Redundant Electric Power Steering

Abstract

An embodiment of the present invention provides a redundant electric power steering device, which includes: a first circuit board and a second circuit board configured to control a motor; wherein the first circuit board and the second circuit board are stacked in a direction parallel to the end face of the motor housing; a plurality of control units are arranged on the first circuit board; the second circuit board includes a plurality of redundant parts; the plurality of redundant parts are located on the same plane; each redundant part is bent and connected to the first circuit board respectively. The redundant electric power steering device reduces the occupied space and component composition of the circuit board in the redundant electric power steering device, is conducive to improving the layout efficiency in the package, reducing the size of the package, improving the space utilization, and is conducive to overcoming the limitation of the installation space in the vehicle.

Description

Technical Field

[0001] The present invention relates to the field of control, and in particular to a redundant electric power steering device. Background Art

[0002] The Electric Power Steering (EPS) system is based on the traditional mechanical steering mechanism, with the addition of a signal sensor, an electronic control device and a steering assist mechanism. It uses the power generated by the electric motor to help the driver steer. When not steering, the motor does not work; when steering, the steering wheel torque and rotation direction signals detected by the torque sensor are transmitted to the control unit. The control unit sends instructions to the motor based on the torque size and direction and the vehicle speed signal from the vehicle speed sensor. The motor outputs a torque of corresponding size and direction to generate assistance.

[0003] At present, some systems, including EPS systems, use packaging technology that integrates the electronic control unit (ECU) that controls the motor's rotation speed and rotation torque with the motor. And with the continuous development of EPS technology, due to the limitations of size and space, the power unit structure with integrated motor and controller is becoming more and more popular, especially for components such as dual pinion DP-EPS and rack-assisted R-EPS where the steering gear is installed outside the cockpit, the installation space is even tighter. Therefore, in order to overcome the limitations of the installation space in the vehicle, it is necessary to improve the layout efficiency in the package and reduce the size of the package to improve space utilization.

[0004] However, with the increasing safety requirements for EPS controllers and the increase in the number of vehicle electrical systems, adding redundant electronic control units has become the main strategy for dealing with the above situation. In the existing redundant design, the two ECUs perform mutual monitoring and independent operation, and the hardware (H / W) structures of the two are almost exactly the same. Usually, the two ECUs are each made into a PCBA board for integration, which will inevitably increase the package size and the volume of the redundant electric drive control device structure, which is not conducive to overcoming the limitation of the installation space in the vehicle. Summary of the invention

[0005] The present specification provides a redundant electric power steering device to overcome at least one technical problem existing in the prior art.

[0006] According to an embodiment of the present specification, a redundant electric power steering device is provided, the redundant electric power steering device comprising: a first circuit board and a second circuit board configured to control a motor, the first circuit board and the second circuit board being stacked in a direction parallel to an end face of a housing of the motor,

[0007] The first circuit board is provided with a plurality of control units.

[0008] The second circuit board includes a plurality of redundant parts, the plurality of redundant parts are located on the same plane, and each of the redundant parts is respectively connected to the first circuit board in a bending manner.

[0009] Optionally, the number of the redundant parts is two,

[0010] The two redundant parts are axially centrally symmetrical with respect to the driving shaft of the motor.

[0011] Further optionally, the first circuit board and the second circuit board are both circular.

[0012] The second circuit board is divided into two semicircles to form two redundant parts, and all components arranged on the two redundant parts are centrally symmetrical with respect to the axial direction of the driving shaft of the motor.

[0013] Further optionally, the redundant electric power steering device further includes a connector,

[0014] The two redundant parts are connected to a set of connectors, and the two sets of connectors are centrally symmetrical with respect to the axial direction of the drive shaft of the motor.

[0015] Each group of connectors includes a first connector and a second connector.

[0016] Further optionally, the PIN pins of the two groups of connectors are respectively welded on the two redundant parts in a center-symmetrical manner.

[0017] The welding positions of the PIN pins of each group of the connectors are arranged linearly and distributed in parallel along a boundary line separating the two redundant parts.

[0018] Optionally, the motor is a six-phase brushless motor.

[0019] The PIN pins of the motor are divided into two groups with the same number. The two groups of PIN pins of the motor are respectively welded at positions of the two redundant parts far away from the center of the circle, and the PIN pins of each group of the motor are evenly distributed at equal distances.

[0020] Further optionally, the redundant electric power steering device further includes a base and a housing,

[0021] The upper and lower surfaces of the base are both provided with bosses, and the second circuit board and the first circuit board are respectively mounted on the upper and lower surfaces of the base, and are bonded to the bosses by thermal conductive adhesive.

[0022] The base, the first circuit board and the second circuit board are accommodated in the shell, the connector is welded on the second circuit board, and the interface of the connector is communicated with the external space of the shell.

[0023] Further optionally, the housing is provided with a ventilation channel.

[0024] One end of the air permeable channel is opened on the outer surface of the shell, and the other end is opened on the inner upper surface of the shell. A waterproof and breathable membrane is arranged in the end of the air permeable channel opened on the inner upper surface of the shell.

[0025] Further optionally, the base is mounted on an end face of a casing of the motor on the opposite side of an output portion of a drive shaft of the motor, and the housing is buckled onto one end of the casing of the motor on the opposite side of an output portion of the drive shaft of the motor to form a sealed space with the casing of the motor.

[0026] A plurality of downwardly extending mounting ears are arranged on the side surface of the base, and mounting holes are opened on the mounting ears. A mounting part corresponding to the mounting ears is arranged on the housing end surface of the motor on the opposite side of the output part of the driving shaft of the motor, and the mounting ears are installed on the mounting part by passing screws through the mounting holes.

[0027] The outer shell is provided with a wrapping portion corresponding to the mounting ear. When the outer shell is buckled on the casing of the motor, the wrapping portion is buckled on the mounting portion, so that the mounting ear is placed in the sealed space between the outer shell and the casing of the motor.

[0028] Further optionally, three buckles are evenly arranged on the side surface of the shell along a circumferential angle of 120°, the buckles are spaced apart from the wrapping portion, and a clamping block corresponding to the buckle is arranged on the side surface of the casing of the motor.

[0029] The beneficial effects of the embodiments of this specification are as follows:

[0030] The redundant control is realized by using the upper and lower circuit boards with double folding, which reduces the occupied space and parts composition of the circuit boards in the redundant electric power steering device. It is not only conducive to improving the layout efficiency in the package and reducing the size of the package, but also compared with the redundant control device in the prior art, the number of structural assembly parts is halved, the installation process is shortened, the working hours, manpower and material resources are also greatly reduced, and the installation efficiency is improved. At the same time, the redundant electric power steering device is designed with the functions of fixing, connecting, cooling and grounding the circuit board on a base, realizing the integration of multiple functions, further reducing the size of the package and improving the space utilization. In addition, by making the upper and lower circuit boards parallel to the end face of the motor housing, the radial space is effectively utilized, the occupation of the axial space is reduced, and the overall volume of the device is reduced, which is conducive to overcoming the limitation of the installation space in the vehicle.

[0031] The technical effects of the embodiments of this specification include:

[0032] 1. In this embodiment, by combining a rigid circuit board with a flexible circuit board, the redundant control circuit board is designed as a double-sided folded upper and lower circuit board structure, so that the redundant control components are highly integrated, the board indirect plug-ins are reduced, and the occupied space of the overall redundant control circuit board is reduced, thereby improving space utilization and reducing the package size. This is one of the technical effects of the embodiments of this specification.

[0033] 2. In this embodiment, the base is used to connect the motor, and through the boss design thereon, it plays a role in fixing and supporting the upper and lower circuit boards, and also plays a role in grounding conduction. At the same time, it plays a role in heat dissipation by bonding the circuit boards with thermally conductive adhesive. The base integrates the functions of fixing, connecting, heat dissipation, and grounding, eliminating most of the structures, saving assembly parts, and making installation simpler and easier to implement. It is one of the technical effects of the embodiments of this specification.

[0034] 3. In this embodiment, the upper and lower circuit boards are parallel to the end surface of the motor casing, which effectively utilizes the radial space and reduces the axial space occupied, thereby reducing the volume of the redundant control device, which is one of the technical effects of the embodiments of this specification.

[0035] 4. In this embodiment, a wrapping portion for accommodating the mounting ear is provided on the outer shell. Under the premise of ensuring that the overall volume of the device is as small as possible, the mounting ear and the mounting screws thereon are wrapped inside the outer shell. This can not only improve the sealing of the overall structure, but also effectively avoid salt spray corrosion that may be caused by the screws. This is one of the technical effects of the embodiments of this specification.

[0036] 5. In this embodiment, when the glue used for sealing between the outer shell and the motor casing is not dry, the outer shell of the redundant electric power steering device and the motor casing are fixed by a snap-on design, which is conducive to uniform drying of the glue, realizes the connection between the two, and ensures the sealing of the internal space of the outer shell, which is one of the technical effects of the embodiments of this specification.

[0037] 6. In this embodiment, a waterproof and breathable membrane with the characteristics of being waterproof, dustproof, oil-proof, chemical-resistant, high and low temperature-resistant, and aging-resistant is arranged on the top of the shell, so that the protection level of the redundant electric power steering device can reach IP6K9K, and the waterproof and breathable membrane is welded on the top of the shell, which is convenient for operation and easy to implement. At the same time, the opening connecting the inside of the shell with the outside world is designed on the side of the shell through a breathable channel, which effectively saves space for installing a breathable valve, which is one of the technical effects of the embodiments of this specification.

[0038] 7. In this embodiment, the circuit board is designed to be circular according to the cylindrical shape of the motor, and the second circuit board is designed to be two semicircles, and the layout of the second circuit board and all the devices thereon are centrally symmetrical. Since the devices on the two semicircles are the same, that is, the completely identical structure is centrally symmetrical, the structural distribution layout is more uniform, and more space is saved, which is one of the technical effects of the embodiments of this specification.

[0039] 8. In the present embodiment, the EPS system adopts a redundant architecture. When any controller malfunctions, it can determine whether normal instructions can be transmitted through communication between circuit boards to ensure that the system function is not degraded based on the abnormal state of the system. Thus, when a signal or component fails, the system function can be maximized while ensuring functional safety. This is one of the technical effects of the embodiments of this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A front view of a redundant electric power steering device provided in an embodiment of this specification;

[0042] Figure 2 A top view of a redundant electric power steering device provided in an embodiment of this specification;

[0043] Figure 3 An exploded schematic diagram of a portion of the structure of a redundant electric power steering device provided in an embodiment of this specification;

[0044] Figure 4 A schematic diagram of the structure of a redundant electric power steering device provided in an embodiment of this specification without a housing installed;

[0045] Figure 5 A top view of a redundant electric power steering device without a housing installed provided for an embodiment of this specification;

[0046] Figure 6 A schematic diagram of the structure of a circuit board in a redundant electric power steering device provided in an embodiment of this specification;

[0047] Figure 7 A schematic diagram of the structure of a housing in a redundant electric power steering device provided in an embodiment of this specification;

[0048] Figure 8 A bottom view schematic diagram of a housing in a redundant electric power steering device provided in an embodiment of this specification;

[0049] Fig. 9 A schematic diagram of the structure of a circuit board and a connector in a redundant electric power steering device provided in an embodiment of this specification;

[0050] Fig.10 A schematic diagram of the structure of a base in a redundant electric power steering device provided in an embodiment of this specification;

[0051] Fig.11 A schematic diagram of the structure of a buckle in a redundant electric power steering device provided in an embodiment of this specification;

[0052] Explanation of the reference numerals: 1 is a motor, 2 is a casing, 3 is a drive shaft, 4 is an outer shell, 5 is a mounting portion, 6 is a wrapping portion, 7 is a buckle, 8 is a block, 9 is a limit strip, 10 is one end of the air permeable channel, 11 is a connector, 12 is a screw, 13 is a plug end PIN pin of a motor PIN group, 14 is a circuit board, 15 is a base, 16 is a mounting bolt, 17 is a top opening of the outer shell, 18 is a first vertical portion, 19 is a second vertical portion, 20 is a connecting portion, 21 is a waterproof breathable membrane, 22 is a first connector, 23 is a second connector, 24 is a second circuit board, 25 is a first circuit board, 26 is a flexible connecting plate, 27 is a through groove, 28 is a mounting hole, 29 is a mounting ear, 30 is a base body, 31 is a boss, 32 is a positioning pin, 33 is a threaded hole, and 34 is a fixing portion. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be noted that the terms "including" and "having" and any variations thereof in the embodiments of this specification and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0055] Redundant control is an effective means to meet the requirements of continuous production and improve system availability. With the intensification of competition in the manufacturing industry, manufacturers are more pursuing the reliability of production equipment, especially for equipment that controls key production processes, which often requires redundant configuration. At present, most redundant systems based on programmable controllers use at least two sets of processor modules, that is, at least two independent control units are designed. The redundant design in the prior art sets the two control units on two independent circuit boards, and adds another circuit board on the basis of the original circuit board. The dual circuit boards set in this way will inevitably increase the package size and the volume of the redundant control device, thereby making the overall volume of the redundant electric power steering device larger, which is not conducive to overcoming the limitation of the installation space in the vehicle.

[0056] Based on this, an embodiment of this specification provides a redundant electric power steering device, which is a device for assisting the driver's steering operation in transportation equipment such as automobiles. It has high integration, small size, and realizes the electric power steering control function in a narrow space.

[0057] Figure 1 – Fig.11 A redundant electric power steering device according to an embodiment of this specification is shown. Figure 1 – Fig.11 As shown, the redundant electric power steering device includes: a motor 1, a base 15, a housing 4, a connector 11, and a circuit board 14 configured to control the motor 1. The circuit board 14, the base 15, and a portion of the connector 11 are accommodated in the housing 4, the connector 11, the circuit board 14, and the base 15 are sequentially connected and mounted on the motor 1 through the base 15, the motor 1 is electrically connected to the circuit board 14, and the circuit board 14 is used to control the motor 1.

[0058] Specifically, the circuit board 14 is the main structure of the redundant electric power steering device, and is combined with Figure 6 As shown, the circuit board 14 includes a first circuit board 25 and a second circuit board 24, and the first circuit board 25 and the second circuit board 24 are stacked in a direction parallel to the end face of the casing 2 of the motor 1, that is, the first circuit board 25 and the second circuit board 24 are stacked up and down, and the three planes of the first circuit board 25, the second circuit board 24 and the end face of the casing 2 of the motor 1 are parallel to each other, so as to effectively utilize the radial space and utilize the maximum effective use area within the minimum space in the axial direction of the driving shaft 3 of the motor 1 as much as possible, thereby reducing the occupation of the axial space and minimizing the occupied space of the circuit board relative to the overall device.

[0059] To achieve redundant control, a plurality of control units (not shown in the figure) are provided on the first circuit board 25, and correspondingly, the second circuit board 24 includes a plurality of redundant parts, the number of which is the same as the number of control units, and the redundant parts correspond to the control units one by one, so that each control unit is respectively connected to a set of power devices to form multiple sets of processor modules, thereby achieving multilateral redundancy and independent control. In the embodiments of this specification, a set of power devices includes but is not limited to connectors, MOS tubes, capacitors and inductors, and a set of processor modules includes but is not limited to control devices, connectors, MOS tubes, capacitors and inductors, and the circuit board 14 can be a printed circuit board (PCB), and the control unit is also called a control device or a controller.

[0060] The multiple redundant parts in the second circuit board 24 are located on the same plane, and each redundant part is bent and connected to the first circuit board 25, that is, the redundant parts of the first circuit board 25 and the second circuit board 24 are bent and parallel using a semi-flexible printed circuit board (Semi-Flex PCB), forming bilateral redundancy, and can be independently controlled, thereby effectively utilizing the radial space, reducing the occupation of the axial space, and greatly reducing the overall volume of the device. In a specific embodiment, the number of redundant parts is two, and the two redundant parts are bent and connected to the first circuit board 25 through a flexible connecting plate 26, forming a bilateral folded circuit board structure, wherein the flexible connecting plate 26 is a flexible circuit board, on which circuit board wiring is arranged, so that the first circuit board 25 and the devices on the redundant parts are interconnected through the circuit board wiring. The second circuit board 24 adopts a centrosymmetric design divided into two, and the two redundant parts are centrosymmetric relative to the axial direction of the drive shaft of the motor 1. In order to further reduce the overall volume of the redundant electric power steering device, the shapes of the first circuit board 25 and the second circuit board 24 are designed to be circular corresponding to the shape of the end face of the housing 2 of the motor 1, and the second circuit board 24 is divided into two semicircles to form two centrally symmetrical redundant parts, and all devices arranged on the two redundant parts are designed to be centrally symmetrical relative to the axial direction of the drive shaft of the motor 1. This design can make the two sets of processor modules have exactly the same structure centrally symmetrical, thereby making the structural layout more uniform and compact, greatly saving the layout space of the circuit board.

[0061] The connector 11 is a device that connects two active devices and is used to transmit current or signal. In the embodiment of this specification, in order to effectively prevent errors in plugging and unplugging of the wiring harness end, under the condition of realizing redundant power supply and signal input and output, the connector 11 is designed as two groups of separate connectors, which are distinguished by function. Each group of connectors 11 includes: a power connector, a signal connector and a TAS connector. Both redundant parts are connected to a group of connectors 11. Each group of connectors 11 is an interface that connects the corresponding control unit to an external power supply and an external device. Each group of connectors 11 is independent of each other. In a specific embodiment, an appropriate connector male interface is selected, and each group of connectors 11 includes a first connector 22 and a second connector 23. The power PIN and the signal PIN are integrated in one male interface, namely the first connector 22, and the multiple PINs of TAS are another male interface, namely the second connector 23, so as to reduce the occupied space of the connector 11 as much as possible while meeting the function. At the same time, the two groups of connectors 11 are also centrally symmetrical with respect to the axial direction of the drive shaft of the motor 1, ensuring that the same structures on the two sets of processor modules are centrally symmetrical, so that the layout is more uniform and compact, and the space occupied by the connectors 11 is smaller.

[0062] In another specific embodiment, the PIN pins of the two groups of connectors 11 are respectively symmetrically welded on the two redundant parts. At the same time, in order to allow more space on the circuit board 14 for arranging other electronic components, such as Figure 6 As shown, the welding positions of the PIN pins of each group of connectors are arranged linearly and distributed in parallel along the boundary line separating the two redundant parts, so that there is more remaining space on the second circuit board for arranging other electronic components, thereby ensuring that the first circuit board and the two semicircular redundant parts that occupy a smaller space can be used to arrange two sets of processor modules.

[0063] The base 15 is mainly used to install the circuit board 14 on the motor 1, and plays a role in fixing and supporting the circuit board 14. Since the circuit board 14 in the embodiment of this specification adopts a double-sided folded upper and lower circuit board structure, in order to simultaneously ensure the fixed support of the first circuit board 25 and the second circuit board 24, the second circuit board 24 and the first circuit board 25 are respectively installed on the upper and lower surfaces of the base 15, and the flexible connecting plate 26 is arranged on the side of the base 15, respectively connecting the redundant parts of the first circuit board 25 and the second circuit board 24. In a specific embodiment, as Figure 3 and Fig.10 As shown, the base 15 includes a base body 30 and a fixing portion 34. A plurality of fixing portions 34 for mounting and fixing the circuit board 14 are provided on the upper and lower surfaces of the base body 30. The fixing portions 34 are provided with threaded holes 33. The threaded holes 33 on the fixing portions 34 are penetrated by the mounting bolts 16, and the second circuit board and the first circuit board are respectively mounted on the upper and lower surfaces of the base 15. In a specific implementation process, the threaded holes 33 on the lower surface of the base body 30 are penetrated by the mounting bolts 16, and the first circuit board is mounted on the lower surface of the base 15. The plurality of redundant portions are folded onto the upper surface of the base body 30 by the flexible connecting plate, and then the threaded holes 33 on the upper surface of the base body 30 are penetrated by the mounting bolts 16, and the plurality of second circuit boards are respectively fixedly mounted on the upper surface of the base 15, thereby completing the installation of the circuit board 14 on the base 15. The operation is simple, and the connection is firm and stable.

[0064] Furthermore, since the high-power devices connected to the circuit board 14 have large heat consumption, in order to ensure the stable and reliable operation of the redundant control device, it is necessary to design a heat dissipation design for the high-power devices. In the embodiment of the present specification, bosses 31 are provided on the upper and lower surfaces of the base 15, that is, bosses 31 are provided on the upper and lower surfaces of the base body 30, and the first circuit board, the second circuit board and the bosses 31 are bonded together by thermally conductive adhesive. The bosses 31 on the upper and lower surfaces of the base body 30 are respectively designed according to the MOS tubes on the second circuit board and the first circuit board and the copper exposed area at the pre-drive position, so that the bosses 31 are connected to the areas where the second circuit board and the first circuit board need to dissipate heat, and the second circuit board and the first circuit board are bonded together by thermally conductive adhesive to dissipate heat, thereby ensuring the stable operation of the high-power devices. Such a design eliminates the need for a separate heat dissipation device in the redundant electric power steering device and reduces the overall volume of the redundant electric power steering device. In a specific implementation process, the height of the boss 31 is smaller than the height of the fixing portion 34 , so that when the first circuit board and the second circuit board are installed on the base 15 , there is a certain gap between the boss 31 and the first circuit board and the second circuit board, providing space for the setting of the thermal conductive adhesive.

[0065] In order to enable the circuit board 14 to be quickly and accurately installed on the base 15, in the embodiment of the present specification, a positioning pin 32 is also provided on the fixing portion 34, and corresponding positioning holes (not shown in the figure) are respectively provided on the first circuit board and the second circuit board, so that the circuit board 14 can be accurately and quickly positioned on the base 15 by inserting the positioning pin 32 into the positioning holes on the first circuit board and the second circuit board, thereby achieving quick installation.

[0066] The base 15 is installed on the end face of the housing 2 of the motor 1 on the opposite side of the output part of the drive shaft 3 of the motor 1, so that the circuit board 14 and the connector 11 in the redundant electric power steering device are fixedly connected to the end face of the housing 2, and the housing 4 is buckled on one end of the housing 2 of the motor 1 on the opposite side of the output part of the drive shaft 3 of the motor 1, and a sealed space is formed between the housing 4 and the housing 2 of the motor 1, and the base 15, the circuit board 14 and the connector 11 are partially contained in the sealed space to play a protective role.

[0067] In addition, in a specific embodiment, the base 15 fixes the circuit board 14 through a plurality of mounting bolts 16, and the base 15 and the circuit board 14 are mounted on the motor 1 through screws 12, so that the current can be transmitted to the base 15 through the mounting bolts 16, and then transmitted to the motor 1 through the screws 12, so as to achieve the purpose of grounding, that is, the base 15 not only plays the role of fixing and supporting the circuit board 14 and connecting the motor 1, but also plays the role of grounding conduction. In the embodiment of this specification, the base 15 has the functions of fixing, connecting, heat dissipation and grounding, and integrates multiple functions in one, omitting most structures, saving assembly parts, and reducing the overall volume of the redundant electric power steering device.

[0068] In another specific embodiment, in order to minimize the overall volume of the redundant electric power steering device and ensure the stability of the connection between the base 15 and the motor 1, a plurality of mounting portions 5 are provided on the end face of the housing 2 of the motor 1 on the opposite side of the output portion of the drive shaft 3 of the motor 1. Correspondingly, a plurality of downwardly extending mounting ears 29 are provided on the side surface of the base 15. The mounting ears 29 correspond to the mounting portions 5 of the motor 1, and mounting holes 28 are provided on the mounting ears 29. The mounting ears 29 are installed on the mounting portions 5 by screws 12 passing through the mounting holes 28, so that the base 15 and the circuit board 14 and the connector 11 thereon are fixed on the end face of the housing 2. Furthermore, a wrapping portion 6 corresponding to the mounting ear 29 is provided on the outer shell 4. When the outer shell 4 is buckled on the casing 2 of the motor 1, the wrapping portion 6 is buckled on the mounting portion 5, so that the mounting ear 29 is placed in the sealed space between the outer shell 4 and the casing 2 of the motor 1, thereby partially wrapping the base 15 and the circuit board 14 and the connector 11 thereon in the outer shell 4. At the same time, the screws 12 used for connection are also wrapped in the outer shell 4. Since the redundant electric power steering device is installed on the chassis, its salt spray test requirements are relatively high. The wrapping portion 6 of the outer shell 4 directly wraps all the screws 12 to avoid some screws being difficult to meet the design requirements of the salt spray test.

[0069] In the embodiment of the present specification, the shell 4 serves as a protective structure, which is snapped onto the casing 2 of the motor 1, and the base 15, the first circuit board 25, and the second circuit board 24 are accommodated in the shell 4. The connector 11 is welded on the second circuit board 24, and a part of it is accommodated in the shell 4. The interface is connected to the external space of the shell 4, which plays a protective role for the base 15, the first circuit board 25, the second circuit board 24, and the connector 11. In a specific embodiment, three buckles 7 are evenly arranged along the circumferential direction of 120° on the side surface of the shell 4. Correspondingly, a card block 8 corresponding to the buckle 7 is arranged on the side surface of the casing 2 of the motor 1. The card block 8 is snapped into the buckle 7 to snap the shell 4 onto the casing 2. Since the shell 4 and the casing 2 are sealed by gluing, the casing 2 is snapped onto the shell 4 after gluing. When the glue between the two is not dry, the buckle 7 fixes the shell 4 and the casing 2, which is conducive to uniform drying of the glue, and is more conducive to achieving connection between the two and ensuring sealing. For details, combined with Fig.11 As shown, the buckle 7 includes a first vertical portion 18, a second vertical portion 19 and a connecting portion 20. One end of the first vertical portion 18 and the second vertical portion 19 are respectively fixed to the side surface of the housing 4, and the other ends of the first vertical portion 18 and the second vertical portion 19 are connected through the connecting portion 20. The first vertical portion 18, the second vertical portion 19 and the connecting portion 20 form a buckle 7 for clamping the clamping block 8. In addition, a limiting strip 9 is respectively provided on both sides of the clamping block 8. When the clamping block 8 is clamped in the buckle 7, the first vertical portion 18 is clamped between one of the limiting strips 9 and the clamping block 8, and the second vertical portion 19 is clamped between the other limiting strip 9 and the clamping block 8. On the one hand, it is convenient for the quick and accurate positioning of the connection between the housing 4 and the casing 2, and on the other hand, it can further strengthen the stability of the connection between the housing 4 and the casing 2. In order to avoid interference between structures in the redundant electric power steering device, the buckle 7 and the wrapping part 6 are arranged at intervals. In the specific implementation process, three wrapping parts 6, buckles 7, mounting parts 5 and blocks 8 are respectively arranged, evenly distributed at 120° in the circumferential direction, and the three wrapping parts 6 and the three buckles 7 are arranged at intervals. Correspondingly, the three mounting parts 5 and the three blocks 8 are also arranged at intervals.

[0070] The motor 1 of the redundant electric power steering device is a six-way brushless motor, which can be regarded as two three-phase motors. In the specific implementation process, the PIN pins of the motor 1 are divided into two groups with the same number, in order to form a short-distance transmission circuit, such as Figure 4As shown, the two groups of PIN pins of the motor 1 are respectively welded at positions of the two redundant parts away from the center of the circle, and each group of PIN pins of the motor 1 is evenly distributed at equal distances. That is to say, the PIN pins of the motor 1 are respectively (three pairs of three) penetrated through the through slots 27 on the first circuit board 25 and welded on the two redundant parts, so that the power supply is an independent input. The motor 1 obtains power from the control unit through the motor interface, and also feeds back the motor position information, current information, etc. to the control unit through the motor interface. The control unit drives the three-phase bridge circuit to output the required torque through the current closed-loop control.

[0071] In the embodiment of the present specification, the redundant EPS controller of the electric drive redundant electric power steering device is two controllers, and the two controllers arranged on the first circuit board 25 communicate with each other through Ethernet or CAN FD. Through the arrangement of the connector 11 and the components on the circuit board 14, the redundant control device has two independent power supply systems, ignition systems and CAN buses on the periphery, and is composed of two independent TAS sensors, redundant EPS controllers and six-phase brushless motors. The single EPS controller is composed of a power processing module, an MCU minimum system, a torque sensor power supply module, a torque sensor conditioning circuit module, a temperature control module and a CAN communication module, a motor drive module and a motor current sampling module. At the same time, in order to improve the functional safety of the system, a shutdown MOS can also be set for each phase, and when a phase fails, the output of the phase can be cut off.

[0072] During the application process, the redundant EPS controller obtains system power supply and ignition signals from two independent power supply systems of the vehicle through the redundant interface of the vehicle, obtains information such as the engine speed, vehicle speed, and ADAS request of the vehicle through two independent CAN buses, and transmits the EPS system status and information on the response to ADAS through the CAN bus, and obtains the steering wheel angle and torque signal through the TAS interface, where the sensor output signal type is the SPC signal. According to the vehicle input and TAS input, the controller provides appropriate assistance through the drive motor. In this process, the motor obtains power from the controller through the motor interface, and also feeds back the motor position information, current information, etc. to the controller through the motor interface. The controller drives the three-phase bridge circuit to output the required torque through current closed-loop control.

[0073] Since the EPS system of the electric power steering device adopts a redundant architecture, when the signal or component fails, it can maximize the guarantee that the system function will not be degraded while ensuring functional safety. When any controller is abnormal, it can determine whether normal instructions can be transmitted through communication between circuit boards to ensure that the system function is not degraded according to the abnormal state of the system.

[0074] In summary, this specification discloses a redundant electric power steering device, which uses a double-sided folded upper and lower circuit board to achieve redundant control, reducing the space occupied by the circuit board and the components in the redundant electric power steering device, which is not only conducive to improving the layout efficiency in the package and reducing the size of the package, but also compared with the redundant control device in the prior art, the number of structural assembly parts is halved, the installation process is shortened, and the working hours, manpower and material resources are also greatly reduced, which improves the installation efficiency. At the same time, the redundant electric power steering device is designed with the functions of fixing, connecting, cooling and grounding the circuit board on a base, realizing the integration of multiple functions, further reducing the size of the package and improving the space utilization. In addition, by making the upper and lower circuit boards parallel to the end face of the motor casing, the radial space is effectively utilized, the occupation of the axial space is reduced, and the overall volume of the device is reduced, which is conducive to overcoming the limitation of the installation space in the vehicle.

[0075] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition and explanation in the subsequent drawings.

[0076] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0078] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A redundant electric power steering device, characterized in that: The redundant electric power steering device comprises: a first circuit board and a second circuit board configured to control a motor, wherein the first circuit board and the second circuit board are stacked in a direction parallel to an end surface of a housing of the motor. The first circuit board is provided with a plurality of control units. The second circuit board includes a plurality of redundant parts, the number of the redundant parts is the same as the number of the control units, and the redundant parts correspond to the control units one by one, the plurality of redundant parts are located on the same plane, and each of the redundant parts is bent and connected to the first circuit board respectively; There are two redundant parts, and the two redundant parts are respectively connected to the first circuit board by bending through a flexible connecting plate, and the two redundant parts are centrally symmetrical with respect to the axial direction of the driving shaft of the motor. The first circuit board and the second circuit board are both circular, the second circuit board is divided into two semicircles to form two redundant parts, and all devices arranged on the two redundant parts are centrally symmetrical with respect to the axial direction of the driving shaft of the motor.

2. The redundant electric power steering device according to claim 1, characterized in that: The redundant electric power steering device also includes a connector, The two redundant parts are connected to a set of connectors, and the two sets of connectors are centrally symmetrical with respect to the axial direction of the drive shaft of the motor. Each group of connectors includes a first connector and a second connector.

3. The redundant electric power steering device according to claim 2, characterized in that: The PIN pins of the two groups of connectors are respectively welded on the two redundant parts in a center-symmetrical manner. The welding positions of the PIN pins of each group of the connectors are arranged linearly and distributed in parallel along a boundary line separating the two redundant parts.

4. The redundant electric power steering device according to any one of claims 1 to 3, characterized in that: The motor is a six-phase brushless motor. The PIN pins of the motor are divided into two groups with the same number. The two groups of PIN pins of the motor are respectively welded at positions of the two redundant parts far away from the center of the circle, and the PIN pins of each group of the motor are evenly distributed at equal distances.

5. The redundant electric power steering device according to claim 2, characterized in that: The redundant electric power steering device further includes a base and a housing. The upper and lower surfaces of the base are both provided with bosses, and the second circuit board and the first circuit board are respectively mounted on the upper and lower surfaces of the base, and are bonded to the bosses by thermal conductive adhesive. The base, the first circuit board and the second circuit board are accommodated in the shell, the connector is welded on the second circuit board, and the interface of the connector is communicated with the external space of the shell.

6. The redundant electric power steering device according to claim 5, characterized in that: The shell is provided with a ventilation channel. One end of the air permeable channel is opened on the outer surface of the shell, and the other end is opened on the inner upper surface of the shell. A waterproof and breathable membrane is arranged in the end of the air permeable channel opened on the inner upper surface of the shell.

7. The redundant electric power steering device according to claim 5, characterized in that: The base is mounted on the end face of the motor housing on the opposite side of the output portion of the motor drive shaft, and the housing is buckled on one end of the motor housing on the opposite side of the output portion of the motor drive shaft to form a sealed space with the motor housing. A plurality of downwardly extending mounting ears are arranged on the side surface of the base, and mounting holes are opened on the mounting ears. A mounting part corresponding to the mounting ears is arranged on the housing end surface of the motor on the opposite side of the output part of the driving shaft of the motor, and the mounting ears are installed on the mounting part by passing screws through the mounting holes. The outer shell is provided with a wrapping portion corresponding to the mounting ear. When the outer shell is buckled on the casing of the motor, the wrapping portion is buckled on the mounting portion, so that the mounting ear is placed in the sealed space between the outer shell and the casing of the motor.

8. The redundant electric power steering device according to claim 7, characterized in that: Three buckles are evenly arranged on the side surface of the shell along a circumferential angle of 120°, the buckles are spaced apart from the wrapping portion, and a clamping block corresponding to the buckles is arranged on the side surface of the housing of the motor.

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