JPH09303440A - Disk brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk brake which enable positioning and assembling of an electrolytic-corrosion preventing member excellently. SOLUTION: A circular machining surface is provided concentrically with the center of a screw hole 18 located at the side face of a boss 17, and a locking member 27 whose distal end 27a locks with a machining reference surface 23, and two claws whose distal ends are locked with the circular machining surface are provided at an electrolytic-corrosion preventing member 9. A proximal end portion 27b of the lock member 27 locks with an end surface 5c of a carrier 5, and the distal ends of the two claws clamp the boss 17 being locked with the circular machining surface, and the distal end 27a of the locking part 27 engages with the maching reference surface 23 and sandwich the carrier 5 in association with an electrolytic-corrosion preventing member 26, so that the displacement of the electrolytic-corrosion preventing member 9 in direction of radial and axial is restricted, and resultantly, the electrolytic-corrosion preventing member 9 can be firmly fixed to the carrier 5. Since the claw is locked with the circular maching surface concentric with the screw hole 18 and assembled, the electrolytic-corrosion preventing member 26 can be positioned accurately to the boss 17.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a disc brake used in a vehicle.

[0002]

2. Description of the Related Art Conventionally, as an example of a disc brake,
A caliper that presses the brake pad against the disc and a carrier obtained by casting that supports the caliper movably in the axial direction of the disc are provided, and the carrier is bolted to a knuckle that is a non-rotating portion of the vehicle (hereinafter referred to as a knuckle). , Bolts for mounting).

In such a disc brake, it is necessary to carry out highly accurate assembly and alignment in order to perform a reliable and highly accurate braking function. For example, in order to hit the brake pad straight to the disc, the carrier knuckle attachment part is processed with high precision, or the pin hole into which a pair of support pins for supporting the caliper is inserted is processed with high precision. There is a need to. For this reason, a machining reference surface is formed, and the mounting portion, the pin hole, and the like are machined based on the machining reference surface to perform highly accurate assembly and alignment.

By the way, the carrier and the knuckle were generally made of iron, but recently, the weight reduction of the vehicle,
As part of higher performance, either the carrier or the knuckle may be made of aluminum instead of iron. However, like this one is aluminum
Further, if the other is made of an iron-based material and kept in contact with it, the aluminum member may be corroded by an electrochemical action. Therefore, in order to avoid this, an electrolytic corrosion preventing member is generally interposed between the two.

As an example of a disc brake having this electrolytic corrosion preventing member, there is a disc brake configured as follows. In this disc brake, a convex boss having a screw hole is provided on the surface side of the carrier, which is separated from the disc, and an electrolytic corrosion preventing member is interposed between the boss and the knuckle for mounting in the screw hole. The carrier is attached to the knuckle by screwing bolts.

On the disk side surface of the carrier,
While the working reference surface is formed by cutting the portion that has been raised in advance in the casting stage,
The part that is not raised is left as a casting surface in the cast state, and a step is formed between the processing reference surface and the casting surface. In addition, a casting surface in a cast state is left on the side surface portion of the boss.

Further, the electrolytic corrosion preventing member is bent in the substantially ring-shaped electrolytic corrosion preventing member main body interposed between the boss and the non-rotating portion of the vehicle and the outer peripheral portion of the electrolytic corrosion preventing member main body. Formed on the outer surface of the electrolytic corrosion preventing member main body, and three positioning claws whose tip ends contact the side surface (cast surface) of the boss.
From a portion of the two positioning claw portions facing the central one, it is bent and extended so as to straddle one end portion of the carrier, and the tip side is bent, and a locking portion that is locked to the step is provided. Have

In this disc brake, the electrolytic corrosion preventing member is temporarily fixed to the carrier in advance so that the carrier can be attached to the knuckle via the electrolytic corrosion preventing member without any trouble. The carrier is attached to the knuckle in the smashed state.

The screw holes of the carrier are formed by using a drill 1 as shown in FIG. 12, for example. The drill 1 includes a holding portion (not shown), a drill body shaft 3 that is rotatably provided on the holding portion, and has a boss mounting surface processing portion 2 that processes a boss mounting portion on a lower surface side, and a drill body shaft 3 And a screw hole processing shaft 4 which is connected to the screw hole for processing and forming the screw hole of the boss.

[0010]

By the way, in the above-described disc brake, the electrolytic corrosion preventing member is positioned by engaging the positioning claw portion of the electrolytic corrosion preventing member with the side surface portion (cast surface) of the boss. Therefore, the screw hole of the boss and the hole of the body of the electrolytic corrosion preventing member (hereinafter referred to as the hole of the electrolytic corrosion preventing member) may be misaligned, and the mounting bolt may not be smoothly inserted into the screw hole.

Further, since the side surface of the boss is a casting surface and has a large dimensional tolerance, the positioning claw portion is engaged with the side surface of the boss to perform positioning as described above. There is a possibility that the tightening margin of the stop portion may be eliminated or may become excessively large to deteriorate the assembling property, and in some cases, the electrolytic corrosion preventing member may be deformed by the assembling.
Incidentally, in order to properly position the electrolytic corrosion prevention member, it is conceivable to form a planar processing portion on the carrier using a milling machine or the like, but in this case, a lot of processing man-hours and processing time are required, The actual situation is that it has not been able to be properly positioned as the positioning of the electrolytic corrosion preventing member.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disc brake which can favorably position and assemble the electrolytic corrosion preventing member.

[0013]

According to the present invention, in order to achieve the above object, a screw hole is formed on a surface of a carrier that supports a caliper movably in an axial direction of a disk, the surface being separated from the disk. A convex boss is provided, an electrolytic corrosion preventing member is interposed between the boss and the non-rotating portion of the vehicle, and the carrier is attached to the non-rotating portion of the vehicle by screwing a bolt into the screw hole. An arcuate machining surface that is concentric with the screw hole and extends along the longitudinal direction of the screw hole is formed on a side surface portion of the boss, and the electrolytic corrosion preventing member is provided between the boss and the non-rotating portion of the vehicle. And a substantially ring-shaped electrolytic corrosion preventing member main body interposed between the carrier and the outer peripheral portion of the electrolytic corrosion preventing member main body is bent and extends so as to straddle one side end of the carrier, and the tip side is bent to form the carrier. Added to the surface of the disk side of A securing portion secured to the reference surface, characterized in that the electrolytic corrosion prevention member is formed by bending the outer peripheral portion of the main body distal end side and a claw portion for engaging the arcuate working surface.

[0014]

DETAILED DESCRIPTION OF THE INVENTION A disc brake according to an embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, 5 is an iron carrier obtained by casting. The carrier 5 has a plate-shaped leg portion 6 that is bent in a substantially U-shape, and one surface of the leg portion 6 (a surface that is separated from the disk 7; the right side in FIG. 1; hereinafter, referred to as the back surface) 5a side is an aluminum knuckle 8 side , And is attached to the knuckle 8 as will be described later with the electrolytic corrosion prevention member 9 having an insulating film formed on the spring steel interposed therebetween.

The legs 6 of the carrier 5 extend from the legs 6 to the other surface (the surface on the side of the disk 7; the left side in FIG. 1, hereinafter referred to as the surface) 5b and are arranged in parallel with each other, and the tip ends are connected to each other. A pair of rod-shaped arms 10 are formed. A protrusion 13 is formed on the arm 10 forming portion in a direction opposite to the arm 10. A flexible boot 12 is mounted between the protrusion 13 and the caliper 11 that presses the brake pad 15 against the disc 7. The protrusion 13 and the arm 10 are formed with a hole 14 extending along the longitudinal direction of the arm 10. A pair of pins 16 provided on the caliper 11 are movably inserted into the holes 14. Then, pin 1 into the hole 14 like this
By movably inserting carrier 6, carrier 5
The caliper 11 is movably supported in the axial direction of the disk 7.

As shown in FIGS. 2 and 5, a pair of bosses 17 are formed so as to project in the vicinity 6a of the bent portion of the leg portion 6 on the back surface 5a of the carrier 5. The boss 17 is formed with a screw hole 18 penetrating from the back surface 5a to the front surface 5b. On the side surface of the boss 17, concentric with the screw hole 18,
And two arc-shaped processing surfaces 1 along the longitudinal direction of the screw hole 18
9 is formed. The diameter of the circle including the two arcuate processing surfaces 19 is set to the length B as shown in FIG.

At the casting stage, the boss 17 has a boss body 20 having a diameter A as shown in FIG. 6, and a pair of boss protrusions 2 formed so as to project from the side surface of the boss body 20 so as to face each other.
1 and the distance between the top surface portions 21a of the pair of boss protrusions 21 including the center of the boss body 20 is set to be the length C (A <C).

The boss 17 shown in FIG. 6 is processed by using the drill 1 shown in FIG. 11, and as shown in FIGS. 3 and 4, the screw hole 18, the upper surface 17a of the boss 17, and the circle. An arc-shaped processed surface 19 is formed. This drill 1
From a holding part (not shown), a drill body shaft 3 rotatably provided on the holding part, and a screw hole machining shaft 4 provided in the center of the drill body shaft 3 and forming a screw hole 18 of a boss 17. The drill body shaft 3 has a screw hole drilling shaft 4
An annular groove 22 centered on is formed. in this case,
The diameter of the side wall (outer side) 22a of the annular groove 22 is B (A <B <
It is set to C). Then, by operating the drill 1, a screw hole 18 is formed in the screw hole processing shaft 4,
The bottom surface 22b of the annular groove 22 is used to machine the upper surface 17a of the boss 17, and the side wall (outer) 22a is used to form the arc-shaped machined surface 19
Is formed.

The upper portion of the surface 5b of the carrier 5 is formed so as to be higher than the lower portion, and the raised portion on the upper side is processed to form a processing reference surface 23. A step 25 is formed by the processing reference surface 23 and the lower casting surface 24 left in the cast state. The holes 14, the projections 13, the screw holes 18 and the like are formed by aligning them on the basis of the processing reference surface 23.

As shown in FIGS. 1 and 7, the electrolytic corrosion preventing member 9 has a ring-shaped electrolytic corrosion preventing member body 26 that covers the upper surface 17a of the boss 17. Electrolytic corrosion prevention body 2
As shown in FIG. 9 and FIG. 1, 6 is a side surface shape extending from the outer peripheral portion of the electrolytic corrosion preventing member main body 26 to the surface 5b side of the leg 6 of the carrier 5 and straddling one end 5c of the carrier 5. Is approximately V
A letter-shaped locking portion 27 is formed. A tip portion 27a of the locking portion 27 is bent and is locked to the processing reference surface 23.

Further, as shown in FIGS. 8 and 10, two claw portions 28 having a substantially V-shaped side surface are formed at the opposite portions of the outer periphery of the electrolytic corrosion preventing member body 26, A tip portion 28a of the claw portion 28 is adapted to engage with the arcuate machining surface 19. The locking portion 27 and the two claw portions 2
8 is formed by bending the electrolytic corrosion prevention member main body 26. The locking portion 27 and the one claw portion 28 before this bending process are shown by a chain double-dashed line in FIG. A hole 8a is formed in advance in the knuckle 8 so as to correspond to the screw hole 18, and a bolt 29 is screwed into the screw hole 18 through the hole 8a and the hole 26a formed in the electrolytic corrosion preventing member main body 26. By this screwing, the carrier 5 is fixed to the knuckle 8 with the electrolytic corrosion preventing member 9 interposed therebetween.

Then, the assembly of the electrolytic corrosion preventing member 9 to the carrier 5 is performed as follows. That is, first, the locking portion 27 of the electrolytic corrosion preventing member 9 is placed on the one end 5c of the carrier 5 so that the electrolytic corrosion preventing member main body 26 faces the upper surface portion 17a of the boss 17. Next, while pulling the electrolytic corrosion preventing member main body 26 downward in FIG. 1 to open the locking portion 27, the nail portion 2
The tip side of 8 is locked to the arcuate machining surface 19. After that, by pressing the portion of the electrolytic corrosion prevention member body 26 on the side where the locking portion 27 is formed (upper side in FIG. 1) against the upper surface portion 17a of the boss 17, the tip portion 27a of the locking portion 27 is engaged with the processing reference surface 23. . Then, by sandwiching the electrolytic corrosion prevention member main body 26, the locking portion 27, and the claw portion 28, the electrolytic corrosion prevention member 9 is held by the carrier 5 by the elastic force of the locking portion 27 and the claw portion 28. Assembly work is completed.

In the disc brake constructed as described above, the base end side portion 27b of the locking portion 27 is locked to the one side end portion 5c of the carrier 5 and the tip end portions 28 of the two claw portions 28.
Since a is locked to the arcuate processing surface 19 and holds the boss 17 with elastic force, the electrolytic corrosion preventing member 9 is restricted from moving in the radial direction of the boss 17. Also,
Since the tip portion 27a of the locking portion 27 engages with the machining reference surface 23 and clamps the boss 17 (carrier 5) together with the electrolytic corrosion preventing member body 26 with elastic force, the electrolytic corrosion preventing member 9 moves in the axial direction. Is regulated. In this way, the electrolytic corrosion preventing member 9 is restricted from moving in the radial direction and the axial direction of the boss 17, so that the electrolytic corrosion preventing member 9 can be reliably fixed to the carrier 5.

Further, an arcuate machined surface 1 concentric with the screw hole 18
Since the claw portion 28 is engaged with and assembled to the connector 9, the hole 26a of the electrolytic corrosion preventing member main body 26 and the screw hole 18 of the boss 17 can be accurately aligned. As described above, since the highly accurate alignment is performed and the electrolytic corrosion preventing member 9 is securely fixed to the carrier 5 as described above, the electrolytic corrosion preventing member main body 26 is fitted into the screw hole 18 of the boss 17. Since it is possible to prevent the holes 26a from being displaced, it is possible to prevent the bolts 29 from coming into contact with the electrolytic corrosion preventing member main body 26 during the assembling work of the bolts 29, so that the bolts 29 can be smoothly assembled.

After this, the carrier 5 to which the electrolytic corrosion preventing member 9 is temporarily fixed as described above is screwed into the screw hole 18 of the knuckle 8
The carrier 5 is fixed to the knuckle 8 in a state in which the electrolytic corrosion preventing member 9 is assembled by aligning the bolt 29 with the screw hole 18 and aligning it with the hole 8a.

In the present embodiment, the machining of the arcuate machining surface 19 is carried out simultaneously with the machining of the screw hole 18 of the boss 17, so that a machining surface for temporarily fixing the electrolytic corrosion preventing member 9 to the carrier 5 is separately provided. Therefore, it is possible to reduce the number of processing steps and the processing time. Further, since the arc-shaped machined surface 19 is formed by machining, the dimensional tolerance is smaller than that in the case of casting (the dimensional tolerance in the case of casting is ± 1 while that in the case of machining is dimensional tolerance). Is ±
0.25. ) Is possible, and thereby, the variation in the tightening margin of the tip end portion 27a of the locking portion 27 is reduced, and the assembly can be performed with a stable assembling force.

Further, in the above-mentioned prior art, the locking portion of the electrolytic corrosion preventing member straddles one end of the carrier, and the central one of the three positioning claws faces the one end of the carrier. Although the electrolytic corrosion preventing member is fixed to the carrier so as to straddle the other side end portion, in contrast to this, in the above embodiment, the central positioning claw portion is eliminated to prevent electrolytic corrosion. Since the member 9 is securely fixed, since the central positioning claw portion is eliminated, interference with surrounding parts can be suppressed and the degree of freedom of arrangement can be increased.

In the above embodiment, the case where two arcuate machining surfaces 19 and two locking portions 27 are provided is taken as an example.
One arcuate machining surface and one that is locked to this arcuate machining surface
Alternatively, three or more locking portions may be provided. In addition, three or more arc-shaped processed surfaces and three or more locking portions that are locked to the arc-shaped processed surfaces may be provided.

[0029]

As described above, according to the present invention, the base end side portion of the locking portion is locked to one side end portion of the carrier, and the tip portion of the claw portion is locked to the arcuate machining surface. By sandwiching the boss with elastic force, the electrolytic corrosion prevention member is restricted from moving in the radial direction of the boss, and the tip of the locking portion engages with the machining reference surface, and the electrolytic corrosion prevention member body Since the boss (carrier) is sandwiched by the elastic force and the movement of the electrolytic corrosion preventing member in the axial direction is restricted, the electrolytic corrosion preventing member can be securely fixed to the carrier.

Further, since the pawl portion is engaged and assembled with the arcuate machining surface concentric with the screw hole, the hole of the electrolytic corrosion preventing member main body and the screw hole of the boss can be accurately aligned. Due to such highly accurate alignment, and as described above, the electrolytic corrosion preventing member is securely fixed to the carrier, so that the hole of the electrolytic corrosion preventing member main body is not displaced from the screw hole of the boss. Since the bolts can be suppressed, the bolts can be prevented from coming into contact with the body of the electrolytic corrosion preventing member during the assembling work, and the bolts can be smoothly assembled.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a disc brake according to an embodiment of the present invention.

FIG. 2 is a front view showing a carrier of the disc brake.

FIG. 3 is a sectional view taken along line XX of FIG.

FIG. 4 is an enlarged view showing a boss of the carrier of FIG.

5 is a view taken along the arrow T of FIG.

FIG. 6 is a view of the carrier of FIG. 4 in a cast state before processing.

FIG. 7 is a perspective view showing an electrolytic corrosion preventing member used for the disc brake of FIG.

FIG. 8 is a plan view of the electrolytic corrosion preventing member.

9 is a sectional view taken along the line YY of FIG.

10 is a sectional view taken along the line ZZ of FIG.

11 is a sectional view showing a drill for forming a screw hole of the disc brake of FIG.

FIG. 12 is a cross-sectional view showing a drill for forming a screw hole used in an example of a conventional disc brake.

[Explanation of symbols]

 5 Carrier 7 Disk 8 Knuckle 9 Electrolytic Corrosion Preventing Member 11 Caliper 17 Boss 18 Screw Hole 19 Arc-shaped Machining Surface 23 Machining Reference Surface 26 Electrolytic Corrosion Preventing Body 27 Locking Part 28 Claw

Claims (1)

[Claims] 1. A convex boss formed with a screw hole is provided on a surface of a carrier that supports a caliper movably in an axial direction of the disk, the surface being separated from the disk, and the boss and a non-rotating portion of a vehicle. An electrolytic corrosion prevention member is interposed between the carrier and the carrier is attached to the non-rotating portion of the vehicle by screwing a bolt into the screw hole, and the side surface of the boss is concentric with the screw hole, and An arc-shaped machined surface along the longitudinal direction of the screw hole is formed, and the electrolytic corrosion preventing member is a substantially ring-shaped electrolytic corrosion preventing member main body interposed between the boss and the non-rotating portion of the vehicle, The electrolytic corrosion preventing member main body is bent and extends from the outer peripheral portion so as to straddle one side end portion of the carrier, and the front end side is bent and locked to a processing reference surface formed on the disk side surface portion of the carrier. Locking part and the electrolytic corrosion preventing member body A disc brake, which has a claw portion that is formed by being bent on the outer peripheral portion and whose front end side engages with the arcuate machining surface.