JPH0466705A - Electromagnetic force valve drive device - Google Patents

Abstract

PURPOSE:To reduce the inertia mass of a reciprocation drive system without lowering suction force, by opposing fixed magnetic poles to the whole periphery of a movable magnetic pole, and making the force of suction acting on the movable magnetic pole, equal and strong, and at the same time making the outer periphery portion thickness of the movable magnetic pole thinner than that of the center portion. CONSTITUTION:When a controller 4 outputs a control signal to an initial drive device 41, electric power is supplied to a magnetizing coil 33, and fixed magnetic poles 31, 32 are magnetized. As a result, a movable magnetic pole 11 is sucked by poles 31, 32, and an air suction valve 1 is driven in an opening direction. In this instance, the plate thickness of the pole 11 is formed so that reduction may be made toward the periphery portion direction from the center portion, and the area of a magnetic passage formed between this pole 11 and poles 31, 32 is set uniformly from the center portion to the outer periphery portion. And confrontation with a drive portion 3 is made through a center magnetic pole 34 outer periphery surface and a rotor 2. That is, a plurality of a stator magnetic poles 35 opposing the outer periphery surface of the rotor 2 are provided. Also, poles 35 are opposed to the whole periphery of the outer periphery surface of the rotor 2, and also provided in plural steps in the reciprocation direction of the movable 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electromagnetic force valve drive device that opens and closes intake and exhaust valves of an engine using electromagnetic force.

(Prior art) A conventional intake/exhaust valve opening/closing drive device operates from the cam surface of a camshaft, which is driven by the output shaft of the engine and rotates in synchronization with the engine rotational phase, through a link mechanism such as a rocker arm or bushing rod. By pushing the shaft end face of the valve, the intake and exhaust valves, which are normally biased in the closing direction by a spring, are opened and closed.

As described above, the opening/closing drive device requires a camshaft and a link mechanism to be attached to the engine, resulting in an enlarged engine. Additionally, a portion of the engine output is consumed due to frictional resistance when driving the camshaft and link mechanism, reducing the effective output of the engine.

Furthermore, since the opening/closing timing of the intake and exhaust valves cannot be easily changed while the engine is running, the valve opening/closing timing must be adjusted to achieve the optimum operating condition when the engine is running at a predetermined engine speed. Therefore, when the engine is operated at a rotational speed different from the predetermined rotational speed, there is a problem that the output and efficiency that the engine is originally capable of cannot be extracted.

Therefore, in order to solve the above problem, instead of opening and closing the intake and exhaust valves by a camshaft, the movable magnetic pole connected to the intake and exhaust valves is attracted by the electromagnetic force of an electromagnet fixed to the engine, and the intake and exhaust valves are A number of valve drive devices have been proposed that drive the valve to open and close while changing the timing of opening and closing, such as those described in JP-A-58-183805 and JP-A-61-76713.

(Problem to be Solved by the Invention) In the valve drive device that opens and closes the intake and exhaust valves using the electromagnetic force of the above-mentioned back and forth, the movable magnetic pole is formed of a magnetic material in order to increase the density of the magnetic flux flowing inside the movable magnetic pole. has been done.

However, since magnetic materials have a large specific weight, the inertial mass of the reciprocating drive system of the intake and exhaust valves increases, and the acceleration during reciprocating drive of the intake and exhaust valves is limited, making it difficult to operate the engine at high speeds. The problem is that I can't.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an electromagnetic force valve drive device that reduces the inertial mass of the reciprocating drive system of intake and exhaust valves and enables the engine to operate in a high-speed rotation region. It is something to do.

(Means for Solving the Problems) According to the present invention, in an electromagnetic force valve driving device that drives a reciprocating movable magnetic pole connected to an intake/exhaust valve with a fixed magnetic pole to open/close the intake/exhaust valve, the above-described A disc-shaped movable magnetic pole that abuts the intake and exhaust valve at the center and whose plate thickness gradually decreases from the center to the outer circumference, and faces each of the center and outer circumference of one surface of the movable magnetic pole. It is possible to provide an electromagnetic force valve driving device characterized by having a fixed electromagnet having double annular magnetic poles and a regulating means connected to the intake and exhaust valves and controlling the moving speed of the intake and exhaust valves.

(Function) In the electromagnetic force valve driving device of the present invention, since the fixed magnetic pole faces the entire inner and outer periphery of one surface of the movable magnetic pole,
The attractive force acting on the movable magnetic pole becomes uniform and strong.

Furthermore, since the thickness of the outer circumferential portion of the movable magnetic pole is made thinner than the thickness of the central portion, the inertial mass of the reciprocating drive system is reduced without reducing the attractive force.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the drive device of the present invention;
FIG. 2 is a view taken along the ■-■ arrows. Incidentally, although the engine is provided with an intake valve and an exhaust valve as described above, the drive device according to the present invention can be applied to both the intake and exhaust valves, and therefore, the device for opening and closing the intake valve will be mainly described below.

Reference numeral 1 denotes an intake valve made of a ceramic material such as silicon nitride, which is lightweight and has excellent high-temperature strength. A disk-shaped movable magnetic pole 11 is brought into contact with the shaft end of the intake valve 1 .

The thickness of the movable magnetic pole 11 is formed to decrease from the center toward the periphery, so that the area of the magnetic path formed between it and the fixed magnetic pole described later is uniform from the center to the outer periphery. has been done.

The intake valve 1 is reciprocably supported by a valve guide 12, and when the intake valve 1 is closed, the umbrella portion of the intake valve 1 rests on the valve seat 14 to close the intake port.

A movable element 2, which will be described later, is located near the center of the shaft of the intake valve 1.
are connected. Furthermore, in order to prevent the intake valve 1 from falling when the engine is stopped, the movable element 2 is biased in the closing direction by a spring 13.

3 is a driving section. An annular fixed magnetic pole 31 facing the central portion of the lower surface of the movable magnetic pole 11 and an annular fixed magnetic pole 32 facing the outer circumference of the movable magnetic pole 11 are provided at the upper end of the drive unit 3 in the drawing. . The fixed magnetic pole 31 and the fixed magnetic pole 32 are arranged concentrically, and an excitation coil 33 for exciting the fixed magnetic pole 31 and the fixed magnetic pole 32 is arranged between the fixed magnetic pole 31 and the fixed magnetic pole 32. ing.

The fixed magnetic pole 31 is disposed around the outer peripheral surface of the shaft portion of the intake valve 1 with a small space therebetween, and a central magnetic pole 34 is provided extending below the fixed magnetic pole 31.

The central magnetic pole 34 is formed in a cylindrical shape and is provided at a position surrounding the shaft portion of the intake valve 1. Further, the outer circumferential surface of the central magnetic pole 34 faces the inner circumferential surface of the movable element 2.

The drive unit 3 is further provided with a plurality of stator magnetic poles 35 that face the outer circumferential surface of the central magnetic pole 34 via the movable element 2, that is, face the outer circumferential surface of the movable element 2. The stator magnetic poles 35 face the entire outer peripheral surface of the movable element 2,
A plurality of stages are provided in the reciprocating direction of the movable element 2. A primary coil 36 is wound around the stator magnetic pole 35, and the chromaticity and direction of the magnetic flux passing through the stator magnetic pole 35 can be controlled for each stage.

4 is a controller, which includes an input/output interface that controls the input and output of signals, a ROM that stores programs and various relationship maps in advance, a CPU that executes calculations according to the programs stored in the ROM, and a temporary storage that stores calculation results and data. The control memory includes a RAM for controlling the controller 5, a control memory for controlling the flow of signals inside the controller 5, and the like.

An initial drive device 41 and a speed adjustment device 42 are connected to the controller 4 . The initial drive device 41 is connected to the excitation coil 33, and when a control signal from the controller 4 is input, it supplies power to the excitation coil 33 to excite the fixed magnetic poles 31 and 32. .

Further, the speed adjusting device 42 is connected to each stage of the primary coil 36, and when a speed control signal from the controller 4 is input, the speed adjusting device 42 is connected to an alternating current with a different phase for each stage of the primary coil 36. Supplying power to the stator magnetic poles 35
A traveling magnetic field is formed by the magnetic flux passing through the magnetic flux, and the traveling speed and direction of the traveling magnetic field are controlled.

Next, the mover 2 will be explained.

FIG. 3 is a cross-sectional perspective view of the movable element.

The mover 2 is formed in a cup shape, that is, a cylindrical shape with a bottom, and is held by a core 21 made of a composite material of magnetic powder and plastic.
It is composed of a plurality of closed annular secondary coils 22 connected to the intake valve 22.

The magnetic powder contained in the core 21 is made of, for example, short fibers of silicon steel or fine particles of silicon steel. Next, the movable element 2 is formed by filling the mixed material into a mold in which the coil 22 is placed at a predetermined position by the support member 23.

Alternatively, it may be formed by mixing thermoplastic plastic powder and magnetic powder, filling the mixture into a mold, and then heating to melt the plastic.

Since the secondary coil 22 is required to be lightweight, it is made of a metal material, such as aluminum, that is conductive and has a small specific weight, or a conductive ceramic.

Therefore, the mover 2 created in this manner is lightweight and has excellent magnetic permeability, and the inertial mass of the reciprocating drive system of the intake valve 1 can be significantly reduced.

Next, the operation of the apparatus of the present invention having the above configuration will be explained.

During engine operation, the controller 4 constantly detects the engine load and the rotational phase of the engine. and,
The opening/closing timing and lift amount of the intake valve corresponding to the engine load are calculated.

Then, when the actual engine rotation phase reaches the calculated intake valve opening timing, the controller 4 outputs a control signal to the initial drive device 41. Then, as described above, power is supplied to the excitation coil 33 and the fixed magnetic pole 31 and the fixed magnetic pole 32 are excited. FIG. 4 shows a state in which the fixed magnetic pole 31 is excited to the S pole and the fixed magnetic pole 32 is excited to the N pole.

FIG. 4 is a diagram showing the state of magnetic flux acting on the movable magnetic pole.

In this figure, the arrow indicated by B indicates the flow of magnetic flux. As shown in this figure, the magnetic flux emitted from the fixed magnetic pole 32 passes through the interior of the movable magnetic pole 11 and forms a magnetic path flowing to the fixed magnetic pole 31. Therefore, the movable magnetic pole 11 is attracted to the fixed magnetic pole 31 and the fixed magnetic pole 32, and drives the intake valve 1 in the opening direction.

Note that if the thickness of the movable magnetic pole 11 is constant, the movable magnetic pole 1
1. The internal magnetic flux density is sparser at the outer periphery than at the center, so even if you reduce the plate pressure at the outer periphery and keep the magnetic flux density between the center and outer periphery constant as shown in this figure, the attractive force will be There will be no decrease.

By reducing the plate pressure in this manner, the inertial mass of the reciprocating drive system of the intake valve 1 is reduced, so that a greater acceleration can be achieved.

In this way, when power is supplied to the excitation coil 33 and the intake valve 1 is initially driven, the intake valve 1 is driven to the lift amount calculated above, and then the intake valve 1 is moved to the valve seat at the calculated closing timing. Adjust the moving speed of the intake valve l so that it is seated at the position 14. The adjustment of the moving speed is performed by outputting a speed control signal from the controller 4 to the speed adjustment device 42, as described above.

The bias of the spring 14 that holds the intake valve 1 in a closed state is set to be sufficiently small with respect to the electromagnetic force described above.

Although the embodiments have been described in detail above, various different embodiments can be easily constructed without departing from the spirit of the present invention. It is not limited to examples.

(Effects of the Invention) As explained above, according to the present invention, the fixed magnetic pole faces the movable magnetic pole along the entire inner and outer circumferential portions of one surface of the movable magnetic pole, so that the attractive force acting on the movable magnetic pole is reduced. Can be made even and powerful.

In addition, since the thickness of the outer periphery of the movable magnetic pole is made thinner than the thickness of the central part, the attraction force is not reduced (the inertial mass of the reciprocating drive system can be reduced, and therefore the engine can be operated in the high-speed rotation range). It is possible to provide an electromagnetic force valve drive device that enables this.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the drive device of the present invention;
FIG. 2 is a sectional view taken along the line ■-■, FIG. 3 is a cross-sectional perspective view of the movable element, and FIG. 4 is a diagram showing the state of magnetic flux acting on the movable magnetic pole. DESCRIPTION OF SYMBOLS 1... Intake valve, 2... Movable element, 3... Drive part, 4... Controller, 11... Movable magnetic pole, 21...
... Core, 22 ... Secondary coil, 36 ... Primary coil. Figure 2 Figure 3

Claims (3)

[Claims] (1) In an electromagnetic force valve drive device that uses a fixed magnetic pole to attract a reciprocating movable magnetic pole connected to an intake/exhaust valve to open/close the intake/exhaust valve, a plate is brought into contact with the intake/exhaust valve at its center. a fixed electromagnet having a disk-shaped movable magnetic pole whose thickness gradually decreases from the center toward the outer circumference; and a fixed electromagnet having double annular magnetic poles facing each of the center and outer circumference of one surface of the movable magnetic pole; An electromagnetic force valve driving device characterized by comprising speed regulating means connected to an exhaust valve and controlling the moving speed of the intake and exhaust valve. (2) The speed governor consists of a gap provided in the middle of the magnetic flux path generated from the primary coil fixed to the engine, a reciprocating secondary coil connected to the intake and exhaust valves, and a magnetic material. 2. The electromagnetic force valve driving device according to claim 1, further comprising a movable element that moves reciprocally in the gap, forms a part of the magnetic flux path, and includes the secondary coil. (3) Claim (1) characterized in that the intake and exhaust valves are made of ceramic, which is a lightweight and high-strength material.
) electromagnetic force valve drive device.