CN1276038A - Device for actuating gas exchange valves of piston-type internal combustion engines - Google Patents

Abstract

The invention relates to a device for actuating gas exchange valves of a reciprocating piston internal combustion engine, comprising an electromagnetic actuator for actuating the same, which has a closing electromagnet and an opening electromagnet, between which an armature is mounted so as to be axially displaceable, which acts on a valve stem via an armature rod mounted in a guide device and via a spring system, wherein the armature rod is formed by a tube, and the device comprises a play compensation element which is connected via the armature rod to a pressure connection for supplying a pressure medium. In order to create a device for actuating gas exchange valves of a reciprocating piston engine, which has a low weight with sufficient load capacity, it is proposed according to the invention that the armature rod has regions with different wall thicknesses for the load.

Description

Devices for operating gas exchange valves for piston-type internal combustion engines

The invention relates to a device for actuating a gas exchange valve of a piston-type internal combustion engine according to the preamble of claim 1 .

A known device of this type for actuating the gas exchange valve is known from the past patent application DE 19728479.5-13, wherein the gas exchange valve is actuated by an electromagnetic actuator. The actuator has two actuating solenoids which hold the gas exchange valve in an open and a closed position. An armature is arranged axially displaceable between the two actuating solenoids, which acts on the valve stem of the gas exchange valve together with a spring system via an armature rod mounted in the guide. When the operating electromagnet is not energized, the armature is held in an equilibrium position by a spring system, which preferably coincides with the center of energy between the operating electromagnets.

Dimensional changes not accounted for from the start or over time, such as machining errors of individual parts or thermal deformation of different materials, can lead to a discrepancy between the equilibrium position of the armature and the position of the center of energy between the operating solenoids. This can result in the armature no longer resting completely on the abutment or pole face of the electromagnet, a gap forming between the armature rod and the valve rod and/or the gas exchange valve no longer closing completely. In order to compensate for this changing dimension, the device has a play compensator arranged between the armature rod and the valve rod, which is connected via the armature rod to a pressure connection for supplying pressure medium. For this purpose, the armature rod has a longitudinal channel, which can be connected to a pressure connection.

The object of the invention is to create a device for actuating a gas exchange valve which is light in weight with sufficient load-carrying capacity.

This object is achieved according to the invention by the features specified in the characterizing part of claim 1 .

A distinct advantage of the invention is that the device is of particularly light construction. The armature rod is formed from a tube, which leads to a considerable saving of material and thus also a reduction in weight. The tubular armature rod has regions of different wall thicknesses which are adapted to the respective load acting on these regions. As a result, the armature rod can be made as light as possible without failing under load. The mass of the moving parts of the device can thus be kept relatively small. With the same spring stiffness of both compression springs, this results in a shortened flight time (oscillating time) of the armature, which means an advantageously longer opening time of the valve. This advantageously results in sufficient intake air and thus high efficiency at high internal combustion engine speeds. In the case of reducing the spring stiffness of the compression spring while keeping the flight time of the armature constant, only a small holding force of the actuating electromagnet is required, which leads to a reduction in energy consumption. In addition, the tube produced by drawing or continuous pressing has high rigidity and high strength, so that the hollow armature rod can have sufficient load-bearing capacity.

The device has a play compensator arranged between the armature rod and the valve rod, the hollow armature rod can additionally be used for the pressure medium supply of the play compensator. The additional machining effort required for machining a separate pressure medium channel on the armature rod is eliminated. A tubular armature rod produced by drawing or continuous pressing has a higher rigidity and strength than a solid armature rod provided with subsequently processed pressure medium channels. The tubular armature rod is preferably closed by pressing in a plug to form the pressure medium reservoir, whereby the entire interior of the tube can be used as a reservoir and the final size of the reservoir can be varied depending on the position of the plug. Other closing possibilities, such as welding, can also be considered.

An armature rod mounted in a guide is connected to the pressure connection via a bore. In a further development of the invention, a constriction is provided in the region of the armature rod bore, which forms an annular groove with the armature rod guide, through which the bore is connected to the pressure connection. The formation of the annular groove for conveying the pressure medium does not interrupt the fiber distribution of the tube other than the bore, so that a completely unimpeded flow of force is possible in the course of the armature rod.

Further structures and advantages of the invention emerge from the remaining subclaims and the description.

An exemplary embodiment is shown in more detail below together with further details in the single figure. It represents a device indicated overall by 1 for actuating a gas exchange valve 2 of a piston internal combustion engine not shown in detail. The ventilation valve 2 has a valve stem 2 and a valve disk 4, wherein the valve disk 4 interacts with a valve seat 5 arranged in a ventilation channel (not shown here) and serves to close the ventilation channel. The device 1 is used to operate a gas exchange valve 2, wherein the gas exchange valve 2 can be moved back and forth between a closed position shown in the figure and an open position.

The device 1 has an electromagnetic actuator 6 for actuating the gas exchange valve 2, which is accommodated in a bore 7 of a component 8 of the internal combustion engine. The actuator 6 has a closing electromagnet 9 at the top and an opening electromagnet 10 at the bottom, and an armature 13 movable along the longitudinal axis 14 of the gas exchange valve 2 is arranged between their pole faces 11 , 12 . When the internal combustion engine is in operation, the armature 13 rests alternately with its working surfaces 15 , 16 on the pole surfaces 11 , 12 of the actuating electromagnets 9 , 10 and is held in two separate switching positions by the electromagnets 9 , 10 .

The armature 13 is fastened on an armature rod 17 , for example pressed onto it. According to the invention, the armature rod 17 is formed by a tube in order to reduce the weight, wherein the tube 17 runs in a guide 18 installed in the opening electromagnet 10 . The tubular armature rod 17 has a constriction 20 in the region 19 of the guide 18 and a thread 21 at the end facing away from the electromagnets 9 , 10 . The armature 13 acts via this armature rod 17 on the valve stem 3 and thus on the valve disk 4 of the ventilation valve 2 closing the ventilation channel. The valve rod 3 is likewise mounted displaceably in the direction of the longitudinal axis 14 , ie in the opening direction 14 a and in the closing direction 14 b of the gas exchange valve 2 .

The opening electromagnet 10 is supported in the bore 7 in the direction of the gas exchange valve on a washer 22 and on an abutting ring 23 fastened to the housing. Between the actuator 6 and the valve disk 4 the arrangement has a spring system 24 consisting of an upper valve spring 25 acting in the opening direction 14a and a lower valve spring 26 acting in the closing direction. Both the opening spring 25 and the closing spring 26 are designed as helical springs in the exemplary embodiment shown. The upper valve spring 25 is supported in the direction of the gas exchange valve 2 on a spring seat 27 screwed on the thread 21 of the armature rod 17, and in the direction facing away from the gas exchange valve 2 on a washer attached to the opening electromagnet 10 22 on. The lower valve spring 26 is supported on the component 8 in the direction of the gas exchange valve 2 and in the direction facing away from the gas exchange valve 2 on a spring seat 28 fastened to the valve rod 3 . The valve springs 25 , 26 are pretensioned in such a way that the armature 13 remains in an equilibrium position when the actuating solenoids 9 , 10 are not energized, which preferably corresponds to the midpoint of energy between the actuating solenoids 9 , 10 .

Either one of the two electromagnets 9, 10 is overexcited for a short time when the actuator 6 is started, so that the armature 13 is sucked away from the equilibrium position, or the armature 13 vibrates with its resonance frequency through a shock-starting program, so that it moves toward the One pole face 11 , 12 of the actuating electromagnet 9 , 10 is moved and held there. In the closed position of the gas exchange valve, as shown in the figure, the armature 13 rests with its first working surface 15 on the pole surface 11 of the energized closing electromagnet 9 and is attracted thereto. Closing the electromagnet 9 pretensions the upper valve spring 25 acting in the opening direction 14a. In order to open the ventilation valve 2, close the electromagnet 9 and de-energize it. The valve spring 25 acting in the opening direction 14a accelerates the armature 13 and moves it beyond the equilibrium position in the direction of the open position of the gas exchange valve 2 . Connect and open the electromagnet 10 before reaching the opening position, so that the armature 13 is attached to the pole face 12 of the opening electromagnet 10 with its second working surface 16, and is sucked firmly by it. In order to close the ventilation valve 2 again, at this moment the valve disc 4 fits on the valve seat 5 and closes the ventilation channel, and the opening electromagnet 10 is turned off. The valve spring 26 acting in the closing direction 14b accelerates the armature 13 and moves it beyond the equilibrium position towards the closing electromagnet. The armature 13 is attracted by the closing electromagnet that is turned on during this period, and sticks on the pole face 11 of the closing electromagnet 9 with its working surface 15 and is sucked firmly by it.

During operation of the internal combustion engine, both "positive" valve play and "negative" valve play can occur, wherein "negative" valve play means that the valve can no longer close correctly. Therefore, in order to compensate the valve play to achieve a play-free operation of the valve actuator, a hydraulic play compensation element 29 is provided, which is clamped between the armature rod 17 and the valve stem 3 by the pretension of the valve springs 25, 26, where the play compensation Element 29 may be built into spring seat 28 of lower valve spring 26 or, as shown, in spring seat 27 of upper valve spring 25 . If now there is a gap between the inner armature rod 17 and the valve stem 3, the working face 15 of the armature 13 is no longer in full contact with the pole face 11 of the operating electromagnet 9 or is no longer completely closed, for example the gas exchange valve 2, then the gap compensating element 29 Compressed by the active force of the spring 26 until the gas exchange valve 2 rests on the valve seat 5 with its valve disk 4 .

The tubular armature rod 17 can advantageously additionally be used to supply a hydraulic play compensating element 29 with pressure medium, wherein the play compensating element 29 is connected to the pressure connection via the hollow armature rod 17 . By forming the armature rod 17 from a tube, a separate channel for the supply of pressure medium can be dispensed with. The tube 17 has load-resistant regions 31 to 33 of different wall thicknesses, which in the exemplary embodiment comprise the region 31 of the thread 21 , the region 32 of the constriction 20 and the rest of the armature rod 17 . To form a reservoir 34 for the pressure medium, the tubular armature rod 17 is closed by a plug 35 pressed into the area 32 of the constriction 20 , wherein the plug 35 can be positioned according to the desired size of the reservoir.

The pressure medium is input from the pressure connection pipe 30 below the electromagnet 10 through the annular grooves 36 distributed in the ring 23 . In the ring 23 the pressure medium is supplied via the annular groove 36 to a channel 37 in the washer 22 , through which the pressure medium reaches the bore 38 arranged in the opening electromagnet 10 . The bore 38 is connected to a channel 39 provided in the guide 18 of the armature rod 17 and leads to a further annular groove 40 formed by the constriction 20 of the armature rod 17 and the guide 18 . In the region of the annular groove 40 the armature rod 17 has a bore 41 through which pressure medium enters the interior of the tubular armature rod 17 or the reservoir chamber 34 and thus enters the play compensating element 29 .

Claims (8)

1. be used for the device of operating gas shuttle valve of reciprocating internal combustion engine (2), electromagnetic actuators (6) with an operation scavenging air valve, it has one to close electromagnet (9) and a unlatching electromagnet (10), an armature (13) axially movably is installed between them, it is installed on the valve rod (3) that armature lever (17) in the guide device (18) and a spring system (24) act on scavenging air valve (2) together by one, wherein armature lever (17) is made of pipe, and device (1) has a gap compensating part (29), it is connected with a pressure connection tube (30) to supply with pressure medium by armature lever (17), it is characterized in that: armature lever (17) has the zone (31 at load of different wall, 32,33).

2. by the device of claim 1, it is characterized in that: armature lever (17) has screw thread (21) on the end of two electromagnet (9,10) dorsad at it.

3. by the device of claim 1 or 2, it is characterized in that: armature lever (17) is closed (stopper 35) storage chamber (34) to form a pressure medium, and is connected with pressure connection tube (30) by hole (41).

4. press the device of claim 3, it is characterized in that: be provided with a constriction (20) in the zone in the last hole (41) of armature lever (17), the guide device (18) of it and armature lever (17) constitutes a circular groove (40), and hole (41) are connected with pressure connection tube (30) by it.

5. by the device of claim 4, it is characterized in that: circular groove (40) is connected with pressure connection tube (30) by a passage (39) that is arranged in armature lever (17) guide device (18).

6. by the device of claim 5, it is characterized in that: the passage (39) of guide device (18) is connected with pressure connection tube (30) by opening the interior hole (38) that covers with packing ring (22) of electromagnet (10).

7. by the device of claim 6, it is characterized in that: the hole (38) of opening in the electromagnet (10) is connected with pressure connection tube (30) by a passage (37) that is distributed in the packing ring (22) that is installed in unlatching electromagnet (10) below.

8. by the device of claim 7, it is characterized in that: the passage (37) of packing ring (22) is connected with pressure connection tube by the circular groove (36) that is distributed in the annulus (23) that is installed in packing ring (22) below.

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