JP2008018131A - Electric washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To gain large braking torque while protecting overvoltage when braking. <P>SOLUTION: The washing machine has an electric motor 40 for performing rotary driving of a drum 71, a water supply means 82, and a heat generating means 60 for heating water. During a braking period, at least a part of kinetic energy of the drum 71 is supplied to the heat generating means 60, and the large braking torque is obtained. Thus, without newly providing a large expensive discharge circuit, large kinetic energy is absorbed when braking, and large braking torque is generated to perform quick braking possible. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric washing machine used in general households.

  Conventionally, this type of electric washing machine has a DC power source forming means for forming a DC power source from an AC power source, and an inverter circuit that receives the output and is connected to a winding of a brushless motor, and brakes at the end of dehydration In some cases, regenerative power adjusting means for adjusting the regenerative power generated by the brushless motor and brake control means for controlling the regenerative power within a predetermined range are provided (for example, see Patent Document 1).

  FIG. 7 shows a block diagram of a conventional power generator described in Patent Document 1. In FIG. As shown in FIG. 7, in order to form a DC power source from the AC power source 1, a DC power source forming means 6 constituted by a reactor, a rectifier, and electrolytic capacitors 4 and 5 for performing voltage doubler rectification is provided. And an inverter circuit 15 connected to the windings 11, 12, and 13 of the brushless motor 10 and a voltage detection means 19 configured by resistors 17 and 18 for detecting a DC voltage.

The brake control means and the brake control means are realized in a form programmed in the microcomputer 21, and a drive circuit is provided so that the DC voltage does not become excessive with respect to the breakdown voltage of each component during braking at the end of dehydration. The signal to 22 is controlled.
JP 2003-225493 A

  However, in the above-described conventional configuration, as a result of controlling so that the direct current (bus) voltage does not become excessive by regenerative electric power generated by converting absorbed kinetic energy into electric energy during braking, braking torque during braking is obtained. When using a discharge circuit for consuming electric power converted to DC, the shape tends to be large and the cost tends to be high, and a short circuit that is not converted to DC voltage Even if braking is performed, power absorption is limited to the inside of the motor and the inverter circuit, so it is still difficult to make the brake torque sufficiently large, and it takes a long time to stop the dehydration rotation. It had the problem of becoming.

  The present invention solves the above-described problems, and an object thereof is to realize an electric washing machine that absorbs kinetic energy by generating a large braking torque during braking.

  In order to solve the above-described problems, an electric washing machine of the present invention includes a drum for storing clothes, an electric motor for rotationally driving the drum, water supply means for supplying water into the drum, and water in the drum. A heating unit for heating is provided, and at least a part of the kinetic energy of the drum is supplied to the heating unit during a braking period in which the rotation of the drum is suppressed.

  This makes it possible to absorb a large amount of kinetic energy during braking, generate a large braking torque, and quickly apply a brake without newly providing a large and expensive discharge circuit.

  According to the present invention, a large braking torque can be obtained during braking.

  1st invention has the drum which accommodates clothing, the electric motor which rotationally drives the drum, the water supply means which supplies water in the drum, and the heat generation means which heats the water in the drum, The drum By supplying at least a part of the kinetic energy of the drum to the heat generating means during the braking period to suppress the rotation of the drum, the kinetic energy can be effectively absorbed by the heat generating means during braking, and a large braking torque So that the brakes act quickly.

  According to a second aspect of the present invention, there is provided a drum for storing clothes, an electric motor for rotationally driving the drum, and heat generating means for heating air in the drum, and the movement of the drum during a brake period for suppressing the rotation of the drum. By supplying at least a part of the energy to the heat generating means, the kinetic energy can also be effectively absorbed by the heat generating means during braking, a large braking torque can be obtained, and the brake operates quickly. To be.

  In particular, in addition to the configuration of the first invention or the second invention, the third invention is a rectifier circuit that inputs an AC power supply and outputs a DC voltage, and an inverter circuit that is connected to the rectifier circuit and drives an electric motor. The inverter circuit regenerates the electric power from the electric motor at the input during the brake period, and supplies current to the heat generating means connected to the input, thereby preventing an adverse effect such as an overvoltage of the DC voltage portion. Sometimes the kinetic energy can be effectively absorbed by the heat generating means, a large braking torque can be obtained, and the brake can act quickly.

  In particular, the fourth invention has a bidirectional power conversion circuit for performing bidirectional power conversion provided between the AC power source and the electric motor in addition to the configuration of the first invention or the second invention, and in the braking period. The bidirectional power conversion circuit regenerates the electric power from the electric motor to the input, and supplies current to the heat generating means connected to the input, so that the number of power conversion stages is minimized, and at the time of braking The kinetic energy can be effectively absorbed by the heat generating means, a large braking torque can be obtained, and the brake can act quickly.

  In particular, the fifth invention has input power detection means for detecting input power from an AC power supply in addition to the configuration of the fourth invention, and the bidirectional power conversion circuit has a negative output from the input power detection means. By performing the operation during the braking period within a range that does not occur, a sufficiently large brake torque can be obtained without generating regenerative power to the AC power supply.

  In the sixth aspect of the invention, in particular, the heat generating means according to any one of the first to fifth aspects is constituted by a heat pump having a compressor, thereby exhibiting an energy-saving effect for effective use of electric power. During braking, kinetic energy can be absorbed effectively, a large braking torque can be obtained, and the brake acts quickly.

(Embodiment 1)
FIG. 1 shows a circuit diagram of the electric washing machine according to Embodiment 1 of the present invention. In FIG. 1, a 100 V, 50 Hz or 60 Hz AC power supply 31 is provided with a reactor 32, a full-wave rectifier 33 incorporating four diodes, and a rectifier circuit 36 having electrolytic capacitors 34, 35. A rectifier circuit 36 that outputs a DC voltage VDC of 280 V at no load by voltage doubler rectification is configured.

  The electric motor 40 has three-phase windings 41, 42, and 43, and an inverter circuit 45 that drives the electric motor 40 by supplying an alternating current is a switching element realized by connecting an IGBT and a reverse conducting diode in parallel. What is called a three-phase six-stone full bridge having 50, 51, 52, 53, 54, 55, etc. is operated by receiving a DC voltage VDC from the output of the rectifier circuit 36. Yes.

  The drive circuit 57 performs on / off control of each of the switching elements 50, 51, 52, 53, 54, and 55. Specifically, an on / off signal indicating which switching element is turned on is generated from the control circuit 58. It has become what.

  The heat generating means 60 constituted by an electric heater is connected in series with a switching element 61 constituted by an IGBT, and is connected between the positive and negative input terminals of the inverter circuit 45, and is connected from the control circuit 58 to the drive circuit 63. When an ON signal is input, the switching element 61 is turned ON, VDC is supplied, and heat is generated to heat water.

  FIG. 2 shows a block cross-sectional view of the electric washing machine according to Embodiment 1 of the present invention. In FIG. 2, a garment 70 is housed in a rotatable drum 71, and a drum 71 and a pulsator 72 provided on the bottom surface of the drum 71 are rotationally driven by an electric motor 40. The motor case 40 directly rotates the drum 71 and the pulsator 72 together with a reduction ratio of 1: 6 using gears by the mechanical case 75, or only the pulsator 72 is kept in the stationary state while the drum 71 remains stationary. It is possible to select whether to rotate the shaft at a speed reduced to 1/6 with respect to the shaft, and the former operation is performed during dehydration.

  The drum 71 is housed inside a receiving cylinder 76 that can store water, and is kept suspended by support rods 78 and 79. A water supply means 82 is configured by the water supply valve 80 and the water supply hose 81, and water can be supplied into the drum 71.

  The heat generating means 60 is provided at the bottom of the receiving cylinder 76 and can heat the water in the drum 71. By using high temperature water, the effect of the detergent is increased, and the dirt becomes dirty. It is possible to make an electric washing machine with a high cleaning performance that has a very strong power to drop water.

  A drain valve 85 and a drain hose 86 are also provided at the bottom of the receiving cylinder 76, and the electric motor 40, the water supply valve 80, the drain valve 85, and the heating means 60 are all controlled by connection from an electronic circuit 88. However, the electronic circuit 88 includes the inverter circuit 45, the rectifier circuit 36, and other configurations shown in FIG.

  In the above configuration, after the user puts the clothes 70 and the detergent into the drum 71, when the water supply valve 80 of the water supply means 82 is opened, the drum 71 is filled with water and the switching element 61 is turned on. Thus, the direct current voltage VDC is supplied to the heat generating means 60 to generate heat, and the water in the drum 71 is heated and the temperature is controlled to be higher than the room temperature, thereby increasing the effect of the detergent, and the garment 70 in a short time. It is possible to obtain a high cleaning performance that can remove the dirt.

  After the clothes 70 are rotated together with the detergent by the rotational drive of the pulsator 72 and washing is performed, the drain valve 85 is opened, the water in the drum 71 is drained, the water valve 80 is opened again, and water is supplied. The rinsing operation is performed.

  At this time, in the present embodiment, the DC voltage is not supplied to the heat generating means 60. However, if the effect of rinsing is to be improved, water may be heated again from the heat generating means 60. Absent.

  Further, at the end of washing and rinsing, water is drained from the drain valve 85, where the pulsator 72 and the drum 71 are integrally driven and rotated by the electric motor 40, and the centrifugal force due to high speed rotation of about 1000 revolutions per minute. Acts on the inner side of the drum 71 and is dewatered.

  At the end of the dehydration, a brake period is provided to suppress and stop the rotation of the drum 71 and the pulsator 72 so that a negative torque (torque in the direction opposite to the rotation) is generated from the inverter circuit 45 to the electric motor 40. As a result of the on / off control of each of the switching elements 50, 51, 52, 53, 54, 55, a brake is applied that reduces the speed of the electric motor 71, that is, the rotational speed of the drum 71.

  Here, the kinetic energy of the rotating drum 71 is consumed inside the electric motor 40 and becomes heat, and the inverter circuit 45 receives electric power from the electric motor 40 and regenerates it to the input terminal side. The phenomenon that occurs.

  In the present embodiment, the switching element 61 is turned on during the braking period so that direct-current power is supplied to the heat generating means 60.

  As a result, even if a large braking torque that absorbs the kinetic energy of the drum 71 in a short time is generated, a considerable portion of the absorbed energy is supplied to the heating means 60, and the DC voltage VDC Thus, an effective braking operation can be realized in a short time without worrying about the destruction of the parts due to the excessive rise of the motor.

  In addition, about the brake period, since there is no water of the drum 71, the electric heater which is the heat generating means 60 is in an empty state, but the brake period in a general washing machine is 10 seconds to 20 seconds. In the configuration using the heat generating means 60 having an electric capacity of several hundred watts or more, the heat energy is large, and the rotational energy of the drum 71 including the garment 70 is 5000 joules. Even if all of them are added to the heat generating means 60, the temperature rise of the heat generating means will be within a few tens of degrees and no problem will occur.

(Embodiment 2)
FIG. 3 shows a circuit diagram of the electric washing machine according to Embodiment 2 of the present invention. In FIG. 3, the configurations of the 100 V, 50 Hz, or 60 Hz AC power supply 31 and the electric motor 40 are completely equivalent to those in the first embodiment.

  In the present embodiment, a bidirectional power conversion circuit 90 that performs bidirectional power conversion is provided between the AC power supply 31 and the electric motor 40. The bidirectional power conversion circuit 90 is a six-stone SiC semiconductor element. Bidirectional switching elements 91, 92, 93, 94, 95, 96 are realized by using the bidirectional switching elements 91, 92, 93, 94, 95, 96. Thus, the current in either direction can be turned on and off.

  However, in addition to the bidirectional switching element using SiC, a bidirectional type switching element is equivalently configured by combining a unidirectional switching element such as a bipolar type, MOSFET, or IGBT together with a diode. You may use it.

  The heat generating means 100 is connected in series with the relay 101 and is connected in parallel to the input side of the bidirectional power conversion circuit 90.

  Between the AC power supply 31 and the input terminal of the bidirectional power conversion circuit 90, input power detection means 103 for detecting input power from the AC power supply 31 is provided. The input power detection means 103 is connected to the voltage detection means 104. The current detection means 105 is provided, and voltage output corresponding to the average power of one cycle of the AC power supply 31 is performed.

  The control circuit 110 is slightly different from the case where the inverter circuit 45 of the first embodiment converts the DC voltage into AC and supplies it to the electric motor 40 to realize the rotational drive, so that the rotation of the electric motor 40 is directly performed from the AC power source 31. The AC power necessary for driving is converted and supplied.

  Furthermore, in the bidirectional power conversion circuit 90 of the present embodiment, an on / off command is output to the drive circuit 97 and an on / off signal of the relay 11 is output in order to perform a braking operation. In this embodiment, the signal from the input power detection means 103 is received, and the power from the AC power source 31, that is, the value of power consumption is input.

  FIG. 4 is a block cross-sectional view of the electric washing machine according to Embodiment 2 of the present invention. In FIG. 4, the drum 120 for storing the garment 70 is provided so that the rotation axis is raised by 20 degrees with respect to the horizontal, and is rotated by the electric motor 40. A receiving cylinder 121 for accumulating water is attached to the outside.

  In this embodiment, not only washing but also drying can be performed. Therefore, a cooler 125 for removing moisture from the air in the drum 120, a blower fan 126, and a fan that rotationally drives the blower fan 126. A motor 127 is provided, and the air sent from the blower fan 126 is heated by the heat generating means 100 using an electric heater, becomes air dried at a high temperature, and is returned to the drum 120 again. Thus, during the drying operation, the fan motor 127 is rotationally driven by the fan motor 127, and at the same time, the heat generating means 100 generates heat, whereby the air in the drum 120 is heated.

  The electronic circuit 130 is configured on a printed circuit board as including the electronic components of each part shown in FIG. Water supply means 82 and drain valve 85. About the drainage hose 86, the thing equivalent to Embodiment 1 is used.

  In the above configuration, the electric washing machine of the present embodiment does not have a stirring blade such as a pulsator, but as a result of the drum 120 rotating up to about 120 rotations per minute, a good washing operation is performed. It has become a thing.

  At the time of dehydration, as in the first embodiment, the drum 120 is driven to rotate at a high speed of about 850 to 1500 revolutions per minute by the electric motor 40, so that a powerful dehydration operation by centrifugal force is performed. It has become.

  In the present embodiment, at the end of dehydration, the bidirectional power conversion circuit 90 absorbs the kinetic energy from the electric motor 40 under the control of the drive circuit 97 during the brake period in which the rotation of the drum 120 is suppressed. The regenerative power is supplied to the AC power supply 31.

  At this time, the control circuit 110 turns on the relay 101, and an AC voltage is supplied to the heat generating means 100 realized by an electric heater.

  In general electrical equipment, there is often a problem with respect to power supply to the AC power supply 31, that is, reverse power flow. In this embodiment, the control circuit 110 outputs the output of the input power detection means 103. By operating the bidirectional power conversion circuit 90 during the brake period so as to be in a non-negative range, that is, a condition where no reverse power flow occurs, the kinetic energy of the drum 120 is converted from the electric motor 40 during the brake period. The electric power (regenerative power) is a part, or most of the electric power is supplied to the heat generating means 100 in the form of an alternating current, and the value obtained by subtracting the regenerative power from the power consumption of the heat generating means 100 is the input power. While detecting by the detecting means 103, the operation is performed so that the value does not become negative. The ones over key operation is performed.

  Also in the present embodiment, the temperature rise of the heat generating means 100 during the braking period is in a range where there is no problem even if there is no wind, and thus it is not particularly necessary to drive the blower fan 126. The fan 126 may be rotated, and the amount of power consumed by the fan motor 127 is a condition that the reverse power does not flow even if the regenerative power is larger, and the braking effect can be further enhanced.

(Embodiment 3)
FIG. 5 shows a circuit diagram of the electric washing machine according to Embodiment 3 of the present invention. The electric washing machine of FIG. 5 is an electric washing machine corresponding to the classification of a washing / drying machine that can perform the process up to drying in a fully automatic manner as in the second embodiment.

  In FIG. 5, the AC power supply 31, the electric motor 40, the inverter circuit 45, and the drive circuit 57 have the same configuration as that of the first embodiment.

  As for the rectifier circuit 140, the reactor 32 rectifier 33 and the electrolytic capacitors 34 and 35 are almost equivalent to those of the first embodiment, although there are slight differences in the specifications. The capacitor 141 in the equation is connected to the portion where the DC voltage VDC is output, and the AC power supply 31 is input to output the DC voltage VDC.

  Also in the present embodiment, the inverter circuit 45 is connected to the output of the rectifier circuit 140 to drive the motor 40. At the same time, the inverter circuit 142 that drives the compressor 141 is also connected to the rectifier circuit 140. The inverter circuit 142 that is connected in parallel to the output of the inverter and operates by receiving the direct-current voltage VDC is also used in the form of a three-phase six-stone structure similar to the inverter circuit 45 in terms of internal configuration. Yes.

  Each switching element in the inverter circuit 45 is controlled to be turned on / off by the drive circuit 143. When the control circuit 145 sends a signal to the drive circuits 57 and 143, the rotation of the electric motor 40 and the compressor 141 is performed. The drive is controlled.

  FIG. 6 shows a block cross-sectional view of an electric washing machine according to Embodiment 3 of the present invention. As shown in FIG. 6, the drum 120 has a drum 120 whose rotation axis is inclined by about 20 degrees with respect to the horizontal, and washing and dewatering are performed by rotating the drum 120, and the dried air is passed through the clothing 70 in the drum 120. Thus, the configuration for performing the drying is the same as that of the second embodiment.

  The water supply means 82, the drain valve 85, the drain hose 86, the blower fan 126, and the fan motor 127 are the same as those in the second embodiment. However, the compressor 141 is a component of the heat pump 150, and the refrigerant is used. By compressing, an operation similar to that of a heater that releases heat from the heat generating means 151 to the air is performed. When an alternative chlorofluorocarbon is used, it is also called a condenser.

  However, the type of refrigerant may be other than alternative chlorofluorocarbon, for example, it may be used by compressing carbon dioxide CO2 into a supercritical state. In that case, as the heat generating means 151, A configuration called a gas cooler or the like is adopted.

  On the other hand, the evaporator 152 absorbs heat from the surrounding air in a state where the pressure of the refrigerant is lowered, and the vaporized refrigerant also acts to send the refrigerant again to the compressor 141. A configuration called a circulating refrigeration cycle is used.

  The control circuit 155 includes a microcomputer and the like, and controls each component in order.

  In the configuration as described above, the electric washing machine of the present embodiment can be performed fully automatically from washing to drying as in the second embodiment, thus realizing labor saving that saves the user trouble. In particular, since the heat generating means 151 for heating the air in the drum 120 has the heat pump 150, effective dehumidification is performed when passing through the evaporator 152. The amount of heat generated in the air from the heat generating means 151 can be obtained in a form in which the heat absorbed by the evaporator 152 is added to the electric power supplied to the compressor 141, while suppressing power consumption, Low-humidity air suitable for drying the clothing 70 can be circulated in the drum 120, and an electric washing machine with excellent drying performance and energy saving can be achieved. The things.

  In the present embodiment, as to the operation during dehydration, the drum 70 is rotationally driven by the electric motor 40 and the operation of the compressor 141 is also started.

  At the end of dehydration, during the braking period in which the rotation of the drum 120 is suppressed, the kinetic energy of the drum 120 is converted to the DC side and flows backward, as described in the first embodiment. Since the inverter 142 sharing the DC voltage VDC drives the compressor 141, the kinetic energy rescued from the load by the electric motor 40 is regenerated into electric energy, part of which is a copper loss inside the electric motor 40, Iron loss, mechanical loss, and part of the loss inside the inverter circuit 45, but the other part enters the inverter circuit 142 via the DC voltage VDC, and energy for rotational driving of the compressor 141. In the end, the heat is supplied to the heat generating means 151.

  Therefore, a large brake torque can be supplied from the electric motor 40 without the DC voltage VDC rising excessively, and the time required for braking can also be shortened.

  In the present embodiment, the drum 120 is configured as a drum-type washing machine having a rotation axis inclined about 20 degrees. However, the present invention is not particularly limited to such a configuration. In addition to the electric washing machine having a configuration called a vertical type having an agitating blade such as a pulsator as shown in FIG. 1, heat generating means using a heat pump 150 may be provided.

  Further, the heat generating means 151 using the heat pump 150 is not limited to the configuration for heating the air, but as described in the first embodiment, the heat generating means 151 is supplied to the water so as to heat water necessary for washing. A configuration in which heat is transferred may be used, and various uses of heat from the heat generating means 151 by the heat pump 150 are conceivable.

  If the condition is such that the compressor 141 is operating during the brake period, a large brake torque can be obtained while preventing an excessive increase in the DC voltage VDC, so there is a period during which the heat generating means 151 operates. There is a tendency that the opportunity to shorten the braking period increases.

  In particular, in an electric washing machine having a configuration called a drum type as shown in the second or third embodiment, the left and right alternately rotating drive motions of the washing and rinsing drum 120 are caused not only at the end of dehydration. However, if the brake torque is large, the surroundings of the garment 70 are improved, and there are many cases in which the cleaning performance is improved or the imbalance of the garment 70 is improved. However, the configuration of the present invention that can obtain a large brake torque can be expected to have a great effect as an improvement in performance.

  As described above, the electric washing machine according to the present invention can obtain a large braking torque by supplying at least a part of the kinetic energy of the drum to the heat generating means during the braking period and the electric motor that rotates the drum.

Circuit diagram of electric washing machine in Embodiment 1 of the present invention Same as above, block diagram of electric washing machine Circuit diagram of electric washing machine in Embodiment 2 of the present invention Same as above, block diagram of electric washing machine Circuit diagram of electric washing machine according to Embodiment 3 of the present invention Same as above, block diagram of electric washing machine Circuit diagram of a conventional electric washing machine

Explanation of symbols

31 AC power supply 36, 140 Rectifier circuit 40 Electric motor 45 Inverter circuit 60, 100 Heat generation means 71, 120 Drum 82 Water supply means 90 Bidirectional power conversion circuit 103 Input power detection means 141 Compressor 150 Heat pump

Claims (6)

A brake period that includes a drum for storing clothes, an electric motor for rotationally driving the drum, a water supply means for supplying water into the drum, and a heat generating means for heating the water in the drum to suppress the rotation of the drum And an electric washing machine in which at least a part of the kinetic energy of the drum is supplied to the heat generating means. A drum for storing clothes; an electric motor for rotationally driving the drum; and heat generating means for heating air in the drum, and at least part of the kinetic energy of the drum is applied during a braking period for suppressing rotation of the drum. An electric washing machine supplied to the heating means. A rectifier circuit that inputs an AC power supply and outputs a DC voltage; and an inverter circuit that is connected to the rectifier circuit and drives an electric motor. The inverter circuit regenerates electric power from the electric motor as an input during a braking period. The electric washing machine according to claim 1 or 2, wherein a current is supplied to the heat generating means connected to the input. A bidirectional power conversion circuit that performs bidirectional power conversion provided between an AC power source and an electric motor, and during the braking period, the bidirectional power conversion circuit regenerates electric power from the electric motor as an input, The electric washing machine according to claim 1 or 2, wherein an electric current is supplied to the connected heating means. 5. The electric laundry according to claim 4, further comprising an input power detection unit configured to detect input power from an AC power source, wherein the bidirectional power conversion circuit performs an operation during a brake period within a range in which an output of the input power detection unit does not become negative. Machine. The electric washing machine according to any one of claims 1 to 5, wherein the heat generating means is a heat pump having a compressor.