Electromagnet and EMB parking structure

Abstract

The invention belongs to the technical field of braking, and discloses an electromagnet which is used for an EMB parking structure, the EMB parking structure comprises a motor, a ratchet wheel and a pawl, the electromagnet comprises a frame body, a static magnetic assembly, a movable magnetic core and an elastic piece, the static magnetic assembly is arranged in the frame body, the movable magnetic core penetrates through the frame body and is connected with the pawl, the static magnetic assembly generates force F1 for driving the movable magnetic core to move, and the elastic piece is arranged on the frame body. The F1 changes along with movement of the movable magnetic core, and the elastic piece is used for generating force F2 for driving the first end of the movable magnetic core to extend outwards. When the vehicle is not parked, the movable magnetic core is located at the initial position; when parking is needed, the movable magnetic core extends outwards from the initial position to the parking position through the first position, and the pawl is driven to move and abut against the interior of a tooth groove between every two adjacent ratchets of the ratchet wheel. When the electromagnet is not powered on, the movable magnetic core is located at the first position, F1 is equal to F2, the stroke length of the movable magnetic core from the parking position to the first position is larger than the ratchet height of the ratchet wheel, and the electromagnet can be matched with the motor to achieve the anti-sliding function without being powered on any more.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of braking, in particular to an electromagnet and an EMB parking structure. BACKGROUND

[0002] An electro-mechanical brake (EMB) system is a braking system that uses electrical and mechanical components to slow or stop a vehicle. It uses electric motors or actuators to apply the brakes, effectively replacing the hydraulic drive of traditional brakes, and is more accurate in control, improves braking performance, reduces the setting of hydraulic components, and is more stable and easier to maintain.

[0003] The EMB parking structure in the prior art is mostly realized by an electromagnet driving a ratchet and pawl structure. Specifically, the electromagnet is in a bistable or monostable state, but given the principle of the stable-state electromagnet and some additional functions of the parking, such as high-temperature re-clamping and rolling re-clamping, the electromagnet needs to be powered on and off again to achieve these functions. If the electromagnet maintains insufficient force during the power-off process, the electromagnet will fail, and in severe cases, it will pose a risk of rolling. SUMMARY

[0004] The purpose of the present application is to provide an electromagnet that effectively increases the holding force of the electromagnet in a certain stroke after power-off, without the need to power on the electromagnet again, to achieve the anti-rolling function in cooperation with the motor, and the use effect is reliable and stable.

[0005] To achieve this purpose, the present application adopts the following technical solutions:

[0006] An electromagnet for an EMB parking structure, the EMB parking structure comprising a motor, a ratchet connected to the motor, and a pawl cooperating with the ratchet, the electromagnet comprising a frame body, a static magnetic assembly, a dynamic magnetic core, and an elastic member; wherein,

[0007] The static magnetic assembly is arranged in the frame body, the dynamic magnetic core is arranged through the frame body, the first end of the dynamic magnetic core is connected to the pawl, and the elastic member is arranged between the frame body and the dynamic magnetic core. The static magnetic assembly is used to generate a force F1 that drives the dynamic magnetic core to move, and F1 changes with the movement of the dynamic magnetic core. The elastic member is used to generate a force F2 that drives the first end of the dynamic magnetic core to extend outward.

[0008] When not parked, the dynamic magnetic core is in an initial position.

[0009] When parking is needed, the electromagnet is powered to drive the moving magnetic core to extend from the initial position to the parking position via a first position, and drive the pawl to move and be clamped in a tooth slot between two teeth of the ratchet wheel; when the electromagnet is not powered and the moving magnetic core is at the first position, F1=F2, the stroke length S1 of the moving magnetic core from the parking position to the first position is greater than the tooth height H of the ratchet wheel.

[0010] As preferably, when the moving magnetic core is at the parking position, the continued rotation of the motor can drive the ratchet wheel to rotate relative to the pawl, so that the pawl moves out of the current tooth slot and is clamped in the next adjacent tooth slot, and the stroke length of the moving magnetic core corresponding to the current tooth slot is less than or equal to the stroke length S1 of the moving magnetic core between the first position and the parking position.

[0011] As preferably, when the electromagnet is not powered, the position of the moving magnetic core where the magnetic force of the static magnetic assembly is 0 is a second position, the position of the moving magnetic core where the rotation of the motor drives the ratchet wheel to rotate relative to the pawl is a third position, the stroke length between the second position and the parking position is S2, and the stroke length between the third position and the parking position is S3; then S2<S3<S1.

[0012] As preferably, the static magnetic assembly comprises a coil arranged on the frame body; wherein,

[0013] The coil is powered to drive the moving magnetic core to move from the initial position to the parking position; and the coil is powered in the opposite direction to drive the moving magnetic core to move from the parking position to the initial position.

[0014] As preferably, the static magnetic assembly comprises a first static magnetic core, a second static magnetic core and a magnetic member; wherein,

[0015] The first static magnetic core, the second static magnetic core and the magnetic member can all generate magnetic force on the moving magnetic core, the first static magnetic core is attracted to the moving magnetic core when the moving magnetic core is at the parking position, and the second static magnetic core is attracted to the moving magnetic core when the moving magnetic core is at the initial position.

[0016] As preferably, the frame body is provided with a through hole extending from a first end to a second end, the first static magnetic core is arranged at the first end of the through hole, the second static magnetic core is arranged at the second end of the through hole, the first end of the moving magnetic core penetrates through the first static magnetic core, and the second end of the moving magnetic core penetrates through the second static magnetic core.

[0017] As preferably, the moving magnetic core comprises a first core part, a second core part and a third core part arranged in sequence, the diameter of the second core part is greater than that of the first core part and the third core part, the first static magnetic core is provided with a first hole, the second static magnetic core is provided with a second hole, the first core part is slidably arranged in the first hole, the second core part is slidably arranged in the through hole, the third core part is slidably arranged in the second hole, and the distance between the first static magnetic core and the second static magnetic core is greater than the length of the second core part.

[0018] As preferably, the first end of the moving magnetic core is provided with a plug, the plug is provided with a first hinge shaft, the pawl is provided with a first hinge hole corresponding, the first hinge hole is provided as a long hole, the first hinge shaft can be hinged with the first hinge hole and can move along the length direction of the first hinge hole.

[0019] As preferably, the elastic member is provided as a spring, the spring is sleeved on the moving magnetic core and the plug.

[0020] As preferably, the first end of the frame body is provided with a first baffle, the plug is provided with a second baffle, the first end of the spring abuts against the first baffle, and the second end abuts against the second baffle.

[0021] Beneficial effects:

[0022] The electromagnet provided by the application, the static magnetic assembly generates a force F1 for driving the moving magnetic core to move, the value of F1 changes with the movement of the moving magnetic core, the elastic member generates a force F2 for driving the first end of the moving magnetic core to extend out, and the resultant force of F1 and F2 is the resultant force acting on the moving magnetic core when the electromagnet is not powered. When not parking, the moving magnetic core is located at the initial position, at this time, the pawl is separated from the ratchet wheel and is in the parking release state. When parking is needed, the electromagnet is powered in the forward direction, the moving magnetic core is driven to extend out from the initial position and pass through the first position to the parking position, the pawl is driven to move and is clamped in the tooth groove between the two teeth of the ratchet wheel, at this time, the pawl is engaged with the ratchet wheel and is in the parking state. When the parking is completed and the electromagnet stops being powered for a period of time, the clamping force of the wheel end gradually decreases due to the continuous temperature drop of the wheel end friction plate and the jaw assembly and other components. When the clamping force of the wheel end decreases to a certain value, the vehicle may have a risk of rolling. In order to prevent the vehicle from rolling, the motor can be controlled to increase the clamping force according to the program control after the parking is performed for a period of time. However, the electromagnet is not powered during the process, and the pawl and the ratchet wheel cannot be separated. When the moving magnetic core moves from the parking position to the first position, F1=F2, and the stroke length S1 of the moving magnetic core from the parking position to the first position is greater than the tooth height H of the ratchet wheel. Even if the moving magnetic core moves by the stroke length H, that is, by the height of one tooth, the resultant force of the moving magnetic core is always greater than 0, so that the elastic member can always provide a positive holding force. The electromagnet does not need to be powered again to realize the anti-rolling function in cooperation with the motor, improve the adverse effects of accidental failure of the electromagnet after power failure, and is reliable and stable in use. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic diagram of the electromagnet provided by the application;

[0024] Figure 2 is an explosion schematic diagram of the electromagnet provided by the application;

[0025] Figure 3 is a cross-sectional schematic diagram of the electromagnet provided by the application, in which the moving magnetic core does not extend out;

[0026] Figure 4 is a cross-sectional schematic diagram of the electromagnet provided by the application, in which the moving magnetic core extends out;

[0027] Figure 5 is an internal structure schematic diagram of the EMB parking structure provided by the application;

[0028] Figure 6 is a main component structure schematic diagram of the EMB parking structure provided by the application;

[0029] Figure 7 is an explosion schematic diagram of the main components of the EMB parking structure provided by the application;

[0030] Figure 8is the main part profile schematic view of the EMB parking structure provided by the application;

[0031] Figure 9 is the schematic view of the main part of the EMB parking structure provided by the application when not parking;

[0032] Figure 10 is the schematic view of the main part of the EMB parking structure provided by the application when parking;

[0033] Figure 11 is the local enlarged schematic view of A in the application Figure 10

[0034] Figure 12 is the schematic view of the main part of the EMB parking structure provided by the application when parking at high temperature or during the process of slipping and clamping again;

[0035] Figure 13 is the schematic view of the force value on the moving magnetic core of the electromagnet changing with stroke provided by the application.

[0036] in the figure:

[0037] 1, frame body; 11, through hole; 12, first baffle; 13, embedding groove;

[0038] 21, first static magnetic core; 211, first hole; 22, second static magnetic core; 221, second hole; 23, magnetic member; 24, coil;

[0039] 3, moving magnetic core; 31, first core part; 32, second core part; 33, third core part; 34, plug; 341, second baffle; 35, first hinge shaft;

[0040] 4, elastic member;

[0041] 5, shell; 51, first gear; 52, second gear; 53, third gear;

[0042] 6, motor; 61, second hinge shaft;

[0043] 7, ratchet wheel;

[0044] 8, pawl; 81, first hinge hole; 82, second hinge hole. DETAILED DESCRIPTION

[0045] The technical solutions of the application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0046] ​In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and moreover, the "above", "over" and "on" of the first feature to the second feature include the first feature directly above and obliquely above the second feature, or only indicate that the first feature is higher in horizontal height than the second feature. The "below", "under" and "under" of the first feature to the second feature include the first feature directly below and obliquely below the second feature, or only indicate that the first feature is lower in horizontal height than the second feature.

[0047] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation on the present application.

[0049] The present application provides an EMB parking structure. Referring to Figures 1 to 13 As shown in the figure, the EMB parking structure includes a motor 6, a ratchet wheel 7 connected with the motor 6, and a pawl 8 matched with the ratchet wheel 7. The EMB parking structure further includes a housing 5 and a jaw assembly (not shown), and the motor 6, the ratchet wheel 7 and the pawl 8 are all arranged in the housing 5.

[0050] The present invention also provides an electromagnet for the above-mentioned EMB parking structure. The electromagnet includes a frame 1, a static magnetic assembly, a moving magnetic core 3, and an elastic element 4. The static magnetic assembly is disposed inside the frame 1, the moving magnetic core 3 is disposed through the frame 1, the first end of the moving magnetic core 3 is connected to a pawl 8, and the elastic element 4 abuts between the frame 1 and the moving magnetic core 3. The static magnetic assembly is used to generate a force F1 to drive the moving magnetic core 3 to move, and F1 changes as the moving magnetic core 3 moves. The elastic element 4 is used to generate a force F2 to drive the first end of the moving magnetic core 3 to extend outward. When the vehicle is not parked, the moving magnetic core 3 is in the initial position. When parking is required, the electromagnet is powered in the positive direction, causing the moving magnetic core 3 to extend from the initial position and pass through the first position to the parking position, which drives the pawl 8 to move and engage in the groove between the two ratchet teeth of the ratchet 7. When the electromagnet is not powered and the moving magnetic core 3 is in the first position, F1=F2, and the stroke length S1 of the moving magnetic core 3 from the parking position to the first position is greater than the ratchet tooth height H of the ratchet 7.

[0051] In this embodiment, the static magnetic component generates a force F1 that drives the moving magnetic core 3 to move. The value of F1 changes as the moving magnetic core 3 moves. The elastic element 4 generates a force F2 that drives the first end of the moving magnetic core 3 to extend outward. When the electromagnet is not energized, the resultant force of F1 and F2 is the resultant force on the moving magnetic core 3. When not parked, the moving magnetic core 3 is in the initial position, at which time the pawl 8 is separated from the ratchet 7, and it is in the parking released state. When parking is required, the electromagnet is positively energized, driving the moving magnetic core 3 to extend outward from the initial position and through the first position to the parking position, causing the pawl 8 to move and engage in the tooth groove between the two ratchet teeth of the ratchet 7. At this time, the pawl 8 is engaged with the ratchet 7, and it is in the parking state. When parking is completed, the electromagnet is de-energized, and the resultant force of F1 and F2, that is, the resultant force on the moving magnetic core 3, drives the moving magnetic core 3 to remain extended. After parking is completed and the electromagnet is de-energized for a period of time, the clamping force at the wheel end will gradually decrease due to the continuous drop in temperature of components such as the wheel end friction plate and the clamp body assembly. When the clamping force at the wheel end drops to a certain value, the vehicle may roll away. To prevent this, after parking for a period of time, the motor 6 can be activated according to the program to increase the clamping force. During this process, the electromagnet is not energized, and it is necessary to ensure that the pawl 8 and the ratchet 7 do not disengage. The moving magnetic core 3 moves from the parking position to the initial position, that is, the moving magnetic core 3 retracts. During this process, it passes through the first position. When the moving magnetic core 3 is in the first position, F1=F2, and the travel length S1 of the moving magnetic core 3 from the parking position to the first position is set to be greater than the ratchet tooth height H of the ratchet 7. Even if the moving magnetic core 3 moves a stroke length H from the parking position, that is, moves the height of one ratchet, the resultant force of the moving magnetic core 3 is always greater than 0. Thus, the elastic element 4 can always provide a positive holding force. The electromagnet can work with the motor 6 to achieve the anti-rollover function without energizing it, improving the adverse effect of the electromagnet failing unexpectedly when the power is cut off, and making it reliable and stable in use.

[0052] The EMB parking structure provided by this invention includes the aforementioned electromagnet. The EMB parking structure has a function of re-clamping the vehicle after it has slipped, eliminating the need to energize the electromagnet. The motor 6 can directly rotate in the pressure-building direction to increase the pressure, resulting in a reliable and stable effect.

[0053] For example, before the moving magnetic core 3 moves from the parking position to the first position, the resultant force of the moving magnetic core 3 is always greater than 0. Since the resultant force of the moving magnetic core is greater than 0, the moving magnetic core 3 will always have an outward extension tendency, causing the pawl 8 to have a tendency to approach and engage with the tooth groove of the ratchet 7.

[0054] In this embodiment, when the moving magnetic core 3 is in the parking position, the motor 6 continues to rotate, driving the ratchet 7 to rotate relative to the pawl 8. This causes the pawl 8 to move out of the current tooth slot and engage in the next adjacent tooth slot. The stroke length of the moving magnetic core 3 corresponding to the pawl 8 moving out of the current tooth slot is less than or equal to the stroke length S1 of the moving magnetic core 3 between the first position and the parking position. This configuration ensures that when the pawl 8 moves out of the current tooth slot, the resultant force of the moving magnetic core remains greater than 0, and the elastic element 4 stably provides a positive holding force.

[0055] Furthermore, when the electromagnet is not energized, the second position is when the magnetic force on the moving magnetic core 3 from the static magnetic component is zero. The third position is when the motor 6 rotates, driving the ratchet 7 to rotate relative to the pawl 8 until the pawl 8 moves out of the current tooth slot, corresponding to the position of the moving magnetic core 3. The travel length between the second position and the parking position is S2, and the travel length between the third position and the parking position is S3; therefore, S2 < S3 < S1. Specifically, the travel lengths S2 and S3 between the second and parking positions are both less than S1, and the resultant force of the moving magnetic core is always a positive holding force. Specifically, when the moving magnetic core 3 is between the parking position and the second position, the magnetic force on the moving magnetic core 3 from the static magnetic component is always greater than zero; when the moving magnetic core 3 is between the second position and the initial position, the magnetic force on the moving magnetic core 3 from the static magnetic component is always less than zero.

[0056] In this embodiment, the electromagnet also includes a coil 24 wound on the frame 1. When the coil 24 is positively energized, it drives the moving magnetic core 3 from the initial position to the parking position; when the coil 24 is negatively energized, it drives the moving magnetic core 3 from the parking position to the initial position. Specifically, when the coil 24 is energized in different directions, it can drive the moving magnetic core 3 to reciprocate between the initial position and the parking position.

[0057] In this embodiment, the static magnetic assembly includes a first static magnetic core 21, a second static magnetic core 22, and a magnetic element 23; wherein,

[0058] The first stationary magnetic core 21, the second stationary magnetic core 22, and the magnetic element 23 can all generate magnetic force on the moving magnetic core 3. When the moving magnetic core 3 is in the parking position, the first stationary magnetic core 21 and the moving magnetic core 3 are attracted together; when the moving magnetic core 3 is in the initial position, the second stationary magnetic core 22 and the moving magnetic core 3 are attracted together. Specifically, as the moving magnetic core 3 moves relative to the magnetic element 23, that is, as the moving magnetic core 3 moves between the first stationary magnetic core 21 and the second stationary magnetic core 22, the magnitude of F1 changes with the movement of the moving magnetic core 3.

[0059] Specifically, when the vehicle is not parked, the moving magnetic core 3 and the second stationary magnetic core 22 are attracted to each other, with their relative positions referenced. Figure 3 As shown. At this time, the magnetic force F1 on the moving magnetic core 3 is generated by the magnetic component 23. In addition, under the action of the elastic component 4, the elastic component 4 generates an elastic force F2 on the moving magnetic core 3 towards the first end of the frame 1, that is, the moving magnetic core 3 extends outward. Therefore, the resultant force F3 received by the moving magnetic core 3 at this time is specifically: F3 = F1 - F2.

[0060] When parking is required, a positive current is input to the PIN pin at the end of coil 24. The current is transmitted to coil 24, generating an electromagnetic force F4 that causes the moving magnetic core 3 to move towards the first end of the frame 1, extending the moving magnetic core 3 outwards. This force increases with the increase of the current. When F4 > F3, the electromagnetic force will drive the moving magnetic core 3 to extend outwards to the parking position. At this time, the current value is defined as I1. Considering some deviation fluctuations, the control current of coil 24 is defined as I2, where I2 = I1 + current margin. When a positive current I2 flows through the two ends of coil 24, the outward extension force F5 on the moving magnetic core 3 is F4 - F1 + F2.

[0061] When the electromagnet reaches the parking position, the moving magnetic core 3 attracts the first stationary magnetic core 21. The magnetic force generated by the magnetic component 23 pushes the moving magnetic core 3 to attract the first stationary magnetic core 21. At this time, the magnetic force of the magnetic component 23 is F1'. Then, when the current on the coil 24 is not disconnected, the electromagnetic force F4' generated by the coil 24 on the moving magnetic core 3, and the extension force of the elastic component 4 is F2'. At this time, the holding force on the moving magnetic core 3 is F5' = F4' + F1' + F2'. After determining that parking is successful, the current across the coil 24 is disconnected. At this time, the electromagnetic force F4' drops to 0, and the extension holding force on the moving magnetic core 3 is F5'' = F1' + F2'. The magnitude of this force F5'' can be defined through simulation and related high and low temperature vibration durability tests of the system. At this time, the position of the moving magnetic core 3 is as follows: Figure 4As shown. When a parking release command is received, a reverse current is applied to the two ends of coil 24. At this time, coil 24 will generate a reverse electromagnetic force F4'' on the moving magnetic core 3. When F4'' > F5'', the moving magnetic core 3 moves towards the second end of the frame 1, i.e., in the retraction direction. The current value at this time is defined as I1'. Considering some deviation fluctuations, the control current of coil 24 is defined as I2', I2' = I1' + current margin. When a reverse current I2' is applied to the two ends of coil 24, the retraction force F6 on the moving magnetic core 3 is F4'' - F1' - F2'. When the moving magnetic core 3 is attracted to the second stationary magnetic core 22, refer to... Figure 3 As shown, the retraction force F6' = F4'' + F1 - F2 at this point, and the holding force after power failure is F3 = F1 - F2 in the initial unparked state. The magnitude of this force F3 can be defined through simulation and related high and low temperature vibration durability tests of the system. The force change of the moving magnetic core 3 on the electromagnet is as follows: Figure 13 As shown in the diagram. S1 represents the stroke of the moving magnetic core 3 when the electromagnet is not energized, retracting inward from the parking position to a total force value of 0, i.e., F3 = F2 - F1 = 0. This is also the stroke of the moving magnetic core 3 between the parking position and the first position. When the retraction stroke of the moving magnetic core 3 does not exceed S1 and F3 > 0, the moving magnetic core 3 will continue to extend outward. When the retraction stroke of the moving magnetic core 3 exceeds S1 and F3 < 0, the moving magnetic core 3 will continue to retract. S2 is the stroke of the moving magnetic core 3 between the position where the magnetic force from the static magnetic component is 0 and the parking position, i.e., the stroke length between the parking position and the second position. S3 is the stroke of the moving magnetic core 3 between the position where the motor 6 rotates to drive the ratchet 7 to rotate relative to the pawl 8 until the pawl 8 moves out of the current tooth slot, and the parking position, i.e., the stroke length between the parking position and the third position.

[0062] Reference Figures 5 to 12 As shown, Figure 5 This is a schematic diagram of the transmission structure of the EMB parking mechanism. The motor 6 is mounted on the housing 5, and a ratchet 7 is press-fitted onto the motor 6. The motor 6 is connected to the caliper assembly. During operation, the motor 6 shaft transmits rotation to the caliper assembly, driving the caliper to travel and clamping force. The diagram illustrates a clockwise increase in clamping force (there are also structures that increase force counterclockwise; the clockwise and counterclockwise descriptions in this invention are only for the currently shown structure and do not represent a specific definition of direction). Specifically, when parking, the pawl 8 rotates clockwise towards the ratchet teeth of the ratchet 7 until the pawl 8 engages with the ratchet teeth of the ratchet 7. Figure 10The diagram illustrates the engagement of pawl 8 with ratchet 7 when the vehicle is parked. Pawl 8 engages with the ratchet teeth, which have uneven angles on both sides, creating an inclined tooth shape. After engagement, pawl 8 cannot rotate counter-clockwise, but clockwise, the torque can still push it to rotate. When the parking brake is released, pawl 8 rotates counter-clockwise, moving away from the ratchet teeth of ratchet 7, until it disengages and returns to its initial engaged state. Figure 9 The image shows the position of pawl 8 relative to ratchet 7 after the parking brake is released.

[0063] Furthermore, upon receiving a parking command, motor 6 rotates. When the clamping force of the clamp assembly reaches the target parking force, a positive current is supplied to both ends of the electromagnet via an external control element. The moving magnetic core 3 of the electromagnet extends outward under the action of electromagnetic force, driving the pawl 8 to rotate and engaging the ratchet teeth, thus parking. Then, the current to both ends of the electromagnet is disconnected, and the electromagnet enters the parking holding state. At this time, the parking extension holding force of the electromagnet is F5''. Upon receiving a parking release command, a reverse current is supplied to both ends of the electromagnet via an external control element. The moving magnetic core 3 tends to retract under the action of electromagnetic force, but due to the meshing structure of the ratchet 7 and the pawl 8, the pawl 8 cannot directly pull out the ratchet teeth of the ratchet 7. At this time, the external control element controls motor 6 to rotate clockwise by a certain angle, so that the pawl 8 and the ratchet 7 rotate to a relative angle where they can disengage. Then, under the action of the retraction force of the moving magnetic core 3 of the electromagnet, the pawl 8 rotates in the opposite direction and disengages from the ratchet. Then, under the action of the retraction force, the moving magnetic core 3 moves toward the second end of the frame 1 and returns to the retracted state, maintaining the attraction force F3, thus realizing the parking release.

[0064] Furthermore, if the wheel end friction pads and brake discs are very hot when the parking command is executed and the vehicle is correctly parked, the wheel end clamping force will decrease as the temperature drops after a period of time. When the wheel end clamping force drops to a certain value, the vehicle may roll away. Therefore, to avoid this rolling away, when a high parking temperature is detected, exceeding the set threshold, the high-temperature re-clamping command needs to be activated. After a certain period of time following the parking command, motor 6 is controlled to rotate clockwise again to increase the clamping force. During the clockwise rotation of motor 6, the pawl 8 is pushed out of the ratchet teeth. Figure 12 As shown, at this time, the pawl 8 will push the moving magnetic core 3 to move a certain distance from the parking position, such as... Figure 13As shown, as long as the length of this stroke is less than S1, the moving magnetic core 3 still has a certain parking extension force, pushing the pawl 8 to press against the surface of the ratchet. After the motor 6 rotates through a certain angle, the pawl 8 will enter the next tooth slot of the ratchet 7 under the action of the pushing force of the moving magnetic core 3, continuing to restrict the retraction of the motor 6. The rotation angle of the motor 6 is calculated by combining the required increase in clamping force and the angle corresponding to the rotation of one ratchet tooth of the ratchet 7. During this process, the electromagnet is always in a de-energized state, and the external control components do not need to energize the electromagnet again to control its action, which can avoid parking failure caused by the electromagnet being re-energized, thus improving reliability. When the parking slope or other environmental changes are detected within a certain period of time, resulting in insufficient parking force, the slippage re-clamping function needs to be activated, controlling the motor 6 to rotate clockwise to increase the parking clamping force. The slippage re-clamping process is similar to high-temperature re-clamping.

[0065] In this embodiment, the frame 1 has a through hole 11 extending from its first end to its second end. The first static magnetic core 21 is disposed at the first end of the through hole 11, and the second static magnetic core 22 is disposed at the second end of the through hole 11. The first static magnetic core 21 passes through the first end of the moving magnetic core 3, and the second static magnetic core 22 passes through the second end of the moving magnetic core 3.

[0066] More specifically, the moving magnetic core 3 includes a first core 31, a second core 32, and a third core 33 arranged sequentially. The diameter of the second core 32 is larger than the diameters of the first core 31 and the third core 33. The first stationary magnetic core 21 has a first hole 211, and the second stationary magnetic core 22 has a second hole 221. The first core 31 slides through the first hole 211, the second core 32 slides within the through hole 11, and the third core 33 slides through the second hole 221. The distance between the first stationary magnetic core 21 and the second stationary magnetic core 22 is greater than the length of the second core 32. Specifically, the moving magnetic core 3 is designed as a structure that is thicker in the middle and thinner at both ends. The first core 31 and the second core 32 are respectively fitted with the first stationary magnetic core 21 and the second stationary magnetic core 22. The first stationary magnetic core 21 and the second stationary magnetic core 22 form a limiting fit at both ends of the moving magnetic core 3, ensuring a reasonable range of movement and extension of the moving magnetic core 3. In addition, the distance between the first static magnetic core 21 and the second static magnetic core 22 is A, and the length of the second core 32 is B. AB is the range of movement of the moving magnetic core 3 as it extends and retracts.

[0067] For example, the first core 31, the second core 32 and the third core 33 are integrally formed.

[0068] Specifically, the first end of the moving magnetic core 3 is provided with a connector 34, and the connector 34 is provided with a first hinge shaft 35. The pawl 8 is correspondingly provided with a first hinge hole 81. The first hinge hole 81 is set as an elongated hole. The first hinge shaft 35 can be hinged with the first hinge hole 81 and can move along the length direction of the first hinge hole 81. In this embodiment, the first hinge hole 81 is set as an elongated hole. In addition to realizing the hinge function, the first hinge shaft 35 can also slide within the first hinge hole 81, thereby realizing the relative position change between the pawl 8 and the moving magnetic core 3, avoiding jamming between the pawl 8 and the moving magnetic core 3, and ensuring the smooth operation of the moving magnetic core 3 and the pawl 8.

[0069] Furthermore, the motor 6 housing is provided with a second hinge shaft 61, and the pawl 8 is provided with a corresponding second hinge hole 82. The second hinge shaft 61 is rotatably inserted through the second hinge hole 82, and the hinge between the pawl 8 and the motor 6 housing, i.e. the outer shell 5, is realized through the second hinge shaft 61.

[0070] In this embodiment, the elastic element 4 is configured as a spring, which is sleeved on the moving magnetic core 3 and the connector 34. Specifically, the two opposite ends of the spring abut against the frame 1 and the connector 34, respectively, thereby applying an elastic force to the moving magnetic core 3. Specifically, the frame 1 has a first baffle 12 at its first end, and the connector 34 has a second baffle 341. The first end of the spring abuts against the first baffle 12, and the second end abuts against the second baffle 341. Specifically, the elastic element 4 is located at the first end of the frame 1, that is, the end of the moving magnetic core 3 that extends outward.

[0071] In this embodiment, the frame 1 has a groove 13, and the magnetic component 23 is embedded in the groove 13. Specifically, the groove 13 is an annular groove, and the magnetic component 23 is an annular structure and is fixedly embedded in the annular groove 13.

[0072] In this embodiment, the first static magnetic core 21, the second static magnetic core 22, the magnetic component 23, and the moving magnetic core 3 are all made of magnets. This provides reliable magnetism, is inexpensive, and is easy to manufacture.

[0073] In this embodiment, the outer casing 5 is provided with a first gear 51, a second gear 52 and a third gear 53. The first gear 51 is fixedly sleeved on the output shaft of the motor 6, the second gear 52 is rotatably connected to the outer casing 5, and the third gear 53 is connected to the planetary gear of the clamp assembly. The first gear 51 is meshed with the second gear 52, and the second gear 52 is meshed with the third gear 53.

[0074] Specifically, a first gear 51, a second gear 52, and a third gear 53 are provided between the motor 6 and the planetary gears of the clamp assembly. When the output shaft of the motor 6 rotates, it sequentially drives the first gear 51, the second gear 52, and the third gear 53 to rotate, which in turn drives the planetary gears of the clamp assembly, which in turn drives the ball screw structure, pushes the friction plate, and generates a clamping force on the wheel.

[0075] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electromagnet for an EMB parking structure, the EMB parking structure comprising a motor (6), a ratchet (7) connected to the motor (6), and a pawl (8) cooperating with the ratchet (7), characterized in that, The electromagnet includes a frame (1), a static magnetic assembly, a moving magnetic core (3), and an elastic element (4); wherein, The static magnetic component is disposed inside the frame (1), the moving magnetic core (3) is disposed through the frame (1), the first end of the moving magnetic core (3) is connected to the pawl (8), the elastic element (4) abuts between the frame (1) and the moving magnetic core (3), the static magnetic component is used to generate a force F1 to drive the moving magnetic core (3) to move, F1 changes with the movement of the moving magnetic core (3), and the elastic element (4) is used to generate a force F2 to drive the first end of the moving magnetic core (3) to extend outward; When the vehicle is not parked, the moving magnetic core (3) is in its initial position; When parking is required, the electromagnet is powered in the positive direction, causing the moving magnetic core (3) to extend from the initial position and through the first position to the parking position, which drives the pawl (8) to move and engage in the groove between the two ratchet teeth of the ratchet (7); when the electromagnet is not powered and the moving magnetic core (3) is in the first position, F1=F2, and the stroke length S1 of the moving magnetic core (3) from the parking position to the first position is greater than the ratchet tooth height H of the ratchet (7).

2. The electromagnet according to claim 1, characterized in that, When the moving magnetic core (3) is in the parking position, the motor (6) continues to rotate, which can drive the ratchet (7) to rotate relative to the pawl (8), so that the pawl (8) moves out of the current tooth groove and is engaged in the next adjacent tooth groove, and the stroke length of the moving magnetic core (3) corresponding to the current tooth groove is less than or equal to the stroke length S1 of the moving magnetic core (3) between the first position and the parking position.

3. The electromagnet according to claim 1, characterized in that, When the electromagnet is not energized, the position where the magnetic force of the moving magnetic core (3) is 0 from the static magnetic component is the second position. The rotation of the motor (6) drives the ratchet (7) to rotate relative to the pawl (8) until the pawl (8) moves out of the position of the moving magnetic core (3) corresponding to the current tooth groove, which is the third position. The travel length between the second position and the parking position is S2, and the travel length between the third position and the parking position is S3; then S2 < S3 < S1.

4. The electromagnet according to claim 1, characterized in that, It also includes a coil (24) wound on the frame (1); wherein, When the coil (24) is energized in the positive direction, it can drive the moving magnetic core (3) to move from the initial position to the parking position; when the coil (24) is energized in the negative direction, it can drive the moving magnetic core (3) to move from the parking position to the initial position.

5. The electromagnet according to claim 1, characterized in that, The static magnetic assembly includes a first static magnetic core (21), a second static magnetic core (22), and a magnetic component (23); wherein, The first static magnetic core (21), the second static magnetic core (22) and the magnetic component (23) can all generate magnetic force on the moving magnetic core (3). When the moving magnetic core (3) is in the parking position, the first static magnetic core (21) attracts the moving magnetic core (3); when the moving magnetic core (3) is in the initial position, the second static magnetic core (22) attracts the moving magnetic core (3).

6. The electromagnet according to claim 5, characterized in that, The frame (1) has a through hole (11) extending from its first end to its second end. The first static magnetic core (21) is located at the first end of the through hole (11), and the second static magnetic core (22) is located at the second end of the through hole (11). The first static magnetic core (21) passes through the first end of the moving magnetic core (3), and the second static magnetic core (22) passes through the second end of the moving magnetic core (3).

7. The electromagnet according to claim 6, characterized in that, The moving magnetic core (3) includes a first core (31), a second core (32) and a third core (33) arranged in sequence. The diameter of the second core (32) is larger than the diameters of the first core (31) and the third core (33). The first static magnetic core (21) has a first hole (211) and the second static magnetic core (22) has a second hole (221). The first core (31) slides through the first hole (211), the second core (32) slides in the through hole (11), and the third core (33) slides through the second hole (221). The distance between the first static magnetic core (21) and the second static magnetic core (22) is greater than the length of the second core (32).

8. The electromagnet according to claim 1, characterized in that, The first end of the moving magnetic core (3) is provided with a connector (34), the connector (34) is provided with a first hinge shaft (35), the pawl (8) is provided with a first hinge hole (81), the first hinge hole (81) is set as an elongated hole, the first hinge shaft (35) can be hinged with the first hinge hole (81) and can move along the length direction of the first hinge hole (81).

9. The electromagnet according to claim 8, characterized in that, The elastic element (4) is configured as a spring, which is sleeved on the moving magnetic core (3) and the connector (34).

10. The electromagnet according to claim 9, characterized in that, The frame (1) has a first baffle (12) at its first end, and the connector (34) has a second baffle (341). The first end of the spring abuts against the first baffle (12), and the second end abuts against the second baffle (341).

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