Disc brake

Abstract

The utility model relates to the technical field of vehicle braking, and discloses a disc brake. The disc brake comprises a caliper body, a sliding pin and a sealing assembly. A mounting hole is formed in the caliper body in the axial direction of the caliper body. The sliding pin is assembled in the mounting hole and used for being connected with the bracket in a fastened mode. The sealing assembly comprises a protective sleeve and an elastic sealing sleeve; the elastic sealing sleeve sleeves the outer side surface of one end, close to the bracket, of the sliding pin, is hermetically assembled with the sliding pin and is in sliding fit with the sliding pin in the axial direction of the caliper body; the protective sleeve is arranged on the outer side face of the elastic sealing sleeve in a sleeving mode and connected to the elastic sealing sleeve and the clamp body. According to the utility model, the elastic sealing sleeve is arranged to realize soft sealing of the joint of the sliding pin and the clamp body; according to the disc brake, the protective sleeve is arranged, hard sealing of the connecting position of the sliding pin and the caliper body can be achieved, the function of protecting the elastic sealing sleeve is achieved, and the defects that in the prior art, a disc brake is poor in splash-proof capacity and short in service life can be overcome through the mode that soft sealing and hard sealing are combined.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle braking, in particular to a disc brake. Background Art

[0002] Disc brakes are important actuators in the automobile braking system. They are usually connected to the spring brake chamber on the axle and connected to the braking system through air pipes. When the driver steps on the brake pedal, the push disc of the spring brake chamber is pushed through the control of various components of the braking system, and the force is transmitted to the thrust arm on the disc brake, which drives the disc brake friction pad to clamp the brake disc, generating braking force to slow down or stop the vehicle. When the brake pedal is released, the return mechanism inside the disc brake returns the brake to its initial state, releasing the braking force.

[0003] However, the splash-proof capability of the existing disc brake is weakened during use, which seriously affects the service life of the disc brake and affects the promotion of the disc brake. Utility Model Content

[0004] The utility model provides a disc brake, which is used to solve the defects of the disc brake in the prior art, namely, weak anti-splashing ability and short service life.

[0005] The utility model provides a disc brake, comprising:

[0006] A caliper body, wherein a mounting hole is formed in the caliper body along the axial direction of the caliper body;

[0007] A sliding pin, mounted in the mounting hole and used for being fastened to the bracket;

[0008] The sealing assembly includes a protective sleeve and an elastic sealing sleeve; the elastic sealing sleeve is sleeved on the outer side surface of the sliding pin close to one end of the bracket, the elastic sealing sleeve is seal-assembled with the sliding pin and slides along the axial direction of the caliper body; the protective sleeve is sleeved on the outer side surface of the elastic sealing sleeve, and the protective sleeve is connected to the elastic sealing sleeve and the caliper body.

[0009] According to the disc brake provided by the utility model, the protective sleeve includes a metal sleeve, and the elastic sealing sleeve includes a silicone sealing sleeve or a rubber sealing sleeve.

[0010] According to the disc brake provided by the utility model, a first limiting platform is formed on the outer side surface of the elastic sealing sleeve, and a first limiting protrusion is formed on the inner side surface of the protective sleeve, and the first limiting protrusion cooperates with the first limiting platform along the axial direction.

[0011] According to the disc brake provided by the utility model, the protective sleeve includes:

[0012] a first sleeve section, wherein the diameter of the first sleeve section gradually decreases in a direction approaching the bracket;

[0013] a second casing section, wherein one end of the second casing section close to the bracket is coaxially spliced ​​with the first casing section, and the diameter of the second casing section is greater than the diameter of the first casing section;

[0014] The third sleeve segment, one end of the second sleeve segment away from the bracket is coaxially spliced ​​with the third sleeve segment, the diameter of the third sleeve segment is larger than the diameter of the second sleeve segment, so that the first limiting protrusion is formed at the splicing of the second sleeve segment and the third sleeve segment.

[0015] The disc brake provided by the utility model also includes:

[0016] A plastic ring sleeve is sleeved on the outer side surface of one end of the sliding pin close to the bracket, the plastic ring sleeve is axially limited by the sliding pin and axially slides with the caliper body; the elastic sealing sleeve is sleeved on the outer side surface of the plastic ring sleeve, the elastic sealing sleeve is sealed and assembled with the plastic ring sleeve, and slides axially with the caliper body.

[0017] According to the disc brake provided by the utility model, a second limiting platform is formed on the outer side surface of the sliding pin, and the end of the plastic ring sleeve away from the bracket is axially limitedly matched with the second limiting platform.

[0018] According to the disc brake provided by the utility model, along the axial direction of the plastic ring sleeve, the outer side surface of the plastic ring sleeve is formed with a first limiting portion and a second limiting portion; the first limiting portion is located between the bracket and the second limiting portion; the first limiting portion abuts or separates from the end surface of the protective sleeve close to the bracket, and the second limiting portion abuts or separates from the lip of the elastic sealing sleeve.

[0019] According to the disc brake provided by the utility model, when the first limiting portion abuts against the end face of the protective sleeve close to the bracket, a first distance L1 between the end face of the protective sleeve facing the bracket and the bracket is 4~6mm, and a second distance L2 between the lip of the elastic sealing sleeve and the second limiting portion is 20~23mm.

[0020] According to the disc brake provided by the utility model, the interference between the lip of the elastic sealing sleeve and the plastic ring sleeve is 0.35-0.5 mm.

[0021] According to the disc brake provided by the utility model, a first gap is formed between the inner side surface of one end of the protective sleeve close to the bracket and the outer side surface of the plastic ring sleeve, and the radial dimension of the first gap is 0.2-0.5 mm.

[0022] The disc brake provided by the utility model is provided with a sealing assembly including a protective sleeve and an elastic sealing sleeve. The elastic sealing sleeve can realize soft sealing of the connection between the sliding pin and the caliper body, thereby playing a waterproof role. On the one hand, the protective sleeve can connect the elastic sealing sleeve to the caliper body, so that the elastic sealing sleeve can slide with the caliper body relative to the sliding pin; on the other hand, it can realize hard sealing of the connection between the sliding pin and the caliper body, and at the same time play a role in protecting the elastic sealing sleeve, thereby preventing the elastic sealing component from being damaged by hard debris such as stones when the vehicle is driving. In other words, this embodiment uses a combination of soft sealing and hard sealing to seal the connection between the sliding pin and the caliper body, which can greatly improve the sealing performance of the disc brake, enhance the wading ability of the disc brake, improve the reliability of the seal, and increase the service life of the disc brake, thereby solving the defects of the disc brake in the prior art, such as weak splash-proof ability and short service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is a three-dimensional structural schematic diagram of the disc brake provided by the utility model.

[0025] Figure 2 The utility model is a cross-sectional structural schematic diagram of a disc brake.

[0026] Figure 3 This is one of the structural schematic diagrams of the protective cover of the disc brake provided by the utility model.

[0027] Figure 4 This is the second structural schematic diagram of the protective cover of the disc brake provided by the utility model.

[0028] Figure 5 The utility model is a schematic structural diagram of an elastic sealing sleeve of a disc brake.

[0029] Figure 6 The utility model is a structural schematic diagram of a plastic ring sleeve of a disc brake provided by the utility model.

[0030] Reference numerals:

[0031] 100, clamp body; 200, bracket; 300, slide pin;

[0032] 400, sealing assembly; 410, protective sleeve; 420, elastic sealing sleeve; 411, first sleeve section; 412, second sleeve section; 413, third sleeve section; 414, first limiting protrusion; 421, first limiting platform;

[0033] 500, plastic ring sleeve; 510, second limiting portion;

[0034] 600, bushing; 700, bolt; 800, sliding pin cover. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] In the description of the embodiments of the present utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present utility model. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0038] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model embodiment. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0040] The current disc brakes have poor wading capabilities, especially the sliding pins, which are difficult to seal. While ensuring the normal sliding of the caliper, the sealing of the sliding pins must also be ensured. It is easy for the sliding pin protection cover to fail, causing water to enter the sliding pins of the disc brakes, affecting the service life of the disc brakes. The current industry technology is to improve the sealing performance of the sliding pins by increasing the strength of the sliding pin protection cover and optimizing the installation method of the sliding pin protection cover. However, the current sealing method is still to soft-seal the sliding pins with elastomers such as rubber, and this soft sealing method has low reliability. In harsh environments, such as roads with a large number of crosses, the soft seal structure is easily damaged, thereby reducing the service life of the disc brakes.

[0041] like Figure 1 and Figure 2As shown, a specific embodiment of the utility model provides a disc brake. The disc brake includes a caliper body 100, a sliding pin 300 and a sealing assembly 400; along the axial direction of the caliper body 100, the caliper body 100 is provided with a mounting hole. The sliding pin 300 is assembled in the mounting hole and is used to be fastened to the bracket 200. The sealing assembly 400 includes a protective sleeve 410 and an elastic sealing sleeve 420; the elastic sealing sleeve 420 is sleeved on the outer side surface of the sliding pin 300 close to one end of the bracket 200, the elastic sealing sleeve 420 is sealed and assembled with the sliding pin 300 and slides along the axial direction of the caliper body 100; the protective sleeve 410 is sleeved on the outer side surface of the elastic sealing sleeve 420, and the protective sleeve 410 is connected to the elastic sealing sleeve 420 and the caliper body 100.

[0042] In this embodiment, by providing a sealing assembly 400 including a protective sleeve 410 and an elastic sealing sleeve 420, the elastic sealing sleeve 420 can achieve a soft seal at the connection between the sliding pin 300 and the caliper body 100, and play a waterproof role; the protective sleeve 410 can connect the elastic sealing sleeve 420 with the caliper body 100 on the one hand, so that the elastic sealing sleeve 420 can slide with the caliper body 100 relative to the sliding pin 300; on the other hand, it can achieve a hard seal at the connection between the sliding pin 300 and the caliper body 400, and at the same time play a role in protecting the elastic sealing sleeve 420, preventing hard debris such as stones from damaging the elastic seal when the vehicle is driving. That is to say, this embodiment uses a combination of soft sealing and hard sealing to seal the connection between the sliding pin 300 and the caliper body 400, which can greatly improve the sealing performance of the disc brake, enhance the wading ability of the disc brake, improve the reliability of the seal, and increase the service life of the disc brake, solving the defects of weak splash-proof ability and short service life of the disc brake in the prior art.

[0043] like Figure 2 As shown, further, the disc brake further includes a bushing 600 , which is sleeved on the outer side of the sliding pin 300 , and the bushing 600 is connected to the caliper body 100 , and can slide relative to the sliding pin 300 along with the caliper body 100 .

[0044] like Figure 2 As shown, further, the sliding pin 300 is connected to the bracket 200 via a bolt 700 .

[0045] like Figure 1 and Figure 2 As shown, further, a sliding pin cover 800 is provided at one end of the sliding pin 300 away from the bracket 200 , and the sliding pin cover 800 is connected to the caliper body 100 and can move with the caliper body 100 relative to the sliding pin 300 .

[0046] In some embodiments, the protective sleeve 410 includes a metal sleeve, and the elastic sealing sleeve 420 includes a silicone sealing sleeve or a rubber sealing sleeve. The metal sleeve is conveniently connected to the pliers body 100, for example, the metal sleeve can be connected to the pliers body 100 by welding. The silicone sealing sleeve or the rubber sealing sleeve can be elastically deformed, which can achieve a better sealing effect.

[0047] like Figure 2 and Figure 5 As shown, in some embodiments, a first limiting platform 421 is formed on the outer side of the elastic sealing sleeve 420. Figure 2 and Figure 4 As shown, the inner side of the protective sleeve 410 is formed with a first limiting protrusion 414, and the first limiting protrusion 414 is axially limited with the first limiting platform 421. The elastic sealing sleeve 420 is connected to the protective sleeve 410 by axially limiting, ensuring that the protective sleeve 410 can drive the elastic sealing sleeve 420 to slide relative to the sliding pin 300 in the axial direction.

[0048] like Figure 3 and Figure 4 As shown, in some embodiments, the protective sleeve 410 includes a first sleeve section 411, a second sleeve section 412, and a third sleeve section 413. The diameter of the first sleeve section 411 gradually decreases in the direction close to the bracket 200. The end of the second sleeve section 412 close to the bracket 200 is coaxially spliced ​​with the first sleeve section 411, and the diameter of the second sleeve section 412 is greater than the diameter of the first sleeve section 411. The end of the second sleeve section 412 away from the bracket 200 is coaxially spliced ​​with the third sleeve section 413, and the diameter of the third sleeve section 413 is greater than the diameter of the second sleeve section 412, so that the splicing of the second sleeve section 412 and the third sleeve section 413 forms a first limiting protrusion 414.

[0049] In this embodiment, by designing the protective sleeve 410 as a pipe with different diameters, on the one hand, a first limiting protrusion 414 can be formed to facilitate axial limiting cooperation with the elastic sealing sleeve 420; on the other hand, the elastic sealing sleeve 420 can be further squeezed to improve the sealing effect.

[0050] Specifically, the protective sleeve 410 completely wraps the elastic sealing sleeve 420 to achieve all-round protection for the elastic sealing sleeve 420 and prevent the elastic sealing sleeve 420 from being damaged by hard impurities such as stones.

[0051] It can be understood that the shape of the elastic sealing sleeve 420 matches the shape of the protective sleeve 410 to ensure that the two can be better sealed and assembled.

[0052] like Figure 5 As shown, further, the inner side surface of the elastic sealing sleeve 420 close to one end of the bracket 200 has a plurality of lips, and the plurality of lips are arranged at intervals, which can greatly improve the waterproof capability.

[0053] Preferably, the number of lips is 3 to 5.

[0054] like Figure 2 As shown, in some embodiments, the disc brake further comprises a plastic ring sleeve 500. The plastic ring sleeve 500 is sleeved on the outer side surface of the end of the sliding pin 300 close to the bracket 200, the plastic ring sleeve 500 and the sliding pin 300 are axially limited, and the caliper body 100 is axially slidably matched; the elastic sealing sleeve 420 is sleeved on the outer side surface of the plastic ring sleeve 500, the elastic sealing sleeve 420 and the plastic ring sleeve 500 are sealed and axially slidably matched.

[0055] In this embodiment, by sleeved a plastic ring sleeve 500 on the outer side of the sliding pin 300 and sleeved an elastic sealing sleeve 420 on the outer side of the plastic ring sleeve 500, the friction resistance encountered by the elastic sealing sleeve 420 during the sliding process can be reduced, the protection capability of the sliding pin 300 can be improved, and the sealing performance can be ensured.

[0056] Preferably, the plastic ring sleeve 500 and the sliding pin 300 are interference fit.

[0057] Furthermore, the plastic ring sleeve 500 includes a polytetrafluoroethylene ring sleeve, and the Shore hardness at room temperature is greater than 80 MPa. Compared with the metal ring sleeve, the polytetrafluoroethylene ring sleeve can ensure high protection capability and better sealing performance under the premise of ensuring a small sliding friction coefficient.

[0058] In some embodiments, a second limiting platform is formed on the outer side of the sliding pin 300, and the end of the plastic ring 500 away from the bracket 200 is axially limited with the second limiting platform, which is convenient for processing and has a simple structure. When the caliper body 100 moves axially, the caliper body 100 can drive the protective sleeve 410, and the protective sleeve 410 drives the elastic sealing sleeve 420 to move axially. At this time, the end face of the plastic ring 500 abuts against the second limiting platform, so the plastic ring 500 will not move with the elastic sealing sleeve 420.

[0059] Furthermore, the end surface of the plastic sleeve 500 close to the bracket 200 abuts against the bracket 200. That is, the bracket 200 and the second limiting platform sandwich the plastic sleeve 500, the bracket 200 limits the plastic sleeve 500 to the left, and the second limiting platform limits the plastic sleeve 500 to the right, and the bracket 200 and the second limiting platform cooperate with each other to prevent the plastic sleeve 500 from sliding relative to the sliding pin 300.

[0060] like Figure 2 and Figure 6As shown, in some embodiments, along the axial direction of the plastic ring sleeve 500, the outer side surface of the plastic ring sleeve 500 is formed with a first limiting portion (not shown in the figure) and a second limiting portion 510; the first limiting portion is located between the bracket 200 and the second limiting portion 510; the first limiting portion abuts or separates from the end surface of the protective sleeve 410 close to the bracket 200, and the second limiting portion 510 abuts or separates from the lip of the elastic sealing sleeve 420.

[0061] In this embodiment, when the first limiting portion abuts against the end surface of the protective sleeve 410 close to the bracket 200, this position is the limit position of the caliper body 100 moving to the left. When the second limiting portion 510 abuts against the lip of the elastic sealing sleeve 420, this position is the limit position of the caliper body 100 moving to the right. Therefore, by providing the first limiting portion and the second limiting portion 510, the displacement of the caliper body 100 along the axial movement can be limited. The second limiting portion 510 can also prevent the lip of the elastic sealing sleeve 420 from being excessively fitted with the plastic ring sleeve 500 to affect the movement of the disc brake.

[0062] like Figure 2 As shown, further, when the first limiting portion abuts against the end surface of the protective sleeve 410 close to the bracket 200, the first distance L1 between the end surface of the protective sleeve 410 facing the bracket 200 and the bracket 200 is 4-6 mm, and the second distance L2 between the lip of the elastic sealing sleeve 420 and the second limiting portion 510 is 20-23 mm. The normal sliding of the disc brake can be ensured.

[0063] Furthermore, the interference between the lip of the elastic sealing sleeve 420 and the plastic ring sleeve 500 is 0.35-0.5 mm, which can play a role of waterproofing and dustproofing while ensuring reasonable sliding resistance of the pliers body 100.

[0064] Furthermore, a first gap is formed between the inner side surface of the end of the protective sleeve 410 close to the bracket 200 and the outer side surface of the plastic ring sleeve 500, and the radial dimension of the first gap is 0.2-0.5 mm. This can prevent foreign matter from entering the plastic ring sleeve 500 without affecting the sliding of the caliper body 100, and provide a more comprehensive protection for the elastic sealing sleeve 420.

[0065] by Figure 1 and Figure 2 Taking the disc brake as an example, the working process of the disc brake of the utility model includes:

[0066] The protective sleeve 410, the elastic sealing sleeve 420, the bushing 600 and the sliding pin cover 800 move leftward together with the caliper body 100. When the left end surface of the protective sleeve 410 abuts against the first limiting portion (not shown in the figure) on the plastic ring sleeve 500, the caliper body 100 stops moving leftward.

[0067] Subsequently, the protective sleeve 410, the elastic sealing sleeve 420, the bushing 600 and the sliding pin cover 800 move rightward together with the caliper body 100. When the lip of the elastic sealing sleeve 420 abuts against the second limiting portion 510 on the plastic ring sleeve 500, the caliper body 100 stops moving rightward.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A disc brake, characterized in that: include: A pliers body (100), wherein the pliers body (100) is provided with a mounting hole along the axial direction of the pliers body (100); A sliding pin (300) is mounted in the mounting hole and is used to be fixedly connected to the bracket (200); The sealing assembly (400) comprises a protective sleeve (410) and an elastic sealing sleeve (420); the elastic sealing sleeve (420) is sleeved on the outer side surface of the sliding pin (300) close to one end of the bracket (200), the elastic sealing sleeve (420) and the sliding pin (300) are sealingly assembled and slidably matched along the axial direction of the caliper body (100); the protective sleeve (410) is sleeved on the outer side surface of the elastic sealing sleeve (420), and the protective sleeve (410) is connected to the elastic sealing sleeve (420) and the caliper body (100).

2. The disc brake according to claim 1, characterized in that The protective sleeve (410) comprises a metal sleeve, and the elastic sealing sleeve (420) comprises a silicone sealing sleeve or a rubber sealing sleeve.

3. The disc brake according to claim 1, characterized in that The outer side surface of the elastic sealing sleeve (420) is formed with a first limiting platform (421), and the inner side surface of the protective sleeve (410) is formed with a first limiting protrusion (414), and the first limiting protrusion (414) cooperates with the first limiting platform (421) in axial limiting manner.

4. The disc brake according to claim 3, characterized in that The protective sleeve (410) comprises: A first sleeve section (411), wherein the diameter of the first sleeve section (411) gradually decreases in a direction approaching the bracket (200); a second sleeve section (412), wherein one end of the second sleeve section (412) close to the bracket (200) is coaxially spliced ​​with the first sleeve section (411), and the diameter of the second sleeve section (412) is greater than the diameter of the first sleeve section (411); A third sleeve section (413), one end of the second sleeve section (412) away from the bracket (200) is coaxially spliced ​​with the third sleeve section (413), the diameter of the third sleeve section (413) is larger than the diameter of the second sleeve section (412), so that the first limiting protrusion (414) is formed at the splicing point of the second sleeve section (412) and the third sleeve section (413).

5. The disc brake according to any one of claims 1 to 4, characterized in that: Also includes: A plastic ring sleeve (500) is sleeved on the outer side surface of one end of the sliding pin (300) close to the bracket (200), the plastic ring sleeve (500) and the sliding pin (300) are axially limited and axially slideably matched with the caliper body (100); the elastic sealing sleeve (420) is sleeved on the outer side surface of the plastic ring sleeve (500), the elastic sealing sleeve (420) and the plastic ring sleeve (500) are sealed and axially slideably matched.

6. The disc brake according to claim 5, characterized in that A second limiting platform is formed on the outer side surface of the sliding pin (300), and one end of the plastic ring sleeve (500) away from the bracket (200) is axially limitedly matched with the second limiting platform.

7. The disc brake according to claim 6, characterized in that A first limiting portion and a second limiting portion (510) are formed on the outer side surface of the plastic ring sleeve (500) along the axial direction of the plastic ring sleeve (500); the first limiting portion is located between the bracket (200) and the second limiting portion (510); the first limiting portion abuts against or separates from the end surface of the protective sleeve (410) close to the bracket (200), and the second limiting portion (510) abuts against or separates from the lip of the elastic sealing sleeve (420).

8. The disc brake according to claim 7, characterized in that When the first limiting portion and the protective sleeve (410) are in contact with the end surface of the bracket (200), a first distance L1 between the end surface of the protective sleeve (410) facing the bracket (200) and the bracket (200) is 4 to 6 mm, and a second distance L2 between the lip of the elastic sealing sleeve (420) and the second limiting portion (510) is 20 to 23 mm.

9. The disc brake according to claim 5, characterized in that The interference between the lip of the elastic sealing sleeve (420) and the plastic ring sleeve (500) is 0.35-0.5 mm.

10. The disc brake according to claim 5, characterized in that A first gap is formed between the inner side surface of one end of the protective sleeve (410) close to the bracket (200) and the outer side surface of the plastic ring sleeve (500), and the radial dimension of the first gap is 0.2-0.5 mm.

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