CN210397537U

CN210397537U - Wear indicator for drum brake

Info

Publication number: CN210397537U
Application number: CN201921482823.7U
Authority: CN
Inventors: 黄美华
Original assignee: Zhejiang Olympic Machinery Ltd By Share Ltd
Current assignee: Zhejiang Olympic Machinery Ltd By Share Ltd
Priority date: 2019-09-07
Filing date: 2019-09-07
Publication date: 2020-04-24
Anticipated expiration: 2029-09-07

Abstract

The utility model provides a drum brake is with wear indicator belongs to vehicle accessory technical field. The abrasion indicator solves the problems that the existing abrasion indicator for the drum brake cannot timely distinguish which friction lining is abraded and the like. The wear indicator for the drum brake comprises a shell and a rotary disc, wherein the rotary disc is axially limited in the shell and can rotate, a through connecting hole is formed in the center of the rotary disc, an on-off switch is arranged in the shell, the rotary disc is provided with a protruding portion used for triggering the on-off switch, the shell is connected with a standard wiring harness connected with the on-off switch, an alarm lamp connected with the on-off switch is arranged on the shell, and the alarm lamp emits light after the protruding portion triggers the on-off switch. The utility model has the advantages of can directly reflect out and need to change friction facing position.

Description

Wear indicator for drum brake

Technical Field

The utility model belongs to the technical field of the vehicle accessory, a drum brake accessory is related to, in particular to drum brake is with wear indicator.

Background

According to the requirements of GB7258-2017 article 7.9.5: when the lining of the service brake needs to be replaced, an optical or acoustic alarm device is adopted to give an alarm to a driver on a driver seat, and meanwhile, the vehicle with the drum brake, which meets the above conditions, is required to be implemented from 1 month and 1 day in 2020.

As the cam shaft of the drum brake rotates when the friction lining is worn, a wear indicator that can rotate synchronously with the cam shaft is proposed, and for example, chinese patent literature discloses a wear alarm device for a friction plate of a drum brake [ application No.: 201821686095.7, respectively; authorization notice number: CN208935238U ], it includes that shell and axial are spacing in the shell and can the pivoted carousel, the carousel center runs through and is provided with the connecting hole, be equipped with on-off switch in the shell, the part that the carousel is located the shell is equipped with the bulge that can trigger on-off switch, be equipped with convex connecting portion on the connecting hole inner wall or the carousel back, the indicating mark has on the shell, the rotation mark has on the carousel, it aligns with the indicating mark to rotate the mark when the carousel rotates to the bulge triggers on-off switch, the assembly sign has on the shell, the installation sign that can align with the assembly sign has on the carousel.

When the drum brake friction plate abrasion alarm device is used, a driver can directly know the abrasion condition of the friction lining from the outside through the rotating mark and the indicating mark, and the assembling accuracy can be guaranteed through the assembling mark and the installing mark so as to guarantee the alarm accuracy.

Disclosure of Invention

The utility model aims at the above-mentioned problem that exists among the prior art, provide one kind and can directly reflect the drum brake that needs to change the friction lining position and use the wear indicator after the wearing and tearing warning appears.

The purpose of the utility model can be realized by the following technical proposal: the utility model provides a drum brake is with wear indicator, includes casing and carousel, the carousel axial spacing in the casing and can rotate, the carousel center be equipped with the connecting hole that runs through, the casing in be equipped with on-off switch, the carousel have the bulge that is used for triggering on-off switch, the casing be connected with the standard pencil that links with on-off switch, its characterized in that, the casing on be equipped with the alarm lamp that links with on-off switch, work as the bulge trigger behind the on-off switch the alarm lamp luminous.

The on-off switch in the wear indicator for the drum brake is in a normally closed state, so that the problem of 'failure to report' caused by open circuit is solved; this drum brake is with wearing and tearing indicator installation, the casing is connected on the automatic adjustment arm, the carousel passes through the connecting hole and is fixed with drum brake's camshaft, the camshaft drives the carousel rotation, when the friction lining wearing and tearing of drum brake are to the extreme value, bulge on the carousel triggers on-off switch, on-off switch opens and passes through standard pencil with signal of telecommunication to driver's cabin, report to the police to the driver through the sound light, on-off switch opens and makes the alarm lamp luminous simultaneously, directly react out the position that needs to change the friction lining through light like this, be convenient for the driver, the direct observation of maintainer, the wheel that pulls out that has saved to waste time and energy detects, maintenance cost has been reduced.

In the wear indicator for a drum brake, the housing has a cavity for accommodating the warning lamp, and the housing is fixedly connected with a cover plate which covers the cavity and can transmit light. The apron can not block the light that the alarm lamp sent, and the apron plays the guard action, avoids the filth to cause alarm lamp and on-off switch to damage, has prolonged life.

In the wear indicator for a drum brake, the dial is provided with an indication mark, and the housing is provided with a display mark which is matched with the indication mark to display the wear condition. Therefore, in the using process, a driver can know the wear condition of the friction lining conveniently through the indicating mark and the display mark.

In the wear indicator for a drum brake, the protruding portion is an arc-shaped protruding block, a slope surface gently inclined from one end of the protruding block to the other end of the protruding block is arranged on the end surface of the protruding block facing the on-off switch, the highest position of the slope surface is used for triggering the on-off switch, the display mark is a plurality of scale marks evenly distributed at intervals, each scale mark has a corresponding numerical value for displaying the thickness of the friction lining, the larger the numerical value is, the larger the distance from the slope surface to the on-off switch is, and the indication mark is a line or an arrow.

Drum brake of different models has the friction lining of different thickness, scale mark and numerical display friction lining's effective thickness, as long as rotate the carousel make the directional effective thickness that corresponds to the friction lining that drum brake has can, later the carousel rotates along with the camshaft, the pilot mark is close to minimum numerical value more, when the directional minimum numerical value of pilot mark, domatic highest point triggers on-off switch, this drum brake is with wear indicator can be applicable to the drum brake of different models like this, therefore, the commonality is strong, and the directional scale mark of pilot mark and numerical value can the remaining effective thickness of visual display friction lining, be convenient for the driver to learn the wearing and tearing condition of friction lining.

In the wear indicator for a drum brake described above, the housing is fastened to a cover which blocks an edge of the disc, the disc being located between the housing and the cover. Thus, the assembly is convenient.

In the above wear indicator for a drum brake, the rotary disc includes a plastic disc and a metal disc both having a ring shape, the plastic disc has the protruding portion, the metal disc has the indicating mark, an edge of the metal disc is blocked by the housing cover, the metal disc and the plastic disc are connected integrally, and an inner diameter of the metal disc is smaller than an inner diameter of the plastic disc. The manufacturing is convenient, the metal disc and the camshaft are fixed so as to avoid abrasion and deformation, the work is stable, and the service life is long.

In the wear indicator for a drum brake, the metal disc has a circle of convex step part, and the plastic disc has a limit boss which is convex and embedded in the step part.

In the wear indicator for a drum brake, the shell cover is embedded with a first sealing ring sealed on the metal disc, the shell cover is embedded with a second sealing ring sealed on the shell, and the shell is embedded with a third sealing ring sealed on the plastic disc. The sealing performance between cap and the metal disc has been guaranteed to sealing washer one, and the sealing performance between cap and the casing has been guaranteed to sealing washer two, and the sealing performance between casing and the plastics dish has been guaranteed to sealing washer three, avoids impurity entering and causes wearing and tearing or cause the carousel to rotate inconveniently, also avoids impurity entering casing and causes the on-off switch to damage, has guaranteed job stabilization nature.

In the above wear indicator for a drum brake, the housing and/or the cover plate has a directional arrow indicating the mounting direction. The direction arrow is consistent with the direction of the arrow on the automatic adjusting arm, so that installation errors are avoided.

Compared with the prior art, the wear indicator for the drum brake has the following advantages:

1. through the arrangement of the on-off switch, the alarm sensor and the alarm lamp, which wheel end alarms and the abrasion state of the friction linings of each wheel end can be visually observed, so that time-consuming and labor-consuming wheel pulling detection is avoided, and the maintenance cost is reduced; 2. the material can be repeatedly used, the use cost is low, the waste is reduced, the pollution is reduced, and the cost performance is high; 3. the drum brake is far away from the wheel end after installation, the drum brake cannot be influenced by high temperature, the durability of the on-off switch reaches more than one hundred thousand times, the service life is long, the normally closed design is adopted, the problem that the alarm is not reported due to circuit breaking is avoided, and the working stability is good; 4. the wear indicator for the drum brake has the advantages that the wear indicator is configured with the EBS system in the later period, the size of the wear indicator for the drum brake can be completely universal, the wear indicator does not need to be designed and replaced, and the use cost is reduced; 5. when the turntable is rotated, the alarm lamp emits light normally, otherwise, the alarm lamp is damaged, and a user can easily judge whether the product is normal; 6. the installation is convenient and reliable.

Drawings

Fig. 1 is a front view of the wear indicator for a drum brake according to the present invention.

Fig. 2 is a structural sectional view of the wear indicator for a drum brake according to the present invention.

Fig. 3 is a front view of the structure of a dial in the wear indicator for a drum brake according to the present invention.

Fig. 4 is a structural sectional view of a dial in the wear indicator for a drum brake according to the present invention.

In the figure, 1, a housing; 2. a turntable; 21. a projection; 22. a slope surface; 23. a plastic tray; 231. a limiting boss; 24. a metal disc; 241. a step portion; 3. an on-off switch; 4. a standard wire harness; 5. an alarm lamp; 6. a cover plate; 7. an indicator mark; 8. displaying the mark; 81. scale lines; 82. a numerical value; 9. a shell cover; 10. a first sealing ring; 11. a second sealing ring; 12. a third sealing ring; 13. directional arrows.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

As shown in fig. 1 and 2, the wear indicator for the drum brake comprises a shell 1 and a rotary disc 2, wherein the rotary disc 2 is axially limited in the shell 1 and can rotate, a through connecting hole is formed in the center of the rotary disc 2, an on-off switch 3 is arranged in the shell 1, the rotary disc 2 is provided with a protruding part 21 for triggering the on-off switch 3, the shell 1 is connected with a standard wiring harness 4 connected with the on-off switch 3, an alarm lamp 5 connected with the on-off switch 3 is arranged on the shell 1, and when the protruding part 21 triggers the on-off switch 3, the alarm lamp 5 emits light; in the embodiment, the alarm lamp 5 emits red light to be easily found, the on-off switch 3 is connected with the alarm lamp 5 and the standard wiring harness 4 through the circuit board, the circuit on the circuit board is a series circuit which connects the on-off switch 3, the alarm lamp 5 and the standard wiring harness 4 in series, and the on-off switch 3 is in a normally closed state.

In more detail, the shell 1 is provided with a cavity for accommodating the alarm lamp 5, the shell 1 is fixedly connected with a cover plate 6 which covers the cavity and can transmit light, and the cover plate 6 is a plastic cover in the embodiment; the turntable 2 is provided with an indication mark 7, and the shell 1 is provided with a display mark 8 which is matched with the indication mark 7 to display the abrasion condition; as shown in fig. 3 and 4, the protruding portion 21 is an arc-shaped protruding block, the end surface of the protruding block facing the on-off switch 3 is provided with a slope 22 gently inclined from one end of the protruding block to the other end of the protruding block, the highest position of the slope 22 is used for triggering the on-off switch 3, the display mark 8 is a plurality of lines 81 evenly distributed at intervals, each line 81 has a corresponding value 82 for displaying the thickness of the friction lining, the larger the value 82 is, the larger the distance between the slope 22 and the on-off switch 3 is, the indication mark 7 is a score line or an arrow, the indication mark 7 is an arrow in the present embodiment, eight lines 81 are provided, the value 82 is an arabic number sequentially arranged from "2" to "9", the value 822 is that the friction lining has reached the wear limit of 2mm, and the other values 82 are the effective thickness of the friction lining.

For convenient assembly, the shell 1 is buckled with a shell cover 9 which blocks the edge of the rotating disc 2, and the rotating disc 2 is positioned between the shell 1 and the shell cover 9; for manufacturing convenience and working stability, the rotary table 2 comprises a plastic disc 23 and a metal disc 24 which are both annular, the plastic disc 23 is provided with a convex part 21, the metal disc 24 is provided with an indication mark 7, the edge of the metal disc 24 is blocked by a cover 9, the metal disc 24 and the plastic disc 23 are connected into a whole, the inner diameter of the metal disc 24 is smaller than that of the plastic disc 23, the inner diameter of the metal disc 24 is provided with an internal spline matched with a cam shaft in the embodiment, and the metal disc 24 and the plastic disc 23 are bonded into a whole; for limiting to facilitate bonding, the metal disc 24 has a circle of convex step parts 241, and the plastic disc 23 has a limiting boss 231 which is convex and embedded in the step parts 241; in order to have good sealing performance and avoid the damage of internal parts caused by impurities and dirt, a first sealing ring 10 sealed on the metal disc 24 is embedded in the shell cover 9, a second sealing ring 11 sealed on the shell body 1 is embedded in the shell cover 9, and a third sealing ring 12 sealed on the plastic disc 23 is embedded in the shell body 1; the housing 1 and/or the cover 6 have a directional arrow 13 indicating the mounting direction, and in the present embodiment both the housing 1 and the cover 6 have a directional arrow 13 indicating the mounting direction.

Selecting spline parameters matched with the wear indicator for the drum brake with a left model and a right model, measuring the effective thickness of a friction lining to be assembled, rotating the metal disc 24 according to the measured effective thickness to enable the indication mark 7 to be aligned with a corresponding scale mark 81 and a corresponding numerical value 82, then rotating the automatic adjusting arm in the anticlockwise direction until the cam shaft reaches a zero position, then installing the wear indicator for the drum brake on the spline of the cam shaft, namely, the metal disc 24 is meshed with the cam shaft, the direction arrow 13 points to be consistent with the direction of the arrow on the automatic adjusting arm, when installing the wear indicator for the drum brake, the position of the metal disc 24 cannot be changed, the shell 1 is provided with a strip-shaped hole to facilitate the movement of a fixing bolt to align the fixing position, then installing a gasket and a clamp spring on the cam shaft to ensure that the clearance value between the wear indicator for the drum brake and the automatic adjusting arm is between 0.5mm and 1.0mm, and then, locking the fixing bolt by using a spanner to fix, then, rotating the adjusting bolt of the automatic adjusting arm clockwise by using the spanner until the friction lining and the brake drum are locked, finally, rotating the adjusting bolt of the automatic adjusting arm for more than 3/4 circles by using the spanner in the anticlockwise direction, starting the vehicle, and stepping on the brake for more than 30 times, namely, finishing the installation.

When the device is used, the cam shaft drives the metal disc 24 and the plastic disc 23 to rotate together, until the friction lining of the drum brake is worn to the limit value, the protrusion part 21 triggers the on-off switch 3, the on-off switch 3 is turned on and transmits a signal to a cab through the standard wire harness 4, the driver is warned through sound light, and the warning lamp 5 is turned on and made to emit light at the same time, so that the position of the friction lining needing to be replaced is directly reflected through light, the driver and maintenance personnel can conveniently and directly observe the position, time-consuming and labor-consuming wheel pulling detection is omitted, and maintenance cost is reduced; of course, before the alarm is not given, the residual effective thickness of the friction lining can be visually displayed by observing the positions of the indication mark 7 pointing to the scale mark 81 and the numerical value 82, so that a driver can know the abrasion condition of the friction lining conveniently.

Those not described in detail in this specification are within the skill of the art. The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Claims

1. The utility model provides a drum brake is with wear indicator, includes casing (1) and carousel (2), carousel (2) axial spacing in casing (1) and can rotate, carousel (2) center be equipped with the connecting hole that runs through, casing (1) in be equipped with on-off switch (3), carousel (2) bulge (21) that are used for triggering on-off switch (3) have, casing (1) be connected with standard pencil (4) that link with on-off switch (3), its characterized in that, casing (1) on be equipped with alarm lamp (5) that link with on-off switch (3), work as bulge (21) trigger behind on-off switch (3) alarm lamp (5) give out light.

2. A wear indicator for a drum brake according to claim 1, characterised in that the housing (1) has a chamber for receiving a warning light (5), and that the housing (1) has attached thereto a cover plate (6) which covers the chamber and is light-transmissive.

3. A wear indicator for a drum brake according to claim 1 or 2, characterised in that the turntable (2) is provided with indication marks (7) and the housing (1) is provided with indication marks (8) cooperating with the indication marks (7) to indicate the wear.

4. A wear indicator for a drum brake according to claim 3, characterised in that the protrusion (21) is an arc-shaped projection, the end surface of the projection facing the on-off switch (3) has a slope (22) sloping gently from one end of the projection to the other end of the projection, the highest point of the slope (22) is used for triggering the on-off switch (3), the display marks (8) are a plurality of evenly spaced graduation marks (81), each graduation mark (81) has a corresponding value (82) for displaying the thickness of the friction lining, a larger value (82) indicates a larger distance between the slope (22) and the on-off switch (3), and the indication mark (7) is a line or an arrow.

5. A wear indicator for a drum brake according to claim 4, characterised in that the housing (1) is snap-fitted with a cover (9) that blocks the edge of the disc (2), the disc (2) being located between the housing (1) and the cover (9).

6. A wear indicator for a drum brake according to claim 5, characterised in that the disc (2) comprises a plastic disc (23) and a metal disc (24) both in the form of a ring, the plastic disc (23) having the protrusion (21), the metal disc (24) having the indicating mark (7), the edge of the metal disc (24) being blocked by the cover (9), the metal disc (24) and the plastic disc (23) being integral and the metal disc (24) having an internal diameter smaller than the internal diameter of the plastic disc (23).

7. A wear indicator for a drum brake according to claim 6, in which the metal disc (24) has a ring of outwardly projecting steps (241), and the plastic disc (23) has a stop boss (231) which is outwardly projecting and is embedded in the steps (241).

8. A wear indicator for a drum brake according to claim 7, characterised in that the housing cover (9) is fitted with a first seal (10) for sealing against a metal disc (24), the housing cover (9) is fitted with a second seal (11) for sealing against the housing (1), and the housing (1) is fitted with a third seal (12) for sealing against a plastic disc (23).

9. A wear indicator for a drum brake according to claim 2, characterised in that the housing (1) and/or the cover plate (6) have/has a directional arrow (13) indicating the mounting direction.