JP2982009B2 - Electromagnetic valve drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electromagnetic force valve driving device for opening and closing an intake valve or an exhaust valve (hereinafter, referred to as an intake / exhaust valve) of an engine by an electromagnetic force generated by an electromagnet. About.

(Prior Art) As a conventional intake / exhaust valve opening / closing drive device, a camshaft in which a cam for an intake valve and a cam for an exhaust valve are arranged on one shaft is arranged on an upper portion or a side surface of an engine. The camshaft and the crankshaft, which is the rotation axis of the engine, are connected by a rotation transmission means such as a belt, and the camshaft is driven to rotate in synchronization with the engine rotation phase. The shaft end face of the valve is pushed from the cam surface of the camshaft via a link mechanism such as a rocker arm or a pushing rod. The intake / exhaust valve is always kept closed by a spring, and is opened by pushing the valve shaft end face.

Alternatively, an intake camshaft with a cam for the intake valve and an exhaust camshaft with a cam for the exhaust valve are arranged at the upper part of the engine, the shaft end of the intake valve on the cam surface of the intake camshaft, and The intake and exhaust valves are opened by directly pushing the shaft end of the exhaust valve with the cam surface of the exhaust camshaft.

In such a conventional intake / exhaust valve opening / closing drive device, the camshaft and the link mechanism must be attached to the engine, so that the size of the engine is increased. 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 due to frictional resistance when driving the camshaft and the link mechanism, and the effective output of the engine is reduced. Also, the opening / closing timing of the intake / exhaust valve cannot be changed during the operation of the engine, and the valve opening / closing timing is adjusted according to the predetermined engine speed. Power and efficiency are reduced.

In order to solve the above problem, an apparatus that opens and closes an intake / exhaust valve by an electromagnetic force not by a camshaft but by an electromagnet is disclosed in Japanese Patent Application Laid-Open No. 58-183805 or
-76713.

(Problems to be Solved by the Invention) The configuration of the electromagnet disclosed by the above two publications is as follows.
The suction / exhaust valve is driven by the attraction force acting between the movable magnetic pole connected to the intake / exhaust valve and the magnetic pole of the electromagnet. Therefore, at the time when the attractive force starts to act on the movable magnetic pole, the distance between the magnetic pole of the electromagnet and the movable magnetic pole is maximum. Since the electromagnetic force is inversely proportional to the square of the distance, the distance is minimum at the time when the attraction force starts to act, and the distance between the magnetic pole of the electromagnet and the movable magnetic pole increases with the movement of the valve. Therefore, the acceleration immediately after the start of the movement of the movable magnetic pole is small, and increases with the movement.
Then, the extended opening area of the valve interlocking with the movable magnetic pole with the passage of time becomes small.

Also, as described in JP-A-61-76713, even when a braking force is applied to the movable magnetic pole immediately before the valve is seated in order to alleviate the impact when the valve is seated, the electromagnet and the movable magnetic pole are Is large, the braking force is small, and the seating impact cannot be sufficiently reduced.

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 driving device in which the driving force acting on the valve at the start of movement of the intake / exhaust valve and at the time of seating is maximized. .

(Means for Solving the Problems) In an electromagnetic force valve driving device which is connected to at least one of an intake / exhaust valve of an engine and has a movable magnetic pole capable of reciprocating motion, an upper magnetic pole opposed to one end of the movable magnetic pole is provided. A first electromagnet including a yoke member having a lower magnetic pole communicating with the upper magnetic pole and facing the other end of the movable magnetic pole, and a second electromagnet including a magnetic pole facing one end of the upper magnetic pole and the movable magnetic pole And a third electromagnet having two magnetic poles respectively opposed to the other ends of the upper magnetic pole and the movable magnetic pole.

(Operation) In the electromagnetic valve driving apparatus of the present invention, the driving in the opening direction and the braking at the time of seating of at least one of the intake and exhaust valves are performed by the repulsive force of the electromagnetic force. The acceleration at the time becomes large, and thus the extended opening area of the valve becomes large, so that the intake and exhaust resistance decreases.

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

FIG. 1 is an overall configuration diagram showing a driving device according to the present invention.

The engine 6 has an intake valve that opens and closes an intake port of a cylinder and an exhaust valve that opens and closes an exhaust port. Hereinafter, the intake valve will be mainly described.

The intake valve 4 is slidably mounted on a cylinder head of the engine 6 by a valve guide 41 in the axial direction of the intake valve 4.
It is seated on a valve seat 42 arranged at the outlet of the intake pipe 43, and the intake port is closed. A movable magnetic pole 3 made of a magnetic material is attached to a shaft end of the intake valve 4 by a fixture 32. The movable magnetic pole 3 has an end magnetic pole 31 protruding in a circumferential shape at the axial end side end. An upper electromagnet 1 serving as a second electromagnet is disposed close to the upper side of the end magnetic pole 31, and the upper electromagnet 1 has a central magnetic pole 12 facing the end magnetic pole 31 and a central magnetic pole 12. It comprises an opposing outer magnetic pole 13 and an upper coil 11 for generating lines of magnetic force on the central magnetic pole 12 and the outer magnetic pole 13. Also, a lower electromagnet 2 serving as a first electromagnet and the lower electromagnet 2
Inside, a central electromagnet 7 serving as a third electromagnet is provided around. The lower electromagnet 2 includes the outer peripheral magnetic pole 13 and the end magnetic pole.
It comprises an upper magnetic pole 23 facing the lower magnetic pole 31, a lower magnetic pole 22 facing the outer peripheral surface of the movable magnetic pole 3, and a lower coil 21 for generating lines of magnetic force on the upper magnetic pole 23 and the lower magnetic pole 22. The middle electromagnet 7 held inside the lower electromagnet 2
An upper magnetic pole 73 facing the upper magnetic pole 23, a lower magnetic pole 72 facing the outer peripheral surface of the movable magnetic pole 3, and a middle coil 71 for generating lines of magnetic force on the upper magnetic pole 73 and the lower magnetic pole 72.

The upper coil 11, the lower coil 21, and the middle coil 71
Are connected to an input / output interface 54 inside the control unit 5. The input / output interface 54
In addition to the upper coil 11 and the lower coil 21, a rotation sensor 61 provided near the output shaft of the engine 6 is connected.

The control unit 5 includes, in addition to the input / output interface 54 for controlling input and output of signals to and from the outside, a ROM 52 for storing programs and data in advance, a CPU 51 for performing calculations under the programs stored in the ROM 52, and an input signal. And a control memory 55 for temporarily controlling the flow of signals in the control unit 5.

 Next, the operation of the present apparatus will be described.

FIG. 2 is an operation explanatory view showing the upper electromagnet 1, the middle electromagnet 7, and the lower electromagnet 2, which are valve driving units. still,
The hatched lines indicating the cross section are omitted.

Normally, as shown in FIG.
On the other hand, the central magnetic pole 12 is energized so as to generate an N pole, the outer magnetic pole 13 is energized so as to generate an S pole, and the lower coil 21 is also provided with an S pole for the lower magnetic pole 22 and an N pole for the upper magnetic pole 23. Is supplied so that Since the end magnetic pole 31 faces the upper magnetic pole 23, the end magnetic pole is generated by the N pole generated in the upper magnetic pole 23.
An S pole is attracted to 31. The central magnetic pole 12 and the end magnetic pole 31 are opposed to each other, and an attractive force acts between the N pole of the central magnetic pole 12 and the S pole of the end magnetic pole 31 to pull the intake valve 4 upward. Therefore, the intake valve is held while sitting on the valve seat 42.

When the rotation phase of the engine 6 detected by the rotation sensor 61 becomes the opening timing of the intake valve 4, the direction of energization to the upper coil 11 is reversed as shown in FIG.
Current is supplied to generate an S pole at 12 and an N pole at the outer magnetic pole 13. At the same time, the energization is reversed so that the upper magnetic pole 73 and the lower magnetic pole 72 are slightly energized with respect to the central coil 71 such that an S pole and an N pole are slightly generated. Then, a repulsive force acts between the center magnetic pole 12 and the end magnetic pole 31 facing each other, and the intake valve 4 is driven downward, that is, in the opening direction. Since the distance between the central magnetic pole 12 and the end magnetic pole 31 at the start of the driving is the smallest in the vertical movement of the intake valve 4, the downward driving force due to the rejection of the electromagnetic force becomes the maximum.

When both the intake valve 4 and the movable magnetic pole 3 are driven downward by the repulsive force, the distance between the end magnetic pole 31 and the upper magnetic pole 73 is reduced, so that the action between the end magnetic pole 31 and the upper magnetic pole 73 is effected. Repulsive force increases. Then, at a position near the upper magnetic pole 73 where the repulsive force between the center magnetic pole 12 and the end magnetic pole 31 and the repulsive force between the upper magnetic pole 73 and the end magnetic pole 31 are balanced, the end magnetic pole 31 stops. I do.

When the first set time has elapsed since the opening timing,
As shown in (c), the energization amount to the middle coil 71 is increased, the S pole of the upper magnetic pole 73 and the N pole of the lower magnetic pole 72 are strengthened, and energization to the upper coil 11 is stopped. Then, the repulsive force between the end magnetic pole 31 and the center magnetic pole 12 disappears, and only the repulsive force from the upper magnetic pole 73 acts. Therefore, the movable magnetic pole 3 and the intake valve 4 are driven upward.

Since the interval between the upper magnetic pole 73 and the end magnetic pole 31 at the time of starting the driving is the smallest in the vertical stroke of the intake valve 4,
The upward driving force due to the rejection of the electromagnetic force is maximized. Then, immediately before the intake valve 4 is seated on the valve seat 42,
That is, at the time when the second predetermined time counted from the lapse of the first predetermined time elapses, the state shown in (b) is set again, the upward moving speed of the intake valve 4 is reduced, and the intake valve 4 The shock when sitting on the valve seat 42 is reduced.

At the point in time when a third set time previously set as the time required for the deceleration elapses, the state is returned to the state shown in (a) again, and an upward suction force is applied to the intake valve 4,
The intake valve 4 is held at a seated position on the valve seat 42. Then, the signal indicating the next opening timing is the rotation sensor
The seated state is maintained until the signal is output from 61.

The first, second, and third set times are stored in advance in the ROM 52 in a relationship table between the set times and the engine speed, and the engine speed of the engine 6 detected by the rotation sensor 61 is stored. From the relation table, and by calculating a set time corresponding to the engine speed.

 The above open / closed state will be described with reference to FIG.

FIG. 3 shows what is called a cam profile curve, in which the horizontal axis represents the time elapsed from the opening timing of the intake valve 4, and the vertical axis represents the movement amount of the valve. The curve in the figure shows the change in the amount of movement of the intake valve over time. Among the curves, those indicated by solid lines are those according to the apparatus of the present invention, and those indicated by broken lines are those according to the conventional apparatus using electromagnets.

In the conventional device shown by the broken line, the valve is driven by the attraction force of the electromagnetic force. Therefore, the attraction force is minimum at the start of the operation, and the working distance of the electromagnetic force decreases with the movement of the valve. Power increases. Therefore, the acceleration immediately after the start of the movement is small.

On the other hand, in the device of the present invention, as described above, the acceleration immediately after the start of the valve movement is large. The area surrounded by the profile curve and the abscissa indicates the extended opening area of the valve, and the device of the present invention is larger than that of the conventional device only in the shaded portion. Therefore, the device of the present application has smaller intake and exhaust resistance at the opening of the intake and exhaust valve than the conventional device, and the performance of the engine 6 can be improved.

In addition, in the ROM 52, in addition to the relation table between the set time and the engine speed, a relation map between the engine speed and the valve opening timing is stored in advance, and the valve opening timing with the change in the engine speed is stored. , The output and efficiency of the engine can be improved in the entire range of the engine speed. In addition, cylinder control for increasing or decreasing the number of operating cylinders is also possible by driving or stopping the intake / exhaust valves for each cylinder according to the level of rotation of the engine 6.

In the above description, mainly the intake valve has been described, but it is apparent that the drive device according to the present invention can be similarly applied to the exhaust valve.

As described above, one embodiment of the present invention has been described. However, since various different embodiments can be easily configured without departing from the spirit of the present invention, the present invention is not limited to the specifics described in the claims. The present invention is not limited to the embodiment.

(Effects of the Invention) As described above, according to the present invention, the driving of the intake and exhaust valves in the opening direction and the braking at the time of sitting are performed by the repulsive force of the electromagnetic force. At the same time, the moving speed in the closing direction is reduced, and thus the total opening area of the intake and exhaust valves becomes large,
It is possible to provide an electromagnetic force valve driving device in which intake / exhaust resistance is reduced, high output and excellent fuel consumption rate are provided.

Further, there is an effect that the seating impact of the intake / exhaust valve on the valve seat is reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIG. 2 is an operation explanatory diagram showing a valve driving section, and FIG. 3 is a diagram showing a relationship between a valve moving amount and time. 1 upper electromagnet, 2 lower electromagnet, 3 movable magnetic pole, 4 intake valve, 5 control unit,
6 ... Engine, 7 ... Middle coil.

Claims (1)

(57) [Claims] 1. An electromagnetic valve drive device having a movable magnetic pole reciprocally connected to at least one of an intake / exhaust valve of an engine, an upper magnetic pole facing one end of the movable magnetic pole, and the upper magnetic pole. A first electromagnet comprising a yoke member having a lower magnetic pole in communication with the other end of the movable magnetic pole and a second electromagnet having a magnetic pole facing one end of the upper magnetic pole and the movable magnetic pole; An electromagnetic force valve driving device, comprising: a magnetic pole and a third electromagnet having two magnetic poles facing each other and the other end of the movable magnetic pole.