CN212155423U

CN212155423U - Crankshaft structure of single-cylinder engine

Info

Publication number: CN212155423U
Application number: CN202020739772.8U
Authority: CN
Inventors: 黄第云
Original assignee: Guangxi Yuchai Machinery Co Ltd
Current assignee: Guangxi Yuchai Machinery Co Ltd
Priority date: 2020-05-08
Filing date: 2020-05-08
Publication date: 2020-12-15
Anticipated expiration: 2030-05-08

Abstract

The utility model discloses a single cylinder engine's bent axle structure, including the bent axle body, it includes belt pulley installation axle, connecting rod diameter of axle, gear installation axle and flywheel installation axle. The belt pulley mounting shaft is arranged at one end of the crankshaft body; the shaft diameter of the connecting rod is arranged between two sections of main journals of the crankshaft body, and two ends of the shaft diameter of the connecting rod are connected with the cranks; the gear mounting shaft is arranged between the belt pulley mounting shaft and a section of main journal; the flywheel mounting shaft is arranged at the other end of the crankshaft body; wherein the ratio of the shaft diameter of the connecting rod to the diameter of the main journal is 0.9-0.95, and the ratio of the wall thickness of the crank to the cylinder diameter is 0.2-0.3. The utility model discloses a single cylinder engine's bent axle structure has intensity better, and bending deformation is little advantage.

Description

Crankshaft structure of single-cylinder engine

Technical Field

The utility model relates to an engine manufacturing field especially relates to a single cylinder engine's bent axle structure.

Background

The single cylinder engine crankshaft of the prior art reduces the vibration of a shafting generally by reasonably designing the parameter structure of the single cylinder crankshaft and by counterweights (a flywheel and belt pulleys) at two ends of the crankshaft.

The crankshaft of the existing single-cylinder engine generally bears lower pressure in an engine cylinder, the fillet of the crankshaft is generally subjected to a nitriding process, and the diameter ratio of the crankshaft connecting rod journal to the main journal is generally less than 0.9. The ratio of crank arm thickness to cylinder diameter is typically less than 0.2.

As can be seen from the above, the single cylinder engine crankshaft in the prior art generally has the defects of poor strength and large bending and deformation.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a single cylinder engine's crankshaft structure, because the diameter ratio of its connecting rod diameter of axle and main journal is greater than 0.9 and the ratio of articulate wall thickness and bore is greater than 0.2, consequently it is better to have intensity, advantage that bending deformation is little.

In order to achieve the above object, the utility model provides a single cylinder engine's bent axle structure, including the bent axle body, it includes belt pulley installation axle, connecting rod diameter of axle, gear installation axle and flywheel installation axle. The belt pulley mounting shaft is arranged at one end of the crankshaft body; the shaft diameter of the connecting rod is arranged between two sections of main journals of the crankshaft body, and two ends of the shaft diameter of the connecting rod are connected with the cranks; the gear mounting shaft is arranged between the belt pulley mounting shaft and a section of main journal; the flywheel mounting shaft is arranged at the other end of the crankshaft body; wherein the ratio of the shaft diameter of the connecting rod to the diameter of the main journal is 0.9-0.95, and the ratio of the wall thickness of the crank to the cylinder diameter is 0.2-0.3.

In a preferred embodiment, the surface of the connecting rod shaft diameter is provided with a quenching area, the surface hardness of the quenching area is 50-55HRC, and the quenching depth of the quenching area in the connecting rod shaft diameter part is not less than 2 mm.

In a preferred embodiment, the connecting rod shaft diameter and the connecting part of the crank are provided with round corners, and the radius of the round corners is 2 mm.

In a preferred embodiment, the quenching zone is located at a quenching depth of not less than 1.5mm in a radial direction of 45 degrees of the fillet.

In a preferred embodiment, the quenching area extends to the cranks at two ends of the shaft diameter of the connecting rod, and the extending height is not less than 5 mm.

In a preferred embodiment, two sides of the gear mounting shaft are provided with symmetrical side elevation surfaces, the parts except the side elevation surfaces are arc surfaces, the surface hardness of the arc surfaces is more than 50HRC, and the quenching depth is not less than 1 mm.

In a preferred embodiment, the pulley mounting shaft is provided with a keyway.

In a preferred embodiment, the crankshaft structure of the single-cylinder engine further comprises a balance weight arranged on the crank, and the balance weight is positioned at one end of the crank far away from the shaft diameter of the connecting rod.

Compared with the prior art, the utility model discloses a single cylinder engine's bent axle structure has following beneficial effect: the diameter ratio of the connecting rod shaft diameter to the main journal of the crankshaft structure is greater than 0.9, the ratio of the wall thickness to the cylinder diameter of the crank is greater than 0.2, the connecting part of the connecting rod shaft diameter and the crank is of a fillet structure, and the surface of the connecting rod shaft diameter, the fillet, the root of the crank and the arc surface of the gear mounting shaft are all subjected to quenching treatment, so that the crankshaft structure has the advantages of high strength and small bending deformation.

Drawings

Fig. 1 is a schematic front view of a crankshaft structure according to an embodiment of the present invention;

FIG. 2 is a key slot schematic of a pulley mounting shaft according to an embodiment of the present invention;

fig. 3 is a schematic cross-sectional view of a gear mounting shaft according to an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 1 at I;

fig. 5 is a schematic side view of a crankshaft structure according to an embodiment of the present invention.

Description of the main reference numerals:

100-crankshaft body, 101-belt pulley mounting shaft, 1011-key groove, 102-gear mounting shaft, 1021-circumferential surface, 1022-side vertical surface, 103-main journal, 104-connecting rod shaft diameter, 1041-quenching area, 105-crank, 106-flywheel mounting shaft and 107-balance block.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited by the following detailed description.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

As shown in fig. 1, the crankshaft structure of a single cylinder engine according to the preferred embodiment of the present invention includes a crankshaft body 100, and the crankshaft body 100 includes a pulley mounting shaft 101, a gear mounting shaft 102, a main journal 103, a crank 105, a connecting rod diameter 104, the crank 105, the main journal 103, and a flywheel mounting shaft 106 from one end to the other end again. A pulley mounting shaft 101 is provided at one end of the crankshaft body 100. The connecting rod shaft diameter 104 is arranged between two sections of main journals 103 of the crankshaft body 100, and two ends of the connecting rod shaft diameter 104 are connected with cranks 105. A gear mounting shaft 102 is provided between the pulley mounting shaft 101 and a section of the main journal 103, the gear mounting shaft 102 typically being used to mount timing gears. A flywheel mounting shaft 106 is provided at the other end of the crankshaft body 100 for mounting a flywheel. The diameter ratio of the connecting rod shaft diameter 104 to the main journal 103 in the embodiment is 0.9-0.95, and the ratio of the wall thickness of the crank 105 to the cylinder diameter is 0.2-0.3.

As shown in FIG. 2, in some embodiments, a keyway 1011 is provided in pulley mounting shaft 101, and keyway 1011 is configured to receive a pulley mounting key. Referring to fig. 1, in the present embodiment, a connecting line between the center of the cross section of the key slot 1011 and the center of the pulley mounting shaft 101 coincides with a connecting line between the axis of the connecting rod axis 104 and the axis of the main journal 103, which is favorable for the stress of the crankshaft.

Referring to fig. 3, in some embodiments, two sides of the gear mounting shaft 102 have symmetrical side elevation surfaces 1022, a portion outside the side elevation surfaces 1022 is a circular arc surface 1021, a surface hardness of the circular arc surface 1021 is greater than 50HRC, and a quenching depth is not less than 1 mm. The side elevation 1022 is not required to be quenched due to the small force. Referring to fig. 1, in the present embodiment, a central line of the two arc surfaces 1021 and a line connecting an axis of the connecting rod axis 104 and an axis of the main journal 103 coincide, which is favorable for the stress of the crankshaft.

As shown in fig. 4, in some embodiments, the surface of the connecting rod diameter 104, the junction of the connecting rod diameter 104 and the crank 105, and the root of the crank 105 all need to be quenched and stress relieved. The surface of the connecting rod shaft diameter 104 is provided with a quenching area 1041, the surface hardness of the quenching area 1041 is 50-55HRC, and the quenching depth of the quenching area 1041 at the connecting rod shaft diameter 104 part is not less than 2 mm. The connecting part of the connecting rod shaft diameter 104 and the crank 105 is provided with a fillet, and the radius of the fillet is 2 (0-0.3) mm. The quenching zone 1041 is located at a quenching depth a2 of not less than 1.5mm in the radial direction of 45 degrees of the fillet. The quenching zone 1041 extends to the crank 105 at both ends of the connecting rod shaft diameter 104, and the extending height a1 is not less than 5 mm. In the present embodiment, the surface roughness of the surface of the connecting rod diameter 104, and the surface roughness of the round corner where the connecting rod diameter 104 and the crank 105 are connected is 0.8 μm.

Referring to fig. 5, in some embodiments, the crankshaft structure of the single cylinder engine further includes a balance weight 107 disposed on the crank 105, and the balance weight 107 is located at an end of the crank 105 away from the connecting rod axis 104.

To sum up, the utility model discloses a single cylinder engine's bent axle structure has following advantage: the diameter ratio of the connecting rod shaft diameter to the main journal of the crankshaft structure is greater than 0.9, the ratio of the wall thickness to the cylinder diameter of the crank is greater than 0.2, the connecting part of the connecting rod shaft diameter and the crank is in a fillet structure, and the surface of the connecting rod shaft diameter, the fillet, the root part of the crank and the arc surface part of the gear mounting shaft are all subjected to quenching treatment, so the crankshaft structure has the characteristics of better strength, small bending deformation and good bending and torsion performance of the crankshaft. And the crankshaft has compact structure and large rear-end output power.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. A crankshaft structure of a single cylinder engine, characterized by comprising:

a crankshaft body including;

a pulley mounting shaft provided at one end of the crankshaft body;

the connecting rod shaft diameter is arranged between two sections of main journals of the crankshaft body, and two ends of the connecting rod shaft diameter are connected with cranks;

a gear mounting shaft disposed between the pulley mounting shaft and a section of the main journal; and

a flywheel mounting shaft provided at the other end of the crankshaft body;

the diameter ratio of the connecting rod shaft diameter to the main journal is 0.9-0.95, and the ratio of the wall thickness of the crank to the cylinder diameter is 0.2-0.3.

2. The crankshaft structure of the single cylinder engine as claimed in claim 1, wherein the surface of the connecting rod journal has a quenching zone having a surface hardness of 50-55HRC, the quenching zone being located at a quenching depth of not less than 2mm in the connecting rod journal portion.

3. The crankshaft structure of the single cylinder engine as claimed in claim 2, wherein the connecting rod journal and the crank have a fillet at the junction, and the fillet radius is 2 mm.

4. The crankshaft structure of the single cylinder engine as claimed in claim 3, wherein the quenching depth of the quenching zone in the radial 45 degree direction of the fillet is not less than 1.5 mm.

5. The crankshaft structure of the single cylinder engine as claimed in claim 2, wherein said quenching section extends to said crank at both ends of said connecting rod axial diameter by not less than 5 mm.

6. The crankshaft structure of a single cylinder engine as claimed in claim 1, wherein the two sides of the gear mounting shaft are provided with symmetrical side elevation surfaces, the parts except the side elevation surfaces are circular arc surfaces, the surface hardness of the circular arc surfaces is greater than 50HRC, and the quenching depth is not less than 1 mm.

7. The crankshaft structure for a single cylinder engine of claim 1, wherein said pulley mounting shaft is keyed.

8. The crankshaft structure for a single cylinder engine of claim 1, further comprising a counterbalance mass disposed on said crank, said counterbalance mass being located at an end of said crank remote from said connecting rod axis.