Rear frame for two-wheeled motor vehicle and method of casting the same

Abstract

A rear frame 5 of a motorcycle 1 is of a longitudinally elongated shape and provided with a pair of right and left rail parts 5a connected by a plurality of cross members 5b. The rear frame 5 is formed by die-casting and a plurality of gate parts G1 to G5 to pour the molten metal through are located separately along the rail parts 5a. It is possible to shorten the metal pouring process and prevent casting defects such as underfills.

Description

technical field

[0001] The invention relates to a rear frame of a motorcycle (motor vehicle). Background technique

[0002] The rear frame of a motorcycle has a long overall shape in the front-rear direction (vertical direction), and is provided with a pair of left and right rails connected by a plurality of beams (for example, refer to Patent Document 1 and Patent Document 2).

[0003] Patent Document 1 discloses that the rear frame is integrally formed by casting, etc., and Patent Document 2 discloses that during casting, molten metal is poured from one gate on the rear side so that The fluidity of molten metal is good, and the local temperature difference is reduced, so that excellent casting quality and light weight can be achieved.

[0004] Patent Document 1: Patent No. 2706956 (page 3, FIGS. 5 to 6 )

[0005] Patent Document 2: Japanese Unexamined Patent Publication No. H11-010280 (page 3, FIG. 4, FIG. 5)

[0006] In this way, in the case of integrally forming the r...

Examples

Embodiment Construction

[0030] Next, the rear frame of the motorcycle and the casting method of the rear frame of the motorcycle according to the present invention will be described with reference to the drawings.

[0031] Fig. 1 is a side view of a two-wheeled motorcycle using a rear frame, Fig. 2 is a side view of the body frame, Fig. 3 is a side view of the body frame before the rear frame is installed, and Fig. 4 is along IV of Fig. 2 - A cross-sectional view of line IV, Fig. 5 is a cross-sectional view along line V-V of Fig. 2 .

[0032] For the two-wheeled motorcycle 1 of this embodiment, the body frame 2 is composed of a main frame 3, a rear arm bracket 4 and a rear frame 5, the main frame 3, the rear arm bracket 4 are formed by casting, and the rear frame 5 Shaped by die casting.

[0033] The main frame 3 has a front pipe portion 3a on the front side, and frame portions 3b extend rearward from both left and right sides of the front pipe portion 3a, and the upper side 4a of the rear arm brack...

technical field

[0001] The invention relates to a rear frame of a motorcycle (motor vehicle). Background technique

[0002] The rear frame of a motorcycle has a long overall shape in the front-rear direction (vertical direction), and is provided with a pair of left and right rails connected by a plurality of beams (for example, refer to Patent Document 1 and Patent Document 2).

[0003] Patent Document 1 discloses that the rear frame is integrally formed by casting, etc., and Patent Document 2 discloses that during casting, molten metal is poured from one gate on the rear side so that The fluidity of molten metal is good, and the local temperature difference is reduced, so that excellent casting quality and light weight can be achieved.

[0004] Patent Document 1: Patent No. 2706956 (page 3, FIGS. 5 to 6 )

[0005] Patent Document 2: Japanese Unexamined Patent Publication No. H11-010280 (page 3, FIG. 4, FIG. 5)

[0006] In this way, in the case of integrally forming the r...

Examples

Embodiment Construction

[0030] Next, the rear frame of the motorcycle and the casting method of the rear frame of the motorcycle according to the present invention will be described with reference to the drawings.

[0031] Fig. 1 is a side view of a two-wheeled motorcycle using a rear frame, Fig. 2 is a side view of the body frame, Fig. 3 is a side view of the body frame before the rear frame is installed, and Fig. 4 is along IV of Fig. 2 - A cross-sectional view of line IV, Fig. 5 is a cross-sectional view along line V-V of Fig. 2 .

[0032] For the two-wheeled motorcycle 1 of this embodiment, the body frame 2 is composed of a main frame 3, a rear arm bracket 4 and a rear frame 5, the main frame 3, the rear arm bracket 4 are formed by casting, and the rear frame 5 Shaped by die casting.

[0033] The main frame 3 has a front pipe portion 3a on the front side, and frame portions 3b extend rearward from both left and right sides of the front pipe portion 3a, and the upper side 4a of the rear arm brack...

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