JP2004169738A - Disc brake rotor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain quality having a desired dimension accuracy and reduce in cost. <P>SOLUTION: This manufacturing method of the disc brake rotor has a press process in which an outer rotor 2' and an inner rotor 3' are integrally formed with a coupling part 11 extending in a peripheral direction interposed therebetween while fit parts 2b and 3b of the respective outer rotor 2' and inner rotor 3' are different in phase in the peripheral direction. In this method, after the press process, a sliding part 2c of at least the outer rotor 2' is subject to a surface hardening by an induction hardening, and thereafter, the coupling part 11 is divided by a press working, whereby an annular gap in the fit parts 2b and 3b can be set to a wide range. Accordingly, a degree of freedom in design is enhanced, and thermal deformation due to hardening is absorbed by plastic deformation of the coupling part 11. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a disk brake rotor, and more particularly to a floating type disk brake rotor used for a braking device of a motorcycle and a method of manufacturing the same.
[0002]
[Prior art]
Conventionally, in a disk brake rotor of a motorcycle, the pad sliding portion thermally expands due to heat generated during braking, and distortion such as warpage or undulation is generated in the sliding portion, which induces an uneven contact of the brake pad, and This leads to problems such as uneven wear of the steel and a decrease in braking force. In order to improve this drawback, a floating type disk brake rotor as shown in FIGS. 6 and 7 has been known.
[0003]
FIG. 6 is a plan view showing a conventional floating type disk brake rotor, FIG. 7A is an enlarged sectional view of a main part of FIG. 6, and FIG. 6B is a sectional view taken along line VII-VII of FIG. .
[0004]
The disc brake rotor 51 includes an outer rotor 52 having a disk-shaped sliding portion 52a, and an inner rotor having a plurality of wheel mounting holes 58, which is internally fitted to the outer rotor 52 via a predetermined annular clearance δ. 53. A fitting portion is provided between these two rotors 52 and 53. Further, an annular clearance δ is formed between the two rotors 52 and 53 in the fitting portion. A caulking pin 56 is loosely fitted into each of a plurality of pin holes 57 having centers on the circumference of the annular clearance δ, and the caulking pin 56 is connected to the outer rotor 52 via a disc spring 54 and a washer 55. It is crimped to the inner rotor 53. The caulking portion 56a regulates the relative movement of the two rotors 52 and 53 in the axial direction. Here, a clearance e is provided between the inner diameter of the pin hole 57 and the caulking pin 56, and the clearance e can absorb distortion of the outer rotor 52 due to heat generated during braking.
[0005]
Further, this kind of disc brake rotor 1 is manufactured through a process as shown in FIG. That is, the process includes a pressing process of (a), a quenching process of (b), a machining process of (c), a cutting process of (d), and an assembling process of (e).
[0006]
In the pressing step (a), the inside and outside diameters and the portions corresponding to the recesses 52b and 53a and the drainage hole 52d of the sliding portion 52a are punched from the steel strip, and the sliding portion 52a indicated by hatching in (b) is subjected to high-frequency induction heating. Quench and subject to surface hardening. Thereafter, in the machining step (c), the inner and outer diameters are finished to a predetermined size using a lathe or the like, deburring is performed, a wheel mounting hole 58 is formed by a drill, and the surface is further cut by grinding or the like. In a dividing step shown in the following (d), the outer rotor 52 and the inner rotor 53 are divided by punching out the annular clearance δ and the pin hole 57 at a portion corresponding to the fitting portion. Finally, in the assembling step shown in (e), the caulking pin 56 is loosely fitted into the punched pin hole 57, and the caulking pin 56 is connected to the outer rotor 52 and the inner rotor 53 via the disc spring 54 and the washer 55. Swage and fix both together.
[0007]
In the above-described manufacturing process, the outer rotor 52 and the inner rotor 53 are separated from each other in the process immediately before the assembling process, so that the processing process, particularly the machining process, can be simplified, and the cost can be reduced. (See Patent Document 1).
[0008]
[Patent Document 1]
JP-A-2002-227891 (pages 3, 4; FIGS. 1, 2)
[0009]
[Problems to be solved by the invention]
Such a conventional floating type disk brake rotor 51 has the contradictory functions of strength and light weight, can minimize thermal deformation during braking, minimize the number of steps, and perform machining. The cost can be reduced by simplifying the process. However, on the other hand, internal stress is generated at the quenching boundary by the induction quenching, and after the outer rotor 52 and the inner rotor 53 are separated from each other, the outer rotor 52 has a bowl-shaped sled whose outer diameter side is inclined to one side. At the same time, the inner rotor 53 has a tendency to generate torsional surface runout along the circumferential direction.
[0010]
If such warpage or surface run-out is corrected by machining or the like, the cost will rise, which is not preferable. Therefore, there has been a demand for a disc brake rotor and a method of manufacturing the same that satisfy the conflicting demands of maintaining quality with desired dimensional accuracy and reducing costs.
[0011]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a disk brake rotor which maintains quality having desired dimensional accuracy and reduces cost, and a method of manufacturing the same.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 of the present invention provides an outer having a sliding portion on an outer peripheral portion and a plurality of fitting portions projecting radially inward on an inner peripheral portion. A rotor, corresponding to a fitting portion of the outer rotor, having a plurality of fitting portions protruding radially outward on an outer peripheral portion thereof, and an inner rotor having a plurality of wheel mounting holes on an inner peripheral portion, A caulking pin fitted into a pin hole formed by a substantially semicircular recess formed in each of the fitting portions, and caulking the caulking pin to transmit torque between the outer rotor and the inner rotor. In a floating type disk brake rotor which is integrally fixed as much as possible, a configuration is employed in which one side surface of the fitting portion between the outer rotor and the inner rotor has a sheared surface which is divided after quenching.
[0013]
As described above, since the quenching is performed in a state where the one side surface of the fitting portion of the outer rotor and the inner rotor is connected, the heat distortion due to the quenching can be absorbed by the plastic deformation of the connecting portion, and the desired dimensional accuracy is obtained. It is possible to provide a disc brake rotor that maintains quality and reduces costs.
[0014]
The invention according to claim 2 of the present invention provides an outer rotor having a sliding portion on an outer peripheral portion and a plurality of fitting portions projecting inward in a radial direction on an inner peripheral portion; Corresponding to the fitting portion of the rotor, an outer rotor has a plurality of fitting portions protruding radially outward, and an inner rotor having a plurality of wheel mounting holes in an inner circumferential portion, and A caulking pin fitted into a pin hole formed by a substantially semicircular recess formed respectively, and caulking the caulking pin to integrally fix the outer rotor and the inner rotor so that torque can be transmitted. The fitting method of the outer rotor and the inner rotor is different in phase in the circumferential direction, and the outer rotor and the inner rotor are integrated through a connecting portion extending in the circumferential direction. To Characterized in that it comprises a pressing step of forming.
[0015]
According to this method, the fitting portions of the outer rotor and the inner rotor have different phases in the circumferential direction, and the outer rotor and the inner rotor are integrally formed in the pressing step via the connecting portion extending in the circumferential direction. Therefore, the diameters of the two rotors can be set appropriately. Therefore, the annular clearance in the fitting portion between the two can be appropriately set in a wide range, and the degree of design freedom is increased.
[0016]
Further, as in the invention according to claim 3, after the pressing step, at least a sliding portion of the outer rotor is subjected to a surface hardening treatment by induction hardening, and thereafter, the connecting portion is separated by press working. Therefore, it is possible to provide a disk brake rotor that can absorb the thermal strain due to the plastic deformation of the connecting portion, maintain the quality having the desired dimensional accuracy, and reduce the cost.
[0017]
Preferably, as in the invention according to claim 4, if the connecting portion is divided by pressing and the recess of the fitting portion is formed by pressing, the number of processing steps can be further reduced, and the cost is reduced. Can be achieved.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B show an embodiment of a disk brake rotor according to the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a sectional view.
[0019]
In FIG. 1, an inner rotor 3 of a disc brake rotor 1 is fitted to an inner diameter of an outer rotor 2 via a predetermined annular clearance δ. Both are caulked by a hollow caulking pin 6 via a disc spring 4 and a washer 5. 2 (a) and 2 (b) are enlarged cross-sectional views of a main part of the caulked portion, where (a) shows a state before caulking and (b) shows a state after caulking. (C) is a sectional view taken along line II-II in (b).
[0020]
A plurality of fitting portions 2b of the outer rotor 2 are formed on the inner peripheral portion so as to protrude radially inward. On the other hand, a plurality of fitting portions 3b of the inner rotor 3 correspond to the fitting portions 2b of the outer rotor 2, and are formed on the outer peripheral portion so as to protrude radially outward. Semicircular recesses 2a, 3a are formed in these fitting portions 2b, 3b, respectively, to form pin holes 7. The pin hole 7 has a center on an annular clearance δ provided in the fitting portions 2b, 3b of the two rotors 2, 3. The caulking pin 6 is loosely fitted into the plurality of pin holes 7, and the caulking pin 6 is caulked to the outer rotor 2 and the inner rotor 3 via the disc spring 4 and the washer 5. The outer rotor 2 and the inner rotor 3 are integrally fixed by the caulking portion 6a and the flange portion 6b of the caulking pin 6 so that torque can be transmitted in the circumferential direction and relative movement in the axial direction is restricted. Will be. Here, a clearance e is provided between the inner diameter of the pin hole 7 and the caulking pin 6. Normally, during braking, a brake pad (not shown) slides on the sliding portion 2c of the outer rotor 2 to generate heat, and the sliding portion 2c thermally expands to generate distortion such as warpage and undulation. The distortion of the outer rotor 2 can be absorbed as much as possible by the annular clearance δ described above.
[0021]
A washer 5 is provided on the inner diameter side of the washer 5 so that the disc spring 4 mounted on the caulking pin 6 is accurately centered and caulked without being displaced. In addition, before fitting the disc spring 4 and the washer 5 to the caulking pin 6, respectively, the disc spring 4 and the washer 5 may be integrally fixed by caulking or the like before fitting to the caulking pin 6. good. In the present embodiment, the form in which the disc spring 4 and the washer 5 are fitted to the caulking pin 6 and the caulking pin 6 is caulked is exemplified. However, the present invention is not limited to this, and the washer 5 is simply omitted. The outer spring 2 and the inner rotor 3 may be integrally fixed by disposing the disc spring 4 on the flange portion 6b side of the caulking pin 6 and plastically deforming the opposite flange side of the caulking pin 6 radially outward. .
[0022]
In FIG. 1A, a plurality of drainage holes 2d are formed in the sliding portion 2c of the outer rotor 2 in the circumferential direction to prevent wear powder and moisture from staying in the sliding portion 2c. In particular, muddy water can be effectively prevented from clogging the sliding portion 2c during off-road. Further, by forming a plurality of the drain holes 2d, the air cooling effect of the sliding portion 2c is further enhanced, and the outer rotor 2 is reduced in weight together with the plurality of recesses 2e formed in the inner diameter portion of the outer rotor 2. ing. The shape of the drain hole 2d is not limited to a circular hole, but may be a slit shape.
[0023]
In the inner peripheral portion of the inner rotor 3, a plurality of mounting holes 8 for mounting to wheels (not shown) are formed in a circumferentially equidistant manner. In addition, a recess 3c is formed on the outer peripheral portion of the inner rotor 3 so as to face the recess 2e of the outer rotor 2, thereby reducing the weight of the inner rotor 3.
[0024]
Next, a method of manufacturing the above-described disc brake rotor 1 will be described in detail with reference to FIGS. 3 and 4 are explanatory views showing a part of the pressing process. The pressing process basically consists of four processes: a process of punching a disc-shaped material from a steel strip, a process of punching a drain hole in this material, a process of punching a dent, and a process of punching an inner diameter portion. .
[0025]
After punching the blank 9 from a strip of martensitic stainless steel such as SUS410 into a disc shape, as shown in FIG. 3, a plurality of drainage holes 2d are formed in the outer peripheral portion corresponding to the sliding portion 2c. I have. When the material 9 is punched into a disk shape, the outer diameter is set to a predetermined value in consideration of the amount of thermal expansion during quenching, which is the next step. In the center of the material 9, a pair of a center hole 9a for centering the material in a later step and a small hole 9b for determining the phase of the material are formed. In this step, three rows of drainage holes 2d are formed in each row in the circumferential direction, and the rows are alternately formed in a zigzag pattern so that the intervals between the drainage holes 2d are substantially equal. In the present embodiment, the water drainage holes 2d are formed by dividing the circumference into eight equal parts, that is, by 45 ° indexing. However, the present invention is not limited to this, and all the water drainage holes 2d are formed by one pressing step. They may be formed at once.
[0026]
FIG. 4 shows a step of punching through holes 10 (shown by hatching in the figure) corresponding to the recess 2 e of the outer rotor 2 and the recess 3 c of the inner rotor 3. Here, portions 2 ′ and 3 ′ corresponding to the outer rotor 2 and the inner rotor 3 are still connected by the connecting portion 11. Thereafter, the press process is completed by punching the inner diameter of the material 9 '.
[0027]
Here, the fitting portions 2b ', 3b' of the portions 2 ', 3' corresponding to the outer rotor 2 and the inner rotor 3 have different phases in the circumferential direction, and these outer rotors are connected via the connecting portion 11 extending in the circumferential direction. The corresponding portion 2 'and the inner rotor corresponding portion 3' are integrally formed. Therefore, the diameter of the fitting portion between the two rotors 2, 3 can be appropriately set without being restricted by the size, the thickness of the material, and the like, and the annular clearance δ at the fitting portions 2b ', 3b' of both rotors. Can be set in a wide range and appropriately. As a result, the optimum annular clearance δ can be set in any specification, and the degree of freedom in design increases.
[0028]
After the above-described pressing step, at least the sliding portion 2c of the outer rotor 2 is quenched and hardened by high-frequency induction heating to form a hardened layer on the surface with a surface hardness of 30 to 40 HRC, preferably 32 to 38 HRC. Further, after this, the surface is subjected to rust prevention treatment such as cationic electrodeposition coating. Here, after the material is heated to approximately 1000 ° C. by high-frequency induction heating, the sliding portion 2c of the outer rotor 2 is sandwiched between a pair of cooling plates (not shown) to quench while suppressing deformation of the quenching portion. The so-called press quench is performed. This cooling plate is made of hot die steel, and circulates cooling water through a water passage formed therein to increase cooling efficiency.
[0029]
In the next machining step, the inner and outer diameters are finished to predetermined dimensions using a lathe or the like, and the corners of the inner and outer diameters are deburred. The wheel mounting hole 8 is formed by a drill or the like, and the surface is further cut into an iris shape by grinding or the like. Here, the wheel mounting hole 8 is formed by machining after quenching. However, the present invention is not limited to this. The wheel mounting hole 8 may be formed in advance by a pressing process similarly to the drainage hole 2d.
[0030]
Next, a dividing step of dividing the outer rotor 2 and the inner rotor 3 will be described with reference to FIG. The machined material 9 ″ is formed in a state where portions 2 ′ and 3 ′ corresponding to the outer rotor 2 and the inner rotor 3 are connected by a connecting portion 11. The connecting portion 11 of the material 9 ″ is Punching is performed to form the recess 2a of the outer rotor 2 and the recess 3a of the inner rotor 3 (shown by broken lines in the figure). Unlike the related art, the outer rotor 2 and the inner rotor 3 are integrally connected by punching out the recesses 2e and 3c in such a manner that the phases of the recesses 2a and 3a are shifted from each other, thereby forming the connecting portion 11 extending in the circumferential direction. Can be secured. Therefore, the heat treatment and the mechanical processing can be performed in a state where the outer rotor 2 and the inner rotor 3 are integrated, and the number of steps can be minimized to reduce the cost.
[0031]
Further, the internal stress is generated by the induction hardening, and after the outer rotor 2 and the inner rotor 3 are separated from each other, the strain caused by releasing the stress can be absorbed by the plastic deformation of the connecting portion 11. Since the connecting portion 11 is finally punched out by press working, after the division, the outer rotor 2 and the inner rotor 3 are not distorted as in the prior art, and a low-cost and high-precision disk brake rotor is provided. Can be provided.
[0032]
The shape of the connecting portion 11 is not limited to this, and the fitting portion 2b of the outer rotor 2 and the fitting portion 3b of the inner rotor 3 have different phases in the circumferential direction, and connect these fitting portions 2b, 3b. It is only necessary to have a beam shape extending in the circumferential direction. The width of the beam portion in the connecting portion 11 is appropriately set according to the thickness of the material, the workability of the press, the rigidity after the press working, the annular clearance δ of the fitting portions 2b, 3b, and the like. It is preferable that the thermal strain is absorbed by the plastic deformation of this part and the part to be divided by the press working is a part whose surface is hardened by quenching.
[0033]
After separating the outer rotor 2 and the inner rotor 3, the pin holes 7 are formed by the recesses 2a, 3a formed in the fitting portions 2b, 3b by adjusting the circumferential phases of the fitting portions 2b, 3b. can do. As described above, the caulking pin 6 is fitted into the pin hole 7, and the outer rotor 2 and the inner rotor 3 are integrally fixed to complete the assembly.
[0034]
As described above, the embodiments of the present invention have been described. However, the present invention is not limited to these embodiments at all, but is merely an example, and may be variously modified without departing from the gist of the present invention. The scope of the present invention is, of course, indicated by the appended claims, and further includes the equivalent meanings described in the appended claims and all modifications within the scope. Including.
[0035]
【The invention's effect】
As described in detail above, the floating type disk brake rotor according to the present invention has an outer rotor having a sliding portion on an outer peripheral portion and a plurality of fitting portions protruding radially inward on an inner peripheral portion. And an inner rotor corresponding to the fitting portion of the outer rotor, having a plurality of fitting portions protruding radially outward on an outer peripheral portion, and having a plurality of wheel mounting holes on an inner peripheral portion, A caulking pin fitted in a pin hole formed by a substantially semicircular recess formed in each of the fitting portions, and the caulking pin can be caulked to transmit torque between the outer rotor and the inner rotor. In the floating type disk brake rotor integrally fixed to the outer rotor, the outer rotor and the inner rotor have a configuration in which one side surface of the fitting portion has a sheared surface that is divided after quenching. Quenching in a state where one side of the fitting part of the rotor and the inner rotor are connected, the thermal strain generated at that time can be absorbed by the plastic deformation of the connecting part, maintaining the quality having the desired dimensional accuracy, and It is possible to provide a disk brake rotor at low cost.
[0036]
The manufacturing method further includes a pressing step of forming the outer rotor and the inner rotor integrally with each other through a connecting portion extending in a circumferential direction, wherein a fitting portion of the outer rotor and the inner rotor has a different phase in a circumferential direction. Therefore, the diameters of the two rotors can be set appropriately. Therefore, the annular clearance in the fitting portion between the two can be appropriately set in a wide range according to the use conditions, the size, and the like, and the degree of freedom in design increases.
[0037]
Furthermore, after the pressing step, at least the sliding portion of the outer rotor is subjected to surface hardening treatment by induction hardening, and then, if the connecting portion is divided by press working, thermal distortion due to quenching is caused by plastic deformation of the connecting portion. It is possible to provide a disk brake rotor that can absorb the energy, maintain quality having desired dimensional accuracy, and reduce costs.
[Brief description of the drawings]
FIG. 1A is a plan view showing an embodiment of a disc brake rotor according to the present invention.
(B) is a sectional view of (a).
FIG. 2A is a cross-sectional view illustrating a main part of a caulking pin according to the present invention before caulking.
(B) is an important section sectional view showing the crimping pin according to the present invention after crimping.
(C) is a sectional view taken along line II-II of (b).
FIG. 3 is an explanatory view showing a step of punching a drain hole of the disc brake rotor according to the present invention.
FIG. 4 is an explanatory view showing a step of punching a through hole of the disc brake rotor according to the present invention.
FIG. 5 is an explanatory view showing a step of separating the outer rotor and the inner rotor according to the present invention.
FIG. 6 is a plan view showing a conventional floating type disk brake rotor.
FIG. 7A is an enlarged sectional view of a main part of FIG. 6;
(B) is a sectional view taken along line VII-VII of (a).
FIG. 8 is an explanatory view showing a manufacturing process of a conventional disk brake rotor.
[Explanation of symbols]
1 ... Disc brake rotor 2 ... Outer rotor 2 '... Outer rotor equivalent portion 2a, 3a ... Recess 2b .., Fitting portion 2b ′, 3b ′, fitting portion 2c, sliding portion 2d, drainage holes 2e, 3c,. ··· Recess 3 ········· Inner rotor 3 ′ ········································ Washer 5a ······ Inlay part 6 ·························································· · Pin hole 8 · · · · · · Mounting holes 9, 9 ', 9 "· · · Material 9a · · · · · Center hole 9b · · · · · · Small hole 10 · · · ····· Through hole 11 ········· Connection part 51 · ... Disc brake rotor 52 Outer rotor 52a Sliding parts 52b, 53a Indent 52d Drain hole 53 · Inner rotor 54 ········ Disc spring 55 ······ Washer 56 ·········································· · Pin hole 58 ······ Mounting hole δ ·················· Pin clearance

Claims (4)

An outer rotor having a sliding portion on an outer peripheral portion and having a plurality of fitting portions projecting radially inward on an inner peripheral portion, and an outer peripheral portion corresponding to the fitting portion of the outer rotor, An inner rotor having a plurality of outwardly protruding fitting portions and having a plurality of wheel mounting holes on an inner peripheral portion, and a substantially semicircular recess formed in each of the fitting portions. A floating type disc brake rotor comprising a caulking pin fitted into a pin hole, and caulking the caulking pin to integrally fix the outer rotor and the inner rotor so that torque can be transmitted.
A disc brake rotor having a sheared surface divided after quenching on one side surface of a fitting portion between the outer rotor and the inner rotor. An outer rotor having a sliding portion on an outer peripheral portion and having a plurality of fitting portions projecting radially inward on an inner peripheral portion, and an outer peripheral portion corresponding to the fitting portion of the outer rotor, An inner rotor having a plurality of outwardly protruding fitting portions and having a plurality of wheel mounting holes on an inner peripheral portion, and a substantially semicircular recess formed in each of the fitting portions. A crimping pin fitted into a pin hole, wherein the crimping pin is crimped to fix the outer rotor and the inner rotor integrally so as to be able to transmit torque, and a method of manufacturing a floating type disc brake rotor,
The fitting part of the outer rotor and the inner rotor has a different phase in the circumferential direction, and includes a pressing step of integrally forming the outer rotor and the inner rotor via a connecting part extending in the circumferential direction. Manufacturing method of disc brake rotor. 3. The method of manufacturing a disc brake rotor according to claim 2, wherein after the pressing step, at least a sliding portion of the outer rotor is subjected to a surface hardening treatment by induction hardening, and thereafter, the connecting portion is separated by press working. The method according to claim 3, wherein the recess of the fitting portion is formed by press working.

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