JP2759358B2 - Induction type electromagnetic valve drive - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an induction-type electromagnetic valve driving device that drives an intake and exhaust valve of an engine to open and close by an electromagnetic force.

(Prior art) A conventional drive device for opening and closing an intake / exhaust valve pushes a shaft end face of a valve from a cam surface of a cam shaft rotating in synchronization with an engine rotation phase via a link mechanism such as a rocker arm or a pushing rod. Thus, the intake and exhaust valves constantly biased in the closing direction by the spring are driven to open and close. In the opening / closing drive device, a camshaft and a link mechanism must be attached to the engine. Therefore, the size of the engine increases, and a part of the engine output is consumed due to frictional resistance when driving the camshaft and the link mechanism. The effective output decreases. Further, since the opening and closing timing of the intake and exhaust valves cannot be changed during the operation of the engine, the valve opening and closing timing must be adjusted in accordance with a predetermined engine speed. Therefore, there is a problem that the engine output and efficiency are reduced when the engine is operated at a rotation speed different from the predetermined rotation speed.

Therefore, in order to solve the above problem, a device that performs opening and closing driving of the intake and exhaust valves by an electromagnetic force by an electromagnet without using a camshaft is disclosed in Japanese Patent Application Laid-Open No. 58-183805 or Japanese Patent Application Laid-Open No. 61-76713. Have been described.

(Problems to be Solved by the Invention) However, the device disclosed in the above two publications attracts a magnetic body attached to the intake / exhaust valve by an electromagnet arranged in the moving direction of the intake / exhaust valve, and generates the attraction force. This drives the intake and exhaust valves.

Since the attractive force acting on the magnetic material is inversely proportional to the square of the distance between the electromagnet and the magnetic material, there is a problem that the attractive force changes with the change in the distance, and the driving of the intake and exhaust valves becomes unstable. At the start of driving, a strong acceleration force must be applied to the intake and exhaust valves. However, in the device disclosed in the above-mentioned publication, the distance between the electromagnet and the magnetic body at the start of driving is maximized. Can be applied only to the minimum driving force.

The present invention has been made in view of the above points, and performs a stable opening and closing control of the intake and exhaust valves without affecting the driving force acting on the intake and exhaust valves by the movement of the intake and exhaust valves,
It is another object of the present invention to provide an electromagnetic valve driving device that applies a strong driving force to the intake and exhaust valves at the start of driving.

(Means for Solving the Problems) According to the present invention, a movable element which is connected to at least one of the intake and exhaust valves of an engine and is reciprocally movable, and a movable element which is arranged in the reciprocating direction and is arranged in parallel with the movable element. A magnetic pole constantly facing the outer peripheral surface, an exciting coil wound around the magnetic pole and forming a traveling magnetic field in the reciprocating motion direction in the open state, and a perpendicular surface in the moving direction facing the magnetic pole on the outer peripheral surface of the mover. A secondary coil circumferentially provided so as to be parallel, a central magnetic pole facing the upper end face of the mover, and an upper coil wound therearound; and a current is induced in the secondary coil when the valve is initially driven. An induction type electromagnetic force valve driving device comprising: a fixed electromagnetic force to be applied; and power supply means for supplying power to the excitation coil and the fixed electromagnet to open and close the valve.

(Operation) In the induction-type electromagnetic valve driving device according to the present invention, a traveling magnetic field is formed by magnetic poles juxtaposed on the side surface of the secondary coil provided around the mover, and the current induced in the secondary coil advances. Since the intake / exhaust valve is reciprocally driven by the electromagnetic force received from the magnetic field, the driving force does not change even if the position of the intake / exhaust valve changes, so that stable opening / closing control can be performed.

In addition, at the time of initial drive, a magnetic field in the same direction is applied to the secondary coil from the outer circumference, and the secondary coil is driven by an electromagnetic current received from the magnetic field in the same direction induced by the fixed electromagnet facing the end face of the mover. The driving force acts on all the secondary coils, and thus a strong driving force can be generated.

Furthermore, since the magnetic pole forming the traveling magnetic field is opposed to the mover, the magnetic resistance is reduced, and the amount of heat generated by the exciting coil wound around the magnetic pole is suppressed, so that disconnection of the exciting coil is prevented. be able to.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a driving device according to the present invention. Although the engine is provided with the intake valve and the exhaust valve as described above, the drive device according to the present invention can be applied to both the intake and exhaust valves.

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, or a heat-resistant alloy. The shaft of the intake valve 1 is reciprocally supported by a valve guide 12. When the intake valve 1 is closed, an umbrella portion of the intake / exhaust valve 1 sits on the valve seat 13 to open and close the intake port as shown in FIG.

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

A drive unit 3 is provided around the mover 2. The drive unit 3 includes a central magnetic pole 31 facing the upper end surface of the magnetic path 21.
And a plurality of magnetic poles 33- facing the secondary coils 22-26.
36, and an exciting coil 331 wound around each of the magnetic poles 33 to 36.
To 361, and the upper coil 32 wound around the central magnetic pole 31 and the like. Note that a fixed electromagnet is constituted by the central magnetic pole 31 and the above-mentioned upper coil for generating magnetic flux. Further, even when the intake valve 1 moves in the reciprocating direction, the magnetic poles 33 to 36 are provided at positions always 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.

Detection signals are input to the controller 4 from a rotation sensor 5 for detecting the number of revolutions and the crank angle of the engine, and a load sensor 6 for detecting the amount of depression of an accelerator pedal (not shown).

The controller 4 includes an input / output interface for inputting the detection signal and supplying power, a ROM for storing programs and various relationship maps in advance, a CPU for performing calculations in accordance with the programs stored in the ROM, It comprises a RAM for temporarily storing data, a controller memory for controlling the flow of signals inside the controller 4, and the like.

Next, the operation of the device of the present invention having the above-described configuration will be described.

During the operation of the engine, the depression amount of the accelerator pedal is constantly detected from the load sensor 6 and the rotation speed of the engine from the rotation sensor 5, and the intake air corresponding to the depression amount and the rotation speed is determined using a preset relationship map. The opening / closing timing of the valve 1 is calculated. Then, when the crank angle detected by the rotation sensor 5 reaches the opening timing of the intake valve 1, the upper coil 32 is energized so that the secondary coils 22 to
26, a dielectric current is generated, and the induced current and the exciting coil 331 are generated.
To 361, the intake valve 1 is initially driven. After the start of driving, the excitation coils 331 to 3
Alternating electric power is supplied to 61, and a magnetic field formed by magnetic fluxes from the magnetic poles 33 to 36 is used as a traveling magnetic field, so that the intake valve 1
To open and close.

 FIG. 2 is a diagram showing a 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 toward the mover 2, that is, downward, as shown in FIG.

When the crank angle reaches the opening timing of the intake valve 1,
The power supply to the upper coil 32 is stopped. Then, a current is induced in the secondary coils 22 to 26 in the direction in which the magnetic flux continues in the downward direction, that is, in the direction shown in FIG.

When the power supply to the upper coil 32 is stopped, the excitation coil 33
1 to 361 are energized to cause inward magnetic flux to act on each of the secondary coils 22 to 26 from the magnetic poles 33 to 36 as shown in FIG. Then, the induced current induced in the secondary coils 22 to 26 is an electromagnetic force indicated by Fleming's left-hand rule due to the magnetic flux from the magnetic poles 33 to 36, that is, in the case of FIG. Receive strength. The electromagnetic force acts on almost the entire circumference of the secondary coils 22 to 26, and a plurality of secondary coils 22
26 to act on the intake valve 1 as a strong driving force to drive the intake valve 1 in the opening direction.

The driving force at the time of the initial driving is applied only for a short time during which the induced current is generated in the secondary coils 22 to 26 after the supply of power to the upper coil 32 is stopped. Therefore, the energizing state of the exciting coils 331 to 361 is switched to the 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 with the progress of the magnetic field, the amount of magnetic flux linked to the secondary coils 22 to 26, that is, the magnetic flux density increases and decreases, so the secondary coil In each of 22 to 26, an induced current is generated in a direction to maintain the state of the magnetic flux. 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 moving magnetic field is reduced, 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 spring 29.

In order to drive the intake valve 1 from the stop state to the closing direction, the traveling direction of the traveling magnetic field may be set to the upward direction, that is, the closing direction. However, at the moment of starting from the stop state, the driving force acting on the intake valve 1 is small because the slip on the traveling magnetic field is large, but the reaction force of the spring 29 is small.
The armature 2 immediately starts moving in the closing direction in order to assist the driving in the closing direction.

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

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

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

Although the embodiments have been described in detail, various different embodiments can be easily configured without departing from the spirit of the invention, and therefore, the present invention is not limited to the specific embodiments described in the claims. You are not restricted to the examples.

(Effects of the Invention) As described above, according to the present invention, in the induction type electromagnetic force valve driving device of the present invention, the 2
The traveling magnetic field is formed by the fixed magnetic poles juxtaposed on the side surface of the secondary coil, and the current induced in the secondary coil reciprocally drives the intake and exhaust valves by the electromagnetic force received from the traveling magnetic field. Even if it changes, the driving force does not change, so that stable opening / closing control can be performed. In addition, at the time of initial driving, a magnetic field in the same direction is applied to the secondary coil from the outer circumference, and the end face of the movable magnetic pole is Since the current induced by the opposed fixed electromagnet is driven by the electromagnetic force received from the magnetic field in the same direction, the driving force acts on all the secondary coils, and thus a strong driving force can be generated. Since the fixed magnetic pole that forms the traveling magnetic field always faces the movable magnetic pole, the magnetic resistance is reduced, and the amount of heat generated by the exciting coil wound around the fixed magnetic pole is suppressed, thereby preventing disconnection of the exciting coil. You It can provide inductive electromagnetic force valve driving apparatus capable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing a state at the time of initial driving. 1 ... intake valve, 2 ... mover, 3 ... drive unit, 4 ...
... Controller, 5 ... Rotation sensor, 6 ... Load sensor, 22-26 ... Secondary coil, 31 ... Center magnetic pole, 32 ... Top coil, 33-36 ... Magnetic pole, 331-361 ... Exciting coil .

Claims (2)

(57) [Claims] A movable member connected to at least one of an intake / exhaust valve of the engine and capable of reciprocating; a magnetic pole arranged in parallel in the reciprocating direction and always facing an outer peripheral surface of the movable member; An exciting coil wound around the magnetic pole and forming a traveling magnetic field in a reciprocating motion direction in an open state; and an outer circumferential surface of the movable element facing the magnetic pole and parallel to a vertical plane of the moving direction. A fixed electromagnet having a secondary coil, a central magnetic pole facing the upper end surface of the mover, and an upper coil wound therearound, for inducing a current to the secondary coil when the valve is initially driven; Power supply means for supplying electric power to an electromagnet to open and close the valve. 2. The inductive electromagnetic valve driving device according to claim 1, wherein a plurality of said secondary coils are arranged in parallel in a reciprocating direction.