JP2833000B2 - Engine with solenoid valve drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine with an electromagnetic valve driving device that controls opening and closing of an intake valve and an exhaust valve by electromagnetic force.

[Conventional technology]

Conventionally, an electronically controlled engine that controls an intake valve and an exhaust valve according to the operating state of the engine has been disclosed in, for example,
It is disclosed in JP-A-59-162312. The electronically controlled engine disclosed in this publication controls the opening and closing of an intake valve and an exhaust valve of the engine by electromagnetic force, and inputs an operating state and an atmospheric state of the engine and performs data sampling at every predetermined crank angle. Means for determining the opening / closing timing, lift characteristics, on / off time ratio and injector injection amount of the intake and exhaust valves, means for outputting drive signals to the solenoids of the intake and exhaust valves for each predetermined crank angle, Means for outputting a drive signal to the injector when the intake valve is opened.

[Problems to be solved by the invention]

By the way, the required performance of the engine is required to be more compact and to have a larger output in the future. On the other hand, the engine performance is required to be high torque at low speeds, to improve performance by increasing the amount of work, and to improve fuel efficiency, that is, to have no power loss. At high speeds, not too much torque is required, and the intake air is inertia supercharged. As a result, the power is supplied to the combustion chamber, and output loss due to blow-back of the intake air does not occur. Therefore, it is desired to provide an engine that can increase the torque at a low speed of the engine, increase the amount of work, and increase the suction efficiency by preventing the blow-back of the intake air.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems. The intake valve and the exhaust valve are made of a lightweight material such as a ceramic material so that the intake valve and the exhaust valve can be opened and closed by electromagnetic force. In addition, by controlling the valve lift, the intake and exhaust valves can be controlled independently of the crankshaft rotation, and by controlling them, the degree of freedom in the production of the intake and exhaust valve cal profiles can be increased. The cam lift curve is differentiated between open and closed, and the opening timing of the exhaust valve is controlled in the low engine speed range to increase the amount of work to improve the performance, and to improve the performance of the intake valve. An engine with an electromagnetic valve drive device that controls valve timing when closed to reduce blowback of intake air and improve intake efficiency It is to provide.

[Means for solving the problem]

The present invention relates to an intake valve and an exhaust valve that open and close by an electromagnetic force, an electromagnetic valve driving device that opens and closes each valve by an electromagnetic force, detection means for detecting an engine speed and a crank angle, and each of the detection means. A controller which instructs the electromagnetic valve driving device to control the valve lift, valve timing and opening / closing speed of each valve in response to each detection signal to control opening / closing in an asymmetrical cam profile when the valve is opened and closed; The controller responds to the detection signal of the predetermined engine speed by lowering the maximum valve lift amount of the intake valve at a low speed earlier than at a high speed and at closing the valve timing earlier at a low speed than at a high speed. The present invention relates to an engine with an electromagnetic valve driving device that performs quick valve closing control.

Also, the present invention provides an intake valve and an exhaust valve that open and close by an electromagnetic force, an electromagnetic valve driving device that opens and closes each valve by an electromagnetic force, detection means for detecting an engine speed and a crank angle, and the detection means. Means for instructing the valve lift of each valve, valve timing and opening / closing speed to the electromagnetic valve driving device in response to each detection signal by the means to open and close the valve in an asymmetrical cam profile when the valve is opened and closed. The controller responds to a detection signal of a predetermined engine speed by opening the valve timing of the exhaust valve at a low speed at a lower speed than at a high speed so as to be close to the bottom dead center and at a low valve opening speed at a high speed. The present invention relates to an engine with an electromagnetic valve driving device, which controls valve opening earlier than time.

[Action]

The engine with the electromagnetic valve driving device according to the present invention
With the above configuration, the intake valve has a maximum valve lift earlier at high speed than at high speed, and closes the valve timing earlier at high speed at low speed, and closes rapidly after bottom dead center. Control, thereby reducing the blow-back of the intake air and improving the suction efficiency. Also, this engine with solenoid valve drive is
With respect to the exhaust valve, when the valve timing is opened at a low speed, it is slower than at a high speed so as to be close to the bottom dead center, and when the valve opening speed is low, the valve opening can be controlled faster than at a high speed. Loss of exhaust gas energy in the area A can be prevented, and the amount of work can be increased to improve performance.

〔Example〕

Hereinafter, an embodiment of an engine with an electromagnetic valve driving device according to the present invention will be described with reference to the drawings. In Fig. 1,
3 shows the intake valve and exhaust valve cam profiles for an engine with an electromagnetic valve drive according to the present invention. FIG. 2 shows a PV diagram of the engine with the electromagnetic valve driving device according to the present invention.

In FIG. 1, the crank angle is plotted on the horizontal axis and the valve lift is plotted on the vertical axis, and the intake valve IV and the exhaust valve are plotted.
The valve lift by the EV cam profile is shown. Regarding the cam profile of the exhaust valve EV, a solid line a indicates a high engine speed, a dotted line b indicates a blowdown, and a dashed line c indicates a low engine speed. Regarding the cam profile of the intake valve IV, a solid line d indicates a high engine speed and a chain line e indicates a low engine speed.

Generally, the cam profiles of the intake and exhaust valves, which are opened and closed via a mechanical valve mechanism such as a tappet or a rocker arm in response to the rotation of the crankshaft, have no degree of freedom in the cam profiles.
No difference can be made in the cam lift curve when opening and closing. Normally, the intake valve and the exhaust valve depict the trajectory of the cam profile shown in FIG. 1 as that of the high speed region of the engine rotation. That is, the exhaust valve EV in the high speed region of the engine rotation is represented by a solid line a
As shown in the figure, HEO at the time of valve opening
C. It is about 60 ゜ before, and the HEC when the valve is closed is near after TDC at top dead center. Further, as shown by the solid line d, the intake valve IV in the high-speed region of the engine rotation is such that the valve opening HIO is near the crank angle before the top dead center TDC and the valve closing HI
C is about 60 ゜ after bottom dead center BDC.

In the engine with the electromagnetic valve driving device, the intake valve IV and the exhaust valve EV are lightweight valves made of a ceramic material, and can be opened and closed by electromagnetic force. For example, the electromagnetic valve driving shown in FIG. It is opened and closed by the device. Therefore, the controller 15 can make a difference in the cam lift curve between the time of opening and the time of closing, which means that there is a degree of freedom in the cam profile.

First, in the low speed region of the engine speed, when the exhaust valve EV is opened, the performance improves when the valve opening timing is closer to the bottom dead center BDC.
The valve opening timing is delayed to near BDC, and control is performed so that the opening speed of the exhaust valve EV is fully increased.
As shown in Fig. 1, the LEO when the exhaust valve EV is opened is about 60
カ ム By using a cam profile that delays and rapidly raises the opening speed of the exhaust valve EV, the exhaust gas energy in the area A of the PV diagram can be retained in the combustion chamber as shown in FIG. The amount of work can be increased by that amount, and the performance of the engine can be improved. Also, as the end of the exhaust stroke approaches, the amount of exhaust gas in the combustion chamber is small and the piston rises slowly, so the valve lift may be small and the valve lift may be suppressed. is there.

In the low-speed region of the engine speed, the intake valve IV does not need to have a large valve lift at the beginning of the LIO when the intake valve IV is opened, but the top dead center TDC at which the piston speed is the fastest Later, the rise is steeply controlled, that is, the opening is rapidly controlled so as to become the maximum lift at around 90 ° S. In addition, when the valve is closed, the LIC is controlled so as to close rapidly after the bottom dead center BDC.

However, in the high engine speed region, the intake air is sucked into the combustion chamber by inertia supercharging, and almost no blowback of the intake air occurs. However, in the low engine speed region, if the intake valve IV is opened, A phenomenon occurs in which the intake air once sucked into the combustion chamber flows out to the intake port by blowing back.

Therefore, in order to prevent the occurrence of the blow-back phenomenon of the intake air, the intake valve IV is compared with the high-speed region and the bottom dead center BDC
Later, the valve closes rapidly (with a steep fall). Thereby, the intake air that is blown back through the intake valve IV can be minimized, and the intake efficiency can be improved.

Next, an embodiment of an electromagnetic valve driving device capable of opening and closing the intake valve IV and the exhaust valve EV in the engine with the electromagnetic valve driving device according to the present invention will be described with reference to FIG.

As shown in FIG. 3, the electromagnetic valve driving device is incorporated in the engine 13, and the essential part of the electromagnetic valve driving device is conceptually shown in a state where it is taken out of the engine 13. The fuel injection device 21 for controlling the fuel supplied to the engine 13 has an injection nozzle 12, which penetrates into the intake port 6 from above the cylinder head 3, and the fuel injected from the nozzle hole flows into the cylinder. Spray is introduced.

The fuel injection device 21 is controlled by a command from the controller 15 to inject a predetermined amount of fuel. The rotation sensor 14 is connected to the output shaft of the engine 13.
Is provided to detect the engine speed. The detected value of the engine speed, that is, the rotation signal is input to the controller 15. The intake valve 1 is made of a ceramic material, is guided by a valve guide 16 fixed to the cylinder head 3, and is slidably disposed in a vertical direction.

When the intake valve 1 rises or falls, the valve face 17 of the intake valve 1 is moved to the intake port 6 of the cylinder head 3.
The intake port 6 is opened and closed by coming into contact with or detaching from the valve seat 18 installed in the valve. Therefore, the amount of air taken into the cylinder of the engine 13 is controlled by the opening / closing operation or opening / closing amount of the intake port 6. A mover 19 made of a magnetic material such as soft iron is fixed to the upper end 23 of the intake valve 1.
Is provided with a mover coil 24.

In addition, a stator 25 made of a magnetic material such as soft iron is mounted on the cylinder head 3 above the mover 19, and the stator 25 is provided with a stator coil 20. I have. Therefore, mover coil 24 and stator coil
When the current is turned on / off, the stator 25 is moved
19 is sucked / separated, and the intake valve 1 is driven up and down. In addition, between the valve spring seat 11 formed on the upper surface of the cylinder head 3 and the mover 19,
A valve spring 26 is provided. Therefore, the intake valve 1 is normally closed by the spring force of the valve spring 26.

Furthermore, regarding the intake and exhaust valves that are operated by electromagnetic force, the material constituting the intake and exhaust valves themselves is made of a ceramic material to reduce the weight, and the valve faces of the intake and exhaust valves are reduced. In order to prevent iron powder and the like from adsorbing to the sliding portion of the valve stem 17 and the valve stem 2, it is preferable to manufacture the nonmagnetic ceramic material. However, if iron powder or the like is adsorbed on the sliding portion of the valve face 17 and the valve stem 2, the airtight state of the intake and exhaust ports by the intake valve and the exhaust valve is deteriorated, and the frictional resistance of the sliding portion is increased and seizure is caused. And other undesired conditions occur.

Therefore, in order to operate the intake valve and the exhaust valve by electromagnetic force, a movable element 19 made of a magnetic material is separately provided at the upper end of the intake valve and the exhaust valve. By configuring the intake valve and the exhaust valve as described above, when a controlled current from the controller 15 is supplied to or cut off from the mover coil 24 and the stator coil 20, the stator 25 Withdrawal or suction can be performed against the urging force of the spring 26, so that the intake valve 1 moves down or up, and the valve face of the intake valve 1 can open or close the intake port 6.

In the engine with the electromagnetic valve driving device, the controller 15 receives each detection signal detected by the load sensor 5, the rotation sensor 14, and the position sensor 4, and responds to the detected load signal to generate a valve lifter of the electromagnetic valve driving device. A current can flow through the stator coil 20 and the mover coil 24 in 10 to excite the electromagnet to drive the valve. The load sensor 5 of the engine 13 detects the engine load, and detects the amount of fuel supplied from the injection nozzle 12 of the fuel injection device 21 to the engine 13 or the amount of depression of the accelerator pedal 28. Can be detected. In other words, the load sensor 5 is a sensor for detecting the amount of fuel supplied to the engine 13 and / or
Alternatively, it may be constituted by a sensor for detecting the depression amount of the accelerator pedal 28. Accordingly, by inputting a signal indicating the amount of fuel supplied to the engine 13 and / or the amount of depression of the accelerator pedal 28 to the controller 15 as an engine load signal, the electromagnetic valves of the intake valve and the exhaust valve can be controlled.

Further, the position sensor 4 of the engine 13 detects the position of the stroke of the piston 7, and can detect the position of the troke of the piston 7 by detecting the crank angle. The intake pipe forming the intake port 6 is provided with an intake flow rate sensor 9. The intake flow rate sensor 9 detects, for example, the amount of air hitting a heating wire through a current by a change in the resistance value of the heating wire. A signal from the intake flow rate sensor 9 is input to the intake flow rate processing device 7 and the intake port 6 can be detected. The detected intake air amount is input to the controller 15.

The controller 15 is composed of a microcomputer,
It is provided with a central controller for performing arithmetic processing, various memories for storing arithmetic processing procedures, control means, etc., input / output ports, etc., and receives various signals from the above-described various sensors and the intake flow rate processing device 7 and the like. Then, the processing is performed according to the procedure stored in the memory, and a control command is issued to the electromagnetic coils 20 and 24 for the valve operating mechanism for opening and closing the intake valve 1 and the exhaust valve. Controls opening and closing operations. Further, the controller 15 is not limited to the opening and closing operation of the intake valve and the exhaust valve, and is configured to calculate a valve opening, a valve lift, a fuel injection timing, and the like, and to issue a control command.

In the figure, reference numeral 27 denotes a battery, which serves as a power source for the controller 15, various valves and other coils. In the figure,
Although only the intake valve 1 is shown, this electromagnetic valve driving device is also electromagnetically driven for the exhaust valve, and the exhaust system in which the exhaust valve is arranged is composed of a flow sensor and an exhaust port. No injection nozzle is arranged.

Next, an embodiment of the operation of the engine with the electromagnetic valve driving device according to the present invention will be described with reference to the drawings.

The electromagnetic valve driving device that can be incorporated in the engine with the electromagnetic valve driving device is configured as described above. FIG. 4 is a processing flow chart showing an example of the operation of an engine with an electromagnetic valve driving device that can incorporate the electromagnetic valve control device. In the description of the operation of the engine with the electromagnetic valve driving device, the sign of the intake valve is indicated by IV, and the sign of the exhaust valve is indicated by EV.

In order to control the valve timing and the like of the intake valve IV and the exhaust valve EV in an optimal state, a valve lifter of the intake valve IV and the exhaust valve EV is controlled by a command from the controller 15. Is controlled by electromagnetic force. That is, since the valve lifter 10 can be controlled independently of the rotation of the crankshaft, the amount of intake air and the amount of exhaust gas into the combustion chamber 8, the time of intake of intake air into the combustion chamber 8, and the amount of exhaust gas exhausted from the combustion chamber 8 The control of the time and the valve timing of the intake valve IV and the exhaust valve EV is appropriately adjusted to an optimum state according to the rotation speed of the engine 13, and is controlled so that the engine 13 can operate satisfactorily.

Therefore, the drive of the electromagnetic valve driving device is controlled with the start of the engine 13, and the intake valve IV and the exhaust valve EV are opened and closed. As a first step, by driving the engine 13, it detects the engine rotational speed N _E by the rotation sensor 14, and inputs a detection signal to the controller 15 (step 40).

Further, the crank angle, that is, the stroke position of the piston is detected by the position sensor 4, and the detection signal is input to the controller 15. The controller 15 issues a command to each of the valve lifters 10 of the intake valve IV and the exhaust valve EV in response to each of these detection signals, and the stator coil 20 and the mover coil of each of the valve lifters 10 of the intake valve IV and the exhaust valve EV. The current is supplied to 24, and both valves IV and EV are operated to open and close (step 41).

Engine speed N _E detected by rotation sensor 14
There determines precalculated or greater than a predetermined rotational speed N _E1. That is, with respect to the LEO when the exhaust valve EV is opened, it is preferable that the piston 7 be opened later when the engine 13 is running at a low speed than at the time when the engine 13 is running at a high speed, that is, near the bottom dead center BDC. Regarding the LIC at the time of closing the IV, it is preferable that the valve be closed earlier at low rotation of the engine 13 than at high rotation, that is, near the bottom dead center BDC of the piston. In order to control the engine speed, the rotation speed of the engine 13 at the time of changing the operating state of the intake valve and the exhaust valve is preset to a predetermined rotation speed _NE1 (step 42).

If the engine speed N _E is greater than the predetermined rotational speed N _E1, to the exhaust valve EV can be opened in the normal opening time of HEO in solid line a of FIG. 1, also the intake valve IV
In this case, the exhaust valve EV and the intake valve IV can be operated by electromagnetic force by each valve lifter 10 of the electromagnetic valve driving device, since the valve can be opened by the normal valve opening HIO shown by the solid line d in FIG. Exhaust valve EV to control to perform
Then, the driving condition of each valve lifter 10 of the intake valve IV, that is, the valve driving system is checked (step 43).

If there is no abnormality in the driving conditions of the valve drive system of the intake valve IV and the exhaust valve EV, the intake valve IV and the exhaust valve EV
Is controlled by electromagnetic force at normal valve timing. That is, as shown in FIG. 1, the opening and closing of the exhaust valve EV is controlled along the cam profile a at high speed, and the intake valve IV is controlled along the cam profile d at high speed (step 44).

Further, the engine rotational speed N _E is predetermined when the rotation speed N _E1 is smaller than, the engine 13 is at low rotation, high speed rotation a different operating state, particularly, the intake valves IV and exhaust valves EV The valve lift, valve timing and opening / closing speed are changed to control opening / closing in an asymmetrical cam profile when the valve is opened and closed.

Valve lifters 10 for intake valve IV and exhaust valve EV
To the exhaust valve EV
, The exhaust valve EV is opened when the piston 7 is located near the bottom dead center BDC, and the maximum valve lift is set for the intake valve IV. The intake valve IV and the exhaust valve EV are controlled by electromagnetic force so that the valve closes earlier than at high speed at low speed and closes rapidly after bottom dead center at low speed. Then, the driving conditions of each valve lifter 10, that is, the valve driving system of the electromagnetic valve driving device to be operated are checked (step 45).

If there is no abnormality in the driving conditions of the valve driving system of the intake valve IV and the exhaust valve EV, the intake valve IV and the exhaust valve EV are controlled by electromagnetic force, and as shown in FIG. Along the cam profile c, and for the intake valve IV, the cam profile e at low speed.
(Step 46).

〔The invention's effect〕

The engine with the electromagnetic valve driving device according to the present invention
With the above configuration, the intake valve has a maximum valve lift earlier at high speeds at low speed than at high speeds, and the valve timing closes earlier at high speeds at low speeds and closes rapidly after bottom dead center. Thus, it is possible to reduce the blow-back of intake air to the combustion chamber that occurs at low speed, thereby improving the suction efficiency.

Further, in the engine with the electromagnetic valve driving device, when the exhaust valve is opened at a lower valve timing at a low speed, it is slower than at a high speed so as to be closer to a bottom dead center, and at a low valve opening speed, the valve opens faster than at a high speed. The valve can be controlled, whereby the exhaust gas can be kept in the combustion chamber for a long time, the energy loss of the exhaust gas in the area A shown in FIG. 2 can be prevented, the work amount can be increased, and the performance can be improved. .

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view for explaining an embodiment of an engine with an electromagnetic valve driving device according to the present invention, and FIG. 2 is a schematic explanatory diagram for explaining a PV diagram of the engine with an electromagnetic valve driving device according to the present invention. FIG. 3 is an explanatory view showing an example of an electromagnetic valve driving device incorporated in an engine with an electromagnetic valve driving device according to the present invention, and FIG. 4 is an example of an operation of a control device of an engine incorporating the electromagnetic valve driving device. It is a processing flow figure shown. 1, IV… intake valve, EV… exhaust valve, TDC… top dead center, BDC… bottom dead center, LEO… low speed exhaust valve opening, LIC… low speed intake valve When the valve is closed, a: The cam profile of the exhaust valve at high speed, c: The cam profile of the exhaust valve at low speed, d: The cam profile of the intake valve at high speed, e: The cam of the intake valve at low speed Profile, 4
… Position sensor, 10… Valve lifter, 13… Engine, 14… Rotation sensor, 15… Controller.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 13/02 F01L 9/04 F01L 1/08 F01L 1/34 F01L 13/00 301

Claims (2)

(57) [Claims] 1. An intake valve and an exhaust valve which are opened and closed by an electromagnetic force, an electromagnetic valve driving device which opens and closes each valve by an electromagnetic force, each detecting means for detecting an engine speed and a crank angle, and each of the detecting means A controller which instructs the electromagnetic valve driving device to control the valve lift amount, valve timing and opening / closing speed of each valve in response to each detection signal of the electromagnetic valve driving device to open and close the valve in an asymmetrical cam profile when the valve is opened and closed. The controller responds to the detection signal of the predetermined engine speed by setting the maximum valve lift of the intake valve earlier at high speed than at high speed, and closing valve timing earlier at high speed at low speed. An engine with an electromagnetic valve drive device that performs valve closing control quickly after the start. 2. An intake valve and an exhaust valve which are opened and closed by electromagnetic force, an electromagnetic valve driving device which opens and closes each valve by electromagnetic force, each detecting means for detecting an engine speed and a crank angle, and each of said detecting means. A controller which instructs the electromagnetic valve driving device to control the valve lift amount, valve timing and opening / closing speed of each valve in response to each detection signal of the electromagnetic valve driving device to open and close the valve in an asymmetrical cam profile when the valve is opened and closed. The controller responds to the detection signal of the predetermined engine speed by opening the valve timing of the exhaust valve at a low speed at a lower speed than at a high speed so as to be close to the bottom dead center and at a low valve opening speed at a high speed. An engine with an electromagnetic valve drive that consists of faster opening control.