JP5393435B2 - Disc brake pad - Google Patents

Description

  The present invention relates to a disc brake pad employed as a friction member of a disc brake for a passenger car, a truck, or the like.

  A manufacturing method of a disc brake pad composed of a friction material and a back plate (back plate) that supports the friction material will be described. Bonding of fiber base materials such as metal fibers, organic fibers, inorganic fibers, thermosetting resins, etc. Mixing process for mixing friction materials made of materials, organic and inorganic fillers, etc., pressing mold for pressing friction materials, frame mold, and thermoforming mold consisting of upper mold (press mold, frame mold) The friction material raw material mixture obtained in the process is put in, heated and pressed to form and adhere the friction material on the back plate, the heat treatment process to cure the thermosetting resin, and the friction surface is formed by grinding with a grindstone It is manufactured through a polishing process.

  The disc brake pad manufactured by the above process may generate brake noise due to its own vibration or vibration from the disc rotor during braking. As a countermeasure, both ends of the friction material of the disc brake pad may be used. It is known to form an inclined surface on the part.

Patent Document 1 discloses a method of forming an inclined surface of a friction material at the time of forming the friction material by heating and pressurizing the friction material in a molding die having a pressing die having an inclined surface. ing.
However, when the inclined surface is formed on the friction material by a thermoforming mold having a die having an inclined surface as in Patent Document 1 described above, the end portion is lifted by cracks, wrinkles, and friction material warpage. There is a problem that the appearance of the product is deteriorated and the commercial value is remarkably lowered.
This is because the friction material becomes inhomogeneous because the pressure applied to the central portion, the inclined surface portion, and the inclined surface portion of the friction material is different depending on the region.

  As a method for solving the above-mentioned problem, Patent Document 2 discloses a process for producing a preform having an inclined surface by preforming in which a powdery friction material material is pressed and solidified in a mold. A friction material having an inclined surface of a desired angle at the position of the inclined surface by heating and pressurizing in a molding die having the same opening shape as the preforming die, and bonding to the back plate A manufacturing method of a disc brake pad is disclosed in which the angle of the inclined surface with respect to the surface of the preform on the side to be made is larger than the angle of the inclined surface of the friction material.

  According to the invention of Patent Document 2, since there is a space between the molding die and the preform, the friction material material easily flows, so that the friction material as a whole acts in a uniform direction. When a friction material material having a relatively large base material content and poor fluidity is used, the friction material may be partially inhomogeneous, and the problem has not been solved.

JP 2004-324863 A JP 2006-083978 A

The present invention has been made to solve the above problems, and in a disc brake pad in which an inclined surface is formed on a friction material by molding, a friction material material having a relatively large amount of fiber base material and poor fluidity. Even in the case of using a disc brake pad, an object of the present invention is to provide a disc brake pad having a good appearance without causing cracks, wrinkles, and frictional material warpage at the ends.
Still another object of the present invention is to provide a disc brake pad that can uniformly mold the entire friction material having an inclined surface at the end portion, and can significantly improve the brake squeal suppression effect.

In order to achieve the above object, the present invention provides:
(1) In a disc brake pad having a friction material having an inclined surface formed by molding , the contour of the projected portion of the portion of the back plate where the friction material is bonded, on the surface side where the friction material of the back plate is bonded A disc brake pad, wherein a recess having an opening area smaller than a projected area of the inclined surface of the friction material is formed inside , and the recess is filled with the friction material,
(2) The disc brake pad according to (1) above, wherein the inclined surfaces are formed at both ends of the friction material,
( 3 ) The disc brake pad according to ( 1 ) or (2) above, wherein the shape of the recess formed in the back plate is substantially similar to the contour of the projected portion of the inclined surface.
( 4 ) The disk according to ( 1 ) or (3) above, wherein the bottom of the recess formed in the back plate is inclined in the same direction as the inclined surface formed on the friction material. Brake pads,
Is to provide.

  According to the present invention, in a disc brake pad having a friction material having an inclined surface formed by molding, a projection of a portion where the inclined surface of the friction material is formed on the surface side to which the friction material of the back plate is bonded. By forming a recess in the portion, when the friction material material is pressed by the stamping die, the friction material material flows into the recess and the entire friction material can be uniformly molded. Floating due to cracks, wrinkles, and frictional material warpage can be prevented. Further, since the friction material becomes homogeneous, the squeaking of the brake can be suppressed.

The perspective view which fractured | ruptured a part of disc brake pad concerning the Example of this invention. II-II sectional view in FIG. Front view illustrating a disc brake pad including friction materials having different forms The figure which shows the shaping | molding start state in the figure of the heating and pressure molding process of the disc brake pad of this invention The figure of the heating / pressure forming process of the disc brake pad of the present invention, showing the completed state BRIEF DESCRIPTION OF THE DRAWINGS It is a disc brake pad concerning Example 1 of this invention, (A) is the front view, (B) is a front view of a backplate, (C) is sectional drawing of the edge part of the disc brake pad which formed the inclined surface. 4A is a front view of a disc brake pad according to a second embodiment of the present invention, FIG. 4B is a front view of a back plate, and FIG. 5C is a cross-sectional view of an end portion of the disc brake pad having an inclined surface. FIG. 4A is a front view of a disc brake pad according to a third embodiment of the present invention, FIG. 5B is a front view of a back plate, and FIG. 5C is a sectional view of an end portion of the disc brake pad having an inclined surface. 4A is a front view of a disc brake pad according to Embodiment 4 of the present invention, FIG. 4B is a front view of a back plate, and FIG. 5C is a sectional view of an end portion of the disc brake pad having an inclined surface. 5A is a front view of a disc brake pad according to a fifth embodiment of the present invention, FIG. 5B is a front view of a back plate, and FIG. 5C is a sectional view of an end portion of the disc brake pad having an inclined surface. It is a disc brake pad concerning comparative example 1 of the present invention, (A) is the front view, (B) is a front view of a back plate, (C) is a sectional view of the end of the disc brake pad which formed the inclined surface.

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

<1> Disc Brake Pad FIGS. 1 and 2 show a disc brake pad 10 according to the present invention.
The disc brake pad 10 includes a plate-like back plate 20 and a friction material 30 bonded to one side of the back plate 20. The friction material 30 has a flat friction surface 31 at the center, and inclined surfaces 32 on both sides. , 32 are formed, and ridgelines 33, 33 are formed at the boundary between the friction surface 31 and the inclined surfaces 32, 32.

  The disc brake pad 10 according to the present invention is suitable for use in disc brakes for passenger cars, but can also be used in brakes for large trucks, railway vehicles, various industrial machines and the like.

<2> Back Plate In the present invention, the concave portion 21 is formed in the projected portion of the portion where the inclined surface 32 of the friction material 30 is formed on the bonding surface 20a side of the back plate 20 to which the friction material 30 is bonded.
The concave portion 21 functions to make the entire friction material 30 homogeneous by causing the friction material material to flow into the concave portion 21 when the friction material 30 having the inclined surface is simultaneously molded as described later.

<2.1> Opening shape of the recessed portion The opening shape of the recessed portion 21 formed in the back plate 20 is formed in a shape substantially similar to the contour of the projected portion of the inclined surface 32 or the inclined surface 32 of the friction material 30. The opening area is smaller than the projected area and is formed inside the outline of the projected portion of the inclined surface 32.

  When the opening shape of the concave portion 21 formed in the back plate 20 is substantially similar to the contour of the projected portion of the inclined surface 32 of the friction material 30, the friction material 30 becomes more homogeneous and the wear of the friction material 30 proceeds. The effect of suppressing the occurrence of squeal becomes remarkable.

<2.2> Bottom shape of the concave portion The bottom portion of the concave portion 21 is formed in a flat shape parallel to the bonding surface of the back plate 20 or the slope of the inclined surface 32 so as to be substantially parallel to the inclined surface 32. It is formed as an inclined surface inclined in the same direction.

  If the shape of the bottom part of the recessed part 21 formed in the back plate 20 is formed flat, manufacture of a back plate will become easy.

  The bottom surface of the recess 21 formed in the back plate 20 is formed so as to be inclined in the same direction as the inclined surface 32 of the friction material 30, and the friction material 30 is compared with the case where the bottom shape of the recess 21 is formed flat. Can be made more uniform.

<2.3> Backplate material and manufacturing method The backplate 20 is formed into a predetermined shape by punching with a press after forming a recess in a steel plate for automobiles or a steel plate for machine structure. Manufactured. If necessary, the binding hole with the friction material 30 may be formed by penetrating through a punching process.
In addition, the manufacturing method of said back plate 20 is typical, and is not restricted to this manufacturing method.

<3> Friction material The friction material 30 is a uniform mixture of friction material raw materials made of known raw materials such as fiber base materials, binders, and fillers using a mixer such as a Redige mixer or an Eirich mixer. The mixture is formed as a preform by pressurizing the mixture with a press, or the mixture is directly put into a molding die and heated and pressed.

  3A to 3D are front views of a plurality of types of disc brake pads 10 to which the present invention is applicable.

The disc brake pad 10 shown in FIG. 3A is of a type in which an inclined surface 32 is formed at one end of the friction material 30.
The disc brake pad 10 shown in FIG. 3B is of a type in which inclined surfaces 32, 32 are formed at both ends of the friction material 30, and two ridge lines 33, 33 of the inclined surfaces 32, 32 are parallel. It is.
This type is easy to deal with when the inclined surfaces 32 and 32 are polished with a grindstone.
The disc brake pad 10 shown in FIGS. 3C and 3D has inclined surfaces 32 and 32 formed at both ends of the friction material 30, and the two ridge lines 33 and 33 of the inclined surfaces 32 and 32 are not formed. It is a parallel type.

<4> Manufacturing Method of Disc Brake Pad A method of manufacturing the disc brake pad 10 will be described based on FIGS.
The case where a preformed preform 34 is used as a molding material made of the friction material used in this example will be described. However, a powdery friction material mixture itself may be used without preforming. Moreover, the granulated material of a friction material raw material mixture may be sufficient.

  The preform 34 is made by mixing a friction material material composed of a fiber base material such as a metal fiber, an organic fiber, an inorganic fiber, a binder such as a thermosetting resin, an organic or inorganic filler, and the like. The friction material prototype is molded by pressurizing.

FIG. 4 shows an example of a molding die for molding the disc brake pad 10.
The molding die includes an upper mold 41, a frame mold 42, and a pressing mold 43 that moves up and down in a space formed through the frame mold 42.
The frame mold 42 is formed with openings having substantially the same contour shape as the friction material 30 and the same size.
On both sides of the upper surface of the pressing die 43, inclined surfaces 43a for forming the inclined surface 32 on the friction material 30 are formed.

  The pressing mold 43 is stopped at an appropriate position in the frame mold 42, and the preform 30 is placed in the space of the frame mold 42. Next, the back plate 20 having the recesses 21 formed on the upper surface of the frame mold 42 is placed. The back plate 20 is placed at a predetermined position by a positioning member (not shown) formed on the frame mold 42.

  Then, as shown in FIG. 5, the upper die 41 is lowered and the pressing die 43 is raised, and heat and pressure are applied to the preform 34 to mold the friction material 30 and affix it to the back plate 20. As shown in FIG. 2, the disc brake pad 10 having the inclined surfaces 32, 32 formed at the ends is manufactured.

  The molding process of the friction material 30 will be described in more detail.

The central portion of the friction material 30 is pressed against the flat central surface excluding the inclined surface 43 a of the pressing die 43, compressed to a predetermined density, and attached to the flat surface of the back plate 20 as in the conventional case.
In the present invention, the concave portion 21 is formed in the projected portion of the portion where the inclined surface 32 of the friction material 30 is formed on the surface side of the back plate 20 to which the friction material 30 is bonded.
Therefore, when the end portion of the friction material 30 is pressed by the inclined surface 43 a of the pressing die 43, a part of the material of the friction material 30 flows into the concave portion 21 of the back plate 20. A substantially uniform pressure is applied at the end.
Part of the material of the friction material 30 that has flowed into the recess 21 is bonded to the inner peripheral surface of the recess 21.
Therefore, the friction material 30 as a whole becomes uniform, and cracks and wrinkles generated at the end of the friction material 30 of the disc brake pad 10 in the molding process, and lifting due to warping of the friction material 30 can be effectively prevented. In addition, a disc brake pad having a good appearance can be provided.

  In the present invention, the opening area, depth, and bottom shape of the recess 21 formed in the back plate 20 according to the inclination angle and volume of the inclined surface 32 of the friction material 30 so that the entire friction material 30 is uniform. Etc. are designed.

A friction material material having a relatively large fiber base content and poor flowability is mixed for 10 minutes with a Redige mixer, and the resulting friction material material mixture is put into a preforming mold, Pressure was applied at 35 MPa for 1 minute, and a preform having an inclined surface larger than the angle of the inclined surface to be formed on the friction material described in Patent Document 2 was formed.
A preform and a back plate that has been cleaned and surface-treated in advance are placed on a thermoforming mold consisting of a stamping die, a frame die, and an upper die having an inclined surface, and the molding temperature is 155 ° C. and the molding pressure is 40 MPa. After heating and pressure forming for 5 minutes at the bottom, a curing treatment is performed at 200 ° C. for 4 hours in a heat treatment furnace, and finally polishing is performed, and Examples 1 to 5 and Comparative Example 1 shown in FIGS. A disc brake pad for passenger cars was created.

  6 to 11, (A) is a front view of the disc brake pad, (B) is a front view of the back plate 20, and (C) is a cross-sectional view of an end portion of the disc brake pad in which the inclined surface 32 is formed. It is.

[Example 1]
6A to 6C show a disc brake pad according to the first embodiment.
In the disc brake pad 10 of this example, two ridge lines 33, 33 of the friction material 30 are formed in parallel to each other, and the shape of the recess 21 formed in the back plate 20 is a projected portion of the inclined surface 32 of the friction material 30. The shape is substantially similar to the outline of.
In this example, the bottom of the recess 21 is formed flat in parallel with the bonding surface of the back plate 20.

[Example 2]
FIGS. 7A to 7C show a disc brake pad according to the second embodiment.
In the disc brake pad 10 of this example, the two ridge lines 33, 33 of the friction material 30 are formed in parallel to each other, and the opening area is smaller than the projected area of the inclined surface of the friction material. It is formed inside the outline of the projection part.
In this example, the bottom of the recess 21 is formed flat in parallel with the bonding surface of the back plate 20.

[Example 3]
8A to 8C show a disc brake pad according to the third embodiment.
In the disc brake pad 10 of this example, the two ridge lines 33, 33 of the friction material 30 are formed in parallel to each other, and the opening area is smaller than the projected area of the inclined surface of the friction material. It is formed inside the outline of the projection part.
Further, in this example, the bottom of the recess 21 is formed so as to be inclined so as to be substantially parallel to the inclined surface 32.

[Example 4]
FIGS. 9A to 9C show a disc brake pad according to the fourth embodiment.
In the disc brake pad 10 of this example, the two ridge lines 33 of the friction material 30 are formed non-parallel to each other, and the shape of the recess 21 formed in the back plate 20 is the projection of the inclined surface 32 of the friction material 30. The shape is substantially similar to the contour of the part.
In this example, the shape of the bottom of the recess 21 is formed flat in parallel with the bonding surface of the back plate 20.

[Example 5]
10A to 10C show a disc brake pad according to the fifth embodiment.
The disc brake pad 10 of the present example has two ridge lines 33 and 33 of the friction material 30 formed non-parallel to each other, has an opening area smaller than the projected area of the inclined surface of the friction material, and has an inclined surface. It is formed inside the outline of the projected portion.
In this example, the bottom of the recess 21 is inclined so as to be in the same direction as the inclined surface 32.

[Comparative Example 1]
FIGS. 11A to 11C show a disc brake pad according to Comparative Example 1 of the present invention.
This example is a conventional disc brake pad, and the surface side of the back plate 20 to which the friction material 30 is bonded has a flat shape.

[Evaluation method]
The appearance of the product was confirmed visually. The results are shown in Tables 2 and 3.
The evaluation criteria for the appearance of the product are as follows: ◎ is in a good state without cracks, wrinkles, and floats, ◯ is a very fine crack, a level state in which wrinkles are seen but no problems, and Δ is a fine crack, wrinkles Is seen, but there is no problem level, x indicates a problem with cracks, wrinkles and floating.

In addition, in order to evaluate the brake squeal in a state where the inclined surface disappears due to use, the brake brake squeal test was performed by attaching the disc brake pads of Examples 1 to 5 and Comparative Example 1 in the state where the inclined surface disappeared to the actual vehicle. .
The results are shown in Tables 2 and 3. The evaluation criteria for brake squeal are as follows: ◎ indicates no squeal, ◯ indicates extremely squeal, Δ indicates squeak, and x clearly indicates squeal.

DESCRIPTION OF SYMBOLS 10 ... Disc brake pad 20 ... Back plate 20a ... Adhesion surface 21 (back plate) ... Recess 30 ... Friction material 31 ... Friction surface 32 ... Inclined surface 33 ... Ridge line 34 ... Preliminary product 41 ... Upper mold 42 ... Frame mold 43 ... Push mold 43a .... Inclined surfaces

Claims (4)

In a disc brake pad having a friction material having an inclined surface formed by molding,
A concave portion having an opening area smaller than the projected area of the inclined surface of the friction material is formed on the inner side of the projected portion of the portion where the inclined surface of the friction material is formed on the surface side where the friction material of the back plate is bonded. A disc brake pad, wherein the concave portion is filled with a friction material.   The disc brake pad according to claim 1, wherein the inclined surface is formed at both ends of the friction material. 3. The disc brake pad according to claim 1, wherein the shape of the recess formed in the back plate is substantially similar to the contour of the projected portion of the inclined surface. Disc brake pad according to claim 1 or 3 the bottom of the recess formed in the back plate, and having an be inclined in the same direction as the inclined surface which is formed into the friction material.

Images