JP2002052940A - Control unit for variable engine mount - Google Patents

Abstract

(57) [Problem] To provide a negative-pressure variable engine mount that can appropriately suppress vibration transmission even when applied to an engine that switches the combustion mode during operation. An engine mount (20) for suspending and supporting an engine (E) whose combustion mode is switched between stratified combustion and homogeneous combustion during operation utilizes a differential pressure between an internal pressure of an intake passage (10) of the engine (E) and an atmospheric pressure. It is configured as a negative pressure type ACM whose vibration damping characteristics are variable based on air supply / discharge control. The ECU 14 changes the control mode of the air supply / exhaust control to the ACM 20 according to the combustion mode by switching the calculation map of the control command value in accordance with the switching of the combustion mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable engine mount control device for suspending and supporting an engine on a vehicle body and other supports, and having a variable damping characteristic.

[0002]

2. Description of the Related Art As an engine mount for suspending and supporting an engine, there is known a variable engine mount that varies the vibration damping characteristics of the engine mount according to the operating state of the engine and the running state of the vehicle. As such a variable engine mount, for example, as disclosed in Japanese Patent Application Laid-Open No. H10-148234, a negative pressure type variable engine mount that operates using negative pressure of intake air of an engine is known.

The negative pressure type variable engine mount has an air chamber provided therein and a negative pressure switching valve (VSV). The air chamber is partitioned by an elastic member, and its volume changes according to supply and discharge of air to and from the air chamber. VSV is in the intake passage of the engine,
The connection to the air chamber is switched between the downstream side of the throttle valve where the internal pressure becomes negative and the upstream side of the throttle valve where the internal pressure becomes atmospheric pressure. Thereby, the supply and discharge of air to and from the air chamber are switched, and the volume of the air chamber is changed. With the negative pressure variable engine mount,
By controlling the supply and exhaust of air using the negative pressure of intake air, the damping characteristics are made variable.

There are so-called semi-active and active systems as variable systems of the vibration damping characteristics of such a negative pressure type variable engine mount. In the semi-active variable engine mount, the static vibration transmission characteristics (spring constant, damping characteristics, etc.) of the engine mount are changed by adjusting the pressure in the air chamber, and the vibration damping characteristics are variable. Also, in the active type variable engine mount, the engine mount itself generates an output when switching the air supply and exhaust to the air chamber, and the output controls the vibration transmitted to the vehicle body in response to the input to the mount. It reduces the floor vibration of the vehicle and the sound level inside the vehicle. Then, by changing the generation mode of the mount output (the magnitude of the output, the generation cycle of the output, etc.), the vibration damping characteristic is made variable.

[0005] In the above publication, according to the switching of the operating state of the engine-related equipment, such as switching of the air conditioner on / off and switching of the shift range of the automatic transmission between the drive range and the neutral range. The control map for calculating the VSV control command value is switched. Therefore, the transmission of vibration between the engine and the vehicle body can be appropriately suppressed irrespective of a change in the intake negative pressure or a change in the generation mode of the vibration accompanying the switching of the operation state of the engine-related device.

On the other hand, there is known an engine such as an in-cylinder injection engine which selectively switches the combustion mode between homogeneous combustion and stratified combustion during operation. In the homogeneous combustion, combustion is performed in a state in which a mixture layer homogeneously dispersed in the entire cylinder is formed. Further, in the stratified combustion, combustion is performed in a state in which a flammable rich mixture is formed only around the ignition plug in the cylinder. Therefore, in the stratified combustion, the amount of intake air drawn into the cylinder at the same output (fuel injection amount) is relatively increased as compared with the homogeneous combustion, and combustion can be performed with a leaner air-fuel ratio.

[0007]

When a variable engine mount is applied as an engine mount for suspending and supporting an engine for switching the combustion mode, the following problems are inevitable.

[0008] When the combustion mode is switched, the vibration generation mode of the engine itself also changes greatly. For this reason, if the vibration suppression characteristics of the engine mount are kept constant before and after the switching of the combustion mode, appropriate vibration suppression cannot be achieved due to a change in the vibration generation mode.

[0009] Further, the above-mentioned negative pressure type variable engine mount has the following disadvantages. That is, since the air-fuel ratio is greatly different between stratified combustion and homogeneous combustion, when the combustion mode is switched, the amount of intake air taken into the cylinder also changes greatly, and the intake negative pressure also changes greatly. At this time, in the negative pressure type variable engine mount, whether the semi-active method or the active method described above operates using the intake negative pressure of the engine, such a large change in the intake negative pressure As a result, the vibration suppression characteristics of the engine mount change significantly. For this reason, when the combustion mode is switched, the vibration suppression characteristics of the engine mount and the vibration generation mode of the engine both greatly change, and the vibration transmission cannot be appropriately suppressed as it is.

[0010] In addition to the engine that switches the combustion mode between stratified combustion and homogeneous combustion, other than changing the compression ratio, the airflow state in the cylinder, the fuel injection pressure and the spray shape, or the number of operating cylinders, etc. An engine that switches a combustion mode during operation is known. Even with these engines,
If both the vibration suppression characteristics of the engine mount and the vibration generation mode of the engine greatly change when the combustion mode is switched, it is impossible to appropriately suppress the vibration transmission.

The present invention has been made in view of the above circumstances, and has as its object to provide a variable valve that can appropriately suppress vibration transmission even when applied to an engine that switches the combustion mode during operation. To provide an engine mount.

[0012]

The means for achieving the above object and the effects thereof will be described below. The invention according to claim 1 is a control device for a variable engine mount that suspends and supports an engine that selectively switches a combustion mode during operation and that varies its vibration damping characteristics.
A change means for changing the vibration suppression characteristics of the variable engine mount according to the combustion mode selected at that time is provided.

In the above configuration, the vibration suppression characteristics of the variable engine mount are changed according to the switching of the combustion mode.
Vibration transmission can be appropriately suppressed irrespective of a change in the vibration generation mode of the engine accompanying the switching of the combustion mode.

According to a second aspect of the present invention, the control device for a variable engine mount according to the first aspect is applied to an engine that switches a combustion mode between stratified combustion and homogeneous combustion.

During stratified charge combustion and during homogeneous charge combustion, the manner in which the engine generates vibrations and the state of intake negative pressure under the same operating conditions are significantly different. According to the above configuration, in a variable engine mount applied to an engine that switches the combustion mode between stratified combustion and homogeneous combustion, it is possible to set vibration damping characteristics suitable for each combustion state.

According to a third aspect of the present invention, in the control apparatus for a variable engine mount according to the first or second aspect, the changing means switches the vibration damping characteristic of the engine mount when switching the combustion mode. This is to gradually change the vibration damping characteristics from before to the vibration damping characteristics after switching.

In this configuration, when the control mode is changed,
Since the damping characteristics of the engine mount are gradually changed, even when the damping characteristics of the engine mount are greatly changed according to the change of the combustion mode, the damping characteristics of the variable engine mount are smoothly changed, It is possible to suppress the occurrence of a shock due to a rapid change in

The invention according to claim 4 is the invention according to claims 1 to 3.
In the control device for a variable engine mount according to any one of the above, a control map used for calculating a control command value related to the setting of the vibration suppression characteristics is provided for each of the switched combustion modes, and is selected at that time. The control mode is changed by the changing means by switching the control map according to the combustion mode.

In the above configuration, when the combustion mode is switched, a control map corresponding to the combustion mode is selected, and a control command value for setting the vibration suppression characteristics of the engine mount is calculated using the control map. become. If the control map is switched in this way, it is possible to easily and appropriately change the control mode according to the switching of the combustion mode.

The invention according to claim 5 provides the invention according to claims 1-4.
In the control device for a variable engine mount according to any one of the above, when the vibration suppression characteristics are changed, a control command value related to the setting of the vibration suppression characteristics is changed from a required value in a combustion mode before switching to a combustion mode after switching. The changing means is configured so as to change while gradually changing to the required value.

If the control command value is changed at the time of switching the combustion mode, a shock may occur due to a sudden change in the vibration suppression characteristics of the variable engine mount.
In this regard, in this configuration, when the combustion mode is switched, the control command value is gradually changed from a value required before the switching to a value required after the switching.
Therefore, when the combustion mode is switched, the vibration damping characteristics of the engine mount can be smoothly changed.

The invention according to claim 6 is the invention according to claims 1 to 5
The control apparatus for a variable engine mount according to any one of claims 1 to 3, wherein the variable engine mount is configured to control the supply and exhaust of air using an intake negative pressure of the engine, thereby making the vibration suppression characteristics variable. The changing means is configured to change a control mode of the air supply / discharge control according to a combustion mode selected at that time.

When the combustion mode is switched, the vibration generation mode of the engine changes, and the state of the intake negative pressure also changes greatly. For this reason, it becomes difficult to set the vibration damping characteristics of the negative pressure type variable engine mount controlled by the supply and exhaust of air using the intake negative pressure, and the vibration transmission is appropriately performed according to the change in the vibration generation mode of the engine. Is difficult to control. In this regard, in the above configuration, the control mode of the air supply / discharge control to the engine mount is changed according to the switching of the combustion mode. Thereby, an appropriate control mode corresponding to the engine vibration generation mode and the intake negative pressure state in each combustion mode is set in advance, and a control mode suitable for the combustion mode selected at that time is selectively used. Will be able to do it. Therefore, regardless of the change in the vibration generation mode of the engine and the change in the intake negative pressure accompanying the switching of the combustion mode, the transmission of the vibration can be appropriately suppressed.

According to a seventh aspect of the present invention, in the control device for a variable engine mount according to the sixth aspect, the change means is changed in the intake negative pressure state in the changed combustion mode when the control mode is changed. After changing the control command value once so that the vibration suppression characteristics required in the previous combustion mode are maintained, the control command value is changed to the required value in the changed combustion mode. It is.

In this configuration, when the combustion mode is switched, first, the control command value is changed so that the required vibration damping characteristic in the combustion mode before the switching is maintained in the intake negative pressure state in the switched combustion mode. You. As a result, the damping characteristics of the engine mount are maintained as they are, regardless of the change in the intake negative pressure due to the switching of the combustion mode. Then, thereafter, the control command value is changed to the required value in the combustion mode after switching. For this reason, even when the vibration suppression characteristics of the engine mount are significantly changed by switching the combustion mode, it is possible to smoothly switch to the desired vibration suppression characteristics without causing a shock or the like.

According to an eighth aspect of the present invention, in the control device for a variable engine mount according to the sixth aspect, when the control mode is changed, the combustion mode after the switching in the intake negative pressure state in the combustion mode before the switching. After changing the control command value once so as to obtain the required vibration damping characteristics, the change means is configured to further change the control command value to a required value in the changed combustion mode. is there.

A change in the intake negative pressure when the combustion mode is switched is accompanied by a response delay, and further delay occurs before the change in the intake negative pressure is reflected on the vibration damping characteristics of the engine mount. . For this reason, even if the control command value is changed to the required value after the switching together with the switching of the combustion mode, a desired vibration damping characteristic may not be obtained immediately due to a delay in the change of the intake negative pressure. Also, if the control command value is changed to the required value after switching based on the changed internal pressure before the intake negative pressure changes, the engine mount will temporarily show inappropriate vibration damping characteristics , Which may cause a shock or the like.

In this regard, in the above configuration, when the combustion mode is switched, first, the control is performed such that the required vibration damping characteristics in the combustion mode after the switching are obtained in the intake negative pressure state in the combustion mode before the switching. The command value is changed once. After that, the control command value is changed to the required value in the combustion mode after switching. For this reason, the vibration damping characteristic can be appropriately changed regardless of the response delay of the intake negative pressure.

According to a ninth aspect of the present invention, in the control device for a variable engine mount according to any one of the sixth to eighth aspects, switching between air supply and discharge to an air chamber provided inside the engine mount is performed. A valve is further provided, and the changing means changes a ratio of a period during which air is supplied and a period during which air is discharged by the switching valve in accordance with the switching of the combustion mode.

For example, as in the case of an active-type negative-pressure variable engine mount, the damping characteristic of the engine mount is set by adjusting the ratio between the period in which air is supplied and the period in which air is discharged by the switching valve. There is something. In such an engine mount, by changing the ratio in accordance with the switching of the combustion mode, it becomes possible to set vibration damping characteristics suitable for each combustion mode.

According to a tenth aspect of the present invention, in the control device for a variable engine mount according to the ninth aspect, a flow of air passing through the passage for controlling at least one of supply and discharge of air to the air chamber is provided. An adjusting means for adjusting the resistance is further provided, and the changing means also changes an adjusting manner of the air flow resistance by the adjusting means when the control mode is changed.

If the flow resistance of the air in the passage controlling the supply or exhaust of air to the air chamber is changed, the efficiency of air supply and exhaust to the air chamber changes, and the output characteristics of the engine mount change. Therefore, the degree of freedom in adjusting the output of the engine mount is increased, and it becomes easier to secure a desired ACM output. Therefore, irrespective of the change in the intake negative pressure due to the switching of the combustion mode, it is possible to secure an appropriate output according to the vibration generated by the engine in each combustion mode.

According to an eleventh aspect of the present invention, in the control device for a variable engine mount according to the ninth or tenth aspect, switching between supply and discharge of air to the air chamber is performed a plurality of times every explosion cycle of the engine. It is like that.

In this configuration, the supply and discharge of air to the air chamber are switched a plurality of times for each explosion cycle of the engine. As a result, the engine mount outputs a plurality of times each time an explosion occurs in the engine. Will occur. Therefore, depending on the output of the engine mount, not only the primary vibration of the engine explosion, but also the secondary explosion due to resonance,
Tertiary vibration and the like can be suitably damped.

The invention according to claim 12 provides the invention according to claim 11
In the variable engine mount control device described above, the changing means changes the number of times of switching between supply and discharge of the air when changing the control mode.

Due to the change in the vibration generation mode accompanying the switching of the combustion mode of the engine, among the primary and secondary vibrations of the explosion, the vibrations particularly required for damping may change.
For example, in the combustion mode before switching, it would have been better if the vibration was suppressed by narrowing down to only the primary vibration of the explosion. However, after the switching, the level of the secondary vibration of the explosion would be increased, and the secondary vibration would be specially controlled. May need to be implemented. In this regard, in this configuration, when the combustion mode of the engine is switched, the number of times of switching the air supply / discharge for each explosion cycle of the engine is changed, thereby changing the number of times the engine mount output is generated for each explosion cycle. Like that. Therefore, according to the change of the vibration generation mode accompanying the switching of the combustion mode, the vibration can be controlled in an appropriate mode.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment of a variable engine mount control device according to the present invention will be described in detail with reference to FIGS.

First, the configuration of a vehicle-mounted engine E to which the control device for a variable engine mount according to the present embodiment is applied will be described with reference to FIG. Engine E mounted on the vehicle
Is configured as an in-line four-cylinder engine having four cylinders. The engine E is configured as an in-cylinder injection engine that directly injects fuel into the cylinders, and the combustion mode changes between stratified combustion and homogeneous combustion according to the operating state of the engine E. It can be switched.

As shown in FIG. 1, the intake passage 10 of the engine E is provided with a throttle valve 11 for adjusting the amount of air taken into each cylinder of the engine E. Each cylinder is provided with an injector 12 for directly injecting fuel into the cylinder and an ignition plug 13 for igniting the injected fuel.

In such an engine E, various engine controls such as control of the intake air amount based on the opening degree control of the throttle valve 11, control of the amount and timing of fuel injection from the injector 12, control of ignition timing by the spark plug 13, and the like. Is performed by an electronic control unit (ECU) 14. The outputs of various sensors such as an air flow meter 15 for detecting the amount of air flowing through the intake passage 10 are input to the ECU 14. During operation, the ECU 14 switches the combustion mode between stratified combustion and homogeneous combustion in accordance with the operating state of the engine E, which is grasped based on the output results of the sensors.

In the homogeneous combustion, the fuel is injected from the injector 12 during the intake stroke to form a uniformly mixed gas layer in each cylinder. On the other hand, in the stratified charge combustion, fuel is injected from the injector 12 at a later stage of the compression stroke, so that a combustible dense mixture layer is formed only around the ignition plug 13. Therefore, if stratified combustion is performed, combustion at an ultra-lean air-fuel ratio becomes possible, and pumping loss and cooling loss are reduced, and the engine E
Fuel efficiency can be improved. Therefore, at the time of stratified combustion, the opening of the throttle valve 11 (throttle opening) is set to be relatively open as compared with the time of homogeneous combustion under the same operating conditions.

As shown in FIG. 1, the engine E constructed as described above is supported by a plurality of (two in the figure) negative-pressure variable engine mounts (negative-pressure ACM) 20. Suspended and supported by the vehicle body B.

The ACM 20 includes a cylindrical main body case 21 fixed to the vehicle body B and an upper cover 22 fixed to the engine E, as shown in FIG. The main body case 21 and the upper cover 22 are connected via an elastic member 23 made of an elastic material such as rubber, and are internally divided into two parts by an isolating member 24 also made of an elastic material such as rubber. Liquid chamber 25, 2
6 are formed. The interior of these two liquid chambers 25 and 26 is filled with a liquid such as oil, respectively.
The flow of the liquid between the two liquid chambers 25 and 26 is allowed through a small-diameter passage (not shown).

Further, a diaphragm 27 made of a sheet-like elastic member is provided on the upper surface of the separating member 24, and an air chamber 28 into which air is introduced is provided between the separating member 24 and the diaphragm 27. Is formed. Further, as shown in FIG. 1, the air chamber 28
Through a negative pressure switching valve (VSV) 30. The VSV 30 is further connected with a negative pressure passage 31 and an atmospheric pressure passage 32. The negative pressure passage 31 is connected to the negative pressure tank 3.
The intake passage 10 is connected to the downstream side of the throttle valve 11 via 1a. The atmospheric pressure passage 32 is connected to the intake passage 10 on the upstream side of the throttle valve 11. The air flowing upstream of the throttle valve 11 in the intake passage 10 is at atmospheric pressure, and the air flowing downstream thereof is throttled by the throttle valve 11 to have a negative pressure.

The VSV 30 is turned on / off in accordance with the presence or absence of a voltage applied to an electromagnetic solenoid provided inside the VSV 30 to connect one of the negative pressure passage 31 and the atmospheric pressure passage 32 to the supply / discharge passage 29. To communicate selectively. The applied voltage (VSV drive voltage) to such an electromagnetic solenoid is EC
It is controlled by U14.

When the negative pressure passage 31 communicates with the supply / discharge passage 29 by the VSV 30, the pressure in the air chamber 28 becomes equal to the internal pressure on the downstream side of the throttle valve 11 in the intake passage 10. , Air is discharged from the air chamber 28. Further, when the atmospheric pressure passage 32 is communicated, the air chamber 2 is maintained until the pressure in the air chamber 28 becomes equal to the internal pressure on the upstream side of the throttle valve 11.
Air is supplied into the inside 8. The volume of the air chamber 28 changes due to the supply and exhaust of air to and from the air chamber 28.

In the ACM 20, the static damping characteristic, that is, the ACM 20 is changed through the volume change of the air chamber 28.
The spring characteristics, damping characteristics, etc. can be made variable. For example, by maintaining a state in which the supply / discharge passage 29 and the negative pressure passage 31 are communicated by the VSV 30, the pressure of the air chamber 28 of the ACM 20 (air chamber pressure) decreases to the intake negative pressure, and the air chamber 28 Is minimal. At this time, the ACM 20 becomes the hardest (hard) as a cushioning material. The VSV 30 also controls the supply / discharge passage 2
9 and the atmospheric pressure passage 32 are maintained in communication with each other, whereby the pressure in the air chamber is increased to the atmospheric pressure, and the pressure in the air chamber 2 is increased.
The volume of 8 is maximum. At this time, the ACM 20 becomes the softest (softest) as a cushioning material. By performing the so-called semi-active ACM control that adjusts the static damping characteristics of the ACM 20, the body B and the vehicle B are controlled according to the change in the vibration generation mode accompanying the change in the operating state of the engine E and the like. Vibration transmission between the engines E can be appropriately suppressed.

When the engine E is operating at a high speed, the supply / discharge passage 29 and the atmospheric pressure passage 3 are controlled by the VSV 30.
2 is kept in a communication state, and the ACM 20 is the softest state as a cushioning material. In addition, when the engine E is operating at low speed, the VSV 30 keeps the supply / discharge passage 29 and the negative pressure passage 31 in communication with each other.
Is the hardest state as a cushioning material.

On the other hand, in the ACM 20, the ACM 20 itself can also achieve vibration suppression by generating an output in accordance with the vibration input to the ACM 20. That is, in the ACM 20, the volume of the air chamber 28 is repeatedly enlarged / reduced by periodically switching the presence / absence (on / off) of voltage application to the electromagnetic solenoid of the VSV 30, and an output is generated in accordance with the vibration input. , So-called active type ACM control can be performed. And such A
Generation mode of the output of the CM 20 (ACM output), that is, A
By adjusting the magnitude, generation cycle, generation timing, and the like of the CM output, the transmission of vibration between the vehicle body B and the engine E can be more effectively suppressed. And here, at the time of idling operation where the vibration of the engine E is more easily felt,
The drive control of the VSV 30 is performed to achieve vibration suppression in this manner.

Next, the VSV3 during such idling operation
The drive control of 0 will be described with reference to FIGS. FIG. 3 shows an example of a drive control mode of the VSV 30.

As shown in FIG. 3A, the ECU 14
The on / off switching of the VSV drive voltage is performed with one cycle of the ignition interval of the engine E (here, the ignition interval is 180 ° CA because the engine E is an in-line four cylinder). Here, by applying (turning on) a voltage of 12 V to the electromagnetic solenoid of the VSV 30, the supply / discharge passage 29 and the negative pressure passage 31 are communicated, and the application of the voltage is stopped (turned off). Thus, the supply / discharge passage 29 and the atmospheric pressure passage 32 communicate with each other. As a result, the pressure in the air chamber 28 (air chamber pressure)
3B changes at every ignition interval (explosion cycle) of the engine E as shown in FIG. 3B, and the ACM 20 generates an output accordingly.

The ECU 14 controls the VSV drive voltage using the voltage (VSV drive voltage) applied to the VSV 30 as a control command value using the control phase Δθ and the control duty Duty. The control phase Δθ is VS from the top dead center of each cylinder.
It shows the crank angle until the V drive voltage is turned on. The control duty Duty indicates the ratio of the phase (crank angle) φ at which the VSV drive voltage is turned on to the ignition interval of the engine E (here, the ignition interval is 180 ° CA because of a four-cylinder engine). ing. Therefore, the generation timing of the ACM output depends on the control phase Δθ, and the AC
The magnitude of the M output is adjusted accordingly. And ACM2 according to the magnitude and timing of the vibration input
The control phase Δθ and the control duty Duty are appropriately set so that 0 generates an output.

As described above, in the engine E, the combustion mode is switched between stratified combustion and homogeneous combustion in accordance with the operating conditions, and as a result, the intake negative pressure (intake passage) of the engine E during idle operation is changed. 10) changes according to the combustion mode. For example, during stratified charge combustion in which combustion at an ultra-lean air-fuel ratio is possible, a relatively large amount of air is generated in the engine E even during idling.
Inhaled. Therefore, during stratified charge combustion, the opening of the throttle valve 11 is set larger than during homogeneous charge combustion,
The internal pressure on the downstream side of the intake passage 10 becomes higher due to the smaller throttle. Therefore, the internal pressure downstream of the throttle valve 11 in the intake passage 10 during stratified combustion and the intake passage 10
Is smaller than the internal pressure on the upstream side of the throttle valve 11 at the time of homogeneous combustion. For this reason, as shown in FIG. 4, the relationship between the control duty Duty and the ACM output in each combustion is shown. Even if the control duty Duty is the same, the ACM output is smaller in the stratified combustion than in the homogeneous combustion. Would.

Further, when the combustion mode is switched, the vibration generation mode of the engine E also changes. In homogeneous combustion during idling operation, the combustion state is more stable, so that vibration generated by the engine E is smaller than in stratified combustion, and the required ACM output is correspondingly smaller.

As described above, the intake negative pressure state of the engine E differs between stratified charge combustion and homogeneous charge combustion.
20 changes its output characteristics. Further, since the vibration generation mode of the engine E is different, the required ACM output also changes. In the present embodiment, in order to perform appropriate vibration suppression irrespective of the change accompanying the switching of the combustion mode, the following AC
M control is performed.

A control map for calculating the control phase Δθ and the control duty Duty is stored in the ECU 14 in advance, and ACM control is performed based on the control map. In the present embodiment, two control maps, one for stratified combustion and one for homogeneous combustion, are prepared for each of the control phase Δθ and the control duty Duty. Each control map includes operating conditions of the engine E (eg, engine speed, fuel injection amount).
And the corresponding relationship between each control command value and each control command value. Then, these control maps are selectively used according to the combustion mode selected at that time. Details of the processing are as shown in FIG.

FIG. 5 shows a flowchart of a "control command value calculation routine" for calculating the control phase Δθ and the control duty. The series of processes shown in this flowchart is executed when the engine E is idling.
14 periodically and repeatedly executed.

When the process proceeds to this routine, the ECU 14 first determines in step 10 whether or not the combustion mode of the engine E at that time is stratified combustion. Then, in the case of stratified combustion (S10: Y), the target values of the control phase and the control duty, that is, the target control phase and the target control duty are calculated using the respective control maps for the stratified combustion (S20, S30). . If the combustion is homogeneous (S10: N), the target control phase and the target control duty are calculated using the respective control maps for homogeneous combustion (S40, S50).

Thus, between stratified combustion and homogeneous combustion,
The target value of the control command value for the control of the VSV 30, that is, the control of the supply and discharge of air to and from the air chamber 28 of the ACM 20 is calculated with reference to the different control maps.

If the control map for calculating the control command value is switched in accordance with the combustion mode, the output of the ACM 20 may change when the combustion mode is switched, causing a shock. Further, when the combustion mode is switched, the intake negative pressure changes accordingly, and the output characteristics of the ACM 20 change (see FIG. 4). In addition, there is a response delay due to the movement of air in the negative pressure passage 31 before such a change in the intake negative pressure is reflected on the output characteristics of the ACM 20. For this reason, if the control command value is changed simultaneously with the switching of the combustion mode, the ACM is temporarily stopped due to the response delay.
The output will be inappropriate and shock will still occur. In particular, when the combustion mode is switched between stratified combustion and homogeneous combustion, changes in the intake negative pressure and vibration generation mode are large, and the occurrence of the shock is difficult to ignore.

Therefore, in the present embodiment, the ECU 14 calculates the target value of each control command value through the processing of steps 10 to 50, and then executes the processing of step 60 and subsequent steps to execute the control duty of the control duty used for the actual control through the processing of step 60 and subsequent steps. The value (actual control duty Duty) is gradually changed. That is, if the target control duty is lower than the actual control duty Duty (S60: Y), the actual control duty Duty is reduced by the predetermined value a. a
The actual control duty value is gradually changed with respect to the change of the target control duty value by increasing the value of the actual control duty.

After performing the processing of this routine,
The CU 14 sets the actual control duty calculated here to be used for actual control of the VSV 30. In this embodiment, the control phase is not subjected to the gradual change process, and the target value calculated using the control map is set as it is.

As shown in FIG. 6, when the combustion mode is switched, the value of the actual control duty Duty is smoothly changed from the required value (target value) in the combustion mode before the switching to the required value after the switching. It will change. When the combustion mode of the engine E is switched from stratified combustion to homogeneous combustion, the value of the control duty Duty gradually decreases from the target value A in stratified combustion until the value becomes the target value B in homogeneous combustion. Will be done. When the combustion mode of the engine E is switched from the homogeneous combustion to the stratified combustion, the value of the control duty Duty is thereafter changed to the target value B in the homogeneous combustion until the value becomes the target value A in the stratified combustion.
Gradually increases.

For this reason, in this embodiment, the ACM output changes smoothly regardless of the change in the target value of the control duty Duty accompanying the switching of the combustion mode and the change in the output characteristics of the ACM 20 due to the change in the intake negative pressure. Become like As a result, it is possible to suppress vibration caused by a sudden change in the ACM output, and to achieve appropriate vibration suppression according to the combustion mode selected at that time.

By gradually changing the actual value of the control duty Duty when the target value changes, the following ACM control can be performed. That is, it is as follows.

As described above, in the present embodiment, ON / OFF of the active ACM control is switched according to the running conditions of the vehicle. That is, during the idling operation, an active ACM control that periodically generates an ACM output is performed, and a semi-active ACM control that does not generate an ACM output is performed otherwise. Even when the active ACM control is switched on and off, the operation of FIG.
As shown by a dotted line, the value of the control duty Duty is changed from “0” to a predetermined value (a target value of the control duty Duty after the start of the active control) C, or the predetermined value C
, The output mode of the ACM 20 may suddenly change and a shock may occur.

In this regard, in the present embodiment, as shown by the solid line in FIG. 7, even when the active type ACM control is switched on / off, the value of the control duty Duty is gradually changed, and the output mode of the ACM 20 is changed. Since the change is made smoothly, the occurrence of such a shock can be suppressed.

According to the present embodiment described above, the following effects can be obtained. (1) In the present embodiment, the control map used for calculating each control command value is switched according to the switching of the combustion mode between stratified combustion and homogeneous combustion, whereby the VSV 30 related to air supply / discharge control is controlled. The control mode is changed. Therefore, irrespective of the change of the intake negative pressure and the change of the vibration generation mode of the engine E accompanying the switching of the combustion mode between the stratified combustion and the homogeneous combustion, appropriate vibration damping characteristics are set and the vibration transmission is appropriately performed. Can be suppressed.

(2) In this embodiment, the engine E
A set of control maps showing a correlation between the operating state of the ACM 20 and a control command value (control phase Δθ, control duty Duty) of the VSV 30 related to air supply / discharge control to the ACM 20 is provided separately for each of the combustion modes that can be switched. Like that. Then, when the combustion mode of the engine E is switched, the control command value is changed according to the switched combustion mode by switching the set of control maps used for calculating each control command value. Therefore, the control command value can be easily and appropriately changed according to the switching of the combustion mode.

(3) In the present embodiment, when changing the target value of the control command value related to the supply / discharge control of the VSV 30 when the combustion mode is switched, the control duty Duty is switched from the target value in the combustion mode before the switching. The value is gradually changed to a target value in a later combustion mode. As a result, it is possible to prevent a sudden change in the ACM output when the control command value is changed when the combustion mode is switched, and to suppress the occurrence of a shock.

The embodiment described above can be modified as follows. In the above embodiment, when changing the target value of the control command value accompanying the switching of the combustion mode, only the value of the control duty Duty is gradually changed, but the value of the control phase Δθ is also changed in the combustion mode before the switching. May be gradually changed from the target value to the target value in the combustion mode after switching.

In the above embodiment, when the target value of the control command value is changed in accordance with the change of the combustion mode, the actual value of the control command value used for the actual control is gradually changed. Even without performing such a gradual change process, if the control command value of the VSV 30 is changed according to the switching of the combustion mode, the vibration generation mode of the engine E accompanying the switching of the combustion mode and the change of the intake negative pressure state thereof are changed. Regardless, AC
The vibration damping characteristics of M can be set appropriately.

Further, when the combustion mode is switched as in the above embodiment, the change of the air supply / exhaust control mode for the ACM is not limited to the switching of the combustion mode between the stratified combustion and the homogeneous combustion, and the compression ratio and the cylinder are changed. The present invention can also be applied to switching of the combustion mode by changing the airflow mode, the fuel injection pressure or the spray shape, or the number of operating cylinders. Even in such a case, the same effect as the above embodiment can be obtained.

Further, by adjusting the amount of air in the air chamber (the internal pressure of the air chamber), its static vibration damping characteristics (spring constant,
Semi-active AC with variable attenuation characteristics
Even in a negative pressure variable engine mount that performs M control,
By changing the air supply / discharge control mode in accordance with the switching of the combustion mode as in the above embodiment, the ACM can be performed regardless of the vibration generation mode of the engine E accompanying the switching of the combustion mode or the change in the intake negative pressure state. Can be set appropriately.

Also, such a semi-active type A
In the case of a negative pressure variable engine mount that performs CM control, the control command value is gradually changed from the target value before switching to the target value after switching when the control command value is changed due to switching of the combustion mode. This prevents a sudden change in the vibration damping characteristics of the engine mount and suppresses the occurrence of shock.

Further, such a semi-active type A
In a negative pressure variable engine mount that performs CM control,
For example, when the control command value is changed other than when the combustion mode is changed, such as when the control command value is changed due to a change in the running state of the vehicle, the value is gradually changed, so that the vibration suppression characteristics of the engine mount are improved. Can be prevented from abruptly changing, and the occurrence of shock can be suppressed.

Also, an electromagnetic variable engine mount that varies the damping characteristics according to the voltage applied to an electromagnetic solenoid disposed inside the engine mount, or a hydraulic pressure that varies the damping characteristics based on hydraulic control As for the variable engine mount of a type other than the negative pressure type such as the variable type engine mount, as in the above embodiment, if the control mode is changed according to the switching of the combustion mode,
Vibration can be appropriately suppressed irrespective of a change in the vibration generation mode of the engine E when the combustion mode is switched.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 8 and 9, focusing on differences from the first embodiment.

As described above, if the value of the control duty Duty is switched from the target value in the combustion mode before the switching to the target value in the combustion mode after the switching simultaneously with the switching of the combustion mode, the ACM output fluctuates temporarily. Shock may occur. Therefore, in the present embodiment, the ECU
14 changes the value of the control duty Duty in the following manner when switching the combustion mode,
The fluctuation of the M output is suppressed to suppress the occurrence of a shock.

In this embodiment, the ECU 14 sets the target control duty to the value a1 to obtain the ACM output of the required output D1 during homogeneous combustion, and sets the required output AC during stratified combustion.
It is assumed that the value a3 is set as the target control duty to obtain the M output. Therefore, the value of the control duty Duty can be switched between the target value a1 during homogeneous combustion and the target value a3 during stratified combustion according to the switching of the combustion mode.

In stratified charge combustion, compared to homogeneous charge combustion, AC
The differential pressure between the negative pressure applied to M20 (the internal pressure of the negative pressure passage 31) and the atmospheric pressure (the internal pressure of the atmospheric pressure passage 32) is reduced, and the ACM output is reduced even if the value of the control duty Duty is the same. In addition, the vibration generated by the engine E is greater during stratified combustion, and the required output of the ACM 20 is greater due to the vibration suppression (D1 <D2). Therefore, the target value a3 of the control duty Duty during stratified charge combustion is set to a value larger than the target value a1 during homogeneous charge combustion (a3> a1).

In this embodiment, when the combustion mode is switched, the ECU 14 first sets the A in the combustion mode before the switching in the negative pressure state in the combustion mode after the switching.
The value of the control duty Duty is changed so that the required output of the CM 20 is obtained. After that, the value of the control duty Duty is gradually changed from the value a2 to the target value after switching.

For example, in the case of switching from the homogeneous combustion to the stratified combustion, as shown by the arrow with the symbol (i) in FIG. 8, after the combustion mode is switched, first, the value of the control duty Duty is switched once. The target value a1 in the previous stratified combustion is changed to a value a2. The value a2 is a value of the control duty Duty set so that the required output D1 in the homogeneous combustion before the switching of the ACM output is obtained in the negative pressure state in the stratified combustion after the switching. Then, as shown by the arrow with the reference numeral (ii) in FIG. 8, the value of the control duty Duty is gradually changed from the value a2 to the target value a3 in the stratified combustion after switching.

On the other hand, in the case of switching from stratified combustion to homogeneous combustion, as shown by the arrow marked with the symbol (i) in FIG. 9, after the combustion mode is switched, first, the value of the control duty Duty is temporarily changed to: The target value b1 in the stratified combustion before the change is changed to the value b2. This value b2 is a value of the control duty Duty set so as to obtain the required output D2 in the stratified combustion before the switching in the negative pressure state in the homogeneous combustion after the switching. Then, as shown by the arrow with reference numeral (ii) in FIG. 9, the value of the control duty Duty is gradually changed from the value b2 to the target value b3 in the homogeneous combustion after switching.

As described above, when the value of the control duty Duty is changed at the time of switching the combustion mode, the value is simply changed linearly as in the first embodiment. The ACM output can be made to transition more smoothly, and the occurrence of a shock or the like can be suppressed more appropriately.

According to the embodiment described above, the following effects can be obtained in addition to the effects described in the above (1) and (2). (4) In the present embodiment, in the negative pressure state in the combustion mode before switching, the control duty D is adjusted so that the vibration suppression characteristics (ACM output) required in the combustion mode after switching are obtained.
After once changing the value of the duty, the value of the control duty Duty is further changed to the target value in the combustion mode after the switching. As a result, regardless of the change in the negative pressure state accompanying the switching of the combustion mode, the ACM output smoothly changes, and the occurrence of a shock or the like can be suppressed.

The mode of changing the value of the control duty Duty at the time of switching the combustion mode in the above embodiment is as follows.
Not only switching of the combustion mode between stratified combustion and homogeneous combustion, but also switching of the combustion mode by changing the compression ratio, the airflow mode in the cylinder, the fuel injection pressure or spray shape, or the number of operating cylinders Can also be applied. Even in such a case, the same effect as the above embodiment can be obtained.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 10 and 11, focusing on differences from the above embodiments.

FIG. 10 shows A during homogeneous combustion and stratified combustion.
FIG. 11 shows the relationship between the CM output and the control duty Duty.
Indicates the transition of the internal pressure of the negative pressure passage 31 and the transition of the ACM output when the combustion mode is switched.

In this embodiment, the ECU 14 sets the value of the control duty Duty to the target value d1 to obtain the required output D1 of the ACM 20 during homogeneous combustion, and sets the control duty Duty to obtain the required output D2 of the ACM 20 during stratified combustion. The value is set to the target value d3.

First, a case where the value of the control duty Duty is immediately changed from the target value in the combustion mode before the switching to the target value in the combustion mode after the switching simultaneously with the switching of the combustion mode will be described.

As described above, when the combustion mode is switched, the throttle opening is changed, and the negative pressure state in the intake passage 10 is changed. However, there may be a delay before the change in the negative pressure state is reflected on the output characteristics of the ACM 20 due to the time required for the movement of air in the intake passage 10 or the negative pressure passage 31.

Therefore, if the value of the control duty Duty is immediately changed to the target value in the post-switching combustion mode at the same time as the switching of the combustion mode, the internal pressure in the negative pressure passage 31 is still the same as before the switching. As shown by a broken line in FIG. 11, inappropriate ACM output may be temporarily generated.

For example, immediately after switching to stratified combustion,
Due to the delay, the state of the negative pressure (the internal pressure of the negative pressure passage 31) applied to the main force characteristic of the ACM 20 is a state in which the negative pressure state in the homogeneous combustion is still maintained. In such a case, if the value of the control duty Duty is changed to the target value a3 for stratified combustion at the same time as switching to stratified charge combustion, the ACM output temporarily exceeds the required output D2 for the original stratified charge combustion, and exceeds that. An excessive output D3 is generated.

The same applies to switching from stratified combustion to homogeneous combustion. That is, if the value of the control duty Duty is switched from the target value a3 during stratified combustion to the target value a1 during homogeneous combustion in a negative pressure state still in stratified combustion, the ACM output temporarily changes to homogeneous combustion. Is much lower than the required output D1.

As in the first embodiment, when the combustion mode is switched, the value of the control duty Duty is gradually changed by a predetermined value from the target value before the switching to the target value after the switching. The temporary increase and decrease of the ACM output as described above can be suppressed. However,
If the value of the control duty Duty is simply linearly changed in this manner, an inappropriate change in the ACM output may not be sufficiently suppressed depending on the change in the negative pressure applied to the ACM 20.

Therefore, in this embodiment, such ACM2
Regardless of the delay in the change of the negative pressure state that affects the output characteristic of 0, the control duty Duty is changed in the following manner in order to appropriately change the ACM output.

In this embodiment, as shown by the arrow with the symbol (i) in FIG. 10, after the combustion mode is switched, the value of the control duty Duty is first set to the target value in the homogeneous combustion before the switching. The value is changed from d1 to d2. This value d1 is the value of A in homogeneous combustion before switching.
This is a value of the control duty Duty set so as to obtain the required output D2 of the ACM 20 in the stratified combustion after switching in the negative pressure state applied to the CM 20. And then
The ECU 14 sets the value of the control duty Duty to the value d2, as indicated by the arrow denoted by reference numeral (ii) in FIG.
To gradually change to the target value d3 in the homogeneous combustion after switching.

In this embodiment described above, the above (1)
In addition to the effects described in (2) and (2), the following effects can be further obtained. (5) In this embodiment, when switching the combustion mode,
In the negative pressure state in the combustion mode before switching, the value of the control duty Duty is once changed so as to obtain the ACM output required in the combustion mode after switching, and then to the target value in the combustion mode after switching. Control duty Duty
Is further changed. Therefore, an appropriate ACM output can be obtained irrespective of a delay in the change of the negative pressure state.

The manner of changing the value of the control duty Duty at the time of switching the combustion mode in the above-described embodiment is not limited to switching of the combustion mode between stratified combustion and homogeneous combustion, but also includes the compression ratio and the airflow in the cylinder. The present invention can also be applied to switching of the combustion mode by changing the mode, the fuel injection pressure, the spray shape, or the number of operating cylinders. Even in such a case, the same effect as the above embodiment can be obtained.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. 12 to 14, focusing on differences from the above embodiments.

As described above, the ACM 20 has the engine E
By generating an output (ACM output) in accordance with the supply and exhaust of air to and from the air chamber 28 whose volume can be changed in synchronization with the explosion cycle of the vehicle, vibration transmission between the engine E and the vehicle body B is reduced. Like that. On the other hand, the vibrations generated in response to the explosion in the engine E include not only the primary vibration of the explosion synchronized with the explosion cycle, but also the secondary vibrations of a plurality of frequencies caused by the resonance accompanying the primary vibration of the explosion at the same time. . As shown in FIG. 3, if the VSV drive voltage is only turned on for a certain period for each explosion cycle of the engine E, the ACM
20 can only generate an output at a frequency synchronized with the explosion cycle of the engine E. Therefore, it is difficult to mask the vibration other than the primary vibration of the explosion, that is, to control the force transmitted to the vehicle body B in response to the input of the vibration to reduce the vehicle floor vibration and the sound level in the vehicle.

Therefore, in the present embodiment, by controlling the driving of the ACM 20 in the following manner, in addition to the primary vibration of the explosion, the secondary vibration of the explosion having twice the frequency thereof is masked. .

FIG. 12A shows the manner of applying the VSV drive voltage required for generating the ACM output for masking the primary vibration of the engine E, and FIG. 12B shows the manner of masking the secondary vibration of the explosion. Of the VSV drive voltage required for generating the ACM output of FIG. in this way,
The mask of the explosion secondary vibration has the VS at a period (90 ° CA) that is half of each explosion period (180 ° CA) of the engine E.
It is necessary to apply a V drive voltage. In addition, since the amplitude of the secondary vibration of the explosion is smaller than that of the primary vibration of the explosion, the application period of the voltage in each cycle becomes shorter than the application period of the voltage in each cycle applied to the mask of the primary vibration.

In this embodiment, the VSV drive voltage is applied in such a manner that they are superimposed as shown in FIG. Thereby, as shown in FIG. 3D, the internal pressure of the air chamber 28 rises and falls twice every explosion cycle. As a result, the ACM 20 generates an output twice each in each explosion cycle, so that both the primary vibration and the secondary vibration of the engine E can be suitably masked.

Such a method can be similarly applied to masking of a plurality of vibrations having different frequencies besides the above example. That is, A for masking each vibration
If the VSV drive voltage is applied with a waveform formed by superimposing the respective VSV drive voltage waveforms required for generating the CM output, a plurality of vibrations having different frequencies can be suitably masked.

As described above, the manner of generation of the vibration of the engine E changes by switching the combustion mode. Therefore, even when the ACM control as described above is performed,
It is preferable to change the application mode of the VSV drive voltage according to the combustion mode selected at that time. An example is given below.

In this example, as shown in FIG.
At the time of stratified combustion, the level (magnitude of vibration) of the primary vibration and the secondary vibration of the explosion is high, both exceeding the permissible limit, and a mask is required for both the vibrations. On the other hand, at the time of homogeneous combustion, as shown in FIG. 3B, at the time of homogeneous combustion, the level of the secondary vibration of the explosion falls below the permissible limit, and a mask using only the primary vibration of the explosion is sufficient.

In such a case, at the time of stratified combustion, FIG.
2 (d), ie, 2 for each explosion cycle
The VSV drive voltage is applied such that the voltage rises and falls every time. Further, at the time of homogeneous combustion, the VSV drive voltage is applied in such a manner as shown in FIG. 3A, that is, such that the voltage rises and falls only once in each explosion cycle. Thus, FIG.
As shown in the figure, by changing the number of times the VSV drive voltage rises and falls for each combustion mode for each explosion cycle, that is, the number of times air is supplied to and discharged from the air chamber 28 of the ACM 20, vibration at a desired frequency in each combustion mode is performed. Can be properly masked.

According to this embodiment described above, the following effects can be obtained in addition to the effects described in the above (1) and (2). (6) In the present embodiment, the supply and discharge of air to and from the air chamber 28 of the ACM 20 are performed a plurality of times in each explosion cycle. As a result, the ACM 20 generates an output a plurality of times in each explosion cycle, so that, in addition to the explosion primary vibration generated in synchronization with the explosion cycle, vibrations of different frequencies such as the explosion secondary vibration can be suitably masked. become.

(7) In the present embodiment, a signal waveform of the VSV drive voltage is formed by synthesizing a plurality of waveforms having different voltage rising / falling periods. This makes it possible to appropriately mask a plurality of vibrations having different frequencies.

(8) In this embodiment, the number of times air is supplied to and discharged from the air chamber 28 of the ACM 20 in each explosion cycle is changed according to the switching of the combustion mode. This makes it possible to appropriately mask the vibration at the desired frequency as required for each combustion mode.

The above embodiment can be modified as follows. In the above embodiment, A is changed according to the switching of the combustion mode.
Although the number of times of supplying and discharging air to and from the air chamber 28 of the CM 20 is changed, such a change may not be performed as long as the required frequency of the mask is the same in each combustion mode.

The ACM control in the embodiment as described above is not limited to the engine E for switching the combustion mode between stratified combustion and homogeneous combustion, but also includes the compression ratio, the airflow mode in the cylinder, and the fuel injection. The present invention can also be applied to an engine that switches the combustion mode by changing the pressure, the spray shape, or the number of operating cylinders. And even in that case, the same effect as the above embodiment can be obtained.

The same ACM as in the above embodiment is used in an engine that does not switch the combustion mode.
Control, that is, control for supplying and discharging air to and from the air chamber 28 of the ACM 20 according to a signal waveform formed by combining a plurality of waveforms having different voltage rising and falling cycles can be applied. Also in this case, a plurality of vibrations having different frequencies can be appropriately masked together.

ACM based on, for example, control of voltage application to an electromagnetic solenoid provided in an engine mount.
The same applies to the variable engine mounts other than the negative-pressure variable engine mount, such as an electromagnetic variable engine mount that generates an output or a hydraulic variable engine mount that generates an ACM output based on oil supply / discharge control, as in the above embodiment. In addition, the ACM output can be controlled in accordance with a signal waveform formed by combining a plurality of waveforms having different voltage rising / falling periods. Also in this case, a plurality of vibrations having different frequencies can be appropriately masked together.

(Fifth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. 15 to 17, focusing on differences from the above embodiments.

The internal pressure (intake negative pressure) of the intake passage 10 of the engine E changes in accordance with the switching of the combustion mode, and the output characteristics of the ACM 20 operated based on the differential pressure between the intake negative pressure and the atmospheric pressure change. . This is due to the change in intake negative pressure.
This is due to the fact that the efficiency of air supply and exhaust to and from the air chamber 28 of the ACM 20 changes. For example, the lower the intake negative pressure and the greater the differential pressure from the atmospheric pressure, the more the air supply and exhaust efficiency with respect to the air chamber 28 increases. For this reason, if the value of the control duty Duty corresponding to the period of discharging air from the air chamber 28 is the same, a larger ACM output is generated during homogeneous combustion in which the intake negative pressure is lower than in stratified combustion. Become like

On the other hand, the vibration generated by the engine E is smaller during the homogeneous combustion, and the ACM2 required for the vibration mask is smaller.
The required output of 0 also becomes smaller than that in the stratified combustion. For this reason, at the time of homogeneous combustion, although the vibration generated by the engine E is small and the required output of the ACM 20 is also small, the intake negative pressure is lower and the air supply / discharge efficiency is increased. On the other hand, at the time of stratified combustion, the vibration generated by the engine E is large and the required output of the ACM 20 is large, but the intake negative pressure becomes higher than that at the time of homogeneous combustion, and the air supply / discharge efficiency decreases. I will. For this reason, it is difficult to secure the required output of the ACM 20 in each combustion mode.

For example, in the ACM 20 set in accordance with the stratified combustion in which the intake negative pressure is higher and the vibration is larger, the desired small pressure is obtained in the homogeneous combustion in which the intake negative pressure is lower and the vibration of the engine E is smaller. ACM output may not be properly generated. In other words, the output characteristic is set in accordance with the stratified combustion.
In the CM20, during homogeneous combustion, the settable range of the ACM output shifts to the high output side in response to the decrease in the intake negative pressure, so that the required output at that time falls below the lower limit of the settable range. There is. The same applies to the reverse, and the ACM set for homogeneous combustion
In the case of No. 20, the large ACM output required during homogeneous combustion may not be able to be generated properly.

On the other hand, as described above, the change in the output characteristics of the ACM 20 due to the switching of the combustion mode is caused by the change in the air supply / exhaust efficiency with respect to the air chamber 28 due to the change in the intake negative pressure when the combustion mode is switched. Is due. Accordingly, at least one of the supply / discharge passage 29, the negative pressure passage 31, and the atmospheric pressure passage 32 is provided with a throttle for increasing the flow resistance of the air passing therethrough. Is provided, and if the amount of air flowing through the passage is restricted, the air supply / discharge efficiency is reduced. Thus, the output setting range of the ACM 20 can be shifted to the low output side. Therefore, if the air flow rate is limited only in the homogeneous combustion where the ACM output tends to be excessive, the AC set in the stratified combustion as described above is set.
With M20, an appropriate ACM output can be obtained even during homogeneous combustion.

In this embodiment, as shown in FIG. 15, the flow resistance of the air flowing through the negative pressure passage 31 between the negative pressure tank 31a of the negative pressure passage 31 and the VSV 30 can be adjusted. An air regulating valve 40 is provided. FIG. 16 shows a cross-sectional structure of the air adjustment valve 40.

As shown in FIG. 16, the air regulating valve 4
The inside of 0 is defined by two air chambers 41 and 42. These air chambers 41 and 42 are respectively connected to the negative pressure tank 31a side of the negative pressure passage 31 and the VSV 30 side. And these two air chambers 41 and 42 have two openings 43,
They are communicated with each other by 44.

The air adjusting valve 40 is provided with an electromagnetic valve having a valve body 45 and an electromagnetic solenoid 46. Then, the valve element 45 is driven in accordance with the on / off switching of the voltage application to the electromagnetic solenoid 46 to close / open one of the two openings (44). The on / off switching of the voltage application to the electromagnetic solenoid 46 is controlled by the ECU 14.

When the opening 44 is opened by the valve body 45 of the electromagnetic valve, air can flow between the air chambers 41 and 42 through both the openings 43 and 44. On the other hand, the opening 44 is provided by the valve body 45 of the electromagnetic valve.
Is closed, air can flow between the two air chambers 41 and 42 only through the opening 43. For this reason,
By closing / opening the opening 44 by the valve body 45 of the electromagnetic valve, the area of the air flow path between the air chambers 41 and 42 is changed, and the flow resistance of the air flowing through the air adjustment valve 40 is changed. become.

In the present embodiment, the ECU 44 closes the opening 44 during homogeneous combustion to limit the amount of air flowing through the air adjustment valve 40. During stratified combustion, the opening 44 is opened to release the restriction on the amount of air flowing through the air adjustment valve 40. For this reason, at the time of the homogeneous combustion in which the intake negative pressure becomes lower and the exhaust efficiency of the air from the air chamber 28 of the ACM 20 is originally high, the exhaust of the air is restricted.

FIG. 17 shows the ACM in this embodiment.
20 shows the relationship between the output of the control signal 20 and the control duty Duty.
In the figure, the above relationship during stratified combustion is indicated by a dashed line. Incidentally, at the time of stratified combustion, the above-mentioned air discharge restriction by the air adjustment valve 40 is not implemented as described above. Therefore, the air supply / discharge efficiency is sufficiently ensured, and the required output F of the ACM 20 at that time can be appropriately generated.

On the other hand, during the homogeneous combustion, as shown by the broken line in the figure, when the above-described air discharge restriction by the air adjustment valve 40 is not performed, the air discharge efficiency from the air chamber 28 of the ACM 20 is high. , ACM20 are on the high output side. Therefore, in the example shown in this figure, the required output G of the ACM 20 at the time of homogeneous combustion is below the lower limit of the output adjustment range.

Here, if the discharge of air from the air chamber 28 is restricted by the air control valve 40, the discharge efficiency of air is reduced, and as shown by the solid line in FIG. Move to As a result, the required output G of the ACM 20 at that time can be appropriately generated.

According to the present embodiment described above, the following effects can be obtained in addition to the effects described in the above (1) and (2). (9) In the present embodiment, the negative pressure passage 31 for discharging air from the air chamber 28 of the ACM 20 is provided with an air adjustment valve 40 for adjusting the flow resistance of the air flowing through the passage 31. . Then, in accordance with the switching of the combustion mode, the air regulating valve 40 causes the negative pressure passage 31 to move.
The flow resistance of the air flowing therethrough is changed.
This makes it possible to adjust the ACM output by adjusting the air supply / exhaust efficiency of the ACM 20 with respect to the air chamber 28, thereby facilitating securing a desired ACM output.
Therefore, irrespective of the change in the intake negative pressure due to the switching of the combustion mode, it is possible to secure an appropriate ACM output according to the vibration generated by the engine E in each combustion mode.

The above embodiment can be modified as follows. In the above embodiment, the air adjustment valve 40 is provided in the negative pressure passage 31 for discharging air from the air chamber 28 of the ACM 20. However, the air adjustment valve 40 is connected to the supply / discharge passage 29 and the atmospheric pressure passage 32. Even with the configuration provided, the supply and discharge efficiency of air to and from the air chamber 28 can be similarly adjusted. Therefore, also in this case, the same effect as the above embodiment can be obtained.

The configuration of the air adjusting valve 40 is not limited to the above-described embodiment, and may be arbitrarily changed. The point is that any device having a function of adjusting the flow resistance of air in the passage provided with the air passage may be used, for example, by adjusting the length of the passage to adjust the flow resistance of air. The same effect as that of the air adjustment valve 40 can be obtained.

The configuration similar to that of the above embodiment is not limited to the engine E for switching the combustion mode between stratified combustion and homogeneous combustion, but also includes the compression ratio, the airflow state in the cylinder, the fuel injection pressure and the spray pressure. The present invention can also be applied to an engine that switches the combustion mode by changing the shape or the number of operating cylinders. And even in that case, the same effect as the above embodiment can be obtained.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described with reference to FIGS.

As described above, in the ACM 20, the VSV3
By turning on / off the voltage application to 0, the internal pressure of the air chamber 28 is maintained at the intake negative pressure or the atmospheric pressure, and the static damping characteristics (spring constant, damping characteristics, etc.) of the ACM 20 are made variable. The so-called semi-active ACM control is performed. Even in such a static change of the vibration damping characteristics, the voltage applied to the VSV 30 (the VSV driving voltage) is gradually changed, so that a sudden change in the vibration damping characteristics can be prevented and the occurrence of a shock can be suppressed. . Such a gradual change of the VSV drive voltage can be performed by software processing by the ECU 14, but the VSV
It can also be realized by a hardware configuration of an electric circuit related to the driving of 30.

FIG. 18 shows an electrical configuration related to drive control of the VSV 30 in the control device for the variable engine mount of the present embodiment. The voltage (VSV drive voltage) applied to the electromagnetic solenoid of the VSV 30 is VSV
It is output by the drive circuit 100. The VSV drive circuit 100 outputs such a VSV drive voltage based on a command signal transmitted by the ECU 14. More specifically, the VSV drive circuit 100 outputs a voltage Hi (for example, 12 V) to the electromagnetic solenoid of the VSV 30 when an ON command is issued from the ECU 14,
, A voltage Lo (for example, 0 V) is output to the electromagnetic solenoid of the VSV 30.

In this embodiment, as shown in FIG. 18, the VSV 30 and the VSV drive circuit 100 are electrically connected via a capacitor 101. Then, by the action of the capacitor 101, the voltage input to the electromagnetic solenoid of the VSV 30 is gradually changed when switching between the voltage Hi and the voltage Lo.

FIG. 19 shows an example of such a control mode of the present embodiment. As shown in FIG.
When the command signal transmitted by the ECU 14 is switched from ON to OFF in 1, the VSV drive circuit 100 immediately changes the output voltage of the VSV 30 to the electromagnetic solenoid from the voltage Hi to the voltage Lo, as shown in FIG. Switch. On the other hand, the voltage input to the electromagnetic solenoid of the VSV 30 is, as shown in FIG.
01 causes the voltage Hi to gradually change to the voltage Lo. As shown in the figure, when the command signal is switched from off to on, the VSV 30
Input voltage to the electromagnetic solenoid from the voltage Lo to the voltage H
It gradually changes to i.

According to the above-described embodiment, the following effects can be obtained. (10) In the present embodiment, the VSV drive circuit 100 and the VSV
The V30 electromagnetic solenoid is electrically connected via a capacitor 101. Therefore, with an extremely simple configuration, it is possible to prevent a sudden change in the vibration damping characteristics of the ACM 20 and suppress the occurrence of a shock.

In the configuration in which the capacitor is used to suppress a sudden change in the damping characteristic of the ACM, the damping characteristic is made variable in accordance with the adjustment of the voltage applied to the electromagnetic solenoid provided in the ACM. The same can be applied to an electromagnetic ACM. In this case, a capacitor is interposed between the electromagnetic solenoid in the ACM and a drive circuit that outputs a voltage applied to the electromagnetic solenoid, thereby preventing a sudden change in the vibration control characteristics of the ACM and preventing the occurrence of a shock. Can be suppressed.

Next, the technical ideas grasped from the embodiments described above will be listed below. (A) In a variable engine mount control device that varies the vibration suppression characteristics of an engine mount that suspends and supports an engine, when a vibration suppression characteristic of the engine mount is changed, a value of a control command value related to control of the vibration suppression characteristics A variable engine mount control device that gradually changes the target value from the target value before the change to the target value after the change. According to this configuration, a sudden change in the vibration damping characteristics of the engine mount can be prevented, and the occurrence of a shock can be suppressed.

(B) In the variable engine mount control device which supplies and discharges air to and from the air chamber by utilizing the negative pressure of the intake air of the engine to increase or decrease the volume of the air chamber and generate an output, Adjusting means for adjusting the flow resistance of air flowing through a passage which controls at least one of supply and discharge of air to the air chamber, and air adjusting means for adjusting the air intake negative pressure of the engine in accordance with a change in the intake negative pressure of the engine. A control device for a variable engine mount, comprising: changing means for changing a flow resistance. According to this configuration, the degree of freedom in adjusting the output of the engine mount is increased, and it becomes easier to secure a desired ACM output.
Therefore, irrespective of the change in the intake negative pressure due to the switching of the combustion mode, it is possible to secure an appropriate output according to the vibration generated by the engine in each combustion mode.

(C) An air chamber surrounded by an elastic member is provided, and air is supplied to and exhausted from the air chamber using negative pressure of the intake air of the engine to expand or reduce the volume of the air chamber to generate an output. A control device for a variable engine mount, wherein air is supplied to and discharged from the air chamber a plurality of times in each explosion cycle of the engine. According to this configuration, the engine mount generates an output a plurality of times for each explosion cycle of the engine, and in addition to the explosion primary vibration generated in synchronization with the explosion cycle, vibration of a different frequency such as the explosion secondary vibration is generated. In addition, masking can be suitably performed.

(D) In a control device for a variable engine mount for varying the vibration damping characteristics of an engine mount for suspending and supporting an engine, a control signal for generating the vibration damping output of the engine mount is transmitted to a plurality of waveforms having different periods. A control device for a variable engine mount, wherein the control device is formed by synthesizing. According to this configuration, it becomes possible to appropriately mask a plurality of vibrations having different frequencies.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall structure of a first embodiment of the present invention.

FIG. 2 is a sectional view showing the sectional structure of the ACM according to the first embodiment;

FIG. 3 is a time chart showing an example of an ACM control mode of the embodiment.

FIG. 4 is a schematic diagram showing output characteristics of an ACM.

FIG. 5 is a flowchart showing a procedure for calculating a control command value according to the embodiment;

FIG. 6 is a time chart showing an example of a control mode of the embodiment.

FIG. 7 is a time chart showing an example of a control mode of the embodiment.

FIG. 8 is a schematic diagram showing both output characteristics of an ACM and an example of a mode of changing the control duty when switching the combustion mode in the second embodiment of the present invention.

FIG. 9 is a schematic diagram showing both the output characteristics of the ACM and an example of how the control duty is changed when the combustion mode is switched in the second embodiment.

FIG. 10 is a schematic diagram showing both output characteristics of an ACM and an example of a mode of changing a control duty when switching a combustion mode in a third embodiment of the present invention.

FIG. 11 is a time chart showing an example of a control mode of the embodiment.

FIG. 12 is a time chart showing an example of a control mode of the fourth embodiment of the present invention.

FIG. 13 is a schematic diagram showing a relationship between a vibration level and a frequency in each combustion mode.

FIG. 14 is a time chart illustrating a control mode example of the fourth embodiment.

FIG. 15 is a schematic diagram schematically showing the configuration of a fifth embodiment of the present invention.

FIG. 16 is a cross-sectional view showing a cross-sectional structure of the air adjustment valve according to the same embodiment.

FIG. 17 is an exemplary diagram showing output characteristics of the ACM according to the embodiment;

FIG. 18 is a schematic view schematically showing the entire configuration of a sixth embodiment of the present invention.

FIG. 19 is a time chart showing an example of a control mode of the embodiment.

[Explanation of symbols]

E: engine, B: vehicle body, 10: intake passage, 11: throttle valve, 12: injector, 14: electromagnetic control device (ECU: changing means), 20: negative-pressure variable engine mount, 28: air chamber, 29: supply Exhaust passage, 30 ... Negative pressure switching valve (VSV: switching valve), 31 ... Negative pressure passage, 32 ...
Atmospheric pressure passage, 40 ... air adjusting valve (air adjusting means),
100: VSV drive circuit, 101: capacitor.

Claims (12)

[Claims] 1. A control device for a variable engine mount for suspending and supporting an engine for selectively switching a combustion mode during operation and varying a vibration damping characteristic of the engine. A control device for a variable engine mount, comprising: a change unit for changing a vibration damping characteristic of the engine mount. 2. The control system for a variable engine mount according to claim 1, wherein said engine switches a combustion mode between stratified combustion and homogeneous combustion. 3. The switching means according to claim 1, wherein, when the combustion mode is switched, the vibration damping characteristic of the engine mount is gradually changed from the vibration damping characteristic before the switching to the vibration damping characteristic after the switching. Or the control device for a variable engine mount according to 2. 4. The control device for a variable engine mount according to claim 1, wherein a control map used for calculating a control command value for setting the vibration damping characteristic is changed for each of the switched combustion modes. Wherein the control mode is changed by the changing means by switching the control map according to the combustion mode selected at that time. 5. A method according to claim 1, wherein said changing means changes a control command value for setting said vibration damping characteristic from a required value in said combustion mode before switching to a required value in said combustion mode after switching. The control device for a variable engine mount according to any one of claims 1 to 4, wherein the control device changes while gradually changing the position of the variable engine mount. 6. The variable engine mount according to claim 1, wherein said variable engine mount is a negative pressure type variable engine mount that varies its vibration damping characteristics by controlling air supply and exhaust using an intake negative pressure of said engine. The control device for a variable engine mount according to any one of claims 1 to 5, wherein a control mode of the air supply / discharge control is changed according to a combustion mode selected at that time. 7. The control command, when the control mode is changed, such that the vibration control characteristic required in the combustion mode before switching is maintained in the intake negative pressure state in the combustion mode after switching. 7. The control device for a variable engine mount according to claim 6, wherein after the value is changed once, the control command value is further changed to a required value in the combustion mode after the switching. 8. The control command value, when changing the control mode, such that vibration control characteristics required in a combustion mode after switching in an intake negative pressure state in a combustion mode before switching are obtained. 7. The control device for a variable engine mount according to claim 6, wherein the control command value is further changed to a required value in the combustion mode after the switching after the change of the control command. 9. The control device for a variable engine mount according to claim 6, further comprising: a switching valve that switches between supply and discharge of air to an air chamber provided inside the engine mount. The control device for a variable engine mount, wherein the changing means changes a ratio between a period in which air is supplied by the switching valve and a period in which air is discharged by the switching of the combustion mode. 10. The control device for a variable engine mount according to claim 9, wherein the control means adjusts the flow resistance of the air flowing through the passage which controls at least one of supply and discharge of air to and from the air chamber. And a control device for the variable engine mount, wherein the changing means changes the flow resistance of the air by the adjusting means when the control mode is changed. 11. The variable engine mount control device according to claim 9, wherein switching between supply and discharge of air to said air chamber is performed a plurality of times for each explosion cycle of said engine. 12. The variable engine mount control device according to claim 11, wherein said changing means changes the number of times of switching between supply and discharge of the air when changing the control mode.