JP3735826B2 - Disc brake - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disc brake used in a vehicle.
[0002]
[Prior art]
Conventionally, as an example of a disc brake, a caliper that presses a brake pad against the disc and a carrier obtained by casting that supports the caliper so as to be movable in the axial direction of the disc are provided. Some of them are attached to the knuckle, which is a part, with bolts (hereinafter referred to as mounting bolts).
[0003]
Such a disc brake needs to be assembled and aligned with high accuracy in order to perform a reliable and accurate brake function. For example, in order to apply the brake pad straight to the disc, the mounting part with the carrier knuckle is processed with high accuracy, or the pin hole into which the pair of support pins that support the caliper is inserted is processed with high accuracy so that the parallelism comes out. There is a need to. For this reason, a machining reference plane is formed, and the mounting portion and the pin hole are machined based on the machining reference plane to perform highly accurate assembly and alignment.
[0004]
By the way, the carrier and the knuckle were generally made of iron, but recently, either the carrier or the knuckle is made of aluminum by replacing one of the carrier and the knuckle with an iron as part of weight reduction and high performance of the vehicle. It may be. However, if one side is made of aluminum and the other side is made of an iron-based material and kept in contact with each other, an aluminum member may be corroded by electrochemical action. An electrolytic corrosion prevention member was interposed.
[0005]
As an example of a disc brake having this electrolytic corrosion preventing member, there is a disc brake configured as follows. This disc brake is provided with a convex boss formed with a screw hole on the surface side of the carrier that is separated from the disc, and an electrolytic corrosion prevention member is interposed between the boss and the knuckle to attach to the screw hole. The carrier is attached to the knuckle by screwing the bolt.
[0006]
On the disk side surface portion of the carrier, the processing reference surface is formed by cutting a portion that has been raised in advance in the casting stage, and the portion that has not been raised is left as a casting surface in the cast state, and processed. A step is formed between the reference surface and the casting surface. Further, a cast surface of the cast state remains on the side surface of the boss.
[0007]
The electrolytic corrosion preventing member is formed by bending a substantially ring-shaped electrolytic corrosion preventing member main body interposed between the boss and the non-rotating portion of the vehicle, and an outer peripheral portion of the electrolytic corrosion preventing member main body. From the portion of the three positioning claws that the tip end abuts on the side surface portion (casting surface) of the boss and the three positioning claws on the outer peripheral portion of the electrolytic corrosion preventing member main body, facing the center one, It has a locking portion that is bent and extended so as to straddle the one side end portion, the front end side is bent, and is locked to the step.
[0008]
And in this disc brake, the electric corrosion prevention member is temporarily fixed to the carrier in advance so that the carrier can be attached to the knuckle through the electric corrosion prevention member without trouble, and the electric corrosion prevention member is integrated. The carrier is assembled to the knuckle.
[0009]
In addition, the screw hole of the said carrier is formed using the drill 1 as shown, for example in FIG. The drill 1 includes a drill body shaft 3 having a holding portion (not shown) and a boss mounting surface processing portion 2 that is provided on the holding portion so as to be rotatable and that processes a mounting portion of the boss on the lower surface side. And a screw hole machining shaft 4 which is connected to the shaft and forms a screw hole of the boss.
[0010]
[Problems to be solved by the invention]
By the way, in the above-described disc brake, the electric corrosion prevention member is positioned by locking the positioning claw portion of the electric corrosion prevention member to the side surface portion (casting surface) of the boss. It may happen that the hole of the prevention member main body (hereinafter referred to as the electrolytic corrosion prevention member side hole) is displaced and the mounting bolt cannot be smoothly inserted into the screw hole.
[0011]
In addition, since the side surface portion of the boss is a cast surface, and its dimensional tolerance is large, as described above, the positioning claw portion is locked to the side surface portion of the boss and positioned. The tightening allowance is lost or excessive, and the assembling property is deteriorated. In some cases, the electrolytic corrosion preventing member may be deformed by the assembling.
In addition, in order to satisfactorily position the electrolytic corrosion prevention member, it is conceivable to form a planar processed portion on the carrier using a milling machine or the like, but in this case, a large number of processing steps and processing time are required, The actual situation is that it cannot be appropriate for positioning of the electrolytic corrosion preventing member.
[0012]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a disc brake capable of satisfactorily positioning and assembling the electrolytic corrosion prevention member.
[0013]
[Means for Solving the Problems]
According to the first aspect of the present invention, a convex boss formed with a screw hole is provided on a surface side of the carrier that supports the caliper so as to be movable in the axial direction of the disk, and is separated from the disk. An electrolytic corrosion preventing member is interposed between the rotating portion and the carrier is attached to a non-rotating portion of the vehicle by screwing a bolt into the screw hole, and the electrolytic corrosion preventing member includes the boss and the vehicle. A substantially ring-shaped electrolytic corrosion prevention member body interposed between the non-rotating part and a bent portion extending from the outer periphery of the electrolytic corrosion prevention member body so as to straddle one side end of the carrier. A bent portion that is bent and locked to a processing reference surface formed on the disk side surface portion of the carrier, and is bent to an outer peripheral portion of the electrolytic corrosion prevention member main body, and a distal end side is engaged with the boss . disc brake and a pawl portion to stop Oite, the side surface of the boss, with the threaded bore concentric, and wherein forming an arcuate working surface along the longitudinal direction of the screw hole, the tip end of the pawl portion is engaged with the arcuate working surface It is characterized by.
According to a second aspect of the present invention, in the disc brake according to the first aspect, the boss is formed to protrude from a boss main body and a side surface portion of the boss main body, and has a larger diameter than the boss main body. It is characterized by comprising a boss projection having a surface formed thereon.
According to a third aspect of the present invention, in the disc brake according to the first or second aspect, the screw hole of the boss and the arcuate processed surface are processed simultaneously.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a disc brake according to an embodiment of the present invention will be described with reference to FIGS.
1 and 2, reference numeral 5 denotes an iron carrier obtained by casting. The carrier 5 has a plate-like leg portion 6 bent in a substantially U-shape, and one surface of the leg portion 6 (a surface separated from the disk 7; 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 described later with an electrolytic corrosion preventing member 9 having an insulating film formed on the spring steel interposed therebetween.
[0015]
A pair of legs 6 of the carrier 5 are arranged in parallel extending from the legs 6 to the other surface (the surface on the disk 7 side, the left side in FIG. 1; hereinafter referred to as the surface) 5b, and the tip sides are connected to each other. A rod-shaped arm 10 is formed. A protrusion 13 is formed on the arm 10 forming portion in the direction opposite to the arm 10. A flexible boot 12 is mounted between the projection 13 and the caliper 11 that presses the brake pad 15 against the disk 7. A hole 14 extending along the longitudinal direction of the arm 10 is formed in the protrusion 13 and the arm 10. A pair of pins 16 provided on the caliper 11 are movably inserted into the holes 14. The carrier 16 supports the caliper 11 so as to be movable in the axial direction of the disk 7 by inserting the pin 16 in the hole 14 so as to be movable.
[0016]
As shown in FIGS. 2 and 5, a pair of bosses 17 are formed to protrude in the vicinity 6 a of the bent portion of the leg portion 6 on the back surface 5 a 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.
Two arc-shaped processed surfaces 19 that are concentric with the screw hole 18 and extend along the longitudinal direction of the screw hole 18 are formed on the side surface of the boss 17. The diameter of the circle including the two arc-shaped processed surfaces 19 is set to a length B as shown in FIG.
[0017]
The boss 17 has a boss main body 20 having a diameter A as shown in FIG. 6 and a pair of boss protrusions 21 formed so as to be substantially opposed to each other from the side surface of the boss main body 20, as shown in FIG. The distance between the top surface portions 21a of the pair of boss projecting portions 21 including the center of the boss main body 20 is set to be a length C (A <C).
[0018]
The boss 17 shown in FIG. 6 is processed using the drill 1 shown in FIG. 11, and as shown in FIGS. 3 and 4, the screw hole 18, the upper surface portion 17a of the boss 17, and the arc-like processed surface. 19 is formed. The drill 1 includes a holding portion (not shown), a drill body shaft 3 rotatably provided on the holding portion, and a screw hole provided at a center portion of the drill body shaft 3 to form a screw hole 18 of the boss 17. The drill body shaft 3 is formed with an annular groove 22 centering on the screw hole processing shaft 4. In this case, the diameter of the side wall (outside) 22a of the annular groove 22 is set to B (A <B <C).
When the drill 1 is actuated, a screw hole 18 is formed by the screw hole machining shaft 4, the upper surface portion 17 a of the boss 17 is machined by the bottom 22 b of the annular groove 22, and a circular shape is formed by the side wall (outward) 22 a. An arcuate working surface 19 is formed.
[0019]
Further, the upper portion of the surface 5 b of the carrier 5 is formed so as to be higher than the lower portion, and the upper raised portion 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 protrusions 13, the screw holes 18, and the like are formed by being aligned based on the processing reference surface 23.
[0020]
As shown in FIGS. 1 and 7, the electrolytic corrosion preventing member 9 has a ring-shaped electrolytic corrosion preventing member main body 26 that covers the upper surface portion 17 a of the boss 17. As shown in FIGS. 9 and 1, the electric corrosion prevention member main body 26 extends from the outer peripheral portion of the electric corrosion prevention member main body 26 to the surface 5 b side of the leg portion 6 of the carrier 5 and is on one end of the carrier 5. A locking portion 27 having a substantially V-shaped side surface extending over 5c is formed. The distal end portion 27 a of the locking portion 27 is bent and is locked to the processing reference surface 23.
[0021]
Further, as shown in FIGS. 8 and 10, two claw portions 28 having a substantially V-shaped side surface are formed on opposing portions of the outer peripheral portion of the electric corrosion prevention member main body 26. The front end portion 28 a of the first end portion 28 is engaged with the arcuate processing surface 19.
The locking portion 27 and the two claw portions 28 are formed by bending the electrolytic corrosion preventing member body 26. The locking portion 27 and the one claw portion 28 before the bending process are indicated by a two-dot chain 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 a hole 26a formed in the electric corrosion prevention 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.
[0022]
And the assembly | attachment to the carrier 5 of the electrolytic corrosion prevention member 9 is performed as follows. That is, first, the electrolytic corrosion preventing member main body 26 is made to face the upper surface portion 17 a of the boss 17 so that the locking portion 27 of the electrolytic corrosion preventing member 9 is placed on the one end portion 5 c of the carrier 5. Next, the tip end side of the claw portion 28 is locked to the arcuate processed surface 19 while the electric corrosion prevention member main body 26 is pulled downward in FIG.
Thereafter, the end portion 27a of the locking portion 27 is engaged with the processing reference surface 23 by pressing the locking portion 27 forming side portion (upper side in FIG. 1) of the electric corrosion prevention member body 26 against the upper surface portion 17a of the boss 17. . Then, by sandwiching the electric corrosion prevention member main body 26, the locking portion 27, and the claw portion 28, the electric 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.
[0023]
In the disc brake configured 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 28a of the two claw portions 28 are arc-shaped processed surfaces 19. Since the bosses 17 are sandwiched with elastic forces, the electrolytic corrosion preventing member 9 is restricted from moving in the radial direction of the bosses 17. Moreover, since the front end portion 27a of the locking portion 27 engages with the processing reference surface 23 and sandwiches the boss 17 (carrier 5) with the elastic force together with the electrolytic corrosion preventing member main body 26, the axial direction of the electrolytic corrosion preventing member 9 is achieved. Movement is restricted. Thus, the electrolytic corrosion preventing member 9 is restricted from moving in the radial direction of the boss 17 and moving in the axial direction, so that the electrolytic corrosion preventing member 9 can be reliably fixed to the carrier 5.
[0024]
Further, since the claw portion 28 is engaged with the arcuate processed surface 19 concentric with the screw hole 18 and assembled, the hole 26a of the electrolytic corrosion preventing member main body 26 and the screw hole 18 of the boss 17 can be aligned with high accuracy. As described above, the highly accurate alignment is performed, and the electrolytic corrosion preventing member 9 is securely fixed to the carrier 5 as described above, so that the electrolytic corrosion preventing member main body 26 is fixed to the screw hole 18 of the boss 17. Since the hole 26a can be prevented from shifting, the bolt 29 can be prevented from coming into contact with the electrolytic corrosion preventing member main body 26 during the assembly work of the bolt 29, and can be assembled smoothly.
[0025]
Thereafter, the carrier 5 with the electric corrosion prevention member 9 temporarily fixed as described above is positioned by screw screw hole 18 being aligned with hole 8a of knuckle 8, and screw 29 is screwed into screw hole 18. The carrier 5 is fixed to the knuckle 8 with the prevention member 9 assembled.
[0026]
In this embodiment, since the processing of the arc-shaped processed surface 19 is performed simultaneously with the processing of the screw hole 18 of the boss 17, a processed surface for temporarily fixing the electrolytic corrosion preventing member 9 to the carrier 5 is formed separately. The processing man-hours and processing time can be shortened by that amount.
Further, since the arcuate processed surface 19 is formed by machining, the dimensional tolerance is smaller than that in the case of a casting (the dimensional tolerance in the case of a casting is ± 1, whereas the dimensional tolerance in the case of machining). Can be assembled with a stable assembling force with less variation in the tightening allowance of the distal end portion 27a of the locking portion 27.
[0027]
Further, in the above-described prior art, the one end of the carrier is straddled by the engaging portion of the electrolytic corrosion prevention member, and the other end of the center of the three positioning claws is opposed to the one end of the carrier. The electric corrosion prevention member is fixed to the carrier so as to straddle the portion, but in contrast to this, in the above embodiment, the central positioning claw portion is abolished and the electric corrosion prevention member 9 Since reliable fixing is achieved, interference with surrounding parts can be suppressed and the degree of freedom in arrangement can be increased by eliminating the central positioning claw.
[0028]
In the above embodiment, the case where the two arc-shaped machining surfaces 19 and the two locking portions 27 are provided is taken as an example, but one arc-shaped machining surface and 1 or 3 latched on the arc-shaped machining surface are used. You may provide the above latching | locking part. Moreover, you may comprise so that three or more arc-shaped processed surfaces and three or more latching parts latched by this arc-shaped processed surface may be provided.
[0029]
【The invention's effect】
According to the first to third aspects of the present invention, since the arcuate processed surface 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). On the other hand, the dimensional tolerance in the case of machining can be ± 0.25.), Which reduces the variation in the tightening allowance of the front end of the locking portion and allows the assembly with a stable assembling force. it can.
In addition, the base end side portion of the locking portion is locked to one side end portion of the carrier, and the tip end portion of the claw portion is locked to the arc-shaped processing surface, and sandwiches the boss with each elastic force, The electric corrosion prevention member is restricted from moving in the radial direction of the boss, and the tip of the locking portion engages with the processing reference surface, and the electric corrosion prevention member body and the boss (carrier) are clamped with elasticity. Thus, since the movement of the electrolytic corrosion preventing member in the axial direction is restricted, the electrolytic corrosion preventing member can be reliably fixed to the carrier.
[0030]
In addition, the claw is locked and assembled to the arc-shaped machining surface concentric with the screw hole, so that the hole in the electrolytic corrosion prevention member body and the screw hole in the boss can be aligned with high accuracy. As described above, the highly accurate positioning is performed, and the electrolytic corrosion preventing member is securely fixed to the carrier as described above, so that the hole of the electrolytic corrosion preventing member main body is displaced with respect to the screw hole of the boss. Since it can suppress, at the time of the assembly | attachment operation | work of a volt | bolt, it is avoided that a volt | bolt contacts the electric corrosion prevention member main body, and can assemble | attach smoothly.
According to the invention of claim 3, since the screw hole of the boss and the arc-shaped processed surface are processed at the same time, it is not necessary to separately form a processed surface for temporarily fixing the electrolytic corrosion preventing member to the carrier. Therefore, the processing man-hours and the processing time can be shortened accordingly.
[Brief description of the 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.
3 is a cross-sectional view taken along line XX in FIG.
4 is an enlarged view showing a boss of the carrier of FIG. 2. FIG.
FIG. 5 is a view taken along the arrow T in FIG. 2;
6 is a view of a cast state before processing of the carrier of FIG. 4;
7 is a perspective view showing an electrolytic corrosion preventing member used for the disc brake of FIG. 1. FIG.
FIG. 8 is a plan view of the electric corrosion prevention member.
9 is a cross-sectional view taken along the line YY in FIG.
10 is a cross-sectional view taken along arrow ZZ in FIG.
11 is a cross-sectional view showing a drill for forming a screw hole of the disc brake of FIG. 1; FIG.
FIG. 12 is a cross-sectional view showing a screw hole forming drill used in an example of a conventional disc brake.
[Explanation of symbols]
5 Carrier 7 Disk 8 Knuckle 9 Electric corrosion prevention member 11 Caliper 17 Boss 18 Screw hole 19 Arc-shaped machining surface 23 Processing reference surface 26 Electric corrosion prevention member main body 27 Locking portion 28 Claw portion

Claims (3)

A convex boss formed with a screw hole is provided on the surface side of the carrier that supports the caliper so as to be movable in the axial direction of the disk, and is separated from the disk.
An electrolytic corrosion prevention member is interposed between the boss and the non-rotating part of the vehicle, and the carrier is attached to the non-rotating part of the vehicle by screwing a bolt into the screw hole .
The electrolytic corrosion preventing member includes a substantially ring-shaped electrolytic corrosion preventing member body interposed between the boss and the non-rotating portion of the vehicle, and one side of the carrier from the outer peripheral portion of the electrolytic corrosion preventing member body. A locking portion that is bent and extends so as to straddle the end portion, a front end side is bent, and is locked to a processing reference surface formed on a surface portion on the disk side of the carrier, and an outer peripheral portion of the electrolytic corrosion prevention member main body In a disc brake having a claw portion which is bent and formed and has a claw portion which engages with the boss on the tip side ,
An arc-shaped machining surface that is concentric with the screw hole and extends along the longitudinal direction of the screw hole is formed on the side surface of the boss, and the tip side of the claw portion is locked to the arc-shaped machining surface. Disc brake to play. The boss includes a boss main body and a boss projecting portion that protrudes from a side surface of the boss main body and has an arcuate processed surface having a larger diameter than the boss main body. Item 1. The disc brake according to item 1. 3. The disc brake according to claim 1, wherein the screw hole of the boss and the arcuate machining surface are machined simultaneously.

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