JP2008223978A - Active vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid-sealed active vibration control device capable of effectively restraining the occurrence of cavitation, when large vibration is input from a vibration source. <P>SOLUTION: This active vibration control device can change a vibration control characteristic of a liquid-sealed engine mount body 10 by control by a mount control device 100, and performs the following cavitation occurrence restraining control. When vibration input from the vibration source is large input, an electric current value of an electric current carried to an actuator part 30 for moving a movable member 23 for changing the volume of a main liquid chamber 21, is reduced more than when the vibration input from the vibration source is not the large input. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for suppressing the occurrence of cavitation in a liquid-filled active vibration isolator.

  As a vibration isolator (engine mount) provided between the engine and the vehicle body, a liquid sealed type is known. The liquid-sealed vibration isolator has, for example, a configuration including a main body rubber, a diaphragm, and a liquid chamber in which an incompressible liquid is sealed. The liquid chamber is partitioned into a main liquid chamber and a sub liquid chamber by a partition plate, and the main liquid chamber and the sub liquid chamber are communicated with each other via a restriction passage (orifice). In such a liquid-filled vibration isolator, when vibration from the vibration source is transmitted to the vibration isolator, the main rubber is elastically deformed, and the volume of the main liquid chamber is changed, and the liquid chamber is changed between the liquid chambers through the orifice. Liquid moves. A vibration damping force is generated by the resistance when the liquid passes through the orifice, and transmission of vibration from the vibration source is suppressed.

  Further, among the above-described liquid-filled vibration isolators, an active vibration isolator (active control engine) that can change the damping characteristics (anti-vibration characteristics) according to the vibration state input from the vibration source. Mount) is known. Specifically, the active vibration isolator drives the actuator according to the vibration state input from the vibration source and moves a movable member such as a movable plate (vibrating plate), thereby reducing the volume of the main liquid chamber. It is configured so as to cut off the transmission of vibration by changing.

As conventional examples of the active vibration isolator, for example, techniques as disclosed in Patent Documents 1 to 4 have been proposed.
JP 2003-4089 A JP 2003-4090 A JP 2006-2831 A Japanese Patent Laid-Open No. 10-306842

  By the way, in a liquid-filled active vibration isolator, when a large vibration is input from a vibration source, for example, during cranking or when the output torque of the engine is large, vibration transmission by this large input is performed. Therefore, the displacement of the movable member by the actuator increases. For this reason, the pressure fluctuation in the main liquid chamber accompanying the displacement of the movable member increases. In this case, when the pressure in the main liquid chamber fluctuates to the negative pressure side and becomes equal to or lower than the vapor pressure, cavitation may occur in the main liquid chamber, which may cause abnormal noise.

  Further, in the active vibration isolator, since the vibration isolating characteristic is changed by the displacement of the movable member by the actuator, the fluctuation in pressure in the main liquid chamber is provided with a non-active vibration isolator (actuator, movable plate, etc.). There is a possibility that it will be larger than (not vibration isolator). Therefore, there is a concern that a large cavitation is generated as compared with a non-active type vibration isolator.

  Further, in order to cut off the transmission of vibration by the active vibration isolator, it is necessary to cancel the vibration transmitted from the liquid chamber and the vibration transmitted from the main rubber by displacement of the movable member by the actuator. However, in order to cancel the vibration transmitted from the liquid chamber and the vibration transmitted from the main rubber, it is necessary to increase the displacement of the movable member by the actuator more than canceling the vibration transmitted from the liquid chamber. At this time, if the vibration transmitted from the main rubber is large, the pressure fluctuation in the main liquid chamber becomes large, and there is a concern that cavitation is likely to occur.

  The present invention has been made in view of such problems, and is a liquid-filled active type anti-corrosion that can effectively suppress the occurrence of cavitation when a large vibration is input from a vibration source. An object is to provide a vibration device.

  In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention is input from a main liquid chamber filled with an incompressible liquid, a movable member for changing the volume of the main liquid chamber, an actuator for moving the movable member, and a vibration source. And a sensor for discriminating a vibration state, wherein the actuator is driven by energization according to a vibration state input from a vibration source, and the volume of the main liquid chamber is changed by moving the movable member. In the active vibration isolator configured to be able to change the vibration isolation characteristics, when the vibration input from the vibration source is a large input, the current value of the current supplied to the actuator is input from the vibration source. It is characterized in that the generated vibration is reduced compared to the case where the input is not a large input.

  According to the above configuration, by reducing the current value of the current to the actuator, the displacement of the movable member by the actuator becomes smaller according to the degree of decrease in the current value. As the displacement of the movable member decreases, the pressure fluctuation in the main liquid chamber decreases according to the degree of decrease in the current value. Therefore, the pressure in the main liquid chamber is reduced to a predetermined pressure (vapor pressure) at which cavitation can occur. ) Can be maintained above, and the pressure of the main liquid chamber can be avoided from becoming a pressure equal to or lower than the vapor pressure. Accordingly, even when a large vibration is input from the vibration source, it is possible to suppress the occurrence of cavitation in the main liquid chamber, and it is possible to suppress the generation of abnormal noise. Further, since the amount of current to the actuator becomes small, power consumption can be suppressed. Therefore, according to the above configuration, cavitation can be suppressed without increasing power consumption.

  Here, a specific example of the sensor that detects the vibration state input from the vibration source includes a pressure sensor that detects the pressure of the main liquid chamber. In this case, if the pressure of the main liquid chamber by the pressure sensor is a pressure that can generate cavitation, it is determined that the vibration input from the vibration source is a large input. In this configuration, the sensor that detects the vibration state input from the vibration source is specified, and the determination accuracy of whether or not the vibration input from the vibration source is a large input is improved.

  Further, it is preferable that the current control to the actuator is performed only when the current value is negative. If it carries out like this, among the displacement of the movable member by an actuator, the displacement of the movable member corresponding to the area | region where the electric current value to an actuator is negative will become small compared with the displacement of the movable member corresponding to a positive area | region. As the displacement of the movable member decreases, the pressure fluctuation on the negative pressure side of the main liquid chamber decreases in accordance with the degree of decrease in the current value. Therefore, the pressure in the main liquid chamber is maintained at the vapor pressure or higher. It is possible to avoid the pressure of the main liquid chamber from being equal to or lower than the vapor pressure. Accordingly, even when a large vibration is input from the vibration source, it is possible to suppress the occurrence of cavitation in the main liquid chamber, and it is possible to suppress the generation of abnormal noise. In addition, in the region where the current value is positive, the power consumption can be reduced by reducing the current value, and in the region where the current value is positive, the current value is not reduced. It is possible to improve the function of vibration isolation. Therefore, according to the above configuration, cavitation can be suppressed without increasing the power consumption and without reducing the function of vibration isolation.

  According to the present invention, by reducing the current value of the current to the actuator, the displacement of the movable member by the actuator becomes smaller according to the degree of decrease in the current value. As the displacement of the movable member decreases, the pressure fluctuation in the main liquid chamber decreases according to the degree of decrease in the current value. Therefore, the pressure in the main liquid chamber is reduced to a predetermined pressure (vapor pressure) at which cavitation can occur. ) Can be maintained above, and the pressure of the main liquid chamber can be avoided from becoming a pressure equal to or lower than the vapor pressure. Accordingly, even when a large vibration is input from the vibration source, it is possible to suppress the occurrence of cavitation in the main liquid chamber, and it is possible to suppress the generation of abnormal noise. Further, since the amount of current to the actuator becomes small, power consumption can be suppressed. Therefore, according to the above configuration, cavitation can be suppressed without increasing power consumption.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, an active vibration isolator (active control engine mount) according to this embodiment includes a liquid-filled engine mount main body 10 and a mount control apparatus 100 that controls the operation of the engine mount main body 10. And. In the active vibration isolator, the vibration isolating characteristics of the engine mount body 10 can be changed by the control by the mount controller 100.

[Engine mount body]
Next, the basic configuration of the liquid-filled engine mount body 10 provided in the active vibration isolator will be briefly described. The engine mount body 10 is disposed between an engine stay and a vehicle body stay, and is used in a state where the upper end is fastened to the engine side and the lower end is fastened to the vehicle body side with bolts.

  As shown in FIG. 1, the engine mount body 10 includes a body rubber 11, a diaphragm 12, liquid chambers 21 and 22 in which an incompressible liquid (for example, ethylene glycol, silicon oil, etc.) is sealed, The actuator unit 30 having a solenoid coil 31 and a movable member (vibrating member) 23 for changing the volume of the main liquid chamber 21 are provided. In the main body rubber 11 provided in the upper part of the engine mount main body 10, the lower part of the mounting bracket 13 in which the screw hole 13a is formed is embedded. Bolts for fastening with the engine are screwed into the screw holes 13a. A plurality of brackets 14 to which bolts 14 a for fastening to the vehicle body are attached are provided at the lower part of the engine mount body 10.

  The liquid chambers 21 and 22 are partitioned by the movable member 23 and the like. That is, the main liquid chamber 21 is provided on the main rubber 11 side and the sub liquid chamber 22 is provided on the diaphragm 12 side with the movable member 23 and the like interposed therebetween. The main liquid chamber 21 and the sub liquid chamber 22 communicate with each other via a restriction passage (orifice) 24. When the liquid moves between the liquid chambers 21 and 22 through the orifice 24, a vibration damping force is generated by the resistance when the liquid passes through the orifice 24, so that transmission of vibration from the vibration source is suppressed. ing.

  The actuator unit 30 is for moving the movable member 23 up and down, and includes a solenoid coil 31, a plunger member 32, a drive shaft member 33, and the like. The lower end of the drive shaft member 33 is fixed to the plunger member 32, and the fixing member 35 is attached to the upper end of the drive shaft member 33. The fixing member 35 is embedded in the movable member 23 made of an elastic body such as rubber. In addition, an introduction portion 36 for introducing a wiring or the like for sending a current to the solenoid coil 31 is provided below the engine mount body 10.

  Then, by applying an alternating current to the solenoid coil 31 of the actuator unit 30, the plunger member 32 and the drive shaft member 33 are reciprocated up and down (in the direction along the axis), and accordingly, the movable member 23 is moved up and down. Are reciprocated (vibrated). The volume of the main liquid chamber 21 is changed by the movement of the movable member 23. The movement of the plunger member 32 and the drive shaft member 33 is restricted by the engagement of the groove (concave portion) 32a formed in the plunger member 32 and the locking claw (convex portion) 37 fitted in the groove 32a. Is done. Therefore, the distance in which the plunger member 32 and the drive shaft member 33 can move in the vertical direction is set by the groove width of the groove 32 a and the width of the locking claw 37.

  Thus, the volume of the main liquid chamber 21 is changed by energizing the solenoid coil 31. Specifically, when the current value of the current supplied to the solenoid coil 31 is positive, the movable member 23 is moved upward. Specifically, the movable member 23 is elastically deformed and its central portion is lifted upward. The volume of the main liquid chamber 21 is reduced. As a result, the pressure in the main liquid chamber 21 changes to the positive pressure side. On the other hand, when the current value of the current supplied to the solenoid coil 31 is negative, the movable member 23 is moved downward. Specifically, the movable member 23 is elastically deformed and its central portion is pulled downward, The volume of the liquid chamber 21 is increased. Thereby, the pressure of the main liquid chamber 21 fluctuates to the negative pressure side.

[Mount controller]
Next, the mount control device 100 provided in the active vibration isolator will be described.

  The mount control device 100 is generally configured as a known ECU (electronic control unit). Specifically, as shown in FIG. 2, the mount control apparatus 100 includes a central processing unit (CPU) 101, a read only memory (ROM) 102, a random access memory (RAM) 103, a backup RAM 104, and an input. The interface 105 and the output interface 106 are connected to each other via a bidirectional bus 107.

  The CPU 101 executes arithmetic processing based on an appropriate control program or control map stored in the ROM 102. The ROM 102 stores at least a control program and a control map related to image stabilization control by the engine mount body 10. The RAM 103 is a memory that temporarily stores calculation results in the CPU 101, data input from various sensors, and the like. The backup RAM 104 is a non-volatile memory that stores various data to be saved.

  The input interface 105 is connected to various sensors necessary for vibration control by the engine mount body 10. The output interface 106 is connected to the actuator unit 30 of the engine mount body 10. Examples of various sensors connected to the input interface 105 include a pressure sensor 111, a starter relay 112, a suspension stroke sensor 113, a throttle position sensor 114, an acceleration sensor 115, a flow velocity sensor 116, a temperature sensor 117, and the like.

  The mount control device 100 controls the drive of the actuator unit 30 of the engine mount body 10 according to the vibration state input from the vibration source to the engine mount body 10 to change the vibration isolation characteristics of the engine mount body 10. Specifically, the mount control device 100 determines a vibration state input from the vibration source to the engine mount body 10 based on detection outputs from various sensors, and the actuator unit of the engine mount body 10 according to the vibration state. The energization control (current control) for 30 solenoid coils 31 is performed. The vibration source may be on the engine side or the vehicle body side.

  The current control of the solenoid coil 31 of the actuator unit 30 by the mount control device 100 is performed based on, for example, a control map (a current map showing a current waveform (for example, a sine wave)) as shown in FIG. And by this electric current control, the movable member 23 is moved up and down to change the volume of the main liquid chamber 21, thereby interrupting the transmission of vibrations (normal vibration control).

  Here, as the amplitude of the current waveform in FIG. 3 is increased, the displacement amount of the movable member 23 is increased, and the change amount of the volume of the main liquid chamber 21 is increased. The amplitude of the current waveform is set according to the vibration state input to the engine mount body 10 from the vibration source. In this case, the amplitude of the current waveform is set to be larger as the vibration (vibration amplitude) input from the vibration source to the engine mount body 10 is larger. However, in the case of a large input in which the amplitude of the current waveform becomes large, cavitation may occur when the pressure of the main liquid chamber 21 fluctuates to the negative pressure side. Therefore, in this embodiment, control for suppressing the occurrence of cavitation as described below is performed.

[Characteristics of Embodiment]
In this embodiment, in the active vibration isolator, the mount control device 100 performs cavitation generation suppression control of the engine mount main body 10 in addition to the normal vibration isolation control by the engine mount main body 10 described above. The cavitation occurrence suppression control of the engine mount body 10 will be described with reference to the flowchart of FIG. The routine shown in FIG. 4 is a part of the main routine related to the image stabilization control executed by the mount control device 100, and is repeated at regular intervals.

  First, in step ST1, the mount control apparatus 100 determines whether or not the engine mount body 10 is in a state where cavitation can occur. This determination can be made based on the detection output from the pressure sensor 111. The pressure sensor 111 detects the pressure in the main liquid chamber 21 of the engine mount body 10. In this case, for example, the pressure sensor 111 can be configured to detect the pressure in the vicinity of the orifice 24 that connects the main liquid chamber 21 and the sub liquid chamber 22. Based on the detection output of the pressure sensor 111, it is determined whether or not the pressure of the main liquid chamber 21 of the engine mount body 10 is a predetermined pressure (pressure equal to or lower than the vapor pressure) that can generate cavitation.

  When the pressure of the main liquid chamber 21 is a pressure that can generate cavitation, that is, when the pressure is equal to or lower than the vapor pressure, the engine mount body 10 is in a state that can generate cavitation. It is determined that there is, and the process proceeds to the next step ST2. On the other hand, when the pressure of the main liquid chamber 21 is not a pressure capable of generating cavitation, that is, when the pressure is not lower than the vapor pressure, the engine mount main body 10 is in a state capable of generating cavitation. This routine is terminated.

  Here, in step ST1, it is also possible to determine whether or not the engine mount main body 10 is in a state where cavitation can occur, based on the output from other than the pressure sensor 111. In this case, the engine mount body 10 generates cavitation by determining whether the vibration input from the vibration source to the engine mount body 10 is a large input based on the outputs from the various sensors 112 to 117. It is possible to determine whether or not the state is obtained. Specifically, vibration input from the vibration source to the engine mount body 10 based on the outputs of the starter relay 112, the suspension stroke sensor 113, the throttle position sensor 114, the acceleration sensor 115, the flow velocity sensor 116, the temperature sensor 117, and the like described above. Is determined as a large input.

  The starter relay 112 outputs a starter on signal during cranking for driving the starter motor to start the engine. Based on the starter-on signal from the starter relay 112, it is possible to determine whether or not the vibration input from the vibration source to the engine mount body 10 is a large input. When there is a starter-on signal, it is determined that the vibration is a large input. On the other hand, when there is no starter-on signal, it is determined that the vibration is not a large input. In this way, the output from the starter relay 112 is used as a determination factor as to whether or not the vibration input to the engine mount body 10 is a large input. The engine is driven during cranking to start the engine by driving the starter motor. This is because there is a high possibility that a large input is transmitted to the mount body 10.

  The suspension stroke sensor 113 detects the amount of extension (or amount of contraction) of the suspension that supports each wheel of the vehicle. In this case, for example, a suspension stroke sensor 113 may be provided for each wheel to detect the amount of suspension extension of each wheel. Based on the detection output from the suspension stroke sensor 113, it is possible to determine whether or not the vibration input from the vibration source to the engine mount body 10 is a large input. This determination can be made, for example, by examining whether or not the suspension extension amount is equal to or greater than a predetermined value based on the detection output from the suspension stroke sensor 113.

  Then, when the extension amount of the suspension is greater than or equal to a predetermined value, it is determined that the vibration is a large input. On the other hand, when the elongation amount is not equal to or greater than the predetermined value, it is determined that the vibration is not a large input. As described above, the detection output from the suspension stroke sensor 113 is used as a determination factor as to whether or not the vibration input to the engine mount main body 10 is a large input when the extension amount of the suspension is a predetermined value or more. This is because there is a high possibility that a large input is transmitted to the engine mount body 10 in this case. The predetermined value is a threshold for determining whether or not the vibration input to the engine mount body 10 is a large input, and is stored in the ROM 102 in advance.

  The throttle position sensor 114 detects the opening of the throttle valve. Based on the detection output from the throttle position sensor 114, it is possible to determine whether or not the vibration input from the vibration source to the engine mount body 10 is a large input. This determination can be made, for example, by examining whether or not the throttle valve opening is greater than or equal to a predetermined value based on the detection output from the throttle position sensor 114.

  If the opening of the throttle valve is greater than or equal to a predetermined value, it is determined that the vibration is a large input. On the other hand, if the opening is not greater than or equal to the predetermined value, it is determined that the vibration is not a large input. . As described above, the detection output from the throttle position sensor 114 is used as a determination factor as to whether or not the vibration input to the engine mount body 10 is a large input when the throttle valve opening is greater than or equal to a predetermined value. This is because the output torque of the engine increases, and there is a high possibility that a large input will be transmitted to the engine mount body 10. The predetermined value is a threshold for determining whether or not the vibration input to the engine mount body 10 is a large input, and is stored in the ROM 102 in advance.

  The acceleration sensor 115 detects an input acceleration of vibration transmitted to the engine mount body 10. Based on the detection output from the acceleration sensor 115, it is possible to determine whether or not the vibration input from the vibration source to the engine mount body 10 is a large input. This determination can be made, for example, by examining whether the input acceleration of vibration transmitted to the engine mount body 10 is greater than or equal to a predetermined value based on the detection output from the acceleration sensor 115.

  If the input acceleration of the vibration transmitted to the engine mount body 10 is greater than or equal to a predetermined value, it is determined that the vibration is a large input, whereas if the acceleration is not greater than the predetermined value, the vibration is a large input. It is judged that it is not. As described above, the detection output from the acceleration sensor 115 is used as a determination factor as to whether or not the vibration input to the engine mount body 10 is a large input when the input acceleration of the vibration is a predetermined value or more. This is because there is a high possibility that the vibration is a large input. The predetermined value is a threshold for determining whether or not the vibration input to the engine mount body 10 is a large input, and is stored in the ROM 102 in advance.

  The flow rate sensor 116 detects the flow rate of the liquid passing through the orifice 24 that communicates the main liquid chamber 21 and the sub liquid chamber 22. Based on the detection output from the flow velocity sensor 116, it is possible to determine whether or not the vibration input from the vibration source to the engine mount body 10 is a large input. This determination can be made, for example, by examining whether the flow rate of the liquid passing through the orifice 24 is equal to or higher than a predetermined speed based on the detection output from the flow rate sensor 116.

  When the flow velocity of the liquid passing through the orifice 24 is equal to or higher than the predetermined speed, it is determined that the vibration is a large input. On the other hand, when the flow velocity is not equal to or higher than the predetermined speed, the vibration is determined not to be a large input. Is done. As described above, the detection output from the flow rate sensor 116 is used as a determination factor as to whether or not the vibration input to the engine mount body 10 is a large input. The flow rate of the liquid passing through the orifice 24 is greater than or equal to a predetermined speed. This is because there is a high possibility that a large input has been transmitted to the engine mount body 10. The predetermined speed is a threshold for determining whether or not the vibration input to the engine mount main body 10 is a large input, and is stored in the ROM 102 in advance.

  The temperature sensor 117 detects the temperature of the liquid sealed in the main liquid chamber 21. Based on the detection output from the temperature sensor 117, it is possible to determine whether or not the vibration input from the vibration source to the engine mount body 10 is a large input. This determination can be made, for example, by examining whether or not the temperature of the liquid sealed in the main liquid chamber 21 is equal to or higher than a predetermined temperature based on the detection output from the temperature sensor 117.

  When the temperature of the liquid sealed in the main liquid chamber 21 is equal to or higher than a predetermined temperature, the vibration is determined to be a large input. On the other hand, when the temperature is not equal to or higher than the predetermined temperature, the vibration is not a large input. Judged not. As described above, the detection output from the temperature sensor 117 is used as a determination factor as to whether or not the vibration input to the engine mount main body 10 is a large input. The temperature of the liquid sealed in the main liquid chamber 21 is predetermined. This is because when the temperature is higher than the temperature, there is a high possibility that a large input is transmitted to the engine mount body 10. The predetermined temperature is a threshold for determining whether or not the vibration input to the engine mount body 10 is a large input, and is stored in the ROM 102 in advance.

  In this embodiment, the engine mount body 10 generates cavitation if at least one of the above six cases in which the vibration input to the engine mount body 10 is determined to be a large input is applicable. It is determined that the state is obtained, and the process proceeds to the next step ST2. On the other hand, if none of the above six cases is applicable, it is determined that the engine mount body 10 is not in a state where cavitation can occur, and this routine is terminated.

  Next, the mount control device 100 executes a cavitation generation suppression process in step ST2. In this cavitation generation suppressing process, the current supplied to the solenoid coil 31 of the actuator unit 30 is controlled, and the pressure of the main liquid chamber 21 of the engine mount body 10 becomes a pressure at which cavitation can occur (pressure below the vapor pressure). This is a process to avoid this. In this case, for example, a predetermined calculation process or the like is performed to control the current supplied to the solenoid coil 31 of the actuator unit 30.

  Hereinafter, specific examples of the cavitation generation suppressing process executed by the mount control device 100 in the active vibration isolator will be described separately for the three cases of the first to third embodiments.

[First embodiment]
As illustrated in FIG. 5, the first embodiment is a control that increases the current value of the current supplied to the actuator unit 30 as a whole. This will be specifically described below.

The mount control device 100 executes a calculation process for shifting the current value of the current supplied to the solenoid coil 31 of the actuator unit 30 to the positive direction side as shown in FIG. 5, for example. This calculation process is a process of adding a predetermined shift amount α1 (α1> 0) to the current value of the current of the normal image stabilization control as shown in FIG. 3 (indicated by a broken line in FIG. 5), for example. . Therefore,
(Current value of this embodiment) = (Current value of normal image stabilization control) + α1
It becomes the relationship. As a result, the current waveform J1 of the current in this embodiment is shifted (translated) to the positive direction side by the shift amount α1 with respect to the current waveform J0 of the current (current before the shift process) of the normal image stabilization control. Waveform (sine wave).

  Thus, by raising the current value of the current supplied to the solenoid coil 31 of the actuator unit 30 as a whole, the center position of the displacement of the movable member 23 by the solenoid coil 31 corresponds to the shift amount α1 of the current value. Move upward (to the main liquid chamber 21 side). As the movable member 23 is displaced, the pressure in the main liquid chamber 21 rises as a whole as shown in FIG. In other words, the center of the pressure fluctuation in the main liquid chamber 21 due to the displacement of the movable member 23 (the center of the amplitude of the pressure fluctuation waveform P1) is shifted to the positive pressure side by the predetermined shift amount β1. FIG. 6 shows a waveform P1 of the pressure fluctuation in the main liquid chamber 21 with a solid line, and the shift amount β1 is a value corresponding to the shift amount α1 of the current value. The broken line in FIG. 6 indicates the waveform of the pressure fluctuation in the main liquid chamber 21 due to the current before the shift process indicated by the broken line in FIG.

  Here, the shift amount α1 of the current value of the current to the solenoid coil 31 of the actuator unit 30 is such that the minimum pressure (P1min in FIG. 6) in the main liquid chamber 21 after the shift process by the shift amount α1 exceeds the vapor pressure P0. It is set to such a value. In other words, the shift amount α1 of the current value is greater than the difference between the minimum pressure (P1min ′ in FIG. 6) of the main liquid chamber 21 before the shift process and the vapor pressure P0, which corresponds to the shift amount α1. It is set to a value that increases. Such a shift amount α1 of the current value can be set based on a relationship as shown in FIG. 7, for example. The horizontal axis of FIG. 7 represents the amplitude of the current waveform J0 (dashed line in FIG. 5) J0 of the current before the shift processing. The larger the amplitude of the current waveform J0, the larger the current value shift amount α1 is set. It has become so. It should be noted that the current value shift amount α1 is set based on the relationship shown in FIG. 7, as described above, in this embodiment, the amplitude of vibration input from the vibration source to the engine mount body 10 is determined. This is because the larger the amplitude, the larger the amplitude of the current waveform J0 of the current of the normal vibration control is.

  According to the first embodiment, the pressure of the main liquid chamber 21 is shifted to the positive pressure side by the shift amount β1 by the shift process of the current value of the current supplied to the actuator unit 30. Even if this occurs, the pressure in the main liquid chamber 21 can always be kept at the vapor pressure P0 or higher, and the pressure in the main liquid chamber 21 can be prevented from becoming a pressure below the vapor pressure P0. Thereby, even when a large vibration is input to the engine mount body 10 from the vibration source, the generation of cavitation in the engine mount body 10 can be suppressed, and the generation of abnormal noise associated therewith can be suppressed.

[Second Embodiment]
The second embodiment is an improvement of the first embodiment, and as illustrated in FIG. 8, the control for reducing the current value of the current flowing to the actuator unit 30, that is, the amplitude of the current waveform of the current is changed. It is a control to decrease. This will be specifically described below.

The mount control apparatus 100 executes a calculation process for decreasing the current value of the current that is supplied to the solenoid coil 31 of the actuator unit 30 as shown in FIG. 8, for example. This calculation process is a process of multiplying the current value of the current of the normal image stabilization control as shown in FIG. 3 (shown by a broken line in FIG. 8) by a predetermined reduction degree α2 (α2 <1). . Therefore,
(Current value of this embodiment) = (Current value of normal image stabilization control) × α2
It becomes the relationship. As a result, the current waveform J2 of the current in this embodiment is a waveform (sine wave) in which the current value is reduced by the reduction degree α2 with respect to the current waveform J0 of the current of the normal vibration isolation control (current before the reduction process). It has become. That is, the amplitude of the current waveform J2 is smaller than the amplitude of the current waveform J0 by the reduction degree α2. Then, the current amount of the current in this embodiment becomes smaller by the reduction degree α2 than the current amount of the current of the image stabilization control.

  In this way, by reducing the current value (current amount) of the current flowing through the solenoid coil 31 of the actuator unit 30, the displacement of the movable member 23 by the solenoid coil 31 causes the current value decrease degree (current amount decrease degree). ) It becomes smaller according to α2. As the displacement of the movable member 23 decreases, the pressure in the main liquid chamber 21 decreases as shown in FIG. That is, the pressure fluctuation of the main liquid chamber 21 due to the displacement of the movable member 23 decreases according to the current value decrease degree α2. FIG. 9 shows a waveform P2 of the pressure fluctuation in the main liquid chamber 21 with a solid line, and the amplitude of the pressure fluctuation waveform P2 in the main liquid chamber 21 decreases according to the current value decrease degree α2. The broken line in FIG. 9 shows the waveform of the pressure fluctuation in the main liquid chamber 21 due to the current before the reduction process indicated by the broken line in FIG.

  Here, the reduction degree α2 of the current value of the current to the solenoid coil 31 of the actuator unit 30 is such that the minimum pressure (P2min in FIG. 9) after the reduction process by the reduction degree α2 exceeds the vapor pressure P0. It is set to such a value. In other words, the reduction degree α2 of the current value is set to a value that is smaller than the ratio (P0 / P2min ′) between the lowest pressure (P2min ′ in FIG. 9) of the main liquid chamber 21 before the reduction process and the vapor pressure P0. Is set. Such a decrease degree α2 of the current value can be set based on a relationship as shown in FIG. 10, for example. The horizontal axis of FIG. 10 represents the amplitude of the current waveform P0 (dashed line in FIG. 8) P0 of the current before the reduction process, and the current value decrease degree α2 is set to a smaller value as the amplitude of the current waveform J0 increases. It has become so. Note that the current value reduction degree α2 is set based on the relationship as shown in FIG. 10, as described above, in this embodiment, the amplitude of vibration input from the vibration source to the engine mount body 10 is set. This is because the larger the amplitude, the larger the amplitude of the current waveform J0 of the current of the normal vibration control is.

  According to the second embodiment, the following effects can be obtained in addition to the cavitation suppressing effect described in the first embodiment. That is, in the second embodiment, since the current amount of the current is reduced by the process of reducing the current value of the current flowing through the actuator unit 30, the first control for shifting the current value to the positive direction as a whole is performed. Compared to the embodiment, power consumption can be suppressed. Therefore, according to the second embodiment, cavitation can be suppressed without increasing the power consumption.

[Third embodiment]
The third embodiment is an improvement over the first and second embodiments, and is a control that decreases only when the current value of the current flowing through the actuator unit 30 is negative, as illustrated in FIG. This will be specifically described below.

  The mount control apparatus 100 executes a calculation process for reducing the current value of the current that is supplied to the solenoid coil 31 of the actuator unit 30 as shown in FIG. 11, for example. In this embodiment, prior to the decrease process, it is determined whether or not the current value is negative. If the current value is positive, the decrease process is not performed, whereas the current value is negative. The same reduction process as in the second embodiment is performed. That is, when the current value is negative, for example, a predetermined decrease degree α3 (α3 <1) with respect to the current value of the current of the normal image stabilization control as shown in FIG. 3 (shown by a broken line in FIG. 11). ) Only to multiply.

Therefore, if the current value is positive,
(Current value of this embodiment) = (Current value of normal image stabilization control)
It becomes the relationship. If the current value is negative,
(Current value of this embodiment) = (Current value of normal image stabilization control) × α3
It becomes the relationship. As a result, the current waveform J3 of the current in this embodiment is the same waveform in the region where the current value is positive with respect to the current waveform J0 of the current of the normal image stabilization control (current before the reduction process). In the region where the value is negative, the waveform is obtained by reducing the current value by the reduction degree α3. In other words, the amplitude of the current waveform J3 of the current is reduced according to the decrease degree α3 only in the region where the current value is negative.

  As described above, since the current value of the current supplied to the solenoid coil 31 of the actuator unit 30 is decreased when the current value is negative, the movable member 23 corresponding to the positive region of the displacement of the movable member 23 by the solenoid coil 31 is movable. Although the displacement of the member 23 does not change, the displacement of the movable member 23 corresponding to the region where the current value is negative decreases according to the current value decrease degree α3. As the displacement of the movable member 23 decreases, the pressure in the main liquid chamber 21 decreases as shown in FIG. That is, only the pressure fluctuation on the negative pressure side of the main liquid chamber 21 decreases according to the current value decrease degree α3. FIG. 12 shows a waveform P3 of the pressure fluctuation in the main liquid chamber 21 with a solid line, and the amplitude of the pressure fluctuation waveform P3 in the main liquid chamber 21 decreases only on the negative pressure side in accordance with the current value decrease degree α3. In addition, the broken line of FIG. 12 has shown the waveform of the pressure fluctuation of the main liquid chamber 21 by the electric current before the reduction process shown with the broken line of FIG.

  Here, the current value decrease degree α3 to the solenoid coil 31 of the actuator unit 30 can be set in the same manner as the current value decrease degree α2 in the second embodiment. . Specifically, the current value reduction degree α3 is set to a value such that the minimum pressure (P3min in FIG. 12) of the main liquid chamber 21 after the reduction process based on the reduction degree α3 exceeds the vapor pressure P0. In other words, the decrease degree α3 of the current value is set to a value that is smaller than the ratio (P0 / P3min ′) between the lowest pressure (P3min ′ in FIG. 12) of the main liquid chamber 21 before the reduction process and the vapor pressure P0. Is set. Such a current value reduction degree α3 can be set based on the same relationship (see FIG. 10) as the current value reduction degree α2 of the second embodiment.

  According to the third embodiment, the following effects can be obtained in addition to the cavitation suppressing effect described in the first embodiment. That is, in the third embodiment, since the current value is reduced only in a region where the current value of the current flowing through the actuator unit 30 is negative, the first embodiment of the control for shifting the current value to the positive side as a whole. Compared to the example, power consumption can be reduced. In addition, even in the region where the current value is positive, the function of vibration isolation, which is the original function of the active vibration isolator, can be improved compared to the second embodiment in which the current value is reduced. Therefore, according to the third embodiment, it is possible to suppress cavitation without increasing power consumption and without reducing the function of vibration isolation, which is the original function of the active vibration isolator.

[Modification]
The embodiment of the present invention has been described above. However, the embodiment shown here is an example and can be variously modified. An example is given below.

  (1) The control maps (current maps) shown in FIGS. 3, 5, 8, and 11 and the relationships shown in FIGS. 7 and 10 are examples, and other control maps and relationships may be used. Good.

  (2) In each of the above embodiments, the case where the current supplied to the solenoid coil 31 of the actuator unit 30 is controlled by the predetermined calculation process by the mount control device 100 has been described. The current supplied to the solenoid coil 31 of the unit 30 may be controlled. Moreover, you may control the electric current supplied to the solenoid coil 31 of the actuator part 30 by feedback control instead of map control.

  (3) The configuration of the liquid-filled engine mount body 10 is an example, and other configurations may be used as long as the vibration control characteristics can be changed by the mount control device 100. For example, the shapes and locations of the liquid chambers 21 and 22, the orifice 24, the movable member 23, etc. are not particularly limited. A partition member such as a partition plate may be provided separately from the movable member 23, and the liquid chambers 21 and 22 may be partitioned by the partition member, or a plurality of orifices 24 having different attenuation characteristics may be provided. The member 23 may be a metal plate member.

  (4) It is not necessary to provide all the various sensors 111 to 117 for determining the vibration state input to the engine mount body 10 from the vibration source, as long as at least one of the various sensors 111 to 117 is provided. Good.

It is the schematic which shows the whole structure of the active vibration isolator which concerns on embodiment. It is a block diagram which shows schematic structure of the mount control apparatus with which an active vibration isolator is equipped. It is a map which shows the electric current waveform which supplies with electricity to the actuator in normal anti-vibration control of an active vibration isolator. It is a flowchart which shows the procedure of cavitation generation | occurrence | production suppression control of an active vibration isolator. It is a map which shows the electric current waveform which supplies with electricity to the actuator in 1st Example. It is a figure which shows the pressure fluctuation of the main liquid chamber accompanying the displacement of the movable member by the actuator of 1st Example. It is a figure which shows the relationship used for the setting of the shift amount of the electric current value which supplies with electricity to the actuator of 1st Example. It is a map which shows the electric current waveform which supplies with electricity to the actuator in 2nd Example. It is a figure which shows the pressure fluctuation of the main liquid chamber accompanying the displacement of the movable member by the actuator of 2nd Example. It is a figure which shows the relationship used for the setting of the reduction degree of the electric current value which supplies with electricity to the actuator of 2nd Example. It is a map which shows the electric current waveform which supplies with electricity to the actuator in 3rd Example. It is a figure which shows the pressure fluctuation of the main liquid chamber accompanying the displacement of the movable member by the actuator of 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine mount main body 11 Main body rubber | gum 12 Diaphragm 21 Main liquid chamber 22 Sub liquid chamber 23 Movable member 24 Orifice 30 Actuator part 31 Solenoid coil 100 Mount control apparatus 111 Pressure sensor

Claims (3)

A main liquid chamber filled with an incompressible liquid, a movable member for changing the volume of the main liquid chamber, an actuator for moving the movable member, and a vibration state input from a vibration source are determined. The vibration-proof characteristic can be changed by changing the volume of the main liquid chamber by moving the movable member by driving the actuator by energization according to the vibration state input from the vibration source. In the active vibration isolator configured in
When the vibration input from the vibration source is a large input, the current value of the current supplied to the actuator is reduced as compared with the case where the vibration input from the vibration source is not a large input. Active vibration isolator. The sensor that detects the vibration state input from the vibration source is a pressure sensor that detects the pressure of the main liquid chamber,
2. The vibration input from the vibration source is determined to be a large input when the pressure of the main liquid chamber by the pressure sensor is a pressure capable of generating cavitation. The active vibration isolator as described.   3. The active vibration isolator according to claim 1, wherein the current control to the actuator is performed only when the current value is negative.

Images