JPH03182604A - Induction-type electromagnetic force valve drive unit - Google Patents

Abstract

PURPOSE:To perform stable change-over control on an intake/exhaust valve without being influenced by the movement of the intake/exhaust valve by providing fixed magnetic poles in a row on the side faces of secondary coils provided on the periphery of a movable magnetic pole. CONSTITUTION:The magnetic passage 21 of a movable piece 2 is connected to an intake valve 1 and reciprocated. The magnetic poles 33-36 of a drive part 3 are lined up in the direction of reciprocating motion and constantly opposed to the peripheral surface of the magnetic passage 21. Exciting coils 331-361 are wound on the magnetic poles 33-36, and secondary coils 22-26 are provided around the peripheral surface of the magnetic passage 21. When electric power is supplied to the exciting coils 331-361 and an upper coil 32 from a controller 4, a progressive magnetic field is formed by the magnetic poles 33-36 lined up at the side faces of the secondary coils 22-26, and a current induced by the secondary coils 22-26 reciprocates the intake valve 1 by the electromagnetic force received from the progressive magnetic field. Accordingly, driving force remains the same even if the position of the intake valve is changed, so that stable change over control can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an induction type electromagnetic force valve driving 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 pushes the end face of the valve shaft from the cam surface of a camshaft that rotates in synchronization with the engine rotational phase via a link mechanism such as a rocker arm or bushing rod. This opens and closes the intake and exhaust valves, which are always biased in the closing direction by springs. The opening/closing drive device requires a camshaft and a link mechanism to be attached to the engine, which increases the size of the engine and consumes a portion of the engine output due to frictional resistance when driving the camshaft and link mechanism. Effective output decreases. Furthermore, since the opening and closing timing of the intake and exhaust valves cannot be changed while the engine is running, the valve opening and closing timing must be adjusted according to the predetermined engine speed. There is a problem that the output and efficiency of the system are reduced.

Therefore, in order to solve the above problem, a device for opening and closing the intake and exhaust valves using electromagnetic force generated by an electromagnet instead of using a camshaft was proposed in Japanese Patent Laid-Open No. 58-183805 or No. 61-76713. Are listed.

(Problem to be Solved by the Invention) However, the device disclosed in the above two publications attracts a magnetic body attached to an intake/exhaust valve with an electromagnet disposed in the direction of movement of the intake/exhaust valve. This is to drive the intake and exhaust valves.

Since the attractive force acting on the magnetic body is inversely proportional to the square of the distance between the electromagnet and the magnetic body, there is a problem in that the attractive force changes as the distance changes, making the driving of the intake and exhaust valves unstable. Furthermore, at the start of driving, it is necessary to apply a strong acceleration force to the intake and exhaust valves, but in the devices disclosed in the above two publications, the distance between the electromagnet and the magnetic body is maximum at the start of driving, and therefore the intake and exhaust valves Only a minimum driving force can be applied to the

The present invention has been made in view of the above points, and is capable of stably controlling the opening and closing of the intake and exhaust valves without being affected by the movement of the intake and exhaust valves, and in which the driving force acting on the intake and exhaust valves is not affected by the movement of the intake and exhaust valves. The present invention attempts to provide an electromagnetic force valve driving device that sometimes applies a strong driving force to intake and exhaust valves.

(Means for Solving the Problems) According to the present invention, there is provided a movable magnetic pole that is connected to an intake and exhaust valve of an engine and can freely reciprocate, and a fixed magnetic pole that is arranged in parallel in the direction of the reciprocating motion and always faces the outer peripheral surface of the movable magnetic pole. and an excitation coil that is wound around the fixed magnetic pole and forms a fixed magnetic field in which the direction of the magnetic field from each fixed magnetic pole is the same when the intake and exhaust valves are initially driven, and forms a traveling magnetic field in the reciprocating direction when in the open state; A fixed coil having a secondary coil disposed around the outer peripheral surface of the movable magnetic pole so as to face the fixed magnetic pole, and a magnetic pole facing the end face of the movable magnetic pole, and which induces a current in the secondary coil when the intake and exhaust valves are initially driven. It is possible to provide an induction type electromagnetic force valve driving device characterized by having an electromagnet and a power supply means for supplying power to the excitation coil and the fixed electromagnet to open and close the intake and exhaust valves.

(Function) In the induction type electromagnetic force valve driving device of the present invention, a traveling magnetic field is formed by the fixed magnetic pole arranged in parallel on the side surface of the secondary coil surrounding the movable magnetic pole, and the current induced in the secondary coil is Since the intake and exhaust valves are reciprocated by the electromagnetic force received from the traveling magnetic field, the driving force does not change even if the position of the intake and exhaust valves changes, and therefore stable opening/closing control can be performed.

In addition, during initial drive, a magnetic field in the same direction is applied to the secondary coil from the outer periphery, and the current induced by the fixed electromagnet facing the end face of the movable magnetic pole is driven by the electromagnetic force received from the magnetic field in the same direction. Therefore, the driving force acts on all the secondary coils, and it is therefore possible to generate a strong driving force.

Furthermore, since the fixed magnetic pole that forms the traveling magnetic field is always facing the movable magnetic pole, the magnetic resistance is small, and the amount of heat generated by the excitation coil wound around the fixed magnetic pole is suppressed, so there is no possibility of disconnection of the excitation coil. can be prevented.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a drive device of the present invention. 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, so the following explanation will mainly be made regarding the intake valve.

1 is an intake valve made of a ceramic material such as silicon nitride, which is lightweight and has excellent high-temperature strength, or a heat-resistant alloy.

The shaft portion of the intake valve 1 is rotatably supported by a valve guide 12. When the intake valve 1 is closed, the umbrella portion of the intake/exhaust valve 1 is seated on the valve seat 13 to close the intake port, as shown in this figure.

A movable element 2 is connected to the shaft end of the intake valve l.

The mover 2 includes a cylindrical magnetic path 21 and a magnetic path 2.
A plurality of secondary coils 22 to 26 provided around the outer peripheral surface of 1
It consists of The secondary coils 22 to 26 are formed by pouring molten aluminum into grooves cut on the outer peripheral surface of the magnetic path 21. The magnetic path 21 is made of a magnetic material in order to increase the magnetic flux density, and is formed by, for example, amorphous thin plates of magnetic metal arranged radially into a cylindrical shape. The movable element 2 is connected to the shaft end of the intake valve 1 via a stopper stopper 23 made of hard plastic.

A driving section 3 is arranged around the movable element 2. The drive unit 3 includes a central magnetic pole 3 facing the upper end surface of the magnetic path 21.
1, a plurality of magnetic poles 33 to 36 facing the secondary coils 22 to 26, excitation coils 331 to 361 wound around each of the magnetic poles 33 to 36, and an upper part wound around the central magnetic pole 31. It is composed of a coil 32 and the like. Note that even when the intake valve 1 moves in the reciprocating direction, the magnetic poles 33 to 36 are always provided at positions facing the side surfaces of the magnetic passage 21.

The excitation coils 331 to 361 and the upper coil 32 are connected to the controller 4 and receive power from the controller 4.

The controller 4 receives detection signals from a rotation sensor 5 that detects the engine speed and crank angle, and a load sensor 6 that detects the amount of depression of an accelerator pedal (not shown).

The controller 4 includes an input/output interface that controls the input of the detection signal and the supply of power, 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 It consists of a RAM that temporarily stores data, a control memory that controls the flow of signals inside the controller 4, and the like.

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

While the engine is running, the load sensor 6 constantly detects the amount of accelerator pedal depression and the rotational speed of the engine from the rotation sensor 5, and a preset relationship map is used to detect the intake air that corresponds to the amount of depression and the number of rotations. Calculate the opening/closing timing of valve 1. Then, when the crank angle detected by the rotation sensor 5 reaches the opening timing of the intake valve 1,
By energizing the upper coil 32, the secondary coils 22~
26 to generate an induced current, and the induced current and exciting coil 3
The intake valve 1 is initially driven by the magnetic field formed by 31 to 361. After the drive is started, alternating power is supplied to the excitation coils 331 to 361, and the magnetic field formed by the magnetic flux from the magnetic poles 33 to 36 is used as a traveling magnetic field to drive the intake valve 1 to open and close.

FIG. 2 is a diagram showing the state at the time of initial driving.

When the intake valve 1 is in the closed state, the upper coil 32 is energized to apply a magnetic flux from the central magnetic pole 31 in the direction of the movable element 2, that is, in the downward direction, as shown in FIG. 3(a).

When the crank angle reaches the opening timing of the intake valve 1, power supply to the upper coil 32 is stopped.

Then, a current is induced in the secondary coils 22 to 26 in a direction that continues the downward magnetic flux, that is, in a direction shown in FIG.

When the power supply to the upper coil 32 is stopped, the excitation coil 3
31 to 361, the magnetic pole 3 is connected as shown in this figure (b).
Inward magnetic flux is applied to each of the secondary coils 22 to 26 from 3 to 36. Then, the secondary coil 22-2
The induced current induced in the magnetic poles 33 to 36
Due to the magnetic flux from , it receives an electromagnetic force shown by Fleming's left-hand rule, that is, a downward electromagnetic force in the case of this figure. The electromagnetic force acts on almost the entire circumference of the secondary coils 22 to 26 and acts on all of the plurality of secondary coils 22 to 26, so the resultant force of the electromagnetic force acts on the intake valve 1 as a strong driving force. , drives the intake valve 1 in the opening direction.

The driving force during the initial drive only acts for a short time while the induced current is generated in the secondary coils 22 to 26 after the supply of molding to the upper coil 32 is stopped.
361 is switched to alternating power in the downward direction, that is, in the opening direction of the intake valve 1, and a downward traveling magnetic field is applied to the secondary coils 22 to 26.

When the magnetic flux acting on each of the secondary coils 22 to 26 changes as the magnetic field advances, the amount of magnetic flux interlinking with the secondary coils 22 to 26, that is, the magnetic flux density increases or decreases.
An induced current is generated in each of the secondary coils 22 to 26 in a direction that maintains the magnetic flux state. The induced current receives an electromagnetic force from the magnetic field in the same direction as the traveling direction of the magnetic field. Therefore, the intake valve 1 is driven downward.

To reduce the moving speed of the intake valve 1 in the opening direction, the moving speed of the traveling magnetic field is slowed down, stopped, or reversed. Then, a braking force acts on the secondary coils 22 to 26, and the intake valve 1 is stopped by the braking force and the reaction force of the two springs.

In order to drive the intake valve 1 from the stopped state to the closing direction, the traveling direction of the traveling magnetic field may be set upward, that is, in the closing direction. However, since the slippage with respect to the traveling magnetic field is large at the moment of starting from the stopped state. Although the driving force acting on the intake valve 1 is small, the reaction force of the spring 29
In order to assist the drive in the closing direction, the movable element 2 immediately starts moving in the closing direction.

When the intake valve 1 moves to a predetermined position, the traveling speed of the advancing magnetic field is slowed down, stopped, or reversed, and the moving speed of the intake valve 1 in the closing direction is slowed down so that the intake valve 1 is gently seated.

During the opening/closing movement of the intake valve 1, the magnetic poles 33 to 36 always face the magnetic passage 21 made of a magnetic material. Therefore, since the magnetic resistance is always small, that is, the self-inductance of the excitation coils 331 to 361 is small, the excitation coils 331 to
The impedance of 361 becomes small and the exciting coil 331
The amount of heat generated at ~361 can be reduced.

The bias of the spring 24 that holds the intake valve 1 in the closed state is set to be sufficiently small with respect to the electromagnetic force in the opening direction.

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, in the induction type electromagnetic force valve driving device of the present invention, the movement is caused by the fixed magnetic pole arranged in parallel on the side of the secondary coil disposed around the movable magnetic pole. A magnetic field is formed, and the current induced in the secondary coil drives the intake and exhaust valves back and forth due to the electromagnetic force received from the traveling magnetic field, so even if the position of the intake and exhaust valves changes, the driving force does not change. ,
Stable opening/closing control can be performed, and during initial drive, a magnetic field in the same direction is applied to the secondary coil from the outer periphery, and the current induced by the fixed electromagnet facing the end face of the movable magnetic pole is in the same direction. Since it is driven by the electromagnetic force received from the magnetic field in the direction, the driving force acts on all the secondary coils,
Therefore, a strong driving force can be generated, and since the fixed magnetic pole that forms the traveling magnetic field always faces the movable magnetic pole, the magnetic resistance is small, and the fixed lii! Since the amount of heat generated by the excitation coil wound around the pole is suppressed, it is possible to provide an induction type electromagnetic force valve driving device that can prevent the excitation coil from being disconnected.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a state at the time of initial driving. DESCRIPTION OF SYMBOLS 1... Intake valve, 2... Mover, 3... Drive unit, 4... Controller, 5... Rotation sensor, 6...
・Load sensor, 22-26...Secondary coil, 31...
・Central magnetic pole, 32... Upper coil, 33-36...
Magnetic poles, 331-361...excitation coils.

Claims (2)

[Claims] (1) A movable magnetic pole that is connected to the intake and exhaust valves of the engine and can freely reciprocate, a fixed magnetic pole that is arranged in parallel in the direction of the reciprocating motion and always faces the outer peripheral surface of the movable magnetic pole, and an intake and exhaust valve that is wound around the fixed magnetic pole. an excitation coil that forms a fixed magnetic field with the same magnetic field direction from each fixed magnetic pole during initial drive, and forms a traveling magnetic field in the reciprocating direction when in the open state; a secondary coil disposed around the movable magnetic pole, a fixed electromagnet having a magnetic pole facing the end face of the movable magnetic pole and inducing current in the secondary coil during initial operation of the intake and exhaust valves, and supplying electric power to the excitation coil and the fixed electromagnet. 1. An induction type electromagnetic force valve driving device comprising: power supply means for supplying electric power to open and close intake and exhaust valves. (2) The induction type electromagnetic force valve driving device according to claim (1), wherein a plurality of the secondary coils are arranged in parallel in the reciprocating direction.