Cast wheel

Abstract: To provide a cast wheel including a hub (11 1 ), a rim (12 1 ) coaxially surrounding the hub (11 1 ), and a plurality of spokes (14 1 , 15 1 ) connecting the hub (11 1 ) to the rim (12 1 ), which are integrally formed, wherein a relatively large opening portion is ensured between the hub (11 1 ) and the rim (12 1 ) for improving the maintenance performance of a disk brake or the like while keeping the rigidity of the wheel. A plurality of spoke pairs (13 1 ) composed of spokes (14 1 , 15 1 ) being close to each other along the circumferential direction of a hub (11 1 ) and a rim (12 1 ) are arranged at equal intervals along the circumferential direction in such a manner that each interval between the spoke pairs (13 1 ) is larger than each interval between the spokes (14 1 , 15 1 ).

Description: The present invention relates to a cast wheel including a hub, a rim coaxially surrounding the hub, and a plurality of spokes arranged between the hub and the rim, wherein the hub, rim and spokes are integrally formed. Cast wheels of this type have been disclosed, for example, in Japanese Utility Model Publication No. Hei 4-51041, and in Patent Abstracts of Japan, vol. 11, no. 98 (M-575). The cast wheel shown in the latter document is provided with spokes having substantially an U-shaped cross-section. In the above-described cast wheels, since spokes are arranged in equal intervals along the circumferential direction of a hub and a rim, each interval between the spokes is relatively small and in some cases, it is difficult for a hand to enter the interval upon maintenance of a disk brake or the like. Such a disadvantage is made significant for a vehicle having small wheels such as a scooter. US-A-4,760,718 discloses a cast wheel according to the preamble of claim 1. In view of the foregoing, the present invention has been made, and an object of the present invention is to provide a lightweight cast wheel maintaining a relatively large opening portion between a hub and a rim for making easy maintenance of a disk brake or the like while increasing or keeping a rigidity of the wheel. To achieve the above object, according to the invention, there is provided a cast wheel as described in claim 1. According to the invention described in claim 1, consequently a relative large opening portion can be ensured between the hub and the rim. This makes it possible to increase the maintenance performance for a disk brake and the like mounted on the wheel while sufficiently keeping the rigidity of the wheel. In particular the spokes are arranged in a triangular shape resulting in the increased rigidity of the wheel. According to the invention described in claim 2, in addition to the configuration of the invention described in claim 1, each of the spoke pairs are disposed between the hub and the rim in such a manner that an interval between the spokes forming the spoke pair is made smaller as nearing the hub. Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1: A side view of a motor-bicycle using the cast wheels of the present invention as front and rear wheels. Fig. 2: A side view of the cast wheel of the present invention applied to a front wheel. Fig. 3: A sectional view taken on line 3-3 of Fig. 2. Fig. 4: A sectional view taken on line 4-4 of Fig. 2. Fig. 5: A side view of a cast wheel of the present invention applied to a rear wheel. Fig. 6: A sectional view taken on line 6-6 of Fig. 5. Figs. 1 to 6 show one embodiment of the present invention. Referring first to Fig. 1, the front portion of a body frame F of a scooter type motor-bicycle V is covered with a front portion 20 of a front cover which has a front carrier 19 and a rear portion 22 of the front cover which has a front inner rack 21. A front fork 5 is rotatably supported on the front end portion of the body frame F in such a manner as to be turnable right and left by a steering handle H. A front wheel W F including a cast wheel 1 1 and a tire 2 1 mounted around the outer periphery of the cast wheel 1 1 is covered with a movable front fender 23 and is rotably supported by the lower end of the front fork 5. A disk brake B F having a brake disk 17 and a caliper 18 is mounted on the front wheel W F . The rear portion of the body frame F is covered with a rear cover 24, and a seat 26 for allowing a driver putting his feet on a step 25 to sit thereon is provided on the upper portion of the rear cover 24. A swing unit S including an engine E and a mission case 7 is vertically rockably supported on the rear portion of the body frame F. A pair of right and left cushions are provided between the swing unit S and the body frame F. A rear wheel WR including a cast wheel 1 2 and a tire 2 2 mounted around the outer periphery of the cast wheel 1 2 is covered with a rear fender 27 extending rearward from the rear cover 24, and it is rotatably supported by the mission case 7. A drum brake B R is mounted on the rear wheel W R . An air cleaner 8 is disposed on the upper portion of the mission case 7 on the left side from the rear wheel W R . A muffler 9 is disposed on the right side from the rear wheel W R . Next, the cast wheel 1 1 of the front wheel W F will be described with reference to Figs. 2 to 4. The cast wheel 1 1 includes a hub 11 1 rotatably supported by the lower end of the front fork 5, a rim 12 1 coaxially surrounding the hub 11 1 and mounting the tire 2 1 , and a plurality (for example three pieces) of spoke pairs 13 1 , ..., 13 1 provided between the hub 11 1 and the rim 12 1 . The hub 11 1 , the rim 12 1 and the spoke pairs 13 1 , ..., 13 1 are integrally formed by casting of a light alloy such as an aluminum alloy. A plurality (for example three pieces) of mounting bosses 16,..., 16 for mounting the brake disk 17 (see Fig. 1) of the disk brake B F are projectingly provided on the hub 11 1 . Each spoke pair 13 1 is composed of spokes 14 1 , 15 1 which are close to each other along the circumferential direction of the hub 11 1 and the rim 12 1 . One spoke 14 1 is formed substantially in a U-shaped in cross-section which is opened on the left side of the front wheel W F . On the other hand, the other spoke 15 1 is formed substantially in a U-shaped in cross-section which is opened on the right side of the front wheel W F . The spokes 14 1 , 15 1 are arranged between the hub 11 1 and the rim 12 1 in such a manner that each of the spokes 14 1 , 15 1 is inclined to one side in the circumferential direction with respect to the radial direction of the hub 11 1 and each interval between the spokes 14 1 , 15 1 is made smaller as nearing the hub 11 1 . In other words, the spokes 14 1 , 15 1 are arranged substantially in a triangular shape. The spoke pairs 13 1 , ..., 13 1 are arranged at a plurality of points, for example, three points spaced at equal intervals along the circumferential direction of the hub 11 1 and the rim 12 1 in such a manner that each interval between the spoke pairs 13 1 , ..., 13 1 is larger than each interval between the spokes 14 1 , 15 1 forming each spoke pair 13 1 . Referring to Figs. 1, 5 and 6, the cast wheel 1 2 of the rear wheel W R includes a hub 11 2 capable of containing the drum brake B R , a rim 12 2 coaxially surrounding the hub 11 2 and mounting the tire 2 2 , and a plurality (for example three pieces) of spoke pairs 13 2 , ..., 13 2 provided between the hub 11 2 and the rim 12 2 . The hub 11 2 , the rim 12 2 and the spoke pairs 13 2 , ..., 13 2 are integrally formed by casting of a light alloy such as an aluminum alloy. Each spoke pair 13 2 is composed of spokes 14 2 , 15 2 which are close to each other along the circumferential direction of the hub 11 2 and 12 2 . One spoke 14 2 is formed substantially in a U-shaped in cross-section which is opened on the left side of the rear wheel W R . On the other hand, the other spoke 15 2 is formed substantially in a U-shaped in cross-section which is opened on the right side of the rear wheel W R . The spokes 14 2 , 15 2 are arranged between the hub 11 2 and the rim 12 2 in such a manner that each interval between the spokes 14 2 , 15 2 is made smaller as nearing the hub 11 2 . The spoke pairs 13 2 , ..., 13 2 are arranged at a plurality of points, for example, three points spaced at equal intervals along the circumferential direction of the hub 11 2 and the rim 12 2 in such a manner that each interval between the spoke pairs 13 2 , ..., 13 2 is larger than each interval between the spokes 14 2 , 15 2 forming each spoke pair 13 2 . The function of this embodiment will be described below. In the cast wheel (1 1 , 1 2 ), a plurality of the spokes (14 1 , 15 1 ; 14 2 , 15 2 ) connecting the hub (11 1 , 11 2 ) to the rim (12 1 , 12 2 ) is constituted of a plurality of the spoke pairs (13 1 , ...; 13 2 , ...) each being composed of the spokes (14 1 , 15 1 ; 14 2 , 15 2 ) close to each other. The spoke pairs (13 1 , ...; 13 2 , ...) are arranged at equal intervals along the circumferential direction in such a manner that each interval between the spoke pairs (13 1 , ...; 13 2 , ...) is larger than each interval between the spokes (14 1 , 15 1 ; 14 2 , 15 2 ). Accordingly, it becomes possible to ensure each relatively large opening portion between the spoke pairs (13 1 , ...; 13 2 , ...) while keeping the rigidity of the wheel, and hence to make easy maintenance for a disk brake B F and the drum brake B R . Since each of the spokes (14 1 , 15 1 ; 14 2 , 15 2 ) forming the spoke pairs (13 1 , ...; 13 2 , ...) is formed substantially in a U-shape which is opened on the left or right side of the wheel, the rigidity of the wheel can be increased while the weight of the wheel is reduced. Also, since the spokes (14 1 , 15 1 ; 14 2 , 15 2 ) are provided in a triangular shape between the hub (11 1 ; 11 2 ) and the rim (12 1 ; 12 2 ), the rigidity of the wheel can be increased. While the embodiment of the present invention has been described in detail, the present invention is not limited thereto, and many changes in design are possible without departing from the scope of the claims. For example, the number of the spoke pairs is not limited to three, and the spokes pairs may be provided at four points in the circumferential direction between a hub and a rim. In summary it is an object to provide a cast wheel including a hub, a rim coaxially surrounding the hub, and a plurality of spokes connecting the hub to the rim, which are integrally formed, wherein a relatively large opening portion is ensured between the hub and the rim for improving the maintenance performance of a disk brake or the like while keeping the rigidity of the wheel. It is provided a plurality of spoke pairs 13 1 composed of spokes 14 1 , 15 1 being close to each other along the circumferential direction of a hub 11 1 and a rim 12 1 are arranged at equal intervals along the circumferential direction in such a manner that each interval between the spoke pairs 13 1 is larger than each interval between the spokes 14 1 , 15 1 .

Claims: A cast wheel comprising a hub (11 1 ; 11 2 ), a rim (12 1 ; 12 2 ) coaxially surrounding said hub (11 1 ; 11 2 ), and a plurality of spoke pairs (13 1 ; 13 2 ) arranged between said hub (11 1 ; 11 2 ) and said rim (12 1 ; 12 2 ), each spoke pair (13 1 ; 13 2 ) being composed of a pair of spokes (14 1 , 15 1 ; 14 2 , 15 2 ) close to each other in the circumferential direction of said hub (11 1 ; 11 2 ) and said rim (12 1 ; 12 2 ), said spoke pairs (13 1 ; 13 2 ) being arranged at equal intervals along said circumferential direction in such a manner that each interval between said spoke pairs (13 1 ; 13 2 ) is larger than each interval between said spokes (14 1 , 15 1 ; 14 2 , 15 2 ) forming said spoke pairs (13 1 ; 13 2 ), said hub (11 1 ; 11 2 ), said rim (12 1 ; 12 2 ) and said spokes (14 1 , 15 1 ; 14 2 , 15 2 ) being integrally formed, characterized in that one spoke (14 1 ; 14 2 ) of the pair of spokes (14 1 , 15 1 ; 14 2 , 15 2 ) is formed substantially in a U-shaped cross-section which is opened in one side of the wheel and the other spoke (15 1 ; 15 2 ) of the pair of spokes (14 1 , 15 1 ; 14 2 , 15 2 ) is formed substantially in a U-shaped cross-section which is opened in the other side of the wheel, and in that each of said spokes (14 1 , 15 1 ; 14 2 , 15 2 ) is inclined to one side in the circumferential direction with respect to the radial direction of the hub (11 1 ; 11 2 ) in such a manner the spokes of each pair of spokes are arranged in a triangular shape. A cast wheel according to claim 1, wherein said spokes (14 1 , 15 1 ; 14 2 , 15 2 ) forming each of said spoke pairs (13 1 ; 13 2 ) are disposed between said hub (11 1 ; 11 2 ) and said rim (12 1 ; 12 2 ) in such a manner that an interval between said spokes (14 1 , 15 1 ; 14 2 , 15 2 ) is made smaller as nearing said hub (11 1 ; 11 2 ).

Inventors: OKAZAKI YASUNORI, OKAZAKI, YASUNORI
Applicants: HONDA MOTOR CO LTD, HONDA GIKEN KOGYO KABUSHIKI KAISHA
Application year: 1996
Main classification: B60B1
IPC codes: B60B1, B60B3