis according to the second aspect embodiment.

[0115] The vehicle employing the chassis according to the second aspect embodiment can achieve a larger steering angle of the wheel 100 under the same stroke of the rear wheel steering gear 700, so that the turning diameter of the whole vehicle is smaller, which improves the driving stability of the vehicle when turning at high speed and the flexibility of the vehicle when driving at low speed, and makes up for the driving risk caused by excessive steering.

[0116] Specifically, the vehicle can be a private car, such as a sedan, an SUV, an MPV or a pickup truck, etc. The vehicle can also be an operating vehicle, such as a van, a bus, a small truck or a large trailer, etc. The vehicle can be a gasoline vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0117] In the description of the specification, reference to "one embodiment", "some embodiments", "an exemplary embodiment", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "in an exemplary embodiment", "an example", "a specific example", or "some examples" in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0118] Although embodiments of the application have been shown and described, it will be appreciated that those skilled in the art can make various changes, modifications, substitutions and alterations thereto without departing from the principles and scope of the application, which are defined by the claims and their equivalents.

Claims

1. A multi-link rear suspension system, characterized by, The application relates to a vehicle suspension system, comprising: a subframe; a knuckle configured to be connected with a wheel; a rear wheel steering gear connected with the subframe and arranged close to a suspension kingpin; an upper control arm assembly, two ends of which are respectively connected with the knuckle and the subframe; a lower control arm assembly, the lower control arm assembly comprising a first lower control arm and a second lower control arm, two ends of the second lower control arm being respectively connected with the knuckle and the subframe; a toe control arm, two ends of which are respectively connected with the knuckle and an output end of the rear wheel steering gear; an air spring, a lower end of which is connected with the second lower control arm, and an upper end of which is configured to be connected with a vehicle body, the air spring being arranged close to the knuckle; a shock absorber, a lower end of which is connected with the knuckle, and an upper end of which is configured to be connected with the vehicle body, the shock absorber being arranged independently from the air spring, and the connection point of the second lower control arm with the knuckle being closer to a vehicle transverse symmetry plane than the connection point of the shock absorber with the knuckle.

2. The multi-link rear suspension system of claim 1, wherein, The air spring is a double-cavity air spring, and a lever ratio of the air spring is 0.65; and / or the second lower control arm is provided with an upwardly-open mounting groove, and the lower end of the air spring is arranged in the mounting groove.

3. The multi-link rear suspension system of claim 1, wherein, The shock absorber is arranged between the knuckle and the air spring.

4. The multi-link rear suspension system of claim 3, wherein, A central axis of the shock absorber forms a first acute angle with a vertical direction, and the upper end of the shock absorber is arranged in a direction away from the knuckle.

5. The multi-link rear suspension system of claim 4, wherein, A central axis of the air spring forms a second acute angle with the vertical direction, and the upper end of the air spring is arranged in a direction away from the knuckle.

6. The multi-link rear suspension system of claim 5, wherein, The first acute angle is equal to the second acute angle.

7. The multi-link rear suspension system of claim 1, wherein, The upper control arm assembly comprises a first upper control arm and a second upper control arm, two ends of the first upper control arm being respectively connected with the knuckle and the subframe, and two ends of the second upper control arm being respectively connected with the knuckle and the subframe.

8. The multi-link rear suspension system of any one of claims 1 to 7, wherein, Two ends of the first lower control arm are respectively connected with the knuckle and the subframe, and the second lower control arm is arranged between the first lower control arm and the toe control arm.

9. The multi-link rear suspension system of claim 8, wherein, The knuckle comprises a connecting portion, the connecting portion extending in a direction close to the second lower control arm, the connecting portion being provided with a first connecting hole and a second connecting hole, the second lower control arm being connected with the first connecting hole, and the shock absorber being connected with the second connecting hole.

10. The multi-link rear suspension system of claim 9, wherein, The first connecting hole is arranged above the second connecting hole, and the second connecting hole is arranged on a side of the first connecting hole close to the knuckle.

11. The multi-link rear suspension system of claim 10, wherein, The connecting portion and the knuckle are connected through a bolt, the connecting portion being provided with a positioning convex portion and a positioning plane, the positioning convex portion being in a shape of a truncated cone or a hemisphere, the positioning convex portion being provided with a third connecting hole, the knuckle being provided with a positioning recess, a fourth connecting hole and a positioning block, the fourth connecting hole being communicated with the positioning recess, the positioning convex portion and the positioning recess being adaptively connected, the positioning block being in contact with the positioning plane to position the positioning convex portion in a radial direction, and the bolt being connected with the third connecting hole through the fourth connecting hole.

12. The multi-link rear suspension system of claim 11, wherein, The positioning block comprises two positioning blocks arranged on opposite sides of the positioning recess.

13. The multi-link rear suspension system of claim 1, wherein, The rear stabilizer bar is connected with the auxiliary frame, and both sides of the rear stabilizer bar are provided with the connecting rods, and both ends of the connecting rod are connected with the rear stabilizer bar and the steering knuckle respectively.

14. A chassis characterised in that, The multi-link rear suspension system as claimed in any one of claims 1 to 13.

15. Vehicle, characterized in that The chassis as claimed in claim 14.

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