CN2278644Y - bicycle crank structure - Google Patents

Abstract

The utility model relates to a bicycle drive mechanism's accessory in the land vehicle is used to the trackless, it produces a cross-section with integrative stamping forming mode and is the crank body of U-shaped, and make the both ends of this crank body have a big hole and a little hole respectively, make a sleeve and a nut in addition, the corresponding two sides of this sleeve form a trepanning and a screw respectively, embolia big hole and little hole respectively with this sleeve and nut and weld firmly and compel tightly, force into the U type fluting of this crank body with a slab in addition and cover, then at the crank body, the outside cladding plastic material of sleeve and nut combines as an organic wholely, make the integrated manufacturing more simple and easy, reduce cost and increase articulate intensity and torsion.

Description

bicycle crank structure

The utility model relates to a bicycle transmission mechanism in a trackless land vehicle, in particular to a crank structure with more convenient manufacture, low cost, high strength and large torque.

The bicycle crank is a mechanical component installed on the central axis of the bicycle driving sprocket. One end of the crank is assembled with a pedal, so that when the rider steps on the pedal, the crank can drive the driving sprocket to rotate, and then the chain will drive it. The small sprocket of the rear wheel rotates, as shown in Figure 4, the traditional bicycle crank structure is that a set of holes A1 and a large screw hole A2 are respectively provided on the corresponding two surfaces at one end of the crank body A, and at the other end of the crank body A A small threaded hole A3 is provided, and in order to make the appearance more beautiful, the outer surface can be coated with a combination of plastic material B, and the polygonal central shaft of the driving sprocket can be sleeved by the polygonal sleeve hole A1. And the crank body A is fixed on the driving sprocket by screwing the nut of the external thread shape into the large screw hole A2, and the small screw hole A3 can be used for locking a pedal. When the traditional bicycle crank is manufactured, the steel is heated to a certain temperature and then forged. After forming, a set of holes A1 and a large screw hole A2 are machined at one end of the crank body A, and a large screw hole A2 is tapped at the other end. Make a small screw hole A3; however, because the surface of the crank body after forging is very hard, it is very difficult to process and tap, and tools with a relatively high hardness are not enough to do it. And in order to have proper toughness after forming, heat treatment must be carried out after forging, processing, and attacking to change its internal metallographic structure. Therefore, its manufacture is very troublesome and difficult. And it is difficult to produce in large quantities to reduce the manufacturing cost of the product, and its whole is a solid structure, not only the weight is very heavy, but also directly increases the manufacturing cost.

The purpose of the utility model is to propose a bicycle crank structure mainly composed of a crank body, a sleeve, a nut and a plate, which not only reduces the overall weight of the crank body, but also increases the strength and torsion of the crank. And the manufacturing cost is reduced, thereby solving the problems existing in the prior art.

The technical solution adopted by the utility model is that it is mainly composed of a crank body, a sleeve, a nut and a plate, and it is respectively provided with a set of holes and a screw hole on the opposite sides of the crank body. The hole is set on the drive shaft, and is locked in the screw hole with an external threaded nut. There is a through screw hole at the other end of the crank body, so that the pedal can be locked, and the outside of the crank body is covered There are plastic materials, and it is characterized in that: the crank body is formed by one-piece stamping into a U-shaped cross-section, and has a large hole and a small hole at both ends, and is provided with a sleeve, a nut and a The corresponding two sides of the sleeve are respectively provided with a set of holes and a screw hole, so that the sleeve is inserted into the large hole at one end of the crank body and then welded, and the nut is inserted into the small hole at the other end of the crank body After the hole is welded, the plate is formed into a U-shaped slot corresponding to the crank body, and side plates are provided on its two sides. The distance between the outer surfaces of the two side plates is slightly larger than the two inner surfaces of the crank body. According to this, the two side plates can be forced into the crank body so that the plates cover the crank body, and the sleeve and the outside of the nut are coated with a combined plastic material.

The utility model can not only reduce the overall weight of the crank body, but also increase its strength and torsion force, and the torsion force it can bear is about 300 kg/mm. The manufacture is also simpler and the production cost is reduced, so it is practical.

Fig. 1 is a three-dimensional exploded view of the utility model.

Fig. 2 is a plane cross-sectional view of the overall assembled structure of the utility model.

Fig. 3 is a three-dimensional exploded view of the utility model assembled on a bicycle sprocket.

Fig. 4 is a plan sectional view of a conventional crank structure.

Now further illustrate preferred specific embodiments of the present utility model in conjunction with above-mentioned each accompanying drawing. As shown in Figure 1, the utility model is mainly composed of a crank body (1), a sleeve (2), a nut (3) and a plate (7); wherein, the crank body (1) is Appropriate steel is integrally stamped and formed into a U-shaped section, with protruding side plates on both sides, and a hollow state in the middle, so that the whole can not only reduce weight, but also have sufficient strength without additional heat treatment , and it punches out a large hole (11) and a small hole (12) respectively at the two ends of the crank body (1) while stamping and forming. In addition, the sleeve (2) and the nut (3) are independently manufactured and processed, and the sleeve (2) is provided with a polygonal sleeve hole (21) and a screw hole on its corresponding two sides respectively. (22), and the nut (3) also has an internal thread, so that the sleeve (2) can be inserted into the large hole (11) at one end of the crank body (1) and then welded by spot welding , and the nut (3) is inserted into the small hole (12) at the other end of the crank body (1) and then welded by spot welding; the plate (7) is according to the U of the crank body (1). shaped slot, and extend side plates (71) on its two sides. The distance between the outer surfaces of the two side plates (71) is slightly greater than that between the U-shaped inner walls of the crank body (1). distance, so that the two side plates (71) can be forced into the crank body (1) and fixed, and finally the crank body (1), the sleeve (2), the nut (3) and the plate are fixed according to actual needs. (7) The outside is covered with plastic material (4) so that the crank body (1), the sleeve (2), the nut (3) and the plate (7) are combined into one body and the overall appearance is improved.

By the bicycle crank made above, its sleeve (22) can be passed through the center hole (51) provided by the drive sprocket (5) and then the end of the sleeve (2) can be bent and deformed to drive the drive sprocket (5). The sprocket (5) is combined and fixed with the crank body (1), and then the drive shaft (8) located on the bicycle is inserted into the sleeve hole (21) of the sleeve (2), and then the nut lock in the form of an external thread The screw hole (22) fixed on the sleeve (2) fixes the drive sprocket (5) and the drive shaft (8) together; and the screw rod (61) provided at one end of the pedal (6) can be locked on the nut (3).

Claims (1)

1. A bicycle crank structure, which is respectively provided with a set of holes and a screw hole on two opposite sides of one end of the crank body. The set of holes is sleeved on the drive shaft, and is locked in the screw hole with an externally threaded nut. There is a through screw hole at the other end of the crank body, so that it can lock the pedal, and the outside of the crank body is covered with plastic material, and the feature is that the crank body is integrally stamped and formed into a U-shaped section , and make it have a large hole and a small hole at both ends, and a sleeve, a nut and a plate, and the corresponding two sides of the sleeve are respectively provided with a set of holes and a screw hole, The sleeve is inserted into the large hole at one end of the crank body and then welded. The nut is inserted into the small hole at the other end of the crank body and welded. The plate forms a U-shaped groove corresponding to the crank body. And there are side plates on its two sides, the distance between the outer surfaces of the two side plates is slightly larger than the two inner surfaces of the crank body, so that the two side plates can be forced into the crank body so that the plates cover the crank The body, the sleeve and the outside of the nut are covered with plastic materials.

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