JP3185733B2 - Variable vibration isolator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration bearing device for supporting an internal combustion engine on a body of an automobile or the like, and more particularly to a variable anti-vibration support device in which the anti-vibration characteristics are variably controlled in accordance with input vibration characteristics. About.

[0002]

2. Description of the Related Art In an automobile or the like, various types of vibration are used as a device for supporting an internal combustion engine on the vehicle body side in order to prevent various vibrations such as idle vibration of the internal combustion engine and engine shake from being transmitted to the vehicle body side. 2. Description of the Related Art A variable anti-vibration bearing device that realizes anti-vibration characteristics according to characteristics is used.

[0003] As such a variable vibration isolation support device, an active mount described in Japanese Patent Application Laid-Open No. 6-16050 is known. The active mount includes a rubber material and a liquid seal communicated with a variable orifice. The active mount has an opening area of the variable orifice that is variable according to the vibration characteristics of the input side. The spring constant is varied. As for the timing for changing the dynamic spring constant of the active mount, a cylinder discrimination signal output each time the camshaft of the engine makes one rotation and a crank angle signal output each time the crankshaft rotates a predetermined crank angle are provided. Using
The cylinder which undergoes the explosion stroke and the explosion time of the cylinder are predicted, and the dynamic spring constant of the active mount is changed a predetermined time before the predicted explosion time.

On the other hand, in an internal combustion engine, Japanese Unexamined Patent Application Publication No.
As described in Japanese Patent Publication No. 24967, there is known a technique of correcting the ignition timing for each cylinder in order to suppress the fluctuation of the engine speed during idling. In the internal combustion engine controlled as described above, at the time of idling, since the ignition timing differs for each cylinder, the explosion timing also differs.

[0005]

However, in the technique described in Japanese Patent Laid-Open No. 6-16050, it is assumed that all cylinders have the same ignition timing, that is, all cylinders have the same explosion timing. As the dynamic spring constant of the active mount is changed a certain time before the explosion time, the timing of changing the dynamic spring constant is actually shifted, and a sufficient vibration damping effect cannot be obtained. There was a case.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a variable vibration isolation device capable of obtaining a sufficient vibration isolation effect even when the ignition timing differs for each cylinder when the internal combustion engine is idling. It is intended to provide a bearing device.

[0007]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the variable vibration isolating bearing device according to the present invention has a vibration isolating characteristic that can be changed, vibration isolating bearing means for supporting the internal combustion engine so as not to transmit the vibration of the internal combustion engine to the vehicle body side, Independently changing the ignition timing or the fuel injection timing to substantially change the explosion timing, and the anti-vibration characteristics of the anti-vibration support means before the next explosion of the cylinder in which the explosion is predicted. upon change, the change timing of vibration damping characteristics of the vibration isolating support unit, and a vibration isolating characteristic changing timing changing means for changing in accordance with the explosion timing of the cylinder that has been changed by the explosion timing changing means, said proof The vibration characteristic change time varying means is provided with
Explosion timing is advanced from the reference timing by the departure timing variable means
If it is changed to anti-vibration,
The characteristic change timing is corrected to be more advanced than the reference timing, and
When the explosion time is changed to the retard side from the reference time
Is based on the timing of the change of the damping characteristics according to the magnitude of the change.
It is characterized in that correction is made to the retard side from the quasi-time .

When the explosion timing of a certain cylinder is changed by the explosion timing changing means, the vibration damping characteristic changing timing changing means changes the timing of changing the vibration damping characteristic of the vibration damping support means according to the explosion timing of the cylinder. Therefore, even if the explosion timing differs for each cylinder, the vibration damping function can be sufficiently exhibited.

[0009]

In the case where the internal combustion engine is of a spark ignition type such as a gasoline engine, the explosion timing changing means can be configured to change the ignition timing to substantially change the explosion timing. In the case of a compression ignition type such as a diesel engine, the explosion timing changing means can be configured to change the fuel injection timing to substantially change the explosion timing.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which a variable vibration isolating bearing device according to the present invention is applied. The internal combustion engine 1 is an in-line six-cylinder internal combustion engine.
The first cylinder (# 1) 19, the second cylinder (# 2) 20, the third cylinder (# 3) 21, the fourth cylinder (# 4) 22, the fifth cylinder (#
5) 23, and 6th cylinder (# 6) 24, each cylinder 1
An ignition plug 25 is attached to each of 9 to 24.

Subsequently, the intake branch pipe 2 is provided in each of the cylinders 19 to 24.
Are connected, and these intake branch pipes 2 are connected to a surge tank 3. A fuel injection valve 26 is attached to each of the intake branch pipes 2 so that the injection hole faces an intake port (not shown).

The surge tank 3 is connected to an air cleaner box 5 via an intake pipe 4. The intake pipe 4 has a throttle valve 6 for opening and closing a passage in the intake pipe 4 in conjunction with an accelerator pedal (not shown). It is attached.
In the intake system configured as described above, the throttle valve 6
Is opened, the fresh air that has passed through the air cleaner box 5 flows into the surge tank 3 via the intake pipe 4, and the surge pulsation in the surge tank 3 smoothes the intake pulsation.
24 for distribution and supply.

Further, a bypass passage 2 for communicating the upstream and downstream of the throttle valve 6 with the intake pipe 4 is provided.
The idle speed control valve (ISCV) 28 for adjusting the flow rate of fresh air flowing in the bypass passage 27 is attached to the bypass passage 27.

The idle speed control valve 28 comprises a valve element which repeats opening and closing, and a solenoid for driving the valve element, and has a drive pulse having a duty ratio corresponding to the ratio between the fully open time and the fully closed time of the valve element. When a signal is input, the solenoid drives the valve element according to the drive pulse signal to adjust the air flow rate in the bypass passage 27.

Further, each of the cylinders 19 to 24 has an exhaust branch pipe 8.
Are connected, and the exhaust branch pipe 8 is connected to the exhaust pipe 9.
Next, the internal combustion engine 1 is supported on the vehicle body side 10 of the automobile by a variable engine mount 11, an engine mount 12, and the like.

The variable engine mount 11 is shown in FIG.
As shown in FIG. 3, an outer cylinder 32 having an open upper portion, and a disk-shaped rigid body having an outer diameter substantially the same as the inner diameter of the outer cylinder 32, and the inside of the outer cylinder 32 is divided into two upper and lower chambers. And a partition plate 33 made of an elastic material such as rubber.
And a vibration isolating base 35 which is press-fitted into a space above the outer cylindrical fitting 32 and is fixed to the outer cylindrical fitting 32;
And a vibration-proof base 36 fixed to the base 2.

By fixing the vibration-isolating base 35 to the internal combustion engine 1 with bolts 42 and fixing the outer cylindrical fitting 32 to the vehicle body side 10 of the automobile with bolts 43,
The internal combustion engine 1 is supported on a vehicle body 10 via a variable engine mount 11.

Subsequently, a space is formed above the partition plate 33 so as to be surrounded by the vibration-proof base 35 and the partition plate 33, and the periphery of the space is fixed to the partition plate 33. It is divided into a space 37 and a space 41 by a diaphragm 39. And in the space part 37,
The liquid is enclosed (hereinafter, the space portion 37 is referred to as a working fluid chamber 37).

A space 38 is formed below the partition plate 33 of the variable engine mount 11 so as to be surrounded by the vibration-isolating base 36 and the partition plate 33. Is filled with a liquid. The working fluid chamber 37 and the space 38 communicate with each other via an orifice 40 formed in the partition plate 33.

Further, the partition plate 33 and the outer tube fitting 32 have a communication passage 3 for communicating the space 41 with the outside.
The communication passage 34 communicates with the vacuum switching valve VSV16.

Here, the VSV 16 is connected to the communication passage 34 and connected to the intake pipe 4 upstream of the throttle valve 6 and the second passage connected to the surge tank 3. 18 is connected to the communication passage 34 and the first passage 17 (the second passage 18 is closed), and the communication between the communication passage 34 and the second passage 18 (the first passage 17). And a solenoid that drives the valve in response to a control signal from the ECU 15.

Then, the communication path 3 is established by the VSV 16.
When the first passage 17 communicates with the first passage 17, the atmosphere (pressure) flowing through the intake pipe 4 is introduced into the space 41 of the variable engine mount 11, as shown in FIG. At the same time, the volume of the working fluid chamber 37 is reduced, and as a result, the pressure inside the working fluid chamber 37 is increased. By increasing the pressure in the working fluid chamber 37 in this manner, the variable engine mount 11 can absorb the input in the pulling direction.

On the other hand, the communication path 34 is
When the second passage 18 is communicated with the second passage 18, as shown in FIG. 3, the intake negative pressure in the surge tank 3 is introduced into the space 41 of the variable engine mount 11, and the air in the space 41 is sucked out. Then, the diaphragm 39 comes into close contact with the partition plate 33. Thereby, the volume of the working fluid chamber 37 is increased at the same time as the volume of the space portion 41 is reduced.
The pressure in 7 is reduced. By reducing the pressure in the working fluid chamber 37 in this manner, the variable engine mount 11
Can absorb input in the compression direction.

As described above, the variable engine mount 11 and the V
The SV 16 realizes the vibration-proof support means according to the present invention.
Returning to FIG. 1, the internal combustion engine 1 includes a crank position sensor 13 that outputs an electric signal each time a crankshaft (not shown) rotates a predetermined angle (for example, 10 degrees).
Also, a sensor such as a cylinder discriminating sensor 14 that outputs an electric signal when the rotational position of the camshaft (not shown) is at a predetermined position is attached. The intake pipe 4 is provided with an air flow meter 7 for outputting an electric signal corresponding to the intake mass flowing through the intake pipe 4.

The cylinder discriminating sensor 14 is an electromagnetic pickup type sensor, and outputs an electric signal before the compression top dead center of the reference cylinder. At this time, the cylinder discrimination sensor 14 is set, for example, so that the signal output from the crank position sensor 13 immediately after the output of the cylinder discrimination sensor 14 becomes 10 ° before the compression top dead center of the reference cylinder.

Next, the ECU 15 is composed of a digital computer, and ROMs connected to each other by a bidirectional bus.
(Read-on memory), RAM (random access memory), CPU (central processor unit), input port, output port.

The ROM stores a fuel injection amount control routine for determining a fuel injection amount for each of the cylinders 19 to 24.
24, a fuel injection timing control routine for determining the fuel injection timing, an ignition timing control routine for determining the ignition timing of each of the cylinders 19 to 24, an ISCV control routine for determining the target opening of the ISCV 28, and a switching timing for the VSV 16. Application programs such as a VSV switching timing control routine to be executed and various control maps. The control map is, for example, a map A indicating the relationship between the ignition timing correction value during idling, the engine speed, and the switching timing correction value of the VSV 16.

The map A indicates that when the internal combustion engine 1 is idling,
Even if the ignition timing differs for each cylinder, a correction value for optimizing the switching timing of the VSV 16 according to the ignition timing of the cylinder in the explosion stroke is set in order to sufficiently bring out the vibration damping effect of the variable engine mount 11. It is a map. FIG. 4 shows an example of this map A. When the correction value of the ignition timing and the engine speed are determined, the map A is used to specify the optimum switching timing correction value of the VSV 16. I have.

Further, the RAM of the ECU 15 stores output signals from the respective sensors, calculation results of the CPU, and the like. The calculation result is, for example, the crank position sensor 13
And the engine load calculated from the output signal of the air flow meter 7 (intake air mass) and the engine speed. The output signal from each sensor, the calculation result of the CPU, and the like are updated each time the crank position sensor 13 outputs a signal.

Next, the CPU of the ECU 15 executes the R
It operates according to an application program stored in the OM, determines a fuel injection amount, a fuel injection timing, an ignition timing, and the like of each cylinder based on an output signal of each of the sensors and a control map stored in the RAM. The valve 26, the spark plug 25, the VSV 16, and the ISCV 28 are controlled.

When controlling the ISCV 28, the ECU 1
5 calculates a target idle speed corresponding to the operating state of the internal combustion engine 1, calculates an actual engine speed from an output signal of the crank position sensor 13, and then calculates the target idle speed and the actual engine speed. Then, an optimum duty ratio is calculated in order to reduce the deviation between them. Then, the ECU 15 applies a pulse signal corresponding to the duty ratio to the ISCV 28, and performs control so that the actual engine speed becomes the target idle speed.

When controlling the spark plug 25 at the time of idling, the ECU 15 performs an explosion stroke (1) for each of the cylinders 19 to 24.
80 CA) and measure the time required for all cylinders 19-
Comparing the time required for the 24 explosion strokes, all cylinders 19 to
The ignition timing is corrected for the cylinder that took the longest time or the cylinder that took the shortest time so that the deviation of the time required for the explosion stroke of Example 24 was minimized. Control is performed to suppress fluctuations. In this embodiment, by correcting and changing the ignition timing for each cylinder, the explosion timing for each cylinder is substantially changed, and the ECU 15 independently sets the ignition timing for each cylinder at idle. By executing the ignition timing correction control routine to be corrected, the explosion timing variable means according to the present invention is realized.

When controlling the VSV 16 to prevent idle vibration of the internal combustion engine 1, the ECU 15 controls the ignition timing of each of the cylinders 19 to 24 (or the timing of the explosion stroke).
Thus, the vibration direction of the internal combustion engine 1 generated by the combustion of the air-fuel mixture in each of the cylinders 19 to 24 is determined, and the VSV 16 is switched and controlled so as to absorb the vibration in the vibration direction. Here, the internal combustion engine 1 tends to rotate in the direction of rotation of the crankshaft (not shown) for each explosion stroke of each of the cylinders 19 to 24. At this time, a force in the compression direction is applied to the variable engine mount 11. . Therefore, the ECU 15 sets the communication path 3
The switching of the VSV 16 is controlled so that the hydraulic fluid 4 communicates with the second passage 18, and the hydraulic fluid chamber 37 is depressurized following the vibration of the internal combustion engine 1. At this time, since the dynamic spring constant of the variable engine mount 11 becomes lower following the vibration in the compression direction, the vibration in the compression direction is absorbed by the variable engine mount 11.

Subsequently, when the internal combustion engine 1 rotates in the opposite direction due to the reaction of the rotation described above, a force in the pulling direction is applied to the variable engine mount 11. Therefore,
The ECU 15 controls the switching of the VSV 16 so that the communication passage 34 and the first passage 17 communicate with each other, and increases the pressure of the hydraulic fluid chamber 37 following the vibration of the internal combustion engine 1. At this time, since the dynamic spring constant of the variable engine mount 11 increases following the vibration in the tension direction, the vibration in the tension direction is absorbed by the variable engine mount 11.

Further, the ECU 15 determines whether the VSV 1
When switching control of the cylinders 6, the cylinders 19 to 24 are used in order to sufficiently exhibit the vibration-proof function of the variable engine mount 11.
The switching timing of the VSV 16 is optimally corrected according to the ignition timing.

Here, before describing the present embodiment,
A conventional VSV switching control method will be described with reference to FIG. In FIG. 5, (A) shows the passage of time of the crank angle, and (B) is a switching timing chart of the conventional VSV 16. In the internal combustion engine 1, it is assumed that the second cylinder explodes next to the first cylinder as the explosion order.
Now, the ignition timing of the first cylinder is set when the crank angle is advanced by, for example, 10 degrees from the reference ignition timing at idling, and the ignition timing of the second cylinder is set at, for example, 5 crank angles from the reference ignition timing at idling. It shall be set when the angle is retarded. Conventionally, the switching timing of the VSV 16 is always set to the same timing, assuming that all cylinders are ignited at the reference ignition timing, despite the fact that the ignition timing differs depending on the cylinder. As a specific control example, as shown in FIG. 5B, the elapsed time is measured based on a predetermined time before the compression top dead center of each cylinder, and a predetermined time T
_{When 0} has elapsed, the VSV 16 has been switched so that the communication path 34 and the second path 18 communicate with each other. In other words,
Assuming that all cylinders are ignited at the reference ignition timing,
The switching timing of the VSV 16 is set to a certain time before the compression top dead center. In this case, VSV16 for the first cylinder
Is too late, and the switching timing of the VSV 16 is too early for the second cylinder. That is,
The timing of changing the dynamic spring constant of the VSV 16 slightly deviates from the actual explosion timing of each cylinder, and a sufficient vibration-proof effect cannot be obtained.

Therefore, in the present embodiment, when the ignition timing is changed to a more advanced side than the reference ignition timing, the switching timing of the VSV 16 is set to be longer than the reference switching timing by a predetermined time in accordance with the magnitude of the change. When the ignition timing is changed to the retard side from the reference ignition timing, the switching timing of the VSV 16 is also retarded by a predetermined time from the reference switching timing according to the magnitude of the change. Side correction. Therefore, the elapsed time is measured on the basis of a predetermined time before the compression top dead center of each cylinder, and when the switching time T elapses, VSV1
6, the switching time T is set by adding the switching timing correction value t to the reference switching time T ₀ (that is, T = T ₀ + t). And VSV16
The switching time correction value is determined using map A shown in FIG. In this map A, the ignition timing correction value “0” means that the ignition timing is the reference ignition timing, and at that time, the switching timing correction value t of the VSV 16 is also “0”.
Becomes, so that the VSV16 is switched after the reference switching time T _0.

The operation and effect of this embodiment will be described below. When the ECU 15 determines that the internal combustion engine 1 is in the idle state, the ECU 15 executes the VSV switching timing control routine shown in FIG. 6 every time the crankshaft rotates a predetermined crank angle (between explosion strokes).

First, in step 101, the ECU 15 determines which cylinder is the next cylinder in the explosion stroke based on the output signals of the crank position sensor 13 and the cylinder discriminating sensor 14 (hereinafter simply referred to as cylinder). Means the cylinder determined in step 101).

Next, at step 102, the ECU 15 accesses the RAM and reads the ignition timing correction value of the cylinder determined by the ignition timing control routine executed in parallel with the VSV switching timing control routine.

Subsequently, the ECU 15 accesses the RAM at step 103 to read the current engine speed of the internal combustion engine 1. Next, the ECU 15 determines in step 104
Access to the map A of the ROM at step 10
2, the switching timing correction value t of the VSV 16 corresponding to the ignition timing correction value obtained in step 2 and the engine speed obtained in step 103.
Is calculated.

Further, in step 105, the ECU 15 sets the reference switching time T ₀ of the VSV 16 to step 10.
The switching time correction value t calculated in step 4 is added to calculate the optimum switching time T of the VSV 16 for the ignition timing of the cylinder, and the calculated switching time T is stored in a predetermined area of the RAM.

Next, in step 106, the ECU 15 counts up from a reference time point (a timer start point in FIG. 5) which is a predetermined crank angle before the compression top dead center of the cylinder, and the switching time T calculated in step 105. Is determined.

If it is determined in step 106 that the switching time T has not elapsed, the ECU 15 sets the VSV1
The count-up of the elapsed time is continued without performing the switching of step 6.

If it is determined in step 106 that the switching time T has elapsed, the ECU 15 executes step 1
At 07, the VSV 16 is switched so that the communication path 34 and the second path 18 communicate with each other. Thus, the ECU 1
5 implements the anti-shake characteristic change timing varying means according to the present invention by executing the VSV switching timing control routine.

FIG. 5C shows the VS according to the present embodiment.
It is a switching timing chart of V16. Also in the case of the present embodiment, the ignition timing conditions for the first cylinder and the second cylinder are the same as those of the above-described conventional example. From this timing chart, according to the present embodiment, when the ignition timing is advanced to the reference ignition timing as in the first cylinder, V
When the switching timing of the SV16 is changed to be more advanced than the reference switching timing and the ignition timing is changed to be more retarded than the reference ignition timing as in the second cylinder, the switching timing of the VSV16 is also changed from the reference switching timing. Is also changed to the retard side.

As described above, according to this embodiment, when the internal combustion engine 1 is idling, V is set according to the ignition timing of each cylinder.
Since the switching timing of the SV 16 is changed, the vibration isolating function of the variable engine mount 11 can always be sufficiently exhibited, and the vibration isolating performance at the time of idling can be improved.

[0049]

According to the variable vibration isolating support device of the present invention, the timing of changing the vibration isolating characteristics of the vibration isolating support means is changed according to the explosion timing of each cylinder. Even if the explosion times are different, the anti-vibration function of the anti-vibration support means can be sufficiently exhibited, and the anti-vibration performance at the time of idling is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which a variable vibration isolation support device according to the present invention is applied.

FIG. 2 is a diagram showing a schematic configuration of an anti-vibration support means.

FIG. 3 is a view for explaining the operation of the vibration isolating support means.

FIG. 4 is a diagram showing a specific example of a map A showing a relationship between an ignition timing correction value during idling, an engine speed, and a VSV switching timing correction value.

FIG. 5 is a diagram showing a specific example of a VSV switching timing chart showing a comparison between the related art and the present invention.

FIG. 6 is a flowchart illustrating a VSV switching timing control routine;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 11 ... Variable engine mount 14 ... Cylinder discrimination sensor 15 ... ECU 16 ... VSV 25 ... Spark plug 28 ... Idle speed control valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02P 5/15 F16F 15/02 B F16F 13/26 F02P 5/15 E 15/02 F16F 13/00 630D (58) (Int.Cl. ⁷ , DB name) B60K 5/12 F02D 41/36 F02D 43/00 F02P 5/15 F16F 13/26 F16F 15/02

Claims (1)

(57) [Claims] An anti-vibration support means capable of changing an anti-vibration characteristic, supporting an internal combustion engine so as not to transmit vibration of the internal combustion engine to a vehicle body, and independently controlling ignition timing or fuel for each cylinder of the internal combustion engine. An explosion timing variable means for substantially changing the explosion timing by changing the injection timing; and when changing the vibration isolating characteristics of the vibration isolating support means before an explosion of a cylinder in which an explosion is predicted, the vibration isolating support means The vibration damping characteristic change timing of the cylinder is changed according to the explosion timing of the cylinder changed by the explosion timing variable means, and the vibration damping characteristic change time variable means , The explosion time variable hand
Explosion time has been changed to the advanced side from the reference time by the step
In case, when the anti-vibration characteristics change according to the magnitude of the change
Phase is advanced to the reference timing, and the explosion
If it has been changed to a more retarded side than the sub-term,
The time to change the anti-vibration characteristics according to the size is later than the reference time
A variable vibration isolation support device characterized in that it is corrected to the corner side .