Parking brake system and control method thereof

Abstract

The invention provides a parking braking system and a control method thereof.The parking braking system comprises a braking device and a parking device, the braking device comprises a caliper body, a braking motor, a lead screw, a piston and a brake caliper assembly, the braking motor is connected to the caliper body and is in transmission connection to the lead screw, and the piston is in threaded connection to the lead screw and is slidably connected to the caliper body in the axial direction of the lead screw; the piston can move between a braking position and a separating position in the axial direction of the lead screw, the brake caliper assembly is connected to the end of the piston, and the piston is provided with an abutting face opposite to the brake caliper assembly. The parking device comprises a parking driving piece connected to the caliper body and a parking plug connected to the output end of the parking driving piece, and the parking driving piece can drive the parking plug to move and abut against the abutting face when the piston is located at the braking position. The position of the piston is kept fixed through abutting of the parking plug, so that the control precision of the brake caliper assembly is improved, meanwhile, the axial length of the brake caliper assembly is not increased, and the arrangement space in a vehicle is saved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle braking, and in particular relates to a parking brake system and a control method thereof. Background Art

[0002] The Electro-Mechanical Brake (EMB) system needs to ensure fast and precise control of the braking force during driving braking. The EMB structure must adopt a mechanical structure with high transmission efficiency and cannot adopt a self-locking structure with low transmission efficiency. Therefore, the parking function requirement when the vehicle stops cannot be achieved, and a parking device needs to be installed on the EMB.

[0003] Currently, most parking devices on EMBs use a ratchet pawl structure or a radial ratchet engagement parking structure. Both structures have common problems. For example, the number of ratchet teeth limits the control accuracy. For example, if the number of ratchet teeth is 12, then parking can only be performed at every 30° central angle of the ratchet shaft. Summary of the invention

[0004] The object of the present invention is to provide a parking brake system and a control method thereof, aiming to solve the technical problem of poor control accuracy of the current parking system.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a parking brake system is provided, comprising:

[0007] A brake device, comprising a caliper body, a brake driver, a piston and a brake caliper assembly, wherein the brake driver is connected to the caliper body and is drivingly connected to the piston, the brake driver can drive the piston to move along its own axis between a braking position and a release position, the brake caliper assembly is connected to an end of the piston, the piston moves from the release position to the braking position by moving toward the brake caliper assembly, and the piston has an abutment surface facing away from the brake caliper assembly;

[0008] The parking device comprises a parking drive connected to the caliper body and a parking plug connected to the output end of the parking drive. The parking drive can drive the parking plug to move and abut against the abutment surface when the piston is in the braking position.

[0009] As one possible implementation of the first aspect, the brake drive component includes a brake motor and a screw, the brake motor is connected to the caliper body and is transmission-connected to the screw, the piston is threaded on the screw and is slidably connected to the caliper body along its own axial direction, the brake motor can drive the screw to rotate so that the piston moves between the braking position and the separation position along the axial direction of the screw, the parking drive component includes a parking motor and a threaded shaft connected to the output end of the parking motor, the parking plug is threaded on the threaded shaft and is slidably connected to the caliper body along the axial direction of the threaded shaft, wherein the axial direction of the threaded shaft is the same as the axial direction of the piston.

[0010] In a second aspect, a control method of a parking brake system is provided, which is applied to the parking brake system described in the above embodiments, and the control method of the parking brake system includes:

[0011] When a parking signal is received, the brake driving member is controlled to drive the piston forward so that the piston moves from the current position to the braking position;

[0012] After the piston moves to the braking position, the parking drive member is controlled to drive the parking plug forward until the parking plug is tightly pressed against the abutting surface, thereby completing parking;

[0013] When a release signal is received, the parking drive member is controlled to drive the parking plug to retreat so that the parking plug is separated from the abutment surface;

[0014] After the parking plug is separated from the abutment surface, the brake drive member is controlled to drive the piston to move from the braking position to the separation position to complete the parking release.

[0015] As one possible implementation of the second aspect, when the release signal is received and the parking plug has not retracted, the brake drive component is first controlled to drive the piston to increase the clamping force applied toward the brake caliper assembly, and then the parking drive component is controlled to drive the parking plug to retract after the clamping force increases.

[0016] As one possible implementation of the second aspect, if a displacement stroke signal of the brake pedal is received before the parking signal is received, the brake drive component is controlled to output a corresponding braking force according to the displacement stroke signal of the brake pedal, so that the piston moves from the separation position to the current position.

[0017] As one possible implementation manner of the second aspect, controlling the brake driver to drive the piston forward so that the piston moves from a current position to the brake position includes:

[0018] When receiving a parking signal, determine whether the parking slope is less than or equal to 8°;

[0019] If the parking slope is less than or equal to 8°, the brake driver is controlled to drive the piston forward, so that the piston moves from the current position to the braking position, and the current of the brake driver reaches the first parking current;

[0020] If the parking slope is greater than 8°, the brake driver is controlled to drive the piston forward, so that the piston moves from the current position to the braking position, and the current of the brake driver reaches the second parking current;

[0021] Wherein, the second parking current is greater than the first parking current.

[0022] As one possible implementation manner of the second aspect, controlling the parking drive member to drive the parking plug forward until the parking plug is tightly pressed against the abutment surface includes:

[0023] determining the magnitude of the clamping force applied by the piston toward the brake caliper assembly and the parking demand clamping force;

[0024] When the clamping force is greater than or equal to the parking requirement clamping force, the parking drive member is controlled to drive the parking plug forward until the parking plug is pressed against the abutment surface;

[0025] When the clamping force is less than the parking requirement clamping force, the brake drive is controlled to drive the piston to increase the clamping force until the clamping force is greater than or equal to the parking requirement clamping force, and the parking drive is controlled to drive the parking plug forward until the parking plug is pressed against the abutment surface.

[0026] As one possible implementation manner of the second aspect, after the parking plug is pressed against the abutting surface, the method further includes:

[0027] Determine whether the wheel is rotating;

[0028] If the wheels do not turn, the parking action is complete;

[0029] If the wheel rotates, the brake driver is controlled to drive the piston forward until the wheel stops rotating, and the parking driver is controlled to drive the parking plug forward until it abuts against the abutting surface, and the parking action ends.

[0030] As one possible implementation manner of the second aspect, before receiving the parking signal, the method further includes:

[0031] Determine whether the voltage signal is within the operating voltage range;

[0032] If it is within the working voltage range, upon receiving the parking signal, the brake driver is controlled to drive the piston forward so that the piston moves from the current position to the braking position;

[0033] If the voltage signal is outside the operating voltage range, a warning signal is issued.

[0034] As one possible implementation manner of the second aspect, the operating voltage range is greater than 9.8V and less than 16V.

[0035] The technical effect of the present invention compared with the prior art is that when the piston is in the braking position, the brake caliper assembly clamps the wheel hub, and because the abutting surface faces away from the brake caliper assembly, the parking plug abuts against the abutting surface, which can play an axial limiting role on the piston, so that the brake caliper assembly maintains the state of clamping the wheel hub, thereby keeping the wheel in the braking state and achieving parking. In this way, the piston is fixed in position by the abutment of the parking plug, thereby improving the control accuracy of the brake caliper assembly, and at the same time, the axial length of the brake caliper assembly will not be increased, saving the layout space in the vehicle.

[0036] The control method of the parking brake system limits the retreat of the piston by pressing the parking plug against the abutting surface when the piston is in the braking position. After parking is completed, the clamping force of the piston on the brake caliper assembly is approximately equal to the pressure applied by the parking plug on the abutting surface. In this way, the piston can always apply a clamping force capable of parking to the brake caliper assembly, and the piston is limited to the braking position after parking is completed. The wheel will not rotate slightly after parking is achieved, thereby improving the control accuracy of parking. At the same time, since the parking plug will apply a certain pressure to the piston when pressing against the abutting surface, the clamping force applied by the piston to the brake caliper assembly can be increased, thereby improving the parking effect. If the vehicle is parked immediately after driving, the brake device is in a high temperature state. At this time, increasing the clamping force of the piston by the parking plug can compensate to a certain extent for the reduction of the braking force that may be caused by thermal decay, and at the same time reduce the energy consumption of the brake drive to achieve the same parking effect. If parking is performed immediately after braking by stepping on the brake pedal, the wear between the brake caliper assembly and the wheel hub can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention 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.

[0038] Figure 1is a three-dimensional structural diagram of a parking brake system provided by an embodiment of the present invention;

[0039] Figure 2 yes Figure 1 A cross-sectional view of the parking brake system at AA;

[0040] Figure 3 yes Figure 1 A cross-sectional view of the parking brake system at BB;

[0041] Figure 4 is a logic diagram of a control method for a parking brake system provided by an embodiment of the present invention;

[0042] Figure 5 is a logic diagram of a method for controlling a parking brake system in a scenario of parking after parking provided by an embodiment of the present invention;

[0043] Figure 6 It is a logic diagram of a control method of a parking brake system in a scenario where a vehicle is parked after the foot is pressed on the brake, provided by an embodiment of the present invention;

[0044] Figure 7 is a logic diagram of a method for controlling a parking brake system in a scenario where a vehicle rolls away after parking is completed, provided by an embodiment of the present invention;

[0045] Figure 8 It is a logic diagram of a control method of a parking brake system in a non-parking scenario provided by an embodiment of the present invention.

[0046] Description of reference numerals:

[0047] 10. Braking device; 11. Caliper body; 111. Gear assembly; 112. Motor housing; 113. Stop pin; 101. Mounting cavity; 1011. First mounting hole; 1012. Second mounting hole; 1013. Opening; 102. Connecting cavity; 103. Transmission cavity; 104. Stop hole; 12. Brake motor; 13. Screw rod; 14. Piston; 140. Abutment surface; 141. Inner ring; 142. Outer ring; 15. Caliper assembly; 161. Flange bearing seat; 162. Intermediate bearing; 163. Pressure sensor; 17. Sealing structure; 18. Dust cover; 191. Caliper frame; 192. Guide pin; 20. Parking device; 21. Parking drive; 211. Parking motor; 212. Threaded shaft; 22. Parking plug; 220. Limiting surface; 221. Stop groove; 23. Sealing ring. DETAILED DESCRIPTION

[0048] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0053] An embodiment of the present invention provides a parking brake system, which is applied to a vehicle. Specifically, the parking brake system is installed at a wheel and is used to brake and park the wheel.

[0054] See also Figure 1 and Figure 2 The parking brake system includes a braking device 10 and a parking device 20.

[0055] The brake device 10 includes a caliper body 11 , a brake driver, a piston 14 and a brake caliper assembly 15 .

[0056] The caliper body 11 is connected to the vehicle body, and the brake drive component may include a brake motor 12 and a screw rod 13. The brake drive component is connected to the caliper body, specifically, it is connected to the caliper body 11 at least through the brake motor 12, and is transmission-connected to the screw rod 13, wherein the transmission connection can be achieved through a gear assembly 111.

[0057] The piston 14 is connected to the screw rod 13 and is slidably connected to the caliper body 11 along the axial direction of the screw rod 13, wherein the caliper body 11 can limit the rotation of the piston 14, and the transmission connection between the piston 14 and the screw rod 13 can be screwed, or connected to the screw rod 13 through balls, in which case the screw rod 13 can be a ball screw pair. The brake motor 12 can drive the screw rod 13 to rotate, so that the piston 14 moves along the axial direction of the screw rod 13 between the braking position and the separation position.

[0058] The piston 14 has two ends in the axial direction of the screw rod 13, one end is close to the wheel, and the other end is far away from the wheel. The brake caliper assembly 15 is connected to the end of the piston 14, specifically connected to the end of the piston 14 close to the wheel. When the piston 14 is in the braking position, the brake caliper assembly 15 can clamp the wheel hub to achieve braking of the wheel. When the piston 14 is in the separation position, the brake caliper assembly 15 is spaced from the wheel hub in the vehicle road to release the braking of the wheel. Specifically, the brake caliper assembly 15 includes a caliper and a brake pad connected to the caliper. The end of the piston 14 is connected to the caliper. When the piston 14 moves toward the braking position, the piston 14 pushes the caliper to move, so that the brake pad moves toward the wheel hub, until the piston 14 moves to the braking position, and the brake pad is against the wheel hub of the wheel.

[0059] The piston 14 has an abutment surface 140 facing away from the brake caliper assembly 15. The abutment surface 140 can be located at the end of the piston 14 away from the wheel, and can also be located at the axial middle of the piston 14.

[0060] The parking device 20 includes a parking drive 21 and a parking plug 22. The parking drive 21 is connected to the caliper body 11, and the parking plug 22 is connected to the output end of the parking drive 21. The parking drive 21 can drive the parking plug 22 to move and abut against the abutment surface 140 when the piston 14 is in the braking position.

[0061] When the piston 14 is in the braking position, the brake caliper assembly 15 clamps the wheel hub. Since the abutting surface 140 faces away from the brake caliper assembly 15, the parking plug 22 abuts against the abutting surface 140, which can play an axial limiting role on the piston 14, so that the brake caliper assembly 15 maintains the state of clamping the wheel hub, thereby keeping the wheel in the braking state and achieving parking. In this way, the piston 14 is fixed in position by the abutment of the parking plug 22, thereby improving the control accuracy of the brake caliper assembly 15, and at the same time, the axial length of the brake caliper assembly 15 will not be increased, saving the layout space in the vehicle.

[0062] When the parking is released, the parking plug 22 can be retracted first to separate from the piston 14, and then the lead screw 13 can be driven to reverse by the brake motor 12 to make the piston 14 retract to the separation position. Before the parking plug 22 is retracted, the lead screw 13 can be driven to rotate forward by the brake motor 12 to increase the force applied by the piston 14 toward the brake caliper assembly 15, so that the force applied by the abutment surface 140 to the parking plug 22 can be reduced. At this time, the parking drive 21 only needs less power to drive the parking plug 22 to separate from the abutment surface 140, which is more energy-saving and improves the reliability of the parking device 20.

[0063] In other embodiments, the brake drive component can be driven by hydraulic pressure, pneumatic pressure or electromagnetic pressure, and there is no limitation here, as long as it can drive the piston to move between the braking position and the release position, and can stay in the braking position after power failure through the limiting effect of the parking plug.

[0064] See also Figure 2 In some embodiments, the caliper body 11 includes a mounting cavity 101, the piston 14 and the parking plug 22 are both arranged in the mounting cavity 101, the cavity wall of the mounting cavity 101 is provided with a through first mounting hole 1011 and a second mounting hole 1012, and an opening 1013 opposite to the first mounting hole 1011, the brake caliper assembly 15 is arranged at the opening 1013, and the piston 14 moves to the braking position by moving toward the opening 1013. The screw rod 13 is arranged in the first mounting hole 1011 and connected to the piston 14, and the parking drive 21 can pass through the second mounting hole 1012 and connect to the parking plug 22. In this way, the caliper body 11 allows the braking device 10 and the parking device 20 to form a whole, which is convenient for assembly, and at the same time realizes the limiting of the parking plug 22. The moving direction of the parking plug 22 can be parallel to the axial direction of the screw rod 13, or it can be at an angle to the axial direction of the screw rod 13. The moving path of the parking plug 22 can be a straight line, a broken line or a curve. There is no limitation here, as long as it can finally abut against the abutment surface 140.

[0065] Optionally, the screw rod 13 and the hole wall of the first mounting hole 1011 are sealed by a sealing structure 17 to prevent the liquid in the mounting cavity 101 from entering the interior of the vehicle through the first mounting hole 1011 and causing a short circuit in the brake motor 12 or other electronic devices.

[0066] Optionally, the brake device 10 further includes a flange bearing seat 161, an intermediate bearing 162 and a pressure sensor 163, all of which are located in the installation cavity 101. The flange bearing seat 161 is connected to the end of the screw rod 13 away from the brake caliper assembly 15. The pressure sensor 163 is connected to the cavity wall of the installation cavity 101 and is close to the first installation hole 1011. The intermediate bearing 162 is clamped between the flange bearing seat 161 and the pressure sensor 163. When the screw rod 13 rotates, the screw rod 13 drives the flange bearing seat 161 to rotate, and the flange bearing seat 161 rotates relative to the pressure sensor 163 through the intermediate bearing 162. The intermediate bearing 162 can reduce the friction between the flange bearing seat 161 and the pressure sensor 163. The intermediate bearing 162 can be selected as a plane bearing or a needle bearing. When the brake motor 12 drives the screw rod 13 to rotate so that the piston 14 moves to the braking position, the pressure sensor 163 can detect the reaction force of the wheel on the brake caliper assembly 15. The reaction force is the force applied by the brake caliper assembly 15 to the wheel hub. In this way, the pressure sensor 163 realizes the detection of the force applied by the brake caliper assembly 15 to the wheel hub.

[0067] Optionally, the piston 14 is adapted to the installation cavity 101 and cooperates with the gap of the cavity wall at the opening 1013 to seal the opening 1013 of the installation cavity 101. A dust cover 18 is arranged between the piston 14 and the caliper. The dust cover 18 is used to prevent dust from entering the installation cavity 101 through the gap between the piston 14 and the cavity wall at the opening 1013.

[0068] Optionally, the caliper body 11 is also connected to a motor housing 112, the motor housing 112 has a connecting cavity 102 and a transmission cavity 103 connected to the connecting cavity 102, the connecting cavity 102 is located on the side of the caliper body 11 in the normal direction of the axis of the installation cavity 101, the brake motor 12 is installed in the connecting cavity 102, the axis of the output shaft of the brake motor 12 is parallel to the axis of the screw rod 13, the gear assembly 111 is arranged in the transmission cavity 103, and the brake motor 12 and the screw rod 13 are connected by transmission through the gear assembly 111. In this way, the setting of the parking motor 211 will not increase the axial length of the braking device 10, thereby saving space in the vehicle.

[0069] Optionally, the caliper body 11 is further connected to a caliper frame 191 , on which a guide pin 192 is provided. The caliper frame 191 is connected to the wheel via the guide pin 192 to limit the brake caliper assembly 15 .

[0070] Optionally, the axis of the first mounting hole 1011 is parallel to the axis of the second mounting hole 1012, and the first mounting hole 1011 and the second mounting hole 1012 are both located on the same side of the mounting cavity 101, so that the brake motor 12 and the parking drive 21 can be arranged side by side on the same side of the caliper body 11 to save space.

[0071] See also Figure 2 In some embodiments, the peripheral side of the piston 14 is formed with a step structure, and the abutting surface 140 forms a table of the step structure. In this way, the parking plug 22 can be arranged near the middle of the piston 14, thereby reducing the axial space occupied by the parking device 20 on the caliper body 11.

[0072] Optionally, the piston 14 includes an inner ring portion 141 and an outer ring portion 142 connected to the inner ring portion 141, the inner ring portion 141 is screwed to the screw rod 13, the outer ring portion 142 is connected to the brake caliper assembly 15, the outer ring surface of the outer ring portion 142 protrudes from the outer ring surface of the inner ring portion 141, and the abutment surface 140 is in contact with the outer ring surface of the outer ring portion 142 and the outer ring surface of the inner ring portion 141. At this time, the abutment surface 140 and the outer ring surface of the outer ring portion 142 form a step structure together, and the abutment surface 140 is arranged around the inner ring portion 141. This structure of the piston 14 is convenient for processing, and at the same time, the position accuracy requirement of the parking plug 22 is relatively low, which facilitates the abutment of the parking plug 22 with the abutment surface 140.

[0073] Optionally, the inner ring portion 141 is sleeved outside the screw rod 13, and the central axis of the outer ring portion 142 coincides with the central axis of the inner ring portion 141, so that the abutment surface 140 is arranged with equal width along the circumference of the inner ring portion 141 to facilitate processing.

[0074] See also Figure 2 In some embodiments, the parking drive 21 can drive the parking plug 22 to move axially along the screw 13. The parking plug 22 has a limiting surface 220 facing the brake caliper assembly 15. The limiting surface 220 and the abutting surface 140 are at least partially staggered in the axial direction of the screw 13. In this way, the parking plug 22 can move toward the brake caliper assembly 15 so that the limiting surface 220 abuts against the abutting surface 140, reducing the space occupied by the caliper body 11 in the normal direction of the axis of the first mounting hole 1011. At the same time, the displacement of the parking plug 22 can be adjusted according to the moving position of the piston 14. When the piston 14 is slightly deformed after long-term use, the parking plug 22 can abut against the abutting surface 140 by increasing the displacement. It should be noted that when the piston 14 is in the disengaged position, the parking plug 22 can be separated from the piston 14 or can be in abutment with the abutment surface 140 to limit the piston 14 when the piston 14 is in the disengaged position. There is no need to set a limiting structure for the piston 14 in the caliper body 11, so as to simplify the structure of the braking device 10 and facilitate processing.

[0075] Optionally, the parking drive member 21 includes a parking motor 211 and a threaded shaft 212 connected to the output end of the parking motor 211, and the parking plug 22 is threadedly connected to the threaded shaft 212 and slidably connected to the caliper body 11 along the axial direction of the threaded shaft 212. The parking motor 211 can drive the threaded shaft 212 to rotate, and when the threaded shaft 212 rotates, the parking plug 22 can be driven to slide along the axial direction of the threaded shaft 212 to achieve contact and separation with the contact surface 140. Among them, when the parking plug 22 abuts against the abutment surface 140, the piston 14 applies an axial force to the parking plug 22. The threaded connection between the parking plug 22 and the threaded shaft 212 can enable the parking plug 22 to achieve self-locking through the friction between the two matching threaded surfaces, thereby preventing the parking plug 22 from shifting under the large force applied by the piston 14, and the parking motor 211 can be directly powered off, without the need for the parking motor 211 to remain in working state to maintain the position of the parking plug 22, thereby saving energy consumption.

[0076] Please combine Figure 3 Optionally, a stop pin 113 is provided on the caliper body 11, and a stop groove 221 extending along the axial direction of the threaded shaft 212 is provided on the peripheral side surface of the parking plug 22, and the stop pin 113 is slidably connected to the stop groove 221. In this way, the parking plug 22 is slidably connected to the caliper body 11 through the cooperation between the stop groove 221 and the stop pin 113, which has a simple structure and low cost.

[0077] Among them, a stop hole 104 can be opened on the caliper body 11. During assembly, the parking plug 22 can be first threadedly connected to the threaded shaft 212, and then the notch of the stop groove 221 can be aligned with the stop hole 104, and then the stop pin 113 can be inserted into the stop hole 104 from the outside and extended into the stop groove 221 to achieve the cooperation between the stop pin 113 and the stop groove 221, which is convenient for assembly.

[0078] Optionally, the threaded shaft 212 is passed through the second mounting hole 1012 , and the parking motor 211 is installed outside the mounting cavity 101 to avoid occupying the inner space of the mounting cavity 101 .

[0079] Optionally, the threaded shaft 212 is rotatably connected to the second mounting hole 1012 via a parking bearing, so that the threaded shaft 212 can reduce the friction between the threaded shaft 212 and the hole wall of the second mounting hole 1012 through the parking bearing, and at the same time achieve axial and radial limiting through the parking bearing.

[0080] Optionally, the parking motor 211 is at least partially accommodated in the second mounting hole 1012, so that the clamp body 11 can limit the parking motor 211 and buffer the vibration of the parking motor 211. Specifically, the second mounting hole 1012 can include an outer hole section and an inner hole section that are sequentially connected in the axial direction, the inner hole section is close to the mounting cavity 101, the width of the outer hole section is greater than the width of the inner hole section, the parking motor 211 is partially accommodated in the outer hole section, the hole wall of the outer hole section abuts against the peripheral side surface of the parking motor 211, and the end face of the parking motor 211 abuts against the step surface between the outer hole section and the inner hole section, so that the outer hole section can achieve axial and radial limiting of the parking motor 211, and the parking bearing is clamped in the inner hole section.

[0081] Optionally, the parking device 20 further includes a sealing ring 23 that is sealed between the parking motor 211 and the hole wall of the second mounting hole 1012. The sealing ring 23 can seal the second mounting hole 1012 to prevent the liquid in the mounting hole from entering the inside of the vehicle through the second mounting hole 1012 and causing a short circuit in the parking motor 211 or other electronic devices.

[0082] The present invention also provides a control method for a parking brake system, and the control method is applied to the parking brake system in the above embodiment.

[0083] like Figure 4 As shown, the control method of the parking brake system includes:

[0084] When a parking signal is received, the brake driving member is controlled to drive the piston forward so that the piston moves from the current position to the braking position.

[0085] Among them, the control of the brake driver can be realized by ECU. After the driver presses the parking button, the parking button can send a parking signal to ECU, and ECU controls the brake driver to perform braking action according to the parking signal. The current position of the above-mentioned piston can be a separation position, or any position between the separation position and the braking position. When the driver does not step on the brake pedal, the piston is in the separation position. At this time, after pressing the parking switch, the piston moves from the separation position to the braking position; when the driver has stepped on the moving pedal, the piston is between the separation position and the braking position. At this time, after pressing the parking switch, the piston moves from the current position between the separation position and the braking position to the braking position.

[0086] It should be noted that when the piston is in the braking position, the piston applies a certain clamping force to the brake caliper assembly to achieve the braking of the wheel by the brake caliper assembly. The above signal sent to the vehicle may also be a parking lever such as a handbrake, which is not limited here.

[0087] After the piston moves to the braking position, the parking drive member is controlled to drive the parking plug forward until the parking plug is tightly pressed against the abutment surface, thereby completing parking.

[0088] The control of the parking drive can be realized by the ECU. After detecting that the piston moves to the braking position, the ECU controls the parking drive to drive forward so that the parking plug moves forward until the parking plug is pressed against the abutment surface. Pressing here means that the parking plug applies a certain pressure to the piston so that the piston can maintain a certain clamping force on the brake caliper assembly, or increase the clamping force.

[0089] Optionally, after the parking plug is pressed against the abutment surface, the ECU can control the parking drive and the brake drive to cut off power at the same time. At this time, the piston is maintained in the braking position under the limiting action of the parking plug, and the clamping force applied by the piston to the brake caliper assembly is maintained or reduced due to the pressure applied by the parking plug, thereby achieving parking.

[0090] When a release signal is received, the parking drive component is controlled to drive the parking plug to retreat so that the parking plug is separated from the abutment surface. After the parking plug is separated from the abutment surface, the brake drive component is controlled to drive the piston to move from the braking position to the separation position to complete the parking release.

[0091] The release signal can be sent by releasing the parking button. After receiving the release signal, the ECU can control the parking drive to drive in reverse, so that the parking plug retreats. After the parking plug retreats to the initial position, the ECU can control the brake drive to drive in reverse, so that the piston moves from the brake position to the separation position. Of course, the piston can also start to retreat before the parking plug retreats to the initial position, or the parking plug and the piston retreat at the same time, as long as the piston is not affected by the parking plug during the retreat process.

[0092] Optionally, if the brake driver and the parking driver are both powered off after parking is completed, the ECU can control the parking driver and the brake driver to be powered on in sequence or synchronously after receiving a release signal, and then control the parking driver and the brake driver to act. The brake driver can be powered on when the piston needs to be retracted, or it can be powered on when the parking plug is retracted.

[0093] The control method of the parking brake system limits the retreat of the piston by pressing the parking plug against the abutting surface when the piston is in the braking position. After parking is completed, the clamping force of the piston on the brake caliper assembly is approximately equal to the pressure applied by the parking plug on the abutting surface. In this way, the piston can always apply a clamping force capable of parking to the brake caliper assembly, and the piston is limited to the braking position after parking is completed. The wheel will not rotate slightly after parking is achieved, thereby improving the control accuracy of parking. At the same time, since the parking plug will apply a certain pressure to the piston when pressing against the abutting surface, the clamping force applied by the piston to the brake caliper assembly can be increased, thereby improving the parking effect. If the vehicle is parked immediately after driving, the brake device is in a high temperature state. At this time, increasing the clamping force of the piston by the parking plug can compensate to a certain extent for the reduction of the braking force that may be caused by thermal decay, and at the same time reduce the energy consumption of the brake drive to achieve the same parking effect. If parking is performed immediately after braking by stepping on the brake pedal, the wear between the brake caliper assembly and the wheel hub can be reduced.

[0094] In some embodiments, when a release signal is received and the parking plug has not been retracted, the brake driver is first controlled to drive the piston to increase the clamping force applied to the brake caliper assembly, and then the parking driver is controlled to drive the parking plug to retract after the clamping force increases. In this way, since the clamping force of the piston on the brake caliper assembly increases, the reaction force applied by the abutment surface to the parking plug is reduced, and since the parking plug is threadedly engaged with the threaded shaft of the parking driver, the friction force between the parking plug and the threaded shaft that needs to be overcome when retracting is reduced, thereby reducing the power of the parking motor when the parking plug retracts, saving energy consumption, and increasing the service life of the parking device.

[0095] The parking plug can be retracted when the clamping force of the piston is greater than the force applied by the parking plug to the abutment surface, so as to avoid the piston from suddenly retracting when the parking plug is retracted, so that the vehicle can maintain the braking state when the parking is released, and ensure that the vehicle remains stable during the retraction of the parking plug. At the same time, it can avoid the piston from being subjected to abnormal impact force due to the excessively fast pressure change of the brake caliper assembly when the parking plug is suddenly retracted, resulting in damage to the piston, the seal inside the brake caliper and other components.

[0096] In some embodiments, if a brake pedal displacement signal is received before a parking signal is received, the brake driver is controlled to output a corresponding braking force according to the brake pedal displacement signal, so that the piston moves from the separation position to the current position. The displacement signal can be obtained by detecting a pedal displacement sensor.

[0097] It can be understood that when the driver steps on the brake pedal, a displacement stroke signal is issued, and the ECU can receive the displacement stroke signal and control the brake drive to drive the piston forward according to the displacement stroke signal. The piston moves to the current position between the separation position and the braking position. Then, after pressing the brake button, the piston can move from the current position toward the braking position. In this way, the parking action can be performed after braking or during braking. The pressure of the parking plug on the piston bracket increases the clamping force applied by the brake caliper assembly to the wheel hub, so as to shorten the braking time, reduce the wear between the brake caliper assembly and the wheel hub, and compensate for the reduction in braking force due to thermal decay. Among them, if the piston has reached the braking position after the brake pedal is stepped on, the ECU can directly control the parking drive to drive the parking plug to press against the abutment surface without controlling the brake drive to act, thereby eliminating the parking step and achieving quick parking.

[0098] In some embodiments, in the above embodiments, the step of controlling the brake driver to drive the piston forward so that the piston moves from the current position to the brake position specifically includes:

[0099] When receiving a parking signal, determine whether the parking slope is less than or equal to 8°;

[0100] If the parking slope is less than or equal to 8°, the brake driver is controlled to drive the piston forward so that the piston moves from the current position to the braking position, and the current of the brake driver reaches the first parking current;

[0101] If the parking slope is greater than 8°, the brake driver is controlled to drive the piston forward so that the piston moves from the current position to the braking position, and the current of the brake driver reaches the second parking current;

[0102] Among them, the second parking current is greater than the first parking current. The greater the current driving the brake drive component, the greater the clamping force applied by the piston to the brake caliper assembly. Therefore, when the parking slope is greater than 8°, the clamping force of the piston is greater than the clamping force of the piston when the parking slope is less than or equal to 8°.

[0103] In this step, the ECU can adjust the current of the brake drive according to the slope of the ground where the vehicle is located. When the slope is small, a smaller first parking current can be used, and when the slope is large, a larger second parking current can be used. In this way, the reliability of parking on a large slope can be guaranteed, and the energy consumption of the brake drive can be reduced on a small slope. The parking slope can be detected by a body posture sensor in the vehicle.

[0104] In some embodiments, in the above embodiments, the step of controlling the parking drive member to drive the parking plug forward until the parking plug is tightly pressed against the abutment surface specifically includes:

[0105] Determine the magnitude of the clamping force applied by the piston toward the brake caliper assembly and the clamping force required for parking;

[0106] When the clamping force is greater than or equal to the parking demand clamping force, the parking drive member is controlled to drive the parking plug forward until the parking plug is pressed against the abutment surface;

[0107] When the clamping force is less than the parking requirement clamping force, the brake drive member is controlled to drive the piston to increase the clamping force until the clamping force is greater than or equal to the parking requirement clamping force, and the parking drive member is controlled to drive the parking plug forward until the parking plug is pressed against the abutment surface.

[0108] The parking demand clamping force is the clamping force that the piston needs to apply to the brake caliper assembly to prevent the vehicle from slipping. The clamping force can be detected by a pressure sensor in the brake device. The pressure sensor can perform real-time detection, so the above process can be repeated multiple times.

[0109] Through the above steps, it can be ensured that after parking is completed, the clamping force of the piston on the brake caliper assembly is always greater than or equal to the parking required clamping force, so as to improve the reliability of parking. Among them, the pressure sensor is always in a detection state, that is, after parking is completed, as long as the clamping force is reduced to the parking required clamping force, the brake drive and the parking drive will be automatically powered on to perform the above steps, thereby improving the stability of long-term parking.

[0110] In some embodiments, after the step of tightening the parking plug onto the abutment surface, the method further includes:

[0111] Determine whether the wheel is rotating;

[0112] If the wheels do not turn, the parking action is complete;

[0113] If the wheel rotates, the brake drive member is controlled to drive the piston forward until the wheel stops rotating, and the parking drive member is controlled to drive the parking plug forward until it is tightly pressed against the abutment surface, and the parking action is completed.

[0114] Whether the wheel is rotating can be detected by a wheel speed sensor, and the wheel speed sensor can perform real-time detection, so the above process can be repeated multiple times.

[0115] In this embodiment, whether the wheel is rotating is used as a criterion for whether to increase the clamping force. If the vehicle is on a horizontal plane or does not slip, there is no need to energize the brake drive and the parking drive even if the clamping force of the piston does not reach the parking requirement. Only when slipping occurs will the brake drive and the parking drive be energized, thereby saving vehicle energy consumption.

[0116] In some embodiments, before receiving the parking signal, the method further includes:

[0117] Determine whether the voltage signal is within the operating voltage range;

[0118] If it is within the working voltage range, when a parking signal is received, the brake drive member is controlled to drive the piston forward so that the piston moves from the current position to the braking position;

[0119] If the voltage signal is outside the operating voltage range, a warning signal is issued.

[0120] The warning signal includes but is not limited to the warning sound emitted by the speaker and the warning light turning on or flashing. The voltage signal can be obtained through the voltage sensor on the vehicle. When the voltage signal is within the working voltage range, it means that the ECU can control the parking device to work normally. When the voltage signal is not within the working voltage range, it means that the ECU is invalid or cannot work normally, and the parking action cannot be completed. At this time, early warning can avoid accidents.

[0121] Optionally, the operating voltage range is greater than 9.8V and less than 16V. Within this operating voltage range, the ECU can normally control the parking drive component to perform parking action.

[0122] Specific implementation methods are listed below according to different scenarios.

[0123] like Figure 5 As shown, in the scenario of parking after stopping, the control method of the parking brake system includes:

[0124] The driver presses the parking button;

[0125] After the driver presses the parking button, the parking signal is sent to the ECU, which receives the parking signal and communicates with the parking brake system;

[0126] After receiving the parking signal, the ECU determines whether the parking slope is less than or equal to 8°;

[0127] If the parking slope is less than or equal to 8°, the brake driver is controlled to drive the piston forward so that the piston moves from the separation position to the braking position, and the current of the brake driver reaches a smaller first parking current;

[0128] If the parking slope is greater than 8°, the brake drive member is controlled to drive the piston forward so that the piston moves from the separation position to the braking position, and the current of the brake drive member reaches a larger second parking current;

[0129] After the piston reaches the braking position and the current of the brake driver reaches the corresponding parking current, the ECU controls the parking driver to drive the parking plug forward until the parking plug is tightly pressed against the abutment surface of the piston;

[0130] After the parking plug is pressed against the abutment surface of the piston, the ECU controls the brake drive component and the parking drive component to cut off power;

[0131] The ECU determines whether a release signal is received;

[0132] If no release signal is received, parking is completed;

[0133] If a release signal is received, the ECU controls the brake driver to be energized so that the brake driver drives the piston in a positive direction until the clamping force of the piston is greater than the force applied by the parking plug to the abutment surface;

[0134] After the clamping force of the piston is greater than the force applied by the parking plug to the abutment surface, the ECU controls the parking drive member to drive the parking plug to retreat;

[0135] After the parking plug returns to the initial position, the ECU controls the brake driver to drive the piston back to the disengaged position to complete the parking release.

[0136] like Figure 6 As shown, in the scenario of parking after the foot is pressed on the brake, the control method of the parking brake system includes:

[0137] The driver presses the brake pedal;

[0138] After the driver steps on the brake pedal, the pedal displacement sensor transmits a displacement stroke signal to the ECU. The ECU controls the brake driver to output a corresponding braking force based on the displacement stroke signal, so that the piston moves from the separation position to the current position.

[0139] After the piston is in the current position, if the driver presses the parking switch, the ECU determines the clamping force applied by the piston toward the brake caliper assembly and the clamping force required for parking;

[0140] When the clamping force is less than the parking requirement clamping force, the ECU controls the brake driver to drive the piston to increase the clamping force until the clamping force is greater than or equal to the parking requirement clamping force;

[0141] When the clamping force is greater than or equal to the parking requirement clamping force, the ECU controls the parking drive to be energized, and causes the parking drive to drive the parking plug forward until the parking plug is pressed against the abutment surface;

[0142] When the parking plug is pressed against the abutment surface, the ECU controls the brake drive component and the parking drive component to cut off power, and parking is completed.

[0143] like Figure 7 As shown, in the scenario where the vehicle slips after parking is completed, the control method of the parking brake system includes:

[0144] The driver stops the car and presses the parking button;

[0145] After the driver presses the parking button, the parking signal is sent to the ECU, and the ECU controls the brake driver to drive the piston forward until the clamping force applied by the piston to the brake caliper assembly is greater than the parking required clamping force;

[0146] After the clamping force applied by the piston to the brake caliper assembly is greater than the parking required clamping force, the ECU controls the parking drive member to drive the parking plug to press against the abutment surface of the piston;

[0147] After the parking plug is pressed against the abutment surface of the piston, the ECU controls the brake drive and the parking drive to cut off power, and parking is completed;

[0148] After parking is completed, the ECU determines whether the wheels are rotating based on the detection results of the wheel speed sensor;

[0149] If the wheels do not rotate, the ECU controls the brake drive and parking drive to cut off power, and parking is completed;

[0150] If the wheel rotates, the ECU controls the brake drive to drive the piston forward until the wheel stops rotating. The ECU controls the parking drive to drive the parking plug forward until the parking plug is tightly pressed against the abutment surface. The ECU controls the brake drive and the parking drive to cut off power, and parking is completed.

[0151] like Figure 8 As shown, in the unparked scenario, the control method of the parking brake system includes:

[0152] The driver drives the vehicle;

[0153] The ECU determines whether the voltage signal is within the operating voltage range after the vehicle is turned on;

[0154] If the voltage signal is within the working voltage range, the ECU enters the parking control program;

[0155] If the voltage signal is outside the working voltage range, parking fails and a warning signal is issued.

[0156] The above descriptions are only some specific embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other specific implementations of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A parking brake system, characterized in that: include: A brake device, comprising a caliper body, a brake driver, a piston and a brake caliper assembly, wherein the brake driver is connected to the caliper body and is drivingly connected to the piston, the brake driver can drive the piston to move along its own axis between a braking position and a release position, the brake caliper assembly is connected to an end of the piston, the piston moves from the release position to the braking position by moving toward the brake caliper assembly, and the piston has an abutment surface facing away from the brake caliper assembly; The parking device comprises a parking drive connected to the caliper body and a parking plug connected to the output end of the parking drive. The parking drive can drive the parking plug to move and abut against the abutment surface when the piston is in the braking position.

2. The parking brake system according to claim 1, characterized in that: The parking drive comprises a parking motor and a threaded shaft connected to the output end of the parking motor, the parking plug is threadedly connected to the threaded shaft and slidably connected to the caliper body along the axial direction of the threaded shaft, wherein the axial direction of the threaded shaft is the same as the axial direction of the piston.

3. A control method for a parking brake system, applied to the parking brake system according to claim 1 or 2, characterized in that: The control method of the parking brake system comprises: When a parking signal is received, the brake driving member is controlled to drive the piston forward so that the piston moves from the current position to the braking position; After the piston moves to the braking position, the parking drive member is controlled to drive the parking plug forward until the parking plug is tightly pressed against the abutting surface, thereby completing parking; When a release signal is received, the parking drive member is controlled to drive the parking plug to retreat so that the parking plug is separated from the abutment surface; After the parking plug is separated from the abutment surface, the brake drive member is controlled to drive the piston to move from the braking position to the separation position to complete the parking release.

4. The control method according to claim 3, characterized in that: When the release signal is received and the parking plug has not retracted, the brake driver is first controlled to drive the piston to increase the clamping force applied toward the brake caliper assembly, and then the parking driver is controlled to drive the parking plug to retract after the clamping force increases.

5. The control method according to claim 3, characterized in that: If a displacement stroke signal of the brake pedal is received before the parking signal is received, the brake driver is controlled to output a corresponding braking force according to the displacement stroke signal of the brake pedal, so that the piston moves from the separation position to the current position.

6. The control method according to claim 3, characterized in that: The controlling the brake driver to drive the piston forward so that the piston moves from the current position to the brake position comprises: When receiving a parking signal, determine whether the parking slope is less than or equal to 8°; If the parking slope is less than or equal to 8°, the brake driver is controlled to drive the piston forward, so that the piston moves from the current position to the braking position, and the current of the brake driver reaches the first parking current; If the parking slope is greater than 8°, the brake driver is controlled to drive the piston forward, so that the piston moves from the current position to the braking position, and the current of the brake driver reaches the second parking current; Wherein, the second parking current is greater than the first parking current.

7. The control method according to claim 3, characterized in that: The step of controlling the parking drive member to drive the parking plug forward until the parking plug abuts against the abutting surface comprises: determining the magnitude of the clamping force applied by the piston toward the brake caliper assembly and the parking demand clamping force; When the clamping force is greater than or equal to the parking requirement clamping force, the parking drive member is controlled to drive the parking plug forward until the parking plug is pressed against the abutment surface; When the clamping force is less than the parking requirement clamping force, the brake drive is controlled to drive the piston to increase the clamping force until the clamping force is greater than or equal to the parking requirement clamping force, and the parking drive is controlled to drive the parking plug forward until the parking plug is pressed against the abutment surface.

8. The control method according to claim 3, characterized in that: After the parking plug is pressed against the abutting surface, the method further comprises: Determine whether the wheel is rotating; If the wheels do not turn, the parking action is complete; If the wheel rotates, the brake driver is controlled to drive the piston forward until the wheel stops rotating, and the parking driver is controlled to drive the parking plug forward until it abuts against the abutting surface, and the parking action ends.

9. The control method according to claim 3, characterized in that: Before receiving the parking signal, the method further includes: Determine whether the voltage signal is within the operating voltage range; If it is within the working voltage range, upon receiving the parking signal, the brake driver is controlled to drive the piston forward so that the piston moves from the current position to the braking position; If the voltage signal is outside the operating voltage range, a warning signal is issued.

10. The control method according to claim 9, characterized in that: The operating voltage range is greater than 9.8V and less than 16V.

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