DE19829857A1 - Internal combustion engine with a pneumatic and / or hydraulic actuator for a gas exchange valve - Google Patents

Abstract

For an internal combustion engine with a pneumatic and / or hydraulic actuator for a gas exchange stroke valve, which can be controlled via a piston which can be acted upon on both sides in a control chamber and the control spaces on both sides of the piston are supplied or disposed of via lines controlled by solenoid valves, the achievement is higher Switching frequencies of the actuator proposed that electromagnetically controlled coaxial valves serve as solenoid valves and these are arranged such that the filling and emptying is effected by means of a single line to each control chamber.

Description

According to the preamble of claim 1, the invention relates to a Internal combustion engine with a pneumatic and / or hydraulic actuator for a gas exchange lift valve, the lift valve with a shaft over its shaft a control chamber with pistons that can be acted upon on both sides in drive connection stands, and the control rooms on both sides of the piston with lines in connection stand, which are controlled by solenoid valves.

A pneumatically operated valve control for internal combustion engines in combination with a mechanical return spring is for example from DE-A 41 32 891 known, the supply and discharge of the pressure medium via electrically controlled Valves is effected.

Furthermore, a hydraulic valve control is known from DE-A 195 15 142, at the the supply and discharge lines of the hydraulic pressure medium from the tax are controlled on both sides of the piston by solenoid valves.

Because especially in Otto internal combustion engines with relatively high speeds in pneumatic or hydraulic actuators to the respective pressure medium quickly  quick-acting valves are required for this Lich.

The invention is based on the object for a generic actuator for the control / reversal of large quantities of the respective print medium or Propose flow medium quick acting solenoid valve with a club fold arrangement of lines for supplying and discharging the respective stream medium.

This object is achieved with claim 1 in that as solenoid valves Serve electromagnetically controlled coaxial valves and arranged them in this way are that by filling a single line to each control room and Emptying is effected.

With the selection according to the invention of electromagnetic coaxial valves in Connection with the simplified line arrangement is advantageously a achieved relatively simple structure of the respective actuator.

In a preferred embodiment of the invention, a pneumatic actuator is selected the one with the front of the internal combustion engine in the area of the omitted cam shaft drive arranged on a crankshaft compressed air pump under intermediate circuit of a compressed air reservoir arranged in the cylinder head in connection stands.

The arrangement described above is advantageous for internal combustion engines by a mechanical gas exchange valve control on a pneumatic or hy drastic control must be converted.

The invention is based on an embodiment shown schematically in the drawing Example described. It shows  

Fig. 1 is a pneumatic and / or hydraulic actuator for a gas exchange lifting valve of an internal-combustion engine,

Fig. 2 shows a section along the line II-II in Fig. 1 and

Fig. 3 shows a compressed air system in an internal combustion engine for pneumatic actuators.

An internal combustion engine 23 , not shown, is preferably equipped with a pneumatic actuator 4 for a gas exchange globe valve 2 . The stroke valve 2 is in drive connection via its shaft 2 'with a piston 1 which can be acted upon on both sides in a control chamber 3 . The piston 1 divides the control chamber 3 into the control rooms 3 ′ and 3 ″, the control room 3 ′ being connected to a line 15 and the control room 3 ″ according to FIG. 2 being connected to a line 18 . Solenoid valves 5 and 6 are used to control lines 15 and 18 .

In order to achieve a safe filling and emptying of the control rooms 3 'and 3 ''in view of high speeds, especially in Otto engines, he is proposed according to the invention that electromagnetically controlled coaxial valves 5 and 6 serve as solenoid valves and these are arranged such that by means of a single line 15 or 18 to each control chamber 3 'or 3 ''filling and emptying is effected.

The control chamber 3 can be a component of the actuator 4 , in which the electromagnetically controlled coaxial valves 5 and 6 are also arranged. In Zy cylinder head 9 the control chamber 3 adjacent longitudinal channels 7 and 8 are assigned, the longitudinal channel 7 of the compressed air supply and the longitudinal channel 8 of the compressed air discharge. With the compressed air longitudinal channel 7 , a compressed air supply channel 10 is connected in the actuator, which supplies two coaxial valves 5 and 6 with compressed air. With the longitudinal channel 8 for compressed air discharge in the actuator, the compressed air channel 11 is connected via the valve-controlled, the respective compressed air flows out into the longitudinal channel 8 .

Compressed air is always present in the supply duct 10 . The air flows into the longitudinal bore 8 via the disposal duct 11, from there, depending on the valve, from there via holes 12 into the inlet or exhaust duct 13 in the cylinder head 9 .

In Fig. 1 the opening of the valve 2 is shown. An armature 14 of the coaxial valve 5 is in the lower position, so that compressed air can flow via the channels 10 and 15 into the control chamber 3 above the piston 1 , while the disposal channel 16 of the coaxial valve 5 is closed.

An armature 17 of the coaxial valve 6 is in the upper position and closes the compressed air supply, while the air below the piston 1 can escape from the control chamber 3 ″ via the disposal channels or lines 18 , 19 and 11 .

To close the lift valve 2 , compressed air is fed into the lower control chamber 3 ″ via the line 18 and the upper coaxial valve 6 from the compressed air duct 10 , the lower coaxial valve 5 in the open position, the compressed air flowing out via the lines 15 and 16 into the disposal duct 11 leaves.

The internal combustion engine 23 shown in Fig. 3 is frontally equipped in the region of the camshaft drive ent with an air pump 20 arranged on the crankshaft 21 , which is connected to the compressed air reservoir 22 with the compressed air supply channel 7 in connection with the interposition of a compressed air reservoir 22 in the cylinder head 9 .

Claims (2)

1. Internal combustion engine with a pneumatic and / or hydraulic actuator for a gas exchange valve

• - Wherein the lift valve ( 2 ) via its shaft ( 2 ') with a in a control chamber ( 3 ) on both sides acted upon piston ( 1 ) in drive connection, and
• - The control rooms ( 3 ', 3 '') on both sides of the piston ( 1 ) are connected to lines ( 15 , 18 ) which
• - are controlled by means of solenoid valves ( 5 , 6 ),

characterized by

• - That electromagnetically controlled coaxial valves ( 5 , 6 ) serve as solenoid valves and are arranged in such a way
• - That by means of a single line ( 15 , 18 ) to each control room ( 3 ', 3 '') the filling and emptying is effected.

2. Internal combustion engine according to claim 1, characterized in that a pneumatic actuator ( 4 ) is provided, the

• - With a front side of the internal combustion engine ( 23 ) in the area of the camshaft drive omitted on a crankshaft ( 21 ) angeord Neten compressed air pump ( 20 ) with the interposition of an in the cylinder head ( 9 ) arranged compressed air reservoir ( 22 ) in connection.