JP2707141B2 - Electromagnetic valve drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic force valve driving device that drives an intake valve and an 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 / exhaust bias constantly biased in the closing direction by the spring is 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, an apparatus for opening and closing the intake / exhaust valve by an electromagnetic force by an electromagnet without using a camshaft is disclosed in JP-A-58-183805 or JP-A-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 uses the attracting force to attract the magnetic body. It drives the intake and exhaust valves. By the way, since the attraction force acting on the magnetic body is inversely proportional to the square of the distance between the electromagnet and the magnetic body, in the above-described apparatus, the attraction force changes with the change in the distance, and the drive of the intake and exhaust valves becomes unstable. There's a problem. 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, so On the other hand, only a minimum driving force can be applied.

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 capable of applying 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 magnetic pole connected to at least one of an intake / exhaust valve of an engine and reciprocally movable, and the movable magnetic pole facing a side surface of the movable magnetic pole. A plurality of fixed magnetic poles arranged side by side in the reciprocating direction; a coil wound around the fixed magnetic poles to form the traveling magnetic field in the reciprocating direction when the valve is in an open state; and a fixed magnetic pole provided on the side surface of the movable magnetic pole. A movable magnetic plate which is movable in the reciprocating direction and is opposed to and abuts the end face of the movable magnetic pole;
An electromagnet, comprising: an electromagnet opposed to the movable magnetic plate to attract the movable magnetic plate to drive the movable magnetic pole; and control means for controlling the energized state of the coil and the electromagnet to open and close the valve. A force valve drive can be provided.

(Action) In the electromagnetic force valve driving device of the present invention, a traveling magnetic field is formed by the magnetic poles juxtaposed on the side surface of the secondary coil provided around the mover, and the current induced in the secondary coil is changed from the traveling magnetic field. Since the intake and exhaust valves are reciprocally driven by the received electromagnetic force, the driving force does not change even if the position of the intake and exhaust valves changes, so that stable opening and closing control can be performed. In addition, at the time of the initial drive, the magnetic plate is attracted by the electromagnet, and the magnetic plate is brought into contact with the mover to drive the mover initially, so that a strong driving force can be generated for the intake and exhaust valves.

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, and FIG. 2 is a view taken along the line II-II. In addition, FIG.
It shows a cross section in the direction of the arrow II in the figure. Incidentally, the engine is provided with the intake valve and the exhaust valve as described above, but the drive device according to the present invention can be applied to both the intake and exhaust valves. Therefore, 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, or a heat-resistant non-magnetic alloy. The intake valve 1 is reciprocally supported. When the intake valve 1 is closed, an umbrella portion of the intake valve 1 is seated on a valve seat (not shown) to close an intake port.

A mover 11 is connected to a shaft end of the intake valve 1. The mover 11 has a cylindrical magnetic path 12 and the magnetic path.
It is composed of a plurality of secondary coils 13 provided around the outer peripheral surface of the reference numeral 12. The secondary coil 13 is formed by pouring molten aluminum into a groove formed on the outer peripheral surface of the magnetic path 12. The magnetic path 12 is made of a magnetic material in order to increase the magnetic flux density acting on the secondary coil 13. For example, the magnetic path 12 is formed by arranging magnetic metal amorphous thin plates radially to form a cylindrical shape. However, since the magnetic path 12 serves as a path for the magnetic flux from the fixed magnetic pole 22, which will be described later, it is necessary to arrange the magnetic path so that the magnetic path is secured.

Further, when the engine is stopped, the mover 11 is biased in the closing direction by the spring 1 in order to prevent the intake valve 1 from lowering.

A pair of driving units 2 are arranged on the side surface of the mover 11 with the mover 11 interposed therebetween. The drive unit 2 is composed of a fixed magnetic pole 22 protruding from a core 21 made of a magnetic material and disposed to face the secondary coil 13, and a coil 23 wound around each of the fixed magnetic poles. And a controller 5 to be described later.
, And applies a traveling magnetic field to the secondary coil 13 of the mover 11.

A pair of lower electromagnets 3 is arranged on the side surface of the mover 11 in addition to the drive unit 2. The lower electromagnet 3 includes a lower magnetic pole 31 set below the upper end surface of the mover 11 by a predetermined amount when the intake valve 1 is closed, and a lower coil 32 for exciting the lower magnetic pole 31. .

A magnetic plate 41 that is attracted to the upper electromagnet 4 when the intake valve 1 is seated is disposed above the mover 11. The magnetic plate 41 includes an upper electromagnet 4 and a lower electromagnet 3.
And is reciprocated between both electromagnets, and the lower electromagnet 3
The upper end surface of the mover 11 comes into contact with the movable
11 is driven downward.

The coil 23, the lower coil 32, and the upper electromagnet 4 are connected to the controller 5.

The controller 5 includes a rotation sensor 51 for detecting the number of revolutions of the engine, and a position sensor 52 for detecting the crank angle.
And a load sensor 53 for detecting an amount of depression of an accelerator pedal (not shown).

The controller 5 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 performs calculations in accordance with programs stored in the ROM, It comprises a RAM for temporarily storing data, a control memory for controlling the flow of signals inside the controller 5, and the like.

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

FIG. 3 is a diagram showing a relationship among a valve driving force, a driving speed, and a lift amount.

During the operation of the engine, the depression amount of the accelerator pedal is constantly detected from the load sensor 53 and the rotation speed of the engine is detected from the rotation sensor 51, 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. When the crank angle detected by the position sensor 52 reaches the opening timing of the intake valve 1, the power supply to the upper electromagnet 4 is stopped, and the power is supplied to the lower electromagnet 3 to attract the magnetic plate 41. Then, the magnetic plate 41 comes into contact with the mover 11, so that a strong driving force in the opening direction acts on the intake valve 1 as an initial driving force.

Next, alternating power is supplied to the coil 23 to apply a traveling magnetic field to the mover 11 in the opening direction. Then, the secondary coil 13
The intake valve 1 is continuously driven in the opening direction by the electromagnetic force which the induced current receives from the traveling magnetic field.

When a predetermined amount of time elapses from the opening timing of the crank angle, the traveling speed of the traveling magnetic field is reduced in order to decelerate the intake valve 1, and the movable element 11 is regenerated. And the intake valve 1
Is stopped at the position of the maximum lift amount, and then the traveling direction of the magnetic field is reversed upward, that is, in the closing direction.

By driving the intake valve 1 in the closing direction by the reversed magnetic field, when the crank angle is before the seating, the traveling speed of the magnetic field is reduced again to perform the regenerative operation. Alleviate the impact of

While the intake valve 1 is being opened and closed as described above, the magnetic body 41 is attracted again by the upper electromagnet 4, so that the movable element 11 does not collide with the magnetic plate 41 when the intake valve 1 is seated. .

The bias force of the spring 14 for holding the intake valve 1 in the closed state is set sufficiently small with respect to the electromagnetic force.

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, the traveling magnetic field is formed by the magnetic poles juxtaposed on the side surface of the secondary coil provided around the mover, and the current induced in the secondary coil is generated. Reciprocally drives the intake and exhaust valves by the electromagnetic force received from the traveling magnetic field,
Even if the position of the intake / exhaust valve changes, the driving force does not change, so that stable opening / closing control can be performed. Also,
At the time of initial drive, the magnetic plate is attracted by the electromagnet, and the magnetic plate is brought into contact with the mover to drive the mover initially, so that an electromagnetic force valve capable of generating a strong driving force for the intake and exhaust valves. A drive device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a view taken in the direction of arrows II-II, and FIG. 3 is a diagram showing a relationship among valve driving force, driving speed and lift amount. 1 ... intake valve, 2 ... drive unit, 3 ... lower electromagnet,
4 ... upper electromagnet, 5 ... controller, 11 ... mover, 13 ... secondary coil, 22 ... fixed magnetic pole, 41 ... magnetic plate.

Claims (3)

(57) [Claims] A movable magnetic pole connected to at least one of an intake / exhaust valve of an engine and capable of reciprocating movement, and a plurality of movable magnetic poles opposed to side surfaces of the movable magnetic pole and arranged in parallel in the reciprocating direction of the movable magnetic pole. A fixed magnetic pole, a coil wound around the fixed magnetic pole to form the traveling magnetic field in the reciprocating direction when the valve is in an open state, a secondary coil provided around a side surface of the movable magnetic pole and facing the fixed magnetic pole, A movable magnetic plate that is movable in the direction and faces and contacts the end surface of the movable magnetic pole, an electromagnet that faces the movable magnetic plate and attracts the movable magnetic plate to drive the movable magnetic pole, and a state of energization of the coil and the electromagnet Control means for controlling the opening and closing of said valve. 2. An electromagnetic valve driving device according to claim 1, wherein said electromagnet operates at an initial drive of said valve. 3. The electromagnetic valve driving device according to claim 1, wherein a plurality of said secondary coils are arranged in a reciprocating direction and are provided with a driving force by an induced current and a traveling magnetic field of the primary coil. .