Anti-eccentric-wear device for brake shoe of locomotive brake

Abstract

The anti-eccentric-wear device for the locomotive brake shoe comprises a brake shoe bracket and a brake shoe body installed on the right side of the brake shoe bracket through a guide mechanism, and the end, away from the brake shoe bracket, of an elastic adjusting mechanism is attached to the left side face of the brake shoe body. Automatic gap adjusting mechanisms used for adjusting the position of the brake shoe body are symmetrically installed on the front side face and the rear side face of the upper end and the lower end of the brake shoe bracket. According to the anti-eccentric-wear device for the locomotive brake shoe, guide blocks in the guide mechanisms slide in guide grooves, eccentric wear caused by deviation is avoided, it is guaranteed that the brake shoe body can accurately make contact with a wheel tread in the later period, and the brake shoe body can be adjusted through multiple sets of elastic adjusting mechanisms installed between the brake shoe bracket and the brake shoe body; therefore, each position of the brake shoe body can be stressed more uniformly, the abrasion of each part of the brake shoe body is relatively balanced, the whole friction surface of the brake shoe body can be fully utilized, the braking efficiency is improved, and the service life of the brake shoe is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of brake shoe anti-eccentric wear, in particular to an anti-eccentric wear device for brake shoes of a locomotive brake machine. Background Art

[0002] The brake shoe of a locomotive brake is a key component that uses friction to slow down or stop the locomotive. However, due to various factors, such as brake shoe installation errors, uneven wheel treads, uneven brake cylinder force, etc., the brake shoe may be severely worn locally and eccentric wear may occur. Eccentric wear will reduce the effective friction area of ​​the brake shoe, reduce braking efficiency, and affect the braking performance and driving safety of the locomotive. At the same time, it will also shorten the service life of the brake shoe and increase operating costs. Therefore, an anti-eccentric wear device is needed to protect the brake shoe. For example, the patent title disclosed in the prior art with the announcement number "CN204956514U" is "A brake shoe support device capable of preventing brake shoe eccentric wear". It discloses that in order to enable the brake shoe support to maintain the deflection angle after automatically adjusting the deflection angle to prevent the brake shoe from eccentrically wearing up and down, a friction bracket, a friction block, a spring, a spring, a slider and a slider are provided, an inner hole is opened on the head of the screw rod, the friction bracket and the friction block can be placed inside the inner hole, the arc surface of the friction bracket with the protruding structure and the arc surface of the friction block are kept in a compressed state under the action of the spring, and the spring presses the slider on the friction bracket in the vertical direction. The spring presses the slider against the cover in the horizontal direction. The cover is connected to the brake shoe support by bolts. The spring and one end of the spring are fixed on the protruding cylinder of the friction block, and the other end is fixed on the slider or the protruding cylinder of the slider. When the brake shoe support has a certain deflection, the cover drives the spring and the friction bracket to deflect. There are fine teeth on the inner and outer arc surfaces. When the braking action is applied, the force that deflects the brake shoe support is the braking force, which is large. After the braking action is applied, the force that restores the brake shoe support is small. Therefore, due to the existence of the fine teeth, the deflection angle of the brake shoe support is locked. The existence of the spring and the spring makes the brake shoe support The brake shoe support can absorb the vibration of the locomotive vehicle while adapting to the movement of the wheel, preventing the deflection angle of the brake shoe support from changing due to vibration when the braking effect is cancelled. For example, the patent name disclosed in the prior art with the announcement number "CN106347408A" is "A device for preventing brake shoe eccentric wear of a basic braking device", which discloses that a stop plate is welded to the lower end of the bogie, the stop plate is fixedly connected to the stop block, the stop plate is placed on the outside of the basic brake seat of the bogie, the stop plate is fixedly connected to the stop block by bolts, an adjustment gasket is provided between the stop plate and the stop block, and an adjustment gasket is provided on the base of the bogie. A stop plate is welded to the outer side of the basic brake seat, and the stop block and the adjusting gasket are bolted to the inner side of the stop plate. Since the stop plate is welded to the bogie frame, it can effectively prevent the brake shoe of the basic brake device from wearing eccentrically to the outside. You only need to adjust the adjusting gasket between the inner side of the stop plate and the stop block to adjust the installation size of the basic brake device. After the locomotive returns to the section, you only need to check whether the stop block is worn, which effectively liberates labor. This anti-eccentric wear device effectively solves the problem of eccentric wear of the brake shoe of the basic brake device, and brings great convenience to assembly, effectively liberates labor and saves maintenance costs.

[0003] When in use, the anti-eccentric wear device in the above-mentioned prior art prevents the brake shoe of the basic braking device from wearing eccentrically to the outside by welding the stop plate to the bogie frame. However, due to the relatively simple structure, the entire anti-eccentric wear device cannot be guided and elastically adjusted. When the brake shoe encounters a large pressure locally, the brake shoe will still be subjected to uneven force as a whole, resulting in local eccentric wear. Therefore, we propose an anti-eccentric wear device for the brake shoe of a locomotive brake machine to solve the above-mentioned problems. Summary of the invention

[0004] The object of the present invention is to provide an anti-eccentric wear device for locomotive brake shoes, so as to solve the problem raised in the above background technology that the anti-eccentric wear devices currently on the market are relatively simple in structure, so that the entire anti-eccentric wear device cannot be guided and elastically adjusted. When the brake shoe encounters a large pressure locally, the brake shoe will still be subjected to uneven force as a whole, resulting in local eccentric wear.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an anti-eccentric wear device for brake shoes of a locomotive brake machine, comprising a brake shoe bracket, and a brake shoe body installed on the right side of the brake shoe bracket through a guide mechanism, elastic adjustment mechanisms are installed on the right sides of the upper and lower ends of the brake shoe bracket, and one end of the elastic adjustment mechanism away from the brake shoe bracket is arranged to fit the left side of the brake shoe body, and automatic gap adjustment mechanisms for adjusting the position of the brake shoe body are symmetrically installed on the front and rear side surfaces of the upper and lower ends of the brake shoe bracket.

[0006] Preferably, the middle portion of the brake shoe bracket is arranged in a "U" shape, the upper and lower ends of the brake shoe bracket are arranged in an arc shape, and the guide mechanism includes guide grooves symmetrically opened in the middle portion of the brake shoe bracket.

[0007] Through the arrangement of the above structure, it is convenient to install the guide mechanism inside the middle part of the brake shoe bracket for good guiding use.

[0008] Preferably, a connecting block is installed on the left side of the brake shoe body, and guide blocks are symmetrically installed on the upper and lower sides of the connecting block. The outer side of the guide block is slidably connected to the guide groove, and the left side of the connecting block is connected to the inside of the brake shoe bracket through a connecting spring.

[0009] Through the arrangement of the above structure, the stored force of the connecting spring will drive the brake shoe body to reset, so as to facilitate the next use of the brake shoe body.

[0010] Preferably, the elastic adjustment mechanism includes a connecting sleeve connected to the brake shoe bracket, and also includes an adjustment column slidingly connected in the connecting sleeve through a return spring, and a ball is installed on the outer end of the adjustment column, and the ball is in close contact with the left side surface of the brake shoe body.

[0011] Through the setting of the above structure, one end of the adjusting column can slide in the connecting sleeve. At the same time, through the setting of the ball, the contact area between the ball and the brake shoe body can be reduced, which is convenient for reducing the friction generated between the brake shoe body and the ball in the later stage.

[0012] Preferably, the automatic gap adjustment mechanism includes a rotating rod installed on the front and rear sides of the upper and lower ends of the brake shoe bracket, an arc-shaped self-push plate is fixed through the outer side of the rotating rod, a vortex spring is nested and connected to the outer side of the end of the rotating rod close to the brake shoe bracket, the other end of the vortex spring is connected to the brake shoe bracket, and a first rolling column is rotatably installed inside the end of the self-push plate away from the rotating rod, and the first rolling column is in close contact with the left side of the brake shoe body.

[0013] By setting the above structure, the contact area between the first rolling column and the brake shoe body can be reduced, thereby reducing the friction force generated when the first rolling column pushes the brake shoe body.

[0014] Preferably, the brake shoe body forms a sliding structure through a self-pushing plate.

[0015] Through the arrangement of the above structure, the self-pushing plate can exert a thrust on the brake shoe body, so that the brake shoe body can move well and fit in contact with the wheel tread.

[0016] Preferably, the upper and lower side surfaces of the middle region of the brake shoe bracket are grooved with threaded rods installed therein, an adjusting frame is threadedly connected to the outer side of the threaded rod, and the upper end of the adjusting frame is connected to a second rolling column.

[0017] By setting the above structure, the positions of the adjustment frame and the second rolling cylinder can be adjusted, so that the second rolling cylinder can control the self-propelling plate to rotate.

[0018] Preferably, the second rolling column is in close contact with the left side surface of the self-propelling plate, and the self-propelling plate forms a rotating structure through the second rolling column.

[0019] Through the arrangement of the above structure, the second rolling column can reduce the contact area with the self-propelled plate, thereby reducing the friction between the second rolling column and the self-propelled plate, so as to protect the second rolling column and the self-propelled plate, thereby increasing the service life of the second rolling column and the self-propelled plate.

[0020] Preferably, the left end of the threaded rod is connected to an external motor through a coupling.

[0021] Through the arrangement of the above structure, the motor can automatically drive the threaded rod to rotate.

[0022] Preferably, a distance measuring sensor is installed in a groove inside the right side surface of the brake shoe body for detecting the gap between the brake shoe body and the wheel tread.

[0023] Through the arrangement of the above structure, the distance measuring sensor can well detect the gap between the brake shoe body and the wheel tread, so as to facilitate the later control of the movement of the adjustment frame, so that the self-pushing plate automatically pushes the brake shoe body to automatically adjust the gap between the brake shoe body and the wheel tread.

[0024] Compared with the prior art, the invention has the following beneficial effects: the anti-eccentric wear device for the brake shoe of the locomotive brake can avoid eccentric wear caused by deviation, and ensure that the brake shoe body can accurately contact the wheel tread in the later stage. The specific contents are as follows: (1) The guide block in the guide mechanism slides in the guide groove, so that precise guidance can ensure that the brake shoe body moves along the correct trajectory during braking and release, avoiding eccentric wear due to deviation and ensuring that the brake shoe body can accurately contact the wheel tread in the later stage; Furthermore, by installing multiple sets of elastic adjustment mechanisms between the brake shoe bracket and the brake shoe body, the return spring in the elastic adjustment mechanism can be deformed accordingly, and the pressure can be dispersed to other parts of the brake shoe body, so that the force at each position of the brake shoe body can be more uniform, ensuring that the wear of each part of the brake shoe body is relatively balanced, so that the entire friction surface of the brake shoe body can be fully utilized, the braking efficiency can be improved, and the service life of the brake shoe can be extended; (2) During the braking process, when the brake shoe body wears and the gap gradually increases, the use of the self-pushing plate and the connecting spring in the automatic gap adjustment mechanism can always apply a thrust to the brake shoe body, so that the brake shoe body and the wheel tread maintain an appropriate gap, ensuring that all positions of the brake shoe body wear evenly; Furthermore, the second rolling column is driven to move by the adjustment frame so that the second rolling column can apply a thrust to the self-push plate, thereby ensuring that the self-push plate stably applies a thrust to the brake shoe body, thereby ensuring the stability of the brake shoe body after the position is adjusted, so that the brake shoe body and the wheel tread maintain an appropriate gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a left-side stereoscopic structural schematic diagram of the present invention; Figure 2 It is a right-side stereoscopic structural schematic diagram of the present invention; Figure 3 It is a schematic diagram of the main structure of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure of the connecting sleeve of the present invention; Figure 5 This is a schematic diagram of the main cross-sectional structure of the connecting sleeve of the present invention; Figure 6 For the present invention Figure 5 The enlarged structural diagram at A in the middle; Figure 7 It is a schematic diagram of the three-dimensional structure of the self-propelling plate of the present invention.

[0026] In the figure: 1. brake shoe bracket; 2. connecting spring; 3. connecting block; 4. brake shoe body; 5. self-pushing plate; 51. first rolling column; 52. rotating rod; 53. vortex spring; 6. adjusting frame; 7. second rolling column; 8. connecting sleeve; 9. threaded rod; 10. guide groove; 11. guide block; 12. adjusting column; 13. reset spring; 14. ball. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1-Figure 7 , the present invention provides the following technical solutions: Embodiment 1: The anti-eccentric wear device for the brake shoe of the locomotive brake machine in this embodiment can ensure that the brake shoe body 4 is in accurate contact with the wheel tread when in use, so that each position of the brake shoe body 4 is evenly stressed, thereby avoiding eccentric wear of the brake shoe body 4. The specific structure is shown in the attached Figure 1-Figure 6 As shown, it includes a brake shoe bracket 1, and a brake shoe body 4 installed on the right side of the brake shoe bracket 1 through a guide mechanism, the right sides of the upper and lower ends of the brake shoe bracket 1 are installed with elastic adjustment mechanisms, and the end of the elastic adjustment mechanism away from the brake shoe bracket 1 is arranged in contact with the left side of the brake shoe body 4, and the front and rear side surfaces of the upper and lower ends of the brake shoe bracket 1 are symmetrically installed with gap automatic adjustment mechanisms for adjusting the position of the brake shoe body 4. The middle part of the brake shoe bracket 1 is arranged in a "U" shape, and the upper and lower ends of the brake shoe bracket 1 are arranged in an arc shape. The guide mechanism includes symmetrical openings on the brake shoe A guide groove 10 is provided in the middle of the bracket 1, a connecting block 3 is installed on the left side of the brake shoe body 4, guide blocks 11 are symmetrically installed on the upper and lower sides of the connecting block 3, the outer side of the guide block 11 is slidably connected to the guide groove 10, and the left side of the connecting block 3 is connected to the inside of the brake shoe bracket 1 through the connecting spring 2. The elastic adjustment mechanism includes a connecting sleeve 8 connected to the brake shoe bracket 1, and also includes an adjusting column 12 slidably connected in the connecting sleeve 8 through a reset spring 13. A ball 14 is installed on the outer end of the adjusting column 12, and the ball 14 is in close contact with the left side surface of the brake shoe body 4.

[0029] First, connect the left side of the brake shoe bracket 1 to the electric push rod in the locomotive brake machine. Then, when the locomotive needs to slow down or stop, start the electric push rod, which drives the brake shoe bracket 1 and the brake shoe body 4 to move to the right. When the right side of the brake shoe body 4 fits the wheel tread, the brake shoe bracket 1 continues to move to the right. At this time, the guide blocks 11 on the upper and lower sides of the connecting block 3 slide in the guide groove 10, and the connecting spring 2 is squeezed and stored. At this time, the guide blocks 11 slide in the guide groove 10 to limit the guide, so that the brake shoe body 4 always moves along the correct trajectory during braking and relief, avoiding eccentric wear of the brake shoe body 4 and the wheel tread due to offset, thereby ensuring that the brake shoe body 4 is accurately in contact with the wheel tread. The side ball 14 is fitted with the left side surface of the brake shoe body 4, and the other end of the adjusting column 12 enters into the connecting sleeve 8 to squeeze and store force on the return spring 13, so that the brake shoe bracket 1 applies a rightward thrust to the brake shoe body 4, so that the brake shoe body 4 is closely fitted and contacted with the wheel tread, so that the wheel tread is slowed down or stopped. In this process, when a part of the brake shoe body 4 is subjected to greater pressure, the pressure can be dispersed to other parts of the brake shoe body 4 through the deformation of the return spring 13, so that each position of the brake shoe body 4 is evenly stressed and the degree of wear of each position of the brake shoe body 4 is the same. Therefore, not only the service life of the brake shoe body 4 can be improved, but also the entire friction surface of the brake shoe body 4 can be fully utilized to improve the braking efficiency.

[0030] When there is no need to slow down or stop the locomotive, the electric push rod is started, which drives the brake shoe bracket 1 and the brake shoe body 4 to move to the left. At this time, the brake shoe body 4 is reset by the stored force of the connection spring 2 to facilitate the next use.

[0031] Embodiment 2: The anti-eccentric wear device for the brake shoe of the locomotive brake machine in this embodiment can always apply a thrust to the brake shoe body 4 so that the brake shoe body 4 and the wheel tread maintain a suitable gap. The specific structure is shown in the attached Figure 1 , Figure 5As shown, the automatic gap adjustment mechanism includes a rotating rod 52 installed on the front and rear sides of the upper and lower ends of the brake shoe bracket 1, and an arc-shaped self-pushing plate 5 is fixed on the outer side of the rotating rod 52. A vortex spring 53 is nested and connected to the outer side of the rotating rod 52 close to the brake shoe bracket 1, and the other end of the vortex spring 53 is connected to the brake shoe bracket 1. A first rolling column 51 is rotatably installed inside the end of the self-pushing plate 5 away from the rotating rod 52. The first rolling column 51 is in contact with the left side of the brake shoe body 4, and the brake shoe body 4 forms a sliding structure through the self-pushing plate 5. On the basis of Example 1, when the brake shoe body 4 moves to the right and is in contact with the wheel tread, the self-pushing plate 5 will rotate through the stored force of the vortex spring 53, so that The first rolling column 51 on the outer side of the self-push plate 5 is always in contact with the left side of the brake shoe body 4. At this time, the self-push plate 5 can apply a rightward thrust to the brake shoe body 4. At the same time, the connecting spring 2 and the return spring 13 will also apply a rightward thrust to the brake shoe body 4, so that the brake shoe body 4 is stably in contact with the wheel tread. In this way, during the braking process, due to the wear between the brake shoe body 4 and the wheel tread, the gap between the brake shoe body 4 and the wheel tread gradually increases. At this time, the connecting spring 2, the return spring 13 and the self-push plate 5 will all apply a rightward thrust to the brake shoe body 4, so that the brake shoe body 4 is stably in contact with the wheel tread, ensuring that all positions of the brake shoe body 4 are evenly worn.

[0032] Embodiment 3: The anti-eccentric wear device for the brake shoe of the locomotive brake machine in this embodiment can further ensure the stability of the brake shoe body 4 after the movement, and facilitate the adjustment of the gap between the brake shoe body 4 and the wheel tread. Figure 5As shown, on the basis of the second embodiment, the upper and lower side surfaces of the middle area of ​​the brake shoe bracket 1 are grooved and installed with threaded rods 9, the outer side of the threaded rod 9 is threadedly connected with an adjusting frame 6, the upper end of the adjusting frame 6 is connected with a second rolling column 7, the second rolling column 7 is in close contact with the left side of the self-propelled plate 5, and the self-propelled plate 5 forms a rotating structure through the second rolling column 7, the left end of the threaded rod 9 is connected to an external motor through a coupling, and a distance measuring sensor is grooved and installed on the right side of the brake shoe body 4 for detecting the gap between the brake shoe body 4 and the wheel tread, the left end of the threaded rod 9 is connected to an external motor, and the distance measuring sensor is grooved and installed in the brake shoe body 4 (since this part is the prior art, the distance measuring sensor is not drawn in the figure, and this part is not introduced in detail), when the vortex spring 53, the connecting spring 2 and the return spring 13 are used for a long time and their elasticity fails and is damaged, at this time the vortex spring 53, the connecting spring 2 and the return spring 13 are The positioning spring 13 cannot apply a rightward thrust to the brake shoe body 4 well, which will make the brake shoe body 4 unable to stably fit and contact with the wheel tread. At this time, the distance measuring sensor installed in the brake shoe body 4 can be used to monitor the distance between the brake shoe body 4 and the wheel tread. When it is monitored that the gap between the brake shoe body 4 and the wheel tread gradually increases due to wear, the motor can be started to drive the threaded rod 9 to rotate. When the threaded rod 9 rotates, it drives the outer adjusting frame 6 to move to the right. At this time, the second rolling column 7 at the right end of the adjusting frame 6 fits with the self-pushing plate 5 and applies a rightward thrust to the self-pushing plate 5. At this time, the self-pushing plate 5 rotates with the rotating rod 52 as the center of the circle, so that the first rolling column 51 at the outer end of the self-pushing plate 5 applies a rightward thrust to the brake shoe body 4, and then the brake shoe body 4 moves well to the right and fits closely with the wheel tread, ensuring the stability of the brake shoe body 4 after the position adjustment, so that the brake shoe body 4 and the wheel tread maintain a suitable gap.

[0033] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-eccentric wear device for a brake shoe of a locomotive brake, comprising a brake shoe bracket (1), and a brake shoe body (4) mounted on the right side of the brake shoe bracket (1) through a guide mechanism, characterized in that: The right sides of the upper and lower ends of the brake shoe bracket (1) are both equipped with elastic adjustment mechanisms, and one end of the elastic adjustment mechanism away from the brake shoe bracket (1) is arranged in contact with the left side of the brake shoe body (4). The front and rear side surfaces of the upper and lower ends of the brake shoe bracket (1) are both symmetrically equipped with automatic clearance adjustment mechanisms for adjusting the position of the brake shoe body (4).

2. The anti-eccentric wear device for brake shoe of a locomotive brake according to claim 1, characterized in that: The middle portion of the brake shoe bracket (1) is arranged in a "U" shape, the upper and lower ends of the brake shoe bracket (1) are arranged in an arc shape, and the guide mechanism comprises guide grooves (10) symmetrically arranged in the middle portion of the brake shoe bracket (1).

3. The anti-eccentric wear device for brake shoe of a locomotive brake according to claim 2, characterized in that: A connecting block (3) is installed on the left side of the brake shoe body (4), and guide blocks (11) are symmetrically installed on the upper and lower sides of the connecting block (3). The outer side of the guide block (11) is slidably connected to the guide groove (10), and the left side of the connecting block (3) is connected to the inside of the brake shoe bracket (1) through a connecting spring (2).

4. The anti-eccentric wear device for brake shoe of a locomotive brake according to claim 1, characterized in that: The elastic adjustment mechanism comprises a connecting sleeve (8) connected to the brake shoe bracket (1), and also comprises an adjustment column (12) slidably connected to the connecting sleeve (8) via a return spring (13), a ball (14) being mounted on the outer end of the adjustment column (12), and the ball (14) is in close contact with the left side surface of the brake shoe body (4).

5. The anti-eccentric wear device for brake shoe of a locomotive brake according to claim 1, characterized in that: The automatic gap adjustment mechanism comprises a rotating rod (52) mounted on the front and rear side surfaces of the upper and lower ends of the brake shoe bracket (1); an arc-shaped self-pushing plate (5) is fixedly passed through the outer side of the rotating rod (52); a vortex spring (53) is nested and connected to the outer side of one end of the rotating rod (52) close to the brake shoe bracket (1); the other end of the vortex spring (53) is connected to the brake shoe bracket (1); a first rolling column (51) is rotatably mounted inside the end of the self-pushing plate (5) away from the rotating rod (52); the first rolling column (51) is in close contact with the left side surface of the brake shoe body (4).

6. The anti-eccentric wear device for brake shoe of a locomotive brake according to claim 1, characterized in that: The brake shoe body (4) forms a sliding structure through the self-pushing plate (5).

7. The anti-eccentric wear device for brake shoes of a locomotive brake according to claim 1, characterized in that: The upper and lower side surfaces of the middle region of the brake shoe bracket (1) are grooved to install a threaded rod (9), the outer side of the threaded rod (9) is threadedly connected to an adjustment frame (6), and the upper end of the adjustment frame (6) is connected to a second rolling column (7).

8. The anti-eccentric wear device for brake shoe of a locomotive brake according to claim 7, characterized in that: The second rolling column (7) is in close contact with the left side surface of the self-propelling plate (5), and the self-propelling plate (5) forms a rotating structure through the second rolling column (7).

9. The anti-eccentric wear device for brake shoes of a locomotive brake according to claim 7, characterized in that: The left end of the threaded rod (9) is connected to an external motor via a coupling.

10. The anti-eccentric wear device for brake shoes of a locomotive brake according to claim 1, characterized in that: A distance measuring sensor is installed in a groove inside the right side surface of the brake shoe body (4) for detecting the gap between the brake shoe body (4) and the wheel tread.

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