JPH02271011A - Stepping driving device of valve - Google Patents

Abstract

PURPOSE:To perform stable opening/closing operation to the shift of an intake/ exhaust valve by arranging a linear pulse motor at the shaft end of the intake/ exhaust valve. CONSTITUTION:An upper magnetic pole 23 and a lower magnetic pole 33 are arranged specified distance apart in the direction of the reciprocation of an intake valve 1, being connected with the intake valve 1 of an engine 7. An upper coil 22 and a lower coil 32 generate lines of magnetic forces in the upper magnetic pole 23 and the lower magnetic pole 33, respectively. Moreover, plural pieces of permanent magnets 41-44, whose polarities are arranged alternately, are fixed to an engine, opposite to the upper magnetic pole 23 and the lower magnetic pole 33 and at interval different from the interval between the upper magnetic pole 23 and the lower magnetic pole 33. Hereupon, a control unit 5 controls the current application to the coils 22 and 32, and accords the electromagnetic forces, which act between the magnetic poles 23 and 33 and the permanent magnets 41-44, in the specified direction. Hereby, the driving force to the intake valve 1 does not change by the opening/closing shift, so stable opening/closing operation can be done.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve stepping drive device for driving the opening and closing of intake and exhaust valves of an engine using a linear pulse motor disposed at the shaft end of the intake and exhaust valves. .

(Prior Art) In a conventional intake/exhaust valve opening/closing drive device, a camshaft, in which intake and exhaust cams are arranged on a single wooden shaft, is disposed on the top or side of the engine. The crankshaft, which is the output shaft of the engine, is connected to the camshaft by a rotation transmission means such as a belt, and the camshaft is rotationally driven in synchronization with the crank angle. Due to this rotational drive, the cam surface of the camshaft pushes the shaft end surface of the intake and exhaust valves via a link mechanism such as a rocker arm or a bushing rod. The intake and exhaust valves are always held in a closed state by a spring, and are opened by pushing the end face of the valve shaft.

Alternatively, an intake camshaft with an intake cam and an exhaust camshaft with an exhaust cam can be installed at the top of the engine, and the cam surface of the intake camshaft connects the shaft end surface of the intake valve, and The intake and exhaust valves are opened by directly pushing the shaft end face of the exhaust valve with the cam surface.

(Problems to be Solved by the Invention) Such a conventional intake/exhaust valve opening/closing drive device requires a camshaft and a link mechanism to be attached to the engine, which increases the size of the engine. Additionally, since the camshaft and link mechanism are driven by the output shaft of the engine, a portion of the engine output is consumed due to frictional resistance when driving the camshaft and link mechanism, reducing the effective output of the engine. . In addition, the opening and closing timing of the intake and exhaust valves cannot be changed while the engine is running, and the valve opening and closing timing is adjusted according to a predetermined engine speed. decreases.

In order to solve the above problem, a device for opening and closing intake and exhaust valves using electromagnets instead of camshafts is disclosed in Japanese Patent Laid-Open No. 58-183805 or Japanese Patent Laid-Open No. 61-7.
It is described in Publication No. 6713. However, in the configuration of the electromagnet disclosed in the device described in the above two publications, the distance between the electromagnet and the magnetic body changes as the intake and exhaust valves are driven, and the electromagnetic force changes rapidly, so the operation of the intake and exhaust valves changes. has the disadvantage of being extremely unstable.

The present invention has been made in view of the above points, and the opening and closing drive of the intake and exhaust valves of the engine is performed by a linear pulse motor disposed at the shaft end of the intake and exhaust valves, instead of using a camshaft. The present invention aims to provide a valve stepping drive device that performs stable opening and closing operations with respect to movement of intake and exhaust valves.

(Means for Solving the Problems) According to the present invention, two movable magnetic poles connected to intake and exhaust valves of an engine and arranged at a predetermined interval apart in the reciprocating direction of the valves, and magnetic lines of force in each of the movable magnetic poles. generate 2
a plurality of permanent magnets facing the movable magnetic pole and fixed to the engine and having polarities arranged alternately at intervals different from the spacing of the movable magnetic pole; It is possible to provide a stepping drive device for a valve, which includes an energization control means for aligning electromagnetic force acting between the present invention and the permanent magnet in a predetermined direction.

(Function) In the valve stepping drive device of the present invention, since the opening and closing of the intake and exhaust valves is performed by a linear pulse motor disposed at the shaft end of the intake and exhaust valves, the driving force for the intake and exhaust valves changes with the opening and closing movements. It has the effect of allowing stable opening/closing operations.

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

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

Reference numeral 7 denotes an engine, and a rotation sensor 71 is disposed near the output shaft of the engine 7 to detect the rotation speed and crank angle of the output shaft and convert them into signals. Intake and exhaust valves for controlling the opening and closing of intake and exhaust ports are disposed within the engine 7, and the intake valves will mainly be described below.

Reference numeral 1 denotes an intake valve made of a high-strength, lightweight material such as ceramics, and the shaft portion of the intake valve 1 is freely supported in the axial direction by a valve guide 12. A valve seat 13 is arranged at the intake port which is the end point of the intake pipe,
- The umbrella portion of the intake valve 1 and the valve seat 13 are in close contact to close the intake port. Further, an upper magnetic body 21 having an upper magnetic pole 23 and a lower magnetic body 31 having a lower magnetic pole 33 are fitted to the outer periphery of the shaft end of the intake valve 1. The upper magnetic pole 23 and the lower magnetic pole 33 are made of resin. They are arranged in parallel at a predetermined pitch via shims 14 consisting of, etc.

Permanent magnets 41, 42, 43, and 44 are arranged on the outer periphery of the upper magnetic pole 23 and the lower magnetic pole 33, and the opposing magnetic poles are arranged in order from the permanent magnet 41 to 5.
-N-5-Alternately with the N pole in the direction of movement of the intake valve and via spacers 46 made of magnetic material
3 and the lower magnetic pole 33 are arranged in parallel at a pitch that is 1.5 times that of the lower magnetic pole 33. (The pitch of the permanent magnets 41, 42, 43, and 44 is P.) Furthermore, an upper magnetic passage 45 made of a magnetic material and facing the side surface of the upper magnetic material 21 is connected to the upper part of the permanent magnet 41. A lower magnetic passage 47, which is also made of a magnetic material and faces the side surface of the lower magnetic material 31, is connected to the lower part of the permanent magnet 44.

The upper magnetic passage 45 is provided with an upper coil 22 that generates lines of magnetic force in the upper magnetic body 21 and controls the polarity of the upper magnetic pole 23 . Further, the lower magnetic passage 47 is provided with a lower coil 32 that generates magnetic lines of force in the lower magnetic body 31 and controls the polarity of the lower magnetic pole 33, and a position sensor 6 that detects the 8-movement position of the intake valve 1. The upper magnetic body 21 and the upper coil 22 constitute the electromagnet 2, and the lower magnetic body 31 and the lower coil 32 constitute the lower electromagnet 3. In addition, the lower magnetic body 31 and the valve guide 1
A spring 11 is provided between the intake valve 1 and the intake valve 1 to prevent the intake valve 1 from lowering when the electromagnets 2 and 3 are not in operation.

The output signals of the rotation sensor 71 and the position sensor 6 are input to the control unit 5 via the human output interface 54 . Then, the drive signal for the intake valve 1 is
Similarly, the signal S1 is outputted to the upper coil 22 and the signal S2 is outputted to the lower coil 32 via the human output interface 54.

In addition to the human output interface 54, the control unit 5 has a RAM for temporarily storing data and calculation results.
53. RO that stores programs and various relationship maps
The CPU 51 performs calculations based on programs stored in the M52, the ROM 52, and the control memory 55 that controls the flow of signals within the control unit 5.

Next, the principle of driving the intake valve 1 according to the present invention will be explained using FIG. 2.

FIG. 2 is a detailed view of the drive part. Figures (a) to (f)
) are the upper electromagnet 2, the lower electromagnet 3, and the permanent magnet 41, respectively.
・The right side of 42, 43, and 44 in FIG. 1 is shown. However, the description of the upper coil 22 and the lower coil 32 is omitted.

(a) shows a state in which the intake valve 1 is in the closed position. In this state, both the upper magnetic pole 25 and the lower magnetic pole 33 are set to the N pole due to the signals S1 and S2 output from the control unit 5, and the upper magnetic pole 23 and the permanent magnet 4
1, an attractive force acts between the lower magnetic pole 8i33 and the permanent magnet 41, and a repulsive force acts between the lower magnetic pole 33 and the permanent magnet 42. These three forces are not balanced, and the combined force becomes a force that drives the intake valve 1 upward, but since the intake valve 1 is already seated on the valve seat 13, the upward movement It cannot move any further and is therefore stopped and held in this state.

Next, the signal S2 is inverted to change the N pole of the lower magnetic pole 33 to the S pole. Then, attractive forces act between the upper magnetic pole 23 and the permanent magnet 41 and between the lower magnetic pole 33 and the permanent magnet 42, and the intake valve 1 is moved to the position (b) where the two attractive forces are balanced. is retained. Furthermore, from state (a) to (b)
) is set to a minute amount with respect to the pitch P of the permanent magnets, and is 1/4P in this figure.

From the state of (b), the signal S1 is inverted and the N pole of the upper magnetic pole 23 is changed to the S pole. Then, a repulsive force acts between the upper magnetic pole 23 and the permanent magnet 41 and between the lower 6n pole 33 and the permanent magnet 43, and the upper spot 8i23 and the permanent magnet 4
2 and between the lower lin pole 33 and the permanent magnet 42, the intake valve 1
It is held at position (C) where the two repulsive forces are balanced.

Next, the signal S2 is inverted, and the S pole of the lower magnet 8i33 is changed to the N pole. Then, attractive forces act between the upper magnetic pole 23 and the permanent magnet 42 and between the lower magnetic pole 33 and the permanent magnet 43, and the intake valve 1 is moved to the position (d) where the two attractive forces are balanced. is retained.

Next, the signal S1 is inverted, and the S pole of the upper magnetic pole 23 is changed to the N pole. Then, a repulsive force acts between the upper magnetic pole 23 and the permanent magnet 42 and between the lower magnetic pole 33 and the permanent magnet 44, and between the upper magnetic pole 8i23 and the permanent magnet 43 and between the lower magnetic pole 33 and the permanent magnet. There is a gravitational force between 43 and
The intake valve 1 is held at the position (e) where the two suction forces and the two repulsion forces are balanced.

Then, the signal S2 is inverted, and the N pole of the lower magnet 8i33 is set to S.
Change to pole. Then, the upper magnetic pole 23 and the permanent magnet 43
An attractive force acts between both the lower magnetic pole 33 and the permanent magnet 44, and the intake valve 1 is held at the position (f) where the two attractive forces are balanced.

Note that the movement amounts between (b) to (C) to (d) to (e) to (f) are all 1/2P. Therefore, by controlling the inversion states of the signals S1 and S2, it is possible to control the cardiac position of the intake valve 1.

Next, the uninvented operation will be explained using FIG. 3.

FIG. 3 is a diagram showing the relationship between the crank angle and the position of the intake valve 1. In the figure, the horizontal axis shows the crank angle,
The vertical axis shows the valve position.

When the crank angle detected by the rotation sensor 71 reaches the opening timing of the intake valve 1, the control unit 5 calculates the engine load from the engine 7 rotation speed signal and the accelerator pedal depression signal (not shown), and adjusts the rotation speed. The opening/closing speed and opening degree of the intake valve 1 according to the number and load are R.
The calculation is performed based on the relationship map stored in the OM52. The intake valve 1 is driven in the opening direction by the signals S1 and S2 based on the calculation results, and the above (C) to (f)
After being held at a predetermined opening degree calculated from among the following, it is driven in the closing direction to close the intake port.

In order to reduce the seating impact when the vehicle is closed, the above (
After driving to the position shown in b) and decelerating the speed in the closing direction, the state shown in (a) is reached. Then, the closed state is maintained until the next timing.

When the intake valve 1 is in the driving state, the position corresponding to the output state of the signals S1 and S2 is compared with the intake position signal from the position sensor 6, and the position corresponding to the output state and the actual position are compared. If they are different, a predetermined operation is performed to return to the closed state and a failure diagnosis is performed.

Although an embodiment of the present invention has been described above, mainly regarding an intake valve, it is clear that the drive device according to the present invention can be similarly applied to a zero-air valve. It should be noted that since various different embodiments can be easily constructed without departing from the spirit of the invention, the present invention is not limited to specific embodiments other than the limitations set forth in the claims.

(Effects of the Invention) As explained above, according to the present invention, the opening/closing drive of the intake and exhaust valves of the engine is performed not by the camshaft but by the linear pulse motor disposed at the shaft end of the intake and exhaust valves. Since the driving is performed, the driving force for the intake and exhaust valves does not change due to opening/closing heart motion, and it is possible to provide a valve stemming driving device that can perform stable opening/closing operations.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the driving principle of the intake valve, and FIG. 3 is a diagram showing the relationship between the crank angle and the position of the intake valve 1. be. DESCRIPTION OF SYMBOLS 1... Intake valve, 2... Dobe electromagnet, 3... Lower magnet, 5... Control unit, 6... Position sensor, 7... Engine, 41, 42, 43, 44
...Permanent magnet, 71... Rotation sensor. Patent applicant: Isume Ceramics Research Institute Co., Ltd.
Patent Attorney Minoru Tsuji 2nd (A;') (e) ((:l')
figure

Claims (3)

[Claims] (1) A plurality of movable magnetic poles connected to intake and exhaust valves of the engine and arranged at predetermined intervals in the reciprocating direction of the valves; and a coil fixed to the engine and controlling the polarity of each of the movable magnetic poles. , a plurality of permanent magnets with alternating polarity, which are fixed to the engine facing the movable magnetic poles and arranged at intervals different from the spacing of the movable magnetic poles; 1. A stepping drive device for a valve, comprising: energization control means for aligning electromagnetic forces acting in a predetermined direction. (2) The valve stepping drive device according to claim (1), wherein the intake and exhaust valves are made of ceramics. (3) The valve stepping drive device according to claims (1) and (2), wherein the number of movable magnetic poles is two.