JP3227904B2 - Active engine mounting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an active engine
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting device, and more particularly to an active engine mounting device for actively reducing engine noise of an automobile or the like.

[0002]

2. Description of the Related Art In recent years, the demand for comfort of automobiles and the like is high.
Low vibration and low noise engines are in progress. Vibration that is a problem in the engine idle rotation region is caused by engine roll resonance due to uneven combustion between cylinders or cycles,
So-called swaying vibration (about 7 to 15 Hz) and explosion 1
This is a pulsating vibration (approximately 20 to 35 Hz) that is caused mainly by torque fluctuation due to the next component. Further, in the high rotation region, there is a problem of the vibrating force due to the reciprocating inertial force of the engine motion system.

[0003] One of the elements to meet this demand is to improve an engine mount provided between the engine and the vehicle body. In order to cope with the above problem, the engine mount must be mounted in an idling region of the engine. It is necessary that the damping of the low frequency vibration be large and the transmission rate in the high rotation region be small.

FIG. 6 is a graph referred to when comparing the characteristics of the vibration isolating rubber. The vertical axis is 100Hz
, The dynamic magnification Kd / Ks (ratio of dynamic spring to static spring constant) is taken, and the horizontal axis shows the loss factor tan δ at 10 Hz. The vertical axis indicates the degree of vibration transmission, and the horizontal axis indicates the degree of vibration attenuation. A desirable engine mount characteristic is in the lower right direction.

As described above, conventionally, rubber materials have been generally used for engine mounts, but for the past ten years or so, rubber has not been obtained only for the purpose of improving low-frequency vibration such as shaking. In order to generate a large damping force, an active engine mounting device having a liquid working part (liquid-filled mount) has been developed.

FIG. 7 shows an outline of a conventional active engine mounting apparatus, in which A denotes a coil a1.
And a diaphragm a2, and an electromagnetic actuator section constituted by a diaphragm a2, and B denotes a liquid operating section (liquid enclosing mount). The electromagnetic actuator part A and the liquid operating part B constitute an engine mount in a metal outer cylinder part c1, and this engine mount is controlled by a controller (not shown).

The liquid operating section B includes liquid chambers b1 to b5 for filling oil, ethylene glycol, etc., between the liquid chambers b1 and b2 and between the liquid chambers b3 and b4.
And orifices b6 and b for sucking and discharging liquid
7 respectively, and further supported by supporting rubbers b8 and b9. In addition, b10 is a metal part, a
3 and b11 are rubber parts.

In such an active engine mounting apparatus, the number of rotations (frequency) of the engine is determined as follows using a controller (not shown) connected thereto.
Is controlled by

When the input frequency is low (about 20H
z): The vibration is attenuated in the liquid operating section B without driving the actuator section A. Between the liquid chamber b1 and the liquid chamber b2,
By absorbing and discharging the oil filled therein through the orifices b6 and b7 between the liquid chamber b3 and the liquid chamber b4, the vibration energy of the engine is converted into heat energy to attenuate the vibration. Further, the electromagnetic actuator A is partially driven to reduce the amplitude. The sectional area of the liquid working chamber and the areas of the orifices b6 and b7 are determined so as to correspond to the shake near idle.

When the input frequency is high (about 20 Hz
-): Since the inertia of the internal oil increases and the suction and discharge between the liquid chambers stops (locks), the driving of the actuator A causes the diaphragm a2 to swing in the opposite phase of the engine rotation, thereby canceling the input amplitude. Further, the internal pressure is controlled by the amplitude of the actuator section A to prevent the dynamic spring from becoming high, thereby preventing transmission of high-frequency vibration.

A typical example of such an active engine mounting device is disclosed in Japanese Patent Application Laid-Open No. 4-362331 and Japanese Patent Application Laid-Open No. 3-24338. The combination of a liquid operating section and an electromagnetic actuator section over the entire engine rotation range. The aim is to reduce the vibration of

[0012]

The above-described active engine mounting apparatus is higher in cost than the conventional engine mounting apparatus, and the feasibility as a product is determined by whether or not sufficient performance can be obtained near idle rotation. It depends on the crab.

However, in a four-cylinder large-displacement diesel engine such as a light-duty truck, as shown in FIG.
In order to obtain an effective reduction in the engine mounting device, it is necessary to match the amplitude of the electromagnetic actuator with the vibration amplitude of the engine.

Although it is technically possible to increase the vibration amplitude of the actuator, as a result, the area of the actuator becomes large and the size of the vibration amplifier becomes large. This means that the layout establishment becomes difficult. In particular, in the case of a narrow-type light truck, an RV vehicle, or the like having a narrow vehicle width, the interval between the engine and the frame is narrow, and it is difficult to establish a layout. This is the "first problem".

The "second problem" is that the idle vibration which can be dealt with by controlling the actuator section is only the primary component of the explosion and cannot be dealt with by vibration such as shake. This shake and the like are supported by the liquid hydraulic section, but if there are multiple roll resonances of the engine at around 1000 rpm,
It is common to chew two ring to aim at the one frequency, sufficient effect can not be obtained in the case of other things.

That is, this is called an engine shake, and has a characteristic observed on the floor of the vehicle interior as shown in FIG. In this case, the peak is around 500 rpm and 10
It occurs characteristically in two places near 00 rpm. Generally, the mount is tuned aiming at the shake at idle rotation, but in such a case, the peak frequency of the shake is different, so if you set it to one of the frequencies, the effect of the other will not be obtained much . It is generally known that the liquid operating portion has a non-linear characteristic that is structurally dependent on the input amplitude. This is because the engine vibration amplitude near idle of a large-displacement four-cylinder diesel vehicle has an exponential function with respect to the engine rotation. This is supported by the decrease in

The “third problem” is that the liquid mount and
In order to effectively reduce the shake at idling that cannot be handled by the electromagnetic actuator, or the bulbling vibration, the dynamic spring coefficient of the supporting rubber in the liquid working part is shown by the following formula,

[0018]

(Equation 1)

When the dynamic spring is set low with an emphasis on the improvement of idle performance, the engine displacement becomes large, the steering stability is deteriorated, there is a possibility of interference between the vehicle body and exhaust pipes, engine accessories and the like, or the durability of the engine mount. There are problems such as deterioration of sex.

Accordingly, the present invention provides an engine mout comprising an electromagnetic actuator provided between an engine and a vehicle body and a liquid operating part having an orifice between liquid chambers;
And a controller for driving the electromagnetic actuator based on a rotation synchronizing signal of the engine.
It is an object of the present invention to reduce the engine vibration amplitude near idle rotation of the engine without changing the layout of the peripheral portion of the engine or the characteristics of the support rubber in the liquid operating section.

[0021]

In order to solve the above-mentioned problems, an active engine mounting apparatus according to the present invention has an orifice having an opening with a variable cross-sectional area connected to a step motor, and a controller. However , when an engine rotation speed equal to or lower than the upper limit value of the idle rotation region is detected from the engine rotation synchronization signal, the peak of the engine shake is reduced in advance according to the engine rotation speed without driving the electromagnetic actuator unit. only rotation angle corresponding to the orifice diameter by driving the step motor is for controlling the cross-sectional area of the opening of the orifice, further body
An error sensor for generating an error signal is provided on the
The controller further reduces the rotation angle obtained by the error signal to a minimum value.
It is characterized in that correction is made so that

[0022]

Further, according to the present invention, the orifice has an opening having a variable cross-sectional area connected to the stepping motor, and the controller receives an error signal from an error sensor provided on the vehicle body side and receives an idle signal from the engine rotation synchronizing signal. When an engine speed less than or equal to the upper limit value of the rotation range is detected, the step motor may be driven to adaptively control the error signal to a minimum while controlling the cross-sectional area of the opening of the orifice.

[0024]

According to the present invention, when the controller detects an engine rotation speed equal to or less than the upper limit value (about 1000 rpm) of the idle rotation region from the engine rotation synchronization signal, the stepping motor is rotated by a rotation angle obtained in advance corresponding to the engine rotation speed. Drive.

The relationship between the engine speed and the rotation angle is as follows:
The rotation angle of the step motor corresponding to the orifice diameter (cross-sectional area) that attenuates the peak of the engine shake as shown in FIG. 9 below the upper limit value of the idle rotation region is obtained (stored) in advance. is there.

When the rotation angle obtained in this way is given to the step motor, the step motor controls the opening of the orifice to change its cross-sectional area.

Therefore, the dynamic spring constant of the engine mount changes in accordance with the cross-sectional area of the orifice, so that the peak of the engine shake shown in FIG. 9 can be appropriately attenuated.

Further, the controller to the output signal of error sensor provided on the vehicle body side is minimum, the said further said error signal rotation angle determined is that to correct so as to minimize
Thus, a more optimal orifice cross-sectional area can be obtained, and the peak of the engine shake can be attenuated.

In addition, in the above case, the controller does not drive the electromagnetic actuator in the engine mount. However, the step motor can be appropriately controlled without using the relationship between the engine speed and the rotation angle of the step motor as described above. The control may be performed, and the result of this control may be fed back to an error signal from an error sensor provided on the vehicle body side to perform adaptive control such that the error signal is minimized.

[0030]

1 shows an active engine according to the present invention.
1 shows an embodiment of a mounting apparatus applied to a four-cylinder large-displacement diesel engine for a small truck or the like.

In this embodiment, an engine mount 3 composed of an electromagnetic actuator section A and a liquid operating section B (schematically shown in FIG. 1) is provided between the engine 1 and the vehicle body 2. A controller 4 is connected to the mount 3.

The controller 4 receives an engine rotation synchronizing pulse (an engine speed sensor is not shown) and supplies an actuator driving circuit 41 for giving a control signal to the electromagnetic actuator section A of the engine mount 3; And an orifice control circuit 42 for supplying a control signal to the step motor 5 connected to an engine intake negative pressure source (not shown) of the step motor.

The orifice control circuit 42 detects the engine speed from the engine speed synchronizing pulse and makes a determination, and the engine speed detected and determined by the engine speed detection / determination circuit 421. It comprises a memory map 422 for obtaining the rotation angle of the step motor 5 based on the number, and a circuit 423 for performing output correction based on the output signal of the memory map 422 and providing the output to the step motor 5.

The actuator drive circuit 41 (and, if necessary, the output correction circuit 423) receives an error signal from an error sensor (eg, acceleration sensor, vibration sensor, displacement sensor) 6 provided on the vehicle body 2 as a feedback signal. . Further, the step motor 5 is connected to a liquid operating section B of the engine mount 3 via an output cable 7.

FIG. 2 is a detailed view of the step motor 5 and the liquid operating portion B of the engine mount 3 schematically shown in FIG. 1, and FIG. 2 (1) is shown in FIG. The state where the diameter of the orifice b6 in the engine mount is minimum is shown, and FIG. 2B shows the state where the diameter of the orifice b6 is maximum.

In other words, the opening of the orifice b6 is provided with a diaphragm 10 which is often seen in a camera, and the diaphragm 10 is moved by an opening adjustment lever 11. The pulling force is constantly applied by the return spring 12 to return to the state shown in FIG.

Accordingly, in the case of FIG. 1A, the step motor 5 does not pull the lever 11 through the cable 7, and in the case of FIG. In this state, the lever 11 is pulled to the maximum extent.

FIG. 3 is a flowchart for explaining the operation of the controller 4 shown in FIG. 1. Hereinafter, the operation of the embodiment of the present invention shown in FIGS. 1 and 2 will be described with reference to this flowchart. .

First, the controller 4 turns on the engine key.
Is confirmed (step S1), the engine rotation synchronization pulse is read from a sensor (not shown) by the detection / determination circuit 421 to detect the engine rotation speed (step S2).

Next, it is determined whether or not the engine speed is in a low speed range of about 1000 rpm or less, which is the upper limit of the idle speed range as shown in FIG. 9 (step S).
3).

If it is determined that the speed is 1000 rpm or more, the memory map 422
Supplies a rotation angle signal that locks to the minimum orifice diameter to the step motor 5 through the output correction circuit 423 (step S4). As a result, the orifice b6 assumes the minimum diameter state shown in FIG. The minimum orifice diameter is a value that can absorb high-frequency micro-vibration calculated or experimentally obtained in advance.

As described above, while the orifice diameter is kept at the minimum value, the driving operation of the actuator driving circuit 41 in the following steps S5 to S8 is executed to reduce the vibration mainly caused by the reciprocating inertial force of the motion system of the engine 1. Actuator part A of engine mount 3
Drive.

First, the actuator drive circuit 41 reads an error signal from the error sensor 6 and an engine rotation synchronizing pulse indicating a primary explosion component which is a main component of the reciprocating inertia force of the engine (step S5).

Then, such an engine rotation synchronizing pulse is used as a reference signal R (n), and an error signal e (n) is used as a vertical component signal of an engine vibration component.
Calculation is performed using a well-known LMS algorithm or the like so that (n) is minimized, and a control signal for the electromagnetic actuator unit A is output (step S6). In this case, the operation formulas shown in the figure are n tap coefficients h (0) to h (n-1) when multiplying the output signal of the delay element for delaying the reference signal R (n) for each sample. And μ is the step size.

By performing a convolution operation in which such a tap coefficient is multiplied by the reference signal R (n) and added, an error signal evaluation value J expressed by a square value of the error signal e (n) is obtained.
It is determined whether n = e (n) ² is the minimum value (step S
7) If the value is not the minimum value, the output value to the electromagnetic actuator unit A is updated (step S8) and step S8 is performed.
Steps S6 and S7 are executed, but when the minimum value is reached, the process returns to step S5 to execute the LSM algorithm operation from the beginning.

On the other hand, if it is determined in step S3 that the engine speed is equal to or less than 1000 rpm, the flow advances to step S9 to execute orifice control using the memory map 422.

This step S9 is shown in detail in FIG. 4. First, the rotation angle θ of the step motor 5 corresponding to the engine speed read in step S2 is read from the memory map 422 (step S91).

Next, the memory map 422 is
Is given to the step motor 5.
After that, the error signal e (n) is evaluated. This is because the engine vibration is constantly changing depending on the engine state and the vibration is also changing, so that it is necessary to correct the output of the memory map 422 to obtain the optimum rotation angle θ. However, this correction is not indispensable and is more preferable. In this embodiment, the correction is performed so that the error signal is minimized.

That is, the previous error signal e (n) is compared with the current error signal e (n + 1) (step S92).
When it is found that (n)> e (n + 1), the output correction circuit 423 performs output correction for sending the rotation angle θ of the step motor by kθ (k is a constant) (step S93), and proceeds to step S92. Return.

In step S92, e (n) ≦ e
When it is found that (n + 1), output correction for returning the rotation angle θ of the step motor by kθ / 2 is performed (step S94), and furthermore, error signals e (n) and e
It is determined whether or not the error with (n + 1) is within a certain allowable range α (step S95). If the error signal is outside the allowable range α and the error signal is largely changed, step S92 is performed.
And the same steps are repeated, but when it is found that the error signal is within the allowable range α and the error signal has the same value, it is determined that the minimum error has been obtained, and step S91 is performed.
And the error signal evaluation is executed from the beginning.

As described above, when the cross-sectional area of the opening of the orifice b6 changes, the dynamic spring constant of the engine mount 3 changes (decreases) as shown in the above equation (1), and the rubber becomes soft. The peaks P1 and P2 of the engine shake in FIG. 9 are reduced as shown by the dotted lines in FIG.

On the other hand, at step S3, when the engine speed is 10
When it is determined that the speed is equal to or less than 00 rpm, the process proceeds to steps S10 to S13 as indicated by the dotted line in FIG. 3 without using the memory map 422 as in step S9 in FIG. May be performed.

Steps S10 to S13 correspond to steps S5 to S8, respectively. The difference is that the latter relates to the control of the electromagnetic actuator section A from the actuator driving circuit 41, whereas the former relates to the step motor 5 This is a point related to the control.

Therefore, in step S11, step S
6 and outputs a control signal for the step motor 5.

[0055]

As described above, according to the active engine mounting apparatus of the present invention, the orifice between the liquid chambers of the engine mount has an opening with a variable cross-sectional area, and the idle rotation region of the rotation angle corresponding to the orifice diameter determined in advance in correspondence to the engine speed without driving the electromagnetic actuator portion when detecting the engine speed of the upper limit value or less, further, the error sensor provided on the vehicle body side corrected I by the adaptive control using the output signal, so as to reduce the peak of the engine shake by controlling the cross-sectional area of the opening of the orifice by driving the stepping motor by this rotating <br/> rotation angle Therefore, the following specific effects can be obtained.

(1) The engine shake and the like near the idle can be greatly reduced. Even if there are various peaks up to around 1000 rpm, it is possible to cope continuously and a remarkable vibration reduction effect is obtained. (2) Since the idle vibration corresponds to the direction of the liquid operating portion, the actuator does not have to correspond to the low frequency and large amplitude near the idle, so that the actuator can be reduced in size and weight, the layout can be easily established, and the vehicle width is narrow. The present invention can be applied to narrow-type small trucks, RV vehicles, and other types of vehicles having a narrow frame interval with the engine. (3) It is also effective when a torque reaction force is applied such as when the A / T vehicle and the D range brake are stopped. (4) It is effective for cranking vibration and key-off shake.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of an active engine mounting device according to the present invention.

FIG. 2 is an explanatory diagram of an orifice control operation in an engine mount used in the present invention.

FIG. 3 is a control operation flowchart of a controller used in the present invention.

FIG. 4 is a flowchart of an orifice map control operation in the controller used in the present invention.

FIG. 5 is a graph for comparing the effects of the present invention and a conventional example.

FIG. 6 is a dynamic characteristic map of a conventionally used rubber.

FIG. 7 is a cross-sectional view illustrating a configuration example of an engine mount in a conventional example.

FIG. 8 is a vibration amplitude characteristic diagram of an engine.

FIG. 9 is a vibration characteristic diagram of an engine shake observed on a vehicle cabin floor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Body 3 Engine mount A Electromagnetic actuator B Liquid operating part 4 Controller 41 Actuator drive circuit 42 Orifice control circuit b1-b5 Liquid chamber b6 Orifice 5 Step motor 6 Error sensor 10 Throttle part The corresponding parts are shown.

Claims (2)

(57) [Claims] 1. An engine mount comprising an electromagnetic actuator provided between an engine and a vehicle body and a liquid operating unit having an orifice between liquid chambers, and the electromagnetic actuator is mounted on the basis of a rotation synchronization signal of the engine. An orifice having an opening with a variable cross-sectional area connected to a stepper motor, wherein the controller comprises: When an engine rotation speed equal to or lower than the upper limit value of the idle rotation region is detected from the engine rotation synchronization signal, the peak of the engine shake is reduced in advance according to the engine rotation speed without driving the electromagnetic actuator unit. The step motor is driven by a rotation angle corresponding to the orifice diameter to open the orifice. It is for controlling the cross-sectional area of the part, further the
An error sensor for generating an error signal is provided on the vehicle body side.
The controller further adds the obtained rotation angle to the error signal.
An active engine mounting device characterized by a correction to a minimum . 2. An electromagnetic device provided between an engine and a vehicle body.
Liquid having an actuator section and an orifice between liquid chambers
An engine mount comprising an operating part;
Drive the motor section based on the rotation synchronization signal of the engine.
And a controller.
Active engine mount device that dampens dynamics
Wherein the orifice has a variable cross-sectional area connected to a stepper motor.
Opening provided by the controller on the vehicle body side.
-Receive an error signal from the sensor and
The engine speed below the upper limit value of the idle rotation region is
When the rotation speed is detected, the step motor is driven to
While controlling the cross-sectional area of the orifice opening, the error signal
Active control characterized by adaptive control of
Engine mounting device.