EP0970295B1 - Electromagnetic drive mechanism - Google Patents

Abstract

The invention relates to an electromagnetic drive mechanism with two opposite-lying electromagnets (2, 3) and an armature (10) which can move back and forth between said magnets. The armature (10) is held in an intermediate position by means of an elastic force and is brought into a final position by the force of said electromagnets (2, 3). The armature (10) is mounted by means of a torsion spring (6) and at least one drive mechanism including bearings forms a single structural unit.

Description

The invention relates to an electromagnetic drive the features of the preamble of claim 1.

A drive with the features of the preamble of claim 1 is, e.g. B. known from EP 0 043 426 B1. A problem with such drives, especially when used for Driving valves in internal combustion engines is heat dissipation from the solenoids. This problem is known to solve by complex water or oil rinsing. About that Furthermore, the known solutions show problems that have not been solved, such as B. closed assembly unit with electrical Connection and adjustment of the magnet systems to the residual air gap.

DE 36 16 540 A1 describes an electromagnetic drive known for a valve in which the drive to a Unit is summarized. The anchor is through one here Rolling bearings stored. In addition, outside of the Unit still a torsion spring with a transmission lever required on which the drive acts. It turns out here large masses to be moved, which means a high power requirement of the Drive.

DE-A-2 334 211 also discloses an electromagnetic one Servomotor of the type mentioned, in which the anchor is mounted by means of a torsion spring and wherein the entire servomotor forms one unit.

The invention is based on the object, the anchor as possible to store with little friction and an assembly-friendly arrangement create.

This object is solved by the features of claim 1.

The invention creates a pre-testable unit which when used for valve actuation for many engine types can be used as a standard, as a modular assembly module can.

According to a development of the invention, it is inexpensive to combine two drives into one unit. If here these two drives on a common one Base body can be mounted, the problem of heat dissipation solved well by embedding the coils in the base body become. One can create a fully testable assembly that is connected to the outside via a common plug of the invention, the torsion spring can be long because the entire width of the unit can be used. Besides, can the torsion spring with valve actuation and anchor with one Carrier plate are preassembled. It is a good adjustment of the magnet system possible while eliminating all tolerances, especially when a mechanical locking system is used, the anchor in the end positions without Electromagnetic excitation holds and the rest positions as Reference positions can be used. In addition, the magnets referenced to the magnet armature by means of screws or rivets adjusted and solidified with regard to the residual air gap become. The subclaims contain further refinements the invention.

At different operating temperatures e.g. B. Cold start, warm-up, steady state, restart have the components involved in heat transfer such as Cylinder block, valve and its actuation different Extensions with different time behavior. Have this then again influence on the anchor position, i.e. Residual air gap in closed state of the valve, in which the magnet system is effective. The different residual air gaps mean Effort in position control and higher electrical Power consumption with larger air gaps. By appropriate choice of materials, this change can be very small being held.

Exemplary embodiments of the invention are shown in the drawing explained.

Fig. 1

einen Grundkörper mit zwei darauf befestigten Antrieben in Seitenansicht samt einem angetriebenen Ventil,

Fig. 2 und 3

Ausführungsbeispiele ähnlich Figur 1

Fig. 4

ein weiteres Ausführungsbeispiel in anderer Ansicht,

Fig. 5

ein durch zwei Antriebe angetriebenes Ventil,

Fig. 6 und 7

Kastenausgestaltungen.

Show it:

Fig. 1

a base body with two drives attached to it in side view including a driven valve,

2 and 3

Exemplary embodiments similar to FIG. 1

Fig. 4

another embodiment in a different view,

Fig. 5

a valve driven by two drives,

6 and 7

Box designs.

A basic body is designated by 1 in FIG. It is in the 1 essentially only one drive detect. The second is behind. The visible drive has two electromagnets 2 and 3, whose yokes through Screws 4 are connected to the base body. The windings the electromagnets 2 and 3 are here for the sake of simplicity only shown schematically. The base body 1 is by means of Screws 5 attached to a box la, which in turn is attached to the cylinder block 20 by means of screws 5a.

Between the magnetic poles of the electromagnets 2 and 3 is a Anchor 10 is provided, which by a torsion spring z. B. one Torsion bar 6 is movably mounted. The torsion bar 6 and the corresponding torsion bar 7 for the armature of the other drive are shown in perspective for clarity. they are embedded in the body, clamped on one side in it (the torsion bar 6 at 8) and at the other end, e.g. B. means of a needle bearing. An anchor lever 9 is Connecting element between torsion bar 6 and anchor 10.

A locking system is provided at the top right, which consists of a an axis 11 tiltable rocker 12, a locking magnet 13, one Spring 14 and a ball-bearing locking roller 15, which in the end positions of the anchor above or below the anchor snaps and holds it in the end positions. On the The locking roller will be discussed again later. In the basic body can be an invisible junction box for a plug be provided.

The armature 10 is actuated via an actuating rod 16 and a Set screw 17 a valve 18 against the force of a spring 19. The length of the Actuating rod 16 can be changed. It serves the Setting the valve clearance at the dash-dotted line drawn position of the armature and then closed valve 18. Form the spring 19 and the bias of the torsion bar 6 the spring forces that without the excitation of an electromagnet Move the anchor to the intermediate position.

In Fig. 1 dimensions I1 for the valve length, I2 for the Valve block thickness, I3 for the distance of the axis of the torsion bar 6 from the valve block and I4 for the length of the actuating rod 16 registered.

The materials, i.e. H. the coefficient of thermal expansion of the Valve block 20, the valve 18, the actuating rod 16 and of the box la are now taking into account the lengths I1 to I4 chosen and coordinated so that at closed valve 18 despite different temperatures only a small valve clearance occurs.

2, which differs only slightly from FIG. 1, the same parts are designated by the same reference numerals. It the rest system is missing here; the adjusting screw 17 is by means of a valve spring 21 connected to the valve stem 18. This Spring is an overtravel spring, which different ways of Armature and the valve can compensate to a certain extent. In addition, here is the junction box 22 mentioned above recorded. The restoring force of the system is shown here done in both directions by the torsion spring.

In Fig. 3 is a height adjustment of the drive together Spring bearing opposite the box la or the cylinder block shown, it consists of a screw 30 and one Belleville spring 31.

The height adjustment option is used to adjust the valve clearance. When screws 5 are loosened, turning nut 30a the screw 30 of the base body 1 more or less strong pressed against the plate springs 31 and thus the distance 13 (Fig 1) varies.

Alternatively, it is also possible for valve clearance or Residual air gap setting only the upper magnet is adjustable. After correct valve lash setting related to one corresponding base air gap is the base body 1 by the Screws 5 screwed to the box.

Only the upper magnet can be adjusted above screw mechanism (30,30a) are used, as well as a construction where the magnet, accordingly the anchor construction, articulated on one side by means of a lever is rotatably mounted about an axis. By a The residual air gap and valve clearance are rotated around this axis adjustable because the relative distance between the poles the opposite magnetic yokes changed.

The magnet is adjusted against, for example Spring tension using an eccentric cam or over a screw mechanism. Advantageously Ensuring permanent adjustment of counter elements provided that secure the cam or screw elements.

In Fig. 4 is a unit with two drives for two Valves 58a and 58b in a 90 ° (compared to FIGS. 1 to 3) rotated view shown. The basic body is 41 designated by the screws 45 (corresponding to 5) on box not shown can be attached. The basic body 41 carries two support plates 42 and 43, one each Torsion bar 46 and 47 is attached. The carrier plates can be fastened to the base body 41 by rivets or screws. The torsion bar can be fastened in the carrier plate by a positive connection is effected, e.g. can one square connected with the torsion bar or a toothing in shrink the carrier plate. Also one can Welding e.g. Laser welding can be used. The Connection from the torsion bars to the anchor levers 49 can in done in the same way. For welding with the torsion bar a metal bushing can be shrunk in the armature lever. The support bearings 50 for the free ones can also be seen here Ends of the torsion bars 46 and 47, in particular as needle bearings are trained. The valves 58 are also here Coupling spring coupled. A threaded nut 59 and one Spindle 60 are used for valve adjustment.

For actuating a large valve (e.g. with 3-valve engines) can the actuating rods 60 two adjacent Actuators act on a valve stem 61 (Fig. 5).

6 shows a cylinder 7 of an internal combustion engine, whose piston 72 is currently in the upper position. An inlet valve 73 and an outlet valve 74 are shown which are guided in the cylinder head 75. Valves 73 and 74 are driven by electromagnetic drives, which in Boxes 76 and 77 are housed. These are not through screws shown screwed onto the cylinder head 75. The As shown above, drives have two electromagnets and one mounted on a torsion bar via a connecting part Anchor on. The torsion bar is dimensioned such that the Anchor without driving an electromagnet in one Intermediate position. On the connecting part is one Actuator rod 78 and 79 attached via a Overtravel spring 80 or 81 with valve stem 73 or 74 connected is. The overtravel springs 80 and 81 provide Normally a rigid coupling of the valve stem to the Actuating rod 78 or 79. Only if the anchor one executes a larger stroke than the valve can take part in, the Spring action.

The actuating rod including the overtravel spring protrude here from the bottom of the box. For better protection however, the parts are preferably not out of the box stick out. The connection between overtravel spring and Valve stem is detachable: e.g. have the overtravel springs 80 and 81 has a slot which, when installed in a groove of the Valve stem is inserted. For reasons of thermal expansion the actuating rod 78 or 79 is preferably made of Made of aluminum. With 82 a spark plug is designated. This could also be housed in one of the boxes.

A common cover 83 is for the two boxes 76 and 77 provided, in which the suction pipe 84 of the cylinder 71 is integrated is. On the lower wall 84a of the suction pipe 84 is the Electronics 85 of the drive unit, e.g. B. also for several Drives attached. It is 86 through thermal insulation thermally insulated from the actual drive. Heatsink 87 of the electronics protrude into the intake manifold and become so well cooled by the relatively cool intake air. Cover 83 and electronics 84 and heat sink 87 can by a common screw 88 may be attached. In the cover 83 one open - and lockable flap 79 to be integrated alternately a resonance suction tube - or To enable vibrating intake manifold operation.

7, which essentially corresponds to the left half of FIG. 6 matches, the torsion bar 90 is shown in box 91. At the Torsion bar is an anchor 93 via a connecting part 92 Electromagnet shown by two magnets, not shown can be moved up and down. Here are the screws 94 shown with which the box 91 is attached to the cylinder head is. At the connecting part 92 is not visible Actuating rod 95 (corresponds to 16 of FIG. 1) attached. On it is also attached to the carrier 96, part of a Stroke sensor 97 (z. B. Hall sensor).

Fig. 7 also shows a centering part 98 and in the cylinder block a housing centering 99. This ensures that the valve coupling is centered using the lift nut and snaps into the valve. There is also a locking device here 100 is provided, which is rotatable about the point 101. she serves as an assembly aid. Here too, the seal 102 is between Box and lid recognizable.

If there is talk of an accommodation in a box, so is also to be understood by this that the box only at the Assembly on the cylinder block from different parts arises.

By integrating the suction pipe into the lid of the box costs and weight are saved. By at least partial housing of the electronics of the drive unit or at least their heat sink in the relatively cool intake manifold on the one hand and the insulation of the electronics, the Electronics exposed to only a small amount of heat, what to a significantly reduced failure rate of the Electronic components leads. (Arrhenius law).

It is relatively easy to use a switching intake manifold Integrate control device.

The electrical connection (contacting) of the solenoids with the electronics is in this arrangement the electronics very easy to do because all contacts with the PCB can be connected. They can also Stroke sensors housed in the electronics (on the board) become. The possible placement of the spark plugs in the Box means a "dry" housing, which means the insulation effort and the required ignition energy decreased.

Claims (33)

1. Electromagnetic actuator (2, 3, 10) with two electromagnets (2;3), in particular the pole faces of which are turned at least partly towards each other and with an anchor (10) able to move backwards and forwards between these pole faces which is brought by spring forces (6, 7) into a mid position and held there when the magnets (2, 3) are switched off, and when one of the electromagnets (2, 3) is switched on is brought into an end position in the vicinity of the pole faces of the corresponding electromagnets (2, 3), whereby the anchor (10) is supported by means of a torsion spring (6), which at least partly produces the spring forces, and acts on a moving part (18) and at least one actuator (2, 3, 10) together with bearing (6) is assembled into a modular unit and this modular unit is attached to a component (20) which contains the moving part (18), characterised in that several modular units are held on a bracket or carrier element ( 1a ), in particular in a generally sealed case, and that this bracket or carrier element (la) is attached to the component (20).
2. Electromagnetic actuator in accordance with claim 1, characterised in that the modular unit comprises two actuators (2, 3, 10) which are mounted on a common basic body (1).
3. Electromagnetic actuator in accordance with claim 2, characterised in that the modular unit comprises both the actuators (2, 3, 10) together with bearing (6, 7).
4. Electromagnetic actuator in accordance with one of the above claims, characterised in that the electromagnets (2, 3) are attached by means of screws (4) or rivets to the basic body (1), and the residual air gap is changed by adjusting the magnet system before the electromagnets are fastened.
5. Electromagnetic actuator in accordance with one of the above claims, characterised in that the torsion springs (6, 7) are arranged at approximately the same height next to each other or underneath each other.
6. Electromagnetic actuator in accordance with one of the above claims, characterised in that the torsion springs (6, 7) are supported and mounted in the basic body (1).
7. Electromagnetic actuator in accordance with one of the above claims, characterised in that it has a pin and socket connection (21) and is designed as a verifiable unit (Fig. 2).
8. Electromagnetic actuator in accordance with one of the above claims, whereby the individual actuators each serve to drive a valve of a combustion engine, characterised in that a tappet clearance adjustment screw (17) is provided to adjust the tappet clearance.
9. Electromagnetic actuator in accordance with one of the above claims, whereby the individual actuators each serve to drive a valve of a combustion engine, characterised in that to adjust the tappet clearance each modular unit can be adjusted by means of a regulating device (30, 30a).
10. Electromagnetic actuator in accordance with claim 9, characterised in that the upper magnet (3) can be moved to adjust the tappet clearance or residual air gap.
11. Electromagnetic actuator in accordance with claim 10, characterised in that the magnet is mounted so that it can be moved, especially via a lever as connecting element, one way flexibly around an axis.
12. Electromagnetic actuator in accordance with claim 10, characterised in that the magnet is mounted so that it can be moved via a cam- or screw-mechanism around the axis.
13. Electromagnetic actuator in accordance with one of the above claims, characterised in that the electric windings (20) of the electromagnets rest in contact with the basic body (1).
14. Electromagnetic actuator in accordance with one of claims 1 to 7 and 13, characterised in that both actuators move a valve (Fig. 5).
15. Electromagnetic actuator in accordance with one of the above claims, characterised in that the torsion spring (46, 47) is clamped at one end in a carrier plate (42, 43) and on the free end is connected with an anchor lever (49) forming a connection to the anchor (10) and that the carrier plate (42, 43), the torsion spring (46, 47) and the anchor lever (49) form an assembly unit which is fixed in the modular unit in a non-positive or positive manner.
16. Electromagnetic actuator in accordance with one of the above claims, characterised in that the free end of the torsion spring (46, 47) has a support bearing (50).
17. Electromagnetic actuator in accordance with claim 16, characterised in that the support bearing is a needle bearing.
18. Electromagnetic actuator in accordance with one of claims 15 to 17, characterised in that the torsion spring (46, 47) is welded with the carrier plate (42, 43) and the anchor lever.
19. Electromagnetic actuator in accordance with one of claims 15 to 17, characterised in that the torsion springs are connected through a corresponding profile in a non-positive or positive manner with the carrier plate and the anchor lever.
20. Electromagnetic actuator in accordance with one of claims 8 to 19, characterised in that the design and material of the valve block, the valve (18) and the operating element (16) are selected in such way that in the end position of the valve (18), at different engine temperatures, the least possible influence is brought to bear on the anchor stroke or tappet clearance.
21. Electromagnetic actuator in accordance with one of claims 7 to 20, characterised in that the spring forces on the valve are produced through a torsion bar (6) and a pressure spring (19) (Fig.1)
22. Electromagnetic actuator in accordance with one of claims 7 to 21, characterised in that two actuators act on a valve.
23. Electromagnetic actuator in accordance with one of claims 8 to 22, characterised in that the bracket or carrier element, especially the case (la; 6, 7) with its base sits on the cylinder head (20; 75) and is connected with it.
24. Electromagnetic actuator in accordance with claim 23, characterised in that the case (6, 7) has a cover (73) and that the suction pipe (84) of a cylinder (71) of the combustion engine is integrated in this.
25. Electromagnetic actuator in accordance with claim 23 or 24, characterised in that the electronics (85) of the actuator are arranged at least partly in the suction pipe (84).
26. Electromagnetic actuator in accordance with claim 24 or 25, characterised in that cooling bodies (87) of the electronics (85) of the actuator unit protrude into the suction pipe (84).
27. Electromagnetic actuator in accordance with one of claims 23 to 26, characterised in that the electronics (85) are heat-insulated against the actuators. (Insulation 86)
28. Electromagnetic actuator in accordance with one of claims 23 to 27, characterised in that at least one spark plug is housed in the case.
29. Electromagnetic actuator in accordance with one of claims 23 to 28, characterised in that the operating elements (16, 78, 79) are made from aluminium.
30. Electromagnetic actuator in accordance with one of claims 23 to 29, characterised in that the valve has a stop (100) to aid assembly.
31. Electromagnetic actuator in accordance with one of claims 23 to 30 characterised in that the case (76, 77) has a centring part (98) and a centring (99) is provided for the case (76, 77) in the cylinder block.
32. Electromagnetic actuator in accordance with one of claims 23 to 31, characterised in that a control suction pipe (89) with control unit is integrated in the cover unit (83).
33. Electromagnetic actuator in accordance with one of the above claims, characterised in that the cover unit (83) is connected by screws (88) with the sealed case.

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