A brake-by-wire device

Abstract

The present invention provides a wire-controlled braking device, including a pedal simulator, a shell, a master cylinder sub-assembly, a displacement sensor, a control unit and an electric power-assisting mechanism, wherein the pedal simulator includes a push rod and a pedal mounting seat; the master cylinder sub-assembly includes a master cylinder body, a master cylinder piston, a return spring and a master cylinder push rod; one end of the shell is connected to the pedal mounting seat, and the other end is connected to the master cylinder body, the lower end of the push rod is inserted into the cylindrical portion of the master cylinder push rod, the outer periphery of the cylindrical portion is provided with symmetrical axial sliding grooves and limiting bosses, and the rod-shaped portion of the master cylinder push rod is inserted into the master cylinder piston; the electric power-assisting mechanism includes a motor, a planetary gear set and a crankshaft-connecting rod slider structure that transmits to each other, the slider moves in the sliding groove of the master cylinder push rod and is respectively connected to the connecting rod, the other end of the connecting rod is movably connected to the crankshaft, the displacement sensor monitors the movement of the push rod and transmits the data to the control unit, the control unit controls the rotation or stop of the motor, and then acts on the master cylinder push rod through the crankshaft-connecting rod slider structure to achieve braking.

Description

Technical Field

[0001] The invention belongs to the technical field of wire-controlled braking and relates to a wire-controlled braking device. Background Art

[0002] The traditional automobile brake assist technology solution mainly consists of a vacuum pump + vacuum hose + vacuum tank + vacuum booster. This vacuum-assisted structure takes up a large space and is high in cost, and cannot be linearly controlled.

[0003] The trend toward intelligent driving is becoming increasingly evident. Level 3 and higher autonomous driving inevitably requires active braking, where the ECU directly controls the braking system based on road conditions. Existing vacuum-assisted braking solutions cannot meet this requirement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an electrically assisted brake-by-wire device.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a wire control brake device, including a pedal simulator, a housing, a rear cover, a master cylinder sub-assembly, a displacement sensor, a control unit and an electric power-assisting mechanism, the pedal simulator includes a push rod, a push rod connector, a push rod, a pedal mounting seat, the master cylinder sub-assembly includes a master cylinder body, a master cylinder piston, a return spring, a master cylinder push rod, and a hydraulic sensor; one end of the housing is connected to the pedal mounting seat, and the other end is connected to the master cylinder body; the master cylinder push rod includes a cylindrical portion and The lower end of the rod-shaped portion is interference-mounted with an extension rod, the rod-shaped portion and the extension rod are inserted into the master cylinder piston, the lower end of the push rod is inserted into the cylindrical portion of the master cylinder push rod, the outer circumference of the cylindrical portion of the master cylinder push rod is provided with two symmetrical axial slide grooves, and the lower end of the axial slide groove is provided with a limiting boss; the electric power assist mechanism includes a motor, a planetary gear set, two gears, two crankshafts, two connecting rods and two sliders, the two sliders are movably mounted in the axial slide grooves of the cylindrical portion of the master cylinder push rod, and the outer ends of the two sliders are respectively connected to a connecting rod The two crankshafts are movably connected, and the other end of the connecting rod is movably connected to the middle part of the crankshaft. The two ends of the crankshaft are mounted on the housing through bearings. A gear is fixedly mounted on each of the two crankshafts, and the two gears are meshed with each other. The end of one of the crankshafts is connected to the motor shaft through a planetary gear set. The displacement sensor, the control unit and the motor are electrically connected. The displacement sensor is used to monitor the movement distance of the push rod and transmit the data to the control unit. The control unit controls the motor to rotate forward, stop or reverse according to the received data. When the motor rotates forward, the two crankshafts rotate synchronously, and then drive the two sliders to move downward in the axial slot of the master cylinder push rod through the two connecting rods. When the sliders move to the limiting boss at the lower end of the axial slot, they will apply an axial downward force to the entire master cylinder push rod, and the master cylinder push rod will then transmit the downward force to the master cylinder piston. When the motor rotates reversely, the two crankshafts rotate synchronously, and then drive the two sliders to move upward in the axial slot of the master cylinder push rod through the two connecting rods. The master cylinder push rod will also move upward under the action of the return spring.

[0006] The above technical solution has two braking modes. Under normal circumstances, it is an electric braking mode. When the driver presses on the pedal simulator, the push rod of the pedal simulator will move downward but will not directly transmit force to the master cylinder. Instead, a displacement sensor is used to monitor the distance the push rod moves and transmit the data to the control unit. The control unit determines the driver's demand for braking force based on the push rod's depression depth detected by the position sensor, and then controls the number of rotations of the motor. The control unit then applies pressure to the master cylinder piston through the planetary gear, crank, connecting rod, slider, and master cylinder push rod, causing it to move backward, thereby building pressure and outputting the master cylinder. The master cylinder output pressure corresponding to the push rod displacement is adjustable through motor decoupling. During the master cylinder pressure building process, the master cylinder's hydraulic sensor can monitor the master cylinder's output pressure in real time and feed it back to the control unit, thus forming a closed-loop control. The other mode is a mechanical redundancy mode, which serves as an alternative solution in the event of motor failure. That is, the pedal pushes the push rod downward for a certain distance and continues to push the master cylinder push rod downward, which in turn pushes the master cylinder piston downward to release pressure and output, thereby achieving braking.

[0007] In one embodiment, the displacement sensor is mounted on the housing, a magnet matching the displacement sensor and a magnet mounting bracket are mounted in the middle of the push rod, and the displacement sensor detects the moving distance of the push rod according to the magnetic flux.

[0008] In one embodiment, the electric power assist mechanism further includes a motor cam, an elastic coupling and a crankshaft cam. The motor cam is interference-pressed onto the planetary gear set, the planetary gear set is interference-pressed onto the motor, the motor and the housing are fixedly connected by bolts, the crankshaft cam is interference-pressed onto the end of a crankshaft, and an elastic coupling is interference-installed between the motor cam and the crankshaft cam.

[0009] In one embodiment, a push rod buffer rubber is provided in the cylindrical portion of the master cylinder push rod, and a push rod buffer soft rubber is provided in the master cylinder piston.

[0010] In one embodiment, the pedal simulator further includes a pedal spring retaining ring, a first spring, a second spring, a pedal spring seat, and a mounting seat buffer rubber. The pedal spring retaining ring is pressed onto the push rod, the first spring is installed between the pedal spring seat and the pedal spring retaining ring, the upper end of the push rod connector is movably connected to the push rod, the middle part of the push rod is provided with a circle of limiting bosses integrally formed with the push rod, the upper end of the push rod passes through the axial hole of the pedal mounting seat and is threadedly connected to the push rod connector; the second spring is installed between the pedal spring seat and the pedal mounting seat; the magnet mounting bracket is interference-mounted below the limiting boss of the push rod, the magnet is fixed to the magnet mounting bracket by bolts, and the pedal mounting seat is fixedly connected to the housing by bolts. By providing the first spring and the second spring, the pedal feel requirement of variable stiffness can be met.

[0011] In one embodiment, one end of the connecting rod is movably connected to the middle part of the crankshaft, and a bushing is installed between the connecting rod and the crankshaft for self-lubrication. The other end of the connecting rod is connected to the slider through a fixing pin. The left end of the crankshaft is press-fitted with a bearing, and the right end is press-fitted with a gear and a bearing in sequence. A crankshaft claw is installed on the right end of one of the crankshafts. The pressed-fit crankshaft subassembly is installed in the housing, and then the rear cover is locked to the housing with bolts.

[0012] The beneficial effects of the present invention are: 1) through the cooperation between the pedal simulator, the master cylinder subassembly, the displacement sensor, the control unit and the electric power-assisting mechanism, the two modes of electric power-assisted braking and mechanical braking are perfectly combined to ensure the reliability of braking; 2) by directly electrically connecting the control unit of the present invention to the on-board computer (ECU), the on-board computer (ECU) can directly control the braking system based on the road conditions, thereby realizing active braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic longitudinal cross-sectional view of a brake-by-wire device in an embodiment of the present invention;

[0014] Figure 2 is a schematic cross-sectional view of a brake-by-wire device in an embodiment of the present invention;

[0015] Figure 3 Schematic diagram of the three-dimensional structure of the electric power assist mechanism in an embodiment of the present invention;

[0016] Figure 4 is an exploded view of the structure of a brake-by-wire device in an embodiment of the present invention;

[0017] Figure 5 Schematic diagram of the three-dimensional structure of the master cylinder sub-assembly in an embodiment of the present invention;

[0018] The accompanying drawings are:

[0019] 1. Dust cover; 2. Sponge pad; 3. Push rod; 4. Pedal spring retainer; 5. First spring; 6. Push rod connector; 7. Push rod; 8. Pedal spring seat; 9. Housing; 11. Back cover; 12. Motor; 13. Second spring; 14. Mounting seat cushion rubber; 18. Pedal mounting seat; 19. Magnet mounting bracket; 20. Magnet; 21. Displacement sensor; 23. Planetary gear set; 24. Motor cam; 25. Elastic coupling ; 26. Crankshaft claw; 29. ​​Bearing; 30. Gear; 31. Crankshaft; 34. Connecting rod; 35. Bushing; 36. Fixing pin; 38. Slider; 39. Push rod buffer rubber; 40. Master cylinder push rod; 41. Return spring; 42. Extension rod; 43. Push rod buffer rubber; 45. Master cylinder sub-assembly; 45a. Liquid reservoir; 45b. Liquid level sensor; 45c. Master cylinder body; 45d. Hydraulic sensor; 45e. Master cylinder piston. DETAILED DESCRIPTION

[0020] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and drawings. The contents mentioned in the embodiments are not intended to limit the present invention.

[0021] It should be noted that, in the present invention, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connected," and "fixed" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0022] like Figures 1 to 5As shown, a wire control brake device includes a pedal simulator, a housing 9, a rear cover 11, a master cylinder sub-assembly 45, a displacement sensor, a control unit and an electric power assist mechanism; the pedal simulator includes a push rod 3, a push rod connector 6, a push rod 7, a pedal mounting seat 18, a pedal spring retaining ring 4, a first spring 5, a second spring 13, a pedal spring seat 8, a mounting seat buffer rubber 14, a dust cover 1 and a sponge pad 2; the master cylinder sub-assembly 45 includes a master cylinder body 45c, a master cylinder piston 45e, a return spring 41, a master cylinder push rod 40, a hydraulic sensor 45d, a liquid storage pot 45a and a liquid level sensor 45b; one end of the housing 9 is connected to the pedal mounting seat 18, and the other end is connected to the The master cylinder body 45c is connected; the master cylinder push rod 40 includes a cylindrical portion and a rod-shaped portion, the lower end of the rod-shaped portion is interference-fitted with an extension rod 42, the rod-shaped portion and the extension rod 42 are inserted into the master cylinder piston 45e, and the master cylinder piston 45e is provided with a push rod buffer soft rubber 43, the lower end of the push rod 7 is inserted into the cylindrical portion of the master cylinder push rod 40, and the cylindrical portion is provided with a push rod buffer rubber 39. The outer peripheral surface of the cylindrical portion of the master cylinder push rod 40 is provided with two symmetrical axial grooves, and a limiting boss is provided at the lower end of the axial groove; the electric power assist mechanism includes a motor 12, a planetary gear set 23, two gears 30, two crankshafts 31, two connecting rods 34 and two sliders 38, and the two sliders 38 are movable The outer ends of the two sliders 38 are each movably connected to a connecting rod 34, and the other end of the connecting rod 34 is movably connected to the middle part of the crankshaft 31. The two ends of the crankshaft 31 are mounted on the housing 9 through bearings 29. A gear 30 is fixedly mounted on each of the two crankshafts 31. The two gears 30 are meshed with each other. The end of one of the crankshafts 31 is connected to the shaft of the motor 12 through a planetary gear set 23. The displacement sensor 21, the control unit and the motor 12 are electrically connected. The displacement sensor 21 is used to monitor the movement distance of the push rod 7 and transmit data to the control unit. The control unit adjusts the displacement sensor 21 according to the received data. To control the forward, stop or reverse rotation of the motor 12; when the motor 12 rotates forward, the two crankshafts 31 rotate synchronously, and then drive the two sliders 38 to move downward in the axial slot of the master cylinder push rod 40 through the two connecting rods 34. When the slider 38 moves to the limiting boss at the lower end of the axial slot, it will apply an axial downward force to the entire master cylinder push rod 40, and the master cylinder push rod 40 will then transmit the downward force to the master cylinder piston 45e; when the motor 12 reverses, the two crankshafts 31 rotate synchronously, and then drive the two sliders 38 to move upward in the axial slot of the master cylinder push rod 40 through the two connecting rods 34, and the master cylinder push rod 40 will also move upward under the action of the return spring 41.

[0023] like Figure 2 、 3As shown, the electric power assist mechanism also includes a motor claw 24, an elastic coupling 25 and a crankshaft claw 26. The motor claw 24 is press-fitted on the planetary gear set 23 by interference fit, and the planetary gear set 23 is press-fitted on the motor 12. The motor 12 is fixedly connected to the housing 9 by bolts. The crankshaft claw 26 is press-fitted on the end of a crankshaft 31, and an elastic coupling 25 is interference fitted between the motor claw 24 and the crankshaft claw 26; one end of the connecting rod 34 is movably connected to the middle part of the crankshaft 31, and a bushing 35 is installed between the connecting rod 34 and the crankshaft 31 for self-lubrication. The other end of the connecting rod 34 is connected to the slider 38 through a fixing pin 36. The left end of the crankshaft 31 is press-fitted with a bearing 29, and the right end is press-fitted with a gear 30 and a bearing 29 in turn. The right end of one of the crankshafts 31 is installed with a crankshaft claw 26. The press-fitted crankshaft 31 subassembly is installed in the housing 9, and then the rear cover 11 is locked on the housing 9 by bolts.

[0024] like Figure 1 、 2 As shown in Figures 4 and 5, the pedal spring retaining ring 4 of the pedal simulator is press-fitted onto the push rod 3, the first spring 5 is installed between the pedal spring seat 8 and the pedal spring retaining ring 4, the upper end of the push rod connector 6 is movably connected to the push rod 3, and the middle part of the push rod 7 is provided with a circle of limiting bosses integrally formed with the push rod 7. The upper end of the push rod 7 passes through the axial hole of the pedal mounting seat 18 and is threadedly connected to the push rod connector 6; the second spring 13 is installed between the pedal spring seat 8 and the pedal mounting seat 18; the magnet mounting bracket 19 is interference-fitted below the limiting boss of the push rod 7, the magnet 20 is fixed to the magnet mounting bracket 19 by bolts, the pedal mounting seat 18 is fixedly connected to the housing 9 by bolts, the pedal mounting seat 18 is installed with a mounting seat buffer rubber 14, and the displacement sensor 21 detects the movement distance of the push rod 7 according to the magnetic flux. By providing the first spring 5 and the second spring 13, the pedal feel requirement of variable stiffness can be met, and the resistance feedback can be provided to the driver to form a foot feel.

[0025] This embodiment has two braking modes. Under normal circumstances, it is an electric braking mode. When the driver presses the pedal simulator, the push rod 7 of the pedal simulator will move downward but will not directly transmit force to the master cylinder. Instead, the displacement sensor 21 monitors the movement distance of the push rod 7 and transmits the data to the control unit. The control unit determines the driver's demand for braking force based on the depth of the push rod 7 monitored by the displacement sensor 21, and then controls the number of rotations of the motor 12. The control unit then sequentially transmits the planetary gear 30, crank, connecting rod 34, slider 38, and master cylinder push rod 40 to provide pressure to the master cylinder piston 45e, causing it to move backward, thereby building up pressure in the master cylinder. The master cylinder output pressure corresponding to the displacement of the push rod 7 is adjustable by decoupling the motor 12. During the master cylinder pressure building process, the master cylinder's hydraulic sensor 45d can monitor the master cylinder's output pressure in real time and feed it back to the control unit, thus forming a closed-loop control. Another mode is the mechanical redundancy mode, which serves as an alternative when the motor 12 fails. That is, the pedal pushes the push rod 7 downward for a distance and continues to push the master cylinder push rod 40 downward, and then pushes the master cylinder piston 45e downward to decompress the output and achieve braking.

[0026] The beneficial effects of this embodiment are: 1) through the cooperation between the pedal simulator, the master cylinder sub-assembly 45, the displacement sensor 21, the control unit and the electric power-assisting mechanism, the two modes of electric power-assisted braking and mechanical braking are perfectly combined to ensure the reliability of braking; 2) by directly electrically connecting the control unit of the present invention to the on-board computer (ECU), the on-board computer (ECU) can directly control the braking system based on the road conditions, thereby realizing active braking.

[0027] In order to make it easier for ordinary technicians in this field to understand the improvements of the present invention over the prior art, some drawings and descriptions of the present invention have been simplified, and the above-mentioned embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the scope of protection of the present invention.

Claims

1. A brake-by-wire device, characterized in that: The invention comprises a pedal simulator, a housing (9), a rear cover (11), a master cylinder subassembly (45), a displacement sensor (21), a control unit and an electric power assist mechanism, wherein the pedal simulator comprises a push rod (3), a push rod connector (6), a push rod (7) and a pedal mounting seat (18), and the master cylinder subassembly (45) comprises a master cylinder body (45c), a master cylinder piston (45e), a return spring (41), a master cylinder push rod (40) and a hydraulic sensor (45d); one end of the housing (9) is connected to the pedal mounting seat (18), and the other end is connected to the master cylinder body (45c); the master cylinder push rod (40) comprises a cylindrical portion and a rod portion, and the lower end of the rod portion is interference-mounted with an extension The rod (42), the rod-shaped portion and the extension rod (42) are inserted into the master cylinder piston (45e), the lower end of the push rod (7) is inserted into the cylindrical portion of the master cylinder push rod (40), the outer peripheral surface of the cylindrical portion of the master cylinder push rod (40) is provided with two symmetrical axial sliding grooves, and a limiting boss is provided at the lower end of the axial sliding groove; the electric power assist mechanism includes a motor (12), a planetary gear set (23), two gears (30), two crankshafts (31), two connecting rods (34) and two sliders (38), the two sliders (38) are respectively movably installed in the axial sliding grooves of the cylindrical portion of the master cylinder push rod (40), the outer ends of the two sliders (38) are each movably connected to a connecting rod (34), and the connecting rod The other end of (34) is movably connected to the middle of the crankshaft (31), and the two ends of the crankshaft (31) are mounted on the housing (9) through bearings (29). A gear (30) is fixedly mounted on each of the two crankshafts (31), and the two gears (30) are meshed with each other. The end of one of the crankshafts (31) is connected to the motor shaft through a planetary gear set (23). The displacement sensor (21), the control unit and the motor (12) are electrically connected. The displacement sensor (21) is used to monitor the moving distance of the push rod (7) and transmit the data to the control unit. The control unit controls the motor (12) to rotate forward, stop or reverse according to the received data. When the motor (12) ) When the motor (12) rotates forward, the two crankshafts (31) rotate synchronously, and then the two sliders (38) are driven to move downward in the axial slot of the master cylinder push rod (40) through the two connecting rods (34). When the sliders (38) move to the limiting boss at the lower end of the axial slot, an axial downward pressure is applied to the entire master cylinder push rod (40), and the master cylinder push rod (40) then transmits the downward pressure to the master cylinder piston (45e); when the motor (12) rotates reversely, the two crankshafts (31) rotate synchronously, and then the two sliders (38) are driven to move upward in the axial slot of the master cylinder push rod (40) through the two connecting rods (34). The master cylinder push rod (40) also moves upward under the action of the return spring (41);One end of the connecting rod (34) is movably connected to the middle part of the crankshaft (31). A bushing (35) is installed between the connecting rod (34) and the crankshaft (31) for self-lubrication. The other end of the connecting rod (34) is connected to the slider (38) through a fixing pin (36). The left end of the crankshaft (31) is press-fitted with a bearing (29), and the right end is press-fitted with a gear (30) and a bearing (29) in sequence. The right end of one of the crankshafts (31) is installed with a crankshaft claw (26). The press-fitted crankshaft (31) subassembly is installed in the housing (9), and the rear cover (11) is locked on the housing (9) by bolts.

2. The brake-by-wire device structure according to claim 1, characterized in that: The displacement sensor (21) is mounted on the housing (9), and a magnet (20) and a magnet mounting bracket (19) that match the displacement sensor (21) are mounted in the middle of the push rod (7). The displacement sensor (21) detects the moving distance of the push rod (7) based on magnetic flux.

3. The brake-by-wire device structure according to claim 1 or 2, characterized in that: The electric power assist mechanism further comprises a motor pawl (24), an elastic coupling (25) and a crankshaft pawl (26); the motor pawl (24) is press-fitted onto the planetary gear set (23) by interference fit; the planetary gear set (23) is press-fitted onto the motor (12) by interference fit; the motor (12) and the housing (9) are fixedly connected by bolts; the crankshaft pawl (26) is press-fitted onto the end of a crankshaft (31); and an elastic coupling (25) is press-fitted between the motor pawl (24) and the crankshaft pawl (26) by interference fit.

4. The brake-by-wire device structure according to claim 1 or 2, characterized in that: A push rod buffer rubber (39) is provided in the cylindrical portion of the master cylinder push rod (40), and a push rod buffer soft rubber (43) is provided in the master cylinder piston (45e).

5. The brake-by-wire device structure according to claim 2, characterized in that: The pedal simulator further comprises a pedal spring retaining ring (4), a first spring (5), a second spring (13), a pedal spring seat (8), and a mounting seat buffer rubber (14). The pedal spring retaining ring (4) is pressed onto the push rod (3), the first spring (5) is mounted between the pedal spring seat (8) and the pedal spring retaining ring (4), the upper end of the push rod connector (6) is movably connected to the push rod (3), the middle part of the push rod (7) is provided with a circle of limiting bosses integrally formed with the push rod (7), the upper end of the push rod (7) passes through the axial hole of the pedal mounting seat (18) and is threadedly connected to the push rod connector (6); the second spring (13) is mounted between the pedal spring seat (8) and the pedal mounting seat (18); the magnet mounting bracket (19) is interference-mounted below the limiting boss of the push rod (7), the magnet (20) is fixed to the magnet mounting bracket (19) by bolts, and the pedal mounting seat (18) is fixedly connected to the housing (9) by bolts.

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