JP2012149674A - Brake pad for disk brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake pad for disk brake device capable of preventing heat generated by braking from being transmitted to hydraulic fluid without increasing the weight while preventing premature wear of a fitting part between a hydraulic piston and a hydraulic cylinder, breakage of friction material and peeling of adhesion with a backing plate.SOLUTION: The brake pad for disk brake device includes: the friction material 7 which is arranged attachably to and detachably from a brake disk rotor rotating with a wheel and is arranged while facing the brake disk rotor; and the backing plate 8 which firmly fixes the friction material 7 thereto and brings the friction material 7 into pressure-contact with the brake disk rotor, wherein cavity, groove, hole 12 or the combination of them is formed on the backing plate 8.

Description

  The present invention relates to a brake pad used in a disc brake device, and more specifically, heat is transmitted to a brake caliper on the vehicle body side by effectively interrupting heat generated from a friction surface between a brake disc rotor and a brake pad during braking. The present invention relates to a brake pad that makes it difficult and quickly releases generated heat.

  Conventionally, a monocoque hydraulic piston-facing caliper body that integrally forms a pair of hydraulic working parts and a bridge part that spans the outer periphery of the brake disc rotor and connects the two hydraulic working parts is integrally cast or After forming by forging, the hydraulic cylinder part is formed by cutting the hydraulic cylinder hole of the hydraulic action part. The monocoque caliper body is divided into two parts for the vehicle inner side and the vehicle outer side at the bridge part that has been widely adopted before its appearance, and each hydraulic cylinder hole is formed by cutting individually. Later, the caliper body opening rigidity (rigidity in the direction in which the distance between the two hydraulic pressure action parts increases when hydraulic pressure is applied) is higher than the type where both are connected with bolts, so it is often used for high-performance cars and sports type cars Has been.

JP 2009-228729 A

  This monocoque caliper body, as described in the above-mentioned patent document 1, requires a space between the two hydraulic pressure working parts in order to secure a space for inserting and machining a cutting tool from one side opening. There was a problem of spreading beyond. In order to fill this wide gap, in Patent Document 1, the hydraulic piston is extended to the brake disc rotor side, but the force acting from the brake disc rotor during braking causes the caliper body hydraulic cylinder and hydraulic piston to There was a problem that a large reaction force acted on the fitting part and the fitting part was worn out early.

  Another possible solution is to fill the gap by increasing the thickness of the friction material of the brake pad without extending the hydraulic piston. However, the distance between the brake disk rotor and the back plate is widened. Not only is the friction material that can be used limited because the force acting from the rotor and the moment due to the distance increase, the friction material and the backing plate are easily peeled off, and the friction material is easily destroyed by the moment. There is a problem that heat generated by braking tends to accumulate inside the friction material, and the friction material is likely to be altered by heat.

  The brake pad according to the present invention has been made in view of these problems, and the first invention according to claim 1 is to increase the thickness of the back plate to which the friction material is bonded to press the friction material against the brake disc rotor. And it is comprised so that a cavity may be formed in the said back plate in the direction orthogonal to the thickness direction of a back plate.

  According to a second aspect of the present invention, the thickness of the back plate is increased so that a groove or a hole or a combination thereof is formed on the surface opposite to the side to which the friction material is bonded. It is what has been.

  According to a third aspect of the present invention, the back plate of the first or second aspect is made of a non-ferrous material such as an aluminum alloy.

  According to a fourth aspect of the present invention, the back plate according to the first or second aspect is composed of a polymer material such as resin or a non-golden material such as carbon fiber.

  The brake pad according to the first aspect of the present invention having the above-described configuration increases the thickness of the back plate without extending the hydraulic piston toward the brake disc rotor and without increasing the friction material portion of the brake pad. Since it is configured to form a cavity in a direction perpendicular to the thickness direction of the back plate, even if a braking force is applied from the brake disk rotor by braking, a moment in a direction that squeezes the hydraulic piston with respect to the hydraulic cylinder is generated. Because it is small, the fitting part between the hydraulic cylinder and the hydraulic piston of the caliper body does not wear out at an early stage, and the friction material and the back plate do not peel off, and the friction material is used. There is an effect that the material is not limited.

  In addition, since a cavity is formed in the back plate in a direction perpendicular to the thickness direction of the back plate, the weight is not increased. In addition, the hollow portion cuts off heat generated between the brake disc rotor and the friction material during braking and transmitted to the hydraulic piston through the friction material, and the fluid during running flows into the hollow portion. Since the cooling performance of the back plate is greatly improved, heat generated during braking is not easily transmitted from the hydraulic piston to the brake caliper, and the brake fluid is less effective because the working fluid inside the brake caliper exceeds the boiling point. There is an effect of not causing vapor lock.

  The brake pad according to the second invention having the above-described configuration is formed by thickening the back plate portion and forming a groove or a hole or a combination of these on the opposite surface of the back plate to the side to which the friction material is bonded. As in the case of the first invention, the fitting portion between the hydraulic cylinder and the hydraulic piston is not worn out at an early stage, and the friction material and the back plate are peeled off. In addition, there is an effect that the material used for the friction material is not limited.

  Further, since a groove or a hole or a combination of these is formed on the surface of the back plate opposite to the side to which the friction material is fixed, as in the first invention, an increase in weight is caused. In addition, the groove or hole or a combination of them cuts off the heat transmitted through the friction material during braking, and the running fluid flows into the groove or hole or a combination of them. By significantly improving the cooling performance of the back plate, it is difficult to transmit heat generated by braking to the hydraulic piston, and there is no effect of causing vapor lock.

  Further, in the second invention, the groove or hole or a combination thereof is formed on the surface of the back plate opposite to the side to which the friction material is adhered. There exists an effect that it can manufacture comparatively easily.

  The brake pad of the third invention having the above structure is lightweight because the back plate of the first invention or the second invention is made of a non-ferrous material such as an aluminum alloy, and the back plate is drawn. There is an effect that it can be manufactured at low cost by a method such as extrusion or press working.

  The brake pad according to the fourth invention having the above-described configuration is light in weight because the back plate of the first invention or the second invention is made of a polymer material such as a resin or a non-golden material such as carbon fiber. There is an effect that the back plate can be manufactured at low cost by a method such as injection molding.

The perspective view of the brake pad which shows the Example of 1st invention The front view of the brake pad which shows the Example of 1st invention The top view of the brake pad which shows the Example of 1st invention Sectional drawing which follows the AA line in FIG. The perspective view of the brake pad which shows another Example of 1st invention The front view of the brake pad which shows another Example of 1st invention Left side view of a brake pad showing another embodiment of the first invention Sectional drawing which follows the BB line in FIG. Rear view of a brake pad showing an embodiment of the second invention Sectional drawing which follows the CC line in FIG. Explanatory drawing which shows how power is transmitted in FIG. Front view showing a conventional brake caliper Plan view showing a conventional brake caliper Sectional drawing which follows the DD line in FIG. Sectional drawing which shows another prior art example in alignment with the DD line in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

  FIG. 12 shows a monocoque hydraulic piston in which a pair of hydraulic operating portions including a hydraulic piston 3 and a hydraulic cylinder 5 and a bridge portion that bridges the outer peripheral portion of the brake disc rotor 2 and connects both hydraulic operating portions are integrally formed. A front view of the opposed brake caliper 1 is shown, and FIG. 14 is a sectional view taken along the line DD of FIG. This monocoque brake caliper 1 was the mainstream before its appearance, after the caliper body 4 was divided into two parts for the vehicle inner side and the vehicle outer side at the bridge part straddling the brake disc rotor 2, and each was cut individually. The caliper rigidity (when the brake fluid pressure is applied and the brake disc rotor 2 is sandwiched between the brake pads 6 from both sides by the brake pad rotor 2 is compared with the brake disc rotor 2 in comparison with the type in which the two are tightened and connected with fastening bolts. Because it has a high rigidity) that is pushed back to the opposite side of the brake disc rotor 2 due to the reaction force from the brake, the rise of the braking force against the depression force of the brake pedal (not shown) is fast, and the proportional relationship between the two is good, so it is adopted for sports cars Has been.

  However, the brake caliper 1 of this monocoque structure requires a space for inserting a cutting tool from one side opening of the caliper body 2 as shown in the prior art document, and the inserted cutting tool is only the length to be processed. It is necessary to lengthen the length of the blade mounting portion so that the drive portion does not interfere with the workpiece even if it is moved. Further, since the portion of the hydraulic cylinder 5 to be cut requires a very high machining accuracy, a sufficient blade holding rigidity is required, and therefore, a portion for holding and driving the blade becomes large. Since this large cutting blade portion is inserted through the opening, the opening (interval between both hydraulic cylinders) is inevitably widened. In other words, the opening is considerably larger than the opening dimensions determined by the thickness of the brake disc rotor 2, the thickness of the friction material 7 of the brake pad 6, and the thickness of the back plate 8 plus the dimensional margin in each thickness direction. growing.

  Actually, in this type of brake caliper 1, the hydraulic piston 3 protrudes toward the brake pad 6 as shown in FIG. The braking force BF during braking is applied to the contact surface between the back plate 8 of the brake pad 6 and the hydraulic piston 3 in a direction perpendicular to the paper surface of FIG. A force of (BF × L1) / L2 is applied to the end B of the part, and a force of (BF × L1) / L2 + BF is applied to the end A as well. Therefore, early wear of the end portions A and B, the inner diameter of the hydraulic cylinder 5 and the outer diameter of the hydraulic piston 3, and looseness of the fitting portion and the hydraulic seal 9 and early wear occur.

  As a method for avoiding these problems, it is conceivable to reduce the protrusion L1 of the hydraulic piston 3 by thickening the friction material 7 of the brake pad 6 as shown in FIG. Actually, in the case of the brake pad 6 in FIG. 14, the thickness of the friction material 7 is about 10 mm and the thickness of the back plate 8 is about 5 mm. In FIG. There is a thicker one. However, in the case of this method, the thickness of the friction material 7 is considerably larger than the originally required thickness, so that the force acting from the brake disk rotor and the moment due to the distance between the brake disk rotor and the back plate are increased, and the friction material and the back plate are increased. Since the friction material is easily broken by the moment, the friction material that can be used is not limited, and heat generated by braking is likely to accumulate inside the friction material 7. However, there was a problem that it was easily changed by the heat. Further, since the friction material 7 is thick, the brake hydraulic pressure acting from the hydraulic piston 3 is consumed for compressive deformation of the friction material 7 and hardly acts as a pressing force of the brake disk rotor 2.

  1 is a perspective view of a brake pad according to a first embodiment of the first invention, FIG. 2 is a front view, FIG. 3 is a plan view, and FIG. 4 is a cross-sectional view taken along line AA of FIG. The brake pad 6 of the present invention has a thickness of 10 mm thick friction material 7 and two locking pin holes 11 through which a locking pin for suspending the brake pad 6 on the caliper body 4 is suspended at the top. It is composed of an iron back plate 8 having a thickness of 15 mm. A total of 31 through-holes with a diameter of 6 mm that penetrate in the vertical direction in FIG. With this configuration, it is not necessary to increase the thickness of the friction material 7 of the brake pad 6 and to increase the protrusion amount of the hydraulic piston 3 to the brake pad 6 side.

  Therefore, the early wear of the inner diameter of the hydraulic cylinder 5 and the outer diameter of the hydraulic piston 3 and the backlash of the fitting part and the hydraulic seal 9 do not occur. Moreover, the end part peeling of the adhesion part of the friction material 7 and the backplate 8 does not generate | occur | produce, and the friction material 7 does not destroy. Therefore, the material used for the friction material 7 is not limited.

  Further, the fluid inside the through-hole 12 has a heat insulating effect that makes it difficult to transmit the frictional heat generated by the sliding contact between the brake disk rotor 2 and the friction material 7 of the brake pad 6 to the hydraulic piston 3 by braking. Moreover, there is an effect that the frictional heat is quickly released when the fluid flows into the through-hole 12 by running. Due to these synergistic effects, frictional heat is transmitted to the hydraulic piston 3, the hydraulic fluid in the hydraulic chamber 10 and the hydraulic piping (not shown) boils, and bubbles are generated, so that a so-called vapor lock that makes it difficult for the brake to work effectively does not occur. Further, in this embodiment, since the through holes 12 are alternately arranged in two rows, the pressing force F against the brake pad 6 of the hydraulic piston 3 compresses the through holes 12 as shown in FIG. Since the reaction force R of the members on both sides of the hole 12 is efficiently supported, both weight reduction and securing of rigidity can be achieved.

  The through-hole 12 of the back plate 8 of the present embodiment is formed by drilling a 6 mm hole in a 15 mm thick iron plate, but the heated iron material is drawn or extruded in the direction of the plan view shown in FIG. In view of manufacturing cost, it is preferable to continuously form the hole including the hole by processing and then cut it into the shape of the front view of FIG. 2 with a laser or the like.

  In this drawing, two locking pin holes 12 are not provided in the general top of the head, but a type in which a single locking pin hole is provided in the center of the top of the brake pad as described in the prior art document. Although the type to provide is described, it cannot be overemphasized that this invention is applicable irrespective of the number of locking pin holes.

  FIG. 5 is a perspective view of a brake pad according to a second embodiment of the first invention, FIG. 6 is a front view, FIG. 7 is a plan view, and FIG. 8 is a sectional view taken along line BB in FIG. The structure of the thickness of the friction material 7 and the back plate 8 of the brake pad 6 of the present invention is the same as that of the first embodiment. In the case of this embodiment, the through holes 12 have a diameter of 6 mm, and a total of 18 holes are opened alternately in two rows in the left-right direction in FIG. With this configuration, the same effect as in the first embodiment can be obtained.

  Further, the brake caliper 1 is provided with a locking portion for receiving the braking force of the normal brake disc rotor 2 in the caliper body 4, and the side portion where the through hole 12 of the brake pad 6 is opened is connected to the locking portion. On the other hand, since a part of the through hole 12 is blocked, the heat dissipation effect due to the fluid flowing into the through hole 12 of the back plate 8 during traveling is reduced, but it is possible to avoid mud and the like from being clogged in the through hole 12, In addition, the heat insulating effect due to the presence of a cavity in the back plate 8 is maintained.

  The front view of the second invention is the same as FIG. 2 and FIG. FIG. 9 is a rear view of the embodiment of the second invention, and FIG. 10 is a sectional view taken along the line CC of FIG. Since the configuration of the thickness of the friction material 7 and the back plate 8 of the brake pad 6 of the present invention is the same as that of the first embodiment, early wear and fitting of the inner diameter of the hydraulic cylinder 5 and the outer diameter of the hydraulic piston 3 No backlash and premature wear of the hydraulic seal 9 and the frictional material 7 and the back plate 8 are not peeled off, and the friction material 7 is not shear broken. The basic effect that the material used for the friction material 7 is not limited is obtained as it is.

  In the case of the present embodiment, a total of 141 cooling holes 13 having a diameter of 6 mm and a depth of 13 mm are provided alternately in 10 rows vertically on the surface of the back plate 8 opposite to the side to which the friction material 7 is bonded. ing. Thereby, the heat insulation effect which makes it difficult to transmit the frictional heat which generate | occur | produced when the brake disc rotor 2 and the friction material 7 of the brake pad 6 slidably contact by braking to the hydraulic piston 3 is acquired. Moreover, there is an effect that the frictional heat is quickly released when the traveling wind passes through the cooling hole 13, and the vapor lock is less likely to occur. In addition, although the cooling hole 13 of a present Example is materialized by drilling, it is preferable on the manufacturing cost side to form a cooling hole simultaneously when punching the outer periphery of the backplate 8 by press work etc.

  The drawings relating to the embodiment of the third invention are the same as those shown in FIGS. The brake pad 6 of the present invention is made of a non-ferrous material such as an aluminum alloy while the back plate 8 in the first or second invention is made of iron. Non-ferrous materials such as aluminum alloys have better formability than iron materials, and can be molded at room temperature even when the iron materials have to be heated before being formed, and the back plate is drawn, extruded, It can be manufactured at low cost by methods such as press working. Further, as described above, the brake pad 6 according to the present invention can suppress the temperature rise of the back plate 8 due to braking by introducing a fluid during traveling, etc., so that it can be used even with a material such as an aluminum alloy that has a light weight and a low melting point. it can.

  The drawings relating to the embodiment of the fourth invention are the same as those shown in FIGS. The brake pad 6 of the present invention is made of a polymer material such as resin or a non-golden material such as carbon fiber, whereas the back plate 8 in the first invention or the second invention is made of iron. Yes. Polymer materials such as resins and non-golden materials such as carbon fibers are lighter and have better moldability than iron materials, and can be manufactured at low cost by methods such as injection molding. In addition, as described above, the brake pad 6 according to the present invention can suppress the temperature rise of the back plate 8 due to braking to a low level by introducing a fluid during traveling, etc. Therefore, the brake pad 6 is light in weight and heat resistant like a polymer material such as resin. Even materials with low properties can be used.

  The above-mentioned embodiment is illustrated for explanation, and is not limited to a brake pad used for a brake caliper having a monocoque structure having a pair of hydraulic pressure action portions straddling the outer periphery of the brake disc rotor. The present invention can also be applied to a brake pad used in a split type caliper or a brake caliper having a hydraulic pressure acting part only on one side. Further, the present invention is not limited to them, and can be changed and added without departing from the technical idea of the present invention that can be recognized by those skilled in the art from the description of the scope of claims.

  The present invention is not limited to a brake pad for a disc brake device, and has a friction material and a back plate that presses the friction material against the brake member, and is arranged so as to be able to contact and separate from the brake member. For example, it is effective for a brake pad of a type that presses only one side of a member to be braked that moves linearly, and can be applied to industrial equipment.

DESCRIPTION OF SYMBOLS 1 Brake caliper 2 Brake disc rotor 3 Hydraulic piston 4 Caliper body 5 Hydraulic cylinder 6 Brake pad 7 Friction material 8 Back plate 9 Hydraulic seal 10 Hydraulic chamber 11 Locking pin hole 12 Through hole 13 Cooling hole

Claims (4)

  A friction material disposed so as to be able to contact with and separate from a brake disc rotor that rotates together with the wheel and opposed to the brake disc rotor; and a back plate that is fixed to the friction disc and presses the friction material against the brake disc rotor. A brake pad for a disc brake device, comprising: a hollow formed in the back plate in a direction perpendicular to the thickness direction of the back plate.   A brake pad for a disc brake device, wherein a groove or a hole or a combination of these is formed on the surface of the back plate opposite to the side to which the friction material is bonded.   The brake pad for a disc brake device according to claim 1 or 2, wherein the back plate is made of a non-ferrous material such as an aluminum alloy.   The brake pad for a disc brake device according to claim 1 or 2, wherein the back plate is made of a polymer material such as a resin or a non-golden material such as carbon fiber.

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