A non-coal pure electric trackless mine car with a drive-by-wire chassis

Abstract

A kind of chassis of wire control for underground non-coal pure electric trackless mine car, including frame steel structure, power transmission system, brake system, steering system and suspension system.Frame steel structure is formed by the bolt connection of longitudinal beam riveted by double-layer or more bending steel plate and modular cross beam, and is divided into first to fourth installation areas from front to back, and each function mounting seat is fixed to longitudinal beam using modular structure.Power transmission system receives instructions through CAN communication to output torque.Suspension system includes disconnected independent balance shaft, two independent balance shafts are fixed on the side of two longitudinal beams and connected by pull rod, and matched with six upper and lower push rods with same size.Steering system uses electro-hydraulic combined power steering gear, which receives vehicle VCU signal and forms closed-loop control with steering angle sensor.The present application is a whole pure electric chassis developed and designed for pure electric and unmanned driving technology.

Description

Technical Field

[0001] This invention relates to the field of engineering vehicle technology, and in particular to a wire-controlled chassis for a pure electric trackless mining vehicle for underground non-coal mining. Background Technology

[0002] The underground non-coal transportation environment is characterized by bumpy, potholed conditions, dampness, and narrow operating roads, coupled with poor ventilation. Traditional fuel-powered dump trucks generate significant pollution and noise, seriously impacting the health of drivers and passengers. Therefore, promoting the electrification of underground transportation vehicles is of paramount importance. Currently, the electrification of trackless mining vehicles for non-coal mining in China is not yet widespread, and most vehicles that have obtained underground transport qualifications are fuel-powered dump trucks.

[0003] As the most important system component of a vehicle, the chassis's structural strength directly affects the vehicle's operational stability and service life, while the selection and parameters of its components determine the vehicle's handling. Due to the special operating conditions of underground roadways, the chassis structure must meet the requirements of rust and corrosion resistance, acid corrosion resistance, high reliability, and high safety; at the same time, limited by the confined space underground, the chassis structure must also have characteristics such as low height, narrow width, and small turning radius.

[0004] Based on the main structure of the chassis, there are two main types of existing underground non-coal trackless mining car chassis: Articulated chassis: The front and rear frames are connected by an articulated structure in the middle. Its advantages include flexible steering and a small turning radius, making it suitable for turning in narrow alleys. However, its structural space is limited. If pure electrification is implemented, the power battery can usually only be placed in the hood at the front of the cab. In the event of a frontal collision, the power battery poses a significant risk of fire and explosion, affecting the overall vehicle safety.

[0005] Integral chassis: The frame is an integral through-beam structure, characterized by high structural rigidity, outstanding torsional and bending resistance, and good driving stability. However, traditional integral chassis often have main and sub-frames. Installing the power battery on top of these subframes makes it difficult to control the overall vehicle height, hindering operation in confined spaces. Furthermore, the removal of systems such as the engine drastically alters the internal equipment layout, making it impossible to directly upgrade existing integral chassis to drive-by-wire chassis, hindering the realization of autonomous driving capabilities, and failing to meet the future development needs of unmanned and automated underground transportation. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a wire-controlled chassis for a pure electric trackless mining vehicle for non-coal mining underground. It is an integrated pure electric wire-controlled chassis developed and designed for pure electrification and unmanned driving technology. It solves the problem of high height of traditional integrated chassis by eliminating the subframe while ensuring that the overall strength of the chassis is not weakened. It also eliminates the related systems and equipment of the fuel engine and rationally arranges the three electric systems on the chassis structure.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is: a wire-controlled chassis for a pure electric trackless mining car for underground non-coal mining, including a frame steel structure, a power transmission system, a braking system, a steering system and a suspension system; The vehicle frame steel structure includes two longitudinal beams and six transverse beams. Connecting seats are provided on the inner sides of the longitudinal beams corresponding to the positions of the transverse beams. The connecting seats are fixed to the longitudinal beams with bolts, and the transverse beams are fixed to the connecting seats with bolts. The longitudinal beams are fixed by riveting two or more layers of bent steel plates. The vehicle frame steel structure, from front to back, consists of a first mounting area, a second mounting area, a third mounting area, and a fourth mounting area. The first mounting area is located in front of the front axle, and the second and third mounting areas are located between the front axle and the middle and rear axles. A steering gear mounting seat is fixed to the longitudinal beam on one side of the first mounting area, and a battery mounting seat is fixed to the longitudinal beam on the other side. A multi-function controller mounting seat is fixed to the longitudinal beam in the middle of the first mounting area. The second mounting area has a cab mounting seat and a powertrain mounting seat fixed to the longitudinal beam, with the powertrain mounting seat located below the cab mounting seat. The third mounting area has a power battery mounting seat fixed to the longitudinal beam. The fourth mounting area has a cargo box mounting seat fixed to the longitudinal beam. The powertrain system includes a traction motor and a gearbox. The powertrain system receives commands via CAN communication to drive the traction motor and output torque. The suspension system includes shock absorbers, leaf springs, balance shafts, and thrust rods. The balance shafts are disconnectable independent balance shafts, with two independent balance shafts fixed to the sides of the two longitudinal beams of the frame, connected by tie rods. The leaf springs are fixed to the independent balance shafts using diagonal U-bolts. The thrust rods include two upper thrust rods and four lower thrust rods. One upper thrust rod is hinged at one end to the crossbeam and at the other end to the top of the middle axle. The other upper thrust rod is hinged at one end to the crossbeam and at the other end to the top of the rear axle. Two lower thrust rods are paired to correspond to one independent balance shaft. One lower thrust rod is hinged at one end to the lower part of the independent balance shaft and at the other end to the middle axle. The other lower thrust rod is hinged at one end to the lower part of the independent balance shaft and at the other end to the rear axle. The six thrust rods are of the same size and specifications. The steering system includes a steering wheel, steering column, steering universal joint, steering drive shaft, steering gear, steering arm, and steering tie rod. When the steering wheel is turned, the steering column transmits the rotational force to the steering gear, which drives the steering arm to swing back and forth. The steering arm then drives the steering knuckle to rotate around the kingpin through the steering tie rod, ultimately turning the wheel.

[0008] As an improvement, the crossbeams are arranged from front to back as a first crossbeam, a second crossbeam, a third crossbeam, a fourth crossbeam, a fifth crossbeam, and a sixth crossbeam; the fourth crossbeam is located in the middle of the frame steel structure and includes two fourth crossbeam units that are symmetrically spaced apart from left to right, and the two fourth crossbeam units and the connecting seats at both ends form a U-shaped structure; the fifth crossbeam is composed of two merged fifth crossbeam units, and two upper thrust rods are respectively connected to the two fifth crossbeam units.

[0009] As an improvement, each mounting bracket is a modular structure, which is fixed to the longitudinal beam of the frame by bolts, avoiding shearing of the mounting bolts, and ensuring that the assembly and disassembly of each mounting bracket does not interfere with each other.

[0010] As an improvement, the axle adopts a mining-specific axle with a load capacity of 9+16+16t.

[0011] As an improvement, the original location of the internal combustion engine in the chassis structure is now occupied by a high-voltage box and a multi-function controller; the power battery is located above the frame and between the cab and the cargo box.

[0012] As an improvement, the position analysis of the initial hard point of the steering arm: straight line BD 1 Let the straight-line distance of the steering tie rod in space be the radius. Draw a sphere with the center of the ball joint when the vehicle turns left or right as the center. The point where the sphere intersects the steering drop arm circle AB in space is the hard point. This point is the position of the steering drop arm and the steering tie rod ball joint when the vehicle turns left or right.

[0013] As an improvement, the chassis is equipped with a lift-to-position sensor and a lift-to-lower sensor. The lift-to-position sensor uses distance sensing to stop lifting the cargo box after it has been raised to 45°. The lift-to-lower sensor notifies the driver and passengers in the cab after the cargo box has been lowered into position. The chassis uses an electro-hydraulic power steering system. The vehicle's VCU transmits signals to the steering system. After receiving a steering command, the steering system drives the drop arm and steering tie rod to move through the aforementioned steering system, thus achieving automatic vehicle steering. The chassis is also equipped with a steering angle sensor. The lower half of the angle sensor is mounted on the kingpin, and the upper half is mounted on the front axle. When the tires rotate a certain angle, the upper and lower parts of the angle sensor will rotate relative to each other. The angle sensor transmits the rotation angle data to the vehicle's VCU, thus forming a closed loop with the aforementioned automatic steering function.

[0014] The beneficial effects of this invention compared to the prior art are: 1. Improved vehicle passability: By eliminating the subframe design, the overall vehicle height is significantly reduced (e.g., by 100mm), enhancing the vehicle's ability to pass through narrow alleys; 2. Improved safety: The layout of the "three-electric" system has been optimized, placing the power battery in the area above the vehicle frame and between the cab and the cargo box where the collision risk is minimized, effectively reducing the risk of collision and fire; at the same time, the center of gravity distribution of the front and rear axles of the vehicle is more reasonable. 3. Optimized suspension system performance and convenient maintenance: The use of a disconnectable independent balance shaft lowers the vehicle's center of gravity, improves driving stability, and enables single-sided maintenance, reducing repair costs and time; by optimizing the mounting bracket structure, the six thrust rods are made to be of the same specification, avoiding incorrect installation and simplifying production and spare parts management; 4. Possesses the foundation for unmanned driving: The chassis integrates an electro-hydraulic power steering system, angle sensor, lifting sensor, and CAN communication interface, forming a complete drive-by-wire chassis. It can realize steering, lifting, and power transmission functions in unmanned driving mode, providing a reliable platform for realizing unmanned and automated underground transportation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the chassis of the present invention.

[0016] Figure 2 This is a schematic diagram of the steel structure of the vehicle frame.

[0017] Figure 3 This is a sectional view of the steel structure of the vehicle frame.

[0018] Figure 4 This is a schematic diagram of the front axle.

[0019] Figure 5 This is a partial schematic diagram of the steering system.

[0020] Figure 6 This is a top view of the middle and rear axle.

[0021] Figure 7 This is a bottom view of the middle and rear axle.

[0022] Figure 8 This is a sectional view of the middle and rear axle.

[0023] Figure 9 This is a diagram showing the position analysis of the initial hard point of the steering boom. Detailed Implementation

[0024] The present invention will now be further described with reference to the accompanying drawings.

[0025] like Figure 1 As shown, a wire-controlled chassis for a pure electric trackless mining vehicle for non-coal mining underground mainly consists of a steel frame structure 1, a power transmission system 2, a braking system, a steering system 3, a suspension system 4, and an unmanned driving interface.

[0026] like Figure 2 , 3As shown, the frame steel structure 1 includes two longitudinal beams 11 and six transverse beams 12. The inner side of the longitudinal beams 11 is provided with connecting seats 18 corresponding to the positions of the transverse beams 12. The connecting seats 18 are fixed to the longitudinal beams 11 by bolts, and the transverse beams 12 are fixed to the connecting seats 18 by bolts. The longitudinal beams 11 are fixed by riveting two or more layers of bent steel plates 111. The bent steel plates 111 are in the shape of channel steel and have good bending strength. The vehicle frame steel structure 1 consists of a first mounting area, a second mounting area, a third mounting area, and a fourth mounting area, arranged sequentially from front to back. The first mounting area is located in front of the front axle, while the second and third mounting areas are located between the front axle and the middle and rear axles. The first mounting area has a steering gear mounting seat 13 fixed to the longitudinal beam 11 on its left side, a battery mounting seat 14 fixed to the longitudinal beam 11 on its right side, and a multi-function controller mounting seat fixed to the longitudinal beam 11 in the middle. The second mounting area has a cab mounting seat 16 and a power transmission system mounting seat 15 fixed to the longitudinal beam 11, with the power transmission system mounting seat 15 located below the cab mounting seat 16. The third mounting area has a power battery mounting seat 17 fixed to the longitudinal beam 11. The fourth mounting area has a cargo box mounting seat fixed to the longitudinal beam 11. The crossbeams 12 are arranged from front to back as follows: first crossbeam, second crossbeam, third crossbeam, fourth crossbeam, fifth crossbeam, and sixth crossbeam. The fourth crossbeam is located in the middle of the frame steel structure 1 and includes two fourth crossbeam units that are symmetrically spaced apart. The two fourth crossbeam units and the connecting seats 18 at both ends form a U-shaped structure. The fifth crossbeam is composed of two merged fifth crossbeam units, and two upper thrust rods are respectively connected to the two fifth crossbeam units.

[0027] The steel frame structure 1 of this invention eliminates the traditional main and subframe design, effectively reducing the overall vehicle height and improving passability. To ensure that the overall structural strength of the frame is not reduced, the frame adopts a "two longitudinal and six transverse" multi-layer riveted beam structure, and innovatively adds anti-torsional crossbeams in areas with high local stress. Compared with the traditional structure, this design significantly enhances the frame's resistance to plasticity, load-bearing capacity, and fatigue life. The mounting seats on the frame are all designed with structural stress resistance. Specifically, the sheet metal of the mounting seats rests directly on the frame, avoiding shearing of the mounting bolts and thus preventing component mounting support failure. At the same time, each mounting seat adopts a modular design, so that the assembly and disassembly of the mounting supports of each system do not interfere with each other, facilitating later maintenance.

[0028] The powertrain system 2 includes a traction motor and a gearbox. The powertrain system receives commands via CAN communication to drive the traction motor and output torque. The powertrain system replaces the traditional internal combustion engine with a traction motor and gearbox. In the chassis structure, the original location of the internal combustion engine is used to house the high-voltage box and the multi-function controller 5. Considering the narrow and uneven nature of the underground tunnels, to avoid the risk of collisions, the power battery is located above the vehicle frame, in the area between the cab and the cargo box. This area has the lowest risk of collision within the entire vehicle, minimizing the probability of a power battery collision and fire.

[0029] like Figures 6 to 8 As shown, the suspension system 4 includes a shock absorber, a leaf spring 47, a balance shaft, and thrust rods. The balance shaft is a disconnectable independent balance shaft 45. Two independent balance shafts 45 are respectively fixed to the sides of the two longitudinal beams 11 of the vehicle frame. The two independent balance shafts 45 are connected by a tie rod 46. The leaf spring 47 is fixed to the independent balance shaft 45 using diagonal U-bolts 48. The thrust rods include two upper thrust rods 43 and four lower thrust rods. One end of one upper thrust rod 43 is hinged to the crossbeam, and the other end is hinged to the top of the middle axle. One end of the other upper thrust rod 43 is hinged to the crossbeam, and the other end is hinged to the top of the rear axle. Two lower thrust rods correspond to one independent balance shaft 45. One end of one lower thrust rod is hinged to the lower part of the independent balance shaft 45, and the other end is hinged to the middle axle. One end of the other lower thrust rod is hinged to the lower part of the independent balance shaft 45, and the other end is hinged to the rear axle. The six thrust rods have the same size and specifications.

[0030] The balance shaft of this invention adopts a disconnectable independent balance shaft 45, which is directly fixed to the longitudinal beam 11 of the frame, eliminating the crankshaft and intermediate support of the traditional old-style balance shaft. This design lowers the center of gravity of the frame and the middle and rear axles, improving the stability of the vehicle during driving and cornering; it also enables single-sided maintenance, so when one side bushing fails, only the failed side component needs to be replaced, without large-scale disassembly, significantly reducing maintenance costs and time. Furthermore, the disconnectable independent balance shaft 45 is matched with a diagonal U-bolt, which, compared to a vertical arrangement, increases the effective working length of the leaf spring 47, better absorbing vibrations and providing greater clamping force to prevent the leaf spring 47 from shifting. The thrust rods adopt a direct-push type, with a total of six, including two upper thrust rods 43 and four lower thrust rods 44. The thrust rods are used to connect the frame and the axle, overcoming the limitation of the leaf spring 47 only transmitting vertical and lateral forces. To address the issues of inconsistent specifications of upper and lower thrust rods (43 and 44) ​​in traditional vehicle models, which lead to easy misinstallation and complex spare parts management, this invention redesigns and optimizes the structure of the thrust rod mounting brackets on the chassis and the balance shaft. This optimization ensures that the distances from the middle and rear axle mounting brackets to the chassis and balance shaft remain consistent, thereby ensuring that all six thrust rods have identical dimensions.

[0031] like Figure 4 , 5 As shown, the steering system 3 mainly consists of components such as a steering wheel, steering column, steering universal joint, steering drive shaft, steering gear 31, steering drop arm 33, and steering tie rod 32. To achieve autonomous driving functionality, the steering gear of this invention uses an electro-hydraulic power steering system. The vehicle's VCU can transmit steering commands to the steering gear, driving the steering drop arm and steering tie rod to move, thus achieving automatic vehicle steering. Simultaneously, to form a closed-loop control, a steering angle sensor is designed into the chassis. The lower half of this sensor is mounted on the kingpin, and the upper half is mounted on the axle. When the tires rotate, the sensor feeds back the detected angle data to the vehicle's VCU.

[0032] like Figure 9 As shown, the position analysis of the initial hard point of the steering arm: straight line BD 1 Let the straight-line distance of the steering tie rod in space be the radius. Draw a sphere with the center of the ball joint when the vehicle turns left or right as the center. The point where the sphere intersects the steering drop arm circle AB in space is the hard point. This point is the position of the steering drop arm and the steering tie rod ball joint when the vehicle turns left or right.

[0033] The chassis of this invention is a drive-by-wire chassis, equipped with a lift-to-position sensor and a lift-to-lower sensor. The lift-to-position sensor uses distance sensing to stop lifting the cargo box after it has been raised 45°. The lift-to-lower sensor notifies the driver and passengers in the cab after the cargo box has been lowered into position. The chassis uses an electro-hydraulic power steering system. The vehicle's VCU transmits signals to the steering system. Upon receiving a steering command, the steering system drives the drop arm and steering tie rod to move, achieving automatic vehicle steering. The chassis also includes a steering angle sensor. The lower half of the angle sensor is mounted on the kingpin, and the upper half is mounted on the front axle. When the tires rotate a certain angle, the upper and lower parts of the angle sensor rotate relative to each other. The angle sensor transmits the rotation angle data to the vehicle's VCU, thus forming a closed-loop circuit with the automatic steering function.

Claims

1. A wire-controlled chassis for a pure electric trackless mining vehicle for non-coal mining, comprising a frame steel structure, a power transmission system, a braking system, a steering system, and a suspension system; characterized in that: The vehicle frame steel structure includes two longitudinal beams and six transverse beams. Connecting seats are provided on the inner sides of the longitudinal beams corresponding to the positions of the transverse beams. The connecting seats are fixed to the longitudinal beams with bolts, and the transverse beams are fixed to the connecting seats with bolts. The longitudinal beams are fixed by riveting two or more layers of bent steel plates. The vehicle frame steel structure, from front to back, consists of a first mounting area, a second mounting area, a third mounting area, and a fourth mounting area. The first mounting area is located in front of the front axle, and the second and third mounting areas are located between the front axle and the middle and rear axles. A steering gear mounting seat is fixed to the longitudinal beam on one side of the first mounting area, and a battery mounting seat is fixed to the longitudinal beam on the other side. A multi-function controller mounting seat is fixed to the longitudinal beam in the middle of the first mounting area. The second mounting area has a cab mounting seat and a powertrain mounting seat fixed to the longitudinal beam, with the powertrain mounting seat located below the cab mounting seat. The third mounting area has a power battery mounting seat fixed to the longitudinal beam. The fourth mounting area has a cargo box mounting seat fixed to the longitudinal beam. The powertrain system includes a traction motor and a gearbox. The powertrain system receives commands via CAN communication to drive the traction motor and output torque. The suspension system includes shock absorbers, leaf springs, balance shafts, and thrust rods. The balance shafts are disconnectable independent balance shafts, with two independent balance shafts fixed to the sides of the two longitudinal beams of the frame, connected by tie rods. The leaf springs are fixed to the independent balance shafts using diagonal U-bolts. The thrust rods include two upper thrust rods and four lower thrust rods. One upper thrust rod is hinged at one end to the crossbeam and at the other end to the top of the middle axle. The other upper thrust rod is hinged at one end to the crossbeam and at the other end to the top of the rear axle. Two lower thrust rods are paired to correspond to one independent balance shaft. One lower thrust rod is hinged at one end to the lower part of the independent balance shaft and at the other end to the middle axle. The other lower thrust rod is hinged at one end to the lower part of the independent balance shaft and at the other end to the rear axle. The six thrust rods are of the same size and specifications. The steering system includes a steering wheel, steering column, steering universal joint, steering drive shaft, steering gear, steering arm, and steering tie rod. When the steering wheel is turned, the steering column transmits the rotational force to the steering gear, which drives the steering arm to swing back and forth. The steering arm then drives the steering knuckle to rotate around the kingpin through the steering tie rod, ultimately turning the wheel.

2. The wire-controlled chassis of a pure electric trackless mining car for underground non-coal mining as described in claim 1, characterized in that: The crossbeams, from front to back, are the first crossbeam, the second crossbeam, the third crossbeam, the fourth crossbeam, the fifth crossbeam, and the sixth crossbeam. The fourth crossbeam is located in the middle of the frame steel structure and includes two fourth crossbeam units that are symmetrically spaced apart. The two fourth crossbeam units and the connecting seats at both ends form a U-shaped structure. The fifth crossbeam is composed of two merged fifth crossbeam units, and two upper thrust rods are respectively connected to the two fifth crossbeam units.

3. The wire-controlled chassis of a pure electric trackless mining car for underground non-coal mining as described in claim 1, characterized in that: Each mounting bracket has a modular structure and is fixed to the longitudinal beams of the frame with bolts, which prevents the mounting bolts from being sheared and ensures that the assembly and disassembly of each mounting bracket does not interfere with each other.

4. The wire-controlled chassis of a pure electric trackless mining car for underground non-coal mining as described in claim 1, characterized in that: The axle is a mining-specific axle with a load capacity of 9+16+16t.

5. The wire-controlled chassis of a pure electric trackless mining car for underground non-coal mining as described in claim 1, characterized in that: In terms of chassis structure, the original location of the fuel engine is now occupied by a high-voltage box and a multi-function controller; the power battery is located above the frame and between the cab and the cargo box.

6. The wire-controlled chassis of a pure electric trackless mining car for underground non-coal mining as described in claim 1, characterized in that: Analysis of the initial hard point position of the steering arm: Straight line BD 1 Let the straight-line distance of the steering tie rod in space be the radius. Draw a sphere with the center of the ball joint when the vehicle turns left or right as the center. The point where the sphere intersects the steering drop arm circle AB in space is the hard point. This point is the position of the steering drop arm and the steering tie rod ball joint when the vehicle turns left or right.

7. The wire-controlled chassis of a pure electric trackless mining car for underground non-coal mining as described in claim 1, characterized in that: The chassis is equipped with a lift-to-position sensor and a lift-to-lower sensor. The lift-to-position sensor uses distance sensing to stop lifting the cargo box after it has been raised to 45°. The lift-to-lower sensor notifies the driver and passengers in the cab after the cargo box has been lowered into position. The chassis uses an electro-hydraulic power steering system. The vehicle's VCU transmits signals to the steering system. After receiving a steering command, the steering system drives the drop arm and steering tie rod to move through the aforementioned steering system, thus achieving automatic vehicle steering. The chassis is also equipped with a steering angle sensor. The lower half of the angle sensor is mounted on the kingpin, and the upper half is mounted on the front axle. When the tires rotate a certain angle, the upper and lower parts of the angle sensor will rotate relative to each other. The angle sensor transmits the rotation angle data to the vehicle's VCU, thus forming a closed loop with the aforementioned automatic steering function.

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