CN107819421B

CN107819421B - Vibration control device and washing machine

Info

Publication number: CN107819421B
Application number: CN201710667446.3A
Authority: CN
Inventors: 法月邦彦; 岩路善尚; 中津川润之介; 马饲野佑贵
Original assignee: Hitachi Global Life Solutions Inc
Current assignee: Hitachi Global Life Solutions Inc
Priority date: 2016-09-13
Filing date: 2017-08-07
Publication date: 2020-12-08
Anticipated expiration: 2037-08-07
Also published as: CN112583324A; TWI688711B; CN107819421A; CN112583324B; TWI645113B; TW201812177A; TW201903288A

Abstract

The invention provides a low-cost vibration damping device and the like which properly restrain vibration of a vibration damping object. A vibration damping device (100) is provided with: a linear motor (10) connected to a vibration-damping object (G); an inverter (40) that drives the linear motor (10); a current detector (50) that detects a current flowing through the linear motor (10); and a thrust force adjustment unit (60) that adjusts the thrust force of the linear motor (10) by driving the inverter (40) on the basis of the current detected by the current detector (50). Thus, vibration of the vibration control object (G) can be appropriately suppressed.

Description

Vibration control device and washing machine

Technical Field

The present invention relates to a vibration control device and the like that control vibration of an object.

Background

As a device including a linear actuator, for example, patent document 1 describes a linear compressor that compresses gas by moving a piston in a cylinder by the linear actuator.

Patent document 2 describes a vibration damping control system including a position sensor for detecting a relative position of a mover of a linear actuator, and a control device for controlling vibration of an object based on a detection value of the position sensor and the like.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2003-214353

Patent document 2: japanese laid-open patent publication No. 2010-78075

Disclosure of Invention

In the technique described in patent document 1, the motor constant of the linear actuator is automatically tuned so that the piston of the linear compressor reciprocates between the top dead center and the bottom dead center without being excessively insufficient. That is, the technique described in patent document 1 keeps the amplitude of the linear actuator constant even when various conditions change, and does not change the amplitude at all times.

In addition, in the technique described in patent document 2, since a position sensor for detecting a relative position of the mover of the linear actuator is provided, the manufacturing cost may be increased.

Therefore, an object of the present invention is to provide a low-cost vibration control device and the like that appropriately controls vibration of an object.

In order to solve the above problem, the present invention is characterized by comprising: a linear actuator connected to the object; an inverter that drives the linear actuator; a current detector including current detection means for detecting a current flowing through the linear actuator; and a thrust adjusting unit that drives the inverter based on the current detected by the current detector to adjust a thrust of the linear motor.

Effects of the invention

According to the present invention, a low-cost vibration control device and the like that appropriately control vibration of an object are provided.

Drawings

Fig. 1 is a vertical cross-sectional view of a linear actuator provided in a vibration control device according to a first embodiment of the present invention.

Fig. 2 is a line II-II looking end view of fig. 1.

Fig. 3 is a perspective view of a vibration control device according to a first embodiment of the present invention.

Fig. 4 is a perspective view of a washing machine including a vibration control device according to a first embodiment of the present invention.

Fig. 5 is a longitudinal sectional view of a washing machine including a vibration control device according to a first embodiment of the present invention.

Fig. 6 is a configuration diagram of the vibration control apparatus according to the first embodiment of the present invention.

Fig. 7 is a configuration diagram including an inverter included in the vibration control device according to the first embodiment of the present invention.

Fig. 8 is an overall control block diagram of a thrust adjusting unit and the like including the vibration control device according to the first embodiment of the present invention.

Fig. 9 is a control block diagram equivalent to the primary delay element (1/(R + sL)) shown in fig. 8.

Fig. 10 is a configuration diagram of a vibration control apparatus according to a second embodiment of the present invention.

Fig. 11 is a control block diagram of a thrust adjusting unit included in the vibration control device according to the second embodiment of the present invention.

Fig. 12A is an experimental result showing changes in the rotation speed of the wash tank and the displacement of the outer tank in a comparative example using an oil damper with a fixed viscosity coefficient.

Fig. 12B is an experimental result showing changes in the rotation speed of the washing tub and the displacement of the outer tub in the second embodiment of the present invention.

Fig. 13 is a configuration diagram of a vibration control apparatus according to a third embodiment of the present invention.

Fig. 14 is a control block diagram including a thrust adjusting unit and a speed information estimating unit provided in the vibration control device according to the third embodiment of the present invention.

Fig. 15A is an explanatory diagram showing an example of a function used when generating the current command i based on the induced voltage Em in the vibration control device according to the third embodiment of the present invention.

Fig. 15B is an explanatory diagram showing another example of a function used when the current command i is generated based on the induced voltage Em in the vibration control device according to the third embodiment of the present invention.

Fig. 15C is an explanatory diagram showing another example of a function used when the current command i is generated based on the induced voltage Em in the vibration control device according to the third embodiment of the present invention.

Fig. 15D is an explanatory diagram showing another example of a function used when the current command i is generated based on the induced voltage Em in the vibration control device according to the third embodiment of the present invention.

Fig. 16 is a configuration diagram of a vibration control apparatus according to a fourth embodiment of the present invention.

Fig. 17 is a control block diagram including a thrust adjusting unit provided in the vibration control device according to the fourth embodiment of the present invention.

Fig. 18 is a configuration diagram of a vibration control device according to a modification of the present invention.

Fig. 19A is a structural diagram of a vibration control device according to a fifth embodiment of the present invention.

Fig. 19B shows the result of the thrust force generated when a fixed exciting force is applied in the first embodiment.

Fig. 19C shows the result of the thrust force generated when a fixed exciting force is applied in the fifth embodiment.

Fig. 20 is a configuration diagram of a vibration control apparatus according to a sixth embodiment of the present invention.

Fig. 21 is a control block diagram including a thrust adjusting unit and a speed situation estimating unit provided in the vibration control device according to the sixth embodiment of the present invention.

Fig. 22A is an explanatory diagram showing an example of a function used when generating a current command i based on an induced voltage Em in the vibration control device according to the sixth embodiment of the present invention.

Fig. 22B is an explanatory diagram showing another example of a function used when the current command i is generated based on the induced voltage Em in the vibration damping device according to the sixth embodiment of the present invention.

Fig. 22C is an explanatory diagram showing another example of a function used when the current command i is generated based on the induced voltage Em in the vibration damping device according to the sixth embodiment of the present invention.

Fig. 22D is an explanatory diagram showing another example of a function used when the current command i is generated based on the induced voltage Em in the vibration damping device according to the sixth embodiment of the present invention.

FIG. 23A shows washing tub 35 set at 900 (min) in a state where a weight of 600g is fixed at a predetermined offset position in washing tub 35 in accordance with the third embodiment of the present invention^-1) Vibration speed in the vertical direction of the outer groove during rotation and electricity to be supplied to the linear actuator 10The result of the flow.

FIG. 23B shows washing tub 35 set at 900 (min) in a state where a weight of 600g is fixed at a predetermined offset position in washing tub 35 in the sixth embodiment of the present invention^-1) The vibration speed in the vertical direction of the outer tank during rotation, and the current applied to the linear actuator 10.

Fig. 24 is a configuration diagram of a vibration control apparatus according to a seventh embodiment of the present invention.

Fig. 25 is a control block diagram including a thrust adjusting unit included in the vibration control device according to the seventh embodiment of the present invention.

Fig. 26A is a configuration diagram of a vibration control apparatus according to an eighth embodiment of the present invention.

Fig. 26B is a configuration diagram of a vibration control device according to an eighth embodiment of the present invention.

Fig. 27A is a structural diagram of a vibration control apparatus according to an eighth embodiment of the present invention.

Fig. 27B is a configuration diagram of a vibration control apparatus according to an eighth embodiment of the present invention.

In the figure: 100. 100A, 100B, 100C, 100D, vibration control device, 10-linear actuator, 10L-linear actuator (one linear actuator), 10R-linear actuator (the other linear actuator), 11-stator, 11 a-core, 11B-coil, 12-mover, 121B, 122B, 123B-permanent magnet, 20-spring, 31-base, 32-case, 32 a-left and right side plates, 32B-front cover, 32C-back cover, 32D-top cover, 33-door, H1-inlet, H2-opening H2 of washing tank 35, H3-opening H3, 34-operation and display panel of washing tank 37, H-drain hose, 35-washing tank, 36-elevator, 37-outer tank (object), 38-drive mechanism, 38 a-inverter for motor drive, 38B-motor, 39-blower unit, 40L, 40R-inverter, 50-current detector, F-rectifier circuit, F1-diode bridge circuit, E-AC power supply, D1, D2, D3, D4-diode, k 1-wiring, k 2-wiring, S1, S2, S3, S4, S5, S6, S11, S12, S13, S14-switching element, D-flywheel diode, Ch-smoothing capacitor, 60A, 60B, 60C, 60E-thrust adjusting part, 61, and,61A-arithmetic unit, Ke-induced voltage constant, 70B, 70C-speed information estimating unit, G-object, W-washing machine, C-viscosity coefficient of linear actuator 10, F_DDamping force of linear actuator, F_LThrust of the linear actuator 62, 66E, tables 70B, 70C, speed information estimation unit 63, subtractor 65, 65C, 67E, current command generation unit 64, ACR, 260A, 260B, 260C, 270A, energization voltage and energization current.

Detailed Description

In the following embodiments, a configuration in which the vibration of the washing machine W (see fig. 4) is controlled by the linear actuator 10 (see fig. 1) will be described as an example.

(first embodiment)

Fig. 1 is a vertical sectional view of a linear actuator 10 provided in a vibration control device.

Further, as shown in fig. 1, an xyz axis is defined. In fig. 1, half of the linear actuator 10 is shown in the x-direction, and the structure of the linear actuator 10 is symmetrical with respect to the yz plane.

The linear actuator 10 is a motor that linearly changes the relative position of the stator 11 and the mover 12 in the z direction by a magnetic attraction/repulsion (i.e., thrust) in the z axis direction between the stator 11 as an armature and the plate-shaped mover 12 extending in the z direction. As shown in fig. 1, the linear actuator 10 is connected to an outer tub 37 (object) of a washing machine W (see fig. 5). Specifically, the mover 12 of the linear actuator 10 is connected to the outer groove 37.

As shown in fig. 1, the linear actuator 10 includes a stator 11 and a mover 12. The stator 11 includes a core 11a formed by laminating electromagnetic steel plates in the z direction and a coil 11b wound around the magnetic pole teeth T of the core 11 a.

Fig. 2 is a line II-II looking end view of fig. 1. In fig. 2, the entire linear actuator 10 is illustrated instead of half of the linear actuator 10 in the x direction (see fig. 1).

As shown in fig. 2, the core 11a of the stator 11 includes an annular portion S and magnetic pole teeth T, T.

The annular portion S is annular (rectangular frame-shaped) in a longitudinal sectional view, and a magnetic circuit is formed by the annular portion S. The pair of magnetic pole teeth T, T extend inward in the y direction from the annular portion S and face each other. The distance between the magnetic pole teeth T, T is slightly longer than the thickness of the plate-shaped mover 12. The coil 11b is wound around each magnetic pole tooth T, T. By applying current to the coil 11b, the stator 11 functions as an electromagnet.

In the example shown in fig. 1, two pairs of magnetic pole teeth T are provided in the z direction (the moving direction of the mover 12). The coils 11b wound around the two pairs of magnetic pole teeth T form one coil, and both ends of the coil are connected to the output side of the inverter 40 (see fig. 6) described later.

The mover 12 shown in fig. 2 extends in the z direction through the annular core 11 a. As shown in fig. 1, the mover 12 includes a plurality of metal plates 12a extending in the z direction, and

permanent magnets

121b, 122b, and 123b provided on the metal plates 12a at predetermined intervals in the z direction. Further, a plurality of permanent magnets may be bonded to one metal plate, or a plurality of permanent magnets may be embedded in one metal plate.

Permanent magnets

121b, 122b, 123b shown in fig. 1 are magnetized in the y direction. More specifically, the permanent magnets (for example,

permanent magnets

121b and 123b) magnetized toward the y-direction positive side and the permanent magnet (for example, permanent magnet 122b) magnetized toward the y-direction negative side are alternately arranged in the z-direction. Then, a z-direction thrust is applied to the mover 12 by the attraction/repulsion of the mover 12 and the stator 11 functioning as an electromagnet. The "thrust" is a force that changes the relative position of the mover 12 and the stator 11.

Further, as the

permanent magnets

121b, 122b, 123b, samarium-iron-nitrogen permanent magnets are preferably used. The specific ratio (%) of the raw materials of the

permanent magnets

121b, 122b, 123b is, for example, iron: about 73%, samarium: about 24%, nitrogen: about 3%. In the above raw materials, the rare earth element is samarium.

On the other hand, in the conventional neodymium magnet, iron is often used: about 65%, neodymium: about 28%, dysprosium: about 5%, boron: neodymium magnet in a proportion of about 2%. In the above raw materials, the rare earth elements are neodymium and dysprosium. Therefore, the samarium-iron-nitrogen

permanent magnets

121b, 122b, and 123b have an advantage that the rare earth elements are less in proportion than the conventional neodymium magnet, and thus are less likely to be influenced by the market trend, and can be stably supplied.

Further, unlike conventional neodymium magnets and ferrite magnets, samarium-iron-nitrogen

permanent magnets

121b, 122b, and 123b can be molded by being incorporated in a resin. Therefore, the machining accuracy of the

permanent magnets

121b, 122b, and 123b can be improved and the dimensional variations can be reduced compared to the conventional art. Further, even if a waste portion of the raw material remains during the molding, the waste portion can be reused, so that there is no loss of the raw material, and the manufacturing cost can be reduced.

Fig. 3 is a perspective view of the vibration control device 100 including the linear actuator 10.

The vibration control device 100 is an electromagnetic suspension including the linear actuator 10 and the spring 20, and has a function of controlling vibration of the outer tub 37 (i.e., vibration of the washing machine W: see fig. 5) as an "object".

As shown in fig. 3, one end of the mover 12 of the linear actuator 10 is connected to the outer tub 37 of the washing machine W (see fig. 5), and the other end is connected to the fixing jig J. The stator 11 of the linear actuator 10 is not shown, and its movement is restricted by another fixing jig (not shown). Therefore, when the outer tub 37 of the washing machine W vibrates in the z direction, the mover 12 reciprocates in the z direction in accordance with the vibration, and the relative positional relationship between the mover 12 and the stator 11 changes.

The spring 20 is a spring that applies an elastic force to the stator 11, and is interposed between the stator 11 and the fixing jig J. As shown in fig. 3, the mover 12 penetrates the stator 11 and also penetrates the spring 20.

Fig. 4 is a perspective view of washing machine W provided with vibration control device 100.

Since vibration control device 100 is provided inside washing machine W (see fig. 5), vibration control device 100 is not shown in fig. 4.

The washing machine W shown in fig. 4 is a drum-type washing machine, and also has a function of drying clothes. Washing machine W includes vibration control device 100 (see fig. 5), base 31, casing 32, door 33, operation and display panel 34, and drain hose H.

The base 31 supports the case 32.

The box body 32 includes left and right side plates 32a, a front cover 32b, a rear cover 32c (see fig. 5), and an upper cover 32 d. A circular inlet h1 (see fig. 5) for taking out and putting in clothes is formed near the center of the front cover 32 b.

The door 33 is a lid that is provided at the inlet h1 and can be opened and closed.

The operation and display panel 34 is a panel provided with an electric switch, an operation switch, a display, and the like, and is provided on the upper cover 32 d.

The drain hose H is a hose for discharging the washing water in the outer tub 37 (see fig. 5), and is connected to the outer tub 37.

Fig. 5 is a vertical sectional view of washing machine W provided with vibration control device 100.

In addition to the above configuration, washing machine W includes washing tub 35, lifter 36, outer tub 37, drive mechanism 38, and blower unit 39.

The washing tank 35 accommodates clothes and has a bottomed cylindrical shape. The washing tub 35 is surrounded by an outer tub 37, and is supported coaxially with the outer tub 37 so as to be rotatable. A large number of through holes (not shown) for water and air to pass through are provided in the peripheral wall and the bottom wall of the washing tub 35. Opening h2 of washing tub 35 and opening h3 of outer tub 37 face door 33 in the closed state.

In the example shown in fig. 5, the rotation center axis of washing tub 35 is inclined so that the opening side becomes higher, but the present invention is not limited thereto. That is, the rotation center axis of the washing tub 35 may be horizontal or vertical.

The lifter 36 is provided on the inner peripheral wall of the washing tub 35, and lifts and drops the clothes during washing and drying.

The outer tank 37 is a bottomed cylinder for storing washing water and the like. As shown in fig. 5, the outer tub 37 encloses the washing tub 35. The linear actuator 10 (stator 11, mover 12) and the spring 20 are provided on the left and right sides of the outer groove 37, respectively. In fig. 5, one of the left and right linear actuators 10 is illustrated.

A drain hole (not shown) is provided in the lowermost portion of the bottom wall of the outer tub 37, and a drain hose H is connected to the drain hole. Then, the washing water is stored in the outer tank 37 in a state where a drain valve (not shown) provided in the drain hose H is closed, and the washing water is discharged by opening the drain valve.

The drive mechanism 38 is a mechanism for rotating the washing tub 35, and is provided outside the bottom wall of the outer tub 37. The rotation shaft of motor 38b (see fig. 7) provided in drive mechanism 38 penetrates the bottom wall of outer tub 37 and is connected to the bottom wall of washing tub 35.

Air blowing unit 39 feeds hot air into washing tub 35, and is disposed above washing tub 35. The blower unit 39 includes a heater (not shown) and a fan (not shown). Also, the air heated by the heater is sent to the washing tub 35 by the fan. Thereby, the clothes containing water are gradually dried in the washing tank 35.

Fig. 6 is a configuration diagram of the vibration control apparatus 100. In fig. 6, one of the two left and right linear actuators 10 is shown, and the other is omitted. The object G shown in fig. 6 is an outer tub 37 (see fig. 5) of the washing machine W (see fig. 5).

In addition to the above-described configuration (linear actuator 10 and spring 20: see fig. 3), the vibration control device 100 includes an inverter 40, a current detector 50, and a thrust adjusting unit 60.

The inverter 40 is an inverter that converts the dc voltage applied from the rectifier circuit F into a single-phase ac voltage based on the voltage command V from the thrust adjustment unit 60, and applies the single-phase ac voltage to the coil 11b of the linear actuator 10 (see fig. 2). That is, the inverter 40 has a function of driving the linear actuator 10 based on the voltage command V described above.

The "dc power supply" for applying a dc voltage to the inverter 40 includes an ac power supply E and a rectifier circuit F.

Fig. 7 is a configuration diagram including inverter 40 included in vibration control apparatus 100.

In fig. 7, the left linear actuator is referred to as "linear actuator 10L", and the right linear actuator is referred to as "linear actuator 10R".

The rectifier circuit F shown in fig. 7 is a well-known voltage-multiplying rectifier circuit that converts an ac voltage applied from an ac power supply E into a dc voltage. As shown in fig. 7, the rectifier circuit F includes a diode bridge circuit F1 formed by bridge-connecting diodes D1 to D4, and two smoothing capacitors Ch connected in series.

Then, the voltage (dc voltage including a ripple current) applied from the diode bridge circuit F1 is smoothed by the smoothing capacitor Ch, and a dc voltage corresponding to approximately 2 times the voltage of the ac power supply E is generated.

The rectifier circuit F is connected to the inverter 40 via a positive wiring k1 and a negative wiring k2, and also connected to an inverter 38a of the drive mechanism 38 for rotating the washing tub 35 (see fig. 5). The drive mechanism 38 includes a motor drive inverter 38a and a motor 38 b.

The inverter 40 is a three-phase full-bridge inverter that converts the dc voltage applied from the above-described "dc power supply" into a single-phase ac voltage and applies the single-phase ac voltage to the coils 11b (see fig. 2) of the

linear actuators

10L, 10R.

As shown in fig. 7, inverter 40 has a configuration in which a first leg including switching elements S1 and S2, a second leg including switching elements S3 and S4, and a third leg including switching elements S5 and S6 are connected in parallel. As the switching elements S1 to S6, for example, an igbt (insulated Gate Bipolar transistor) can be used. Flywheel diodes D are connected in antiparallel to the switching elements S1 to S6, respectively.

The connection point of the switching elements S1 and S2 is connected to the coil 11b (see fig. 2) of the linear actuator 10L via a wiring k 3. That is, the leg corresponding to one of the three-phase inverters 40 is connected to the left (one) linear actuator 10L.

The connection point of the switching elements S5 and S6 is connected to the coil 11b (see fig. 2) of the linear actuator 10R via a wiring k 5. That is, the other leg corresponding to one of the three-phase inverters 40 is connected to the right (other) linear actuator 10L.

The connection point of the switching elements S3 and S4 is connected to the coil 11b (see fig. 2) of the linear actuator 10L via the wiring k4, and is also connected to the coil 11b of the linear actuator 10R via the wiring k 4. That is, the remaining legs of the three-phase inverter 40 are connected to the left (one) linear actuator 10L and the right (the other) linear actuator 10R.

In this way, one inverter 40 is used for both the left and right sides without providing an inverter for each of the left and right

linear actuators

10L, 10R, and the cost of the inverter 40 can be reduced. Then, on/off of the switching elements S1 to S6 is controlled based on PWM control (Pulse Width Modulation), whereby a single-phase ac voltage is applied to the coils 11b (see fig. 2) of the

linear actuators

10L and 10R.

The current detector 50 detects the current flowing through the

linear actuators

10L and 10R, and is provided on the wiring k 6. That is, the current flowing through the coil 11b (see fig. 2) of the

linear actuator

10L, 10R is detected by the current detector 50. The wiring k6 is a wiring connecting the transmitters of the switching elements S2, SS4, and S6 and the input side of the inverter 38 a.

The thrust force adjusting unit 60 shown in fig. 6 is not shown, and includes electronic circuits such as a cpu (central Processing unit), a rom (read Only memory), a ram (random Access memory), and various interfaces. Then, the program stored in the ROM is read out and developed to the RAM/CPU to execute various processes.

The thrust adjusting unit 60 has a function of adjusting the thrust of the linear actuator 10 by driving the inverter 40 based on the current i detected by the current detector 50. That is, the thrust adjusting unit 60 generates a predetermined voltage command V based on the current, and switches the switching elements S1 to S6 on and off based on the voltage command V. As will be described in detail later, when the relative position between the mover 12 and the stator 11 changes due to the vibration of the outer groove 37 (see fig. 5), the thrust adjusting unit 60 adjusts the thrust of the linear actuator 10 so as to cancel the change.

Here, the vibration of outer tub 37 (i.e., the vibration of washing machine W) will be briefly described. In the washing, rinsing, and drying, the washing tub 35 is rotated at a low speed by the driving mechanism 38 shown in fig. 5, and the tumbling operation of lifting and dropping the clothes stored at the bottom of the washing tub 35 by the lifter 36 is repeated. In addition, during dehydration, the washing tank 35 rotates at a high speed, and centrifugal dehydration is performed in which moisture in the clothes is thrown out by the centrifugal force of the rotation.

In addition, in the conventional washing machine, the amplitude of vibration of the washing tub 35 is often increased by the reaction force of the dropped clothes during washing, rinsing, and drying. In addition, in the conventional washing machine, vibration and noise are often generated in the washing machine W due to the displacement of the clothes during the dewatering. In this way, the vibration mode of washing machine W changes from time to time depending on the amount, positional deviation, and water content of the laundry in washing tub 35, and also depending on the conditions of washing, rinsing, drying, dewatering, and the like. Its vibration propagates to the outer tank 37.

Fig. 8 is a control block diagram of the whole including the thrust adjusting unit 60 and the like.

As shown in fig. 8, the thrust force adjustment unit 60 includes an arithmetic unit 61. The calculator 61 has a function of calculating a voltage command V of the converter 40 by multiplying the current i detected by the current detector 50 by a predetermined current proportional gain Kp.

The value of the current i increases as the speed of the mover 12 (see fig. 3) of the linear actuator 10 increases. Therefore, the thrust adjusting unit 60 adjusts the voltage command V so as to increase the current i (i.e., decrease the speed of the mover 12 connected to the outer tub 37).

By controlling the inverter 40 based on the voltage command V, a predetermined voltage V is applied to the coil 11b (see fig. 2) of the linear actuator 10. The flow until this voltage V reflects the velocity of the mover 12 (in fig. 8, it is described as "x" plus one ". cndot.") is shown in the box line Q. In addition, x (m) is the position of the mover 12.

That is, a voltage (V-Em) obtained by subtracting the induced voltage Em of the linear actuator 10 from the voltage V on the output side of the inverter 40 is applied to the coil 11 b. A predetermined current i flows through the coil 11b due to the voltage (V-Em) and the primary delay element (1/(R + sL)) based on the resistance R and the inductance L of the coil 11 b. A value obtained by multiplying the current i by a motor constant Kt (also referred to as a "thrust constant") representing the characteristics of the linear actuator 10 becomes the thrust of the linear actuator 10. That is, a thrust force is generated to move the relative position of the stator 11 and the mover 12 in the z direction. Also, the velocity of the mover 12 changes due to the thrust and the integral element (1/sM) described above. Further, M is the mass of the outer tank 37.

An induced voltage Em equal to a value obtained by multiplying the velocity of the mover 12 by an induced voltage constant Ke is generated in the coil 11b (see fig. 2) of the linear actuator 10. The induced voltage Em changes from moment to moment due to the vibration of the outer tank 37, and the current i flowing through the coil 11b also changes accordingly. Based on the current i, the thrust adjusting unit 60 adjusts the thrust of the linear actuator 10 to control the vibration of the outer tub 37.

For example, in the vibration of the outer groove 37, the mover 12 (see fig. 3) moves upward in the z direction, and the thrust adjusting unit 60 generates a downward thrust that suppresses the movement of the mover 12 (i.e., the vibration of the outer groove 37) in the linear actuator 10. On the other hand, when the mover 12 moves downward in the z direction, the thrust adjusting unit 60 generates an upward thrust that suppresses the movement of the mover 12 in the linear actuator 10. Thereby, the vibration of outer tub 37 is suppressed, and thus, the vibration of washing machine W is suppressed.

(Effect)

According to the first embodiment, the thrust adjusting section 60 generates thrust to cancel out the vibration of the outer tank 37 based on the current i flowing in the linear actuator 10. Thus, the vibration control device 100 can appropriately suppress the vibration of the outer tub 37 by a relatively simple method.

In addition, according to the first embodiment, since it is not necessary to provide a position sensor for detecting the position of the mover 12, it is possible to reduce the cost of the washing machine W. Further, since the linear actuator 10 hardly causes damage or wear of the components (the stator 11 and the mover 12), the durability of the vibration control device 100 can be improved.

The single-phase ac voltage applied to the left and right

linear actuators

10L, 10R (see fig. 7) is generated by one inverter 40. Therefore, as compared with a configuration in which inverters are provided corresponding to the left and right

linear actuators

10L, 10R, respectively, cost reduction of the washing machine W can be achieved.

Further, by using the

permanent magnets

121b, 122b, 123b (see fig. 1) of samarium-iron-nitrogen system, as described above, the

permanent magnets

121b, 122b, 123b can be reduced in cost as compared with the conventional technique using neodymium magnets. Therefore, the manufacturing cost of the washing machine W can be reduced.

(modification of the first embodiment)

In the first embodiment, the current proportional gain Kp in the thrust force adjusting unit 60 was described as being fixed, but the viscosity coefficient C (Ns/m) of the linear actuator 10 may be changed by changing the magnitude of the current proportional gain Kp. A method of changing the viscosity coefficient C will be described.

The equation of motion of the vibration control apparatus 100 as an electromagnetic suspension is expressed by the following equation (1). Fd (n) shown in expression (1) is a force generated by the vibration control apparatus 100 (i.e., a damping force generated by the linear actuator 10).

(formula 1)

In addition, the equation of motion of the thrust of the linear actuator 10 is expressed by equation (2). Further, F_L(N) is the thrust of the linear actuator 10, and Kt (N/a) is the motor constant of the linear actuator 10. Further, i (a) is a current flowing through the coil 11b (see fig. 2), and v (v) is a voltage applied to the coil 11 b. R (Ω) is the resistance of the coil 11b, and Φ (T) is the magnetic flux generated by the coil 11 b.

(formula 2)

Here, the damping force FD of the formula (1) and the thrust force F of the formula (2) are due to_LEquivalently, the following formula (3) can be derived. Further, C (Ns/m) is a viscosity coefficient of the linear actuator 10.

(formula 3)

For example, if the magnitude of the resistance R shown in the formula (3) is changed, the magnitude of the viscosity coefficient C of the linear actuator 10 is also changed. Further, since the thrust force adjusting unit 60 (see fig. 8) changes the current proportional gain Kp, the same effect as that in the case of changing the resistance R can be produced. That is, by changing the current proportional gain Kp, the viscosity coefficient C of the linear actuator 10 changes (that is, the damping rate of the vibration control device 100 changes).

In the thrust adjusting unit 60 shown in fig. 8, the larger the current i detected by the current detector 50 (i.e., the larger the moving speed of the mover 12 caused by the vibration of the outer groove 37), the larger the current proportional gain Kp is. This generates a larger thrust force by the linear actuator 10, and can effectively suppress vibration of the outer groove 37.

(second embodiment)

The second embodiment is different from the first embodiment in that the thrust force adjusting unit 60A (see fig. 10) changes the viscosity coefficient C of the linear actuator 10 based on the current i flowing through the linear actuator 10 and the vibration frequency f of the outer tank 37. Other points (the structure of the linear actuator 10, the washing machine W, and the like) are the same as those of the first embodiment. Therefore, portions different from those of the first embodiment will be described, and redundant portions will not be described.

Fig. 10 is a configuration diagram of a vibration control apparatus 100A according to the second embodiment.

As shown in fig. 10, the vibration control device 100A includes a linear actuator 10, an inverter 40, a current detector 50, and a thrust adjusting unit 60A.

The thrust force adjusting unit 60A has a function of calculating a voltage command V of the inverter 40 by multiplying the current i detected by the current detector 50 by a predetermined current proportional gain Kp. The thrust force adjusting unit 60A has a function of decreasing the above-mentioned current proportional gain Kp as the vibration frequency f of the outer tank 37 (object G) is higher.

Further, the vibration frequency f of the outer tub 37 is proportional to the rotation speed of the washing tub 35. Therefore, the thrust force adjusting unit 60A calculates the vibration frequency f of the outer tub 37 based on the rotational frequency of the washing tub 35 input from the above-described driving mechanism 38 (see fig. 5). Therefore, a sensor for detecting the vibration frequency f of outer tub 37 is not provided, and cost reduction of washing machine W can be achieved.

Fig. 11 is a control block diagram of the thrust adjusting unit 60A included in the vibration control device 100A.

As shown in fig. 11, the thrust force adjustment unit 60 includes an arithmetic unit 61 and a table 62.

The arithmetic unit 61 calculates the voltage command V by multiplying the current i detected by the current detector 50 by a predetermined current proportional gain Kp.

Table 62 stores data indicating the relationship between the vibration frequency f of outer tub 37 and current proportional gain Kp in advance. Specifically, based on the data in table 62, as the vibration frequency f of outer tub 37 increases, current proportional gain Kp is set to a larger value. That is, the higher the vibration frequency f of the outer tank 37 is, the smaller the viscosity coefficient C of the vibration control device 100A (see fig. 10) is, the larger the thrust force is generated by the linear actuator 10. This can effectively suppress vibration of the outer tub 37.

Since the vibration frequency f of the outer tub 37 changes at every moment in accordance with the weight, position, operation mode, and the like of the clothes in the washing tub 35, the thrust force adjusting unit 60 changes the current proportional gain Kp at every moment in accordance therewith.

(Effect)

According to the second embodiment, the viscosity coefficient C of the linear actuator 10 is variably controlled based on the vibration frequency f of the outer tank 37. Therefore, compared to the first embodiment, the vibration of the outer tub 37 can be suppressed more effectively.

Fig. 12A is an experimental result showing changes in the rotation speed of the wash tank 35 and the displacement of the outer tank 37 in a comparative example using an oil damper with a fixed viscosity coefficient C.

In the experiment of fig. 12A, the washing tub 35 was rotated in a state where 1kg of clothes was placed at a predetermined offset position in the washing tub 35 (the same applies to fig. 12B).

As shown in fig. 12A, as the rotation speed of washing tub 35 increases, the amplitude of outer tub 37 changes. Specifically, the rotation speed of the washing tub 35 is increased from zero to about 50 (min)^-1) At a rotation speed of (2), the amplitude of the outer tub 37 is temporarily reduced to about 100 (min)^-1) The amplitude of the outer groove 37 sharply increases at the rotation speed of (1) to reach the maximum amplitude. In addition, the temperature is 105 to 170 (min)^-1) At a rotation speed of (2), the amplitude of the outer tub 37 increases at 200 (min)^-1) In the above region, as the rotation speed of washing tub 35 increases, the amplitude of outer tub 37 decreases.

Fig. 12B is an experimental result showing changes in the rotation speed of the washing tank 35 and the displacement (vibration) of the outer tank 37 in the second embodiment.

In the experiment shown in fig. 12B, the viscosity coefficient C of the linear actuator 10 is smaller as the rotation speed of the washing tank 35 is larger (i.e., the vibration frequency f of the outer tank 37 is higher).

As shown in FIG. 12B, the rotational speed of the washing tank 35 is about 100 (min)^-1) The maximum amplitude of the outer groove 37 in this case is about 5mm, which is about half of the maximum amplitude (about 10mm) of the comparative example shown in fig. 12A. Further, the rotational speed of the washing tank 35 is 500 (min)^-1) In the above region, the amplitude of the outer groove 37 is about 1 mm. In this way, according to the second embodiment, by variably controlling the viscosity coefficient C, the vibration of the outer tank 37 can be suppressed more effectively than in the first embodiment.

(third embodiment)

The third embodiment is different from the first embodiment in that it includes a speed information estimation unit 70B (see fig. 13) that estimates an induced voltage Em of the linear actuator 10 based on a current i flowing through the linear actuator 10 and a voltage command V of the inverter 40. The third embodiment is different from the first embodiment in that the thrust force adjusting unit 60B (see fig. 13) adjusts the thrust force of the linear actuator 10 based on the induced voltage Em and the current i flowing through the linear actuator 10. Other points (the structure of the linear actuator 10, the washing machine W, and the like) are the same as those of the first embodiment. Therefore, portions different from those of the first embodiment will be described, and redundant portions will not be described.

Fig. 13 is a configuration diagram of a vibration control apparatus 100B according to a third embodiment.

As shown in fig. 13, the vibration control device 100B includes a linear actuator 10, an inverter 40, a current detector 50, a thrust adjusting unit 60B, and a speed information estimating unit 70B.

The speed information estimation unit 70B is not shown, and includes an electronic circuit including a CPU, a ROM, a RAM, various interfaces, and the like, reads a program stored in the ROM, and develops the program into the RAM, so that the CPU executes various processes.

The speed information estimation unit 70B estimates the induced voltage Em generated by the linear actuator 10 based on the current i detected by the current detector 50 and the voltage command V of the inverter 40 calculated by the thrust adjustment unit 60B. The induced voltage Em is represented by the following formula (4). The voltage V, the resistance R, and the inductance L are as described in the first embodiment.

(formula 4)

The speed information estimation unit 70B calculates the induced voltage Em of the linear actuator 10 based on the equation (4), and outputs the value of the induced voltage Em to the thrust adjustment unit 60B.

As shown in the following equation (5), the induced voltage Em of the linear actuator 10 is proportional to the speed of the mover 12 (i.e., the speed of the vibrating outer groove 37). Therefore, the induced voltage Em can be said to be "a value corresponding to the speed of the outer tank 37".

(formula 5)

Fig. 14 is a control block diagram including a thrust adjusting unit 60B and a speed information estimating unit 70B provided in the vibration control device 100B.

The thrust adjusting unit 60B generates a predetermined voltage command V based on the current i detected by the current detector 50 and the induced voltage Em calculated by the speed information estimating unit 70B.

As shown in fig. 14, the thrust adjusting unit 60B includes a subtractor 63, an ACR64(Automatic current regulator), and a current command generating unit 65.

The subtractor 63 has a function of subtracting the current i, which is the detection result of the current detector 50, from the current command i, which is the calculation result of the current command generating unit 65.

The ACR64 has a function of calculating the voltage command V so that the current i approaches the current command i. Then, the inverter 40 is controlled based on the voltage V calculated by the ACR64 (see fig. 13).

The current command generating unit 65 has a function of calculating the current command i of the converter 40 so as to cancel the induced voltage Em based on the value of the induced voltage Em input from the speed information estimating unit 70B.

Fig. 15A is an explanatory diagram showing an example of a function used when the current command i is generated based on the induced voltage Em.

In the example shown in fig. 15A, the induced voltage Em is proportional to the current command i, and the proportionality coefficient is a negative value. That is, the absolute value of the current command i increases as the absolute value of the induced voltage Em increases in the current command generating unit 65 (i.e., the thrust adjusting unit 60B). As described above, as the induced voltage Em increases (the speed at which the outer tank 37 vibrates) the absolute value of the current command i increases, and thus the vibration of the outer tank 37 can be appropriately suppressed.

Fig. 15B is an explanatory diagram showing another example of a function used for calculating the current command i based on the induced voltage Em.

As shown in fig. 15B, the current command i (absolute value) for canceling the induced voltage Em may be set to a fixed value. Even in this case, the vibration of the outer tub 37 can be appropriately suppressed by the vibration control device 100B.

Fig. 15C is an explanatory diagram showing another example of a function used for calculating the current command i based on the induced voltage Em.

In the example shown in fig. 15C, the region where the induced voltage Em is not near zero is the same as that shown in fig. 15B, but the current command i is set to zero by the current command generating unit 65 (that is, by the thrust adjusting unit 60B) in the region where the induced voltage Em is near zero.

In the example of fig. 15B, since the positive and negative of the current command i are alternately changed in the region where the induced voltage Em is near zero, the operation of the linear actuator 10 is likely to become unstable in some cases. Therefore, as shown in fig. 15C, by providing a dead zone in which the current command i is zero, the thrust force of the linear actuator 10 can be stably controlled.

In the example of fig. 15A, since there is no upper limit of the current command i, the maximum current value of the linear actuator 10 or the inverter 40 may be exceeded in some cases. Therefore, as shown in fig. 15D, by setting an upper limit to the magnitude of the current command i, the current command i equal to or less than the maximum current value of the linear actuator 10 or the inverter 40 can be calculated.

(Effect)

According to the third embodiment, the induced voltage Em (a value corresponding to the speed of the outer tank 37) is estimated based on the current i and the voltage command V, and the linear actuator 10 is controlled based on the induced voltage Em and the like. That is, by generating the thrust of the linear actuator 10 so as to cancel out the speed of the outer groove 37 at each time, the vibration of the outer groove 37 can be effectively suppressed.

(fourth embodiment)

The fourth embodiment is different from the third embodiment in the method of adjusting the thrust of the linear actuator 10, and is otherwise the same as the third embodiment (the structures of the linear actuator 10, the washing machine W, and the like). Therefore, portions different from the third embodiment will be described, and redundant portions will not be described.

Fig. 16 is a configuration diagram of a vibration control apparatus 100C according to a fourth embodiment.

As shown in fig. 16, the vibration control device 100C includes a linear actuator 10, an inverter 40, a current detector 50, a thrust adjusting unit 60C, and a speed information estimating unit 70C.

The speed information estimation unit 70C estimates the induced voltage Em based on the voltage command V and the current i by the same method as the speed information estimation unit 70B (see fig. 13) described in the third embodiment.

The thrust force adjusting unit 60C has a function of calculating the voltage command V based on the current i, the induced voltage Em, and the vibration frequency f of the outer tank 37 (the object G).

Fig. 17 is a control block diagram including a thrust adjusting unit 60C included in the vibration control device 100C.

As shown in fig. 17, the thrust adjusting unit 60C includes a subtractor 63, an ACR64, a table 66, and a current command generating unit 67. The subtracter 63 and the ACR64 are the same as those in the third embodiment (see fig. 14), and therefore, the description thereof is omitted.

Table 66 stores data for generating current command i based on induced voltage Em and vibration frequency f of outer tank 37 in advance. Specifically, as in the second embodiment, the viscosity coefficient C of the linear actuator 10 is adjusted based on the vibration frequency f of the outer tank 37. That is, the current command generating unit 67 (i.e., the thrust adjusting unit 60C) increases the current command i as the vibration frequency f of the outer tub 37 increases.

Further, as in the third embodiment, the current command generating unit 67 calculates the current command i so as to cancel the induced voltage Em. In this way, in the fourth embodiment, control is performed in which the advantages of the second embodiment and the advantages of the third embodiment are produced. Then, the voltage command V is calculated in the ACR64 so that the current i approaches the current command i generated by the current command generating unit 67.

(Effect)

According to the fourth embodiment, the speed information estimating unit 70C estimates the induced voltage Em (a value corresponding to the speed of the outer tank 37) at each time, and the thrust adjusting unit 60C adjusts the thrust of the linear actuator 10 so as to cancel the induced voltage Em. Further, as the vibration frequency f of the outer tub 37 is higher, the current command i is set to a larger value, and therefore, the vibration of the outer tub 37 can be effectively suppressed. This can provide the washing machine W with low cost and high vibration damping performance.

(modification example)

The vibration control device 100 and the like of the present invention have been described above with reference to the embodiments, but the present invention is not limited to these descriptions, and various modifications are possible. For example, in each embodiment, a configuration in which the left and right

linear actuators

10L and 10R are driven by one inverter 40 (see fig. 7) has been described, but the present invention is not limited to this.

Fig. 18 is a configuration diagram of a vibration control device 100D according to a modification.

As shown in fig. 18, an inverter 40L that drives the left linear actuator 10L and an inverter 40R that drives the right linear actuator 10R may be provided separately.

Inverter 40L includes four switching elements S11 to S14 connected in a bridge. The connection point of the switching elements S11, S12 constituting the first leg and the connection point of the switching elements S13, S14 constituting the second leg are connected to the linear actuator 10L, respectively. The inverter 40R that drives the right linear actuator 10R also has the same configuration. By providing the two

inverters

40L and 40R in this way, the left and right

linear actuators

10L and 10R can be independently controlled.

(fifth embodiment)

The first embodiment described above has a function of calculating a voltage command V of the inverter 40 by multiplying the current i detected by the current detector 50 by a predetermined current proportional gain Kp. (refer to FIG. 8)

However, there is a problem that if the magnitude of current proportional gain Kp is changed, the response characteristic of the controller changes. For example, if the magnitude of current proportional gain Kp is increased, the response characteristic deteriorates.

The fifth embodiment is different from the first embodiment in that the voltage command V of the inverter 40 is obtained by adding two values, i.e., a value Vp obtained by multiplying the current i detected by the current detector 50 by a predetermined current proportional gain Kp and a value Vd obtained by multiplying the differential value of the current i detected by the current detector 50 by a current differential gain Kd (see fig. 8).

Other points (the structure of the linear actuator 10, the washing machine W, and the like) are the same as those of the first embodiment. Therefore, portions different from those of the first embodiment will be described, and redundant portions will not be described.

In fig. 8, a transfer function G1(s) having the induced voltage Em as an input and the current i detected by the current detector 50 as an output is expressed by equation (6).

(formula 6)

(formula 7)

Here, Tp represented by equation (7) is a time constant.

According to equation (7), for example, by increasing Kp, the magnitude of G1(s) shown in equation (6) can be increased. However, with an increase in Kp, the time constant Tp also increases. Therefore, it is known that the response performance is deteriorated and the phase lag is increased.

Fig. 19A is a control block diagram of the whole including the thrust adjusting unit 60D and the like.

As shown in fig. 19A, the thrust force adjustment unit 60D includes an arithmetic unit 61 and an arithmetic unit 61A (phase compensator). The arithmetic unit 61 has a function of calculating a voltage command Vp of the inverter 40 by multiplying the current i detected by the current detector 50 by a predetermined current proportional gain Kp.

The arithmetic unit 61A has a function of calculating the voltage command Vd of the inverter 40 by differentiating the current i detected by the current detector 50 and multiplying the current by a current differential gain Kd. Here, s is a differential sign.

The thrust force adjustment unit 60D calculates a value obtained by adding the voltage command Vp generated by the arithmetic unit 61 to the voltage command Vd generated by the arithmetic unit 61A as the voltage command V of the inverter 40.

For example, when the current i of the linear actuator 10 changes in a sine wave, the arithmetic unit 61 calculates a voltage command of a sine wave substantially in phase with the current. Further, since the arithmetic unit 61A differentiates the current i, it calculates a voltage command of a cosine wave having a leading phase of 90 degrees with respect to the current i. By adding the voltage command Vp generated by the arithmetic unit 61 to the voltage command Vd generated by the arithmetic unit 61A and leading the voltage command Vp by 90 degrees in phase, the phase of the voltage command V with respect to the current i can be advanced.

In fig. 19A, a transfer function G2(s) having the induced voltage Em of the linear actuator 10 as an input and the current i detected by the current detector 50 as an output is expressed by equation (8). Tdp represents a time constant and is expressed by equation (9). According to the formula (9), for example, by increasing Kp, the magnitude of G2(s) shown in the formula (8) can be increased.

Further, by adjusting the current differential gain Kd, the time constant Tdp can be set without depending on the set value of the proportional gain Kp, and the problem of phase lag due to deterioration of response performance, which is a problem in the first embodiment, can be solved.

Further, proportional gain Kp is set so as to fall within a range smaller than resistance R. In addition, the differential gain Kd is set in a range smaller than the inductance L.

(formula 8)

(formula 9)

(Effect)

According to the fifth embodiment, the time constant Tdp can be made variable by the current differential gain Kd. Therefore, compared to the first embodiment, the vibration of the outer tub 37 can be suppressed more effectively.

Fig. 19B is a result showing the thrust force generated from the linear actuator 10 when a fixed exciting force is applied in the first embodiment.

In the experiment of fig. 19B, a force of 50N was applied to the linear actuator 10 at 5 Hz. (the same applies to FIG. 19C)

As shown in fig. 19B, the excitation force and the thrust force do not have opposite phases, and the excitation force cannot be sufficiently cancelled.

Fig. 19C shows the result of the thrust force generated from the linear actuator 10 when a fixed exciting force is applied in the fifth embodiment. In the experiment shown in fig. 19C, the phase difference between the excitation force and the thrust force is close to 180 degrees, and the thrust force has an effect of canceling the excitation force.

For example, the current differential gain Kd may be variably controlled in accordance with the rotation speed or vibration frequency of the object. This allows the magnitude of the transfer function G2(s) to be varied, thereby enabling adjustment of vibration damping performance.

For example, the current differential gain Kd may also be assigned in such a manner that the time constant Tdp is fixed. Thus, even when proportional gain Kp is variable, the time constant can be fixed, and the vibration damping performance can be fixed.

Further, the weight of the object (the magnitude of the load) may be measured, and the thrust of the linear actuator 10 may be adjusted based on the measurement result. For example, the viscosity coefficient C of the linear actuator 10 may be increased as the weight of the object is increased. This enables more effective control of the vibration of the object.

(sixth embodiment)

The sixth embodiment is different from the third embodiment in that the thrust adjusting unit 60D (see fig. 20) adjusts the thrust of the linear actuator 10 based on the induced voltage Em and the current i flowing through the linear actuator 10, and reduces the transmission force generated in the base 31 (see fig. 5).

The rest (the structure of the linear actuator 10, the washing machine W, and the like) is the same as the third embodiment. Therefore, portions different from the third embodiment will be described, and redundant portions will not be described.

Fig. 20 is a configuration diagram of a vibration control device 100D according to a sixth embodiment.

As shown in fig. 20, the vibration control device 100D includes the linear actuator 10, the inverter 40, the current detector 50, the thrust adjusting unit 60D, and the speed information estimating unit 70B.

Fig. 21 is a control block diagram including a thrust adjusting unit 60D and a speed information estimating unit 70B provided in the vibration control device 100D.

The thrust adjusting unit 60D generates a predetermined voltage command V based on the current i detected by the current detector 50 and the induced voltage Em calculated by the speed information estimating unit 70B.

As shown in fig. 21, the thrust adjusting unit 60D includes a subtractor 63, an ACR64(Automatic current regulator), and a current command generating unit 65C. The ACR64 is the same as that of the third embodiment (see fig. 14), and therefore, the description thereof is omitted.

The subtractor 63 has a function of subtracting the current i, which is the detection result of the current detector 50, from the current command i, which is the calculation result of the current command generating unit 65C.

Transmission force F generated in the base 31 by the control device 100 as an electromagnetic suspension_B(N) is represented by the following formula (10). K (N/m) shown in the formula (10) is the elastic modulus of the spring 20, F_L(N) is the thrust of the linear actuator 10, and Cm (Ns/m) is the viscosity coefficient generated by the frictional force or the like of either the control device 100 or the external phase 37.

(formula 10)

As can be seen from the equation (10), the thrust force F is obtained even when the linear actuator 10 is not energized_LWhen (N) is 0, the transmission force (N) is generated by the viscosity coefficient Cm (Ns/m) generated by the friction force. In particular, when the frequency of vibration is high, that is, when the rotation time of the washing tub 35 is long during dehydration or the like, the transmission F is present_B(N) increase, noise increase, and the like.

Therefore, in the present embodiment, the thrust force F of the linear actuator 10 is controlled so as to cancel the transmission force (N) generated by the viscosity coefficient Cm (Ns/m)_L(N) is provided. Specifically, the current command generating unit 65C has a function of calculating the current command i so as to amplify the induced voltage Em based on the value of the induced voltage Em input from the speed information estimating unit 70B (see fig. 21). That is, the linear actuator 10 is energized to amplify the vibration of the mover 12。

By amplifying the vibration amplitude of the mover 12, the transmission force (N) generated by Cm (Ns/m) is cancelled, and the transmission force (N) generated in the base 31 can be reduced as compared with the case where no current is supplied to the linear actuator 10. Further, as for the current command i of the inverter 40, the thrust F of the linear actuator 10 is desirably_LThe magnitude of (N) does not exceed the transmission force (N) generated by friction force and the like.

Fig. 22A is an explanatory diagram showing an example of a function used when the current command i is generated based on the induced voltage Em.

In the example shown in fig. 22A, the induced voltage Em is proportional to the current command i, and the proportionality coefficient thereof is a positive value. That is, the current command generating unit 65C (i.e., the thrust force adjusting unit 60C) increases the absolute value of the induced voltage Em as it increases. As described above, the larger the induced voltage Em (the larger the speed at which the outer tank 37 vibrates), the larger the absolute value of the current command i is, and thereby the vibration of the outer tank 37 can be appropriately amplified.

Fig. 22B is an explanatory diagram showing another example of the function used when calculating the current command i based on the induced voltage Em.

As shown in fig. 22B, the current command i (absolute value) for amplifying the induced voltage Em may be a fixed value. Even in this case, the vibration of the outer tub 37 can be appropriately amplified by the vibration control device 100C.

Fig. 22 is an explanatory diagram showing another example of a function used for calculating the current command i based on the induced voltage Em.

In the example shown in fig. 22C, the region in the vicinity of the induced voltage Em that is not zero is the same as that shown in fig. 22B, but in the region in the vicinity of the induced voltage Em that is zero, the current command i is set to zero by the current command generating unit 65C (that is, by the thrust adjusting unit 60C).

In the example of fig. 22A, since there is no upper limit of the current command i, the maximum current value of the linear actuator 10 or the inverter 40 may be exceeded in some cases. Therefore, as shown in fig. 22D, by setting an upper limit to the magnitude of the current command i, the current command i equal to or less than the maximum current value of the linear actuator 10 or the inverter 40 can be calculated, and demagnetization of the linear actuator 10 and damage to the inverter 40 can be prevented.

FIG. 23A shows a state where the weight of 600g is fixed at a predetermined offset position in washing tub 35 in the third embodiment, and washing tub 35 is set at 900 (min)^-1) The vibration speed in the vertical direction of the outer tank during rotation, and the current applied to the linear actuator 10.

FIG. 23B shows the sixth embodiment in which the weight of washing tub 35 is set to 900 (min) in a state where 600g of the weight is fixed at a predetermined offset position in washing tub 35^-1) The vibration speed in the vertical direction of the outer tank during rotation, and the current applied to the linear actuator 10.

In the sixth embodiment, the speed of the wash 35 and the current i of the linear actuator 10 are generally in phase.

(Effect)

According to the sixth embodiment, the induced voltage Em (a value corresponding to the speed of the outer tank 37) is estimated based on the current i and the voltage command V, and the linear actuator 10 is controlled based on the induced voltage Em and the like. That is, by generating the thrust of the linear actuator 10 so as to amplify the speed of the outer groove 37 at each time, that is, generating the thrust of the linear actuator 10 so as to have the same phase as the induced voltage Em, the transmission force (N) generated by the friction force or the like can be cancelled, and the transmission force generated in the base 31 can be effectively suppressed.

(seventh embodiment)

The seventh embodiment differs from the sixth embodiment in the method of adjusting the thrust of the linear actuator 10, but is otherwise the same as the sixth embodiment (the structure of the linear actuator 10, the washing machine W, and the like). Therefore, portions different from those of the sixth embodiment will be described, and redundant portions will not be described.

Fig. 24 is a configuration diagram of a vibration control apparatus 100E according to the seventh embodiment.

As shown in fig. 24, the vibration control device 100E includes the linear actuator 10, the inverter 40, the current detector 50, the thrust adjusting unit 60E, and the speed information estimating unit 70C.

The thrust force adjusting unit 60E has a function of calculating the voltage command V based on the current i, the induced voltage Em, and the vibration frequency f of the outer tank 37 (the object G).

Fig. 25 is a control block diagram including a thrust adjusting unit 60E included in the vibration control device 100E.

As shown in fig. 25, the thrust adjusting unit 60E includes a subtractor 63, an ACR64, a table 66, and a current command generating unit 67E. The subtracter 63 and the ACR64 are the same as those in the third embodiment (see fig. 14), and therefore, the description thereof is omitted.

Data for generating the current command i based on the induced voltage Em and the vibration frequency f of the outer tank 37 is stored in advance in the table 66E. Specifically, the viscosity coefficient C of the linear actuator 10 is adjusted based on the vibration frequency f of the outer tank 37. That is, the current command generating unit 67E (i.e., the thrust adjusting unit 60E) increases the current command i as the vibration frequency f of the outer tub 37 increases.

Further, the current command generating unit 67 calculates the current command i so as to amplify the induced voltage Em, as in the sixth embodiment. In this way, in the seventh embodiment, the control that has the merits of the sixth embodiment is performed. Then, the voltage command V is calculated in the ACR64 so that the current i approaches the current command i generated by the current command generating unit 67E.

(Effect)

According to the seventh embodiment, the speed information estimating unit 70C estimates the induced voltage Em (a value corresponding to the speed of the outer tank 37) at each time, and the thrust adjusting unit 60E adjusts the thrust of the linear actuator 10 so as to amplify the induced voltage Em. Further, since the current command i is set to a larger value as the vibration frequency f of the outer tub 37 is higher, the transmission force generated in the base 31 can be effectively suppressed. This can provide the washing machine W with low cost and high vibration damping performance.

(eighth embodiment)

In the eighth embodiment, a method of avoiding a dead zone of a current caused by a dead time in the inverter 40 used in the first to seventh embodiments will be described.

In the configuration diagram shown in inverter 40 in fig. 7, for example, when switching element S1 and switching element S2 are simultaneously turned on, the power supply may be short-circuited, and the switching element may be broken. Therefore, when the switching elements included in the legs are on/off controlled, that is, so that the two switching elements included in the legs are not on at the same time, the dead time period Td is set after one of the elements is on and before the other is on (see fig. 26A).

In the dead time period, a current flows through the flywheel diode (see fig. 7 and 40), and therefore, the voltage of each leg to be output is determined by the polarity of the current flowing when the switching element is turned on and off.

Fig. 26A illustrates the timing of turning on and off the switching elements S1 to S4 when the voltage command Vk3 and the voltage command Vk4 are given to the left and right coils of the linear motor 10L. Note that Tri shown in fig. 26A is a triangular carrier, and for example, when the voltage command Vk3 is larger than the triangular carrier Tri, on/off control is performed so that the switching element S1 is turned on and the switching element S2 is turned off.

A portion 260A surrounded by a broken line in fig. 26A indicates: the current Ik3 to be supplied to the linear motor 10L is a variation of the voltage Vk3 to be supplied from the first leg to the linear motor 10L, the voltage Vk4 to be supplied from the second leg, the line voltage Vk34 (obtained by subtracting the voltage of Vk4 from the voltage of Vk3), and the current Ik3 to be supplied to the linear motor 10L. A portion 260B surrounded by a broken line in fig. 26 shows a case where the current Ik3 to be supplied to the linear motor 10L is negative, and the meaning of each symbol is the same as that of the portion 206A. In the present embodiment, the current Ik3 is applied to the linear motor 10L from the first leg and is positive.

From fig. 26A, for example, when the current Ik3 is positive, the output voltage Vk3 is smaller than the voltage command Vk3, and the output voltage Vk4 is larger than the voltage command Vk 4. Therefore, an error occurs with respect to the voltage command Vk3 and the voltage command Vk4, and the control performance deteriorates.

Fig. 26B shows a case where voltage command Vk3 and voltage command Vk4 in fig. 26A are made close to each other as an example where the output voltage error due to the dead time is significant. This corresponds to a case where the voltage applied to the linear motor 10L is small, that is, a case where the current Ik3 is to be reduced. The reference numerals in section 260C are the same as those in section 260A, and therefore, the description thereof will be omitted. In the section 260C, the current Ik3 is positive.

In section 260C, the line voltage Vk34 decreases, that is, the energization time becomes shorter, due to the influence of the dead time. In the switching elements S1 to S4, a voltage drop occurs normally due to an on-resistance or the like. Therefore, when a voltage drop occurs in the switching element or the like and the output voltage is reduced by an amount corresponding to the voltage drop, the current Ik3 may not be controlled appropriately, that is, a dead zone of the current may be present.

Fig. 27 illustrates a method for avoiding a dead zone of a current due to a dead time or the like by adding modulation to a voltage command value. The voltage command value Vk3 is a voltage command value modulated in such a manner that, for each half of one carrier period TS(s), the auxiliary voltage dV is added during the first half TS1 and subtracted during the second half TS 2. That is, the voltage command value Vk3 is expression (11) during the period TS1, and expression (12) during the period TS 2.

(formula 11)

Vk3^**＝Vk3^*+ dV (TS1 time)

(formula 12)

Vk3^**＝Vk3^*dV (TS2 time)

In fig. 27A, only the voltage command Vk3 is modulated, but other phases may be modulated. The auxiliary voltage dV may be subtracted during TS1 and added during TS 2. In order to prevent the average voltage of the voltage command Vk3 in the TS period from changing, it is desirable that the magnitude of the auxiliary voltage dV applied in the TS1 period and the magnitude of the auxiliary voltage dV applied in the TS2 period be the same.

When an on/off command is issued to the switching elements S1 and S2 based on the voltage command value Vk3, the output voltage Vk3 is output with a delay in the timing of on/off of the output voltage Vk3 while maintaining the average voltage in the TS period (see 270A part Vk3 in fig. 27A). That is, the average value of the output voltage during TS1 and the average value of the output voltage during TS2 can be varied.

Fig. 27B shows a case where voltage command Vk3 and voltage command Vk4 are 0 as a modification of the present embodiment. Note that the symbols are the same as those in fig. 26A, and therefore, the description thereof is omitted. The voltage command Vk3 and the voltage command Vk4 are 0, and when only Vk3 is modulated, a pulse-shaped voltage of positive and negative targets can be observed in the line voltage Vk 34.

(Effect)

According to the eighth embodiment, the energization time of at least one of the TS1 period and the TS2 period of the output voltage Vk34 can be increased while maintaining the average of the line voltages Vk34 energized to the left and right coils of the linear motor 10L. Therefore, the dead zone of the current generated in the output voltage Vk34 due to the dead time or the like, which is described in fig. 26B or the like, can be avoided.

In the present embodiment, the first leg and the second leg to which the linear motor 10L is connected, that is, the switching elements S1 to S4 are used in the description, but the same effects can be obtained also in the second leg and the third leg to which the linear motor 10R is connected, that is, the switching elements S3 to S6. In addition, the same effects can be obtained also in the configuration of the vibration control device according to the modification of the present invention shown in fig. 18.

In each embodiment, a structure in which the spring 20 is provided between the stator 11 (see fig. 3) and the fixing jig J is described, but the present invention is not limited to this. For example, instead of the spring 20, a mechanism using rubber or hydraulic pressure may be applied.

In each embodiment, a configuration in which the mover 12 is connected to the outer tub 37 as the target object has been described, but the present invention is not limited to this. That is, one of the stator 11 and the mover 12 may be connected to the object, and the relative position between the stator 11 and the mover 12 may be changed by the magnetic attraction/repulsion.

In the embodiments, the vibration control device 100 and the like are used to control the vibration of the washing machine W, but the present invention is not limited to this. For example, the embodiments can be applied to a railway vehicle, an automobile, and the like, in addition to home appliances such as an air conditioner, a refrigerator, and the like.

In addition, although the structure in which the linear actuator 10 is driven by the single-phase ac power has been described in each embodiment, the linear actuator 10 may be driven by a three-phase ac power, for example.

The embodiments are described in detail to explain the present invention more easily for understanding, and are not limited to having all the configurations described. In addition, as for a part of the configuration of the embodiment, addition, deletion, or substitution of another configuration can be performed.

The above-described mechanisms and structures are shown in consideration of the necessity of description, and not all of the mechanisms and structures are necessarily shown in the product.

Claims

1. A vibration damping device is provided with:

a linear actuator connected to the vibration control object;

an inverter that drives the linear actuator;

a current detector for detecting a current flowing through the linear actuator; and

a thrust force adjusting unit that adjusts a thrust force of the linear actuator by driving the inverter based on the current detected by the current detector,

it is characterized in that the preparation method is characterized in that,

the thrust force adjusting unit calculates a voltage command of the inverter by multiplying a current detected by the current detector by a predetermined current proportional gain, and increases the current proportional gain as the current increases.

2. The vibration damping device according to claim 1,

the linear actuator includes a stator as an armature and a mover having a permanent magnet,

the permanent magnet is a permanent magnet of samarium-iron-nitrogen system.

3. The vibration damping device according to claim 1,

the thrust force adjusting unit includes:

a phase adjustment unit that controls a phase difference between a voltage command to the inverter and a current to be supplied to the linear actuator based on the current information detected by the current detector; and

and an amplitude adjustment unit for controlling the magnitude of the current of the linear actuator.

4. A vibration damping device is provided with:

a linear actuator connected to the vibration control object;

an inverter that drives the linear actuator;

it is characterized in that the preparation method is characterized in that,

the thrust force adjusting unit calculates a voltage command of the inverter by multiplying the current detected by the current detector by a predetermined current proportional gain, and increases the current proportional gain as the vibration frequency of the vibration control object increases.

5. The vibration damping device according to claim 4,

the permanent magnet is a permanent magnet of samarium-iron-nitrogen system.