JPH03182607A - Operating position detecting type electromagnetic force valve drive unit - Google Patents

Abstract

PURPOSE:To control the change-over of an intake/exhaust valve accurately by detecting self-induced counter-electromotive force being lower than the specified value to control the current applied state to coils. CONSTITUTION:The magnetic passage 21 of a movable piece 2 is connected to an intake valve 1 and reciprocated. The magnetic poles 32 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 31 are wound on the magnetic poles 32, and secondary coils are provided at the peripheral surface of the magnetic passage 21. Hereupon, an electromotive force detecting device 33 detects self-induced counter-electromotive force generated at the exciting coils 31 being lower than the specified value. When the current applied state to the exciting coils 31 is controlled by a controller 4 on the basis of a signal from the electromotive force detecting device 33, a progressive magnetic field is formed by the magnetic poles 32 lined up at the side faces of the secondary coils 22, and a current induced to the secondary coils 22 reciprocates the intake valve 1 by electromagnetic force received from the progressive magnetic field. The intake valve 1 can be therefore controlled in change-over with further accuracy.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention detects the operating position of an intake and exhaust valve of an engine, and detects the operating position of the intake and exhaust valve by electromagnetic force based on the detected position signal. The present invention relates to a detection type electromagnetic force valve driving device.

(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/closing timing of the intake and exhaust valves cannot be changed while the engine is running, the valve opening/closing timing must be adjusted in accordance with a predetermined engine speed. Therefore, there is a problem in that the output and efficiency of the engine decrease 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 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. 61-78713. 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 attraction force acting on the magnetic body is inversely proportional to the square of the distance between the tIit1 stone and the magnetic body, there is a problem in that the attraction force changes as the distance changes, making the driving of the intake and exhaust valves unstable. Furthermore, a strong accelerating force must be applied to the intake and exhaust valves C at the start of driving, 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 the minimum driving force can be applied.

Furthermore, in the device that drives the intake and exhaust valves using electromagnetic force, the intake and exhaust valves are always driven in a non-contact state.
There is no guarantee that the actual opening/closing position and speed are the same as the set state.

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, with the driving force acting on the intake and exhaust valves being unaffected by the movement of the intake and exhaust valves. An attempt is made to provide an actuation position detection type electromagnetic force valve drive device that more accurately controls the opening and closing of intake and exhaust valves by detecting the open/close state of the valve and feeding back the detected open/close state to the intake/exhaust valve drive IIJiO device. It is something to do.

(Means for Solving the Problems) According to the present invention, a movable element connected to an intake and exhaust valve of an engine and capable of reciprocating, magnetic poles facing the outer peripheral surface of the movable element and arranged in parallel in the reciprocating direction; A coil is wound around the magnetic pole to form a traveling magnetic field in a reciprocating direction, a secondary coil is installed around the outer peripheral surface of the movable element facing the magnetic pole, and a back electromotive force due to self-induction generated in the coil is provided. It is characterized by having an actuation position detection means for detecting that the value is below a predetermined value, and an energization control means for controlling the energization state of the coil based on the signal from the operation detection means and driving the intake and exhaust valves to open and close. It is possible to provide an actuation position detection type electromagnetic force valve driving device.

(Function) In the operating position detection type electromagnetic force valve driving device of the present invention, a traveling magnetic field is formed by the m poles arranged in parallel on the side surface of the secondary coil surrounding the movable element, and the magnetic field is induced in the secondary coil. Since the intake and exhaust valves are reciprocated by the electromagnetic force received from the traveling magnetic field of the current, 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, since the open/close state of the intake and exhaust valves that are driven to open and close in a non-contact state is detected, the operation of the intake and exhaust valves can be controlled according to settings by feeding back the detected open/close state to the opening/closing control device. can.

(Embodiment) An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 341 is a block diagram showing the configuration of the 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 intake valve will mainly be described below.

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

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 1 .

The movable element 2 must be as light as possible in order to reduce the reciprocating inertial mass, and therefore the magnetic passage 21 is formed in a thin cylindrical shape. A plurality of secondary coils 22 are provided around the outer peripheral surface of the magnetic path 21. The secondary coil is formed by pouring molten aluminum into a groove 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, for example, amorphous thin plates of magnetic metal are arranged radially, or ferromagnetic material such as nickel-chromium alloy is formed into a cylindrical shape. This is what I did.

The movable element 2 is connected to the shaft end of the intake valve 1 via a stopper stopper 23 made of hard plastic.

Further, a spring 24 is provided between the valve guide 12 and the movable element 2 to prevent the intake valve 1 from falling when the engine is stopped.

A driving section 3 is arranged around the movable element 2. The drive unit 3 includes a plurality of magnetic poles 32 facing the secondary coil 22 and disposed around the outer peripheral surface of the movable element 2, and an excitation coil 31 wound around each of the magnetic poles 32. . A cylindrical projection 5fI pole 35 is formed at the center of the core 34, which serves as a path for the magnetic flux passing through the magnetic pole 32, and is inserted into the interior of the movable element 2. Since the protruding magnetic poles 35 act as a path for the magnetic flux acting on the movable element 2, the magnetic resistance when the magnetic flux passes can be reduced.

The excitation coil 31 is connected to the controller 4 via an electromotive force detection device 33, and receives power from the controller 4 via the electromotive force detection device 33. Further, the electromotive force detection device 33 is connected to the controller 4 and outputs a detection signal to the controller 4 when it detects that the electromotive force generated by self-induction in the excitation coil 31 is less than a predetermined value.

In addition to the above, 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). There is.

The controller 4 includes an input/output interface that controls the supply of power and power for the detection 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 CPU that executes calculations based on the programs stored in the ROM. 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 rotation sensor 5 detects the engine rotation speed, and a preset relationship map is used to detect the intake air that corresponds to the amount of depression and rotation speed. 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,
The intake valve 1 is driven to open and close by supplying alternating power to the excitation coil 31 and using the magnetic field formed by the magnetic flux from the magnetic pole 32 as a traveling magnetic field.

When the crank angle reaches the opening timing of the intake valve 1, the energization state of the excitation coil 31 is switched to downward alternating power in the figure, and a downward traveling magnetic field is applied to the secondary coil 22.

When the magnetic flux acting on each secondary coil 22 decreases as the magnetic field advances downward, an induced current is generated in each secondary coil 22 in a direction that maintains the magnetic flux. However, at the time when the induced current is generated, the magnetic field has already advanced, and the induced current flows inside the magnetic field. Then, the current induced in the secondary coil 22 receives a downward electromagnetic force from the magnetic field. Therefore, the intake valve l
is driven downward.

Excitation coil 31 is used to drive intake valve 1 in the closing direction.
It is sufficient to reverse the alternating direction of the alternating power supplied to the intake valve 1 to form an upward traveling magnetic field.Also, when the intake valve 1 is seated, the upward traveling speed of the magnetic field is decelerated to prevent the intake valve 1 from seating. Slow down and sit gently.

Among the above drive $lI controls, the downward drive will be explained.

FIG. 2 is a diagram showing an example of energizing the excitation coil 31.

In the figure, a to d indicate the state of energization to a plurality of excitation coils 31 sequentially from the top of the excitation coil 31 shown in FIG. 1.

As shown in this figure, alternating power is sequentially applied to the wJ magnetic coil 31 in a pulsed manner. When the pulsed power is turned off, a back electromotive force is generated in each excitation coil 31 due to self-induction. The back electromotive force is proportional to the inductance of each exciting coil 31, but if the secondary coil 22 is located at a position facing the magnetic pole 32 around which the exciting coil 31 is wound, the inductance increases and the back electromotive force increases. Voltage increases. Conversely, when the movable element 2 moves and the secondary coil 22 facing the M1 pole 32 does not exist, the voltage of the back electromotive force drops. The voltage difference of the back electromotive force is detected by an electromotive force detection device 33, and the actual position of the intake valve 1 is detected based on the level of the back electromotive force voltage, which is fed back to the controller 4 to correct the progress state of the magnetic field. The opening and closing of the intake valve 1 can be controlled in a closed loop.

By the way, in the above embodiment, the mover 2 is formed into a hollow cylindrical shape in order to increase the circumferential length of the secondary coil 22.
There is no problem even if it has a solid cylindrical shape.

The bias of the spring 24 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. The examples are not intended to be limiting.

(Effects of the Invention) As explained above, according to the present invention, a traveling magnetic field is formed by the magnetic poles arranged in parallel on the side surface of the secondary coil surrounding the movable element, 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, since the open/close state of the intake and exhaust valves that are driven to open and close in a non-contact state is detected, the operation of the intake and exhaust valves can be controlled according to settings by feeding back the detected open/close state to the opening/closing control device. It is possible to provide an electromagnetic force valve drive device that detects the operating position.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing an example of energizing the excitation coil 31. DESCRIPTION OF SYMBOLS 1... Intake valve, 2... Mover, 3... Drive unit, 4... Controller, 5... Rotation sensor, 6...
- Load sensor, 22... Secondary coil, 31... Excitation coil, 32... Paramagnetic pole, 33... Electromotive force detection device. 1st Figure 51

Claims (3)

[Claims] (1) A movable element that is connected to the intake and exhaust valves of the engine and can freely reciprocate; a magnetic pole that faces the outer peripheral surface of the movable element and is arranged in parallel in the reciprocating direction; and a magnetic pole that is wound around the magnetic pole to form a traveling magnetic field in the reciprocating direction. a secondary coil disposed in a ring on the outer circumferential surface of the movable element facing the magnetic pole; and an actuation position sensor for detecting that a self-induced back electromotive force generated in the coil is below a predetermined value. and energization control means for controlling the energization state of the coil based on the signal from the operation detection means and driving the intake and exhaust valves to open and close. (2) The operating position detection 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 of the movable element. (3) The operating position detection type electromagnetic force valve driving device according to claim (1), wherein the movable element is made of a magnetic material.