Disc brake friction pad wear detection device and vehicle

Abstract

The present application discloses a disc brake friction pad detection device and a vehicle, comprising: a hydraulic brake caliper body, a piston, a screw, and a threaded sleeve. The piston is disposed within the hydraulic brake caliper body of the hydraulic disc brake assembly, the threaded sleeve is fixed to the end face of the hydraulic brake caliper body, one end of the screw passes through the threaded sleeve and engages with the piston, and the other end of the screw is provided with a sliding rheostat. In an embodiment of the present application, one end of the screw of the hydraulic disc brake engages with the piston, and when the friction pad is worn, the clearance is self-adjusted. When the position of the piston within the hydraulic brake caliper body is changed, the screw follows the piston to generate axial displacement, thereby converting the axial displacement of the screw into an electrical signal using the sliding rheostat. The electrical signal reflects the degree of wear of the friction pad in the hydraulic disc brake, thereby achieving accurate detection of the friction pad in the hydraulic disc brake, reducing the complexity of the detection structure, and enabling timely inspection of the wear of the friction pad during non-braking operations, thereby ensuring the driving safety of the vehicle.

Description

Technical Field

[0001] The present invention generally relates to the field of automobile technology, and in particular to a disc brake friction pad wear detection device and a vehicle. Background Art

[0002] Brakes are a crucial safety feature in modern vehicles and are widely used on a wide range of vehicles. Failure to promptly replace worn brake pads can lead to a significant drop in braking torque and an imbalance in braking torque between the left and right wheels. This can cause serious braking issues such as long braking distances and swerving, posing a significant risk to driving safety.

[0003] Currently, in disc brakes, in order to accurately measure the wear of the brake friction pad, a sensor is configured on one of the push-disk drivers. When the brake is adjusted due to a decrease in the thickness of the friction pad, the sensor synchronously sends a voltage signal of the friction pad thickness to the electronic control unit, thereby monitoring the friction pad thickness. The electronic control unit will distribute the braking force through calculation, thereby reducing the occurrence of excessive wear of the friction pad on the front or rear axle due to the center of gravity problem of the vehicle.

[0004] The existing disc brake friction pad detection device is mainly used for friction pad wear detection of pneumatic disc brakes and cannot be applied to hydraulic brakes. In addition, the structure has many parts and is complex, resulting in high cost and difficult maintenance. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a disc brake friction pad detection device and a vehicle, which can detect the axial displacement of the screw by cooperating with the screw and the piston to reduce the complexity of the disc brake friction pad wear detection structure.

[0006] In a first aspect, an embodiment of the present application provides a disc brake friction pad wear detection device, comprising:

[0007] A hydraulic brake caliper body, a piston, a screw and a threaded sleeve. The piston is arranged in the hydraulic brake caliper body, and the threaded sleeve is fixed on the end face of the hydraulic brake caliper body. One end of the screw passes through the threaded sleeve and cooperates with the piston, so that when the hydraulic disc brake performs clearance self-adjustment, the screw and the piston undergo synchronous axial displacement.

[0008] The other end of the screw is provided with a sliding rheostat, which is used to convert the axial displacement of the screw into an electrical signal, and the electrical signal is used to indicate the degree of wear of the friction plate in the hydraulic disc brake.

[0009] Optionally, in some embodiments, the screw is provided with a first bearing near one end of the piston, and a second bearing is provided on the inner wall of the piston. The first bearing and the second bearing are coaxially arranged, and the first bearing is closer to the end where the screw and the piston cooperate than the second bearing. A conical spring is provided between the first bearing and the second bearing.

[0010] Optionally, in some embodiments, a first sealing ring is arranged between the piston and the hydraulic brake caliper body, a second sealing ring is arranged between the screw and the piston, and a third sealing ring is arranged between the screw and the nut.

[0011] Optionally, in some embodiments, a sealing groove is provided at one end of the screw rod that cooperates with the piston, and the second sealing ring is disposed in the sealing groove.

[0012] Optionally, in some embodiments, the screw rod is configured as a conical structure at one end close to the piston, and the middle portion of the screw rod is configured with a thread that cooperates with the threaded sleeve.

[0013] Optionally, in some embodiments, a boss is configured on the conical structure of the screw, and an oil hole is provided on the boss.

[0014] Optionally, in some embodiments, a circumferential retaining ring is provided on the inner wall of the piston close to the conical structure, and the retaining ring is located between the boss and the first bearing.

[0015] Optionally, in some embodiments, a positioning groove is provided on the contact end surface of the piston and the friction plate, and a sealing groove is provided on the outer circumferential surface of the piston, wherein a vent hole is provided at the sealing groove.

[0016] Optionally, in some embodiments, the gap between the brake disc and the friction plate in the hydraulic disc brake is a first distance, the thread fitting clearance of the screw and the sleeve is a second distance, the limit deformation of the first sealing ring after assembly is a third distance, the assembly clearance of the screw and the retaining ring is a fourth distance, the length of the screw extending from the sleeve is a fifth distance, the thread fitting length of the screw and the sleeve is a sixth distance, and the limit wear of the brake disc and the friction plate is a seventh distance. Then, the fitting clearance of the hydraulic disc brake satisfies:

[0017] The first distance ≤ the second distance ≤ the third distance ≤ the fourth distance < the fifth distance < the sixth distance < the seventh distance.

[0018] Optionally, in some embodiments, the sliding rheostat includes a shell, a resistor and a brush. The shell is arranged on the end face of the sleeve away from the piston, the resistor is fixed in the side wall of the shell, and the brush is arranged on the screw. The brush moves with the screw and slides into contact with the resistor.

[0019] Optionally, in some embodiments, a connector is disposed on the housing, and the connector includes a positive line, a signal line, and a negative line. The signal line is connected to the brush, and the positive line and the negative line are connected to both ends of the resistor.

[0020] Optionally, in some embodiments, a connecting hole is provided on the end surface of the shell away from the screw sleeve, and the other end of the screw rod is provided with a hexagonal hole for cooperating with the connecting hole.

[0021] Optionally, in some embodiments, a plug that cooperates with the connecting hole is disposed on the end surface of the shell away from the screw sleeve.

[0022] In a second aspect, an embodiment of the present application provides a vehicle, which is provided with a hydraulic disc brake friction pad wear detection device as described in the first aspect above.

[0023] In summary, the embodiments of the present application provide a disc brake friction pad wear detection device and a vehicle, in which one end of the screw of the hydraulic disc brake cooperates with the piston and the other end is provided with a sliding rheostat. When the friction pad of the disc brake is worn, the gap is self-adjusted to change the position of the piston in the hydraulic brake caliper body, so that the screw follows the piston to produce axial displacement, and the sliding rheostat is used to convert the axial displacement of the screw into an electrical signal, so that the electrical signal reflects the degree of wear of the friction pad in the hydraulic disc brake, thereby realizing accurate detection of the friction pad in the hydraulic disc brake, reducing the complexity of the detection structure, and realizing timely checking of the wear condition of the friction pad during non-braking process, thereby ensuring the driving safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0025] Figure 1 A schematic structural diagram of a hydraulic disc brake assembly provided in an embodiment of the present application;

[0026] Figure 2 A schematic structural diagram of a friction pad detection device for a hydraulic disc brake provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of the exploded structure of the friction pad detection device for a hydraulic disc brake provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram of the structure of the clearance between the screw and the sleeve provided in the embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of the contact surface between the screw, sleeve and piston inside the caliper body provided in an embodiment of the present application;

[0030] Figure 6 A schematic diagram of the structure of a piston provided in an embodiment of the present application;

[0031] Figure 7 A schematic diagram of the structure of the screw provided in the embodiment of the present application;

[0032] Figure 8 This is a schematic structural diagram of the sliding rheostat provided in an embodiment of the present application.

[0033] Description of reference numerals:

[0034] 1-Hydraulic brake caliper body, 2-Sliding rheostat, 3-Screw, 4-First bearing, 5-Conical spring, 6-Second bearing, 7-Sleeve, 8-Third sealing ring, 9-Housing, 10-Brush, 11-Block, 12-Piston, 13-Second sealing ring, 14-First sealing ring, 15-Retaining ring, 16-Resistor, 17-Ball bearing, 18-Conical contact surface between screw and piston, 19-Friction surface between piston and screw sealing ring, 20-Friction surface between screw and sleeve sealing ring, 21-Locating groove, 22-Seal groove, 23-Vent hole, 24-Seal groove, 25-Boss, 26-Oil hole; 27-Thread, 28-Inner hole, 29-Positive wire; 30-Signal wire, 31-Negative wire, 32-Connector, 33-Connecting hole. DETAILED DESCRIPTION

[0035] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0036] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] Understandably, brakes are the key to automotive safety, and brake pads gradually become thinner as they wear out during use. Severely worn pads, if not promptly replaced, can lead to a significant drop in braking torque and an imbalance in braking torque between the left and right wheels. This can cause serious braking issues such as long braking distances and swerving, posing a significant risk to driving safety.

[0038] In order to improve the accurate detection of brake friction pad wear and timely alarm, it is considered that the disc friction pad wear detection device in the existing technology is only applicable to pneumatic disc brakes and cannot be applied to hydraulic disc brakes. In addition, its detection structure has many parts and a complex structure.

[0039] In the embodiment of the present application, in the hydraulic disc brake scenario, Figure 1 As shown, a piston is configured inside the hydraulic brake caliper body. The piston is driven by hydraulic pressure to push the inner brake friction pad close to the brake disc, and the hydraulic brake caliper body is driven by hydraulic pressure, so that the caliper body pushes the outer friction pad close to the brake disc, and finally the inner brake friction pad and the outer friction pad are pressed against the brake disc to achieve braking.

[0040] It is also understood that to maintain good braking efficiency, there can be an optimal gap between the brake shoes, i.e., the inner and outer friction pads, and the brake disc. As the inner and outer brake friction pads wear, the gap between the brake friction pads and the brake disc increases, and the gap can be self-adjusted by the self-adjusting mechanism.

[0041] For example, when the gap between the brake disc and the brake pad increases and needs to be reduced, during the braking process, the piston pushes the brake pad beyond a certain range. This means that the piston's movement exceeds the limit variable of the sealing ring installed between the piston and the hydraulic brake caliper body, and relative sliding occurs between the piston and the sealing ring. This displacement within the brake hydraulic caliper body prevents the relative sliding displacement from returning to its original position when the brake is released as the rectangular ring returns, thereby reducing the gap between the active brake pad and the brake disc. At this point, the piston will remain in its current position, optimizing the gap between the inner brake pad and the brake disc, completing the self-adjustment of the gap and restoring the normal gap state.

[0042] It can be understood that during the aforementioned self-adjustment process, the screw is temporarily suspended by the limiting action of the sleeve, while the piston continues axial movement under the action of hydraulic pressure. At this point, the conical contact surfaces of the screw and piston separate, reducing the screw's rotational resistance while increasing the compression of the conical spring, thereby generating a greater elastic force on the screw. When the circumferential component of the elastic force generated by the compressed conical spring, which is split between the screw and the piston, becomes greater than the screw's rotational resistance, the screw rotates and thus undergoes axial displacement.

[0043] The hydraulic disc brake device in the embodiment of the present application takes into account the displacement of the screw caused by the automatic adjustment mechanism during the self-adjustment of the clearance based on the wear condition of the friction plate. Therefore, during the detection of the wear condition of the friction plate, the brake friction plate wear detection can be combined with the screw displacement of the clearance self-adjusting mechanism, that is, the change in the axial displacement of the screw during the clearance self-adjustment process can be used to reflect the wear change of the friction plate.

[0044] In order to better understand and illustrate the hydraulic disc brake friction pad wear detection device and the automobile provided in the embodiment of the present application, the following is a Figures 1 to 8 Elaborate in detail.

[0045] Figure 1 and Figure 2 As shown, the hydraulic disc brake friction pad wear detection device of the embodiment of the present application specifically includes:

[0046] The hydraulic brake caliper body 1, the piston 12, the screw 3 and the screw sleeve 7, the piston is arranged in the hydraulic brake caliper body of the hydraulic disc brake assembly, the screw sleeve is fixed on the end face of the hydraulic brake caliper body of the caliper, one end of the screw passes through the screw sleeve and cooperates with the piston 12, so that when the hydraulic disc brake performs clearance self-adjustment, the screw and the piston undergo synchronous axial displacement.

[0047] The other end of the screw is provided with a sliding rheostat 2, which is used to convert the axial displacement of the screw into an electrical signal, and the electrical signal is used to indicate the degree of wear of the friction plate in the hydraulic disc brake.

[0048] Specifically, such as Figure 1 and Figure 2 As shown, the hydraulic disc brake in the embodiment of the present application includes a hydraulic brake caliper body 1, a piston 12, a screw 3 and a screw sleeve 7.

[0049] A cavity is provided inside the hydraulic brake caliper body, so that the piston 12 can be arranged in the cavity of the hydraulic brake caliper body, and the left end is in contact with the inner brake friction pad. Under the drive of hydraulic pressure, axial displacement can be generated in the cavity of the hydraulic brake caliper body 1 to push the brake friction pad to press the brake disc to achieve braking.

[0050] Furthermore, to achieve self-adjustment of the clearance and ensure proper fit between the piston 12 and the hydraulic brake caliper body 1, a first sealing ring 14 seals the gap between the piston 12 and the hydraulic brake caliper body 1. It will be appreciated that the maximum axial deformation of this first sealing ring is a predetermined value, typically set to be less than the optimal clearance between the brake disc and the friction pad. During actual braking, when the inner brake friction pad is not rubbing, the hydraulic pressure drives the piston, causing it to move leftward, pushing the inner brake friction pad against the brake disc. This piston movement is less than the maximum deformation. Therefore, when the braking operation is terminated, the piston, under the action of the first sealing ring, returns to its initial position.

[0051] Furthermore, when the brake pads wear to a certain degree, self-adjustment of the clearance is required. During braking, when the hydraulically driven piston moves leftward, pushing the inner brake pad against the brake disc, the gap caused by the wear of the inner brake pad increases. As a result, after the piston reaches the maximum deformation of the first sealing ring, it continues to move leftward. In other words, the piston and the first sealing ring move relative to each other until the inner brake pad presses against the brake disc. At this time, the first sealing ring is still deformed. When braking is completed and the driving force is removed, the piston remains in its current position and moves rightward as the first sealing ring recovers its deformation, maintaining the optimal gap between the friction pad and the brake disc, thus completing the self-adjustment of the clearance.

[0052] For example, in some embodiments, the maximum axial deformation of the first sealing ring may be a third distance c. The specific value of the third distance may be determined according to the actual brake model, such as 0.6 mm. This embodiment of the present application does not impose any limitation on this.

[0053] In the embodiment of the present application, in order to achieve accurate detection of brake pad wear, it can be achieved by detecting the displacement of the piston during the clearance self-adjustment process.

[0054] like Figure 1 and Figure 2 As shown, the cooperation between the piston 12 and the bolt 3 can be utilized so that during the clearance self-adjustment process, the piston 12 and the bolt 3 perform the same displacement, and then the displacement of the bolt is detected to realize the detection of brake friction pad wear.

[0055] Specifically, in the assembly structure of some embodiments, one end of the screw sleeve 7 of the fixing bolt can be fixed on the end face of the hydraulic brake caliper body, so that after one end of the screw rod 3 passes through the screw sleeve 7, it contacts and cooperates with the piston 12, so that when the hydraulic disc brake performs clearance self-adjustment, the screw rod 3 and the piston 12 undergo synchronous axial displacement.

[0056] Optionally, in some embodiments, during the hydraulic disc brake braking and clearance self-adjustment process, the cooperation between the piston 12 and the screw 3 can be achieved by Figure 2 、 Figure 3 and Figure 7 The structure shown is implemented.

[0057] Specifically, such as Figure 2 As shown, the end of the screw rod near the piston 12 can be configured as a conical structure, and a boss 25 can be formed at one end of the screw rod, that is, the end of the screw rod 3 that cooperates with the piston 12 can be configured as a conical boss structure. Figure 2 As shown, the first bearing 4 is arranged at the end of the screw rod 3 close to the piston 12, that is, at the position close to the right side of the boss 25, and the second bearing 6 is arranged at the end of the piston close to the screw sleeve, so that in the axial direction, the first bearing 4 is closer to the brake friction plate than the second bearing 6, that is, Figure 2 The first bearing 4 arranged on the screw 3 is located on the left side of the second bearing 6 arranged on the screw sleeve 7.

[0058] Furthermore, in order to achieve the self-adjustment of the clearance after the brake friction pad is worn, the screw rod can move with the piston to generate axial displacement after the clearance is self-adjusted, and a conical spring 5 can be arranged between the first bearing 4 and the second bearing 6.

[0059] like Figure 2As shown, in order to make the piston 12 and the screw 3 better cooperate with the conical spring 5 configured above, to ensure that the screw 3 can perform synchronous axial displacement as the piston moves, and to ensure that during normal braking, the axial displacement of the screw is avoided to cause interference with the wear detection device, the conical structure of the screw 3 can be used to set the contact surface between the inside of the piston 12 and the screw 3 as an inclined surface to increase the friction between the piston and the screw.

[0060] Optionally, in order to form a sealed environment in the brake to prevent brake fluid leakage, Figure 7 As shown, a screw sealing groove 24 may be provided at the end of the screw 3 close to the piston, and a second sealing ring 13 may be provided in the screw sealing groove 24 to achieve sealed contact between the front end of the screw and the piston.

[0061] Optional, such as Figure 2 and Figure 7 As shown, in order to achieve the cooperation between the screw 3 and the screw sleeve 7, an external thread 27 can be provided on the middle part of the screw 3 and an internal thread can be provided on the inner wall of the screw sleeve 7.

[0062] Furthermore, in order to better form a sealed environment inside the brake and prevent brake fluid leakage, a third sealing ring 8 fixed on the screw sleeve 7 can be used to seal the two.

[0063] It is understandable that Figure 5 As shown, after the above-mentioned structure of the embodiment of the present application is assembled, friction surfaces can be formed between the piston 12, the screw 3 and the screw sleeve 7 inside the hydraulic brake caliper body 1, such as the friction surface 18 where the conical boss 25 of the screw 3 contacts the inclined surface inside the piston 12, the contact friction surface 19 between the second sealing ring 13 and the piston 12, and the contact friction surface 20 between the third sealing ring 8 and the screw 3.

[0064] It is understandable that Figure 2 As shown, since the thread of the screw is set as an inclined structure, after the piston and the contact surface 18 of the screw are separated, the screw can smoothly follow the piston to move axially to the left under the action of the conical spring.

[0065] Further, if Figure 4 As shown, in order to ensure smooth cooperation between the screw 3 and the screw sleeve 7, a certain cooperation gap, ie, a second distance b, can be configured between the internal thread on the screw sleeve 7 and the external thread 27 on the screw 3.

[0066] Optional, such as Figure 6 As shown, the end surface of the piston 12 that contacts the brake friction plate has a positioning groove 21 to prevent the piston 12 from rotating.

[0067] In addition, a sealing groove 22 is provided on the circumferential surface of the piston 12 to achieve sealing between the piston 12 and the hydraulic brake caliper body 1 .

[0068] Optionally, in some embodiments, in order to eliminate negative pressure in the cavity of the hydraulic brake caliper body 1, a vent hole 23 can be provided at the sealing groove 22 of the piston 12. Thus, when the piston moves in the cavity of the hydraulic brake caliper body 1, the negative pressure generated can be promptly eliminated through the vent hole 23.

[0069] Furthermore, in order to facilitate the replacement of worn brake friction pads, a retaining ring 15 can be provided on the piston 12 near the position of the tapered structure. Thus, when the screw rod 3 is retracted during the replacement of the brake friction pads, the retaining ring 15 can be used to retract the piston 12 together.

[0070] It can be understood that, as shown in FIG4 , the axial clearance between the retaining ring 15 and the boss 25 of the screw 3 can be set to a fourth distance d.

[0071] Optional, such as Figure 7 As shown, in the embodiment of the present application, in order to ensure smooth cooperation between the screw and the piston, a screw oil hole 26 can also be configured on the conical boss 25 of the screw.

[0072] It is understandable that Figure 4 As shown, the disc brake friction pad wear detection device recorded in the above embodiment, if the first distance a is the design gap between the brake disc and the friction pad, or can be understood as the design gap between the brake disc and the friction pad and the sum of the deformation of the friction pad and the caliper body, the second distance b is the thread fitting clearance of the external thread 27 of the screw 3 and the internal thread of the sleeve 7, the third distance c is the limit deformation of the first sealing ring 14 after assembly, the fourth distance d is the assembly clearance of the screw 3 and the retaining ring 15, the fifth distance e is the length of the screw 3 extending out of the right side of the sleeve 7, the sixth distance f is the thread fitting length of the screw 3 and the sleeve 7, and the seventh distance g is the limit wear of the brake disc-friction pad.

[0073] Then the fit clearance size between the above distances satisfies:

[0074] a≤b≤c≤d<g<e<f.

[0075] It can be understood that the purpose of e<f is to ensure that the screw 3 and the screw sleeve 7 must maintain thread engagement and not fall off when the screw 3 is displaced in the full stroke; the purpose of g<e is to ensure that the self-adjusting mechanism of the brake disc and friction plate can function normally.

[0076] It is also understood that the specific values ​​of the above distances can be determined according to the actual brake model. For example, in some embodiments, the third distance can be set to 1.6 mm, the fourth distance can be set to 2 mm, and the seventh distance can be set to more than ten millimeters. This embodiment of the present application is not limited to this.

[0077] Furthermore, in an embodiment of the present application, in order to accurately detect the wear condition of the brake friction pad, that is, accurately detect the axial displacement of the screw, a sliding rheostat 2 can be configured at the other end of the screw 3, so that the axial displacement of the screw 3 can be converted into an electrical signal by using the sliding rheostat.

[0078] That is, since the axial displacement generated by the screw is related to the wear of the brake friction pad, a sliding rheostat 2 can be arranged at the other end of the screw so that the output voltage of the sliding rheostat 2 is related to the axial displacement of the screw, that is, the axial displacement of the screw is converted into an electrical signal through the sliding rheostat to indicate the degree of wear of the friction pad in the hydraulic disc brake.

[0079] Optional, such as Figure 2 and Figure 3 As shown, the sliding rheostat 2 may include a housing 9, a brush 10, and a resistor 11. The housing may be disposed on the end surface of the screw sleeve 7 away from the piston 12. The resistor is fixed to the side wall of the housing 9, and the brush 10 is disposed on the screw 3. The brush 10 moves with the screw 3 and slides into contact with the resistor 11.

[0080] Optionally, in some embodiments, in order to improve the connection stability between the brush 10 and the screw 3 of the sliding rheostat 2, the brush 10 and the screw 3 can be fixed by a ball bearing 17. This can prevent the brush from rotating circumferentially during the axial displacement generated by the rotation of the screw 3.

[0081] And, as Figure 7-8 As shown, in order to achieve the fixation of the sliding rheostat 2, a connecting hole 33 can be configured on the end face of the housing 9 of the sliding rheostat 2 away from the screw sleeve. Correspondingly, a hexagonal hole 28 can be configured on the end face of the screw rod 3, so that the screw rod 3 and the sliding rheostat can be stably connected by bolts using the connecting hole 33 and the hexagonal hole 28.

[0082] Optional, such as Figure 2 As shown, in order to prevent muddy water from entering the interior of the housing, a plug 11 can be provided on the end face of the housing 9 away from the screw sleeve, and the plug 11 can be interference fit with the connecting hole 33 of the sliding rheostat housing 9.

[0083] Further, if Figure 8 As shown, the housing is provided with a connector 32, which includes a positive line 29, a signal line 30 and a negative line 31. The signal line 30 is connected to the brush 10. The positive line and the negative line are connected to the two ends of the resistor of the sliding rheostat.

[0084] It can be understood that in actual operation of the hydraulic disc brake friction pad detection device in the above embodiment, when assembly is completed and the brake friction pad is not worn, the sliding rheostat outputs an initial voltage value, and the initial voltage value is displayed on the vehicle's dashboard for the driver to view in real time.

[0085] Specifically, when the friction pads in a hydraulic disc brake are unworn, that is, the gap between the brake disc and the pads is at the optimal gap a, then when braking occurs, the piston displacement equals a. At this point, driven by the hydraulic pressure, the piston pushes the brake pads leftward, driving the second bearing 6 to move left and right, compressing the brake disc. This causes the screw 3, under the force of the second bearing 6, to move synchronously with the piston 12 without rotating, resulting in a displacement of a. During this process, the first sealing ring 14 deforms, but does not exceed the maximum deformation. When braking is complete and the hydraulic driving force is removed, the first sealing ring 14 recovers its deformation, causing the piston and the screw to return to their initial positions.

[0086] Similarly, when the brake pads wear to a certain degree, the gap between the brake disc and the pads becomes greater than a and less than b. At this point, during braking, the screw 3, under the force of the second bearing 6, also moves synchronously with the piston 12 and does not rotate. When braking is complete and the hydraulic driving force is removed, the piston returns to its initial position, causing the screw to return to its initial position.

[0087] It can be understood that during the above process, that is, during the braking process of the vehicle, due to a slight axial displacement change of the screw, the output voltage may fluctuate, and after the braking is completed, the output voltage will still return to the initial value.

[0088] Furthermore, when the brake pads wear to a certain extent, the clearance between the brake disc and the pads increases from b to c. During braking, the displacement of piston 12 increases from b to c. That is, during braking, the piston's leftward movement keeps the deformation of the first sealing ring within its maximum deformation range. The threads of the screw and the sleeve abut, preventing the screw from moving in this position. As the piston continues to move left, the boss 25 of screw 3 separates from the conical surface of piston 12, and friction surface 18 disappears. The first bearing remains stationary, while the second bearing moves leftward. The conical spring compresses, generating a rotational torque on the screw. However, this torque is less than the resistance of friction surfaces 19 and 20. At this point, screw 3 still does not rotate. When braking is complete and the hydraulic driving force is removed, the first sealing ring 14 recovers its deformation, returning the piston and the screw to their initial positions.

[0089] It is understandable that in the above process, due to the slight axial reciprocating displacement of the screw, the output voltage may also fluctuate, and after the braking is completed, the output voltage will still return to the initial value.

[0090] Furthermore, when the friction pad is severely worn, that is, when the gap between the brake disc and the brake pad is greater than c, self-adjustment of the gap can be performed during the braking process. After braking, the displacement of the hydraulically driven piston exceeds c, exceeding the maximum deformation of the first sealing ring, causing slippage between the piston and the first sealing ring, and the first sealing ring is in a state of maximum deformation. At this point, the conical spring 5 is further compressed, and the screw 3 generates a greater rotational torque, which is greater than the resistance of friction surfaces 19 and 20. At this point, due to the reduced rotational resistance and the sufficient rotational force generated by the compressed conical spring, the screw rotates, following the piston's leftward displacement, until the screw 3 and the conical surface of the piston 12 are again in contact.

[0091] At this point, after braking is complete (i.e., the hydraulic driving force of the piston is removed), the piston, under the restoring force of the first sealing ring, is positioned at the optimal clearance a, completing the clearance self-adjustment. During the braking and clearance self-adjustment process, the leftward displacement of the screw may cause a change in the output voltage. Specifically, after braking is complete, the output voltage will vary to a certain extent. In practice, this change can be displayed on an instrument panel, or the output voltage value after the change can be directly displayed for the driver to observe in real time.

[0092] It can be understood that the difference between the changed output voltage value and the initial voltage value indicates the axial displacement of the screw, that is, the displacement of the piston during the clearance self-adjustment process, that is, the wear of the brake friction pad.

[0093] It is also understood that in some embodiments, the output voltage of the sliding rheostat is mapped to the wear of the brake friction pad. Specifically, a specific output voltage corresponds to a percentage of wear of the brake friction pad. When the corresponding percentage reaches a certain value, it indicates that the brake friction pad needs to be replaced. Specifically, an alarm can be displayed on the instrument panel, such as an indicator light.

[0094] If the thickness of the brake friction pad is calculated to be 2 mm through the output voltage of the potentiometric sensor and the corresponding wear percentage, it means that the brake friction pad needs to be replaced.

[0095] When the friction plate needs to be replaced, the screw is unscrewed in the opposite direction, and the screw drives the piston back through the retaining ring, making it easier to replace the new friction plate.

[0096] It can also be understood that due to the different vehicles and specific models of brake shoes, the wear amount of the brake friction pad corresponding to the output voltage is also different, and can actually be determined based on the actual product.

[0097] On the other hand, an embodiment of the present application further provides a vehicle, in which a braking mechanism may include a hydraulic disc brake, and the hydraulic disc brake may include a friction plate wear detection device as described in the above embodiment.

[0098] In summary, the embodiments of the present application provide a disc brake friction pad wear detection device and a vehicle. A sliding rheostat is configured at the other end of the screw of the hydraulic disc brake. When the friction pad of the disc brake is worn, the output voltage of the sliding rheostat changes when the screw is used for axial self-adjustment. The sliding rheostat can then be used to convert the axial displacement of the screw into an electrical signal, so that the electrical signal reflects the degree of wear of the friction pad in the hydraulic disc brake, thereby achieving accurate detection of the friction pad in the hydraulic disc brake, reducing the complexity of the detection structure, and ensuring the driving safety of the vehicle.

[0099] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the scope of the present invention. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A disc brake friction pad wear detection device, characterized in that: include: A hydraulic brake caliper body, a piston, a screw and a threaded sleeve. The piston is arranged in the hydraulic brake caliper body, and the threaded sleeve is fixed on the end surface of the hydraulic brake caliper body. One end of the screw passes through the threaded sleeve and cooperates with the piston, so that when the hydraulic disc brake performs clearance self-adjustment, the screw and the piston undergo synchronous axial displacement. The other end of the screw is provided with a sliding rheostat, which is used to convert the axial displacement of the screw into an electrical signal, and the electrical signal is used to indicate the degree of wear of the friction plate in the hydraulic disc brake; The screw is provided with a first bearing at one end close to the piston, and a second bearing is provided on the inner wall of the piston. The first bearing and the second bearing are coaxially arranged, and the first bearing is closer to the end where the screw and the piston are engaged than the second bearing. A conical spring is provided between the first bearing and the second bearing. A first sealing ring is arranged between the piston and the hydraulic brake caliper body. During the braking process, the first sealing ring can be deformed. After the braking operation is terminated, the piston returns to its initial position under the action of the first sealing ring. A second sealing ring is arranged between the screw and the piston, and a third sealing ring is arranged between the screw and the screw sleeve. The end of the screw rod close to the piston is configured as a conical structure, the conical structure of the screw rod is configured with a boss, and the inner wall of the piston close to the conical structure is provided with a circumferential retaining ring, and the retaining ring is located between the boss and the first bearing; The contact end surface of the piston and the friction plate is provided with a positioning groove, the outer circumferential surface of the piston is provided with a sealing groove, and the sealing groove is provided with a vent hole.

2. The disc brake friction pad wear detection device according to claim 1, characterized in that: One end of the screw rod that cooperates with the piston is provided with a sealing groove, and the second sealing ring is arranged in the sealing groove.

3. The disc brake friction pad wear detection device according to claim 1, characterized in that: The middle portion of the screw is provided with a thread that cooperates with the screw sleeve.

4. The disc brake friction pad wear detection device according to claim 3, characterized in that: The boss is provided with an oil hole.

5. The disc brake friction pad wear detection device according to any one of claims 1 to 4, characterized in that: In a hydraulic disc brake, the gap between the brake disc and the friction plate is a first distance, the thread fit clearance between the screw and the sleeve is a second distance, the limit deformation of the first sealing ring after assembly is a third distance, the assembly clearance between the screw and the retaining ring is a fourth distance, the length of the screw extending from the sleeve is a fifth distance, the thread fit length between the screw and the sleeve is a sixth distance, and the limit wear between the brake disc and the friction plate is a seventh distance. The fitting clearance of the hydraulic disc brake satisfies the following conditions: The first distance ≤ the second distance ≤ the third distance ≤ the fourth distance < the seventh distance < the fifth distance < the sixth distance.

6. The disc brake friction pad wear detection device according to any one of claims 1 to 4, characterized in that: The sliding rheostat includes a housing, a resistor sheet and a brush. The housing is arranged on the end surface of the screw sleeve away from the piston, the resistor is fixed in the side wall of the housing, and the brush is arranged on the screw. The brush moves with the screw and comes into sliding contact with the resistor.

7. The disc brake friction pad wear detection device according to claim 6, characterized in that: A connector is disposed on the housing. The connector includes a positive line, a signal line, and a negative line. The signal line is connected to the brush, and the positive line and the negative line are connected to both ends of the resistor.

8. The disc brake friction pad wear detection device according to claim 6, characterized in that: A connecting hole is arranged on the end surface of the shell away from the screw sleeve, and the other end of the screw rod is arranged with a hexagonal hole for matching with the connecting hole.

9. The disc brake friction pad wear detection device according to claim 8, characterized in that: A plug that matches the connecting hole is arranged on the end surface of the shell away from the screw sleeve.

10. A vehicle, characterized in that: The invention comprises a disc brake friction pad wear detection device as described in any one of claims 1 to 9.

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