JP2023020617A - Actuator, and drive unit for washing machine - Google Patents

Abstract

To make reciprocating motion of an actuator efficient and appropriate.SOLUTION: An actuator 100 comprises a movable member 120 that reciprocates along a stationary member 110. The stationary member 110 has an electric cable 113 and two magnets 114a, 114b. The movable member 120 has two salient pole cores 120a, 120a, and a connection core 120b connecting base end portions of the salient pole cores 120a, 120a. The movable member 120 reciprocates by switching the electric conduction direction of the electric cable 113.SELECTED DRAWING: Figure 1

Description

The disclosed technology relates to actuators and drive units for washing machines.

Home-use washing machines are required to have a compact size, large capacity, low noise, energy saving, and the like. Therefore, drive units for washing machines are being developed to meet these demands.

A washing machine requires a wide range of rotational force in each process, such as washing, rinsing, and spin-drying. In order to obtain such a wide range of torque, it has long been common practice to shift the transmission with a clutch.

In recent years, a drive unit that directly rotates a pulsator or a drum using a motor is becoming mainstream. In the case of such a drive unit, the rotational force can be changed by inverter control, but there is a limit in terms of cost and the like because the motor is required to have highly efficient performance. Therefore, switching technology using a transmission and a clutch is attracting attention again.

Furthermore, in recent years, since there is a need to widely change the rotational force of motors in the technical field of robots, etc., switching techniques using transmissions and clutches have also attracted attention.

Related to the disclosed technique, Patent Document 1 discloses a linear actuator.

The linear actuator consists of a stator with a core and coils, and a mover with magnets and yokes. The magnets of the mover are composed of a main magnet and a pair of spring magnets arranged on both sides of the main magnet.

US Pat. Nos. 5,300,000 and 5,000,003 disclose a drive unit for a washing machine with a clutch that includes a structure similar to the linear actuator of US Pat. The clutch includes a mover having a magnet whose magnetic poles are arranged in the order of SNS in the rotation axis direction, and a stator having a clutch coil.

JP 2006-288088 A Japanese Patent Application Laid-Open No. 2020-114288 JP 2020-124381 A

When the clutch is configured by a linear actuator having a magnet as a mover, there is a problem that a large driving force during the reciprocating motion of the clutch generates a strong impact sound when the clutch is switched, resulting in noise. In addition, the friction caused by the contact of the meshing portions of the clutch and the impact caused by the collision caused wear and damage of the clutch.

As a countermeasure for suppressing the impact noise, the clutch of Patent Document 3 proposes a method of providing a cushioning material at the contact portion. However, this method has a problem of high cost. The clutch of Patent Document 3 also proposes a method of generating a reverse driving force immediately before the clutch collides to mitigate the collision. However, there is a problem that it is difficult to control because it is necessary to instantaneously switch to the reverse current at appropriate timing.

Furthermore, if the mover has a magnet, there are problems such as the magnet being detached when the mover rotates at high speed and the manufacturing being difficult.

Therefore, in the technology disclosed, an actuator capable of performing reciprocating motions efficiently and appropriately is realized so as to solve such problems.

The disclosed technology relates to an actuator that includes a fixed member that is fixed and used, and a movable member that reciprocates along the fixed member in a predetermined first direction.

The fixing member is arranged in the first direction with electric wires that are positioned apart in a second direction that intersects with the first direction and that extend in a direction crossing both the first direction and the second direction. and two magnets arranged between the electric wire and the movable member and arranged such that the same magnetic poles of each magnet face the first direction, and the movable member is arranged in the first direction. two salient pole cores arranged side-by-side and each having a distal end portion capable of closely facing the two magnets; and a base end portion of the two salient pole cores spaced apart from the two magnets. and a connecting core for connecting the movable member to reciprocate by switching the energization direction of the electric wire.

That is, in this actuator, the movable member linearly reciprocates with respect to the fixed member by switching the direction of current flow. The movable member is only the core and has no magnets. Therefore, there is no fear that the magnet will come off even if it rotates at high speed. The movable member has two salient pole cores and a connecting core that form the magnetic flux path, and is simple in structure and easy to manufacture.

The fixed member is provided with an electric wire that forms a magnetic field with the movable member when energized, and a pair of magnets arranged in a predetermined arrangement with the same magnetic poles facing each other. By providing such magnets in the fixed member, the movable member can be stably held at two positions that are the starting points of the reciprocating motion when no power is supplied. By energizing the movable member, a smooth and appropriate propulsive force can be generated. As a result, the reciprocating motion of the movable member can be performed efficiently and appropriately, so that impact noise can be effectively suppressed.

The movable member is integrally formed using a plate-shaped soft magnetic material, and each tip portion of the salient pole core is provided with a flange projecting in the opposite direction to the first direction. may be

By providing such a flange, the movable member can be operated more stably.

The fixed member and the movable member may have circular shapes with their centers aligned, and the electric wire may form a coil wound around the centers. In this case, the movable member may be arranged inside the fixed member, or the movable member may be arranged outside the fixed member.

The disclosed technology also relates to drive units for washing machines.

The drive unit includes a drive shaft rotatably supported around a rotation shaft, a motor for rotating the drive shaft, and a clutch and a reduction gear interposed between the drive shaft and the motor, The clutch includes a movable portion that slides in the direction of the rotation axis in which the rotation shaft extends, a pair of fixed portions that are separated from each other in the direction of the rotation axis, and one of the fixed portions by sliding the movable portion. and a drive unit that switches the connection state of the speed reducer by doing so, and the drive unit is configured using the actuator.

The performance of the washing machine can be improved by using the above-described actuator for the driving portion of the clutch that switches the connection state of the speed reducer.

A control device for controlling the operation of the clutch is further provided, and the control device supplies a predetermined switching current to the clutch so that the movable portion is connected to one of the pair of fixed portions. The drive unit may execute a switching process for connection and a braking process for stopping supply of the switching current to the clutch immediately before the movable portion is connected to the one fixed portion.

By doing so, the impulsive sound can be effectively suppressed by simple control to stop the supply of the switching current, that is, to turn off the energization.

A control device for controlling the operation of the clutch is further provided, and the control device supplies a predetermined switching current to the clutch so that the movable portion is connected to one of the pair of fixed portions. The drive unit may execute a switching process for coupling and, when executing the switching process, a switching determination process for judging whether or not the movable portion is coupled to the one fixed portion.

Specifically, the control device may perform the switching determination process by comparing the current flowing through the coil with a predetermined determination value immediately after the switching process is performed.

In such a case, the control device sets, as the determination value, the current that flows through the coil by energizing the coil based on a predetermined voltage command value for determination immediately before executing the switching process. and the current flowing through the coil based on the determination voltage command value immediately after the switching process is executed.

By doing so, it is possible to determine with high accuracy whether the switching of the clutch is successful or not, so that troubles such as abnormal noise caused by defective switching can be prevented from occurring.

According to the actuator to which the disclosed technology is applied, reciprocating motion can be performed efficiently and appropriately, so collision noise can be easily suppressed.

FIG. 4 is a schematic cross-sectional view of an actuator; FIG. 4 is a diagram for explaining the relationship between the state of actuators and propulsive force; FIG. 4 is a magnetic flux diagram when the movable member is displaced from the first position to the second position; 1 is a schematic diagram showing the structure of a washing machine to which the technology disclosed is applied; FIG. FIG. 3 is a schematic side view showing the appearance of a drive unit; 4 is an exploded perspective view showing main members of the drive unit; FIG. FIG. 4 is a schematic cross-sectional view of a main part of the drive unit; FIG. 4 is a schematic perspective view showing portions of the shaft and rotor; It is a schematic perspective view showing a portion of a stator. It is a schematic perspective view which shows the part of a reduction gear. FIG. 4 is a schematic perspective view showing portions of a speed reducer and a clutch; FIG. 4 is a schematic perspective view showing the essential parts of the speed reducer and the clutch. FIG. 4 is a schematic perspective view showing the essential parts of the speed reducer and the clutch. It is a figure explaining switching of a clutch. It is a flowchart which shows the basic operation example of a washing machine. 4 is a flow chart showing an example of clutch switching. 4 is a time chart of braking processing; 9 is a flowchart of switching determination processing;

Embodiments of the disclosed technology will be described in detail below with reference to the drawings. However, the following description is essentially merely an example, and does not limit the present invention, its applications, or its uses.

<Actuator>
FIG. 1 illustrates an actuator 100 based on the disclosed technology. FIG. 1 is a schematic cross-sectional view of an actuator 100. FIG.

The actuator 100 includes a stationary member 110 that is fixed and a movable member 120 that reciprocates along the stationary member 110 . The movable member 120 linearly reciprocates within a predetermined range in the direction indicated by arrow Y1 in FIG. 1 (first direction). That is, this actuator 100 is of a linear type. The fixed member 110 and the movable member 120 are arranged so as to face each other across a small gap (gap G) in a direction (second direction) intersecting (substantially perpendicular to) the first direction.

(fixing member 110)
The fixing member 110 is composed of an outer core 111, an inner core 112, an electric wire 113, two magnets 114a and 114b, and the like. Outer core 111 and inner core 112 are made of a soft magnetic material such as steel plate. The outer core 111 includes a pair of support wall portions 111a, 111a that are spaced apart in the first direction and face each other, a connection wall portion 111b that continues to each end of the support wall portions 111a, 111a on the side away from the movable member 120, and is integrally formed so that the cross section is U-shaped (arch).

The opening of the outer core 111 facing the connecting wall portion 111b faces the gap G. As shown in FIG. Each of the two magnets 114a and 114b is a magnet with a rectangular cross section, and is in close contact with the facing surface of each support wall portion 111a along the opening of the outer core 111. As shown in FIG. The two magnets 114a and 114b are aligned in the first direction.

These magnets 114a and 114b are magnetized so as to be oriented in the first direction, and arranged so that their north poles face each other in the first direction. That is, the magnets 114a and 114b are arranged such that the side of the support wall portion 111a of each of the magnets 114a and 114b is the S pole, and the N poles of the magnets 114a and 114b face each other.

The inner core 112 has a rectangular cross section and is arranged between the two magnets 114a and 114b in close contact therewith. The two magnets 114a, 114b and the inner core 112 are integrated and close the opening of the outer core 111. As shown in FIG.

As a result, these two magnets 114a and 114b and the inner core 112 face the gap G in an exposed state together with the ends of both supporting wall portions 111a and 111a of the outer core 111 . These exposed surfaces are flat and parallel to the first direction.

One or more electric wires 113 are accommodated in the space between these two magnets 114a and 114b, the inner core 112, and the connecting wall portion 111b. Note that the number of electric wires 113 is preferably as large as possible, and since there are usually a plurality of electric wires 113, a group of electric wires is used here. The wire group extends in a direction crossing (substantially orthogonal to) both the first direction and the second direction, that is, in a direction substantially perpendicular to the plane of the paper.

(movable member)
The movable member 120 has two salient pole cores 120a, 120a, a connecting core 120b, etc., and is integrally formed of a plate-shaped soft magnetic material. The movable member 120 is formed by bending a steel plate.

The two salient pole cores 120a, 120a extend in parallel in the second direction and are arranged side by side in the first direction at a predetermined interval. When the movable member 120 faces the fixed member 110, the tip portion of each salient pole core 120a is set to face the two magnets 114a and 114b. In this movable member 120, flanges 121 projecting in opposite directions in the first direction are provided at respective tip portions of salient pole cores 120a.

The proximal end portions of these two salient pole cores 120a, 120a located away from the two magnets 114a, 114b are connected by a connecting core 120b. Thereby, the cross section of the movable member 120 is formed in a so-called hat shape. In addition, the connecting core 120b may be separated from the magnet 114, and its shape may be V-shaped or U-shaped in cross section.

(Actuator operation)
The actuator 100 is configured to generate a driving force to hold the movable member 120 at the first position or the second position by the magnetic field formed between the movable member 120 and the fixed member 110 when no power is supplied. there is

Then, the movable member 120 is moved between a first position indicated by a solid line in FIG. reciprocate. In other words, switching the direction of current flow changes the magnetic field between the movable member 120 and the fixed member 110 . Thereby, a driving force is generated in the movable member 120, and the driving force changes according to the displacement.

FIG. 2 shows the relationship between the state of the actuator 100 and the driving force. The horizontal axis represents the position of the movable member 120 with respect to the fixed member 110 . The vertical axis represents the magnitude of the driving force toward the first position P1 or the second position P2.

A line L1 represents the change in propulsive force at each position when no current is supplied. A line L2 represents the change in propulsive force when the energization direction is energized in the direction from the near side toward the paper surface (second energization direction). A line L3 represents a change in propulsive force when the energization direction is energized in a direction (first energization direction) directed toward the viewer from the plane of the drawing. The chain double-dashed line L4 will be described later.

When no power is supplied, a propulsive force directed toward the first position P1 is generated at the first position P1, and a propulsive force directed toward the second position P2 is generated at the second position P2. Therefore, if the movable member 120 is positioned at the first position or the second position, the movable member 120 can be stably held at that position without energization.

Then, by energizing in the first energizing direction, a driving force toward the first position is generated as indicated by line L3. By energizing in the second energizing direction, a driving force toward the second position is generated as indicated by line L2. Therefore, by switching the energization direction, the movable member 120 can be reciprocated between the first position and the second position.

Moreover, the driving force generated by the energization can be made smaller after the movable member 120 reaches the position (P0, intermediate point) where the movable member 120 directly faces the fixed member 110 than the driving force before passing through the intermediate point. Since the latter half can be gently displaced, impact noise is suppressed.

FIG. 3 shows a magnetic flux diagram obtained by magnetic field analysis when the movable member 120 is displaced from the first position to the second position. The lines in each figure represent the magnetic flux. Similarly, arrow B represents the driving force acting on movable member 120 .

(a) is a state in which the movable member 120 is located at the first position. No current flows through the wire 113 (non-energized state). Of the two magnets 114a and 114b of the fixed member 110, the magnetic flux of the magnet 114a (the first magnet 114a) located on the first position side flows more in the movable member 120, so that the driving force toward the first position side is generated, and the movable member 120 is held at the first position.

(b) is a state in which the movable member 120 is located at the first position. The electric wire 113 is energized in the second energization direction. The energization weakens the magnetic flux flowing through the movable member 120 due to the first magnet 114a. Then, the magnetic force of the magnet 114b (second magnet 114b) located on the side of the second position generates a driving force toward the side of the second position, and the movable member 120 moves from the first position toward the second position. Displace.

(c) is a transient state in which the movable member 120 is displaced. The magnetic flux due to the energization and the magnetic flux of the first magnet 114a flow through the core of the fixed member 110 to the movable member 120, and the magnetic flux density of the movable member 120 increases. Therefore, the increase in the gap magnetic flux for applying the driving force is suppressed, and the driving force gradually decreases. As a result, the movable member 120 is gradually displaced from the first position toward the second position while weakening the acceleration.

(d) is a state in which the movable member 120 has reached the second position. As the magnetic flux density of the movable member 120 further increases, the driving force of the movable member 120 decreases, and the movable member 120 is held at the second position.

The displacement of the movable member 120 from the second position to the first position is the same as the displacement from the first position to the second position, except that the direction of displacement is opposite. Therefore, description thereof is omitted.

(Comparison with conventional configuration)
A two-dot chain line L4 shown in FIG. 2 represents, for comparison, the propulsive force in the case where the movable member has a magnet (mover side magnet) (configuration of the movable element of the clutch of Patent Document 3 described above). In this case, the propulsive force becomes maximum near the displacement destination, and its magnitude is also large. Therefore, the force of displacement of the movable member is too strong, and a loud impact sound is generated.

On the other hand, in this actuator 100, as indicated by lines L2 and L3, the driving force decreases in the latter half of the displacement and becomes smaller as the target position is approached, so that the movable member can be displaced with moderate momentum. When the actuator 100 and the comparative object were compared under the same conditions, a decrease in propulsive force of about 50% was observed at maximum. Therefore, with this actuator 100, impact noise can be effectively suppressed.

Moreover, when the movable member 120 has the mover-side magnet as in the comparative example, the mover-side magnet may come off when the movable member 120 rotates at high speed. On the other hand, this actuator 100 does not have a mover-side magnet, so there is no such possibility. Therefore, it can rotate at high speed, which is advantageous for dehydration, for example.

In addition, the actuator 100 is also advantageous in that it is easy to manufacture when compared with the comparative object. That is, these magnets are typically magnetized after the hard magnetic material has been assembled, rather than after the magnet has been assembled. If the magnets are assembled first, foreign matter such as iron powder may adhere to the magnets and their surroundings during the subsequent manufacturing process, making manufacturing difficult due to the effects of magnetism.

It is difficult to magnetize the mover-side magnets for comparison after assembly, but the magnets 114a and 114b of this actuator 100 are relatively easy to magnetize after assembly. Therefore, this actuator 100 has the advantage of being easy to manufacture. With this actuator 100, the core (iron core), which has high machining accuracy, serves as the main magnetic path for the air gap surface. The resulting iron loss can also be suppressed.

Furthermore, in this actuator 100, it is difficult for the magnetic flux to flow in the direction of demagnetizing the magnets 114a and 114b (see magnetic flux distribution in FIG. 3). Therefore, since the demagnetization resistance may be low, inexpensive magnets can be used for these magnets 114a and 114b. In addition, since the movable member 120 can be composed only of thin iron plates, the weight of the movable member 120 can be reduced. Less energy is required to displace the movable member 120, and noise can be reduced.

<Drive unit for washing machine>
Next, an application example (driving unit for a washing machine) of the actuator 100 described above will be described.

Specifically, the actuator 100 is used for the clutch 54 of the drive unit 5, which will be described later. A stator 5432 (fixed member 110) and a mover 5431 (movable member 120) of the clutch 54 (actuator 100) have circular shapes with the same center and are formed in an annular shape. The wire group then constitutes a clutch coil 5432a wound around its center.

(washing machine)
FIG. 4 illustrates the washing machine 1 to which the actuator 100 is applied. This washing machine 1 is a so-called drum-type washing machine. The washing machine 1 is a so-called fully automatic washing machine, and is configured to automatically perform a series of washing processes including washing, rinsing, dehydration, and the like.

The washing machine 1 mainly includes a housing 2, a tub 3 (stationary tub), a drum 4 (rotating tub), a drive unit 5, a controller 6 (control device), and the like.

The housing 2 is a box-shaped container made up of panels and frames, and constitutes an outer shell of the washing machine 1 . A circular loading slot 2a is formed on the front surface of the housing 2 for loading and unloading laundry. A door 2b having a transparent window is attached to the inlet 2a. The inlet 2a is opened and closed by a door 2b. Above the input port 2a in the housing 2, an operation unit 7 having switches and the like operated by the user is installed.

(Tab 3)
Inside the housing 2, a tab 3 is installed that communicates with the inlet 2a. The tub 3 is a bottomed cylindrical container capable of storing water, and its opening is connected to the inlet 2a. The tab 3 is supported by a damper (not shown) provided inside the housing 2 so as to be stable in a posture in which the center line J thereof is slightly inclined upward toward the front.

Above the tub 3, a water supply device 8 including a water supply pipe 8a, a water supply valve 8b, a drug injection device 8c and the like is provided. An upstream end of the water supply pipe 8a protrudes outside the washing machine 1 and is connected to a water supply source (not shown). A downstream end of the water supply pipe 8 a is connected to a water supply port 3 a opening at the top of the tub 3 . The water supply valve 8b and the medicine injection device 8c are installed in the middle of the water supply pipe 8a in this order from the upstream side.

The chemical injection device 8c accommodates chemicals such as detergents and softeners, and mixes these chemicals with the water to be supplied, thereby injecting them into the tub 3 . A drain port 3b is provided at the bottom of the tub 3. As shown in FIG. The drain port 3b is connected to a drain pump 9. As shown in FIG. The drain pump 9 drains unnecessary water accumulated in the tub 3 to the outside of the washing machine 1 through a drain pipe 9a.

(drum 4)
The drum 4 is a cylindrical container having a diameter slightly smaller than that of the tub 3 and is housed in the tub 3 with the center line J aligned with the tub 3 . A circular opening 4a facing the inlet 2a is formed in the front portion of the drum 4. As shown in FIG. Laundry is put into the drum 4 through the inlet 2a and the circular opening 4a.

A large number of dewatering holes 4b are formed along the entire circumference of the drum 4 (only some of them are shown in FIG. 4). In addition, lifters 4c for stirring are attached to a plurality of locations inside the side portion. A front portion of the drum 4 is rotatably supported by the inlet 2a.

A drive unit 5 is attached to the bottom of the tub 3 . 5 and 6, the drive unit 5 is composed of a shaft 50, a unit base 51, a motor 52, and the like. The shaft 50 passes through the rear portion of the tab 3 and protrudes inside the tab 3 . The tip of the shaft 50 is fixed to the center of the bottom of the drum 4 .

That is, the rear portion of the drum 4 is supported by a shaft 50, and the drive unit 5 directly drives the drum 4 (corresponding to a so-called direct drive system). Thereby, the drum 4 is rotated around the center line J by driving the motor 52 .

The center line J corresponds to the rotation axis (rotation axis J). Since this washing machine 1 is of a drum type, the rotation axis J is arranged so as to extend in a direction inclined with respect to the horizontal direction or in a substantially horizontal direction.

The controller 6 is installed on the top of the housing 2 . The controller 6 is composed of hardware such as a CPU and memory, and software such as control programs and various data. Controller 6 comprehensively controls the operation of washing machine 1 .

An inverter 10 that receives power from an external power supply is installed inside the housing 2 . Inverter 10 is electrically connected to controller 6 and drive unit 5 . The drive unit 5 is driven by the controller 6 controlling the inverter 10 . The drum 4 is thereby rotated.

<Drive unit 5>
As described above, the drive unit 5 is composed of the shaft 50, the unit base 51, the motor 52, and the like. FIG. 7 shows a schematic cross-sectional view of a main part of the drive unit 5. As shown in FIG.

As shown in FIG. 6 , the unit base 51 is made of a substantially disk-shaped metal or resin member attached to the bottom of the tab 3 . A cylindrical shaft insertion hole 511 extending along the center line J is formed in the central portion of the unit base 51 . A pair of ball bearings (a main bearing 512M and a sub-bearing 512S) are attached to both ends of the shaft insertion hole 511 . 6 shows the shaft 50 and the sub-bearing 512S assembled to the motor 52. As shown in FIG. The motor 52 is attached to the back side of the unit base 51 .

The shaft 50 is made of a cylindrical metal member with a diameter smaller than that of the shaft insertion hole 511 . The shaft 50 is inserted into the shaft insertion hole 511 with its tip protruding from the shaft insertion hole 511 . The shaft 50 is supported by the unit base 51 via a pair of ball bearings 512M, 512S. Thereby, the shaft 50 is rotatable around the rotation axis J. As shown in FIG.

The structure of the motor 52 is devised so as to be suitable for driving the washing machine 1 . That is, the washing machine 1 performs washing, rinsing, and spin-drying processes. Therefore, the motor 52 is required to have a high torque output at low speed rotation and a low torque output at high speed rotation.

In general, there is a method in which a speed reducer and a clutch are interposed between the drum and the motor to indirectly rotate the drum (indirect drive method), and a method in which the motor is driven by inverter control to directly rotate the drum. A rotating method (direct drive method) is used.

On the other hand, the drive unit 5 is devised so as to eliminate the shortcomings of each system by efficiently combining the indirect drive system and the direct drive system. That is, the washing machine 1 can realize a compact size with a large washing capacity, low noise, and energy saving.

Specifically, by efficiently incorporating a speed reducer 53 and a clutch 54 interposed between the shaft 50 and the motor 52 into the motor 52 that rotates the single shaft 50 that is the output shaft, these are integrated. is configured to As a result, the motor 52, the speed reducer 53, and the clutch 54 are arranged in a line in a direction substantially perpendicular to the rotation axis J. As shown in FIG. These structures will be described in detail below.

(Base end portion 50a of shaft 50)
As shown in FIG. 7, the base end 50a of the shaft 50 protrudes from the sub-bearing 512S. A screw hole 501 extending along the center line J is formed in the base end portion 50a of the shaft 50 . Serrations extending along the center line J are formed on the outer peripheral surface of the base end portion 50a of the shaft 50 (see FIG. 10). A bolt 503 is fastened to the screw hole 501 via a stopper 502 . By doing so, a main frame 5311 of a carrier 531, which will be described later, is fixed to the base end portion 50a of the shaft 50. As shown in FIG.

(motor 52)
The motor 52 has a rotor 521 and a stator 522 . The motor 52 is a so-called outer rotor type in which the rotor 521 is positioned outside the stator 522 .

As shown in FIG. 8, the rotor 521 is composed of a rotor case 5211, a plurality of magnets 5212, and the like. The rotor case 5211 is composed of a bottomed cylindrical member arranged so that its center coincides with the rotation axis J. As shown in FIG. The rotor case 5211 has a disk-shaped bottom wall 5211a with a round hole at the center, and a cylindrical peripheral wall 5211b continuous around the bottom wall 5211a. Note that the bottom wall 5211a may consist of multiple articles or one article. The rotor case 5211 has a shallow bottom (thickness is small), and the height of the peripheral wall 5211b is smaller than the radius of the bottom wall 5211a.

A cylindrical shaft support portion 5211c facing the peripheral wall 5211b is formed around the round hole opened at the center of the bottom wall 5211a. A gear is formed on the outer peripheral surface of the shaft support portion 5211c, and the shaft support portion 5211c also serves as a sun gear (sun gear 5211c), which will be described later.

A cylindrical sintered oil-impregnated bearing 5213 is fixed inside the shaft support portion 5211c. The shaft support 5211c is slidably supported by the shaft 50 (specifically, the main frame 5311 fixed to the shaft 50) through the sintered oil-impregnated bearing 5213. As shown in FIG. Thereby, the rotor case 5211 is rotatable with respect to the shaft 50 . The sintered oil-impregnated bearing 5213 constitutes a rotor bearing portion.

Each magnet 5212 consists of a rectangular permanent magnet 114 bent into an arc. Each magnet 5212 is fixed to the inner surface of the peripheral wall 5211b of the rotor case 5211 so as to be arranged in series in the circumferential direction. Each magnet 5212 constitutes the magnetic poles of the rotor 521, and is arranged so that S poles and N poles are alternately arranged.

As shown in FIG. 9, the stator 522 is made of an annular member and has an annular core portion 522a and a plurality of tooth portions 522b radially protruding outward from the core portion 522a. The stator 522 is fixed to the unit base 51 via a fixed flange portion 522c provided inside the core portion 522a. Stator 522 is housed in rotor case 5211 .

The core portion 522a and each tooth portion 522b are configured by covering the surface of a magnetic metal stator core 5221 with an insulating insulator. Although not shown, a plurality of coils are formed around each tooth portion 522b by winding conductive wires in a predetermined order. Part of the stator core 5221 is exposed on the end face of each tooth portion 522b located on the outer peripheral portion of the stator 522. As shown in FIG. The exposed portions of these stator cores 5221 are radially opposed to the magnets 5212 of the rotor 521 with a predetermined gap G therebetween.

A plurality of coils constitute a three-phase coil group consisting of U, V, and W. A controller 6 controls an inverter 10 to supply an alternating current to each of these coil groups while shifting the phase. By doing so, a magnetic field is formed between each coil group and the magnetic poles of the rotor 521 . The rotor 521 rotates around the rotation axis J due to the action of the magnetic force.

(Reducer 53)
The speed reducer 53 is arranged around the shaft support portion 5211c. The speed reducer 53 is housed in the rotor case 5211 . FIG. 10 shows the speed reducer 53 portion. The speed reducer 53 is a speed reducer using a so-called planetary gear mechanism, and includes a carrier 531, a sun gear 5211c, a plurality of (four in the figure) planetary gears 533, an internal gear 534, and the like.

The carrier 531 has a mainframe 5311 and a subframe 5312 . The subframe 5312 consists of an annular member having four lower bearing recesses 5312a. The subframe 5312 is mounted on the rotor case 5211 via an annular guide plate 535 .

A ring-shaped sliding member 536 is fixed inside the guide plate 535 . The guide plate 535 is rotatably mounted on the bottom wall 5211a of the rotor case 5211 with a sliding member 536 interposed between it and the shaft support 5211c.

The main frame 5311 has a base portion 5311a having a shallow cylindrical shape with a bottom, and a cylindrical shaft stop portion 5311b projecting from the central portion of the base portion 5311a to the rear side thereof. The rear surface of the base portion 5311a is arranged to face the subframe 5312 . A plurality of upper bearing recesses 5311c facing each of the lower bearing recesses 5312a are formed on the back surface of the base portion 5311a.

A serration that fits into the base end portion 50a of the shaft 50 is formed on the inner peripheral surface of the shaft stop portion 5311b. By inserting the base end portion 50a of the shaft 50 into the shaft stop portion 5311b, the main frame 5311 is fixed to the shaft 50 in a non-rotatable state. Around the shaft stop portion 5311b, as described above, the shaft support portion 5211c of the rotor 521 is supported via the sintered oil-impregnated bearing 5213 constituting the rotor bearing portion. The shaft support portion 5211c constitutes a sun gear that rotates about the rotation axis J. As shown in FIG.

The internal gear 534 is made of a substantially cylindrical member having a larger diameter than the sun gear 5211c. A gear portion 534 a is provided below the inner peripheral surface of the internal gear 534 . Gear teeth are formed over the entire circumference of the gear portion 534a. A plurality of inner slide guides 534b, which are linear projections extending in the direction of the rotation axis, are formed on the outer peripheral surface of the internal gear 534 at regular intervals over the entire circumference. These inner slide guides 534b will be separately described later.

The internal gear 534 is arranged around the rotation axis J around the sun gear 5211c. A lower portion of the internal gear 534 is arranged on the guide plate 535 . A ring-shaped sliding member 537 is fixed inside the upper portion of the internal gear 534 (see FIG. 7). The carrier 531 (main frame 5311 ) is rotatably supported by the internal gear 534 via the sliding member 537 .

Each planetary gear 533 is rotatably supported by the carrier 531 and arranged between the sun gear 5211c and the internal gear 534 so as to mesh with them.

Each planetary gear 533 consists of a small-diameter gear member. A pin hole is formed through the center of each planetary gear 533 . Both ends of the pin 5331 inserted into the pin hole are pivotally supported by the upper bearing recess 5311c of the main frame 5311 and the lower bearing recess 5312a of the sub-frame 5312 . Gear teeth are formed on the outer peripheral surface of each planetary gear 533 over the entire circumference. This gear tooth meshes with both the sun gear 5211 c and the internal gear 534 .

Therefore, when the sun gear 5211c rotates at a predetermined speed with the internal gear 534 fixed (unrotatable), each planetary gear 533 rotates around the sun gear 5211c. Thereby, carrier 531 and shaft 50 rotate in a decelerated state.

(clutch 54)
The clutch 54 is arranged around the speed reducer 53 . Clutch 54 is housed in rotor case 5211 . 11, 12 and 13 show portions of the speed reducer 53 and the clutch 54. FIG. The clutch 54 has a slider 541 (movable portion), rotor-side and stator-side lock claws 542R and 542S (fixed portions), and a clutch driver 543 (drive portion).

Clutch driver 543 has mover 5431 and stator 5432 . These mover 5431 and stator 5432 are configured using the actuator 100 described above.

The slider 541 is made of a cylindrical member having a diameter larger than that of the internal gear 534 . As shown in FIG. 11, a plurality of outer slide guides 541a, which are linear projections extending in the rotation axis direction, are formed on the inner peripheral surface of the slider 541 at regular intervals over the entire circumference. These outer slide guides 541 a are configured to mesh with a plurality of inner slide guides 534 b formed on the outer peripheral surface of the internal gear 534 .

The slider 541 is arranged around the internal gear 534 with each of its outer slide guides 541a meshing with each of its inner slide guides 534b. Thereby, the slider 541 is slidable in the rotation axis direction.

A pair of engaging claws 5411R and 5411S, which are rotor-side and stator-side engaging claws, are formed on the outer peripheral surface of the slider 541. As shown in FIG. These engaging claws 5411R and 5411S are composed of a plurality of protrusions (movable side protrusions) protruding in the rotation axis direction, and are formed on the outer peripheral surface of the slider 541 at regular intervals over the entire circumference. The rotor-side engaging claw 5411R is arranged at the lower end of the slider 541, and each protrusion protrudes downward. The stator-side engaging claw 5411S is arranged at the upper end portion of the slider 541, and each protrusion protrudes upward.

A mover accommodating portion 541b for accommodating the mover 5431 is formed between the rotor-side and stator-side engaging claws 5411R and 5411S on the outer peripheral surface of the slider 541. As shown in FIG.

As shown in FIG. 13 , the rotor-side lock claw 542R is provided on an annular member 544 attached to the rotor case 5211 . The rotor-side lock claw 542R is composed of a plurality of projections (fixed-side projections) protruding in the rotation axis direction at equal intervals over the entire circumference. These projections protrude upward. Although not shown, these protrusions can be formed simultaneously with other constituent parts or formed integrally with the rotor case 5211 when integrally molding the rotor.

A stator-side locking claw 542 S is provided on an annular member 545 attached to the stator 522 . The stator-side lock claw 542S is composed of a plurality of projections (fixed-side projections) protruding in the rotation axis direction at equal intervals over the entire circumference. These protrusions protrude downward. Also, these projections can be configured integrally with the insulator.

The rotor-side lock claw 542R and the stator-side lock claw 542S are arranged so as to face each other at positions separated in the rotation axis direction. The rotor-side locking claw 542R is configured to mesh with the rotor-side engaging claw 5411R, and the stator-side locking claw 542S is configured to mesh with the stator-side engaging claw 5411S.

The space between the rotor-side lock claw 542R and the stator-side lock claw 542S is set larger than the space between the rotor-side engagement claw 5411R and the stator-side engagement claw 5411S. Therefore, when the rotor-side lock claw 542R engages and connects with the rotor-side engagement claw 5411R, the stator-side lock claw 542S does not mesh with the stator-side engagement claw 5411S. When the stator-side locking claw 542S is meshed with the stator-side engaging claw 5411S and connected, the rotor-side locking claw 542R does not mesh with the rotor-side engaging claw 5411R.

As shown in FIG. 12 , the mover 5431 of the clutch driver 543 has a moveable member 120 . The movable member 120 is installed in the mover housing portion 541b.

As shown in FIG. 13, the stator 5432 of the clutch driver 543 has a fixed member 110. As shown in FIG. That is, it is composed of a clutch coil 5432a, an inner core 112, an outer core 111, two magnets 114a and 114b, and the like.

The outer core 111 is composed of a pair of upper and lower annular holders 5432c. Holder 5432 c is fixed to stator 522 . Both the inner core 112 and the two magnets 114a and 114b are annular. The movable member 120 is configured to face the fixed member 110 with a small gap G in the radial direction while being positioned inside the fixed member 110 .

The controller 6 controls energization of the clutch coil 5432a. The controller 6 supplies the clutch coil 5432a with a switching current, that is, a current having opposite energization directions, thereby linearly displacing the movable member 120 with respect to the fixed member 110 . As a result, the controller 6 performs processing (switching processing) for sliding the slider 541 in one direction of the rotation axis.

As a result, as shown in FIG. 14, a first mode in which the stator-side engaging claw 5411S engages with the stator-side locking claw 542S and a second mode in which the rotor-side engaging claw 5411R engages with the rotor-side locking claw 542R are performed. and switch to.

In the first mode, internal gear 534 is supported by stator 522 via slider 541 . Rotation of rotor 521 and sun gear 5211 c is thereby transmitted to shaft 50 and carrier 531 via speed reducer 53 . Therefore, the drive unit 5 outputs a rotational force with low rotation and high torque.

On the other hand, in the second mode, the internal gear 534 is supported by the rotor 521 via the slider 541 . Rotation of the rotor 521 and the sun gear 5211 c is thereby transmitted to the shaft 50 and the carrier 531 without going through the speed reducer 53 .

That is, since the rotor 521, the sun gear 5211c, and the internal gear 534 rotate together, the planetary gears 533 do not rotate. As a result, shaft 50 and carrier 531 also rotate together. Therefore, the drive unit 5 outputs a rotational force with high rotation and low torque.

Thus, according to the drive unit 5, the motor 52, the speed reducer 53 and the clutch 54 are arranged in a row in a direction substantially perpendicular to the rotation axis J. 54 are efficiently incorporated, and they are integrally constructed. By switching the clutch 54 , it is possible to output a low-rotation, high-torque rotational force and a low-torque, high-rotational rotational force through the single shaft 50 . Also, in both the first mode and the second mode having different outputs, the rotational speed and torque of the motor 52 can be set to relatively close values, so the motor efficiency can be optimized.

Therefore, this drive unit 5 is compact in size and can output a torque suitable for a washing machine. The drive unit 5 is suitable for washing machines.

(Operation of washing machine 1)
FIG. 15A shows a basic operation example of the washing machine 1. FIG.

When the washing machine 1 is operated, first, laundry is put into the drum 4 (step S1). In the case of this washing machine 1, at that time, the detergent or the like is also put into the chemical injection device 8c. Then, an instruction to start washing is input to the controller 6 by operating the operation unit 7 (Yes in step S2). The controller 6 thereby automatically initiates a series of washing processes, such as washing, rinsing, and spin-drying.

Prior to the washing process, the controller 6 measures the weight of the laundry in order to set the amount of water supply (step S3). The controller 6 sets an appropriate amount of water supply based on the measured weight of the laundry (step S4).

After setting the water supply amount, the controller 6 starts the washing process (step S5). When the washing process starts, the controller 6 controls the water supply valve 8b to supply the tub 3 with a set amount of water. At that time, the detergent contained in the chemical injection device 8c is injected into the tub 3 together with the supplied water.

The controller 6 then drives the drive unit 5 to initiate rotation of the drum 4, with the controller 6 prior to rotating the drum 4 through a washing or rinsing process, as shown in FIG. 15B. It is determined whether or not (step S10). As a result, if it is a washing or rinsing process, the controller 6 controls the clutch 54 to switch to the first mode (step S11). If it is not a washing or rinsing process, that is, if it is a dewatering process, the controller 6 controls the clutch 54 to switch to the second mode (step S12).

Since this is the washing process, the controller 6 switches the clutch 54 to the first mode. As a result, the drive unit 5 outputs a low-speed, high-torque rotational force. Therefore, the relatively heavy drum 4 can be efficiently rotated at a low speed.

When the washing process ends, the controller 6 starts the rinsing process (step S6). In the rinsing process, the wash water accumulated in the tub 3 is drained by driving the drain pump 9 . Next, the controller 6 performs water supply and agitation in the same manner as in the washing process.

In the rinsing process, the drive unit 5 is driven while the clutch 54 is maintained in the first mode.

After the rinsing process is completed, the controller 6 executes the dehydration process (step S7). In the dewatering process, the drum 4 is rotated at high speed for a predetermined time. Therefore, the controller 6 switches the clutch 54 to the second mode prior to the dewatering process. In the second mode, it is possible to output rotational force with high rotation and low torque. Therefore, the relatively light drum 4 can be efficiently rotated at high speed.

The laundry sticks to the inner surface of the drum 4 by centrifugal force. Water contained in the laundry flows out of the drum 4 . The laundry is thereby dehydrated.

Water accumulated in the tub 3 due to dehydration is discharged by driving the drain pump 9 . When the dehydration process is finished, the completion of washing is notified by sounding a predetermined buzzer, etc., and the operation of the washing machine 1 is finished.

(Impact noise suppression control by drive unit)
In this washing machine 1, the control is devised so that impact noise can be suppressed by using the clutch driver 543, more specifically, the structure of the actuator 100. FIG.

Specifically, the controller 6 executes switching processing, and executes processing (braking processing) for stopping supply of the switching current to the clutch 54 immediately before the slider 541 is coupled to the lock claws 542R and 542S. .

FIG. 16 shows a time chart of the braking process. A graph G1 represents changes in the current flowing through the clutch 54 . A graph G2 represents the speed of the slider 541 . A graph G3 represents the driving force of the slider 541 . MP is a target position at which the lock claws 542R, 542S and the engagement claws 5411R, 5411S are engaged (corresponding to the first position and the second position).

At a predetermined timing before the slider 541 reaches the target position MP, the controller 6 de-energizes the clutch coil 5432a. Even when the energization of the clutch coil 5432a is turned off, the slider 541 is displaced by the inertia and the magnetic force of the magnet. When the power to the clutch coil 5432a is turned off, the speed of the slider 541 is suppressed due to the rapid decrease in propulsive force and braking by the regenerative current. As a result, impact noise can be suppressed.

Since the supply of the switching current to the clutch 54 is simply stopped, the control can be easily performed. Impulsive noise can be effectively suppressed simply by adjusting the timing of stopping.

(Clutch switching determination control by drive unit)
When the switching process fails, such as when the clutch 54 is not switched or when it is switched but is not in an appropriate position, when the motor 52 is driven in that state, troubles such as generation of abnormal noise and damage to the clutch 54 occur. Therefore, it is preferable to determine the success or failure of each switching process.

On the other hand, in this washing machine, the clutch driver 543, more specifically, the structure of the actuator 100 is used to determine the success or failure of the switching of the clutch 54, so that the control is devised.

Specifically, the controller 6 compares the current flowing through the clutch coil 5432a immediately after the switching process is executed with a predetermined determination value. By doing so, the controller 6 executes a process of determining whether the switching of the clutch 54 has been successful (switching determination process).

When the current flows in the same direction before and after the switching process, the magnetic flux density between the movable member 120 and the fixed member 110 is different. This creates a difference in inductance and changes the transient response of the current. The success or failure of the switching process can be determined based on the change.

Specifically, as shown in (b) of FIG. 3 , the magnetic flux generated by the current in the movable member 120 acts to weaken the magnetic flux of the magnet 114 when energized before the switching process. Therefore, the magnetic flux density is low. On the other hand, as shown in (d) of FIG. 3, the direction of the magnetic flux of the current and the direction of the magnetic flux of the magnet 114 are the same at the time of energization after the switching process. Therefore, the magnetic flux density is high.

As a result, a difference occurs in the inductance before and after the switching process, resulting in a change in the transient response of the current. Based on the change, the controller 6 determines the success or failure of the switching process.

Incidentally, the determination value may be set to a predetermined value in advance. is preferably set as the judgment value.

External factors such as the ambient temperature and the state of use of the clutch 54 may affect the determination value. On the other hand, if the determination value is set by such a method each time the switching determination process is performed, such an influence can be eliminated. Therefore, the switching determination process can be performed with high accuracy.

Then, the switching determination process may be executed by comparing the determination value with the current flowing through the clutch coil 5432a based on the voltage command value for determination immediately after the switching process is performed.

FIG. 17 shows an example of such switching determination processing. When the controller 6 starts the switching process, immediately before starting the switching process, based on a predetermined judgment voltage command value (a voltage command value for flowing a current having a magnitude that does not affect the state of the clutch 54), the clutch coil 5432a energize. By doing so, the current value Ia flowing through the clutch coil 5432a is acquired, and the current value Ia is set as the determination value (step S20).

Specifically, a predetermined voltage is applied for a short period of several milliseconds during which the clutch 54 cannot respond. For example, the voltage may be applied by PWM modulated with a carrier frequency of several tens of kHz using an inverter, or the voltage may be applied by one pulse.

Subsequently, the controller 6 executes switching processing (step S21). Thereby, the slider 541 is displaced and the clutch 54 is switched to either the first mode or the second mode.

The controller 6 energizes the clutch coil 5432a based on the same judgment voltage command value as before, and acquires a current value Ib to be compared (step S22). Then, the controller 6 compares whether the current value Ib is greater than the judgment value Ia (step S23).

As can be seen from the analysis results of FIG. 3, the magnetic field generated by the current flowing through the clutch coil 5432a forms a magnetic path mainly through the iron cores of the movable portion and the fixed portion, which have low magnetic permeability and low magnetic resistance. In the configuration of the present invention, as described above, the magnetic flux density when current is applied in the same direction differs depending on the position of the clutch mover. The soft magnetic material used for the iron core has the property that as the magnetic flux density increases, the magnetic permeability decreases and the magnetic resistance increases. Using this characteristic, the position of the clutch 54 changes the magnetic resistance when a current is applied. Therefore, the impedance of the clutch coil 5432a changes, and the transient response of the current when a voltage is applied changes.

As a result, if the current value Ib is greater than the determination value Ia, it is determined that the switching of the clutch 54 has succeeded (step S24). If the current value Ib is equal to or less than the determination value Ia, switching of the clutch 54 is determined to have failed and is retried (step S25). Here, the case where it is determined to be successful when the current value Ib is greater than the determination value Ia is shown. Become.

If the absolute values (|Ia|, |Ib|) of the current values Ia and Ib are used for determination, it is possible to make a determination based only on the magnitude relationship of the numerical values regardless of the direction in which the current flows. In addition, in order to prevent erroneous determination, the first determination value Ia is multiplied by a coefficient such as "|Ib|>|Ia|× coefficient", and the determination value Ib obtained later does not exceed this value. and may not be determined to be successful.

According to the drive unit 5, the success or failure of the switching of the clutch 54 can be determined appropriately each time. Therefore, troubles caused by poor switching of the clutch 54 can be suppressed.

Note that the technology disclosed is not limited to the above-described embodiments, and includes various other configurations.

For example, in the embodiment, the magnets are arranged so that the north poles of the magnets face each other, but the magnets may be arranged so that the south poles of the magnets face each other. By reversing the energizing direction of the coil, the same effect as the embodiment can be obtained. Moreover, the number of magnets of the fixing member 110 may be three or more. The movable member 120 may be arranged inside the fixed member 110 or may be arranged outside the fixed member 110 .

100 actuator 110 fixed member 112 inner core 113 electric wires 114a, 114b magnet 120 movable member 120a salient pole core 120b connecting core 1 washing machine 3 tab (fixed tub)
4 drum (rotating tank)
5 drive unit 6 controller (control device)
52 Motor 53 Reduction gear 533 Planetary gear 534 Internal gear 54 Clutch 541 Slider (movable part)
5411R Rotor-side engagement claw 5411S Stator-side engagement claw 542R Rotor-side lock claw (fixed portion)
542S Stator-side lock claw (fixed part)
543 Clutch driver (drive unit)
5431 mover 5432 stator 5432a clutch coil J center line (rotating shaft)
G gap

Claims (10)

An actuator comprising a fixed member that is fixed and used, and a movable member that reciprocates along the fixed member in a predetermined first direction,
The fixing member is
electric wires spaced apart in a second direction intersecting the first direction and extending in a direction crossing both the first direction and the second direction;
two magnets arranged between the electric wire and the movable member in a state of being aligned in the first direction and arranged such that the same magnetic poles of each magnet face the first direction;
has
The movable member is
two salient pole cores that are arranged side by side in the first direction and whose tip portions are capable of facing the two magnets in close proximity;
a connecting core that connects the proximal end portions of the two salient pole cores at a position away from the two magnets;
has
An actuator in which the movable member reciprocates by switching the energization direction of the electric wire. The actuator of claim 1, wherein
The movable member is integrally formed using a plate-shaped soft magnetic material,
An actuator, wherein each tip portion of the salient pole core is provided with a flange projecting in the opposite direction to the first direction. The actuator according to claim 1 or 2,
the fixed member and the movable member have circular shapes with their centers aligned;
An actuator, wherein the wire constitutes a coil wound around the center. The actuator according to claim 3, wherein
The actuator, wherein the movable member is arranged inside the fixed member. The actuator according to claim 3, wherein
The actuator, wherein the movable member is arranged outside the fixed member. A drive unit for a washing machine, comprising:
a drive shaft rotatably supported about a rotation axis;
a motor that rotates the drive shaft;
a clutch and a speed reducer interposed between the drive shaft and the motor;
with
The clutch is
a movable part that slides in the direction of the rotation axis in which the rotation axis extends;
a pair of fixing parts positioned apart in the direction of the rotation axis;
a drive unit that switches the connection state of the speed reducer by sliding the movable unit and connecting it to one of the fixed units;
has
A drive unit, wherein the drive section is constructed using the actuator according to any one of claims 3 to 5. A drive unit according to claim 6, wherein
Further comprising a control device for controlling the operation of the clutch,
By supplying a predetermined switching current to the clutch, the control device performs a switching process of connecting the movable portion to one of the fixed portions of the pair of fixed portions, and the movable portion A drive unit that executes braking processing for stopping supply of the switching current to the clutch immediately before being connected to the one fixed portion. A drive unit according to claim 6, wherein
Further comprising a control device for controlling the operation of the clutch,
By supplying a predetermined switching current to the clutch, the control device executes a switching process of connecting the movable part to one of the fixed parts of the pair of fixed parts, and performs the switching process. A drive unit that, when executed, executes switching determination processing that determines whether or not the movable portion is coupled to the one fixed portion. A drive unit according to claim 8, wherein
The drive unit, wherein the control device executes the switching determination process by comparing the current flowing through the coil with a predetermined determination value immediately after the switching process is performed. A drive unit according to claim 9, wherein
Immediately before executing the switching process, the control device sets, as the determination value, a current that flows through the coil by energizing the coil based on a predetermined voltage command value for determination, and the determination value and the A drive unit that executes the switching determination process by comparing the current flowing through the coil based on the voltage command value for determination immediately after the switching process is executed.

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