JP4841895B2 - Pin connection structure - Google Patents

Description

  The present invention relates to a pin coupling structure of a floating brake disc used for braking a motorcycle, for example.

  In the floating type brake disc, the braking rotor and the hub are coupled to each other through a predetermined gap so that the thermal expansion of the braking rotor due to heat generation is provided between the braking rotor and the hub during braking by the brake operation. Absorbs in the gap and eliminates problems such as deformation of the braking rotor itself.

  In this case, the hub is concentrically arranged inside the brake rotor, and the insertion piece is formed by abutting the projecting piece formed on the inner peripheral surface of the brake rotor and the semicircular coupling recess provided on the outer peripheral surface of the hub. In this insertion hole, a coupling pin having a flange portion that abuts against the braking rotor and the hub in the axial direction is inserted, and one end of the cylindrical columnar portion of the coupling pin extending in the insertion direction is crimped to expand the diameter, The braking rotor and the hub are coupled.

  In order to reduce the weight of the disc brake, for example, a hollow pin made of an aluminum alloy is used as the coupling pin, and an anti-corrosion surface treatment layer such as anodized is formed on the entire surface in order to achieve corrosion resistance. It has been. When this hollow pin is used, it is necessary to prevent the surface treatment layer from being broken and the background from appearing when the end portion of the coupling pin is caulked.

From this, it is known that a chamfered portion having a convex arc shape is provided on one peripheral surface of the center hole of the hollow pin formed with the surface treatment layer, and the tip of the columnar portion of the hollow pin is crimped to increase the diameter. (For example, Patent Document 1).
Japanese Patent Laid-Open No. 2001-187910 (for example, refer to the description of claims)

  In the above hollow pin, since there is no bent portion at one end of the columnar portion which is a caulking portion, the pressure is dispersed during caulking, and the surface treatment layer can be prevented from being damaged, but the portion excluding the caulking portion of the central hole Is formed in a straight line substantially perpendicular to the flange part, that is, the thickness of the hollow cylindrical columnar part is made substantially constant.

  For this reason, increase the number of hollow pins used to receive axial and torsional loads during braking without increasing the wall thickness of the columnar parts (without increasing the weight of the hollow pins themselves). In other words, it is necessary to distribute the load by increasing the number of coupling points between the braking rotor and the hub by the hollow pins, and to reduce the load per hollow pin. In this case, the number of coupling pins used increases, resulting in an increase in the total weight of the hollow pins, and because there are many coupling points, the shapes of the braking rotor and hub are restricted, and the brake disc cannot be effectively reduced in weight. .

  Therefore, an object of the present invention is to provide a pin coupling structure that can effectively reduce the weight of a brake disk while having sufficient strength.

In order to solve the above-described problems, the present invention has a hub disposed concentrically inside the braking rotor, and a semicircular coupling recess provided on each of the inner circumferential surface of the braking rotor and the outer circumferential surface of the hub. An insertion hole is formed, a hollow pin having a flange portion that abuts against the braking rotor and the hub in the axial direction is inserted into the insertion hole, and one end of a columnar portion of the hollow pin extending in the insertion direction is caulked, and the braking rotor and the hub In the pin connection structure in which the flange portions of the columnar portions are formed with a thickness over a predetermined length, the length of the thick portion is the both sides of the punched braking rotor, In the state where the hollow pin is inserted into the insertion hole so that the flange portion comes into contact with one surface further away from the shearing surface generated by the punching process, the end portion on the opposite side to the flange portion of the thick portion is the shearing surface. An end of the one surface side; The center hole of the hollow pin is enlarged so as to expand toward the end of the columnar part from the thick part, and at least one end peripheral surface of the center hole is a convex curved surface. It is characterized by.

  According to the present invention, for example, when a braking rotor is sandwiched between brake pads set on a caliper to exert a braking force, axial and torsional loads are applied from the braking rotor to the columnar portion of the hollow pin. Since there is a thick portion at the location where the is added, the strength per hollow pin is improved compared to the conventional one, and it has sufficient strength against the load in the torsional direction. For this reason, the number of hollow pins used can be reduced, that is, the number of locations where the braking rotor and the hub are connected can be reduced.

  On the other hand, since the diameter from the thick part to one end of the columnar part is expanded, the volume of the columnar part is reduced, and the increase in the weight of the hollow pin per piece due to the thickening of a part of the columnar part can be minimized. . For this reason, the total weight of the connecting pins to be used can be reduced and the number of connecting portions can be reduced, so that the area of the brake rotor and hub can be reduced. Weight reduction can be achieved.

  In addition, since the thickness of one end of the columnar portion is small, one end of the columnar portion can be caulked with a small load, and at least one peripheral surface of the center hole is distributed so that the pressure is dispersed when caulking Since the surface is a convex curved surface, the surface treatment layer is not damaged during caulking.

  In this case, if the central hole is connected from the thick part to one end of the columnar part with a convex curved surface, the part bent when the diameter of the central hole is expanded toward the one end of the columnar part. I do not have to.

  By connecting the center hole from the thick part to the other end of the columnar part with a convex curved surface that expands toward the end, the weight of each hollow pin can be further reduced without reducing the strength of the hollow pin. .

  In order to further reduce the weight of each hollow pin, it is preferable that the inner peripheral surface of the thick portion is substantially perpendicular to the flange portion.

  By the way, when connecting a braking rotor and a hub, a braking rotor is used without using both front and back. For this reason, it is preferable that the outer peripheral surface of the thick portion is substantially perpendicular to the flange portion so as not to depend on the mounting direction of the coupling pin to the braking rotor.

  If the thickness of the thick portion is set larger than the length of the flange portion in the radial direction, a load in the torsional direction larger than the axial load can be received efficiently.

  Moreover, it is preferable to provide a groove portion for preventing the brake rotor and the hub from being biased at the boundary between the columnar portion and the flange portion.

  The hollow pin is made of, for example, an aluminum alloy provided with a corrosion-resistant surface treatment layer.

  As described above, the pin coupling structure of the present invention has an effect of effectively reducing the weight of the brake disk while having sufficient strength.

  Referring to FIG. 1, reference numeral 1 denotes a floating brake disc having a pin coupling structure according to the present invention. The brake disk 1 includes a braking rotor 2 and a hub 3 and is coupled to a floating state by a coupling pin 4.

  The brake rotor 2 is made of a metal material having wear resistance such as an aluminum alloy, and is formed by punching using a disk work as a starting material. In this case, the braking rotor 2 is formed at a predetermined interval on the inner peripheral edge portion of the rotor portion 21 so as to match the number of the rotor portion 21 formed in an annular shape with a flat plate and the shaft portion of the hub 3 described later. It is comprised from the protrusion piece 22 which protrudes toward a radial inside.

  A semicircular coupling recess 23 is formed at the tip of each protruding piece 22, and a circular through-hole having the same diameter is provided on the axial surface of the rotor portion 21, for example, in order to improve braking performance or reduce weight. A plurality of 24 are formed. And, it is sandwiched between brake pads set on the caliper during brake operation, and exhibits braking force.

  The hub 3 is formed of a metal material that can withstand a load during braking, such as an aluminum alloy, and is a flat base plate 31 provided with a central opening 31a that can be mounted on an axle (not shown), and a radius from the base portion 31. The shaft portion 32 extends outward in the direction, and the beam portion 33 that linearly connects the shaft portions 32 in the vicinity of the tip of the shaft portion 32.

  In this case, a disk work having a base 31 is used as a starting material, and substantially trapezoidal through holes are punched on the same circumference at equal intervals on the surface in the axial direction. The hub 3 is formed by punching the outer peripheral edge of the workpiece so as to be formed, and a semicircular coupling recess 34 is formed at the tip of each shaft portion 32.

  The hub 3 is concentrically disposed inside the braking rotor 2, and the semicircular coupling recesses 23 and 34 provided on the projecting piece 22 of the braking rotor 2 and the shaft portion 32 of the hub 3 are abutted to each other to have a substantially circular cross section. In this insertion hole, a coupling pin 4 to be described later is inserted, and washers 5a, 5b and a disc spring 6 are inserted into one end protruding to the opposite side, and a roller caulking machine (not shown) is inserted. The brake rotor 2 and the hub 3 are coupled in a floating state by caulking one end thereof to increase the diameter.

  As shown in FIGS. 2 and 3, as the coupling pin 4, a hollow pin made of an aluminum alloy having a center hole 41 is used in order to reduce the weight of the brake disc 1. The flange portion 42 is in contact with the hub 3 in the axial direction, and the columnar portion 43 extends from the flange portion 42 toward one side. Further, in order to improve the corrosion resistance, the surface of the hollow pin 4 is covered with a known corrosion-resistant surface treatment layer such as anodized (oxide film).

  By the way, when the braking rotor 2 is sandwiched and the braking force is exerted, the hollow pin 4 is applied with a load in the axial direction or torsional direction from the braking rotor 2. Distributing the load by increasing the number of joints between the braking rotor 2 and the hub 3 by the hollow pins 4 not only reduces the weight of the hollow pins 4 but also reduces the weight. 3 is restricted, and the weight of the brake disk 1 cannot be effectively reduced.

  In the present embodiment, when the brake rotor 2 is punched, a shearing surface that is perpendicular to the axial surface of the brake rotor 2 and is linear in a cross-sectional view (a region indicated by a length l in FIG. 3). The part of the columnar part 43 that abuts a part of the part is defined as a thick part 43a. In this case, the outer peripheral surface of the columnar portion 43 including the thick portion 43a has an outer shape that substantially matches the diameter of the insertion hole formed by the coupling recesses 23 and 34, and is formed at a substantially right angle to the flange portion 42. Yes. Further, the inner peripheral surface of the thick portion 43 a in the center hole 41 is formed substantially perpendicular to the flange portion 42.

  When the brake rotor 2 and the hub 3 are assembled, the brake rotor 2 is used without using the front and back sides of the brake rotor 2, so that it does not depend on the mounting direction of the hollow pin 4 to the brake rotor 2 and is formed by the coupling recesses 23 and 34. When the hollow pin 4 is inserted into the inserted hole, the thick portion 43a is always present in a part of the shear surface, and the thick portion 43a has a minimum length so that the length of the thick portion 43a is minimized. The length of 43a in the insertion direction is set.

  The thickness t1 of the thick portion is set to be larger than the radial length d1 of the flange portion 42 so as to efficiently receive the torsional direction load larger than the axial load during braking. Thereby, the strength per one hollow pin 4 is improved as compared with the conventional one, and it has sufficient strength against the load in the torsional direction. As a result, the number of hollow pins 4 used can be reduced. Less.

  Further, the diameter of the center hole 41 of the hollow pin 4 is expanded from the thick portion 43a toward one end of the columnar portion 43 (in a taper shape in a cross-sectional view), and one end circumferential surface of the center hole 41 is entirely formed. A convex curved surface 43b was formed. As a result, an increase in the weight of each hollow pin 4 due to the thickening of a part of the columnar part 43 can be minimized, and the thickness t2 at one end of the columnar part 43 is reduced (in this case, t2 Can be smaller than d1), one end of the columnar portion 43 can be caulked with a small load, and the surface treatment layer is not damaged during caulking.

  On the other hand, the thick hole 43a in the center hole 41 is connected to the other end of the columnar portion 43 by a convex curved surface 44 that widens toward the end. Thereby, the weight of the hollow pin 4 per piece can be further reduced without preventing stress concentration due to the absence of the bent portion and reducing the strength of the hollow pin 4. In this case, the distance d2 from the boundary surface between the flange portion 42 and the columnar portion 43 to the curved surface 44 is set to be larger than the length d1 of the flange portion 42.

  Further, a groove 45 is provided at the boundary between the flange portion 42 and the columnar portion 43 so as to prevent the braking rotor 2 and the hub 3 from being biased. In this case, a concave arcuate surface is formed on the inner peripheral end side of the groove 45 to prevent stress concentration.

  In addition, in this Embodiment, although what was diameter-expanded toward the one end of the columnar part 43 from the thick part 43a was demonstrated, it extends from the thick part 43a to the end of the columnar part 43 over the whole. It may be tied with a convex curved surface. In this case, the center hole 41 cannot be bent when expanding from the thick portion 43a toward one end of the columnar portion 43, and the thickness t2 at one end of the columnar portion is further reduced. The amount of diameter expansion can be increased, and the hollow pin 4 itself can be further reduced in weight.

  In the present embodiment, the hollow pin made of an aluminum alloy has been described. However, any material can be used as long as the brake disk 1 can be reduced in weight.

The perspective view explaining the coupling | bonding (assembly) of the floating type brake disc of this invention. Sectional drawing explaining the pin for a coupling | bonding. (A) And (b) is sectional drawing which shows the state which the brake rotor and the hub couple | bonded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Floating type brake disk 2 Brake rotor 3 Hub 4 Connecting pin 41 Center hole 42 Flange part 43 Columnar part 43a Thick part

Claims (8)

A hub is concentrically arranged inside the brake rotor, and an insertion hole is formed by abutting the semicircular coupling recesses provided on the inner peripheral surface of the brake rotor and the outer peripheral surface of the hub, respectively. In a pin coupling structure in which a hollow pin having a flange portion that abuts the rotor and the hub in the axial direction is inserted, and one end of a columnar portion of the hollow pin extending in the insertion direction is caulked to couple the braking rotor and the hub.
The portion near the flange portion of the columnar portion is formed to be thick over a predetermined length. In a state where the hollow pin is inserted into the insertion hole so that the flange portion comes into contact with one of the separated surfaces, the end portion on the side opposite to the flange portion at the thick portion is the end portion on the one surface side of the shear surface And is set to overlap in the axial direction,
A pin coupling structure characterized in that the center hole of the hollow pin is expanded from the thick part toward one end of the columnar part, and at least one peripheral surface of the center hole is a convex curved surface.
The pin coupling structure according to claim 1, wherein the central hole is connected with a convex curved surface from a thick portion to one end of the columnar portion. 3. The pin coupling structure according to claim 1, wherein a portion of the center hole connected from a thick portion to the other end of the columnar portion is connected with a convex curved surface that expands toward the end. The pin coupling structure according to any one of claims 1 to 3, wherein an inner peripheral surface of the thick portion is substantially perpendicular to the flange portion. The pin coupling structure according to any one of claims 1 to 4, wherein an outer peripheral surface of the thick portion is substantially perpendicular to the flange portion. The pin coupling structure according to any one of claims 1 to 5, wherein a thickness of the thick portion is set larger than a length in a radial direction of the flange portion. The pin coupling structure according to any one of claims 1 to 6, wherein a groove portion is provided at a boundary between the columnar portion and the flange portion to prevent the brake rotor and the hub from being unevenly contacted. 8. The pin coupling structure according to claim 1, wherein the hollow pin is made of an aluminum alloy provided with a corrosion-resistant surface treatment layer.

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