JP2001115864A - Control device for electromagnetically driven exhaust valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform control of an electromagnetically driven type exhaust valve for an engine by a proper control system. SOLUTION: In an engine provided with two electromagnetically drive type exhaust valves at each cylinder, in a low load state, two exhaust valves are alternately driven during a very low temperature (S1-S3). During low temperature operation, only a specified one exhaust valve is driven (S1, S2→S4, S5). During medium load operation, driving is effected by making the opening timings of two exhaust valves lag from each other (S1→S6, S7). During high load operation, the two exhaust valves are simultaneously driven (S1→S6, S8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine provided with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing of each cylinder. It relates to a switching technique.

[0002]

2. Description of the Related Art In a vehicle engine, it has become common to provide two intake / exhaust valves for each cylinder in response to a demand for high output. However, for exhaust valves, two valves are simultaneously opened and closed. In addition to the usual usage method, only a specific one of the two exhaust valves is opened during low load operation such as idling, and the other exhaust valve is kept closed so that the exhaust blow-through amount is reduced. In order to improve drivability, there is a method in which the operability is improved (see Japanese Patent Application Laid-Open No. 58-44234).

On the other hand, for a vehicle engine, an electromagnetically driven intake / exhaust valve has been proposed, and the opening / closing timing can be variably controlled to obtain optimal intake / exhaust characteristics.

[0004]

Even in the case where the two electromagnetically driven exhaust valves are provided for each cylinder, the operation of one of the exhaust valves is stopped under a specific operating condition as in the conventional example. A method of driving only one exhaust valve is conceivable.

[0005] However, in the conventional method of stopping the operation of one of the exhaust valves in response to a request for only the exhaust performance,
The optimum control method was not adopted because it did not take into account the wear of the exhaust valve and the valve seat, the power consumption in the electromagnetic drive type, the characteristic difference, and the like.

The present invention has been made in view of such a conventional problem. In an engine provided with two electromagnetically driven exhaust valves for each cylinder, the most suitable for the two exhaust valves is provided. An object of the present invention is to provide a control device for an electromagnetically driven exhaust valve that is controlled by a control method.

[0007]

For this reason, the present invention according to claim 1 is an engine provided with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing for each cylinder. The control method of the valve is switched based on a condition including a temperature state of the engine.

According to the first aspect of the present invention, the control method of the two exhaust valves is switched based on a condition including a temperature state of the engine.

For example, when only one specific exhaust valve is driven to open and close, exhaust gas flows out only from one exhaust port connected to the exhaust valve. The temperature drop is small, and the temperature rise of the exhaust purification catalyst interposed downstream of the exhaust passage can be accelerated.

Further, in the case of an electromagnetically driven exhaust valve, the viscosity of the engine lubricating oil increases as the temperature becomes lower, the friction in driving the exhaust valve increases, the required current increases, and the power consumption increases. Therefore, only one exhaust valve is used. It is desirable to drive to reduce power consumption. However, if only one specific exhaust valve is opened and closed, the temperature rises due to the heat generated by the electromagnetic coil on the drive side, causing a temperature difference with the stop side. , The movement time from fully open to fully closed) (the drive side where the temperature rises is short), and when switching to double valve drive is performed later, there is an effect due to the characteristic difference between the two valves. So from this point,
It is desirable to alternately open and close the two exhaust valves one by one so that the heat generated from the electromagnetic coils of the two exhaust valves is equalized so that there is no difference between the characteristics of the two valves.

Further, in the system in which two exhaust valves are alternately opened and closed one by one, in a system in which only one specific exhaust valve is opened and closed, wear of the exhaust valve and the valve seat is not biased toward the driving side. it can.

Therefore, the priority of these points is determined on the basis of the temperature state of the engine, and the opening / closing drive system of the exhaust valve is switched in accordance with the priority, thereby selecting the optimal opening / closing drive system. it can.

According to a second aspect of the present invention, there is provided an engine having two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing for each cylinder. The switching is performed based on the conditions including the temperature state and the load.

According to the second aspect of the invention, the control method of the two exhaust valves is switched based on the condition including the temperature state and the load of the engine.

For example, when the engine load is equal to or higher than a predetermined value, it is difficult to satisfy the engine output performance with the single valve control system according to the temperature condition, so that a dual valve drive system is required.

Therefore, by switching the drive system for opening and closing the exhaust valve based on conditions including the temperature state and the load of the engine, a more optimal drive system for opening and closing can be selected.

Further, the invention according to claim 3 is based on FIG.
As shown in the figure, in an engine equipped with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing for each cylinder,
An engine temperature condition detecting means for detecting a temperature condition of the engine, and a control method switching means for switching a control method of the two exhaust valves based on a condition including the detected temperature condition of the engine. It is characterized by having done.

According to the third aspect of the present invention, the control method switching means switches the control method of the two exhaust valves based on the condition including the engine temperature state detected by the engine temperature state detecting means.

According to the present invention, an optimal opening / closing drive system is selected by switching the opening / closing drive system of the exhaust valve in accordance with the priority determined based on the temperature state of the engine. Can be.

Further, the invention according to claim 4 is the same as that shown in FIG.
As shown in the figure, in an engine equipped with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing for each cylinder,
Engine temperature state detecting means for detecting the temperature state of the engine, engine load detecting means for detecting the load of the engine, and the two exhaust valves based on conditions including the detected temperature state and load of the engine. And control system switching means for switching the control system.

According to the fourth aspect of the present invention, two control system switching units are used by the control system switching unit based on the condition including the engine temperature detected by the engine temperature detecting unit and the engine load detected by the engine load detecting unit. The control method of the exhaust valve is switched.

Thus, as in the case of the second aspect, by switching the open / close drive method of the exhaust valve based on the condition including the temperature state and the load of the engine, a more optimal open / close drive method can be selected. .

Further, the invention according to claim 5 is characterized in that when the engine is in a low load state, the above-mentioned 2
It is characterized in that the control method of the individual exhaust valves is switched.

According to the fifth aspect of the present invention, when the engine is in a low load state in which the output performance can be secured, the control method of the two exhaust valves is switched based on the engine temperature state. Can be satisfied.

The invention according to claim 6 is characterized in that, when the engine is in a very low temperature state, an alternate single-valve control system in which the two exhaust valves are alternately opened and closed one by one is selected. I do.

According to the sixth aspect of the invention, when the temperature is extremely low, the alternate single valve control system is selected, and the two exhaust valves are alternately opened and closed one by one. Here, the alternate one-valve control method is not limited to the method of switching the exhaust valve to be driven for each combustion stroke, but includes the method of switching every several combustion strokes or every predetermined time.

That is, as described above, when the temperature is low, the power consumption increases due to the increase in the friction due to the increase in the viscosity of the engine lubricating oil. Therefore, it is desirable to drive only one exhaust valve. At a very low temperature of about −20 ° C. or lower, in the fixed single valve control method in which only one specific exhaust valve is driven, the temperature of the electromagnetic coil on the driving side rapidly rises due to heat generation, and the distance between the electromagnetic coil on the stop side and Causes a large temperature difference, and when the operation is switched to the double valve driving, the influence of the characteristic difference between the two valves becomes large.

Therefore, by selecting an alternate single valve control system in which the two exhaust valves are alternately opened and closed one by one to evenly generate heat from the electromagnetic coils of the two exhaust valves, the characteristics of the two exhaust valves are improved. The difference can be eliminated, and the influence of the characteristic difference when switching to the double valve drive can be avoided.

The invention according to claim 7 is characterized in that, when the engine is in a low temperature state in which the temperature is higher than the cryogenic temperature and lower than the time when the warm-up is completed, only a specific one of the two exhaust valves is used. It is characterized in that a fixed one-valve control method for opening and closing is selected.

According to the seventh aspect of the present invention, when the engine is in a low temperature state in which the temperature is higher than the cryogenic temperature and lower than the time when the warm-up is completed, the fixed single valve control system is selected, and the two exhaust valves are controlled. Is driven to open and close.

That is, at low temperatures other than cryogenic temperatures, the viscosity of the engine lubricating oil is smaller than at cryogenic temperatures, the friction for driving the exhaust valves is small, and the characteristic difference between the two exhaust valves in the case of a fixed one-valve control system is obtained. The effect is small. On the other hand, the advantage of being able to improve the purification performance by promoting the increase in the temperature of the exhaust purification catalyst by reducing the decrease in the exhaust temperature by exhausting the exhaust only from the exhaust port connected to the exhaust valve on the driving side by the fixed one-valve control method. Is big.

Therefore, in such a low temperature state, by selecting a constant one-valve control method, it is possible to improve the exhaust gas purification performance at the time of a low temperature start or the like. Claim 8
The invention according to the invention is characterized in that, when the engine is in a high temperature state at the time of completion of warm-up, an alternate single-valve control system in which the two exhaust valves are alternately opened and closed one by one is selected.

According to the eighth aspect of the present invention, when the engine is in a high temperature state (and a low load state) upon completion of warm-up, an alternate single valve control system is selected, and two exhaust valves are alternately opened and closed one by one. Driven.

That is, when the exhaust flow rate is low and the load is low even after the completion of warm-up, the exhaust resistance at the time of exhaust valve outflow is small even in the single-valve control method, and power consumption is reduced by driving only the single valve. Therefore, it is preferable to select a one-valve control method because fuel efficiency can be improved. Further, since the frequency of use after the completion of the warm-up is large, if the fixed single-valve control method is selected, the exhaust valves and the valve seats are worn toward the drive side.

Therefore, the wear of the exhaust valve and the valve seat can be suppressed by selecting the alternate single valve control system. The invention according to claims 7 to 9 is based on the condition that the load is low, but it is not always necessary to be in the same low load state (region). The selection may be set so that a higher load region is selected as compared with the selection of the control method in another temperature region.

According to a ninth aspect of the present invention, when the load of the engine is higher than the low load state, the engine load is high
In a medium load state, a phase difference control method in which the two exhaust valves are opened / closed by shifting the opening timing is selected, and in a high load state, the two exhaust valves are simultaneously opened / closed. It is characterized in that a simultaneous control method is selected.

According to the ninth aspect of the present invention, in the middle load state, the phase difference control method is selected, and the two exhaust valves are opened and closed with the opening timing shifted.
The two-valve simultaneous control method is selected, and the two exhaust valves are simultaneously opened and closed.

That is, under a medium or high load state exceeding a predetermined value, in the single-valve control method, deterioration of fuel efficiency is increased due to a decrease in output due to pumping loss, or it becomes difficult to secure required output, so that both exhaust valves are driven. It is required to select a valve control method. However, in a simultaneous control method for both valves that opens and closes both exhaust valves simultaneously (at the same opening and closing timing),
The power required to open both exhaust valves at the same time against the in-cylinder pressure applied to the heads of both exhaust valves is large, so the power consumption increases, and the large control current increases the temperature of the electromagnetic coil. In some cases, thermal deterioration and durability may decrease.

Therefore, in a medium load state, by selecting a phase difference control system for opening and closing the two exhaust valves by shifting the opening timing, one of the exhaust valves is opened first to reduce the in-cylinder pressure. After opening the other exhaust valve, the total driving force and thus the power consumption are reduced, and the control current is reduced to suppress the temperature rise of the electromagnetic coil and to suppress the thermal deterioration and durability deterioration. By selecting the dual valve simultaneous control method only at the time of high load where the output is given the highest priority, the required output can be secured with a minimum pumping loss. Further, in the invention according to claim 10, when the load of the engine is higher than the low load state in a middle and high load state,
When the engine rotation speed is lower than the engine rotation speed that is set lower as the load is higher, a phase difference control method in which the two exhaust valves are opened / closed by shifting the opening timing is selected, Sometimes said 2
It is characterized in that a dual valve simultaneous control system for simultaneously opening and closing the exhaust valves is selected.

According to the tenth aspect, when the engine speed is lower than the engine speed set lower as the load increases, the phase difference control method is selected when the engine is running at a medium to high load state. The exhaust valves are opened / closed with their opening timings shifted, and when the engine speed is equal to or higher than the set engine speed, the dual valve simultaneous control method is selected and the two exhaust valves are simultaneously opened / closed.

That is, when the pumping loss at the time of exhaust valve outflow becomes larger than a predetermined value, it is necessary to switch to the dual valve simultaneous control system in preference to the phase difference control system, but the exhaust flow rate which determines the magnitude of the pumping loss is required. Affects the engine speed as well as the load. Therefore, even at a medium load, the exhaust flow rate is large and the pumping loss is large at high speed, so that the dual valve simultaneous control method is used. At a low load, the exhaust flow rate is small and the pumping loss is small, so the phase difference control method is used.

This makes it possible to more appropriately switch between the phase difference control method and the double valve simultaneous control method. The invention according to claim 11 is characterized in that the temperature state of the engine used for switching the exhaust valve control method is the temperature of the engine lubricating oil near the sliding portion of the movable part of the electromagnetically driven exhaust valve. I do.

According to the eleventh aspect, the temperature of the engine lubricating oil near the sliding portion of the movable portion of the electromagnetically driven exhaust valve is detected, and the control method of the exhaust valve is switched based on the lubricating oil temperature.

That is, the temperature of the lubricating oil in the vicinity of the sliding part of the movable part, for example, the movable part of the electromagnet, is a value that reflects the viscosity of the lubricating oil in this part, and therefore the friction state when the exhaust valve is operated, with high accuracy. Therefore, the control method of the exhaust valve can be more appropriately switched based on the temperature state (particularly, selection of the alternate single valve control method by detecting extremely low temperature).

Further, the invention according to claim 12 is characterized in that the temperature state of the engine used for switching the exhaust valve control system is an engine cooling water temperature.

According to the twelfth aspect, the control method of the exhaust valve is switched based on the detected engine coolant temperature. With this configuration, the engine temperature state can be detected simply and at low cost by using the water temperature sensor generally mounted for engine control.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 2 and 3 showing one embodiment, the engine 1 has two intake valves 2A, 2 for each cylinder.
2B and exhaust valves 3A and 3B, and corresponding intake ports 4A and 4B and exhaust ports 5A and 5B.
The intake valves 2A, 2B and the exhaust valves 3A, 3B are of an electromagnetic drive type, and are configured to be capable of independently controlling opening and closing.

On the other hand, a fuel injection valve 6 is mounted at one of the two intake ports 4A and 4B or at a branch point. An ignition plug 8 and an ignition coil 9 are mounted in the combustion chamber 7. Further, a crank angle sensor 10 that outputs a reference signal at a reference crank angle of each cylinder and outputs a unit angle signal for each minute crank angle is attached to the engine body,
The engine speed can be detected based on these signals. Further, an air flow meter 1 for detecting an intake air flow rate
1. A water temperature sensor 12 for detecting a cooling water temperature is mounted.

FIG. 4 shows a detailed configuration of the electromagnetically driven exhaust valve. The same applies to the electromagnetically driven intake valve. As shown in the figure, a cylinder head 51 of the engine is provided with a valve body 52 (only a single valve is shown in FIG. 2) which serves as an intake valve or an exhaust valve. A spring retainer 53 is fixed to an upper part of a valve shaft 52a extending above the valve body 52, and the spring retainer 53 and the cylinder head 5 are fixed.
A coil spring 54 for urging the valve body 52 toward the valve closing side is provided between the bottom wall of the recess 51a formed on the top wall.

A housing 55 is provided upright on the cylinder head 51. Inside the housing 55, a valve-closing-side electromagnet 56 and a valve-opening-side electromagnet 57 are fixed at positions vertically opposed to each other with a predetermined interval. Between the valve closing electromagnet 56 and the valve opening electromagnet 57,
A mover (armature) 58 of a soft magnetic material is provided, and a mover shaft member 58a connected to the top and bottom of the mover 58 is
By passing through a shaft guide member 59 inserted into the center of the valve-closing electromagnet 56 and the valve-opening electromagnet 57, it is slidably supported up and down.

The housing 55 of the mover shaft member 58a
A spring retainer 60 is provided at the upper end protruding from the top wall.
Is fixed, and a coil spring 62 for urging the mover 58 toward the valve opening side is provided between the inner surface of the top wall of the case 61 connected to the top wall of the housing 55 and the spring retainer 60. .

Before the engine 1 is started, the valve closing electromagnet 56 and the valve opening electromagnet 57 are alternately energized to resonate the mover 58, and when the amplitude becomes sufficiently large, the electromagnet moves to any of the electromagnets. After the initialization for attracting and holding the armature 58, when the valve is opened, the power supply to the upper valve-closing electromagnet 56 on which the armature 22 is attracted is stopped, and the armature 58 is biased by the coil spring 62. Move down,
By energizing the valve-opening electromagnet 57 from a position sufficiently close to the lower valve-opening electromagnet 57 to attract the mover 58, the valve body 52 is lifted to open the valve. When the valve is closed, the lower valve-opening electromagnet 5 that is attracting the mover 58 is closed.
7, the movable element 58 is moved upward by the urging force of the coil spring 54, and the valve closing electromagnet 56 is energized from a position sufficiently close to the upper valve closing electromagnet 56 to move. By sucking the child 58, the valve body 52 is seated on the seat portion and the valve is closed.

The shaft guide member 59 is provided with an oil temperature sensor 13 composed of a thermocouple or the like for detecting an engine lubricating oil temperature near a sliding portion of a movable element 58 which is a movable portion of the electromagnetically driven exhaust valve. Buried. However, the oil temperature sensor 13
Need not be provided for every exhaust valve, and may be provided for at least one exhaust valve of a specific cylinder.

Signals from the oil temperature sensor 13 and other various sensors are output to a control unit 14,
The control unit 14 performs a fuel injection control by outputting a fuel injection signal to the fuel injection valve 7 based on these detection signals, and outputs an ignition signal to the ignition coil 10 to perform ignition control. A valve drive signal is output to the valve drive device 2 to control the opening and closing of the intake valves 3A, 3B and the exhaust valves 4A, 4B, and to control the switching of the control method of the exhaust valves 4A, 4B based on the engine temperature state. .

Next, switching control of the exhaust valve control system according to the present invention will be described. FIG. 5 shows a flowchart of the switching control according to the first embodiment. Step 1
Then, it is determined whether or not the load of the engine is in a low load state. Specifically, a separately set basic fuel injection amount T
The determination is made based on whether or not p, the throttle valve opening, and the accelerator opening (required load) are equal to or less than the set values corresponding to the respective low loads.

If it is determined in step 1 that the engine is in a low load state, the process proceeds to step 2 where it is determined whether or not the engine temperature is in a very low temperature state. Specifically, it is determined whether or not the lubricating oil temperature detected by the oil temperature sensor 13 is equal to or lower than a predetermined extremely low temperature (for example, −20 ° C.).

If it is determined in step 2 that the engine is in the extremely low temperature state, the process proceeds to step 3, where the two exhaust valves 4A, 4
An alternate single-valve control method (see FIG. 8) in which B is alternately opened and closed one by one is selected. As a result, power consumption can be reduced, and the heat generated from the electromagnetic coils of the two exhaust valves is made uniform, so that the characteristic difference between the two exhaust valves is eliminated, and the influence of the characteristic difference when switching to the both valve driving can be avoided.

If it is determined in step 2 that the vehicle is not in the extremely low temperature state, the flow advances to step 4 to set whether or not the vehicle is in a low temperature state lower than the temperature at the time of completion of warm-up. Specifically, it is determined whether or not the lubricating oil temperature detected by the oil temperature sensor 63 is lower than the temperature at the time of completion of warm-up.

When it is determined in step 4 that the temperature is lower than the temperature at the time of completion of the warm-up, the process proceeds to step 5 and a specific one of the two exhaust valves 4A and 4B of each cylinder, for example, an exhaust valve A fixed one-valve control system (see FIG. 7) in which only the 4A or the exhaust valve 4B is driven to open and close is selected. As a result, power consumption can be reduced, exhaust gas flows out only from the exhaust port connected to the exhaust valve on the driving side, and a decrease in exhaust gas temperature is reduced, thereby increasing the temperature of the exhaust gas purification catalyst and improving the purification performance. .

If it is determined in step 4 that the temperature is higher than the temperature at the completion of warm-up, the process proceeds to step 3 in which the two exhaust valves 4A and 4B of each cylinder are alternately opened and closed one by one. Select the alternate single valve control method. As a result, power consumption can be reduced, wear of the two exhaust valves and the valve seat can be equalized after completion of frequently used warm-up, and wear on the drive side as in the case of a fixed single valve control system can be achieved. Can be prevented from being biased.

Next, if it is determined in step 1 that the engine is not in the low load state, the process proceeds to step 6 to determine whether the engine is in the medium load state or not, as described above, whether each parameter is equal to or less than the set value corresponding to the medium load. Determined by

If it is determined in step 6 that the engine is in the medium load state, the process proceeds to step 7 in which the two exhaust valves 4A and 4B of each cylinder are opened / closed with their opening timings shifted to open / close. Select 9). As a result, the in-cylinder pressure at the time of opening of the exhaust valve that is opened later is reduced, so that power consumption can be saved. In addition, the control current is reduced, and the temperature rise of the electromagnetic coil is suppressed while the heat deterioration and the durability are reduced. Can be suppressed.

If it is determined in step 6 that the engine is not in the medium load state, that is, it is determined that the engine is in the high load state, the flow advances to step 8 to simultaneously control the two exhaust valves 4A and 4B of each cylinder simultaneously. Select the method (see FIG. 10).
As a result, the required output under high load can be satisfied by minimizing the pumping loss.

Next, a second embodiment of the exhaust valve control system switching control will be described with reference to the flowchart of FIG. The switching control based on the engine temperature state in the low load state in steps 1 to 6 is the same as in the first embodiment.

If it is determined in step 1 that the engine is not under the low load, that is, the engine is in the middle or high load state, the process proceeds to step 11 in which the engine speed for the control system switching determination is determined in accordance with the load level obtained by each of the above parameters. Threshold value N0
Is set by a search from a map or the like. In particular,
The threshold value is set to the lower speed side as the load increases. For simplicity, two thresholds may be set in two stages of medium load and high load.

Then, the process proceeds to a step 12, wherein it is detected whether or not the current detected engine speed N is less than the threshold value N0 set in the step 11, and if it is determined that the engine speed N is less than the threshold value N0, the process proceeds to a step 13. By selecting the phase difference control method, the power consumption can be reduced, and the thermal deterioration and durability of the electromagnetic coil can be suppressed. That is, since the exhaust flow rate is relatively small and the output decrease due to the pumping loss can be relatively small, the above advantage is prioritized.

On the other hand, if it is determined in step 12 that the actual engine speed N is equal to or higher than the threshold value N0, the exhaust flow rate is large and the output is greatly reduced due to pumping loss. When it is determined that it is difficult to secure the output, the process proceeds to step 14, where the two-valve simultaneous control is selected to secure the required output.

In the middle and high load state, a threshold value is set based on the intake air flow rate substantially equal to the exhaust flow rate, and the detected intake air flow rate is compared with the threshold value to determine the phase difference control method and the simultaneous control method. May be switched.

In the embodiment described above, the exhaust valve control system is switched based on the lubricating oil temperature. However, the exhaust valve control system is simply based on the engine coolant temperature detected by the coolant temperature sensor. It is good also as a structure which switches a system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration and functions of the invention according to claims 3 and 4;

FIG. 2 is a system diagram of an engine including an electromagnetically driven exhaust valve control device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the vicinity of a combustion chamber of the engine.

FIG. 4 is a longitudinal sectional view of an electromagnetically driven exhaust valve.

FIG. 5 is a flowchart of a first embodiment of switching control of a control method of two electromagnetically driven exhaust valves according to the present invention.

FIG. 6 is a flowchart of a second embodiment of switching control of a control method of two electromagnetically driven exhaust valves according to the present invention.

FIG. 7 is a time chart showing the operating states of two exhaust valves and the operating states of intake valves in a fixed one-valve control system.

FIG. 8 is a time chart showing the operating states of two exhaust valves and the operating states of intake valves in the alternating single valve control system.

FIG. 9 is a time chart showing the operation states of two exhaust valves and the operation states of intake valves in the phase difference control method.

FIG. 10 is a time chart showing an operation state of two exhaust valves and an operation state of an intake valve in the dual valve simultaneous control method.

[Explanation of symbols]

 Reference Signs List 1 engine 3A, 3B electromagnetically driven exhaust valve 10 crank angle sensor 12 water temperature sensor 14 control unit

Continued on the front page F-term (reference) 3G092 AA05 AA11 CB02 DA02 DA07 DA11 DA14 DG02 DG09 EA08 EA11 EA12 EA13 FA00 FA15 FA25 FA36 FA38 FA42 GA01 GA02 GA14 HA01Z HA06Z HD01X HD02X HE03Z HE06Z HE08Z HF08Z 3H05 DBA DB26 DB32 DC02 DC17 DD09 EE48 FB02 KK17

Claims (12)

[Claims] 1. An engine provided with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing of each cylinder, wherein a control method of the two exhaust valves is determined based on a condition including a temperature state of the engine. A control device for an electromagnetically driven exhaust valve, characterized in that it is switched by switching. 2. An engine provided with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing for each cylinder, wherein the control method of the two exhaust valves is determined by a condition including an engine temperature state and a load. A control device for an electromagnetically driven exhaust valve, wherein the control is performed based on the following. 3. An engine provided with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing for each cylinder, an engine temperature state detecting means for detecting a temperature state of the engine; An electromagnetically driven exhaust valve control device, comprising: control method switching means for switching a control method of the two exhaust valves based on a condition including a temperature state. 4. An engine provided with two electromagnetically driven exhaust valves capable of arbitrarily variably controlling the opening / closing timing of each cylinder, an engine temperature state detecting means for detecting an engine temperature state, and detecting an engine load. An engine load detecting means, and a control method switching means for switching a control method of the two exhaust valves based on a condition including the detected temperature state and load of the engine. Control device for electromagnetically driven exhaust valve. 5. The control method according to claim 1, wherein the control method of the two exhaust valves is switched according to the engine temperature state when the engine is in a low load state.
The control device for an electromagnetically driven exhaust valve according to any one of the first to third aspects. 6. An electromagnetic valve according to claim 5, wherein when the engine is in a very low temperature state, an alternate single valve control system is selected in which the two exhaust valves are alternately opened and closed one by one. Control device for driven exhaust valve. 7. A fixed one-valve control system for opening and closing only one of the two exhaust valves when the engine is in a low temperature state, which is higher than cryogenic temperature and lower than the time of completion of warm-up. The control device for an electromagnetically driven exhaust valve according to claim 5, wherein the controller selects: 8. An alternate single-valve control system in which the two exhaust valves are alternately opened and closed one by one when the engine is in a high temperature state at the time of completion of warm-up.
A control device for an electromagnetically driven exhaust valve according to claim 6. 9. A medium-high load state in which the load of the engine is higher than the low-load state, and when the engine is in a medium-load state, a phase-difference control method of opening and closing the two exhaust valves by shifting their opening timings is selected. An electromagnetically driven exhaust system according to any one of claims 5 to 8, wherein in a high load state, a dual valve simultaneous control system for simultaneously opening and closing the two exhaust valves is selected. Valve control device. 10. In a medium-high load state where the load of the engine is higher than the low load state, when the engine rotation speed is lower than the engine rotation speed set lower as the load increases, the two exhaust valves are opened. 6. A phase difference control method for opening / closing and driving by shifting the two exhaust valves simultaneously is selected when the engine speed is equal to or higher than the set engine rotation speed. The control apparatus for an electromagnetically driven exhaust valve according to claim 8. 11. The temperature state of an engine used for switching the exhaust valve control method is a temperature of an engine lubricating oil near a sliding portion of a movable part of an electromagnetically driven exhaust valve. The control device for an electromagnetically driven exhaust valve according to claim 10. 12. The electromagnetically driven system according to claim 1, wherein the temperature state of the engine used for switching the exhaust valve control system is an engine cooling water temperature. Exhaust valve control device.