CN218717038U

CN218717038U - Combined camshaft assembly for engine

Info

Publication number: CN218717038U
Application number: CN202222765996.8U
Authority: CN
Inventors: 冯康; 范岚岚; 刘冰; 吕迎波; 季同同
Original assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Current assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2023-03-24
Anticipated expiration: 2032-10-20

Abstract

The utility model discloses a combined camshaft assembly for an engine, which comprises a hollow shaft, wherein an air inlet cam, an exhaust cam and an expansion cam are assembled on the hollow shaft, and the expansion cam is positioned between the air inlet cam and the exhaust cam of a cylinder; the rear end of the hollow shaft is provided with a driving gear and a pulse disc; the exhaust cam at the end has a thrust structure. The utility model discloses simple structure can effectively solve the problem of the processing cost height of current commercial car camshaft for heavy truck, heavy, the function singleness, extra partial shipment, effectively promotes its reliability.

Description

Combined camshaft assembly for engine

Technical Field

The utility model relates to a combination formula camshaft assembly for engine relates to automobile engine technical field.

Background

The camshaft is a main driving part of an engine valve mechanism, and with the continuous development of the internal combustion engine technology, higher requirements are put forward in the aspects of manufacturability, reliability, functionality, flexibility, light weight, low cost and the like. The combined camshaft is different from the traditional integral camshaft, the integral camshaft is integrally forged or cast and then is subjected to heat treatment, rough machining, finish machining, grinding, polishing and the like, at least dozens of working procedures are generally needed for completion, the machining period is long, and the energy consumption is large. The application of the combined camshaft can effectively improve the performance. The combined camshaft is widely applied to small-displacement engines of passenger vehicles, and with the maturity of the combined camshaft technology, combined camshafts are developed by mainstream commercial vehicle heavy truck enterprises in recent years. However, the camshaft on the existing commercial vehicle heavy truck engine mainly has the following problems: 1) The integral camshaft is limited by a forging or casting process, and the number, the spacing and the positions of the cams cannot be flexibly selected; 2) The cam of the integral cam shaft only can be made of the same material as the cam body, and the material can not be optimally matched according to the requirement; 3) The integral camshaft needs to be separately assembled with a driving gear, a pulse disc and the like through bolts, so that the number of parts is increased, and an additional separate assembly process is needed; 4) The shaft neck of the combined camshaft needs to be ground after quenching, the structure with the thrust ring needs to be additionally assembled, and the assembly process and the assembly cost are increased.

Disclosure of Invention

The utility model aims to solve the technical problem that to the defect that prior art exists, a combination formula camshaft assembly for engine is provided.

In order to solve the technical problem, the utility model provides a combined camshaft assembly for engine, which comprises a hollow shaft, wherein an air inlet cam, an exhaust cam and an expansion cam are assembled on the hollow shaft, and the expansion cam is positioned between the air inlet cam and the exhaust cam of a cylinder; the rear end of the hollow shaft is provided with a driving gear and a pulse disc; the exhaust cam at the end has a thrust structure.

The side surface of the exhaust cam at the end part facing the driving gear is designed with a thrust structure; and the thrust structure and the end surface of the adjacent driving gear are provided with thrust surfaces.

The driving gear and the pulse disc are of an integrated structure, and are formed by forging a blank from an alloy steel material and then machining the blank.

The driving gear is provided with a timing mark, and the signal teeth and the timing mark of the pulse disc ensure correct angular positions.

The expansion cam can be used as a brake cam or a Miller cam or an oil pump cam, and each cylinder at least comprises one expansion cam according to the functional requirements of the engine.

And a journal which is directly formed by grinding is arranged on the hollow shaft between the air inlet cam and the exhaust cam of the adjacent cylinder.

The air inlet cam, the air exhaust cam and the expansion cam are made of bearing steel or powder metallurgy materials, the hollow shaft is made of cold-drawn seamless steel tubes, knurling is formed on the surface of the hollow shaft, and interference assembly of all the cams is completed in sequence.

The air inlet cam, the air outlet cam and the expansion cam are fixed on the hollow shaft in a mechanical tensioning connection mode, a hydraulic tensioning connection mode, a sintering connection mode, a knurling connection mode or a hot sleeve connection mode; the driving gear and the pulse disc are fixed on the hollow shaft in a knurling connection mode or a hot sleeve connection mode.

Has the advantages that: the utility model has the advantages that the cams are assembled with the hollow shaft, the width and the space of the cams are not limited by the casting or forging process, and the number and the positions of the cams can be flexibly selected according to requirements; because the cam and the hollow shaft are assembled together, parts can flexibly select different materials so as to realize optimal matching and obtain better performance; the hollow shaft adopts a cold-drawn steel pipe, so that the weight of the assembly can be obviously reduced; the cam is prefabricated into a thin-wall part, so that the heat treatment time can be effectively reduced; the driving gear and the pulse disc are integrally designed, so that the number of parts can be reduced, and additional assembly procedures can be reduced; the quenching process is omitted from the camshaft journal, so that the processing process can be reduced; and a thrust ring structure is eliminated, so that the number of parts is reduced, and additional assembly procedures are reduced. The utility model discloses simple structure can effectively solve the problem of the processing cost height of current commercial car camshaft for heavy truck, heavy, the function singleness, extra partial shipment, effectively promotes its reliability.

Drawings

Fig. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic sectional view of the present invention.

In the figure: 1. a hollow shaft; 2. an intake cam; 3. an exhaust cam; 4. an expansion cam; 5. a drive gear; 6. a pulse disk; 7. a journal; 8. and a thrust structure.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples.

As shown in fig. 1 and fig. 2, the present invention provides an assembled camshaft assembly for an engine, including a hollow shaft 1, an intake cam 2, an exhaust cam 3 and an expansion cam 4 are assembled on the hollow shaft 1, and in an example of the assembled camshaft assembly for a six-cylinder engine, six intake cams 2, six exhaust cams 3 and six expansion cams 4 are assembled on the hollow shaft 1; the expansion cam 4 is positioned between the air inlet cam 2 and the air outlet cam 3 of the cylinder, and the assembly position of the expansion cam 4 is close to the air outlet cam 3 due to the arrangement of the air outlet valve and the air distribution mechanism needing to be opened; the rear end of the hollow shaft 1 is provided with a driving gear 5 and a pulse disc 6; the exhaust cam 3 at the end is provided with a thrust structure 8; the exhaust cam 3 with the thrust structure 8 can be realized by adjusting the mould correspondingly in the prefabrication stage.

The side of the exhaust cam 3 of the end part facing the drive gear 5 is designed with a thrust structure 8; the thrust structure 8 and the adjacent end face of the driving gear 5 are provided with thrust faces.

The driving gear 5 and the pulse disc 6 are of an integrated structure, and are formed by forging a blank from an alloy steel material and then machining the blank.

The drive gear 5 is provided with a timing mark, and the signal teeth and the timing mark of the pulse disk 6 ensure correct angular positions.

The expansion cam 4 can be used as a brake cam or a miller cam or an oil pump cam, and each cylinder at least comprises one expansion cam 4 according to the functional requirements of the engine. When the expansion cam 4 is used as a brake cam, the independent brake rocker arm can be driven, and the brake power of the engine is improved; when the expansion cam 4 is used as the Miller cam, the independent air inlet rocker arm can be driven, and the heat efficiency of the engine is improved; when the expansion cam 4 is used as an oil pump cam, an independent single pump rocker arm can be driven to provide appropriate fuel pressure.

The hollow shaft 1 between the air inlet cam 2 and the exhaust cam 3 of the adjacent cylinder is provided with a shaft neck 7 which is directly formed by grinding, induction quenching is not needed, the processing technology is simplified, and meanwhile, the weight is also reduced.

The air inlet cam 2, the air outlet cam 3 and the expansion cam 4 are made of bearing steel or powder metallurgy materials, the hollow shaft 1 is made of cold-drawn seamless steel tubes, knurling is arranged on the surface of the hollow shaft 1, and interference assembly of all the cams is completed in sequence.

The air inlet cam 2, the air outlet cam 3 and the expansion cam 4 are fixed on the hollow shaft 1 in a mechanical tensioning connection mode, a hydraulic tensioning connection mode, a sintering connection mode, a knurling connection mode or a shrink fit connection mode; the driving gear 5 and the pulse disk 6 are fixed on the hollow shaft 1 by knurling connection or shrink-fit connection.

The utility model combines the separately prepared cam, the driving gear and the pulse disc in a matching way and then assembles the cam disc to the hollow shaft to form a combined cam shaft assembly, and each cylinder is provided with at least one expansion cam according to the function requirement except an air inlet cam and an exhaust cam; the driving gear and the pulse disc are integrally designed, so that the number of parts can be reduced, and the assembly weight can be obviously reduced because the hollow shaft adopts a cold-drawn steel pipe; the cam is prefabricated into a thin-wall part, so that the heat treatment time can be effectively reduced; the utility model expands the design space of single cylinder, and can increase the expansion function of independent cam according to the requirement; the utility model discloses the problem of the existing commercial car camshaft for heavy truck's processing cost height, heavy, function singleness, extra partial shipment has effectively been solved.

The cam of the utility model adopts prefabricated thin-wall parts, can be selected according to the requirements of the number and the functions of each cylinder cam, except configuring the conventional air inlet cam and the conventional exhaust cam, the position relation, the width, the material and the like of other extension cams can be flexibly selected according to the requirements, for example, the Miller cam can be designed according to the requirements to meet the requirement that the air inlet lift is variable; because the cam can be integrated with a thrust structure and combined with the adjacent driving gear to form a thrust surface, additional thrust ring parts are not needed, the assembly process is effectively simplified, and the number of parts is reduced; the cam, the driving gear, the pulse disc and other parts adopt the mature processes of knurling connection, hot sleeve connection and the like, so that the function of the whole combined camshaft assembly is more perfect, and the reliability is further improved.

The above embodiments of the present invention are merely examples, not the only ones, and all changes within the scope of the present invention or the same range of the present invention are all surrounded by the present invention.

Claims

1. The utility model provides a combination formula camshaft assembly for engine which characterized in that: the exhaust device comprises a hollow shaft (1), wherein an air inlet cam (2), an exhaust cam (3) and an expansion cam (4) are assembled on the hollow shaft (1), and the expansion cam (4) is positioned between the air inlet cam (2) and the exhaust cam (3) of a cylinder in which the expansion cam (4) is positioned; the rear end of the hollow shaft (1) is provided with a driving gear (5) and a pulse disc (6); the end exhaust cam (3) is provided with a thrust structure (8).

2. The assembled camshaft assembly for an engine as set forth in claim 1, wherein: the side surface of the exhaust cam (3) at the end part facing the driving gear (5) is provided with a thrust structure (8); thrust surfaces are machined on the end faces of the thrust structure (8) and the adjacent driving gear (5).

3. The assembled camshaft assembly for an engine as set forth in claim 1, wherein: the driving gear (5) and the pulse disc (6) are of an integrated structure, and are formed by forging a blank from an alloy steel material and then machining the blank.

4. The assembled camshaft assembly for an engine as set forth in claim 1, wherein: the driving gear (5) is provided with a timing mark, and the signal teeth and the timing mark of the pulse disc (6) ensure correct angular positions.

5. The assembled camshaft assembly for an engine as set forth in claim 1, wherein: the expansion cam (4) can be used as a brake cam or a Miller cam or an oil pump cam, and each cylinder at least comprises one expansion cam (4) according to the functional requirements of the engine.

6. The assembled camshaft assembly for an engine as set forth in claim 1, wherein: and a shaft neck (7) which is directly formed by grinding is arranged on the hollow shaft (1) between the air inlet cam (2) and the exhaust cam (3) of the adjacent cylinder.

7. The assembled camshaft assembly for an engine as set forth in claim 1, wherein: the air inlet cam (2), the exhaust cam (3) and the expansion cam (4) are made of bearing steel or powder metallurgy materials, the hollow shaft (1) is made of cold-drawn seamless steel tubes, knurling is formed on the surface of the hollow shaft (1), and interference assembly of all the cams is completed in sequence.

8. The assembled camshaft assembly for an engine according to any one of claims 1 to 7, wherein: the air inlet cam (2), the exhaust cam (3) and the expansion cam (4) are fixed on the hollow shaft (1) in a mechanical tensioning connection mode, a hydraulic tensioning connection mode, a sintering connection mode, a knurling connection mode or a hot sleeve connection mode; the driving gear (5) and the pulse disc (6) are fixed on the hollow shaft (1) in a knurling connection mode or a shrink fit connection mode.