BRAKE DISK

Abstract: A brake disk comprises a ring-shaped braking section (2) having plural inner circumferential spokes (5, 6) provided on its inner circumferential surface, a hub section (3) for mounting to an axle and provided with plural outer circumferential spokes (13, 14), a dish-shaped spring (24) being so placed on the same side surfaces of paired two inner and outer circumferential spokes (5, 13) as to be in pressure contact commonly therewith, and a connecting pin (23) used together with the dish-shaped spring (24) to connect said paired two spokes (5, 13) and being so disposed as to allow both of the paired two spokes (5, 13) to move relatively slightly with respect to each other, said spokes (5, 6; 13, 14) being directed radially. Each spoke (5, 13) of the pair is provided on a surface of the end portion thereof facing that of the other one with either a peripheral groove (9) or a ridge (17), both of which are so arranged as to fit in with each other in a floating or loose-fit manner, and further with a concave (11, 19) so arranged as to face the other one opposite thereto and to work together to hold in place the connecting pin (23) linked with the dish-shaped spring (24). Connecting pin (23) and dish-shaped spring (24) may be provided at every other pair. A head portion (26) of the connecting pin (23) is formed in the shape of said dish-shaped spring (24).

Description: FIELD OF THE INVENTION This invention relates to a floating type brake disk used in a disk brake for a motor vehicle. BACKGROUND OF THE INVENTION In a floating type brake disk, a braking section and a hub section are each a separate unit and are connected to each other so that even when the braking section becomes thermally expanded with heat produced by friction of a brake pad with application of a braking force, such thermal expansion is confined only to the braking section and, on top of that, since the braking section is of a simple ring shape and not bound by the hub section, it does not cause any significant distortion to a brake surface, thus bringing about an advantage that the braking action remains consistent. In a brake disk of this type, it was usual that a measure of having a dish-shaped spring put in pressure contact with the side surface of each of both sections was taken in order to restrict a relative movement in the axial direction of both the braking section and the hub section with respect to each other and to prevent noise that could result from loosening of the two sections. (Jikkai Sho 60-3333 is one example thereof.) In the foregoing prior art, it was necessary to use a dish-shaped spring having a greater spring constant and durability because the load making both the braking section and the hub section move relatively in the axial direction should be supported by resilience of the dish-shaped spring. BRIEF SUMMARY OF THE INVENTION According to this invention, means provided to solve the foregoing problems is such that movement relative to each other of the braking section and the hub section is controlled not only by the dish-shaped spring but also by having both sections engaged in part with each other so as to avoid the dish-shaped spring having an excessive load applied thereto. More specifically, in a brake disk of the type that a rim-shaped braking section has plural inner circumferential spokes provided at its inner circumferential surface, a hub section connected to an axle is provided with plural outer circumferential spokes, a dish-shaped spring is so placed on the same side surfaces of paired two inner and outer circumferential spokes as to be in pressure contact commonly therewith, and a connecting pin used together with the dish-shaped spring to connect the paired two spokes is so disposed as to allow both of the paired two spokes to move relatively slightly with respect to each other, said means of the present invention is characterized in that each spoke of the pair is provided on a surface of the end portion thereof facing that of the other one with either a peripheral groove or a ridge, both of which are so arranged as to fit with each other in a floating manner, and further with a recess or cavity so arranged as to face the other one opposite thereto and together hold in place the connecting pin linked with the dish-shaped spring. According to the foregoing means, a backlash or improper engagement at the joint of the breaking section with the hub section is effectively checked by the dish-shaped springs so that no noise may be generated and, if a thrust in the axial direction exceeding the resilience of the dish-shaped spring is applied, the peripheral groove and the ridge will become engaged with each other to check the relative movement thereof. BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the invention will be described in detail with reference to the drawings, wherein: Fig. 1 is a front view of the preferred embodiment of the invention; Fig. 2 is a sectional side view thereof; Fig. 3a is a partial front view of a braking section thereof; Fig. 3b is a sectional partial side view of a braking section thereof; Fig. 4a is a partial front view of a hub section thereof; Fig. 4b is a sectional partial side view of a hub section thereof; Fig. 5 is an enlarged view of portion A in Fig. 1; and Fig. 6 is an enlarged view of portion B in Fig. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, reference numeral 1 generally denotes a brake disk, reference numeral 2 denotes a braking section thereof, and reference numeral 3 denotes a hub for mounting on an axle. The braking section 2 is ring-shaped and has vent holes 4 and a plurality of short radially inwardly directed spokes 5,6 distributed alternatingly at equal intervals along the inner circumference of the braking section. Peripheral grooves 9, 10 that run in the circumferential direction are provided on inner end surfaces 7, 8 of spokes 5, 6 while a semi-circular axially directed concave recess 11 for interconnection is provided only on spoke 5, as shown in Figs. 3a and 3b. The hub section has an axle hole 12 at its center and radially outwardly directed spokes 13, 14 on its outer circumference. The spokes 13, 14 have peripheral ridges 17, 18 projecting from outer end surfaces 15, 16 thereof, as shown in Figs. 4a and 4b. The dimensions of the ridges 17, 18 are such that a small play exists in both the axial and radial directions when the ridge is inserted in the corresponding one of the circumferential grooves 9, 10. In addition, each spoke 13 is provided with a U-shaped axially directed concave recess 19 for interconnection. Again referring to the drawings, reference numeral 20 denotes a mounting hole used to mount the brake disk 1 onto the axle, whereas reference numeral 21 denotes an opening provided for the purpose of decoration. For connecting the braking section 2 and the hub section 3 to each other, they are first concentrically positioned but out of phase in terms of their rotational angle, and then either of sections 2, 3 is rotated until the ridges 17, 18 respectively engage the circumferential grooves 9, 10 in such a manner that the concave recesses 11, 19 overlap. As shown in Fig. 6, the braking section 2 and the hub section 3 are held in place by means of a connecting pin 23 inserted in recesses 11, 19 and the dish-shaped spring 24. The dish-shaped spring 24 has a thick stepped portion 25 on its periphery and is dish-shaped, whereas pin 23 has a head portion 26, a stepped portion 27, and a caulking portion 28 by which the dish-shaped spring 24 is secured in place. The head portion of the pin 23 in accordance with the preferred embodiment has the same shape as the dish-shaped spring 24 so as to make it resilient. Alternatively, the pin can also be shaped so as to be rigid rather than resilient if so desired. The braking section 2 and the hub section 3 transmit a braking torque through the pin 23 while movement in the axial direction is restricted by the circumferential grooves, 9, 10 and the ridges 17, 18 to such an extent that there may be only slight play. And both of spokes 5, 13 are provided on their side surfaces with the dish-shaped spring which is in pressure contact therewith, so that any clattering noise generated due to a clearance formed in the turning, radial and axial directions of each component member may be prevented by the frictional force of the dish-shaped spring 24 and so that movement in the axial direction of the braking section which can be caused by external force applied at the time of brake application may be absorbed by flexion of the dish-shaped spring 24. Additionally, since the braking section and the hub section are separate from each other, thermal deformation of the braking section 2 is allowed to take place freely, thereby preventing distortion of the braking surface. Furthermore, when relative movement of the braking section and the hub section becomes unduly large, the circumferential grooves 9, 10 and the side surfaces of the ridges 17, 18 contact each other to prevent any further such movement, whereby no undue load is applied to the dish-shaped spring 24. In the preferred embodiment, only every other pair of the spokes, that is, 5 and 13, receives the pin 23, but in the alternative, each pair of spokes, including spokes 6, 14, may be provided with recesses for receiving a pin, if desired. In yet another arrangement, each pair of spokes 6, 14 not provided with pin 23 may be eliminated if the hub is for use in a lightweight motor vehicle. As described in the foregoing, the braking section and the hub section according to the preferred embodiment of the invention are provided respectively with circumferential grooves and ridges which are arranged to receive or absorb undue external forces, whereby the dish-shaped spring will not be damaged by external forces or rendered inoperative.

Claims: A brake disk of the type comprising a ring-shaped braking section (2) having plural inner circumferential spokes (5, 6) provided on its inner circumferential surface, a hub section (3) for mounting on an axle and provided with plural outer circumferential spokes (13, 14), a dish-shaped spring (24) being so placed on the same side surfaces of paired two inner and outer circumferential spokes (5, 13) as to be in pressure contact commonly therewith, and a connecting pin (23) used together with the dish-shaped spring (24) to connect said paired two spokes (5, 13) and being so disposed as to allow both of the paired two spokes (5, 13) to move relatively slightly with respect to each other, characterized in that each spoke (5, 13) of the pair is provided on a surface of the end portion thereof facing that of the other one with either a peripheral groove (9) or a ridge (17), both of which are so arranged as to fit in with each other in a floating or loose-fit manner, and further with a concave (11, 19) so arranged as to face the other one opposite thereto and to work together to hold in place the connecting pin (23) linked with the dish-shaped spring (24). A brake disk according to claim 1, characterized in that said spokes (5,6) provided on the inner circumferential surface are radially inwardly directed, and that said spokes (13,14) provided on the outer circumferential surface are radially outwardly directed. A brake disk as claimed in claim 1 or 2, characterized in that a head portion (26) of the connecting pin (23) is formed in the shape of said dish-shaped spring (24). A brake disk as claimed in any one of claims 1 to 3, characterized in that said connecting pin (23) and said dish-shaped spring (24) are provided at only some of said pairs of spokes (5, 6; 13, 14). A brake disk as claimed in claim 4, characterized in that said connecting pin (23) and said dish-shaped spring (24) are provided at every other pair of spokes (5, 13). A brake disk as claimed in any one of claims 1 to 5, characterized in that said connecting pin (23) and said dish-shaped spring (24) are connected with each other and secured in place by a caulking portion (28) of said pin.

Inventors: IZUMINE, ZENZO
Applicants: KABUSHIKI KAISHA YUTAKA GIKEN (ALSO TRADING AS YUTAKA GIKEN CO., LTD.)
Application year: 1988
Main classification: F16D65
IPC codes: F16D65, F16D69, F16B5