JPH0223736B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a brake friction pad used, for example, in an automobile brake device.
In particular, the present invention relates to a method of manufacturing a brake friction pad provided with a wear alarm piece that warns of wear when a friction material wears to the friction limit.

(Prior Art) This type of brake friction pad according to the prior art is shown in FIGS. 4 to 6. In the figure, 1 is a friction pad for applying braking by pressing a disk (not shown) that rotates together with the wheel, 2 is a back metal that constitutes the friction pad 1, and is attached to one side 2A of the back metal 2. A recessed portion 3 is formed by driving with a punch 9, which will be described later, and a caulked portion 4 is formed protruding from the other side surface 2B. Reference numeral 5 denotes a friction material that wears out while providing braking by frictionally engaging with the disk. The friction material 5 is made of a resin material with a substrate made of sintered metal, asbestos, or the like. The friction material 5 is formed under pressure on one side 2A of the back metal 2. At this time, the resin material of the friction material 5 is filled into the concave portion 3 of the back metal 2, and as a result, the back metal 2 and the friction material The engagement force of No. 5 is strengthened. Reference numeral 6 denotes an abrasion alarm piece whose base end 6A side is fixed to the caulking part 4 of the back metal 2. The abrasion alarm piece 6 is arranged along the side surface from the other side 2B of the back metal 2, and its tip 6B is attached to the caulking part 4 of the back metal 2. It is in a state of protruding from one side 2A.

The friction pad having the above-mentioned structure has conventionally been manufactured as follows.

That is, FIG. 4 shows a caulking part forming process for forming the caulking part 4 on the back metal 2. As shown in FIG. In the figure, 7 is a die, and the die 7 has a die hole 8 with a hole diameter d ₁ formed therein. To form the caulked portion 4 on the back metal 2 using the die 7, the other side 2B of the back metal 2 is brought into contact with the die 7, and the punch 9 is driven into the die hole 8 from the one side 2A. Here, the diameter d ₂ of the tip 9A of the punch 9 is larger than the hole diameter d ₁ of the die hole 8, and the tip surface 9
B is formed perpendicularly to the outer circumferential surface 9C, so one side 2A of the back metal 2 has a recessed part _{3B having a bottom part 3B} perpendicular to the straight face part 3A, which is an inner circumferential surface with an inner diameter d2. 3 is formed. On the other hand, due to the driving force of the punch 9, a part of the backing metal 2 protrudes from the other side surface 2B and is guided into the die hole 8 to form a cylindrical caulked part 4 having a diameter _d1 .

As described above, the friction material 5 is fixed to one side 2A of the back metal 2, which has the caulked portion 4 formed on the other side 2B. This is the friction material fixing process. Since the friction material 5 contains the resin material as a composition as described above, when the friction material 5 is pressure-molded onto the side surface 2A of the back metal 2, the resin material is also filled into the recessed portion 3. (See Figure 5).

Next, a wear warning piece 6 is fixed to the back metal 2. This is the caulking process shown in FIGS. 5 and 6. Here, a caulking part fitting hole 6C is provided on the base 6A side of the wear alarm piece 6, and the wear alarm piece 6 is formed by fitting the caulking part 4 into the caulking part fitting hole 6C. One side 2A along the side from side 2B
placed on the side. Thereafter, with the outer surface of the friction material 5 in contact with the support base 10, the caulking portion 4 is strongly hit in the direction of arrow A with a tool 11 such as a hammer to form a caulking mark 4A, thereby forming a wear alarm piece. Fix 6.

(Problems to be Solved by the Invention) Although the friction pad according to the prior art is manufactured as described above, it has the following drawbacks.

That is, when caulking the caulking part 4, the caulking part 4
A vertical caulking force F is applied from the upper end side toward the bottom surface portion 3B of the recessed portion 3. The bottom surface portion 3B is a surface perpendicular to the caulking force F, and the caulking force F acts on the center of the bottom surface portion 3B, but the caulking force F acting in the vertical direction causes the caulking portion 4 to It is pressed by the center of 3B, becomes a bulge 4B, and protrudes into the recess 3. As a result, there is a drawback that the caulking marks 4A of the caulked portion 4 are reduced and the adhesion force of the wear alarm piece 6 is weakened.

In addition, in the process of forming the bulge 4B in the concave part 3 by the caulking force F, a force is applied to the friction material 5 filled in the concave part 3 to cause it to separate from the backing metal 2. There is a disadvantage that the adhesion force of the friction material 5 to the friction material 5 is impaired.

Furthermore, as a result of the protruding portion 4B protruding into the recessed portion 3, the depth of the recessed portion 3 becomes shallow, which also causes a disadvantage in that the adhesion force of the friction material 5 is impaired.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and when the caulked portion is caulked, it is possible to prevent the caulked portion from escaping into the recessed portion, to obtain a sufficient caulking mark, and to prevent the wear warning piece from escaping. An object of the present invention is to provide a method for manufacturing a friction pad for a brake, which can be securely fixed and enhances the fixing force of a friction material.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the means adopted by the present invention is to form a concave portion on one side of the backing metal, thereby creating a caulking portion on the other side of the backing metal. A caulking part forming step of protrusion molding, a friction material fixing process of fixing a friction material to one side of the back metal, and a caulking process of caulking the caulking part after fitting the base of the wear alarm piece to the caulking part. A method of manufacturing a brake friction pad comprising: a concave portion formed by stamping in the caulking portion forming step; a straight surface portion whose inner circumferential surface is formed to have the same diameter; and a tapered surface part located in between and formed into an inclined surface or a curved surface, and the diameter of the caulked part is
d ₁ , the inner diameter of the straight surface portion is d ₂ , and the diameter of the tip of the bottom portion is d ₃ , and the straight surface portion is formed with a relationship of d ₂ >d ₁ >d ₃ .

(Function) By manufacturing in this way, the crimping force that acts on the crimping part during the crimping process is not concentrated on the bottom of the recessed part, but is dispersed along the tapered surface part to the straight surface part side, unlike the conventional technology. Since there is no bulge on the bottom side, the adhesion of the wear alarm piece is increased,
Furthermore, due to the formation of the straight surface portion, the friction material within the recessed portion is firmly coupled by the tightening force acting on the straight surface portion.

(Example) Hereinafter, an example of the present invention will be described in detail based on FIGS. 1 to 3. Note that the same components as those in the prior art described above are given the same reference numerals and their explanations will be omitted.

In the figure, 21 is a friction pad manufactured by the method of the embodiment, 22 is a back metal that constitutes the friction pad, and one side 22A of the back metal 22 is a punch 2, which will be described later.
6 is driven in to form a concave portion 23, and a caulking portion 24 is formed protruding from the other side surface 22B. A friction material 25 made of a resin material with a substrate of sintered metal, asbestos, etc. is formed under pressure on one side 22A of the back metal 22, as in the prior art.

Next, a method for manufacturing the friction pad 21 having the above-described structure will be described. In order to form the caulking portion 24 protrudingly on the backing metal 22 described above, the backing metal 22 is attached to the die 7.
The other side surface 22B is brought into contact with the other side surface 22B, and the punch 26 is driven into the die hole 8 from the one side surface 22A. The diameter d ₂ of the tip 26A of the punch 26 is larger than the hole diameter d ₁ of the die hole 8, and
A so-called C chamfer 26C is provided so that the diameter d ₃ of the tip surface 26B is smaller than the hole diameter d ₁ of the die hole 8. As a result, the caulked portion 2 is
4, one side 22A of the back metal 22
, a straight surface portion 23A consisting of an inner circumferential surface having an inner diameter d ₂ larger than the diameter d ₁ of the caulked portion 24;
A recessed portion comprising a bottom portion 23B having a diameter d ₃ smaller than the diameter d ₁ of the caulked portion 24, and a tapered surface portion 23 consisting of an inclined surface formed between the bottom portion 23B and the straight surface portion 23A. 23 is formed. On the other hand, the diameter d ₁ of the caulking portion 24 formed protrudingly from the other side surface 22A of the back metal 22 is the same as that in the prior art. Therefore, in the caulking part forming process of this embodiment, the diameter d ₁ of the caulking part 24, the inner diameter d ₂ of the straight surface part 23A, and the diameter d ₃ of the bottom surface part 23B are as follows: d ₂ > d ₁ > d ₃ ...(1 ) is formed into a relationship.

Next, a friction material 25 is pressure-molded on one side 22A of the back metal 22 on which the concave portion 23 and the caulking portion 24 are formed as described above, and the resin material of the abrasion material 25 is also applied inside the concave portion 23. It is in a filled state.

Thereafter, the wear warning piece 6 is fixed to the back metal 22. The wear alarm piece 6 is disposed on one side 22A of the back metal 22 from the other side 22B to the side by fitting the caulking part fitting hole 6C into the caulking part 24.
The abrasion warning piece 6 is fixed to the back metal 22 by hitting the caulking portion 24 with the tool 11 in the direction of the arrow A to form a caulking mark 24A.

According to this embodiment, the diameter d ₃ of the bottom surface portion 23B of the recessed portion 23 provided in the back metal 22 is larger than that of the punch 26.
is used to form the caulked portion 24 to have a smaller diameter than the diameter _d1 , and the bottom surface portion 23B and the straight surface portion 2
3A is formed in the tapered surface portion 23C,
The caulking force F applied from the upper end of the caulking portion 24 is not concentrated on the bottom surface portion 23B as shown in FIG. 2, but is dispersed along the tapered surface portion 23C in the direction of the straight surface portion 23A. As a result, unlike conventional technology,
It is possible to reliably prevent the bottom surface portion 23B from bulging into the concave portion 23 and the caulking portion 24 from escaping to the concave portion 23 side, and to obtain sufficient caulking marks 24A to firmly fix the wear alarm piece 6. can.

Furthermore, according to this embodiment, since the crimping force F can be prevented from concentrating on the bottom surface 23B of the recessed part 23, the force in the direction of peeling off the friction material 25 from the back metal 22 can be reduced, and the friction material against the back metal 22 can be reduced. The adhesion force of 25 is not impaired. At the same time, since the bulge 4B described in the prior art is formed in the concave part 23 and the concave part 23 does not become shallow, the adhesion between the back metal 22 and the friction material 25 becomes stronger. be able to.

Furthermore, in this embodiment, since the straight surface portion 23A is formed in the concave portion 23 and the inner part thereof is the tapered surface portion 23C, when the caulking force F is applied, the force that tends to cause the friction material 25 to peel off is generated. acts only on the bottom surface portion 23B, and the straight surface portion 23
In contrast, at A, the force acts to tighten the inner portion of the concave portion 23 of the friction material 25. As a result, the caulking force F acts as a force that tries to escape into the straight surface portion 23A, that is, a tightening force that tightens the inner portion of the concave portion 23 of the friction material 25, and the friction material 25 can be fixed even more firmly. .

In this embodiment, the tip portion 26A of the punch 26 is described as having a C chamfer 26C, but a so-called R chamfer may be formed, and in this case, the tapered surface portion 23C becomes a curved surface.

(Effects of the Invention) The method for manufacturing a brake friction pad according to the present invention is as described in detail above, and the recesses stamped on the back metal in the caulking part forming process are formed on the straight face part and the bottom face side. Since it is formed by the tapered surface portion, the following effects can be achieved.

The caulking force applied to the caulking part during the caulking process is not concentrated on the bottom part but is distributed from the tapered surface part to the straight face part, which prevents the bottom part from bulging into the recessed part and escaping, thereby causing a wear alarm. Pieces can be firmly attached.

In relation to the above item, since the caulking force is not concentrated on the bottom part, the force in the direction of peeling the friction material from the back metal can be reduced, and a bulge is generated within the recess, making the recess shallower. It is possible to prevent this from occurring, and it is possible to strengthen the adhesion between the back metal and the wear material.

The caulking force applied to the caulking part during the caulking process is distributed from the tapered surface part to the straight surface part,
The straight surface portion acts as a force that tightens the friction material, and together with the above, it becomes possible to fix the friction material even more firmly.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is an explanatory diagram showing the process of forming the caulking part on the back metal, FIG. 2 is an explanatory diagram showing the state of caulking the caulking part, and FIG. Fig. 3 is a partial vertical cross-sectional view of the friction pad showing the assembled state, Figs. 4 to 6 show the prior art, Fig. 4 is an explanatory view showing the process of forming the caulking part on the back metal, and Fig. 5 is An explanatory diagram showing a state in which the crimped portion is crimped, and FIG. 6 is a partial vertical sectional view of the friction pad in an assembled state. 6... Wear alarm piece, 22... Back metal, 23... Concave portion, 23A... Straight surface portion, 23B... Bottom surface portion, 23C... Tapered surface portion, 24... Caulked portion, 25... Friction material.

Claims (1)

[Claims] 1. A caulking part forming step in which a concave portion is stamped on one side of the backing metal to protrude a caulking part on the other side of the backing metal, and a friction material is fixed on one side of the backing metal. A method for manufacturing a friction pad for a brake, which comprises a step of fixing a friction material, and a crimping step of crimping the crimped portion after fitting the base of the wear alarm piece into the crimped portion, the method comprising: The recessed part to be carved consists of a straight face part whose inner peripheral surface is formed to have the same diameter, and a tapered face part located between the straight face part and the bottom face part and formed into an inclined surface or a curved surface. The diameter of the caulked part is d ₁ , the inner diameter of the straight surface part is d ₂ , and the diameter of the tip of the bottom part is d ₃
A method for manufacturing a brake friction pad formed with the relationship of d ₂ > d ₁ > d ₃ .