CN2760233Y

CN2760233Y - A gas distribution camshaft for highly supercharged diesel engine

Info

Publication number: CN2760233Y
Application number: CN 200420056874
Authority: CN
Inventors: 王宏生; 李长清
Original assignee: TIANDONG TECHNOLOGY CENTER TIANJIN CITY
Current assignee: TIANDONG TECHNOLOGY CENTER TIANJIN CITY
Priority date: 2004-12-21
Filing date: 2004-12-21
Publication date: 2006-02-22
Anticipated expiration: 2014-12-21

Abstract

The utility model provides an air distribution camshaft for a highly supercharged diesel engine, which is characterized in that shaft steps are evenly distributed on a shaft body; a pair of cams which drives an air inlet valve to open and close and a pair of cams which drives an exhaust valve to open and close are arranged on the shaft body between every two shaft steps; the included angle alpha of the position of each pair of cams is equal to 87DEG, and the centre angle beta which corresponds to a lift range contour line of each cam is equal to 180DEG, so that the air inlet valve is opened through 53DEG before an upper dead point and closed through 47DEG after a lower dead point, and the exhaust valve is opened through 47DEG before the lower dead point and closed through 53DEG after the upper dead point. The utility model has the advantages that the scavenging performance of a combustion chamber of the diesel engine is improved, the work efficiency of the diesel engine is enhanced, the exhaust temperature is reduced, and the exhaust pollution is reduced.

Description

A kind of high pressure-charging diesel engine distribution cam axle

Technical field

The utility model relates to a kind of diesel engine that is used for engineering machinery, especially a kind of high pressure-charging diesel engine distribution cam axle.

Background technique

It is big that diesel engine has power, and therefore economic advantage is widely used in engineering machinery such as loader, bulldozer, diesel generator.The diesel engine camshaft timing is generally:

Inlet open is closed in after bottom dead center 47 ° in piston 13 ° of piston before top dead center;

Exhaust valve opening is closed in 13 ° of piston after top dead center in BBC 47 ° in piston;

Wherein air inlet and exhaust valve keying overlapping angle is 26 °.

Diesel engine generally adopts high pressure-charging at present, improved supercharging level, thereby the camshaft that shows former diesel engine port timing has not been suitable for the high pressure-charging diesel engine, though the power of diesel engine can be brought up to 196kW when 1500r/min, power increases to original 1.78 times, at the end exhaust gas pressure is higher but owing to exhaust, and the air inlet and exhaust valve overlapping angle of camshaft is too small, therefore waste gas is discharged not smooth, residual gas is more, and then has influence on required normal air inflow of diesel engine and emissions of diesel engines performance, causes fuel combustion not thorough, the fuel consume height, the problem that excessive discharge temperature and exhaust emission exceed standard.

Summary of the invention

The utility model provides a kind of emission performance that realizes good for solving the technical problem that exists in the known technology, the high pressure-charging diesel engine distribution cam axle that efficient is high.

The technological scheme that the utility model is taked for the technical problem that exists in the solution known technology is:

A kind of high pressure-charging diesel engine distribution cam axle, by the axis body that drives by cylinder piston connecting rod crank and gear driving member that is installed in cylinder one side, axially uniform on axis body the pillow block rank, be prepared in the cam that the driving suction valve in the rotating shaft opens and closes between each pillow block rank and drive the cam that outlet valve opens and closes and forms, described driving suction valve open and close cam cross the summit center line with drive outlet valve open and close cam the axis projection angle of summit center line be α=87 °; The central angle of the lift profile line correspondence of described each cam is β=180 °.

Advantage and the good effect that the utlity model has are: because the axis projection angle that will drive between suction valve keying cam and the driving outlet valve keying cam is changed system into 87 °, the central angle of each cam lift section correspondence is changed system into 180 °, strengthened the air inlet and exhaust valve overlapping angle, promptly increase to 106 ° by original 26 °, it is happy that the motor indoor exhaust air is discharged, improved the scavenging performance of diesel engine firing chamber, reduced the residual gas amount in the firing chamber, make fuel combustion more abundant, improved the efficient of diesel engine widely, reduced the fuel consumption rate (being reduced to 218g/kWh) of diesel engine by original 245g/kWh; The utility model also has reduction delivery temperature (being reduced to 500 ℃ by original 580 ℃) and reduces the advantage of exhaust emission (the exhaust emission value is in the GB scope) in addition.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is 12 cam position schematic representation among Fig. 1;

Fig. 3 is the cam profile schematic representation;

Fig. 4 is cam lifting curve figure;

Fig. 5 is a valve timing diagram of the present utility model.

Embodiment

For further understanding summary of the invention of the present utility model, characteristics and effect, exemplify following examples now, and conjunction with figs. is described in detail as follows:

The camshaft that sees also Fig. 1 is one six a cylinder diesel engine camshaft, axis body 14 is a major axis, uniformly on axis body be shaped on seven pillow block rank 13, on the axis body between each pillow block rank, be shaped on six pairs of driving suction valves cam that opens and closes and the

cam

1 and 2,3 and 4,5 and 6 that drives the outlet valve keying respectively, 7 and 8,9 and 10,11 and 12, their circumferential locations distributes as shown in Figure 2.Wherein each is to cam 1,2, cam 3,4, and

cam

5,6,

cam

7,8, the circumferential position angle α of

cam

9,10 and

cam

11,12 is 87 °; The central angle β of the lift profile line correspondence of each cam is 180 °, as shown in Figure 3, the lift of cam and cam angle coordinate curve as shown in Figure 4, wherein a is former cam lifting curve, b is for improving the back cam lifting curve.Can improve the port timing of camshaft like this, realize increasing air inlet and exhaust valve and open and close overlapping angle.Camshaft timing after the improvement is:

Inlet open is closed in after bottom dead center 47 ° in piston 53 ° of piston before top dead center;

Exhaust valve opening is closed in 53 ° of piston after top dead center in BBC 47 ° in piston;

Wherein air inlet and exhaust valve keying overlapping angle is 106 °, and the realization suction valve is opened in advance, and the distribution effect that outlet valve lags behind and closes as shown in Figure 5, has improved the scavenging performance of diesel engine firing chamber greatly.

Claims

1. high pressure-charging diesel engine distribution cam axle, by the axis body that drives by cylinder piston connecting rod crank and gear driving member that is installed in cylinder one side, axially uniform on axis body the pillow block rank, be prepared in the cam that the driving suction valve in the rotating shaft opens and closes between each pillow block rank and drive the cam that outlet valve opens and closes and forms, it is characterized in that: described driving suction valve open and close cam cross the summit center line with drive outlet valve open and close cam the axis projection angle of summit center line be α=87 °; The central angle of the lift profile line correspondence of described each cam is β=180 °.