JP2566474B2 - Electromagnetic valve drive - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic valve drive device that controls opening / closing of an intake / exhaust valve of an engine by a force acting on a current in a magnetic flux generated by a superconducting electromagnet.

(Prior Art) As a conventional opening and closing drive device for intake and exhaust valves, a cam shaft in which intake and exhaust cams are arranged on one shaft is arranged at the top or side of the engine, and rotation transmission of a belt or the like is performed. The crankshaft, which is the rotating shaft of the engine, and the camshaft are connected by means to rotate the camshaft in synchronism with the engine rotation phase. Then, there is one that opens and closes an intake / exhaust valve that is always biased in the closing direction by a spring by pushing the shaft end surface of the valve from the cam surface of the cam shaft via a link mechanism such as a rocker arm or a pushing rod. .

As another device, an intake camshaft with an intake cam and an exhaust camshaft with an exhaust cam are installed on the upper part of the engine, and the cam surface of the intake camshaft is the end face of the intake valve. And the cam surface of the exhaust camshaft directly presses the shaft end surface of the exhaust valve to open the intake / exhaust valve.

(Problems to be Solved by the Invention) In such a conventional intake / exhaust valve opening / closing drive device, a camshaft and a ring mechanism must be attached to the engine, which results in an increase in size of the engine. Further, since the camshaft and the link mechanism are driven by the output shaft of the engine, a part of the engine output is consumed by frictional resistance when the camshaft and the link mechanism are driven, and the effective output of the engine decreases. Also, because the opening / closing timing of the intake / exhaust valve cannot be changed while the engine is running, the valve opening / closing timing is adjusted according to the predetermined engine speed.
When operating at a speed different from the predetermined speed, the output and efficiency of the engine decrease. In order to solve the above problem, a device for opening and closing an intake / exhaust valve by an electromagnetic force of an electromagnet instead of a camshaft is disclosed in JP-A-58-1838.
No. 05 or JP-A No. 61-76713. However, in the structure of the electromagnet in the device disclosed in the above-mentioned 2 gazette, the magnetic body attached to the intake / exhaust valve is attracted by the electromagnet arranged in the moving direction of the intake / exhaust valve, and the intake / exhaust valve is driven by the attractive force. It is a thing. Therefore, since the distance between the electromagnet and the magnetic body changes with the movement of the intake / exhaust valve, the suction force acting on the magnetic body also changes, and there is a problem that the drive of the intake / exhaust valve becomes unstable.

The present invention has been made in view of the above points, and an object of the present invention is to provide an electromagnetic force valve drive device in which the driving force acting on the intake / exhaust valve is stable without being affected by the movement of the intake / exhaust valve. .

(Means for Solving the Problems) According to the present invention, a reciprocating movable drive member, which is connected to an intake / exhaust valve of an engine and is made of a conductor, and a drive member that passes in a direction perpendicular to the reciprocating motion direction of the drive member. A superconducting electromagnet for generating a magnetic flux, an energizing means for energizing the driving body in a direction perpendicular to the reciprocating direction and the passing direction of the magnetic flux, and an energizing control means for controlling an energizing amount and an energizing direction of the energizing means It is possible to provide an electromagnetic force valve drive device having:

(Operation) In the electromagnetic valve drive device of the present invention, a strong magnetic flux generated by the superconducting electromagnet is constantly applied to the conductor interlocking with the intake / exhaust valve, and the current generated by energizing the conductor changes from the magnetic field. Since the received intake / exhaust valve is driven, the driving force acting on the intake / exhaust valve is stabilized without being affected by the movement of the intake / exhaust valve.

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

FIG. 1 is a block diagram showing a driving device according to the present invention.

Of the intake and exhaust valves, the intake valve will be mainly described below.

Reference numeral 1 is an intake valve made of a lightweight and high strength material such as ceramics. The shaft portion of the intake valve 1 is a valve guide 11
Is freely supported in the axial direction by means of which the drive body 12 made of a conductor is connected to the light end. A perspective view of the driving body 12 is shown in the upper right part of the figure. As shown in the drawing, the driving body 12 has a flat plate portion, and the view from A is shown on the left side of the broken line, and the view from B is shown on the right side. Above the intake valve 1, electromagnets including a magnetic pole 14 and a superconducting coil 15 which are opposed to each other on both sides of a flat plate portion of the driving body 12 are arranged. The superconducting coil 15 is formed by cooling a coil made of a superconducting material with liquid helium and further cooling the liquid helium with liquid hydrogen. Then, the hydrogen gas generated by the vaporization of the liquid hydrogen is used as the fuel for the engine 3. Also, the magnetic pole
Brushes 13 are connected to face each other at a right angle to the facing direction of 14. A spring 16 is provided between the driving body 12 and the valve guide 11 to constantly apply a closing bias force to the intake valve 1.

The superconducting coil 15 and the brush 13 are connected to the input / output interface 24 of the control unit 2.
Inside the control unit 2, in addition to the input / output interface 24 for inputting / outputting signals to / from the outside, a ROM 22 that stores a program and data in advance, and a CPU 21 that performs an operation under the program stored in the ROM 22. A RAM 23 for temporarily storing an input signal and a calculation result and a control memory 25 for controlling a flow of signals in the control unit 2 are provided.

A rotation sensor 31 for detecting the rotation speed and crank angle of the engine 3 is arranged near the rotation axis of the engine 3, and the rotation sensor 31 is provided in the output interface.
It is connected to 24 and inputs the rotation speed signal and the crank angle signal to the control unit 2.

 Next, the use of the present invention will be described.

FIG. 2 is a view showing a II cross section in FIG.

The superconducting coil 15 is energized, and the magnetic pole 14 on the left side is the N pole and the magnetic pole 14 on the right side is the S pole in the figure, and the magnetic flux is passed from the right to the left with respect to the driving body 12. Then, the drive body 12 is energized from the upper side to the lower side via the brush 13. Then, according to Fleming's left-hand rule, a driving force acts on the driving body 12 in an upward direction perpendicular to the paper surface. Since the acting direction of the driving force is the opening direction of the intake valve 1, the intake valve 1 is driven in the opening direction.

Next, the relationship between the energization amount and the energization direction and the movement amount of the intake valve 1 will be described.

FIG. 3 is a diagram showing the relationship between the energization amount and the energization direction and the movement amount of the intake valve 1. The upper part of the figure is a profile curve, and the lower part is a diagram showing an energized state. Regarding the energization direction, the energization direction for driving the intake valve 1 in the opening direction is the forward direction, and the energization direction for driving the intake valve 1 in the closing direction is the reverse direction.

Until the opening timing of the intake valve 1, it is energized in the opposite direction and the intake valve 1 is maintained in the closed state. Next, at the closing timing of the intake valve 1, the energization direction is set to the positive direction and the intake valve 1 is driven in the opening direction. When the intake valve 1 moves for a predetermined distance, the energization direction is reversed and the moving speed in the opening direction is reduced. Then, after the intake valve 1 is stopped, it is moved in the closing direction. Intake valve 1 in this state
When the seat is seated, the impact becomes large and the intake valve 1 is destroyed. Therefore, the energization direction is reversed again to reduce the moving speed of the intake valve 1 in the closing direction to mitigate the seating impact. After seating, the intake valve 1 is closed again by reversing the energization direction until the opening timing of the magnetic field.

 Next, the control circuit of the superconducting coil 15 will be described.

FIG. 4 is a diagram showing a control circuit of the superconducting coil 15.

The power source 61 is connected via a switch 62 to a parallel circuit of a fixed resistor 63, a superconducting coil 15 and a variable resistor 65. The intermediate portion of the superconducting coil 15 and the intermediate terminal of the variable resistor 65 are connected via the voltage detector 64.
15 and the variable resistor 65 form a Whitstone bridge. The output terminal of the voltage detector 64 is connected to the alarm signal generator 66.

When the normal conducting portion is generated in a part of the superconducting coil 15, the normal conducting portion rapidly expands over the entire coil, and there is a risk of breaking the coil. Since the Whitstone bridge is formed by each half of the superconducting coil 15 and the variable resistor 65, when the normal conducting part occurs in a part of the superconducting coil 15, the voltage detector 64 causes the normal conducting to occur as a voltage. It detects and outputs a signal to the alarm signal generator 66. The alarm signal generator 66
Outputs an alarm signal in response to a signal from the voltage detector 64, turns off the switch 62, and interrupts energization to the superconducting coil 15. The electric energy stored in the superconducting coil 15 is consumed by the resistor 63,
Is protected and will not be destroyed.

By the way, at the end of the operation of the engine 3, the power supply to the superconducting coil 1 disappears and the electromagnetic force that holds the intake valve 1 closed disappears. Therefore, the spring 16 holds the intake valve 1 closed. The holding force of the spring 16 is set sufficiently small with respect to the driving force in the opening direction.

Incidentally, the relationship map between the engine speed and the valve opening timing is stored in advance in the ROM 22, and the valve opening timing is changed according to the change in the engine speed, so that the engine 3 can be operated in the entire range of the engine speed. Output and efficiency can be improved. Further, it is also possible to perform cylinder control in which the number of operating cylinders is increased / decreased by driving or stopping the intake / exhaust valves for each cylinder in accordance with the increase or decrease in the rotation speed of the engine 3.

Although the operation of one intake valve 1 has been described above, it is also possible to drive a plurality of intake valves with one electromagnet.

FIG. 5 is a diagram showing an embodiment in which a plurality of intake valves are driven by one electromagnet.

Driving body 12 connected to each of a plurality of intake valves 1
, The magnetic flux acting between the magnetic poles 14 passes through each driving body 12 without being attenuated by alternately arranging the magnetic paths 4 with each other. Therefore, by individually controlling the energization state to each driving body 12, The intake valve 1 can be drive-controlled.

Although the embodiments of the present invention have been mainly described with respect to the intake valve, it is apparent that the drive device according to the present invention can be similarly applied to the exhaust valve. In addition, the present invention is not limited to any particular embodiment except for the limitations set forth in the appended claims, as various different embodiments may be readily constructed without departing from the spirit of the invention.

(Effects of the Invention) As described above, a force generated by a constant magnetic flux generated by a superconducting electromagnet is constantly applied to a conductor interlocking with an intake / exhaust valve, and a current generated by energizing the conductor receives a force from a magnetic field. It is possible to provide an electromagnetic valve drive device in which the driving force acting on the intake / exhaust valve is stabilized without being affected by the movement of the intake / exhaust valve because the intake / exhaust valve is driven by the above.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a view showing a II cross section in FIG. 1, and FIG. 3 is a current amount and a current direction and a movement amount of an intake valve. 4 is a diagram showing the control circuit of the superconducting coil, and FIG. 5 is a diagram showing an embodiment in which a plurality of intake valves are driven by one electromagnet. 1 ... intake valve, 2 ... control unit, 12 ...
… Driver, 15… Superconducting coil.

Claims (3)

(57) [Claims] 1. A drive body which is connected to an intake / exhaust valve of an engine and is composed of a conductor and which can freely reciprocate, a superconducting electromagnet which generates a magnetic flux passing in a direction perpendicular to the reciprocating direction of the drive body, and the drive. An electromagnetic valve comprising an energizing means for energizing the body in a direction perpendicular to the reciprocating direction and the passing direction of magnetic flux, and an energizing control means for controlling an energizing amount and an energizing direction of the energizing means. Drive. 2. A plurality of the driving bodies are arranged in parallel in a magnetic flux passing direction, and the energization control means individually controls the energizing amount and the energizing direction for each of the plurality of driving bodies. 1) The electromagnetic valve drive device described above. 3. The superconducting electromagnet is cooled by at least liquid hydrogen, and hydrogen gas generated by vaporization of liquid hydrogen is used as a fuel for the engine (1) or (2). Electromagnetic valve drive device.