Distance detection mechanism for drum brake

Abstract

A distance detection mechanism of a drum brake belongs to the technical field of tractor brake. The drum brake comprises an electromagnet part, a brake arm and a brake spring. The electromagnet part comprises a static core, a moving core, a coil assembly and a top rod. When braking, the brake spring pushes the brake arm to brake and at the same time pushes against the top rod to keep a gap between the static core and the moving core. When releasing, the coil assembly is electrified, the static core and the moving core attract each other, the moving core drives the top rod to move outward, and the brake further comprises a distance sensor and a sensed part. The distance sensor is installed on the static core and comprises a distance detection part and an output end. The distance detection part is oppositely arranged with the sensed part. The sensed part moves synchronously with the moving core. The distance detection part is used for detecting the distance B between the distance detection part and the sensed part. The output end transmits the collected distance B to a control system. Advantage: According to the reference value and the detection value, the working condition of the brake and the wear condition of the brake lining can be judged.

Description

Technical Field

[0001] This utility model belongs to the field of traction machine brake technology, specifically relating to a distance detection mechanism for a drum brake. Background Technology

[0002] Previously, drum brakes on elevator traction machines were equipped with mechanical microswitches to detect the braking and releasing actions of the drum brake. When the microswitch was activated by the moving iron core or brake arm of the drum brake, it would perform a corresponding action: the normally open contact would close, and the normally closed contact would open, or vice versa. This provided the control system with a signal that the brake was functioning normally. Otherwise, the control system would initiate corresponding procedures, such as alarms or emergency braking, affecting elevator safety. A mechanical microswitch typically consists of a spring-loaded contact and a movable contact. When the contact is subjected to external force, the movable contact displaces, changing the switch's state. Because microswitches are mechanical switches, mechanical fatigue can occur in the moving parts during frequent brake operation, potentially leading to errors over time. Therefore, frequent maintenance, adjustment, or replacement is necessary.

[0003] In view of the aforementioned existing technology, it is necessary to further improve the detection components of existing drum brakes. To this end, the applicant has made a beneficial design, and the technical solution described below arises from this context. Utility Model Content

[0004] The objective of this invention is to provide a distance detection mechanism for a drum brake, which can detect the distance between the distance detection unit and the sensed component through a distance sensor, collect and transmit the data to the control system, and the control system can determine the working condition of the brake and understand the wear of the brake pads based on preset reference values ​​and detection values, thereby improving the safety of the brake.

[0005] The present invention accomplishes its objective as follows: a distance detection mechanism for a drum brake, wherein the drum brake includes an electromagnet component, an adjusting bolt, a brake arm, a brake spring, and a brake pad mounted on the brake arm. The electromagnet component includes a stationary iron core, a moving iron core, a coil assembly, a cylindrical housing, and a push rod. Two sets of coil assemblies are arranged on the left and right sides of the inner wall of the cylindrical housing, and each set of coil assemblies has a corresponding moving iron core inside. The stationary iron core is tightly fixed to both ends of the cylindrical housing. The push rod, fixed to the moving iron core, extends beyond the cylindrical housing after passing through the stationary iron core and corresponds to the adjusting bolt. The adjusting bolt is fastened to the end of the brake arm, and the brake arm is pivotally mounted on the machine body via a fixing pin. During braking, the brake spring pushes the brake arm to engage the brake, while simultaneously pressing against the push rod to maintain a gap between the stationary and moving iron cores. During release, the coil assembly is energized, and the stationary and moving iron cores attract each other. The moving iron core drives the push rod to move outward. The drum brake also includes a distance sensor and a sensed component. A distance sensor is directly or indirectly mounted on the stationary iron core. The distance sensor includes a distance detection unit and an output terminal. The distance detection unit is positioned opposite the sensed component, and the sensed component moves synchronously with the moving iron core. The distance detection unit detects the distance B between itself and the sensed component, and the output terminal transmits the collected distance B to the control system.

[0006] In a specific embodiment of this utility model, the output terminal is electrically connected to the data acquisition component, and the data acquisition component is electrically connected to the control system.

[0007] In another specific embodiment of this utility model, the control system is electrically connected to the alarm device.

[0008] In another specific embodiment of this utility model, a distance sensor is indirectly installed on the stationary iron core. Specifically, the distance sensor is installed on a mounting component fixed on the stationary iron core.

[0009] In another specific embodiment of this utility model, the sensing element is a set of discs disposed at the end of the top rod.

[0010] In another specific embodiment of this utility model, the sensing element is directly mounted on the brake arm, and the sensing element sensed by the distance sensor is a bolt, which is mounted on the brake arm near the adjusting bolt.

[0011] In a further specific embodiment of this utility model, the sensed component is indirectly mounted on the brake arm, and the sensed component sensed by the distance sensor is mounted on one end of a mounting plate. The other end of the mounting plate is fixedly connected to the brake arm, so that the sensed component and the moving iron core can move synchronously. The mounting plate is adaptively bent according to the installation position of the distance sensor.

[0012] In a further specific embodiment of this utility model, the distance detection unit and the output end are installed in the housing, and the housing is directly or indirectly installed on the stationary iron core.

[0013] In another specific embodiment of this utility model, a gap A is left between the stationary iron core and the moving iron core. At this time, the distance sensor detects a distance B1 between itself and the sensed component. The distance B output by the output terminal is transmitted to the control system. When the control system calculates that B=B1-A, it indicates that the brake is in the open state.

[0014] In yet another specific embodiment of this utility model, the maximum allowable wear value of the brake pads is converted to a maximum distance A1 between the stationary iron core and the moving iron core. A1 is preset in the control system. When the drum brake is engaged, the distance sensor detects the distance B between itself and the sensed component. The distance sensor transmits the distance B to the data acquisition component, which in turn transmits the data B to the control system. The control system calculates and determines that when B is between B1 and B1+A1, it indicates that the brake is in a normal braking state and the brake pads are not worn. When the distance sensor detects that the distance B between the distance detection unit and the sensed component is greater than B1+A1, it indicates that the brake pads of the brake have been worn.

[0015] This utility model, due to the aforementioned structure, has the following beneficial effects: First, the distance sensor detects the distance between the detection unit and the sensed component and transmits this information to the control system in a timely manner. The control system then uses a preset reference value and the detected value to determine the working state of the brake, i.e., whether it is in the open or closed state. Second, the maximum gap value between the stationary iron core and the moving iron core when the brake is closed is preset to the control system. The control system determines whether the brake pads are worn based on the preset value and the detected value, thereby warning the user to replace the brake pads in time, improving the safety of the drum brake. A single distance sensor can simultaneously determine the working status of the brake and the wear condition of the brake pads, providing comprehensive functionality and a simple structure. Third, because the distance sensor does not contact the sensed component, it will not suffer from mechanical fatigue due to frequent contact, unlike mechanical microswitches, thus extending its service life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an embodiment of the drum brake of this utility model in the braking state; Figure 2 This is a schematic diagram of the assembly of the distance sensor and the sensed component described in this utility model; Figure 3 This is a structural block diagram of the distance detection mechanism described in this utility model; Figure 4 This is a diagram showing the braking state of the drum brake described in this utility model under brake pad wear conditions. Figure 5 This is a schematic diagram of another embodiment of the drum brake described in this utility model in the braking state; Figure 6 This is a schematic diagram of another embodiment of the drum brake described in this utility model in the braking state.

[0017] In the diagram: 1. Distance sensor, 11. Distance detection unit, 12. Output terminal, 13. Housing, 101. Sensing element, 1011. Mounting plate, 102. Mounting component; 2. Electromagnet component, 21. Stationary iron core, 22. Moving iron core, 23. Coil assembly, 24. Cylindrical housing, 25. Push rod, 26. Machine body fixing component; 3. Adjusting bolt; 4. First locking nut; 5. Brake arm; 6. Pull rod; 7. Brake spring, 71. Spring seat, 72. Second locking nut; 8. Brake pad; 9. Brake wheel; 10. Data acquisition component; 20. Control system; 30. Alarm device. Detailed Implementation

[0018] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. However, the description of the embodiments is not a limitation on the technical solution. Any formal but not substantive changes made based on the concept of this utility model should be considered within the protection scope of this utility model.

[0019] In the following description, all directional or orientational concepts involving up, down, left, right, front, and back are based on the positions shown in the corresponding figures, and therefore should not be construed as a special limitation on the technical solution provided by this utility model.

[0020] Please see Figures 1 to 3This utility model relates to a distance detection mechanism for a drum brake. The drum brake is symmetrically installed on both sides of the traction machine body, and a distance sensor 1 for detecting the brake's stroke is installed on it. The drum brake mainly includes the distance sensor 1, an electromagnet component 2, an adjusting bolt 3, a first locking nut 4, a brake arm 5, a pull rod 6, a brake spring 7, a brake pad 8, and a brake wheel 9. The electromagnet component 2 includes a stationary iron core 21, a moving iron core 22, a coil assembly 23, a cylindrical shell 24, a push rod 25, and a machine body fixing component 26. Two sets of coil assemblies 23 are provided on the left and right sides of the inner wall of the cylindrical shell 24. Each set of coil assemblies 23 has a corresponding moving iron core 22 inside. The two ends of the cylindrical shell 24 are fastened to the stationary iron core 21 by screws, and the stationary iron core 21 closes the openings at both ends of the cylindrical shell 24. The push rod 25, fixed on the moving iron core 22, extends to the outside of the cylindrical shell 24 after passing through the through hole in the middle of the stationary iron core 21, and corresponds to the adjusting bolt 3.

[0021] The brake arm 5 is pivotally mounted on the machine body via a fixing pin. The brake pad 8 is attached to the brake arm 5 and corresponds to the brake wheel 9. The pull rod 6 passes through the brake arm 5 and is connected to the machine body fixing component 26. The brake spring 7 is sleeved on the pull rod 6, with one end abutting against the spring seat 71 at the end of the pull rod 6 and the other end abutting against the corresponding positioning groove on the brake arm 5. A second locking nut 72 is screwed onto the pull rod 6 outside the spring seat 71. By screwing in and out of the second locking nut 72, the spring force of the brake spring 7 can be adjusted. This spring force pushes the brake arm 5, causing the brake pad 8 on the brake arm 5 to firmly press against the brake wheel 9, thereby stopping the brake wheel 9. The adjusting bolt 3 is installed at the upper end of the brake arm 5, and a first locking nut 4 is screwed onto it.

[0022] A distance sensor 1 is directly or indirectly mounted on the stationary iron core 21, and a sensing element 101 is directly or indirectly mounted on the push rod 25 or brake arm 5 connecting the moving iron core 22. In this embodiment, the distance sensor 1 is indirectly mounted on the stationary iron core 21. Specifically, the distance sensor 1 is mounted on the mounting member 102 fixed on the stationary iron core 21.

[0023] like Figure 2 , Figure 3As shown, the distance sensor 1 includes a distance detection unit 11, an output terminal 12, and a housing 13 for mounting the distance detection unit 11 and the output terminal 12. The distance detection unit 11 is disposed opposite to the sensed element 101. The housing 13 is directly or indirectly mounted on the stationary iron core 21. The sensed element 101 moves synchronously with the moving iron core 22. In this embodiment, the sensed element 101 is mounted on the push rod 25, and the sensed element 101 is a disc set at the end of the push rod 25. The distance detection unit 11 is used to detect the specific distance B between the distance detection unit 11 and the sensed element 101, thereby reflecting the specific distance between the stationary iron core 21 and the moving iron core 22. The detection method of the distance detection unit 11 is to convert the measured non-electrical physical quantity into a change in electrical physical quantity parameters, process the data, and transmit a signal. In this embodiment, the measured non-electrical physical quantity is distance, thereby realizing the detection of various gaps in the brake.

[0024] like Figure 2 , Figure 3 As shown, the output terminal 12 transmits the collected specific distance B to the control system. Specifically, the output terminal 12 is electrically connected to the data acquisition component 10, which in turn is electrically connected to the control system 20, which is in turn electrically connected to the alarm device 30. The control system 20 is a proprietary control system in the current elevator industry. The data acquisition component 10 is a processor that converts the data output by the distance sensor 1 into a data format that the control system 20 can receive and recognize. Existing data acquisition chips capable of this function can be applied to this embodiment. The data acquisition component 10 collects and converts the specific distance B between the distance detection unit 11 and the sensed element 101 detected by the distance sensor 1. The data acquisition component 10 then sends the converted specific distance B data to the control system 20, which analyzes and judges based on the received specific distance B.

[0025] Please continue reading. Figures 1 to 4 The working principle of the distance detection mechanism of the drum brake described in this embodiment is as follows: When the drum brake is debugged, the elevator traction machine is in a de-energized state. The brake spring 7 pushes the brake arm 5 towards the brake wheel 9, and the pair of brake pads 8 on its inner side engage the brake wheel 9. At the same time, the adjusting bolt 3 on the brake arm 5 abuts against the top rod 25, maintaining a gap between the stationary iron core 21 and the moving iron core 22. Figure 1 At this time, the distance sensor 1 detects a distance of B1 between itself and the sensed element 101.

[0026] When the brake is in the open state, the coil assembly 23 is energized, forming an electromagnetic circuit between the stationary iron core 21, the moving iron core 22, and the cylindrical shell 24, generating an electromagnetic force. This causes the stationary iron core 21 to attract the moving iron core 22, causing the moving iron core 22 to move towards the stationary iron core 21. The movement stroke of the moving iron core 22 is A. Simultaneously, under the action of the electromagnetic force, the electromagnetic force overcomes the spring force of the brake spring 7, and the push rod 25 pushes against the adjusting bolt 3, causing the brake pad 8 on the brake arm 5 to leave the surface of the brake wheel 9. The brake wheel 9 rotates freely. At this time, the distance sensor 1 detects the distance B between itself and the sensed element 101. The distance sensor 1 transmits the distance B to the data acquisition unit 10, which in turn transmits the data B to the control system 20. If the control system 20 determines that B = B1 - A, it indicates that the brake is in the open state. Here, the distance B1 and the movement stroke A of the moving iron core 22 are input into the control system 20 beforehand.

[0027] like Figure 4 As shown, assuming the brake pads 8 are worn, when the brake is in braking condition, the distance between the stationary iron core 21 and the moving iron core 22 will increase, and the distance between the distance detection unit 11 and the sensed element 101 will also increase. If the maximum permissible wear value of the brake pads 8 is 'a', during braking, the brake arm 5 will... Figure 4 Rotating in the direction of arrow b, the brake arm 5 is brought closer to the brake wheel 9, and the upper end of the brake arm 5 is brought closer to the electromagnet component 2. The adjusting bolt 3 at the upper end of the brake arm 5 further pushes the push rod 25, increasing the distance between the stationary iron core 21 and the moving iron core 22 by A1. Using existing known technology, the maximum allowable wear value a is converted into the increased distance A1 between the stationary iron core 21 and the moving iron core 22. At this time, the distance sensor 1 detects that the distance between itself and the sensed component 101 has increased from B1 to B1+A1, and A1 is preset into the control system 20. When the drum brake engages, distance sensor 1 detects the distance B between itself and the sensed component 101. Distance sensor 1 transmits distance B to data acquisition component 10, which in turn transmits data B to control system 20. Control system 20 determines that if B is between B1 and B1+A1, it indicates that the brake is in normal braking condition and the brake pads 8 are not worn. When distance sensor 1 detects that the distance B between distance detection unit 11 and sensed component 101 is greater than B1+A1, it indicates that the brake pads 8 are worn. Control system 20 will send a command to alarm device 30 to issue an alarm signal, requiring maintenance personnel to replace the brake pads 8 and readjust the drum brake.

[0028] like Figure 5 As shown, in another embodiment, the sensed element 101 sensed by the distance sensor 1 is directly mounted on the brake arm 5. Specifically, the sensed element 101 sensed by the distance sensor 1 is a bolt, which is mounted on the brake arm 5 near the adjusting bolt 3.

[0029] like Figure 6 As shown, in another embodiment, the sensed element 101 is indirectly mounted on the brake arm 5. Specifically, the sensed element 101 is mounted on one end of a mounting plate 1011 at the end of the brake arm 5, and the other end of the mounting plate 1011 is fixedly connected to the brake arm 5, thus realizing the indirect mounting of the sensed element 101 on the brake arm 5. In this embodiment, the mounting plate 1011 can be adapted to the installation position of the distance sensor 1 so that the sensed element 101 can be accurately sensed.

Claims

1. A distance detection mechanism for a drum brake, the drum brake comprising an electromagnet component (2), an adjusting bolt (3), a brake arm (5), a brake spring (7), and a brake pad (8) disposed on the brake arm (5). The electromagnet component (2) comprises a stationary iron core (21), a moving iron core (22), a coil assembly (23), a cylindrical housing (24), and a push rod (25). The inner wall of the cylindrical housing (24) is provided with two sets of coil assemblies (23) on the left and right sides. Each set of coil assemblies (23) is provided with a moving iron core (22) corresponding to the inside of each set of coil assemblies (23). The two ends of the cylindrical housing (24) are tightly fitted with the stationary iron core (21) and fixed to the moving iron core. The push rod (25) on the core (22) extends to the outside of the cylindrical shell (24) after passing through the stationary iron core (21) and corresponds to the adjusting bolt (3). The adjusting bolt (3) is fastened to the end of the brake arm (5). The brake arm (5) is pivotally placed on the machine body by a fixing pin. When braking, the brake spring (7) pushes the brake arm (5) to engage the brake and simultaneously presses against the push rod (25) to maintain a gap between the stationary iron core (21) and the moving iron core (22). When releasing, the coil assembly (23) is energized, and the stationary iron core (21) and the moving iron core (22) attract each other. The moving iron core (22) drives the push rod (25) to move outward. The feature is that: The drum brake also includes a distance sensor (1) and a sensed element (101). The distance sensor (1) is directly or indirectly installed on the stationary iron core (21). The distance sensor (1) includes a distance detection unit (11) and an output terminal (12). The distance detection unit (11) is arranged opposite to the sensed element (101). The sensed element (101) moves synchronously with the moving iron core (22). The distance detection unit (11) is used to detect the distance B between the distance detection unit (11) and the sensed element (101). The output terminal (12) transmits the collected distance B to the control system (20).

2. The distance detection mechanism for a drum brake according to claim 1, characterized in that: The output terminal (12) is electrically connected to the data acquisition component (10), and the data acquisition component (10) is electrically connected to the control system (20).

3. The distance detection mechanism for a drum brake according to claim 2, characterized in that: The control system (20) is electrically connected to the alarm device (30).

4. The distance detection mechanism for a drum brake according to claim 1, characterized in that: A distance sensor (1) is indirectly installed on the stationary iron core (21). Specifically, the distance sensor (1) is installed on a mounting component (102) fixed on the stationary iron core (21).

5. The distance detection mechanism for a drum brake according to claim 1, characterized in that: The sensing element (101) is a set of discs located at the end of the top rod (25).

6. The distance detection mechanism for a drum brake according to claim 1, characterized in that: The sensing element (101) is directly mounted on the brake arm (5). The sensing element (101) sensed by the distance sensor (1) is a bolt, which is mounted on the brake arm (5) near the adjusting bolt (3).

7. The distance detection mechanism for a drum brake according to claim 1, characterized in that: The sensing element (101) is indirectly mounted on the brake arm (5). The sensing element (101) sensed by the distance sensor (1) is mounted on one end of a mounting plate (1011). The other end of the mounting plate (1011) is fixedly connected to the brake arm (5) to realize synchronous movement between the sensing element (101) and the moving iron core (22). The mounting plate (1011) is adapted to the installation position of the distance sensor (1).

8. The distance detection mechanism for a drum brake according to claim 1, characterized in that: The distance detection unit (11) and the output end (12) are installed in the housing (13), which is directly or indirectly installed on the stationary iron core (21).

9. The distance detection mechanism for a drum brake according to claim 1, characterized in that: When the drum brake is applied, the coil assembly (23) is de-energized, and the distance between the distance sensor (1) and the sensed object (101) is B1. When the drum brake is released, the coil assembly (23) is energized, generating an electromagnetic force between the stationary iron core (21) and the moving iron core (22). The moving iron core (22) moves towards the stationary iron core (21), and the stroke of the moving iron core (22) is A. At this time, the distance sensor (1) detects the distance B between itself and the sensed object (101) and transmits the distance B to the data acquisition component (10). The data acquisition component (10) then transmits the data B to the control system (20). If the control system (20) determines that B = B1 - A, it indicates that the brake is in the open state.

10. The distance detection mechanism for a drum brake according to claim 9, characterized in that: The increased distance A1 between the stationary iron core (21) and the moving iron core (22) is calculated based on the maximum permissible wear value a of the brake pad (8). A1 is preset into the control system (20). When the drum brake is engaged, the distance sensor (1) detects the distance B between itself and the sensed component (101). The distance sensor (1) transmits the distance B to the data acquisition component (10). The data acquisition component (10) then transmits the data B to the control system (20). When the control system (20) determines that B is between B1 and B1+A1, it indicates that the brake is in normal braking condition and the brake pad (8) is not worn. When the distance sensor (1) detects that the distance B between the distance detection unit (11) and the sensed component (101) is greater than B1+A1, it indicates that the brake pad (8) of the brake has been worn.

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