CN209634203U - A kind of distributed driving chassis platform for realizing four-wheel independent steering - Google Patents

Abstract

The utility model discloses a distributed drive chassis platform for realizing four-wheel independent steering. A suspension mechanism is installed between the body frame and the four wheel assemblies at the four corners. Each suspension mechanism includes a special-shaped horn, an upper cross arm, an electric push rod assembly and a lower swing arm. The special-shaped horn is located above the wheel assembly. , the lower end of the special-shaped horn is connected to the wheel assembly, the middle and upper parts of the special-shaped horn are connected to the body frame through the lower swing arm and the upper cross arm respectively, and the middle part of the special-shaped horn is connected to the output end of one side of the EPS steering gear assembly through the electric push rod assembly. One end of the transverse leaf spring assembly is connected to the upper wishbone. The utility model has a specially designed suspension system. The chassis platform supports four-wheel independent drive and four-wheel independent steering, and realizes the vehicle's in-situ steering, horizontal lateral movement and parking functions. Large angle, reliable structure and performance, and strong expandability.

Description

A Distributed Drive Chassis Platform Realizing Four-Wheel Independent Steering

technical field

The utility model relates to the field of new energy vehicles, in particular to a new energy vehicle suspension and steering system, in particular to a distributed drive chassis platform for realizing four-wheel independent steering.

Background technique

At present, with the rapid development of new energy vehicles, many pure electric vehicles of different brands have appeared in China. But the main thing is to directly replace the engine with the central motor, and the structure and transmission mode of the whole vehicle have not been changed. At the same time, the traditional suspension method and steering mechanism are used, and each wheel cannot be turned independently. The turning radius of the vehicle is large, and it is very difficult to turn and turn around in a narrow area.

With the development of in-wheel motor technology, a new energy vehicle with distributed drive has emerged. How to reasonably design the suspension and steering system, effectively integrate the hub motor with the suspension and steering mechanism, increase the wheel steering angle, reduce the turning radius of the vehicle, and improve the flexibility of vehicle control have become urgent problems to be solved.

Utility model content

In order to solve the problems existing in the background technology, the technical problem to be solved by the utility model is to propose a distributed drive chassis platform for four-wheel independent steering, in which a suspension system with a special structural design is adopted, and the vehicle can realize In-situ U-turn, horizontal traversing functions, realize ultra-small turning radius when turning.

The utility model supports four-wheel independent drive and four-wheel independent steering, these functions can be operated through the vehicle control system, and the vehicle automatically realizes the above-mentioned special functions.

In order to realize the above-mentioned vehicle intelligent control system, the core technical scheme adopted by the utility model is specifically as follows:

The utility model comprises a body frame, four suspension mechanisms, and an EPS steering gear assembly and a horizontal leaf spring assembly installed between two wheel assemblies on both sides of the front and rear of the body frame. A suspension mechanism is installed between each wheel assembly, and each suspension mechanism includes a special-shaped horn, an upper cross arm, an electric push rod assembly and a lower swing arm. The special-shaped horn is located above the wheel assembly, and the lower end of the special-shaped horn is connected to the wheel assembly. The middle and upper parts of the special-shaped horns are connected to the body frame through the lower swing arm and the upper cross arm respectively, the middle part of the special-shaped horns is connected to the output end of one side of the EPS steering gear assembly through the electric push rod assembly, and the horizontal leaf spring assembly One end is connected to the upper wishbone.

The upper cross arm is mainly assembled by a cylindrical pin ball head, a swing arm main body, and two upper arm bushes. The main body of the swing arm is in the shape of a herringbone. Ball hinge connection, the two bifurcated ends of the herringbone main body of the swing arm are articulated through the upper arm bushing and the top of the body frame by single-axis rotation; the lower swing arm is mainly composed of a fisheye ball head, a welded pipe main body and two lower arm linings The main body of the welded pipe is herringbone-shaped. The herringbone-shaped collection end of the welded pipe main body is connected by a fish-eye ball head and a ball joint in the middle of the special-shaped horn. It is hinged with the middle part of the body frame by single-axis rotation; the cylindrical pin ball head of the upper cross arm is located directly above the fisheye ball head of the lower swing arm, and the center connection line between the straight pin ball head and the fisheye ball head is used as a virtual kingpin , the virtual kingpin passes through the wheel center of the wheel assembly; in the utility model, the virtual kingpin passes through the structure of the wheel center of the wheel assembly, compared with existing suspension structures such as MacPherson suspensions that do not pass through the wheel The core structure, the structure is symmetrical and stable, and can better support and stabilize.

The electric push rod assembly is mainly assembled from the electric push rod main body, displacement sensor, thread conversion sleeve, and taper pin ball head. The displacement sensor is fixedly connected to the electric push rod main body through the displacement sensor mounting bracket. The probe rod and the push rod of the main body of the electric push rod are arranged in parallel, and are affixed to each other through a displacement sensor driving bracket. The other end is installed with the ball head of the cone pin, which is hinged on the L-shaped bracket provided on the side of the special-shaped horn; catch;

The horizontal leaf spring assembly is mainly composed of leaf springs and hanger brackets. The two sides of the middle part of the leaf spring are horizontally fixed on the body frame through two leaf spring body fixing brackets. The ends of the leaf spring It is a mounting bracket at the end of the leaf spring, and the mounting bracket at the end of the leaf spring is hinged through the lifting lug bracket and the swing arm main body of the upper cross arm.

The upper cross arm is supported by the transverse leaf spring assembly, thereby bearing the bumps and jumps of the wheel assembly.

One end of the lifting lug bracket is hinged to the mounting bracket at the end of the leaf spring, and the other end of the lifting lug bracket is hinged to the middle part of the herringbone of the main body of the swing arm.

The EPS steering gear assembly is mainly composed of a rack and pinion steering gear, a universal joint, and an EPS driving motor. The EPS driving motor is fixed on the body frame, and the output shaft of the EPS driving motor is steered through the universal joint and the rack and pinion. The input end of the machine is connected to the output end of the rack and pinion steering machine.

The special-shaped horn is assembled and connected by a plurality of split brackets, and is divided into three Z-shaped sections. The lower end of the upper section and the upper end of the lower section are connected by a horizontal section, and the upper section and the lower section are vertical and perpendicular to the horizontal section. , the lower section is located on the inner side of the wheel assembly and connected to the wheel assembly, and the upper section is located above the wheel assembly after being bent by the horizontal section.

The wheel assembly is mainly composed of tires, rims and hub motors. The tires are installed outside the rim, and the hub motor is installed in the center of the rim. The stator part of the hub motor is connected to the bottom end of the special-shaped horn.

The transverse leaf spring assembly is replaced by a columnar shock absorber, which is connected between the vehicle body frame and the upper cross arm.

The utility model has two steering control approaches, one is steering control through the EPS steering gear assembly, the other is steering control through the electric push rod main body, and the front and rear two controls are carried out independently, respectively for the driving state and the stopping state of the car. , do not exist simultaneously. That is, when the EPS steering gear assembly is working, the main body of the electric push rod is fixed and locked and does not work; when the main body of the electric push rod is working, the EPS steering gear assembly is fixed and locked and does not work.

When the car is running, the two wheel assemblies on both sides of the front/rear of the body frame jointly perform synchronous steering control through an EPS steering gear assembly, which can realize the steering of the car.

When the car is stopped and not driving, each wheel assembly performs steering control through its own electric push rod main body, which can realize the car's in-situ steering and reversing translational driving.

The specially designed suspension system of the utility model is installed on the automobile, which can realize the steering of the automobile on the spot, facilitate parking and storage, greatly facilitate the parking method, and help to improve the utilization rate of the parking space.

Under the suspension system of the utility model, the driver also adopts the control mode of a conventional vehicle to drive the vehicle, holding the steering wheel, pedaling the brake pedal and the accelerator pedal. Among them, the intelligent control system and the manual control system are integrated solutions. According to the needs of the driver, the driver can actively switch between the two systems to realize the control of the whole vehicle.

The specially designed suspension system of the utility model is installed on the car, which can realize the in-situ steering, horizontal lateral movement and parking of the car, which is convenient for parking and storage, greatly facilitates the parking method, and can help to improve the utilization of parking space Rate.

The beneficial effects brought by the technical solution provided by the utility model are:

1. The traditional suspension, steering and transmission mechanism integration scheme can realize the wheel toe angle in the range of -45° to 35°, and the self-developed virtual kingpin suspension system that passes through the wheel center can realize the wheel toe angle - Steering angles from 90° to 35°.

2. The traditional suspension, steering and transmission mechanism integration scheme realizes the linkage between the left and right wheels through a steering gear. The self-developed virtual kingpin suspension system that passes through the wheel center not only has the traditional steering function, but also the traditional steering function. Based on the innovative design of the single-wheel steering independent control system, the EPS steering gear assembly 31 control system supports traditional steering functions; the electric push rod assembly 6 control system supports special steering functions, and the two control systems are integrated under one suspension system , controlled by the vehicle controller, the two systems do not interfere with each other, and the structure and performance are reliable.

3. The design of the virtual kingpin in the traditional suspension scheme leads to the inconsistency of the inner and outer wear states of the wheels. Commonly, the outer side is severely worn and the inner side is slightly worn, which reduces the service life of the tire and affects driving safety. The self-developed virtual kingpin suspension system passing through the wheel center is structurally designed to pass the extension line of the virtual kingpin through the center point of the wheel, thus reducing the steering friction of the wheel and lowering the EPS steering gear assembly 31 and electric thrust. The power output of the rod assembly 6 and the stress on the parts save energy and prolong the service life of the parts. At the same time, the wear state of the inside and outside of the tire is almost consistent, prolonging the service life of the tire.

4. The structure of the virtual kingpin suspension system independently developed by this utility model that passes through the center of the wheel and the matching interface structure of the special-shaped horn and the distributed drive motor can support the matching of various types of motors. The chassis platform has a strong ability to expand and reduce The basic research and development costs of platform models with different power requirements.

5. The virtual kingpin suspension system independently developed by the utility model through the wheel center can realize the steering function of four special modes.

Description of drawings

Figure 1 is a schematic diagram of the structure of the suspension system.

FIG. 2 is a schematic diagram of a partially enlarged structure of FIG. 1 .

Fig. 3 is a schematic diagram of the structure of the special-shaped horn.

Fig. 4 is a structural schematic diagram of the upper cross arm.

Fig. 5 is a structural schematic diagram of the transverse leaf spring assembly.

Fig. 6 is a schematic structural view of the electric push rod assembly.

Fig. 7 is a schematic diagram of the structure of the lower swing arm.

Fig. 8 is a structural schematic diagram of the wheel assembly.

Fig. 9 is a 90-degree corner state diagram of a single wheel under the suspension system of the present invention.

Fig. 10 is a structural schematic diagram of the EPS steering gear assembly.

Fig. 11 is a schematic structural diagram of the chassis platform formed by the suspension system.

Fig. 12 is a working state diagram of normal steering mode.

Fig. 13 is a diagram of the working state of the spot steering mode.

Fig. 14 is a working state diagram of the horizontal movement mode.

Fig. 15 is a working state diagram of the parking mode.

In the figure: 1. Special-shaped horns, 3. Upper cross arm, 4. Body frame, 5. Horizontal leaf spring assembly, 6. Electric push rod assembly, 7. Lower swing arm, 8. Wheel assembly, 9. Virtual King pin (rotation center line formed by the connection of the upper and lower swing arm ball points); 10. Cylindrical pin ball joint, 11. Swing arm main body, 12. Upper arm bushing; 13. Lifting lug bracket, 14. Steel plate Spring, 15, leaf spring body fixing bracket, 16, leaf spring end mounting bracket; 17, thread conversion bracket, 18, electric push rod main body, 19, displacement sensor, 20, displacement sensor mounting bracket, 21, thread conversion sleeve, 22 , displacement sensor drive bracket, 23, thread conversion sleeve, 24, cone pin ball head; 25, fisheye ball head, 26, welded pipe main body, 27, lower arm bushing; 28, tire, 29, rim, 30. Hub motor; 31. EPS steering gear assembly; 32. Rack and pinion steering gear; 33. Universal joint; 34. EPS drive motor.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail.

In a specific implementation, the chassis platform includes a body frame 4, four suspension mechanisms, and an EPS steering gear assembly 31 and a transverse leaf spring installed between the two wheel assemblies 8 on both sides of the front/rear of the body frame 4. Assembly 5, a suspension mechanism is installed between the body frame 4 and the four wheel assemblies 8 at the four corners respectively.

As shown in Figures 1 and 2, each suspension mechanism includes a special-shaped horn 1, an upper cross arm 3, an electric push rod assembly 6 and a lower swing arm 7, the special-shaped horn 1 is located above the wheel assembly 8, and the lower end of the special-shaped horn 1 is connected to The stator part of the wheel hub motor of the wheel assembly 8, the special-shaped horn 1 and the wheel assembly 8 rotate around the virtual kingpin 9, the wheel assembly 8 rotates around the axis of its own motor, and the rotating part is the hub motor rotor and the rotor fixedly connected with the rotor The middle and upper parts of the special-shaped horn 1 of the rim and tire are connected to the body frame 4 in parallel via the lower swing arm 7 and the upper cross arm 3 respectively, and the middle part of the special-shaped horn 1 is connected to the output end of one side of the EPS steering gear assembly 31 through the electric push rod assembly 6 One side end of the transverse leaf spring assembly 5 is connected to the upper cross arm 3 . Specifically as shown in Figure 1, the special-shaped croissant 1 middle part is hinged by a ball at one end of the lower swing arm 7, the other end of the lower swing arm 7 is hinged with the body frame 4 rotating shafts, the top of the special-shaped croissant 1 is articulated by a ball at one end of the upper cross arm 3, and the upper cross arm 3 is the other. One end is hinged with 4 rotating shafts of the body frame.

As shown in FIG. 3 , the special-shaped horn 1 is assembled and connected by a plurality of split brackets, and is in a vertically extending Z shape. Divided into three Z-shaped sections, the lower end of the upper section and the upper end of the lower section are connected by a horizontal section, the upper section and the lower section are vertical and perpendicular to the horizontal section, and the lower section is located inside the wheel assembly 8 and connected to the wheel assembly 8. The upper section is positioned above the wheel assembly 8 after the horizontal section is bent.

As shown in Figure 4, the upper cross arm 3 is mainly assembled by a cylindrical pin ball head 10, a swing arm body 11, and two upper arm bushes 12. The swing arm body 11 is herringbone-shaped, and the collection end of the swing arm body 11 is herringbone The ball head 10 of the cylindrical pin is connected with the upper ball joint of the special-shaped horn 1, and the two bifurcated ends of the herringbone of the swing arm main body 11 are hinged by the upper arm bushing 12 and the top of the body frame 4 by uniaxial rotation; the top of the body frame 4 is provided with a The horizontal hinge shaft of the direction/traveling direction, the two bifurcated ends of the swing arm main body 11 herringbone are hinged to the horizontal hinge shaft through the upper arm bushing 12 .

As shown in Figure 7, the lower swing arm 7 is mainly assembled by a fisheye ball head 25, a welded pipe main body 26 and two lower arm bushings 27. The herringbone assembly end of the main body 26 of the welded pipe is connected by the fish-eye ball head 25 and the ball joint in the middle of the special-shaped horn 1, and the two forked ends of the main body 26 of the welded pipe are connected by the lower arm bushing 27 and the body frame. 4. The middle part is uniaxially hinged; the middle part of the body frame 4 is provided with a horizontal hinge shaft along the direction of the vehicle body/traveling direction, and the two bifurcated ends of the welded pipe main body 26 herringbone are hinged to the horizontal hinge shaft through the lower arm bushing 27.

In specific implementation, as shown in FIG. 3 , a lug structure is provided in the middle of the special-shaped horn 1 , and the herringbone-shaped collective end of the welded pipe body 26 is connected to the lug structure through a fish-eye ball head 25 . The straight pin ball head 10 of the upper cross arm 3 is located directly above the fisheye ball head 25 of the lower swing arm 7, and the center connection line between the straight pin ball head 10 and the fisheye ball head 25 is used as the virtual kingpin 9, and the virtual kingpin 9 Pass through the wheel center of the wheel assembly 8.

As shown in Figure 6, the electric push rod assembly 6 is mainly assembled by the electric push rod main body 18, displacement sensor 19, thread conversion sleeve 23, and taper pin ball head 24, and the displacement sensor 19 is fixed by the displacement sensor mounting bracket 20 Connected to the electric push rod main body 18, the probe rod of the displacement sensor 19 and the push rod of the electric push rod main body 18 are arranged in parallel, and are fixedly connected by the displacement sensor driving bracket 22, and the push rod output port of the electric push rod main body 18 is provided with The thread conversion sleeve 21, the push rod end of the electric push rod main body 18 stretches out from the thread conversion sleeve 21 and is fixedly connected with one end of the thread conversion sleeve 23, and the other end of the thread conversion sleeve 23 is installed with a tapered surface pin ball head 24, and the cone The face pin ball head 24 is threaded into the threaded hole at the other end of the thread conversion sleeve 23; the side of the special-shaped horn 1 is provided with an L-shaped bracket, and the ball joint 24 of the tapered surface pin is provided with an L-shaped bracket on the side of the special-shaped horn 1. On the bracket; the opposite end of the push rod end of the electric push rod main body 18 is affixed to one of the output ends at the two ends of the rack and pinion steering machine 32 of the EPS steering gear assembly 31 through the thread conversion bracket 17 .

The main body 18 of the electric push rod runs, and the extension and contraction of the push rod end drives the thread conversion sleeve 23 and the probe rod of the displacement sensor 19 to move, and the thread conversion sleeve 23 moves through the cone pin ball head 24 to push the special-shaped horn 1 to rotate around the virtual kingpin 9, And then realize the turning of wheel assembly 8. Further, the wheel assemblies 8 on both sides of the body frame 4 are respectively controlled by the electric push rod main body 18 corresponding to the suspension mechanism to realize different steering and asynchronous steering of the wheel assemblies 8 on both sides of the body frame 4 .

As shown in Figure 5, the horizontal leaf spring assembly 5 is mainly assembled by a leaf spring 14 and a hanger bracket 13, and the two sides of the middle part of the leaf spring 14 are horizontally fixed to the body frame by two leaf spring body fixing brackets 15. 4, the end of the leaf spring 14 is the end mounting bracket 16 of the leaf spring, and the end mounting bracket 16 of the leaf spring is hinged to the swing arm main body 11 of the upper cross arm 3 through the lug bracket 13. One end of the lug bracket 13 is hinged to the mounting bracket 16 at the end of the leaf spring, and the other end of the lug bracket 13 is hinged to the herringbone middle part of the swing arm main body 11 .

In specific implementation, the transverse leaf spring assembly 5 is further replaced by a columnar shock absorber, which includes a coil spring and a shock absorber, and the columnar shock absorber is connected between the body frame 4 and the upper cross arm 3 . When the wheels are impacted and bounced in the direction perpendicular to the road surface, the transverse leaf spring as an elastic element can effectively play a buffering role, but it does not have a shock-absorbing effect by itself and occupies a large lateral space. The coil spring in the columnar shock absorber can be used as an elastic element to realize the function of a horizontal leaf spring and has a compact structure; at the same time, the shock absorber can suppress the beating of the coil spring, absorb the resulting vibration, and improve the ride comfort of the vehicle. Compared with the horizontal leaf spring structure, the columnar shock absorber can take advantage of a smaller layout space of the vehicle, which not only meets the load requirements of the vehicle, but also effectively suppresses the impact of the road on the body, provides the function of buffering and shock absorption, and improves the overall performance of the vehicle. Driving comfort.

As shown in Figure 10, the EPS steering gear assembly 31 is mainly assembled from a rack and pinion steering gear 32, a universal joint 33, and an EPS driving motor 34. The EPS driving motor 34 is fixed on the body frame 4, and the EPS driving motor 34 outputs The shaft is connected to the input end of the rack and pinion steering machine 32 through the universal joint 33, and the output end of the rack and pinion steering machine 32. The operation of the EPS drive motor 34 drives the rack bar in the rack and pinion steering gear 32 to move horizontally back and forth between the two wheel assemblies 8 on both sides of the vehicle body frame 4, and then through the electric push rod main body 18 (which can be regarded as rigid at this time). bar) promotes the wheel assembly 8 on both sides to turn synchronously.

As shown in Figure 8, the wheel assembly 8 is mainly assembled from tires 28, rims 29 and hub motors 30, tires 28 are installed outside the rims 29, hub motors 30 are installed in the center of the rims 29, and the stator part of the hub motors 30 is fixedly connected to the special-shaped The bottom end of horn 1, the rotor part of hub motor is fixedly connected with wheel rim 29. When the hub motor 30 is running, the rotor is fixedly connected to the rim 29 , and then drives the wheel formed by the rim 29 and the tire 28 to rotate.

The wheel assembly 8 is connected to the vehicle controller to control the torque and speed of each motor in real time through traction control, torque vector control, etc., to ensure the correctness of the motor rotation direction and driving torque in different modes.

The assembly process of each main component in the suspension system of the present utility model is (the left and right sides of the vehicle frame are symmetrical, taking the left side as an example):

1) Insert the cylindrical pin ball head 10 at the herringbone collection end of the upper cross arm 3 into the empty slot hole provided on the top surface of the special-shaped horn 1, and fix and lock the bolt and nut laterally so that the upper cross arm 3 passes through the cylindrical pin ball head 10 is connected with the ball hinge at the upper end of the special-shaped horn 1; the two upper arm bushings 12 at the two bifurcated ends of the herringbone shape of the upper cross arm 3 are installed on the top of the two vertical supports of the vehicle body frame 4, fixed and locked by bolts and nuts, The upper cross arm 3 is pivotally hinged around the horizontal axis through the upper arm bushing 12 and the top of the body frame 4 .

2) Install the fisheye ball head 25 at the herringbone collection end of the lower cross arm 7 in the bracket at the middle position of the special-shaped horn 1, and fix and lock it with bolts and nuts, so that the lower cross arm 7 passes through the fisheye ball head 25 and the middle spherical hinge of the special-shaped horn 1 Connection; install the two lower arm bushings 27 of the two herringbone ends of the lower cross arm 7 on the middle of the two vertical brackets of the body frame 4, and fix and lock the lower cross arm 7 through the lower cross arm 7. The arm bushing 27 and the middle part of the body frame 4 are pivotally hinged around the horizontal axis.

3) Install the two leaf spring body fixing brackets 15 of the leaf spring assembly 5 on the body frame 4, and fix and lock them with bolts and nuts; fix the two lifting lug brackets 13 of the leaf spring assembly 5 on the upper swing arm 3 In the bracket on the main body 11 of the swing arm, it is fixed and locked by bolts and nuts.

4) Install the rack and pinion steering gear 32 of the EPS steering gear assembly 31 on the body frame 4, and fix and lock it with bolts and nuts; install the EPS drive motor 34 of the EPS steering gear assembly 31 on the body frame 4, and The bolts and nuts are fixed and locked.

5) Insert the taper pin ball head 24 of the electric push rod assembly 6 into the installation hole provided by the L-shaped bracket on the side of the special-shaped horn 1, and fix and lock it with nuts; install the thread conversion bracket 17 of the electric push rod assembly 6 On the stud at the end of the rack and pinion steering gear 32, it is fixed and locked by a nut.

As shown in Figure 11, the four wheels at the four corners of the chassis platform are all provided with the suspension system of the present invention, which constitutes a distributed drive chassis platform that realizes four-wheel independent steering. There are two working modes of steering control under the chassis platform, one is steering control through the EPS steering gear assembly 31, and the other is steering control through the electric push rod main body 18. The running state and the stopping state do not exist at the same time. That is, when the EPS steering gear assembly 31 is working, the electric push rod main body 18 is fixed and locked and does not work; when the electric push rod main body 18 is working, the EPS steering gear assembly 31 is fixed and locked and does not work.

When the vehicle is running, the two wheel assemblies 8 on both sides of the front/rear of the vehicle body frame 4 jointly perform synchronous steering control through an EPS steering gear assembly 31, which can realize the steering of the vehicle.

When the vehicle is in a stopped state, each wheel assembly 8 performs steering control through its respective electric push rod main body 18, so that the vehicle's in-situ steering and reversing translational travel can be realized.

The principle process of the two specific working modes of the chassis platform is as follows:

1. When the car is running, the EPS steering gear assembly 31 control system works in the following modes:

The vehicle controller inputs and controls the EPS drive motor 34 to generate a steering assist torque of a determined magnitude and direction, which is transmitted to the universal joint 33, and then the universal joint 33 drives the rack-and-pinion steering gear 32 to make the gear teeth The internal rack mechanism of the bar steering machine 32 realizes horizontal sliding, and the output is driven by the electric push rod assembly 6 to push the special-shaped horn 1 to rotate around the virtual kingpin 9, and then push the two wheel assemblies 8 on both sides of the body frame 4 to move back and forth horizontally . Specifically, the tapered pin ball head 24 of the electric push rod assembly 6 will pull/promote the special-shaped horn 1, and the special-shaped horn 1 rotates around the virtual kingpin 9, and the special-shaped horn 1 drives the wheel assembly to rotate again to realize the wheel steering.

In this working mode, the electric push rod assembly 6 is not working and the electric push rod main body 18 is in a self-locking state, the overall size of the electric push rod assembly 6 will not change, and its current function is a rod with a fixed length .

2. When the car is stopped, the electric push rod assembly 6 control system:

The vehicle controller inputs to control the electric push rod main body 18, and the motor inside the electric push rod main body 18 will drive the push rod of the electric push rod main body 18 to extend or retract, so as to realize the elongation of the overall size of the electric push rod assembly 6 Or shorten, the taper pin ball head 24 of electric push rod assembly 6 will pull special-shaped claw 1, and special-shaped claw 1 will rotate with virtual kingpin 9, and special-shaped claw 1 drives wheel assembly to rotate again, realizes wheel steering.

The displacement of the extension or retraction of the push rod is detected by the displacement sensor 19, and it is monitored whether the expansion and contraction of the electric push rod main body 18 reaches the target value input by the central controller. If not, adjust the expansion and contraction of the electric pushrod main body 18 until it is consistent with the target value according to the monitoring value provided by the displacement sensor 19.

During this working mode, the EPS drive motor in the EPS steering gear assembly 31 is in a self-locking state and at the zero position without any corner state, and the rack inside the rack-and-pinion steering gear 32 cannot move.

In the second working mode, the chassis platform embodied by the utility model adopts a newly designed suspension and steering system, so that each wheel can realize independent and non-interfering steering, including steering with rear wheels Normal steering mode, spot steering mode, horizontal movement mode and parking mode.

A. Normal steering mode with rear wheel follow-up steering

As shown in Figure 12, the two wheel assemblies 8 on both sides of the front portion of the vehicle frame 4 rotate to the left (the angle of rotation can be different), and the two wheel assemblies 8 on both sides of the rear portion of the vehicle frame 4 rotate to the right (the angle of rotation can be different). Can be different), at this time, the four wheels rotate around a point on the left side of the vehicle body as the center of circle to realize the common steering function.

Let up be the front of the vehicle. In this mode, the electric push rod control system does not work all the time, and the front and rear EPS motor modules complete the steering action.

When the required rotation angle signal is transmitted to the vehicle controller, the processed signal is transmitted to the EPS controller, and the EPS controller controls the EPS motor to work. According to the rotation angle signal fed back in real time by the rotation angle sensor on the EPS motor module, when the target is reached The EPS motor stops working after the corner. At this time, the output angle of the motor is transmitted to the input shaft of the steering gear through the universal joint, and the input shaft rotates. Because the inside of the steering gear is a rack and pinion structure, the rack and pinion steering gear converts the rotation pair into a translation pair, so there is an input shaft The input angle changes, and the rack outputs the displacement variable, and then the steering rod drives the special-shaped steering knuckle and the wheel to rotate around the virtual kingpin to realize the steering action. At this time, the front wheel steering function in the normal mode is realized.

This mode also has the rear wheel follow-up steering function, and the steering angle signal is processed by the vehicle controller to output a new signal to the rear wheel EPS controller. Assuming that the front wheels need to turn left, the front wheel EPS motor controls the front wheel steering gear rack to move to the right to realize left turning. At this time, after the rear wheel EPS motor receives the signal, it controls the rear wheel steering gear rack to move to the right to realize follow-up steering Function.

B. In situ steering mode

As shown in Figure 13, the two wheel assemblies 8 on the left front and the right rear of the vehicle frame 4 rotate to the right, and the two wheel assemblies 8 on the left rear and the right front of the vehicle frame 4 rotate to the left. At this time, the four wheels revolve around the center of the vehicle body. One of the points is the center of the circle and turns to realize the in-situ steering function.

Let up be the front of the vehicle. Before entering this mode, the front and rear wheels should be in the straight-ahead position, and the EPS corner sensor is at the zero position at this time. At the same time, in this mode, the EPS motor cannot perform other actions and is always at the zero position. In this mode, the elongation of the electric push rod assembly is realized by controlling the push rod motor.

When the in-situ steering function is activated and the vehicle controller VCU obtains the target rotation angle, the four push rod motors start working synchronously to perform the action of extending the electric push rod. When the controller detects that the signal output by the sensor meets the required elongation, the corresponding push rod motor stops working and locks the mechanism. At this time, the four wheels are tangent to the same circle, and the center of the circle is the midpoint of the line connecting the center points of the front and rear axles. Then the drive motor controls the four wheels to rotate with the corresponding torque and rotation direction. When the rotation angle reaches the target corner, the braking action is performed and the vehicle stops.

C. Horizontal traverse mode

As shown in Figure 14, the four wheel assemblies 8 at the front, rear, left, and right sides of the vehicle frame 4 all rotate to be perpendicular to the original normal driving direction. At this time, the four wheels move horizontally and laterally along the direction perpendicular to the length of the vehicle body to realize the horizontal traversing function.

Let up be the front of the vehicle. Before entering this mode, the front and rear wheels should be in the straight-ahead position, and the EPS corner sensor is at the zero mark position at this time. At the same time, in this mode, the EPS motor cannot perform other actions and is always at the zero position. In this mode, the elongation of the electric push rod assembly is realized by controlling the push rod motor.

When the horizontal traverse function is activated and the vehicle controller VCU receives the direction signal, the four push rod motors start working synchronously to perform the action of extending the electric push rod. When the controller detects that the signal output by the sensor meets the required elongation, the corresponding push rod motor stops working and locks the mechanism. At this time, the four wheels have rotated 90° relative to the initial state and are in a horizontal position. Then the drive motor controls the four wheels to rotate with the corresponding torque and direction of rotation. When the platform moves horizontally to the target position, the braking action is performed and the vehicle stops.

D. Parking mode

As shown in Figure 15, the two wheel assemblies 8 on the left front and right rear of the vehicle frame 4 rotate to the left, and the two wheel assemblies 8 on the left rear and right front of the vehicle frame 4 rotate to the right. All directions cannot be rotated to realize the parking function.

Let up be the front of the vehicle. Before entering this mode, the front and rear wheels should be in the straight-ahead position, and the EPS corner sensor is at the zero mark position at this time. At the same time, in this mode, the EPS motor cannot perform other actions and is always at the zero position. In this mode, the shortening of the electric push rod assembly is realized by controlling the push rod motor.

When the parking function is activated and the vehicle controller VCU receives the control signal, the four push rod motors start to work synchronously to execute the shortening action of the electric push rod. When the controller detects that the signal output by the sensor meets the required shortening amount, the corresponding push rod motor stops working and locks the mechanism. After completing the execution of this mode, the position of the four-wheel mechanism forms a mechanical lock, and the vehicle cannot move in place.

It can be seen that the technical scheme of the utility model realizes the steering function of four special modes, and has a larger steering angle than the traditional steering system. Taking the toe angle of the left front wheel as an example, the range of the steering angle is -90° to 35° °, where -35° to 35° meets the steering requirements of the normal mode, and -90° to -35° meets the in-situ steering and horizontal traversing modes.

Claims (7)

1. a kind of distributed driving chassis platform for realizing four-wheel independent steering, it is characterised in that: including body frame (4), four A suspension fork mechanism and the EPS turning machine assembly being installed between two wheel sets (8) of body frame (4) front and rear part two sides (31) and transverse leaf spring assembly (5), body frame (4) are mounted on one between four wheel sets (8) of quadrangle respectively Suspension fork mechanism, each suspension fork mechanism includes special-shaped goat's horn (1), Top Crossbeam (3), electric pushrod assembly (6) and lower swing arm (7), different Shape goat's horn (1) is located above wheel set (8), and special-shaped goat's horn (1) lower end connects wheel set (8), in the middle part of special-shaped goat's horn (1) and Top is connected to body frame (4) through lower swing arm (7), Top Crossbeam (3) respectively, through electric pushrod assembly in the middle part of special-shaped goat's horn (1) (6) it is connected to the side output end of EPS turning machine assembly (31), a side end of transverse leaf spring assembly (5) is connected to cross Arm (3).

2. a kind of distributed driving chassis platform for realizing four-wheel independent steering according to claim 1, it is characterised in that: The Top Crossbeam (3) is mainly assembled by straight pin bulb (10), swing arm main body (11), two upper arm bush (12), is put Arm body (11) is in herringbone, and the lambdoid set end of swing arm main body (11) is through on straight pin bulb (10) and special-shaped goat's horn (1) Flexural pivot connection is held, lambdoid two divergent ends of swing arm main body (11) are through uniaxial at the top of upper arm bush (12) and body frame (4) Rotation is hinged；The lower swing arm (7) is mainly by fish-eye type bulb (25), welded pipe main body (26) and two bush for lower arm (27) Assemble, welded pipe main body (26) is in herringbone, and the lambdoid set end of welded pipe main body (26) is through fish-eye type bulb (25) It is connected with flexural pivot in the middle part of special-shaped goat's horn (1), lambdoid two divergent ends of welded pipe main body (26) are through bush for lower arm (27) and vehicle Uniaxial rotation is hinged in the middle part of body skeleton (4)；The straight pin bulb (10) of the Top Crossbeam (3) is located at the flake of lower swing arm (7) Right above formula bulb (25), the line of centres of straight pin bulb (10) and fish-eye type bulb (25) is as virtual stub (9), virtually Stub (9) passes through the core wheel of wheel set (8)；

The electric pushrod assembly (6) is mainly by electric pushrod main body (18), displacement sensor (19), screw thread swivel sleeve (23), conical surface pin bulb (24) assembles, and displacement sensor (19) is fixedly connected by displacement transducer mounting bracket (20) To electric pushrod main body (18), the probe rod of displacement sensor (19) and the push rod parallel arrangement of electric pushrod main body (18), and Between it is affixed by displacement sensor driving arm (22), the push rod end of electric pushrod main body (18) stretch out after with screw thread conversion sleeve One end of cylinder (23) is affixed, and the other end of screw thread swivel sleeve (23) installs conical surface pin bulb (24), conical surface pin bulb (24) ball It cuts with scissors in the L-type support that special-shaped goat's horn (1) side is equipped with；Electric pushrod main body (18) turns through screw thread conversion support (17) and EPS It is affixed to wherein one end of machine assembly (31) both ends output end；

The transverse leaf spring assembly (5) is mainly assembled by steel plate leaf spring (14), shackle bracket (13), steel plate leaf spring (14) On both sides of the middle be fixed on body frame (4) through fixed bracket (15) levels of two leaf spring vehicle bodies, the end of steel plate leaf spring (14) Portion is leaf spring ends mounting bracket (16), swing arm of the leaf spring ends mounting bracket (16) through shackle bracket (13) and Top Crossbeam (3) Main body (11) is hinged.

3. a kind of distributed driving chassis platform for realizing four-wheel independent steering according to claim 2, it is characterised in that: Hingedly, shackle bracket (13) other end is hinged to swing arm for described shackle bracket (13) one end and leaf spring ends mounting bracket (16) Main body (11) lambdoid middle part.

4. a kind of distributed driving chassis platform for realizing four-wheel independent steering according to claim 2, it is characterised in that: The EPS turning machine assembly (31) is mainly by pinion-and-rack steering engine (32), universal joint (33), EPS driving motor (34) group Fill, EPS driving motor (34) is fixed on body frame (4), EPS driving motor (34) output shaft through universal joint (33) and The input terminal of pinion-and-rack steering engine (32) connects, pinion-and-rack steering engine (32) output end.

5. a kind of distributed driving chassis platform for realizing four-wheel independent steering according to claim 1, it is characterised in that: The special-shaped goat's horn (1) is formed by multiple Split type supporting stand assembly and connections, is divided into Z-shaped three sections, the lower end of upper section is under Connected between the upper end of section by horizontal segment, upper section and lower section it is vertical simultaneously and horizontal segment is vertical, lower section is located at wheel set (8) Interior side simultaneously connects wheel set (8), and upper section is located above wheel set (8) after horizontal segment is bent.

6. a kind of distributed driving chassis platform for realizing four-wheel independent steering according to claim 1, it is characterised in that: The wheel set (8) is mainly assembled by tire (28), wheel rim (29) and hub motor (30), and wheel rim (29) is installed outside Tire (28), wheel rim (29) center installation hub motor (30), the stationary part of hub motor (30) are connected to special-shaped goat's horn (1) Bottom end.

7. a kind of distributed driving chassis platform for realizing four-wheel independent steering according to claim 1 or 2, feature exist In: the transverse leaf spring assembly (5) replaces with column damper, and column damper is connected to body frame (4) and Top Crossbeam (3) between.