JP2016217487A - Vibration reduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration reduction device capable of reducing the total inductance of an actuator coil, while maintaining thrust generated in an actuator.SOLUTION: A vibration reduction device includes a rod 200 connecting between an engine and a vehicle body, an actuator 10 causing an inertial mass 11 supported on the rod to reciprocatively moving in a predetermined direction in the rod 200, and control means of controlling the actuator 10 to generate force proportional to speed of displacement of the rod 200 in the predetermined direction. The actuator 10 has a plurality of coils 14, 15 mutually independent each other. The ratio of the number of turns for the coils 14, 15 satisfies any one of the formula (1) and the formula (2), where m is a natural number of two or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration reducing device.

  A first bush attached to the engine, a second bush attached to the vehicle body side, a torque rod connecting the pair of insulators, an inertia mass supported by the rod, and the inertia mass reciprocating in the axial direction of the rod In a vibration reduction apparatus including an actuator to be moved and a control means for controlling the actuator to generate a force proportional to the speed of the axial displacement of the rod, the actuator includes a core and a coil wound around the core. And a vibration reduction device that performs voltage control by applying a voltage to the coil by a voltage amplification circuit is disclosed (Patent Document 1).

JP 2011-12757 A

  However, the coil provided in the above-described vibration reduction device is configured by a single coil in which a coiled wire is wound around a rectangular tube-shaped core. Therefore, there is a problem that the total inductance of the actuator coil cannot be reduced while maintaining the thrust generated in the actuator.

  The problem to be solved by the present invention is to provide a vibration reducing device capable of reducing the total inductance of the actuator coil while maintaining the thrust generated by the actuator.

In the present invention, a plurality of coils independent of each other are provided in an actuator, and the turn ratios (a ₁ , a ₂ ,..., A _m ) of the plurality of coils are expressed by the following formulas (1) and (2). The above-described problem is solved by configuring so as to satisfy either one of them.

  According to the present invention, when the number of turns of a plurality of coils is reduced in order to reduce the inductance, the total thrust of the actuator is the sum of the thrusts generated by the electromagnetic induction of the individual coils. The size of can be maintained. As a result, there is an effect that the total inductance can be reduced while maintaining the magnitude of the thrust of the actuator generated by the electromagnetic induction of the entire coil.

FIG. 1 is a block diagram of a vibration reducing apparatus according to this embodiment. FIG. 2 is a block diagram of the actuator, the controller, and the amplifier shown in FIG. FIG. 3 shows an electrical equivalent circuit of the actuator shown in FIG. FIG. 4 is a block diagram of an actuator, a controller, and an amplifier in the vibration reducing device according to the comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of a vibration reducing apparatus according to this embodiment. The vibration reducing device according to the present embodiment is a device for suppressing the vibration of the rod. As shown in FIG. 1, the vibration reducing device includes a torque rod 200, an actuator 10, and a controller 20. The actuator 10 suppresses vibration of the torque rod 200 by moving an inertial mass described later relative to the torque rod 200.

  The torque rod 200 is a rod connected between the vehicle body and the engine, and has a structure that reduces vibration transmitted from the engine to the vehicle body. The torque rod 200 includes a rod shaft portion 201 and rod end portions 202 and 203. The rod shaft portion 201 is formed in a cylindrical shape, and the direction from the center point of the cylindrical rod end portion 202 toward the center point of the cylindrical rod end portion 203 is an axis. A cavity for attaching the actuator 10 is formed in the rod shaft portion 201.

  The rod end portion 202 is provided at one end of the rod shaft portion 201. The rod end portion 202 is formed in a cylindrical shape and includes an outer cylinder 202a, an inner cylinder 202b, and an elastic body 202c. The outer cylinder 202a and the inner cylinder 202b are formed in a cylindrical shape. The elastic body 202c is interposed between the outer cylinder 202a and the inner cylinder 202b. The elastic body 202c is made of, for example, elastic rubber and has a damping property. The cylindrical hole of the inner cylinder 202b becomes a bolt insertion hole. The rod end 202 is attached to the engine with a bolt.

  The rod end 203 is provided at the other end of the rod shaft 201. The basic structure of the rod end 203 is the same as that of the rod end 202, and includes an outer cylinder 203a, an inner cylinder 203b, and an elastic body 203c. The rod end 203 is attached to the vehicle body with a bolt.

  In a state where the actuator 10 is attached to the torque rod 200, the torque rod 200 is attached between the engine and the vehicle body. The vibration of the engine is mainly transmitted along the axis of the rod shaft portion 201. At this time, the actuator 10 moves the inertial mass 11 relative to the torque rod 200. The relative movement direction is a direction along the axis of the rod shaft portion 201. Thereby, the vibration of the torque rod 200 is suppressed.

  Further, in order to efficiently suppress engine bending and torsional resonance vibration (hereinafter referred to as engine elastic resonance vibration), the torque rod 200 has a resonance frequency (hereinafter referred to as rod) in a direction along the axis of the rod shaft portion 201. (Referred to as resonance frequency).

  The engine elastic resonance frequency is a resonance frequency of engine elastic resonance vibration, and is about 280 to 350 Hz in the case of a general vehicle engine. On the other hand, the rod resonance frequency is a rigid resonance frequency determined by the characteristics of the torque rod 200 and is determined by the mass of the rod shaft portion 201 and the rod end portions 202 and 203. The rod resonance frequency also depends on the characteristics of the elastic bodies 202c and 203c.

  Therefore, in this embodiment, the characteristics of the elastic bodies 202c and 203c, the mass of the rod shaft portion 201 and the rod end portions 202 and 203, rigidity, and the like are defined so that the rod resonance frequency is lower than the engine elastic resonance frequency. Yes. Thereby, in the torque rod 200 that supports the engine torque, vibration in the axial direction of the rod shaft portion 201 can be suppressed, and noise in the passenger compartment during acceleration of the vehicle can be reduced.

  Next, the configuration of the actuator 10 will be described. The actuator 10 includes an inertia mass 11, a leaf spring 12, a core 13, coils 14 and 15, a magnet 16, and a shaft 17. The configuration of the actuator 10 is not limited to the configuration shown in FIG. 1, and includes other configurations such as a bobbin.

  The inertia mass 11 corresponds to an outer member (movable element) of the actuator 10 and is interposed via a leaf spring 12 so as to reciprocate relative to the inner member in the front-rear direction (thrust direction: y direction in FIG. 1). Supported by the inner member. The moving direction of the inertia mass is the same as the axial direction of the shaft 17 (y direction in FIG. 1). The inertial mass 11 has a laminated steel plate or the like.

  The leaf springs 12 are arranged between the magnet 16 and the inertial mass 11 so as to have a predetermined interval in the direction perpendicular to the movement axis direction of the inertial mass 11 (the x direction in FIG. 1) and have the same axis. The inner member and the inertial mass 11 are connected.

  The core 13, the coils 14 and 15, and the magnet 16 correspond to the inner member. The core 13 is composed of a plurality of plate-shaped laminated steel plates that serve as inner cores. An insertion hole for inserting the shaft 17 is provided at the center of the plurality of laminated steel plates. The core 13 is covered with a bobbin (not shown).

  The coils 14 and 15 are wound around the core 13 via a bobbin. The coils 14 and 15 are coils for generating a magnetic field by energization to reciprocate the inertial mass 11, and are configured as independent coils. The coil 14 and the coil 15 are disposed at a target position with respect to the central axis of the shaft 17 (axis center along the y direction in the figure). The center line (line along the x direction) of the coil surface (yz plane in FIG. 1) of the coil 14 and the center line (line along the x direction) of the coil surface (yz plane in FIG. 1) of the coil 14 are the same. It is. Further, the direction along the central axis of the coils 14 and 15 is a direction perpendicular to the axis of the shaft 17. In addition, the coils 14 and 15 are configured so that the ratio of the number of turns of each coil (winding ratio) satisfies a condition described later.

  The magnet 16 is supported by the bobbin with a predetermined distance from the inertial mass 11. The shaft 17 is a member for supporting the actuator 10 accommodated in the housing of the rod shaft portion 201 within the housing of the rod shaft portion 201 and is formed in a cylindrical shape. The shaft 17 fixes the core 13 with an adhesive or the like while being inserted into the insertion hole of the core 13. The end portion of the shaft 17 is fixed to the torque rod 200 with, for example, a bolt.

  The controller 20 controls the actuator 10 so as to generate a force proportional to the axial displacement of the torque rod 200.

  Next, the configuration of the coils 14 and 15 and the connection form between the coils 14 and 15 and the controller will be described with reference to FIG. FIG. 2 is a block diagram of the actuator 10, the controller 20, and the amplifier 21.

  The coil 14 includes a coil 14a and a coil 14b, and the coil 15 includes a coil 15a and a coil 15b. The coil 14a is disposed closer to the shaft 17 than the coil 15a, in other words, inside the coil 15a. The coil 14b is disposed closer to the shaft 17 than the coil 15b, in other words, inside the coil 15b. In addition, the coil 14a and the coil 14b are disposed at the target axis and the central axis of the shaft 17. The coil 15a and the coil 15b are disposed at the center axis of the shaft 17 and the target position.

  The coil 14a is wound around a bobbin covering the core 13, and the coil 15a is wound around the coil 14a at a position outside the coil 14a. The coil 14b is wound around a bobbin that covers the core 13, and the coil 15b is wound around the coil 14b at a position outside the coil 14b. The coil 14 and the coil 15 are connected in parallel. The coil 14a and the coil 14b are connected in series, and the coil 15a and the coil 15b are connected in series.

  The controller 20 controls energization of the coils 14 and 15 so that current flows through the coils 14 and 15 to reciprocate the inertial mass 11. When the inertial mass 11 is driven, a current from a power source (not shown) such as a battery is passed through the coils 14 and 15. Further, the controller 20 measures the counter electromotive force generated in the coil 15 in a state where the output current from the power source is supplied only to the coil 14. The controller 20 incorporates a measurement circuit that measures the counter electromotive force from the output signal (analog signal) of the coil 15. And the electric current by the counter electromotive force which generate | occur | produced in the coil 15 flows into the measurement circuit incorporated in the controller 20, and the controller 20 measures the counter electromotive force of the coil 15 by detecting the electric current which flows into a measurement circuit. That is, in this embodiment, the coil 15 can be used as a drive coil for generating the thrust of the actuator 10 and can also be used as a search coil for detecting the state of the actuator 10.

  Here, the principle which can use the coil 15 as a search coil is demonstrated using FIG. FIG. 3 shows an electrical equivalent circuit of the actuator 10. Each symbol in FIG. 3 indicates the resistance r of the shunt resistor connected to the coil 14, the counter electromotive voltage E generated by the actuator 10, the input voltage Vs to the actuator 10, the voltage Vc applied to the actuator 10, the voltage Vr between shunt resistors, The current Ic flowing through the actuator 10 and the impedance Zc of the coil 14 are shown.

The back electromotive force E (t) and the relative speed dx _rel (t) / dt of the coil 14 with respect to the inertial mass have the following relationship (3) when the back electromotive force constant K _b is used. The relative speed dx _rel (t) / dt of the coil 14 with respect to the inertia mass corresponds to the relative speed of the actuator 10 with respect to the structure to be controlled. X _rel (t) indicates the displacement of the coil 14 with respect to the inertial mass.

Since the back electromotive force constant K _b is known in the above formula (3), the relative speed dx _rel (t) / dt can be detected by measuring the back electromotive force. Therefore, in the present embodiment, the coil 15 is caused to function as a dedicated coil (search coil) for measuring the counter electromotive force. The vibration reducing apparatus according to this embodiment controls energization to the coil 14 based on the back electromotive force measured using the coil 15.

Hereinafter, control of the controller 20 when the coil 15 is used as a search coil will be described. In order to measure the state quantity of the actuator 10 at a predetermined timing, the controller 20 changes from a current path that functions the coils 14 and 15 as a drive coil to a current path that measures the counter electromotive force using the coil 15. The current is passed through only the coil 14 by switching. Then, the controller 20 measures the back electromotive force of the coil 15 using a sensor included in the measurement circuit, and uses the arithmetic expression of the above expression (3) to calculate the state quantity (dx _rel (t) / dt of the actuator 10. ) Is calculated.

  Next, the controller 20 switches from the current path for measuring the back electromotive force to the current path for causing the coils 14 and 15 to function as a drive coil, and based on the measurement result of the back electromotive force, A control signal for controlling energization is generated, and the control signal is output to the amplifier 21.

  The amplifier 21 amplifies the input control signal and converts it into a rectangular wave signal by PWM control. The output side of the amplifier 21 is connected to the coils 14 and 15 by wiring. As the amplifier 21, a digital amplifier or an analog amplifier is used. When a digital amplifier is used as the amplifier 21, a small and power efficient amplifier can be used, so that power consumed in the vehicle can be suppressed. Further, when an analog amplifier is used as the amplifier 21, the S / N ratio of the control signal can be improved and the control robustness in the vibration reducing device can be improved.

  When a rectangular wave signal flows through the coil 14, a pseudo AC voltage is applied to the coil 14 while the coil 14 functions as an integrator. The inertial mass 11 is driven by the magnetic field generated by the coil 14 interlinking the magnet 16. At this time, the magnetic field generated by the coil 14 links the coil surface of the coil 15. Therefore, a counter electromotive force is generated in the coil 15. The controller 20 is electrically connected to the coil 15 from the outside of the actuator 10, and measures a signal output from the coil 15.

  Thereby, in the vibration suppression control of the actuator 10, when the inertial mass 11 is a control target, the control input from the controller 20 is input to the coils 14 and 15. The state of the controlled object can be grasped by measuring the relative movement (relative speed) of the inertial mass 11, but in this embodiment, the relative speed is estimated from the back electromotive force. A coil 15 for measuring the counter electromotive force is provided in the actuator 10. Therefore, by measuring the voltage output from the coil 15, the back electromotive force is directly measured, and the controller 20 can obtain the result of the controlled object. Thereby, the actuator 10 is controlled by feedback control.

  Next, the ratio of the number of turns of the coils 14 and 15 will be described with reference to FIGS. FIG. 4 is a block diagram of the actuator 10, the controller 20, and the amplifier 21 in the vibration reducing device according to the comparative example. Unlike the present embodiment, the actuator 10 according to the comparative example has a single coil 18 wound around a bobbin that covers a core.

ただし、μは透磁率を示し、Ａは磁路断面積を示し、Ｎはコイルのターン数、ｌ_ｇはコイルギャップを示す。 In the vibration reducing device according to the comparative example, the inductance (L) of the actuator coil and the thrust constant (Ka) of the actuator are expressed by the following equations (4) and (5).

However, mu denotes a magnetic permeability, A is shows a magnetic path cross-sectional area, N is the number of turns of the coil, l _g denotes a coil gap.

  In the vibration reducing apparatus according to the comparative example, it is necessary to reduce the inductance in order to reduce the error in the voltage drop calculation due to the impedance. As shown in Expression (4), in order to reduce the inductance, the number of turns (N) of the coil 18 may be reduced. However, as shown in Expression (5), if the number of turns (N) of the coil 18 is reduced, the thrust constant (Ka) is reduced, and the thrust of the actuator 10 is reduced.

  Further, in the vibration reducing device according to the comparative example, when the error in the voltage drop calculation due to the impedance is large, the control stability may be lowered. That is, when the relative speed is estimated from the back electromotive force generated in the coil and the vibration suppression control is performed, the impedance of the actuator when calculating the back electromotive force includes a differential term having an inductance component. For this reason, when the error is large, the estimation accuracy of the relative speed is lowered, and the stability of the control is also lowered.

ただし、ａ_１、ａ_２、・・・、ａ_ｍは、複数のコイル１４、１５の互いのターン数を正規化した値であり、ｍは２以上の自然数とする。言い替えると、ターン数の比（ａ_１、ａ_２、・・・、ａ_ｍ）は、基準とするターン数（例えば、比較例のターン数（Ｎ））で、複数のコイルのそれぞれのターン数を割った値である。 In this embodiment, in order to reduce the total inductance while maintaining the thrust of the actuator 10, the actuator coil is composed of a plurality of coils 14 and 15 independent of each other, and the number of turns of the plurality of coils 14 and 15 is set. The plurality of coils 14 and 15 are configured so that the ratio satisfies one of the following formula (6) and the following formula (7).

_{However, a 1, a 2, ···} , a m is a value number of turns to each other and normalized plurality of coils 14, 15, m is a natural number of 2 or more. In other words, the ratio of the number of turns (a ₁ , a ₂ ,..., A _m ) is the reference number of turns (for example, the number of turns (N) of the comparative example), and the number of turns of each of the plurality of coils. The value divided by.

For example, when the number of turns of the coil 18 of the vibration reduction device according to the comparative example is N, the number of turns (N ′) of the coils 14 and 15 of the vibration reduction device according to the present embodiment is N / 2. . At this time, the ratio (a ₁ , a ₂ ) of the number of turns of the coils 14 and 15 corresponds to 0.5. The inductance (L ′) of the coil 14 and the thrust constant (Ka ′) generated by electromagnetic induction of the coil 14 are expressed by the following equations (8) and (9), respectively.

  Similarly, the inductance (L ′) of the coil 15 and the thrust (Ka ′) generated by the electromagnetic induction of the coil 15 can also be expressed by equations (8) and (9).

  The total thrust generated by the actuator 10 is a total value of the thrust generated by the electromagnetic induction of the coil 14 and the thrust generated by the electromagnetic induction of the coil 15. Therefore, in this embodiment, the total thrust generated by the actuator 10 is the same as the thrust of the actuator according to the comparative example. That is, even if the number of turns of the coils 14 and 15 is reduced, the thrust generated in the actuator 10 can be maintained as long as the ratio of the number of turns satisfies the formula (6).

  Further, the inductance of the coil 14 and the inductance of the coil 15 are ¼ of the inductance of the coil 18 according to the comparative example. Therefore, the total inductance of the actuator coil in this embodiment is half that of the comparative example.

  That is, the vibration reduction device according to the present embodiment includes a plurality of coils 14 and 15 that are independent from each other in the actuator 10, and the coils 14 and 15 so that the ratio of the number of turns of the coils 14 and 15 satisfies the formula (6). The total inductance of the actuator coil can be reduced while maintaining the thrust generated by the actuator 10. And by reducing the total inductance, errors due to computations when calculating the back electromotive force are reduced, so that the accuracy of the relative speed can be improved, and the balance between the control effect and the control robustness can be improved. Can do.

  The error due to the calculation at the time of calculating the counter electromotive force increases as the frequency becomes higher. In this embodiment, since the calculation error at the time of calculating the counter electromotive force is small, it is possible to widen the control frequency band.

  Moreover, since the vibration reduction apparatus according to the present embodiment does not require a sensor for detecting the state of the actuator, it is possible to reduce the cost and reduce the size. Further, since the independent coil 15 can be used as a search coil, the back electromotive force necessary for estimating the relative speed can be easily detected.

In the present embodiment, the coil 15 is used as a search coil, but the coil 14 may be used as a search coil. In the above description, the embodiment in which the ratio (a ₁ , a ₂ ) of the number of turns of the coils 14 and 15 is 0.5 and the ratio of the number of turns of the coils 14 and 15 satisfies the formula (6) is mainly described. As described above, the ratio (a ₁ , a ₂ ) of the number of turns of the coils 14 and 15 need not be limited to 0.5, and also when the ratio of the number of turns of the coils 14 and 15 satisfies the formula (7). Similarly to the above, the total inductance of the actuator coil can be reduced while maintaining the thrust generated in the actuator 10.

  Moreover, the actuator coil provided in the actuator 10 is not necessarily limited to two independent coils, and may be three or more independent coils. Hereinafter, the case where an actuator coil is comprised by four coils is demonstrated as the modification 1 and the modification 2. FIG.

In the vibration reduction device according to the first modification of the present embodiment, four independent coils are provided in the actuator 10. The four coils are the same coils as the coils 14 and 15 described above. The ratio of the number of turns of the four coils (a ₁ , a ₂ , a ₃ , a ₄ ) corresponds to 0.5. In the first modification, the total inductance of the actuator 10 is the same as the total inductance of the comparative example, but the thrust generated by the actuator 10 is twice that of the comparative example.

In the vibration reduction device according to the second modification of the present embodiment, the actuator 10 is provided with four coils that are independent of each other. The number of turns of the four coils is N / 3, N / 4, N4, and N / 6. The ratio of the number of turns of the four coils (a ₁ , a ₂ , a ₃ , a ₄ ) is as follows: a ₁ = 1/3, a ₂ = a ₃ = 1/4, a ₄ = 1/6 Equivalent to. Further, the ratio of the number of turns of the four coils according to the modified example 2 satisfies the above formula (7). In the modified example 2, the total inductance of the actuator 10 is reduced to (19/72) L compared to the inductance (L) of the comparative example, and the thrust generated in the actuator 10 has the same magnitude (Ka) as in the comparative example. )

  Note that the vibration reducing apparatus according to the present embodiment may use a digital amplifier and an analog amplifier as amplifiers for control signals output from the controller 20 to the actuator 10. As a result, the independent coil 15 driven by an analog amplifier having a low noise level can be used as a search coil, so that the detection accuracy of the back electromotive force necessary for relative speed estimation can be increased.

  The controller 20 corresponds to the “control means” of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Actuator 11 ... Inertial mass 12 ... Leaf spring 13 ... Core 14, 14a, 14b, 15, 15a, 15b, 18 ... Coil 16 ... Magnet 17 ... Shaft 20 ... Controller 21 ... Amplifier 200 ... Torque rod 201 ... Rod axial part 202, 203 ... Rod end 202a ... Outer cylinder 202b ... Inner cylinder 202c, 203c ... Elastic body 203a ... Outer cylinder 203b ... Inner cylinder

Claims (6)

A rod connecting the engine and the vehicle body;
An actuator for reciprocating an inertial mass supported by the rod in a predetermined direction within the rod;
Control means for controlling the actuator to generate a force proportional to the speed of displacement of the rod in the predetermined direction;
The actuator has a plurality of independent coils,
The vibration reduction apparatus in which the ratio of the number of turns of the plurality of coils satisfies one of the following formulas (1) and (2).

Here, a ₁ , a ₂ ,..., _Am are values obtained by normalizing the number of turns of the plurality of coils, and m is a natural number of 2 or more. The vibration reducing device according to claim 1,
The plurality of coils are:
A first coil that reciprocates the inertial mass by generating a magnetic field by a current from a power source;
A second coil that receives a magnetic field generated by the first coil and generates a back electromotive force;
The control means includes
A vibration reduction device that measures the counter electromotive force and controls the current based on a measurement result. The vibration reduction device according to claim 1 or 2,
It has a digital amplifier that amplifies the control signal,
The said control signal is a signal for controlling the said actuator, The vibration reduction apparatus transmitted to the said actuator from the said control means. The vibration reduction device according to claim 1 or 2,
It has an analog amplifier that amplifies the control signal,
The said control signal is a signal for controlling the said actuator, The vibration reduction apparatus transmitted to the said actuator from the said control means. The vibration reduction device according to claim 1 or 2,
It has an analog amplifier and a digital amplifier that amplify the control signal,
The said control signal is a signal for driving the said actuator, The vibration reduction apparatus transmitted to the said actuator from the said control means. In the vibration reduction device according to any one of claims 1 to 5,
The rod has a shaft portion whose axial direction is the predetermined direction,
The vibration reducing device, wherein a resonance frequency of the rod in the predetermined direction is lower than an elastic resonance frequency of the engine.

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