Electric vehicle drum brake device based on magnetically controlled shape memory alloy drive

Abstract

The present invention belongs to the technical field of brakes, and specifically relates to an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy, comprising a brake drum and a controller, wherein the brake drum is provided with an articulated seat, the articulated seat is provided with a first brake shoe and a second brake shoe, the first brake shoe and the second brake shoe are both provided with friction plates, the brake drum is provided with a first mounting seat, the first mounting seat is provided with a first magnetically controlled shape memory alloy block, the brake drum is provided with a first coil seat, the first coil seat is provided with a first coil, the brake drum is provided with a mounting ring, the mounting ring is provided with a second mounting seat, the second mounting seat is provided with a second magnetically controlled shape memory alloy block, the brake drum is provided with a second coil seat, the second coil seat is provided with a second coil, and the first brake shoe and the second brake shoe are both provided with a reset spring; the friction plates of a single set of brake shoes are prevented from having an excessively high operating temperature for a long time, so that the braking performance of the drum brake is weakened, and in the event of an emergency brake, the friction plates of the two sets of brake shoes can brake the brake drum at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of brakes, and in particular relates to an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy. Background Art

[0002] The drum brake device uses the friction between the stationary brake pads in the brake drum and the inner surface of the friction drum that rotates with the rotation of the wheel to generate corresponding friction force to reduce the rotation speed of the wheel, thereby achieving the braking purpose. Due to its good self-braking effect and large braking force, it is widely used in the rear wheel braking of small cars and the braking of large cars.

[0003] The purpose of the present invention is to solve the problem that there is currently no simple and easy-to-control drum brake. In view of the fact that the driving force source of current drum brakes is complex and the control precision is low, a drum brake is designed that can achieve the braking purpose by controlling the current size; the complex oil circuit system and air circuit system are simplified into an integrated circuit system, so that the control precision of the driving force is guaranteed and the whole brake system is simplified; and because the drum brake adopts a sealed structure, the large amount of heat energy generated by the brake pads and the friction drum cannot be quickly dissipated when the drum brake is under long-term high load or continuous braking, resulting in the temperature of the brake pads and the friction drum rising, and the friction coefficient is reduced due to the high temperature, which ultimately leads to the weakening of the braking performance of the drum brake, thermal decay, and even a major safety accident of brake failure. Summary of the invention

[0004] The purpose of the present invention is to provide an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy, which utilizes the friction plates on two sets of brake shoes to work alternately during braking, thereby preventing the friction plates of a single set of brake shoes from working at too high a temperature for a long time, which leads to a reduction in the friction coefficient, thereby causing the braking performance of the drum brake to weaken and causing thermal decay problems. In addition, in the event of emergency braking, the friction plates of the two sets of brake shoes can brake the brake drum at the same time, increasing the contact area between the friction plates and the brake drum, so that the braking effect will be optimal.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] An electric vehicle drum brake device driven by a magnetically controlled shape memory alloy comprises a brake drum and a controller, wherein the controller is electrically connected to a vehicle power supply, the controller is connected to a brake pedal signal, an articulated seat is provided at the bottom of the brake drum, and a brake mechanism is articulated on both sides of the articulated seat, the brake mechanism comprises a first brake shoe and a second brake shoe, the first brake shoe is located above the second brake shoe, the first brake shoe and the second brake shoe are both fixedly connected with a friction plate, the brake drum is fixedly connected with a first mounting seat, and first magnetically controlled shape memory alloy blocks are assembled on both sides of the first mounting seat, the two first magnetically controlled shape memory alloy blocks are respectively connected to the upper side of the corresponding first brake shoe, and the brake drum is fixedly connected with a first magnetically controlled shape memory alloy block located on the two first magnetically controlled shape memory alloy blocks There are two first coil seats on the side, and the two first coil seats are both equipped with a first coil. A mounting ring is provided in the middle of the brake drum, and second mounting seats are fixedly connected on both sides of the mounting ring. The two second mounting seats are both equipped with second magnetically controlled shape memory alloy blocks, and the two second magnetically controlled shape memory alloy blocks are respectively connected to the upper sides of the corresponding second brake shoes. The brake drum is fixedly connected with two second coil seats located on the lower sides of the two second magnetically controlled shape memory alloy blocks, and the two second coil seats are both equipped with second coils, and the resistance of the second coil is equal to the resistance of the first coil. Reset springs are provided on the upper sides between the two first brake shoes and between the two second brake shoes, and the two first coils and the two second coils are electrically connected to the controller.

[0007] By adopting the technical solution of the present invention, when the user steps on the brake pedal, the controller connects the power supply of the vehicle to the two first coils, the two first coils are energized to generate a magnetic field, the magnetic field acts on the two first magnetically controlled shape memory alloys, the two first magnetically controlled shape memory alloys are deformed under the action of the magnetic field, so that the two first magnetically controlled shape memory alloys will overcome the elastic force of the return spring and push the first brake shoes on both sides closer to the inner side of the brake drum, so that the friction plate on the first brake shoe contacts the inner side of the brake drum to brake the vehicle; when the user continues to step on the brake pedal downward, the height of the brake pedal gradually decreases, and the controller receives the height position of the brake pedal. The setting signal will control the current size of the automobile power supply flowing into the two first coils, so that the current of the two first coils gradually increases. In this way, the larger the current obtained by the two first coils, the larger the magnetic field will be. Therefore, when the magnetic field becomes larger, the force of the two first magnetically controlled shape memory alloys will be stronger, and the elongation of the two first magnetically controlled shape memory alloys will become larger, so that the friction plate on the first brake shoe gradually approaches the inner side of the brake drum, thereby increasing the braking force of the first brake shoe on the brake drum, and the braking effect on the car is more obvious; when the user releases the brake pedal, the brake pedal will automatically return to its original position, and the brake pedal will gradually rise during the resetting process. The controller obtains the position height of the brake pedal and controls the current of the two first coils from the vehicle power supply to gradually reduce it. Under the reset elastic force of the reset spring, the elongation of the two first magnetically controlled shape memory alloys will gradually decrease, and the friction plate on the first brake shoe will gradually move away from the inner side of the brake drum. When the brake pedal is fully reset, the controller will completely shut down the current flowing into the two first coils from the vehicle power supply. The reset elastic force of the reset spring will restore the two first magnetically controlled shape memory alloys to their initial state, so that the friction plates on the two first brake shoes will no longer be in contact with the inner side of the brake drum, and the vehicle will no longer be braked, and during braking, the vehicle will no longer be braked. After the pedal is completely reset, the controller will receive the position height from the brake pedal, and at this time the controller will control the vehicle power supply to be connected to the two second coils, so that the vehicle power supply is disconnected from the two first coils; when the brake operator steps on the brake pedal again, the controller receives the position height signal of the brake pedal, and flows the current of the vehicle power supply into the two second coils, and the two second coils generate a magnetic field, which acts on the corresponding second magnetically controlled shape memory alloy blocks. The two second magnetically controlled shape memory alloy blocks extend under the action of the magnetic field, and will push the second brake shoe close to the inner side of the brake drum, and the friction plate on the second brake shoe will contact the brake drum to brake the car;Therefore, every time the operator releases the brake pedal once and then steps on the brake pedal again to brake the car, another set of brake shoes will be used to brake the car. In this way, the friction pads on the two sets of brake shoes work alternately during braking, which can prevent the friction pads of a single set of brake shoes from working for a long time due to excessively high temperatures, resulting in a decrease in the friction coefficient, which in turn leads to a weakening of the braking performance of the drum brake and the problem of thermal decay, thereby effectively improving the safety of the car during driving;

[0008] Reference Figure 4When the user brakes suddenly, the brake pedal is stepped on to a lower position to obtain a larger braking force. When the height of the brake pedal is at point X, if the car power supply is connected to the two first coils, the current flowing into the two first coils is K amperes; continue to step on the brake pedal, the controller receives the height signal of the brake pedal, and the controller will connect the two second coils to the car power supply, and the current output by the car power supply will become twice the original, that is, 2K amperes. Since the resistance of the second coil is equal to the resistance of the first coil, when the two second coils are also connected to the car power supply, the two second coils and the two first coils will be shunted, and the current flowing into the two first coils at this time depends on The current flowing into the two second coils is K amperes, and the current flowing into the two second coils is also K amperes, so that the two second coils obtain the same current as the two first coils, and the two second coils generate a magnetic field to act on the second magnetically controlled shape memory alloy block, so that the second magnetically controlled shape memory alloy block is stretched, and the length of the stretching of the second magnetically controlled shape memory alloy block is the same as the length of the stretching of the first magnetically controlled shape memory alloy block, so that the second magnetically controlled shape memory alloy block moves the second brake shoe to the same position as the first brake shoe. When the second brake shoe is close to the brake drum, the friction plate on the second brake drum will decelerate the brake drum, and when the first brake drum and the second brake drum are at the same displacement position, the first brake drum and the second brake drum can be used. The friction plate on the drum brakes the brake drum at the same time; continue to step on the brake pedal, the current output by the car power supply to the first coil and the second coil will continue to increase, thereby driving the first magnetically controlled shape memory alloy block and the second magnetically controlled shape memory alloy block to continue to extend, so that the friction plates on the first brake drum and the second brake drum are simultaneously close to the inner side of the brake drum, so that the brake drum obtains the maximum friction force and completely brakes the car; when the brake pedal is released to point X, the controller will control the current output by the car power supply to half of the original, that is, the current size is K amperes, and the controller disconnects the two second coils from the car power supply. The two second coils will no longer generate a magnetic field without current, and the two second magnetically controlled shape memory alloys The block will return to its initial state, and the first magnetically controlled shape memory alloy remains unchanged; in this way, when the car is braked suddenly, the brake pedal will pass through point X, so that the controller controls the car power supply to output a current twice as large as the original one, and controls the car power supply and another set of coils to be energized, so that the other set of coils obtains the same current as the original coils, then the friction plates of the two sets of brake shoes can brake the brake drum at the same time, increasing the contact area between the friction plates and the brake drum. In the case of emergency braking, the braking effect will be optimal, avoiding the braking effect in the emergency braking process being affected by setting two sets of brake shoes to work alternately and reducing the contact area between the friction plates and the brake drum, thereby further improving the safety of the car during driving.

[0009] It is further defined that the two first coils and the two second coils are connected in parallel, the two first coils are connected in series, and the two second coils are connected in series. Such a structure can conveniently control the current between the two first coils, the two second coils and the car power supply through the controller.

[0010] It is further defined that a first elastic gasket is provided between the first magnetically controlled shape memory alloy block and the first brake shoe, and a second elastic gasket is provided between the second magnetically controlled shape memory alloy block and the second brake shoe. Such a structure reduces the vibration force from the brake shoe to the first magnetically controlled shape memory alloy block and the second magnetically controlled shape memory alloy block.

[0011] It is further defined that an auxiliary spring is provided on the lower side between the two first brake shoes and the lower side between the two second brake shoes. Such a structure can assist the first brake shoe and the second brake shoe in resetting.

[0012] It is further defined that the first mounting seat, the second mounting seat and the brake drum are fixed by welding. Such a structure makes the first mounting seat and the second mounting seat more stable.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The complex oil circuit system and gas circuit system are simplified into an integrated circuit system, which ensures the control accuracy of the driving force and simplifies the entire braking system.

[0015] 2. Whenever the operator releases the brake pedal once and then steps on it again to brake the car, another set of brake shoes will be used to brake the car. In this way, the friction pads on the two sets of brake shoes will work alternately during braking, which can prevent the friction pads of a single set of brake shoes from working at too high a temperature for a long time, which will cause the friction coefficient to decrease, thereby weakening the braking performance of the drum brake and causing thermal decay problems, effectively improving the safety of the car during driving.

[0016] 3. When the car is braked suddenly, the brake pedal will pass through point X, so that the controller controls the car power supply to output twice the original current, and controls the car power supply and another set of coils to be energized, so that the other set of coils obtains the same current as the original coils. Then, the friction plates of the two sets of brake shoes can brake the brake drum at the same time, increasing the contact area between the friction plates and the brake drum. In the case of emergency braking, the braking effect will be optimal, avoiding the effect of the braking effect in the emergency braking process due to the alternating operation of the two sets of brake shoes, which reduces the contact area between the friction plates and the brake drum, and further improves the safety of the car during driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention can be further illustrated by means of non-limiting examples given in the accompanying drawings;

[0018] Figure 1 This is a schematic structural diagram of an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy according to an embodiment of the present invention;

[0019] Figure 2 It is a schematic cross-sectional structure diagram of an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy according to an embodiment of the present invention;

[0020] Figure 3 This is a control system diagram of an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy according to an embodiment of the present invention;

[0021] Figure 4 This is a current variation diagram of an electric vehicle drum brake device driven by a magnetically controlled shape memory alloy according to an embodiment of the present invention;

[0022] The main component symbols are described as follows:

[0023] Brake drum 1, articulated seat 11, first brake shoe 12, second brake shoe 13, friction plate 14, first mounting seat 2, first magnetically controlled shape memory alloy block 21, first coil seat 22, first coil 23, mounting ring 3, second mounting seat 31, second magnetically controlled shape memory alloy block 32, second coil seat 33, second coil 34, return spring 4, auxiliary spring 5. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1-4As shown, the electric vehicle drum brake device based on magnetically controlled shape memory alloy drive of the present invention includes a brake drum 1 and a controller, the controller is electrically connected to the vehicle power supply, and the controller is connected to the brake pedal signal, and is characterized in that: an articulated seat 11 is provided at the bottom of the brake drum 1, and a brake mechanism is articulated on both sides of the articulated seat 11, and the brake mechanism includes a first brake shoe 12 and a second brake shoe 13, the first brake shoe 12 is located above the second brake shoe 13, and the first brake shoe 12 and the second brake shoe 13 are fixedly connected with a friction plate 14, the brake drum 1 is fixedly connected with a first mounting seat 2, and the first mounting seat 2 is equipped with a first magnetically controlled shape memory alloy block 21 on both sides, and the two first magnetically controlled shape memory alloy blocks 21 are respectively connected to the upper side of the corresponding first brake shoe 12, and the brake drum 1 is fixedly connected with the first magnetically controlled shape memory alloy blocks 21 located at the two first brake shoes 12. There are two first coil seats 22 above the block 21, and the two first coil seats 22 are both equipped with a first coil 23. A mounting ring 3 is provided in the middle of the brake drum 1, and second mounting seats 31 are fixedly connected on both sides of the mounting ring 3. The two second mounting seats 31 are both equipped with second magnetically controlled shape memory alloy blocks 32. The two second magnetically controlled shape memory alloy blocks 32 are respectively connected to the upper sides of the corresponding second brake shoes 13. The brake drum 1 is fixedly connected with two second coil seats 33 located at the lower sides of the two second magnetically controlled shape memory alloy blocks 32. The two second coil seats 33 are both equipped with second coils 34, and the resistance of the second coil 34 is equal to the resistance of the first coil 23. A reset spring 4 is provided on the upper side between the two first brake shoes 12 and the upper side between the two second brake shoes 13. The two first coils 23 and the two second coils 34 are both electrically connected to the controller.

[0026] By adopting the technical solution of the present invention, when the user steps on the brake pedal, the controller connects the power supply of the vehicle to the two first coils 23, and the two first coils 23 are energized to generate a magnetic field. The magnetic field acts on the two first magnetically controlled shape memory alloys 21, and the two first magnetically controlled shape memory alloys 21 are deformed under the action of the magnetic field, so that the two first magnetically controlled shape memory alloys 21 overcome the elastic force of the return spring 4 and push the first brake shoes 12 on both sides closer to the inner side of the brake drum 1, so that the friction plate 14 on the first brake shoe 12 contacts the inner side of the brake drum 1 to brake the vehicle; when the user continues to step on the brake pedal downward, the height of the brake pedal gradually decreases, and the controller receives the height position of the brake pedal. The setting signal will control the current size of the automobile power supply flowing into the two first coils 23, so that the current of the two first coils 23 gradually increases. In this way, the larger the current obtained by the two first coils 23, the larger the magnetic field generated will be. Therefore, when the magnetic field of the two first magnetically controlled shape memory alloys 21 becomes larger, the force is stronger, and the elongation of the two first magnetically controlled shape memory alloys 21 will become larger, so that the friction plate 14 on the first brake shoe 12 gradually approaches the inner side of the brake drum 1, thereby increasing the braking force of the first brake shoe 12 on the brake drum 1, and the effect of braking the car is more obvious; when the user releases the brake pedal, the brake pedal will automatically return to its original position, and the brake pedal will gradually rise during the resetting process. The controller obtains the position height of the brake pedal, and controls the current of the two first coils 23 supplied by the vehicle power supply to gradually reduce it. Under the reset elastic force of the reset spring 4, the elongation of the two first magnetically controlled shape memory alloys 21 will gradually decrease, and the friction plate 14 on the first brake shoe 12 will gradually move away from the inner side of the brake drum 1. When the brake pedal is fully reset, the controller will completely shut down the current flowing into the two first coils 23 supplied by the vehicle power supply, and the reset elastic force of the reset spring 4 will restore the two first magnetically controlled shape memory alloys 21 to their initial state, so that the friction plates 14 on the two first brake shoes 12 will no longer be in contact with the inner side of the brake drum 1, and the vehicle will no longer be braked, and when the brake pedal is fully reset, the controller will completely shut down the current flowing into the two first coils 23 supplied by the vehicle power supply, and the reset elastic force of the reset spring 4 will restore the two first magnetically controlled shape memory alloys 21 to their initial state, so that the friction plates 14 on the two first brake shoes 12 will no longer be in contact with the inner side of the brake drum 1, and the vehicle will no longer be braked. After the plate is completely reset, the controller will receive the position height from the brake pedal, and at this time the controller will control the vehicle power supply to be connected to the two second coils 34, so that the vehicle power supply is disconnected from the two first coils 23; when the brake personnel steps on the brake pedal again, the controller receives the position height signal of the brake pedal, and flows the current of the vehicle power supply into the two second coils 34, and the two second coils 34 generate a magnetic field, which acts on the corresponding second magnetically controlled shape memory alloy blocks 32. The two second magnetically controlled shape memory alloy blocks 32 extend under the action of the magnetic field, and will push the second brake shoe 13 close to the inner side of the brake drum 1, and the friction plate 14 on the second brake shoe 13 will contact the brake drum 1, so as to brake the vehicle;Therefore, every time the operator releases the brake pedal once and then steps on the brake pedal again to brake the car, another set of brake shoes will be used to brake the car. In this way, the friction pads on the two sets of brake shoes work alternately during braking, which can prevent the friction pads of a single set of brake shoes from working for a long time due to excessively high temperatures, resulting in a decrease in the friction coefficient, which in turn leads to a weakening of the braking performance of the drum brake and the problem of thermal decay, thereby effectively improving the safety of the car during driving;

[0027] Reference Figure 4When the user brakes suddenly, the brake pedal is stepped on to a lower position to obtain a larger braking force. When the height of the brake pedal is at point X, if the car power supply is connected to the two first coils 23, the current flowing into the two first coils 23 is K amperes. The brake pedal is continued to be stepped on. The controller receives the height signal of the brake pedal and connects the two second coils 34 to the car power supply. The current output by the car power supply will become twice the original, that is, 2K amperes. Since the resistance of the second coil 34 is equal to the resistance of the first coil 23, when the two second coils 34 are also When connected to the car power supply, the two second coils 34 and the two first coils 23 will be shunted. At this time, the current flowing into the two first coils 23 is still K amperes, and the current flowing into the two second coils 34 is also K amperes. In this way, the two second coils 34 obtain the same current as the two first coils 23. The two second coils 34 generate a magnetic field to act on the second magnetically controlled shape memory alloy block 32, so that the second magnetically controlled shape memory alloy block 32 is stretched. The length of the second magnetically controlled shape memory alloy block 32 is the same as the length of the first magnetically controlled shape memory alloy 21, so that the second magnetically controlled shape memory alloy block 32 is stretched. The block 32 moves the second brake shoe 13 to the same position as the first brake shoe 12. When the second brake shoe 13 is close to the brake drum 1, the friction plate 14 on the second brake drum 13 will decelerate the brake drum 1, and when the first brake drum 12 and the second brake drum 13 are at the same displacement position, the friction plates 14 on the first brake drum 12 and the second brake drum 13 can be used to brake the brake drum 1 at the same time; continue to step on the brake pedal downward, the current output by the car power supply to the first coil 23 and the second coil 34 will continue to increase, thereby driving the first magnetically controlled shape memory alloy block 21 and the second magnetically controlled shape memory alloy block 22 to move the second brake shoe 13 to the same position as the first brake shoe 12. The controller controls the shape memory alloy block 32 to continue to extend, so that the friction plates 14 on the first brake drum 12 and the second brake drum 13 simultaneously approach the inner side of the brake drum 1, so that the brake drum 1 obtains the maximum friction force and completely brakes the car; when the brake pedal is released to point X, the controller controls the current output by the car power supply to be half of the original, that is, the current size is K amperes, and the controller disconnects the two second coils 34 from the car power supply. The two second coils 34 will no longer generate a magnetic field without current, and the two second magnetically controlled shape memory alloy blocks 32 will return to the initial state, and the first magnetically controlled shape memory alloy 21 remains unchanged;In this way, when the car is braked suddenly, the brake pedal 13 will pass through point X, so that the controller controls the car power supply to output a current twice as large as the original one, and controls the car power supply to energize another set of coils so that the other set of coils obtains a current as large as the original coils. Then, the friction plates of the two sets of brake shoes can brake the brake drum 1 at the same time, increasing the contact area between the friction plate 14 and the brake drum 1. In the case of emergency braking, the braking effect will be optimal, avoiding the braking effect in the emergency braking process being affected by reducing the contact area between the friction plate 14 and the brake drum 1 due to setting two sets of brake shoes to work alternately, thereby further improving the safety of the car during driving.

[0028] The present invention utilizes the friction plates on two groups of brake shoes to work alternately during braking, which can prevent the friction plates of a single group of brake shoes from having a reduced friction coefficient due to excessively high working temperature for a long time during operation, thereby causing the braking performance of the drum brake to weaken and causing the problem of thermal decay. In addition, in the event of emergency braking, the friction plates of the two groups of brake shoes can brake the brake drum 1 at the same time, thereby increasing the contact area between the friction plates 14 and the brake drum 1, so that the braking effect will be optimal.

[0029] Preferably, the two first coils 23 and the two second coils 34 are connected in parallel, the two first coils 23 are connected in series, and the two second coils 34 are connected in series. Such a structure can conveniently control the current between the two first coils 23, the two second coils 34 and the vehicle power supply through the controller.

[0030] Preferably, a first elastic gasket is provided between the first magnetically controlled shape memory alloy block 21 and the first brake shoe 12, and a second elastic gasket is provided between the second magnetically controlled shape memory alloy block 32 and the second brake shoe 13. Such a structure reduces the vibration force from the brake shoe 1 to the first magnetically controlled shape memory alloy block 21 and the second magnetically controlled shape memory alloy block 32. In fact, other structures can also be considered according to specific circumstances to reduce the vibration force from the brake shoe 1 to the first magnetically controlled shape memory alloy block 21 and the second magnetically controlled shape memory alloy block 32.

[0031] Preferably, an auxiliary spring 5 is provided on the lower side between the two first brake shoes 12 and the lower side between the two second brake shoes 13. Such a structure can assist the first brake shoe 12 and the second brake shoe 13 in resetting. In fact, other structures can also be considered according to specific circumstances to assist the first brake shoe 12 and the second brake shoe 13 in resetting.

[0032] Preferably, the first mounting seat 2, the second mounting seat 31 and the brake drum 1 are welded and fixed. Such a structure makes the first mounting seat 2 and the second mounting seat 31 more stable. In fact, other structures can also be considered according to specific circumstances to make the first mounting seat 2 and the second mounting seat 31 more stable.

[0033] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An electric vehicle drum brake device based on magnetically controlled shape memory alloy drive, comprising a brake drum (1) and a controller, wherein the controller is electrically connected to a vehicle power supply, and the controller is connected to a brake pedal signal, and is characterized in that: The brake drum (1) is provided with an articulated seat (11) at the bottom, and a brake mechanism is articulated on both the left and right sides of the articulated seat (11), and the brake mechanism comprises a first brake shoe (12) and a second brake shoe (13), and the first brake shoe (12) is located above the second brake shoe (13), and the first brake shoe (12) and the second brake shoe (13) are both fixedly connected with a friction plate (14), and the brake drum (1) is fixedly connected with a first mounting seat (2), and the first mounting seat (2) is equipped with a first magnetically controlled shape memory alloy block (21) on both the left and right sides, and the two first magnetically controlled shape memory alloy blocks (21) are respectively connected to the upper side of the corresponding first brake shoe (12), and the brake drum (1) is fixedly connected with two first coil seats (22) located above the two first magnetically controlled shape memory alloy blocks (21), and the two first coil seats (22) are both equipped with a first coil (23), and the A mounting ring (3) is provided in the middle of the brake drum (1), and second mounting seats (31) are fixedly connected on both sides of the mounting ring (3), and two second mounting seats (31) are equipped with second magnetically controlled shape memory alloy blocks (32), and the two second magnetically controlled shape memory alloy blocks (32) are respectively connected to the upper side of the corresponding second brake shoes (13). The brake drum (1) is fixedly connected with two second coil seats (33) located at the lower sides of the two second magnetically controlled shape memory alloy blocks (32), and the two second coil seats (33) are equipped with second coils (34), and the resistance of the second coil (34) is equal to the resistance of the first coil (23). Reset springs (4) are provided on the upper side between the two first brake shoes (12) and the upper side between the two second brake shoes (13), and the two first coils (23) and the two second coils (34) are electrically connected to the controller.

2. The electric vehicle drum brake device based on magnetically controlled shape memory alloy drive according to claim 1 is characterized in that: The two first coils (23) and the two second coils (34) are connected in parallel, the two first coils (23) are connected in series, and the two second coils (34) are connected in series.

3. The electric vehicle drum brake device based on magnetically controlled shape memory alloy drive according to claim 1 is characterized in that: A first elastic gasket is provided between the first magnetically controlled shape memory alloy block (21) and the first brake shoe (12), and a second elastic gasket is provided between the second magnetically controlled shape memory alloy block (32) and the second brake shoe (13).

4. The electric vehicle drum brake device based on magnetically controlled shape memory alloy drive according to claim 1 is characterized in that: An auxiliary spring (5) is provided on the lower side between the two first brake shoes (12) and on the lower side between the two second brake shoes (13).

5. The electric vehicle drum brake device based on magnetically controlled shape memory alloy drive according to claim 1 is characterized in that: The first mounting seat (2), the second mounting seat (31) and the brake drum (1) are fixed by welding.

Images