CN214887273U

CN214887273U - Valve mechanism of engine

Info

Publication number: CN214887273U
Application number: CN202120542288.0U
Authority: CN
Inventors: 胡利康; 刘骏鹏; 李奇骅; 许黄玲; 杨萍; 王超
Original assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Current assignee: Sinotruk Jinan Power Co Ltd; China National Heavy Duty Truck Group Jinan Power Co Ltd
Priority date: 2021-03-16
Filing date: 2021-03-16
Publication date: 2021-11-26
Anticipated expiration: 2031-03-16

Abstract

The utility model discloses an engine valve mechanism, including camshaft assembly, rocking arm assembly, valve bridge and electrical system, the camshaft assembly includes camshaft, camshaft gear and camshaft pulse dish, the valve bridge includes into valve bridge and EVB valve bridge, camshaft pulse dish and camshaft gear adjacent installation camshaft tip, the camshaft mid-mounting has exhaust cam and air inlet cam, rocking arm assembly one end and exhaust cam and air inlet cam connection, the other end and into valve bridge and EVB valve bridge connection; the camshaft assembly, the rocker arm assembly and the valve bridge control the valve phase and the valve lift, so that the air inlet, the air exhaust and the EGR in the engine cylinder are realized, and the optimization of the engine performance and the emission level of nitrogen oxides is realized. The utility model discloses an adjustment distribution phase place, cam molded lines and demarcation procedure realize not increasing the cost in the emission of high detonation pressure and high rail pressure condition reduction nitrogen oxide, easy production, and the practicality is strong, the facilitate promotion.

Description

Valve mechanism of engine

Technical Field

The utility model relates to an engine valve actuating mechanism relates to automobile engine technical field.

Background

The market has higher and higher requirements on the oil consumption of the engine, and the increase of the detonation pressure and the rail pressure of the engine is the current mainstream technical means for reducing the oil consumption, but the higher detonation pressure and the higher rail pressure can cause the increase of the emission of nitrogen oxides of the engine. In order to meet the increasingly strict emission regulation requirements, technical means are required to reduce the emission of nitrogen oxides. The technical means of reducing nitrogen oxides in the current mainstream market is to increase an EGR assembly, for the national five-SCR type, the mainstream scheme is adopted, the hardware cost of the engine can be increased, the hardware of the existing national five-SCR engine is greatly changed, and the volume and weight of the engine are increased, so that the trend of being not favorable for light weight is achieved.

Disclosure of Invention

The utility model aims to solve the technical problem that to the defect that prior art exists, a valve timing that reduces nitrogen oxide of adaptation high detonation pressure high rail pressure engine discharges is provided.

In order to solve the technical problem, the utility model provides an engine valve actuating mechanism, including camshaft assembly, rocking arm assembly, valve bridge and electrical system, the camshaft assembly includes camshaft, camshaft gear and camshaft pulse dish, the valve bridge includes into valve bridge and EVB valve bridge, camshaft pulse dish and camshaft gear adjacent installation camshaft tip, the camshaft middle part is installed exhaust cam and the cam that admits air, rocking arm assembly one end with exhaust cam and the cam connection that admits air, the other end with enter valve bridge and EVB valve bridge connection; the exhaust valve is closed before the top dead center of the piston, so that scavenging capacity in the cylinder is guaranteed, and meanwhile, partial exhaust gas is throttled and mixed with intake gas of the next cycle, and exhaust gas recirculation in the cylinder is realized.

The rocker arm assembly comprises an air inlet rocker arm assembly, an air outlet rocker arm assembly, a rocker arm shaft and an adjusting screw, one end of the air outlet rocker arm assembly is connected with an air outlet cam, the other end of the air outlet rocker arm assembly is connected with an EVB valve bridge, the EVB valve bridge is connected with an air outlet valve, and a valve spring is arranged between the EVB valve bridge and the air outlet valve; one end of the air inlet rocker arm assembly is connected with the air inlet cam, the other end of the air inlet rocker arm assembly is connected with an air inlet valve bridge, the air inlet valve bridge is connected with the air inlet valve, and an air valve spring seat is arranged between the air inlet valve bridge and the air inlet valve.

The camshaft pulse disc is provided with a positioning pin hole and seven pulse bulges for controlling the phase of the valve, the camshaft gear is provided with a positioning pin hole and an upper stop mark, and the camshaft is provided with a phase positioning pin hole for transmitting the torque of the camshaft gear and controlling the motion of the valve rocker.

The exhaust cam is provided with a cam profile for exhaust and in-cylinder EGR; the intake cam is provided with an intake cam profile for controlling the opening and closing of the intake valve.

The intake rocker arm assembly is provided with a roller, an adjusting screw and a elephant foot and is used for controlling the valve clearance, and the intake cam controls the opening and closing of the intake valve through the intake rocker arm assembly; the exhaust rocker arm assembly is provided with a roller, an adjusting screw and a elephant foot and is used for controlling the valve clearance, and the exhaust cam controls the opening and closing of the intake valve through the exhaust rocker arm assembly.

The described EVB valve bridge is used to control the opening and closing of two exhaust valves simultaneously and can be used for opening and closing the EVB function.

Has the advantages that: the utility model discloses an EGR technique in the jar realizes that the five engines in state reduce nitrogen oxide emission at high detonation pressure, high rail pressure through the demarcation of control engine. The utility model discloses can be on current valve actuating mechanism basis, through adjustment distribution phase place, cam molded lines and demarcation procedure, realize not increasing the hardware cost of engine at the emission of high detonation pressure and high rail pressure condition decline nitrogen oxide, easily produce, the practicality is strong, the facilitate promotion.

Drawings

Fig. 1 is a schematic mechanism diagram of the present invention;

FIG. 2 is a prior art valve train phase diagram;

fig. 3 is a phase diagram of the valve train of the present invention.

In the figure: 1 camshaft pulse disc, 2 camshaft gears, 3 exhaust cams, 4 camshafts, 5 intake cams, 6 intake rocker arm assemblies, 7 intake valve bridges, 8 valve spring seats, 9 intake valves, 10 exhaust valves, 11 valve springs, 12 exhaust rocker arm assemblies and 13EVB valve bridges; a top dead center, b bottom dead center, c intake valve opening, d intake valve closing, e exhaust valve opening, f exhaust valve closing.

Detailed Description

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

As shown in fig. 1, the utility model provides an engine valve actuating mechanism, including camshaft assembly, rocking arm assembly, valve bridge and electrical system, the camshaft assembly includes camshaft 4, camshaft gear 2 and camshaft pulse dish 1, the valve bridge includes into valve bridge 7 and EVB valve bridge 13, camshaft pulse dish 1 and camshaft gear 2 are adjacent to be installed at camshaft 4 tip, and camshaft 4 mid-mounting has exhaust cam 3 and inlet cam 5, and rocking arm assembly one end is connected with exhaust cam 3 and inlet cam 5, and the other end is connected with intake valve bridge 7 and EVB valve bridge 13; the camshaft assembly, the rocker arm assembly and the valve bridge control the valve phase and the valve lift, so that the air inlet, the air exhaust and the EGR in the engine cylinder are realized, and the optimization of the engine performance and the emission level of nitrogen oxides is realized.

The rocker arm assembly comprises an air inlet rocker arm assembly 6, an exhaust rocker arm assembly 12, a rocker arm shaft and an adjusting screw, one end of the exhaust rocker arm assembly 12 is connected with the exhaust cam 3, the other end of the exhaust rocker arm assembly is connected with an EVB valve bridge 13, the EVB valve bridge 13 is connected with the exhaust valve 10, and a valve spring 11 is arranged between the EVB valve bridge 13 and the exhaust valve 10; one end of the air inlet rocker arm assembly 6 is connected with the air inlet cam 5, the other end of the air inlet rocker arm assembly is connected with the air inlet valve bridge 7, the air inlet valve bridge 7 is connected with the air inlet valve 9, a valve spring seat 8 is arranged between the air inlet valve bridge 7 and the air inlet valve 9, and the air inlet valve bridge 7 controls the opening and the closing of the two air inlet valves simultaneously.

The camshaft pulse disc 1 is provided with a positioning pin hole and seven pulse bulges for controlling the phase of the valve, and the pin hole corresponds to the pin hole on the camshaft and is used for transmitting phase information between the camshaft and the crankshaft; the camshaft gear 2 is provided with a positioning pin hole and an upper stop point a mark, and the pin hole corresponds to a pin hole on the camshaft and is used for phase adjustment observation; the camshaft 4 is provided with a phase positioning pin hole for transmitting the torque of the camshaft gear 2 and controlling the motion of the valve rocker.

The exhaust cam 3 is provided with a cam profile for exhaust and in-cylinder EGR; the intake cam 5 is provided with an intake cam profile for controlling the opening and closing of the intake valve 9.

The intake rocker arm assembly 6 is provided with a roller, an adjusting screw and a elephant foot and is used for controlling the valve clearance, and the intake cam 5 controls the opening and closing of the intake valve 9 through the intake rocker arm assembly 6; the exhaust rocker arm assembly 12 is provided with rollers, adjusting screws and elephant feet for valve clearance control, while the exhaust cam 3 controls the opening and closing of the intake valve 9 through the exhaust rocker arm assembly 12.

The described EVB valve bridge 13 is used to control the opening and closing of both exhaust valves simultaneously and can be used for the opening and closing of the EVB function.

FIG. 2 shows a timing cycle (crankshaft end) of a conventional common five-four stroke diesel engine, in which an intake valve is opened at a point c before a top dead center a of a piston and closed at a point d after a bottom dead center b of the piston, so as to ensure intake charge in a cylinder and achieve the purpose of interference combustion; the exhaust valve is opened at a point e before the lower dead point b of the piston, and the exhaust valve is closed at a point f after the upper dead point a of the piston, so that the scavenging capacity in the cylinder is ensured; through the circulation, the optimization of sufficient air intake charge, exhaust and scavenging in the cylinder is realized, and the purpose of combustion optimization is finally realized.

Fig. 3 shows a valve timing cycle (crankshaft end) of the valve train according to the present invention, in which the intake valve is opened at a point c before the top dead center a of the piston and closed at a point d after the bottom dead center b of the piston, so as to ensure the intake charge in the cylinder; the exhaust valve is opened at a point e before the lower dead point b of the piston, and the exhaust valve is closed at a point f before the upper dead point a of the piston, so that the scavenging capacity in the cylinder is ensured, and simultaneously, a part of exhaust gas is throttled and is mixed with the intake gas of the next cycle, the Exhaust Gas Recirculation (EGR) in the cylinder is realized, the oxygen content in the combustion air of the next cycle is reduced, and the aim of reducing the content of nitrogen oxides generated by the combustion in the cylinder is fulfilled. The circulation realizes air intake, air exhaust, scavenging and EGR in the cylinder, and can realize the combustion at high detonation pressure and high rail pressure and simultaneously balance the emission of nitrogen oxides. Through the mutual cooperation of all parts and an electric control system, the combustion performance and the nitrogen oxide emission of the engine are controlled, and finally the optimization of the performance of the engine and the nitrogen oxide emission level is realized.

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. An engine valve train, characterized by: the device comprises a camshaft assembly, a rocker arm assembly, a valve bridge and an electric control system, wherein the camshaft assembly comprises a camshaft (4), a camshaft gear (2) and a camshaft pulse disc (1), the valve bridge comprises an air inlet valve bridge (7) and an EVB valve bridge (13), the end parts of the camshaft (4) are adjacently installed on the camshaft pulse disc (1) and the camshaft gear (2), an exhaust cam (3) and an air inlet cam (5) are installed in the middle part of the camshaft (4), one end of the rocker arm assembly is connected with the exhaust cam (3) and the air inlet cam (5), and the other end of the rocker arm assembly is connected with the air inlet valve bridge (7) and the EVB valve bridge (13); the exhaust valve is closed before the top dead center of the piston, so that scavenging capacity in the cylinder is guaranteed, and meanwhile, partial exhaust gas is throttled and mixed with intake gas of the next cycle, and exhaust gas recirculation in the cylinder is realized.

2. The engine valve train of claim 1 wherein: the rocker arm assembly comprises an air inlet rocker arm assembly (6), an exhaust rocker arm assembly (12), a rocker arm shaft and an adjusting screw, one end of the exhaust rocker arm assembly (12) is connected with an exhaust cam (3), the other end of the exhaust rocker arm assembly is connected with an EVB valve bridge (13), the EVB valve bridge (13) is connected with an exhaust valve (10), and a valve spring (11) is arranged between the EVB valve bridge (13) and the exhaust valve (10); one end of the air inlet rocker arm assembly (6) is connected with the air inlet cam (5), the other end of the air inlet rocker arm assembly is connected with the air inlet valve bridge (7), the air inlet valve bridge (7) is connected with the air inlet valve (9), and an air valve spring seat (8) is arranged between the air inlet valve bridge (7) and the air inlet valve (9).

3. The engine valve train of claim 1 wherein: the camshaft pulse disc (1) is provided with a positioning pin hole and seven pulse bulges for controlling the valve phase, the camshaft gear (2) is provided with a positioning pin hole and an upper stop mark, and the camshaft (4) is provided with a phase positioning pin hole for transmitting the torque of the camshaft gear (2) and controlling the motion of a valve rocker.

4. The engine valve train of claim 1 wherein: the exhaust cam (3) is provided with a cam profile for exhaust and in-cylinder EGR; the intake cam (5) is provided with an intake cam profile for controlling the opening and closing of the intake valve (9).

5. The engine valve train of claim 2, wherein: the intake rocker arm assembly is provided with a roller, an adjusting screw and a elephant foot and is used for controlling the valve clearance, and the intake cam (5) controls the opening and closing of the intake valve (9) through the intake rocker arm assembly (6); the exhaust rocker arm assembly is provided with a roller, an adjusting screw and a elephant foot and is used for controlling the valve clearance, and meanwhile, the exhaust cam (3) controls the opening and closing of the intake valve (9) through the exhaust rocker arm assembly (12).

6. An engine valve train according to any of claims 1 to 5 wherein: the EVB valve bridge (13) is used for controlling the opening and closing of two exhaust valves simultaneously and can be used for opening and closing an EVB function.