An electric vehicle leaf spring suspension system

Abstract

The application discloses an electric vehicle plate spring suspension system, which comprises a vehicle body, the bottom of the vehicle body comprises a chassis frame, a rear wheel and a plate spring suspension; the rear wheel shaft of the rear wheel is matched with the chassis frame through the plate spring suspension; the plate spring suspension comprises a plate spring frame, the lower side of the plate spring frame is provided with a lower convex arc-shaped plate spring assembly, the rear wheel shaft is below the middle part of the plate spring assembly, and the rear wheel shaft is connected to the lower side of the middle part of the upper plate spring assembly through a detachable connecting assembly; the front lower side of the plate spring assembly is provided with an oblique wheel shaft bounce constraint swing rod, and the oblique wheel shaft bounce constraint swing rod assumes a posture of being high in front and low in back in an initial state; the front end of the wheel shaft bounce constraint swing rod is hinged to the chassis frame through an a hinge, and the rear end of the wheel shaft bounce constraint swing rod is hinged to the rear wheel shaft through a b hinge; the consistency of the rear wheel bounce is improved, and the vehicle control performance is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of vehicle chassis. BACKGROUND

[0002] The leaf spring suspension has the advantages of simple structure, low cost, strong load bearing capacity, etc., and is widely used in the suspension structure of various vehicles. Since the leaf spring is a non-rigid constrained elastic component, under different bumpy road conditions, the leaf spring will not only deform in the up-down direction due to the longitudinal load, but also deform elastically due to the front-rear direction impulse force on the rear wheel, thereby causing the rear wheel to relatively deviate in the front-rear direction in addition to the normal up-down displacement between the rear wheel and the frame, and further causing the jumping track of the rear wheel relative to the frame to be inconsistent under different road conditions, which cannot provide consistent feedback to the driver, thereby reducing the handling performance of the vehicle. Furthermore, the stiffness of the leaf spring changes nonlinearly with the increase of the load, which makes the vehicle prone to bumping when empty and the suspension too hard when fully loaded. SUMMARY

[0003] The purpose of the present application is to overcome the deficiencies in the prior art, and to provide an electric vehicle leaf spring suspension system to improve the consistency of rear wheel jumping and improve the handling performance of the vehicle.

[0004] Technical scheme: In order to achieve the above-mentioned purpose, the electric vehicle leaf spring suspension system of the present application comprises a vehicle body, the bottom of the vehicle body comprises a chassis frame, a rear wheel and a leaf spring suspension; the rear wheel shaft of the rear wheel is connected with the chassis frame through the leaf spring suspension;

[0005] The leaf spring suspension comprises a leaf spring frame, the lower side of the leaf spring frame is provided with a lower convex circular arc-shaped leaf spring assembly, the rear wheel shaft is below the middle part of the leaf spring assembly, and the rear wheel shaft is connected with the lower side of the middle part of the upper leaf spring assembly through a detachable connecting assembly;

[0006] The lower front of the leaf spring assembly is provided with an oblique wheel shaft jumping constraint swing rod, which is in a high front and low rear posture in the initial state; the front end of the wheel shaft jumping constraint swing rod is hinged to the chassis frame through a hinge a, and the rear end of the wheel shaft jumping constraint swing rod is hinged to the rear wheel shaft through a hinge b.

[0007] Further, the lower sides of the front and rear parts of the leaf spring frame are respectively fixed with a front support and a rear support, and the two ends of the leaf spring assembly are respectively connected with the front support and the rear support through inclined front and rear connecting arms.

[0008] Further, the upper end of the front connecting arm is fixedly connected with the front support, and the lower end of the front connecting arm is rotatably connected with the front upper end of the leaf spring assembly; the upper end of the rear connecting arm is hingedly connected with the rear support through a hinge c, and the lower end of the rear connecting arm is rotatably connected with the rear end of the leaf spring assembly.

[0009] Further, the leaf spring frame is fixedly connected with the chassis frame.

[0010] Further, the leaf spring frame is formed by a floating guide rail beam, a front plunger cylinder and a rear plunger cylinder, the floating guide rail beam extends in the front-rear direction, one side of the floating guide rail beam is provided with a guide rail extending in the front-rear direction, a sliding block is guidedly arranged in the guide rail, and one side of the sliding block is fixedly connected with the chassis frame through a front connecting block; the front support and the rear support are integrally arranged at the lower sides of the front plunger cylinder and the rear plunger cylinder respectively;

[0011] The upper end of the rear connecting arm is fixedly connected with the rear support, and the lower end of the rear connecting arm is rotatably connected with the rear end of the leaf spring assembly; the upper end of the front connecting arm is hingedly connected with the front support through a d hinge, and the lower end of the front connecting arm is rotatably connected with the front end of the leaf spring assembly.

[0012] Further, the front plunger cylinder and the rear plunger cylinder are respectively arranged at the front and rear sides of the connecting block, and the front plunger cylinder and the rear plunger cylinder both extend in the front-rear direction; one side of the front plunger cylinder and one side of the rear plunger cylinder are both fixedly connected with the floating guide rail beam; and the ends of the front plunger cylinder and the rear plunger cylinder away from each other are closed.

[0013] The front plunger cylinder and the rear plunger cylinder are respectively provided with a front hydraulic piston and a rear hydraulic piston; the sides of the front plunger cylinder and the rear plunger cylinder away from each other are respectively formed with a front hydraulic cylinder cavity and a rear hydraulic cylinder cavity; and the ends of the front hydraulic piston and the rear hydraulic piston close to each other are respectively fixedly connected with the connecting block through a front piston rod and a rear piston rod.

[0014] The inside of the integrated structure formed by the front hydraulic piston, the front piston rod, the connecting block, the rear piston rod and the rear hydraulic piston is provided with a liquid exchange channel penetrating in the length direction; and the front hydraulic cylinder cavity and the rear hydraulic cylinder cavity are communicated with each other through the liquid exchange channel.

[0015] Further, a conical columnar flow control valve core is coaxially arranged in the rear end of the liquid exchange channel, the thin end of the conical columnar flow control valve core faces forward, the thick end of the conical columnar flow control valve core faces backward, and the rear end of the conical columnar flow control valve core is fixedly connected with the rear end of the rear plunger cylinder.

[0016] Further, in the stable state of the vehicle body under no load, an annular flow-limiting gap is formed between the outer circumferential wall of the conical columnar flow control valve core and the inner wall of the rear end of the liquid exchange channel; and when the conical columnar flow control valve core is displaced backward relative to the rear hydraulic piston, the gap width of the annular flow-limiting gap gradually increases.

[0017] Beneficial effects: When the rear wheel jumps up and down due to bumping, the leaf spring assembly provides jump resistance and buffering, and the axle jump constraint swing rod swings up and down around the a hinge adaptively under the jump action of the rear wheel, which in turn strictly restricts the jump trajectory of the rear wheel and the rear axle during the process of the axle jump constraint swing rod swinging up and down around the a hinge, so that the jump trajectory of the rear wheel under any working condition is consistent, thereby improving the consistency of the rear wheel jump and improving the vehicle handling performance.

[0018] Meanwhile, the second embodiment not only solves the problem of abnormal deformation of the leaf spring assembly, but also improves the problems of being too soft under no-load and too stiff under full load. Attached Figure Description

[0019] Figure 1 A 3D view of the vehicle itself;

[0020] Figure 2 This is a front view of the vehicle body;

[0021] Figure 3 This is a schematic diagram of the suspension three-dimensional structure of the first embodiment;

[0022] Figure 4 This is a front view of the suspension according to the first embodiment;

[0023] Figure 5 for Figure 4 The structural diagram behind the rear wheel has been omitted from the original design.

[0024] Figure 6 This is a front view of the suspension in the second embodiment;

[0025] Figure 7 This is a perspective view of the suspension in the second embodiment;

[0026] Figure 8 for Figure 7 A three-dimensional sectional view. Detailed Implementation

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] As attached Figures 1 to 8 The diagram illustrates a leaf spring suspension system for electric vehicles, applicable to four-wheeled electric vehicles or electric cars. The basic structure includes a vehicle body 1, with a chassis frame 4, a rear wheel 2, and a leaf spring suspension at the bottom of the vehicle body 1. The rear wheel axle 8 of the rear wheel 2 is connected to the chassis frame 4 via the leaf spring suspension. The leaf spring suspension includes a leaf spring frame 11, with a convex arc-shaped leaf spring assembly 6 on the lower side of the leaf spring frame 11. The rear wheel axle 8 is located below the middle of the leaf spring assembly 6, and the rear wheel axle 8 is connected to the lower middle side of the upper leaf spring assembly 6 via a detachable connecting assembly 9. The rear wheel 2 and the rear wheel axle 8 are rotatably connected. This solution can be a front-wheel drive system, where the rear wheel does not provide power.

[0029] Since the leaf spring assembly 6 is a non-rigidly constrained elastic component, the rear wheel will be subjected to pulse-like forces in the front-rear direction under different bumpy road conditions. Due to these forces, the rear wheel will experience a relative offset between itself and the frame, resulting in inconsistent bouncing trajectories of the rear wheel 2 relative to the frame under different road conditions. This lack of consistent feedback to the driver reduces vehicle handling. To optimize this issue, the following optimization solution is provided:

[0030] The plate spring assembly 6 is provided with a slanting wheel shaft bounce constraint swing rod 3 in front and below, which is in a posture of high front and low back in the initial state; the front end of the wheel shaft bounce constraint swing rod 3 is hinged to the chassis frame 4 through an a hinge 5, and the rear end of the wheel shaft bounce constraint swing rod 3 is hinged to the rear wheel shaft 8 through a b hinge 7; the lower sides of the front and rear parts of the plate spring frame 11 are respectively fixed with a front support 12 and a rear support 13, and the two ends of the plate spring assembly 6 are connected to the front support 12 and the rear support 13 through inclined front connecting arms 10 and rear connecting arms 14 respectively. When the rear wheel 2 jumps up and down due to bumping, the plate spring assembly 6 provides bounce resistance and buffering, and the wheel shaft bounce constraint swing rod 3 swings up and down adaptively around the a hinge 5 under the action of the bounce of the rear wheel 2, which in turn strictly constrains the bounce trajectory of the rear wheel 2 and the rear wheel shaft 8 in the process of swinging up and down around the a hinge 5, so that the bounce trajectory of the rear wheel in any working condition remains consistent, thereby improving the consistency of the rear wheel bounce and the vehicle handling performance.

[0031] The plate spring assembly 6 includes "normal elastic deformation" and "abnormal elastic deformation". In the "normal elastic deformation", the plate spring assembly 6 deforms uniformly in curvature radius, the front and rear symmetrical two parts of the plate spring assembly 6 deform symmetrically, the stress changes uniformly at each part of the plate spring assembly 6, and the two sides of the plate spring assembly 6 contract and dilate symmetrically; otherwise, it is "abnormal elastic deformation". In the process of strictly constraining the bounce trajectory of the rear wheel 2 and the rear wheel shaft 8 by the wheel shaft bounce constraint swing rod 3, the lowermost end of the plate spring assembly 6 is forced to strictly follow the swing path displacement of the wheel shaft bounce constraint swing rod 3, which easily leads to the problem of "abnormal elastic deformation" of the plate spring assembly 6. The non-coincident trajectories need to be bridged by irregular deformation of the plate spring assembly 6, thereby affecting the service life of the plate spring. Therefore, on the basis of the above structure, the following two further optimized embodiments are provided.

[0032] The first embodiment (as Figure 3 、 4 、5):

[0033] The upper end of the front connecting arm 10 is fixedly connected to the front support 12, and the lower end of the front connecting arm 10 is rotationally connected to the front upper end of the plate spring assembly 6; the upper end of the rear connecting arm 14 is hinged to the rear support 13 through a c hinge 14a, and the lower end of the rear connecting arm 14 is rotationally connected to the rear end of the plate spring assembly 6; the plate spring frame 11 is fixedly connected to the chassis frame 4;

[0034] When the rear wheel 2 and the rear axle 8 jump upward, the lower end of the leaf spring assembly 6 moves upward, and the leaf spring assembly 6 performs a relaxation elastic deformation with gradually increasing radius of curvature. Since the front connecting arm 10 is fixed, the relaxation elastic deformation of the leaf spring assembly 6 with gradually increasing radius of curvature will make the rear connecting arm 14 swing backward around the c hinge 14a, so that the lowermost end of the leaf spring assembly 6 is displaced upward and also deviates backward, and further tends to be consistent with the movement path of the b hinge 7 end of the axle jump constraint swing rod 3, so that the leaf spring assembly 6 is as symmetrical as possible in front and back, thereby reducing the movement interference between the leaf spring assembly 6 and the axle jump constraint swing rod 3 and reducing the degree of “abnormal elastic deformation” of the leaf spring assembly 6. However, the movement interference cannot be completely avoided, and thus the “abnormal elastic deformation” cannot be completely eliminated. Therefore, the second embodiment described below is additionally designed.

[0035] The second embodiment (as Figure 6 、 7 , 8):

[0036] The leaf spring frame 11 is integrally formed by the floating guide rail beam 11c, the front plunger barrel 11a and the rear plunger barrel 11b. The floating guide rail beam 11c extends in the front-rear direction. The floating guide rail beam 11c is provided with a guide rail 21 extending in the front-rear direction on one side. The guide rail 21 is provided with a sliding block 20 guided therein. One side of the sliding block 20 is fixedly connected to the chassis frame 4 through the inner connecting block 18. The front support 12 and the rear support 13 are integrally arranged on the lower side of the front plunger barrel 11a and the rear plunger barrel 11b respectively. The upper end of the rear connecting arm 14 is fixedly connected to the rear support 13, and the lower end of the rear connecting arm 14 is rotatably connected to the rear end of the leaf spring assembly 6. The upper end of the front connecting arm 10 is hingedly connected to the front support 12 through the d hinge 10a, and the lower end of the front connecting arm 10 is rotatably connected to the front end of the leaf spring assembly 6.

[0037] Since the axle jump constraint swing rod 3 is an inclined structure, when the rear wheel 2 jumps upward due to bumping, the lower end of the leaf spring assembly 6 moves upward, and the leaf spring assembly 6 performs a relaxation elastic deformation with gradually increasing radius of curvature. Since the rear connecting arm 14 is fixed, the relaxation elastic deformation of the leaf spring assembly 6 with gradually increasing radius of curvature will make the front connecting arm 10 swing forward around the d hinge 10a, so that the lowermost end of the leaf spring assembly 6 is displaced upward and also deviates forward. At the same time, the axle jump constraint swing rod 3 swings upward around the a hinge 5. Under the forced constraint of the axle jump constraint swing rod 3, the rear wheel 2 will also deviate backward during the upward jumping process.

[0038] The upward displacement of the lowermost end of the leaf spring assembly 6 and the rearward displacement during the upward jump of the rear wheel 2 generate stronger "front-rear direction motion interference", but in the present scheme, the leaf spring bracket 11 can freely float horizontally, specifically, the leaf spring bracket 11 composed of the floating guide rail beam 11c, the front plunger barrel 11a and the rear plunger barrel 11b automatically adaptively offset rearward under the guidance of the sliding block 20 and the guide rail 21, thereby eliminating the above-mentioned "front-rear direction motion interference", thereby effectively alleviating the problem of "abnormal elastic deformation" of the leaf spring assembly 6.

[0039] The following is a further optimized structure based on the "second embodiment":

[0040] As shown in Figure 7 and 8 , the front plunger barrel 11a and the rear plunger barrel 11b are respectively on the front and rear sides of the connecting block 18, and the front plunger barrel 11a and the rear plunger barrel 11b both extend in the front-rear direction, one side of the front plunger barrel 11a and the rear plunger barrel 11b is fixedly connected with the floating guide rail beam 11c; the ends of the front plunger barrel 11a and the rear plunger barrel 11b away from each other are closed; the front plunger barrel 11a and the rear plunger barrel 11b are respectively provided with a front hydraulic piston 30a and a rear hydraulic piston 30b; the sides of the front plunger barrel 11a and the rear plunger barrel 11b away from each other respectively form a front hydraulic cylinder cavity 23a and a rear hydraulic cylinder cavity 23b; the ends of the front hydraulic piston 30a and the rear hydraulic piston 30b close to each other are respectively fixedly connected with the connecting block 18 through a front piston rod 17a and a rear piston rod 17b; the inside of the integrated structure composed of the front hydraulic piston 30a, the front piston rod 17a, the connecting block 18, the rear piston rod 17b and the rear hydraulic piston 30b is provided with a liquid exchange channel 22 penetrating along the length direction, the front hydraulic cylinder cavity 23a and the rear hydraulic cylinder cavity 23b are communicated with each other through the liquid exchange channel 22; the rear end of the liquid exchange channel 22 is coaxially provided with a conical columnar flow control valve core 26, the thin end of the conical columnar flow control valve core 26 faces forward, the thick end faces rearward, and the rear end of the conical columnar flow control valve core 26 is fixedly connected with the rear end integral cover 70 of the rear plunger barrel 11b, and the front hydraulic cylinder cavity 23a, the rear hydraulic cylinder cavity 23b and the liquid exchange channel 22 are all filled with hydraulic oil.

[0041] From the structure, during the upward jump of the rear wheel 2, the leaf spring bracket 11 composed of the floating guide rail beam 11c, the front plunger barrel 11a and the rear plunger barrel 11b is offset forward or rearward relative to the chassis bracket 4 under the guidance of the sliding block 20 and the guide rail 21, thereby enabling the front hydraulic cylinder cavity 23a and the rear hydraulic cylinder cavity 23b to exchange liquid through the liquid exchange channel 22;

[0042] In the empty state of the vehicle body 1, the annular flow-limiting gap 25 is formed between the outer wall of the conical-cylindrical flow control valve core 26 and the inner wall of the rear end of the liquid exchange channel 22. In the empty state of the vehicle, the annular flow-limiting gap 25 is relatively narrow, thereby effectively limiting the flow of the liquid exchange channel 22, thereby forming resistance to the forward or backward deflection of the leaf spring assembly 11 composed of the floating guide rail beam 11c, the front plunger cylinder 11a and the rear plunger cylinder 11b relative to the chassis frame 4, thereby achieving the effect of suppressing the bounce of the rear wheel in the empty state.

[0043] When the vehicle is in a full load state, the rear wheel 2 is subjected to a larger load, the curvature radius of the leaf spring assembly 6 becomes larger, the axle bump constraint swing rod 3 swings upward by a certain distance around the hinge 5, and the leaf spring assembly 11 composed of the floating guide rail beam 11c, the front plunger cylinder 11a and the rear plunger cylinder 11b is automatically deflected backward by a certain distance relative to the "empty state" under the guidance of the slider 20 and the guide rail 21, so that the conical-cylindrical flow control valve core 26 is displaced backward relative to the rear hydraulic piston 30b, and the gap width of the annular flow-limiting gap 25 is relatively larger than that in the "empty state". Thus, the liquid in the liquid exchange channel 22 flows more smoothly, and the flow restriction in the liquid exchange channel 22 is relatively removed, thereby achieving the effect of removing the bounce suppression of the rear wheel in the empty state, and avoiding the problem of over-hard suspension under full load.

[0044] Furthermore, the problem of over-soft in the empty state and over-hard in the full load state is finally improved.

[0045] The above is only a preferred embodiment of the present application, and it should be noted that for ordinary skilled persons in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An electrically powered scooter leaf spring suspension system characterized by: The application relates to a vehicle body (1) comprising a chassis frame (4), rear wheels (2) and a leaf spring suspension; the rear wheel shaft (8) of the rear wheels (2) is connected with the chassis frame (4) through the leaf spring suspension; The leaf spring suspension comprises a leaf spring frame (11) provided with a lower convex circular arc-shaped leaf spring assembly (6) at the lower side, the rear wheel shaft (8) is below the middle part of the leaf spring assembly (6), and the rear wheel shaft (8) is connected with the lower side of the middle part of the upper leaf spring assembly (6) through a detachable connecting assembly (9); The front lower part of the leaf spring assembly (6) is provided with an oblique wheel shaft jump constraint swing rod (3), the oblique wheel shaft jump constraint swing rod (3) is in a front-high rear-low posture in the initial state; the front end of the wheel shaft jump constraint swing rod (3) is hinged to the chassis frame (4) through an a hinge (5), and the rear end of the wheel shaft jump constraint swing rod (3) is hinged to the rear wheel shaft (8) through a b hinge (7); The lower sides of the front and rear parts of the leaf spring frame (11) are respectively fixed with a front support (12) and a rear support (13), and the two ends of the leaf spring assembly (6) are connected with the front support (12) and the rear support (13) through inclined front connecting arms (10) and rear connecting arms (14); The leaf spring frame (11) is integrally formed by a floating guide rail beam (11c), a front plunger cylinder (11a) and a rear plunger cylinder (11b), the floating guide rail beam (11c) extends in the front-rear direction, one side of the floating guide rail beam (11c) is provided with a guide rail (21) extending in the front-rear direction, a sliding block (20) is arranged in the guide rail (21), and one side of the sliding block (20) is fixedly connected with the chassis frame (4) through a connecting block (18); the front support (12) and the rear support (13) are integrally arranged at the lower sides of the front plunger cylinder (11a) and the rear plunger cylinder (11b) respectively; The upper end of the rear connecting arm (14) is fixedly connected with the rear support (13), and the lower end of the rear connecting arm (14) is rotatably connected with the rear end of the leaf spring assembly (6); the upper end of the front connecting arm (10) is hinged to the front support (12) through a d hinge (10a), and the lower end of the front connecting arm (10) is rotatably connected with the front end of the leaf spring assembly (6); The front plunger cylinder (11a) and the rear plunger cylinder (11b) are respectively arranged at the front and rear sides of the connecting block (18), and the front plunger cylinder (11a) and the rear plunger cylinder (11b) both extend in the front-rear direction; one side of the front plunger cylinder (11a) and the rear plunger cylinder (11b) is fixedly connected with the floating guide rail beam (11c); and the ends of the front plunger cylinder (11a) and the rear plunger cylinder (11b) away from each other are closed; Front and rear hydraulic pistons (30a) and (30b) are arranged in the front plunger cylinder (11a) and the rear plunger cylinder (11b) respectively; the side of the front plunger cylinder (11a) and the rear plunger cylinder (11b) away from each other forms front and rear hydraulic cylinder cavities (23a) and (23b) respectively; and the ends of the front and rear hydraulic pistons (30a) and (30b) close to each other are fixedly connected with the connecting block (18) through front and rear piston rods (17a) and (17b) respectively. The inside of the integrated structure of the front hydraulic piston (30a), the front piston rod (17a), the connecting block (18), the rear piston rod (17b) and the rear hydraulic piston (30b) is provided with a liquid exchange channel (22) penetrating along the length direction, and the front hydraulic cylinder cavity (23a) and the rear hydraulic cylinder cavity (23b) are communicated with each other through the liquid exchange channel (22); A conical cylindrical flow control valve core (26) is coaxially arranged in the rear end of the liquid exchange channel (22), the thin end of the conical cylindrical flow control valve core (26) faces forward, the thick end faces backward, and the rear end of the conical cylindrical flow control valve core (26) is fixedly connected with the rear end integral cover (70) of the rear piston cylinder (11b).

2. An electrically powered board spring suspension system as claimed in claim 1 wherein: The leaf spring frame (11) is fixedly connected with the chassis frame (4).

3. An electrically powered board spring suspension system as claimed in claim 2 wherein: In the empty load stable state of the vehicle body (1), an annular flow-limiting gap (25) is formed between the outer peripheral wall of the conical cylindrical flow control valve core (26) and the inner wall of the rear end of the liquid exchange channel (22), and when the conical cylindrical flow control valve core (26) is displaced backward relative to the rear hydraulic piston (30b), the gap width of the annular flow-limiting gap (25) gradually increases.

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