KR100906992B1 - Damping shim for disc-type brake system - Google Patents

Abstract

Disclosed is a brake pad damping shim for use in a disc brake system. The damping shim is formed by a pair of slit portions formed in the predetermined area, a recessed portion in which a part of the damping shim between the pair of slit portions is pressed to protrude outward to a predetermined height, and a portion of the damping shim is removed. And a through hole for compensating for deformation of the damping shim when the recess is formed. Thus, when forming the anti-rolling structure in the damping shim, it is possible to minimize the area of plastic deformation of the steel material constituting the damping shim, and also to suppress the occurrence of deviation during processing, thereby effectively reducing the production time and cost of the product. At the same time, it is possible to provide a damping shim with better yield strength and flatness as compared to conventional sleeve structures.

Description

Damping shim for disc brake system {DAMPING SHIM FOR DISC-TYPE BRAKE SYSTEM}

The present invention relates to a disc brake system, and more particularly, to a damping shim for a brake pad for braking a disc (Disc) that rotates with a wheel of a vehicle.

In general, a brake system mounted on a vehicle is a device for decelerating, stopping or maintaining a vehicle while driving. The brake system converts kinetic energy during driving into thermal energy by a mechanical friction device and releases friction heat generated by the vehicle to the atmosphere. Refers to a device for braking. Such brake systems include drum brake systems and disc brake systems.

Disc brake system is a cross-sectional view of a general disc brake system as shown in Figure 1 as a way to obtain a braking force by pressing the disk-shaped disk that rotates with the wheel instead of the drum with a brake pad on both sides. As shown in FIG. 1, a disc brake system includes a caliper 10, a disc 20 that rotates with a wheel, and a pair of brake pads 30 disposed adjacent to both sides of the disc 20. Here, the caliper 10 includes a cylinder portion 40 and the finger portion 50 disposed on the other side, the cylinder portion 40 is provided with a piston 40a capable of moving forward and backward, the cylinder portion ( On the inner circumferential surface of 40, a seal 40b made of an elastic material for restoring the piston 40a when the braking hydraulic pressure is released is installed. In addition, a pair of brake pads 30 are respectively provided at one end of the piston 40a and one end of the finger portion 50, and the disk 20 is disposed between the pair of brake pads 30. As shown in FIG.

Looking at the operating method of the disk-type brake system of the above-described structure, as the driver presses the brake pedal, the hydraulic pressure generated in the master cylinder (not shown) by the booster (not shown) is transmitted to the caliper 10, As a result, the piston 40a in the cylinder portion 40 pushes the brake pad 30 on the cylinder portion 40 side, and the finger portion connected to the cylinder portion 40 by hydraulic pressure remaining in the cylinder portion 40 ( 50 pushes the other brake pad 30 to the disk 20 side. According to this operation, the two brake pads 30 press the disk 20 positioned therebetween, thereby braking. Then, when the driver releases the brake pedal, the piston 40a is restored to its original position by the elastic force of the seal 40b. Accordingly, the brake pad 30 and the finger 50 side of the cylinder portion 40 side are restored. The brake pads 30 are again spaced apart from the disk by a predetermined interval.

On the other hand, as shown in Figure 2a, the brake pad 30 is composed of a pad plate 32, a damping shim 34 and a friction pad 36, the friction pad 36 is a pad plate 32 It is attached to one side of the friction directly with the disk 20, the damping shim 34 is the vibration noise generated during the friction heat and braking caused by the friction of the disk 20 and the friction pad 36, the piston (40a) and It is to prevent the transfer to the finger portion 50 is attached to the other side of the pad plate 32 is disposed to face the friction pad (36).

Looking at the arrangement of the brake pad 30, the pressing force of the piston 40a and the finger portion 50 is transmitted to the pad plate 32 and the friction pad 36 through the damping shim 34, for example the piston 40a. ) Advances and brakes, the pad plate 32 is pushed in the rotational direction of the disc 20 by the braking torque formed between the disc 20 and the friction pad 36, and the pad plate 32. The damping shim 34 disposed between and the piston 40a is pushed in a direction opposite to the direction of rotation of the disk 20. Therefore, if the damping shim 34 is not strongly bound to the pad plate 32, the damping shim 34 is pushed away from the pad plate 32 by the sliding phenomenon, causing a problem of rupture or breakage.

Various efforts have been made to solve this problem, the most effective of which, as shown in Figures 2a and 2b, to form the recessed portion (32a) in the pad plate 32, the recessed in the damping shim (34) A method for forming a sleeve (34a) to be fitted to the part to prevent the damping shim (34) from being pushed by the pad plate (32) by the sleeve (34a) has been developed.

On the other hand, generally, the damping shim 34 forms a coating layer of a rubber-based base outer skin, and an adhesive layer for adhering the pad plate 32 to one side thereof is provided. It has a coated structure and protects the adhesive layer with a paper or vinyl cover to prevent foreign matter from adhering to the adhesive layer. Here, the substrate, the coating layer and the adhesive layer is selected as a material that can effectively reduce the frictional heat and vibration noise generated by the friction between the disk 20 and the friction pad 36, in particular cold rolled steel sheet (Cold Roll) Steel) or stainless steel, etc. may be used. Elastomers such as NBR (Nitrile Rubber) and ACR (Acrylic Rubber) may be used as the coating layer, and ACR (Acrylic), Silicon e or the like may be used.

Referring to Figures 3a to 3c, a method of manufacturing a damping shim of the structure shown in Figures 2a and 2b will be described as follows. First, the damping shim 34 including the substrate 1, the coating layer 2, the adhesive layer 3, and the cover 4 is prepared, and then a sleeve to be fitted into the recess 32a of the pad plate 32 is formed. A small diameter hole 34b is formed in advance in the region to be divided. Thereafter, as shown in FIG. 3A, the damping shim 34 having the hole 34b is disposed on the die 5, and then processed using a punch 6 having a larger diameter than the hole 34b. do. At this time, the die 5 is formed with a hole 5a having a diameter approximately the same as the diameter of the recess 32a formed in the pad plate 32. When the punch 6 penetrates the hole 34b, as shown in FIG. 3B, a portion of the damping shim around the hole 34b is deformed downward to form the sleeve 34a. In this case, as shown in FIG. 3C, a portion of the cover 4, the adhesive layer 3, and the coating layer 2 directly contacting the die 5 may be peeled off, and the coating layer 2 contacting the punch 6 may also be punched ( A part may come off by friction with 6).

FIG. 4A is a perspective view showing a state in which the leaving part of the cover 4, the adhesive layer 3, and the coating layer 2 remains after the punching process for forming the sleeve 34a in the damping shim 34. As such, when the leaving matter remains after the punching process, a separate process for removing the leaving matter is required. When the release material such as the adhesive layer or the coating layer is caught between the punch and the die, the production capacity of the product is reduced. In particular, when the leaving material remains in the manufacturing mold, surface defects such as pressing marks on the surface of the product may be generated. The removal of the debris is performed manually, which takes about 30 seconds per product. Therefore, when a large amount of product is produced, the overall product production time is increased, and further, the labor cost of manual labor increases the production of the product. The cost will also increase.

In addition, the sleeve 34a is formed by using plastic deformation of the substrate 1, where cracks (see region C) may occur in the sleeve 34a as shown in FIG. 4B. Such cracking often occurs when the diameter of the hole 34b previously formed in the damping shim 34 is too small compared to the diameter of the recess 32a. When the diameter of the hole 34b is increased to prevent cracking, the height of the finally formed sleeve is lowered, so that the minimum step height for preventing the sliding phenomenon of the damping shim 34 against the pad plate 32 is maintained. Since it becomes difficult, the anti-rolling function of the sleeve can be lowered.

On the other hand, in order for the damping shim to be strongly bound to the pad plate, the flatness of the damping shim should be maintained. In the damping shims of the structures shown in FIGS. Can be. In addition, the base material 1 of the damping shim may be formed by stacking two or more steel plates in multiple layers, and in case of excessively plastic deformation of the steel plates for forming a sleeve, there is an increased risk of peeling the steel plates of the multiple layers. FIG. 4C shows a state in which two steel plates 1a and 1b are peeled from each other after the sleeve is formed.

The present invention has been devised to solve the above-mentioned problems of the prior art, and minimizes the area where the base material of the steel material constituting the damping shim is plastically deformed, and also suppresses the occurrence of debris during processing, thereby effectively reducing product production time and cost. The aim is to provide a damping shim that can be reduced and at the same time has a better yield strength and flatness compared to conventional sleeve structures.

The damping shim of the brake pad used in the disc brake system according to the present invention includes a pair of slit portions formed by cutting a predetermined area of the damping shim to face each other, and a part of the damping shim between the pair of slit portions being pressed. And a recess formed to protrude outward by a predetermined height, and a part of the damping shim is removed and a through hole compensating for deformation of the damping shim when the recess is formed.

Here, the pair of slits may be formed in an arc shape or a straight line shape. In addition, the pair of slits is preferably formed perpendicular to the circumference around the axis of rotation of the disk that rotates with the wheel of the vehicle.

Furthermore, the depression may include a bent portion extending from the other region of the damping shim and bent to have a predetermined curvature, and a flat portion protruding outward from the other region of the damping shim and having a central portion flat.

On the other hand, the through hole is formed in the other region of the damping shim may be formed adjacent to the bent portion, may be formed in the central portion of the flat portion. In addition, two damping shims of the damping shim formed by a pair of slit portions, recesses and through holes are formed in the damping shim, and each of the damping shims may be formed to be symmetrical with respect to the center line of the damping shim.

The damping shim having the anti-roll structure according to the present invention can effectively prevent the damping shim from being pushed out of the pad plate by the rotational force of the disk rotating together with the wheel of the vehicle. In particular, in the case of a conventional sleeve structure to maintain the flatness of the damping shim due to the plastic deformation of the substrate according to the sleeve formation even if the height of the sleeve to form a minimum height to contact the recess formed in the pad plate to prevent the damping shim In the case of the anti-rolling structure according to the present invention, the plastic deformation of the substrate is minimized, so that the flatness of the damping shim can be improved compared to the related art while having the same or more anti-rolling effect.

Further, according to the present invention, even when the base of the damping shim is formed of a steel plate of multiple layers, it is possible to form the anti-rolling structure while preventing the respective steel plates from being peeled off or twisted. Therefore, the conventional sleeve structure is difficult to apply in the case of the damping shim composed of a multi-layered substrate, the anti-rolling structure according to the present invention can be easily applied to a multilayer structure as well as a single layer structure.

In addition, the anti-rolling structure according to the present invention does not generate the release of the coating layer, the adhesive layer or the cover during the processing of the damping shim, so that the productivity of the product is further improved and the defect rate is minimized. In particular, no additional process time and cost for removal of debris can be reduced, further lowering the cost of the product, and making it easier to apply the automated assembly process to the attachment of the damping shim to the pad plate.

Although a preferred embodiment of the present invention has been described so far, those skilled in the art will be able to implement in a modified form without departing from the essential characteristics of the present invention. Therefore, the embodiments of the present invention described herein are to be considered in descriptive sense only and not for purposes of limitation, and the scope of the present invention is shown in the appended claims rather than the foregoing description, and all differences within the equivalent scope of the present invention Should be interpreted as being included in.

Hereinafter, exemplary embodiments of a damping shim for a brake pad according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5A is a plan view of a damping shim according to the first embodiment of the present invention, and FIGS. 5B and 5C are partial cross-sectional views of the anti-rolling structure formed in the damping shim. FIG. 5B is a cross-sectional view taken along line II of FIG. 5A and FIG. 5C is a view of FIG. It is II-II sectional drawing of 5a. The anti-rolling structure formed in the damping shim according to the present invention is to replace the conventional sleeve structure, and a pair of slits 310 formed in a predetermined area A of the damping shim 300 and the slits 310 When drawing the recess 320 and the damping shim 300, a portion of the damping shim 300 is formed to protrude outward by a predetermined height. It includes a through hole 330 to minimize the deformation of the damping shim.

5B and 5C, the slit part 310 and the through hole 330 are formed by cutting a part of the damping shim main body 300 in accordance with the present invention. ) Is formed in a structure in which the area between the pair of slit portions 310 is drawn and recessed by a predetermined depth d1. For example, the slit 310 may be formed by using a punching tool having a cutting tip, and after forming the slit 310, drawing a region therebetween using a die and a punching tool. By processing, the depression 320 can be formed. The slit 310 and the depression 320 may be formed using one punching tool. In this case, cutting tips are formed at both corners corresponding to the slit 310, and an area between the cutting tips is formed. It is preferable to use a punching tool formed in a shape corresponding to the depression 320.

The above-described anti-rolling structure includes a plate-like substrate 301, a coating layer 302 formed on the outer surface of the substrate 301, an adhesive layer 303 and an adhesive layer 303 formed on the coating layer 302 on one surface of the substrate 301. After preparing the damping shim 300 including a cover 304 to protect the die, it is formed using a die and a predetermined punching tool, the forming process of the formation of the slit 310 and the through hole 330 It consists of a cutting process and a drawing process for forming the depression 320. Thus, the coating layer 302, the adhesive layer 303 or the cover 304 does not rub against the die or punching tool, so that part of the coating layer 302 is peeled off during formation of the anti-rolling structure, so that there is no fear of departures.

On the other hand, when drawing the recess 320, the area where the substrate 301 is deformed is much reduced compared to the area where the substrate is deformed in the conventional sleeve structure. That is, when forming one recess 320 in FIG. 5B, an area of a region (hereinafter, referred to as a bent portion (region B)) that is bent from another region of the damping shim 300 forms a circular sleeve structure. Much smaller than when. Therefore, when the conventional sleeve structure and the anti-rolling structure of the present invention are formed in the same area, the anti-rolling structure according to the present invention has better flatness of the damping shim after processing than the conventional sleeve structure. In addition, as shown in Figure 5a, because the through hole 330 formed around the depression 320, the deformation of the damping shim is minimized, thereby improving flatness. That is, the through hole 330 compensates the plastic deformation of the damping shim according to the formation of the recess 330, thereby preventing the flatness of the damping shim from being lowered. As a result, in the conventional sleeve structure, the flatness of the damping shim was about 0.26, but when the anti-rolling structure according to the present invention was formed, the flatness of the damping shim was improved to about 0.23. Furthermore, even when the base material 301 is formed of a multi-layered steel plate, the anti-rolling structure according to the present invention is formed with minimal plastic deformation, so that the base materials of the multi-layer peel off from each other by the shear distortion caused by the formation of the depression. Can be effectively prevented.

As a result of measuring the yield strength of the anti-rolling structure and the conventional sleeve structure according to the present invention through a universal testing machine, it was found that the case of the present invention has a better yield strength than the conventional case. For example, a conventional damping shim having a sleeve structure with a diameter of 13.3 mm and a step height of 1.3 mm has a yield strength of about 190.1 Kg, while a bone with anti-slim structure having a diameter of 13.5 mm and a depth of depression of 1.0 mm. The damping shim according to the invention showed a better yield strength of 251.9 Kg. This means that even when formed to a depth of depression smaller than the step height of the sleeve has a better yield strength, in addition to the conventional sleeve structure has to be formed with a limited step height in order to prevent cracking, but the anti-rolling of the present invention Since the structure has no possibility of cracking, the anti-rolling structure of the present invention is more advantageous for step height control than the conventional sleeve structure.

On the other hand, the recess 320 is inserted into the recess formed in the pad plate to prevent the damping shim from being pushed from the pad plate. Therefore, the depression 320 is preferably formed to have an outer shape substantially coincident with the outer portion of the recess formed in the pad plate. That is, when the concave portion is formed in a circular or rectangular shape, it is preferable that the outer portion of the recess 320 is also formed to have a circular or rectangular shape. Therefore, when the concave portion is formed in a circular shape, it is preferable that the pair of slit portions 310 are formed in an arc shape so that the outline of the recess 320 is kept circular. In addition, when the concave portion is formed in a quadrangle, it is preferable that the pair of slit portions 310 are formed in a straight line shape corresponding to one side of the quadrangle, so that the recessed portion 320 has a quadrangular shape as a whole. For reference, FIG. 5A illustrates a case in which a pair of slits 310 are formed in an arc shape to correspond to a circular recess, and FIG. 6 illustrates a pair of slits 310 to correspond to a rectangular recess. The case where it formed in linear form was shown.

In addition, in order to maximize the anti-rolling function of the depression, it is preferable that one side of the depression is formed perpendicular to the path where the damping shim is pushed relatively to the pad plate. That is, it is preferable to form the slit portion 310 perpendicular to the circumference (ie, the rotation path of the disk; L2 in FIG. 5A) around the rotation axis of the disk rotating with the wheel. However, the case where two slit portions 310 are formed in parallel with L2 is not excluded from the scope of the present invention.

Meanwhile, as shown in FIG. 5B, the recess 320 extends from the other region of the damping shim and is bent to have a predetermined curvature, and the flat portion protrudes outward from the other region of the damping shim and has a flat center. It may be composed of a portion (P). Here, the bent portion B (see FIG. 5B) is preferably formed to have a predetermined curvature. That is, it is preferable that the bending region B bent from the other region of the damping shim is rounded with a predetermined curvature R rather than having an angled corner. In addition, the flat portion (P) together with the bent portion (B) constitutes a depression fitted into the recess formed in the pad plate, through the structure that the side of the bent portion (B) and the flat portion (P) is caught on the side wall of the recess Damping shims are prevented from being pushed out of the pad plate. Herein, the flat portion P has a curvature in comparison with the bent portion B, and is formed in an approximately planar structure and does not need to be a perfect plane. The cover 304 attached to protect the adhesive layer 303 should be peeled off to attach the processed damping shim 300 to the pad plate. When the depression 320 is formed, the bent portion B is angled. Part of the cover 304 may be cut when it is processed to have a deep edge, and in this case, a part of the cover cut by hand must be removed, which may result in process inconvenience. Further, the bent portion B is preferably formed in a substantially straight shape (that is, the bent portion is straight as L3 in the plan view of FIG. 5A) in order to minimize the plastic deformation region of the substrate. In addition, the flat portion (P) is to maximize the contact area of the recess and the depression formed in the pad plate, through which the noise prevention and heat blocking function of the damping shim can be further improved.

Further, when the slit portion 310 is formed by using a method of punching by a predetermined width, a gap d2 may occur between the damping shim main body 300 and the recessed portion 320. ) And depression 320 can be formed simultaneously using one punching tool to minimize this spacing d2. In this way, when the slit 310 and the depression 320 are formed by one punching tool, it is more advantageous to control the dimensions of the depression 320 to match the recess formed in the pad plate, and the machining operation is furthermore. It's easy.

In addition, FIG. 5A shows an example in which two anti-rolling structures are formed in one damping shim. In this case, the two anti-rolling structures are formed to be symmetrical with respect to the center line L1 of the damping shim. It is more advantageous for prevention.

In addition, although FIG. 5A illustrates an example in which the through hole 330 is formed adjacent to the bent portion B in another region of the damping shim, as shown in FIG. 6, the through hole 330 is formed at the center of the flat portion P. FIG. It is also possible to form.

1 is a cross-sectional view showing a conventional disc brake system.

2A and 2B are views illustrating a conventional brake pad, FIG. 2A is a perspective view, and FIG. 2B is a sectional view taken along line II of FIG. 2A.

3A-3C are partial cross-sectional views illustrating a conventional method for forming a sleeve in a damping shim.

4A to 4C are views showing a defect that may occur when a sleeve is formed in a damping shim by the conventional method described with reference to FIGS. 3A to 3C.

Figure 5a is a plan view of a damping shim according to an embodiment of the present invention, Figures 5b and 5c is a partial cross-sectional view of the anti-rolling structure formed in the damping shim, Figure 5b is a cross-sectional view of the I-I of Figure 5a and Figure 5c It is II-II sectional drawing of 5a.

FIG. 6 is a partially enlarged view of a portion corresponding to region A of FIG. 5A as another embodiment of the damping shim according to the present invention.

Claims (9)

In the damping shim of the brake pads used in disc brake systems, A pair of slit portions formed by cutting a predetermined region of the damping shim to face each other; A depression formed in which a portion of the damping shim between the pair of slit portions is pressed to protrude outward by a predetermined height; A damping shim, characterized in that formed by removing a portion of the damping shim and comprises a through hole to compensate for the deformation of the damping shim when the depression is formed. The method of claim 1, Damping shim, characterized in that the pair of slits formed in an arc shape. The method of claim 1, Damping shim, characterized in that the pair of slits formed in a straight shape. The method according to any one of claims 1 to 3, Damping shim, characterized in that the pair of slits formed perpendicular to the circumference around the axis of rotation of the disk that rotates with the wheel of the vehicle. The method of claim 1, wherein the depression, A bent portion extending from another region of the damping shim and bent to have a predetermined curvature; And a flat portion protruding outward from the other region of the damping shim and having a central portion formed flat. The method of claim 5, The through hole is a damping shim, characterized in that formed in the other region of the damping shim adjacent to the bent portion. The method of claim 5, Damping shim, characterized in that the through hole is formed in the central portion of the flat portion. The method of claim 1, The damping shim, the damping shim characterized in that it comprises a plate-like substrate, a coating layer coated on the outer surface of the substrate, an adhesive layer formed on one surface of the substrate on which the coating layer is formed, and a cover protecting the adhesive layer. The method of claim 1, The pair of slit portions, the recessed portion and the through hole is formed of two anti-rolling structure in the damping shim, each of the anti-rolling structure is formed symmetrically with respect to the center line of the damping shim Damping break.

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