JPH06170080A - Abnormal vibration detecting method for automatic washing machine - Google Patents

Abstract

PURPOSE:To provide the automatic washing machine executing safely a spin- drying process with high operational efficiency without giving damage to the washing and a machine by adopting a measure for preventing vibration before abnormal vibration is generated in a state of a high speed rotation. CONSTITUTION:The washing machine is provided with an induction motor driving to rotate a rotary drum, and an inverter circuit for driving the induction motor, and a washing process of rotating forward and backward the rotary drum, a baalance process of rotating it at a low speed and a spin-drying process of rotating it at a high speed are executed successively and continuously. In such a state, as soon as the balance process is started, a current effective value I0 is detected from the output of the inverter circuit 2, and from the maximum current value IH and the minimum current value IL of the current effective value I0, a detection difference current value DELTAI1 is calculated, compared with an excessive vibration current set value DELTAI0 set in advance, and in the case of exceeding the set value DELTAI0, the value DELTAI1 is set as an excessive vibration detection current value DELTAI2 and outputted an excessive vibration warning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting abnormal vibration in a dehydration process of an automatic washing machine for home or business use.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting an abnormal vibration in a dehydration process of an automatic washing machine, a rotating drum, which holds a laundry and a washing liquid and rotates, is rotatably supported by an inner frame,
The inner frame is supported on the outer frame of the automatic washing machine by a buffer mechanism such as a spring, and the mechanical vibration of the inner frame is detected by a vibration detector provided on the outer frame (for example, Japanese Patent Laid-Open No. 61-9).
8286, JP-A-58-9994). The dehydration process is
First, a rotating drum is rotated at a low speed by a motor to perform a balancing process of uniformly attaching laundry to the inner wall of the rotating drum by centrifugal force, and then a rotating drum is rotated at a high speed to perform a dehydrating process.

[0003]

However, in the above configuration, when the balancing process is performed at a low speed rotation, the amplitude of mechanical vibration is small even if the rotating drum is unbalanced depending on how the laundry is stuck. , Abnormal vibration cannot be detected. When the rotating drum rotates at a high speed, the vibration becomes large and the abnormal vibration can be detected, and it cannot be detected whether the abnormal vibration occurs before the high speed rotation. Therefore, there is a drawback in that the laundry is stopped after the abnormal vibration is generated, which may damage the laundry or the washing machine, and a lot of useless time is required before the rotating drum is stopped. SUMMARY OF THE INVENTION It is an object of the present invention to provide an abnormal vibration detection method for an automatic washing machine, which detects abnormal vibration due to unbalance before rotating the rotating drum at a high speed and performs a dehydration process that is safe and has high operating efficiency. It is a thing.

[0004]

SUMMARY OF THE INVENTION The present invention comprises an induction motor for rotationally driving a rotating drum, and an inverter circuit for driving the induction motor, and the washing step of rotating the rotating drum in the forward and reverse directions and rotating at a low speed. In a method for detecting abnormal vibration of an automatic washing machine that successively performs a balance step and a dehydration step of rotating at high speed, at the same time as the start of the balance step, the effective current value is detected from the output of the inverter circuit, and the effective current value The detected difference current value is calculated from the maximum current value and the minimum current value, compared with a preset over-vibration current set value, and when it exceeds it, it is output as an over-vibration warning as an over-vibration detection current value. Further, the maximum current value exceeding the preset maximum current setting value is detected from the maximum current value and is output as an over-vibration warning.

[0005]

[Operation] After the washing process, at the same time when the balancing process is started, the maximum current value and the minimum current value are obtained from the effective current value of the induction motor to calculate the detection difference current value, and the preset over-vibration current setting value is set. In comparison, if it exceeds the threshold value, an over-vibration detection current value is output as an over-vibration warning so that measures against the over-vibration can be taken before the dehydration process. Also, when the maximum current value that exceeds the preset maximum current setting value is detected from the maximum current value, it is output as an over-vibration warning,
Over-vibration in the dehydration process is also detected.

[0006]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a vibration detecting circuit showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a relationship between a control circuit of an induction motor for driving a rotating drum and a vibration detecting circuit. The induction motor 1 is a three-phase power source. Inverter circuit 2 connected to R, S, T
Driven through. The inverter circuit 2 is a sequence controller (not shown) that drives the induction motor 1 in the sequence shown in FIG. 3 to rotate the induction motor that performs normal rotation / reverse rotation of the washing process, low-speed rotation of the balancing process, and high-speed rotation of the dehydration process. The frequency command for determining the number is received and output to the induction motor 1 via the output lines U, V and W. The current transformer CT for the instrument is connected to each of the output lines U and W.
₁ and CT ₂ are provided, and the output thereof is passed through the two-phase / three-phase converter 3 and the effective value converter 4 to determine the current effective value I ₀ as the vibration detection circuit
I am trying to type in. Further, a vibration detection command signal is input to the vibration detection circuit 5 from the sequence controller at the same time when the balancing process is started. In the vibration detection circuit 5, the input effective current value I ₀ is input to the maximum current value detecting / holding device 52 and the minimum current value detecting / holding device 53 via the first-order delay circuit 51 to obtain the maximum current value I _H. The minimum current value I _L is held. On the other hand, the vibration detection command signal T ₀
Is set as the internal valid signal T ₁ after the current value in the balancing process is stabilized through the on-delay timer 54, the rising edge of the internal valid signal T ₁ is detected by the rising edge detector 55, and the clear signal T ₂ is generated to clear the signal. The signal T ₂ is detected by the maximum current value detecting / holding device 52 and the minimum current value detecting / holding device 53.
To erase the data before the rise of the internal valid signal T ₁ . After the rise of the internal valid signal T ₁ , a balancing process is performed as shown in FIG. 3, but the maximum current value I _H
And the current minimum value I _L are input to the over-vibration detection current calculator 56, and the current maximum value I _H is input to the maximum current comparator 57. To the maximum current comparator 57, the maximum current setting value I _H0 preset in the maximum current setting device 58 is input, and the maximum current value I
The comparison value between _H and the maximum current setting value I _H0 is input to the AND circuit 59. The logical product circuit 59 logically ANDs the comparison value of the maximum current comparator 57 and the internal valid signal T ₁ and inputs the logical product to the logical sum circuit 60. The over-vibration detection current calculator 56 determines the maximum current value I _H.
And by calculating the detected difference current [Delta] it ₁ is the difference between the current minimum value I _L is input to the over-vibration current comparator 61. The over-oscillation current comparator 61 compares the over-oscillation current setting value ΔI ₀ preset in the over-oscillation current setting device 62 with the detection difference current value ΔI ₁ , and inputs the comparison value to the AND circuit 63. AND circuit 63
Is multiplied by the comparison value of the over-oscillation current comparator 61 and the internal valid signal T ₁ and input to the logical sum circuit 60. OR circuit 60
Shows that when the internal valid signal T ₁ is ON, the over-vibration detection current value ΔI ₂ which is the detection difference current value ΔI ₁ exceeding the over-vibration current setting value ΔI ₀ or the maximum current setting value I _H0 is exceeded. The maximum current value I _H is output as an over-vibration warning. As described above, in the balancing step, the over-vibration state is warned by detecting the over-vibration detection current ΔI ₂ which exceeds the over-vibration current setting value ΔI ₀ generated by the unbalance of the laundry from the effective current value of the induction motor. It is possible to take a measure such as stopping the induction motor before starting the dehydration process in which the rotation speed is high. Also be similarly detected when it and detects the current maximum value I _H exceeding the maximum current setting value I _H0 since the beginning of the dehydration step in the over-oscillation state.

[0007]

As described above, according to the present invention, since the unbalance of the rotating drum is detected in the balancing step of rotating the rotating drum at a low speed before the dehydration step of rotating the rotating drum at a high speed, the high speed rotation of the rotating drum is detected. It is possible to take measures to prevent vibration before abnormal vibration occurs in the state, and it is possible to provide an automatic washing machine that does not damage the laundry or the machine and performs a safe and highly efficient dehydration process. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing a vibration detection circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a sequence of an example of the present invention.

[Explanation of symbols]

 1 Induction motor 2 Inverter circuit 5 Vibration detection circuit 51 Primary delay circuit 52 Current maximum value detection / retainer 53 Current minimum value detection / retention 54 On-delay timer 55 Rise detector 56 Over-vibration detection current calculator 57 Maximum current comparison Device 58 Maximum current setting device 59, 63 Logical product circuit 60 Logical sum circuit 61 Over oscillation current comparator 62 Over oscillation current setting device

Claims (2)

[Claims] 1. An induction motor for rotating a rotating drum, and an inverter circuit for driving the induction motor, comprising: a washing step of rotating the rotating drum forward and backward, a balance step of rotating the rotating drum at a low speed, and a dehydration step of rotating the rotating drum at a high speed. In the abnormal vibration detection method for an automatic washing machine that successively performs and, the effective current value is detected from the output of the inverter circuit at the same time as the start of the balancing step, and the effective current value has the maximum current value and the minimum current value. Abnormal vibration detection of an automatic washing machine characterized by calculating a detection difference current value, comparing it with a preset over-vibration current set value, and when exceeding it, outputting as an over-vibration detection current value as an over-vibration warning Method. 2. The abnormal vibration detection method for an automatic washing machine according to claim 1, wherein a maximum current value exceeding a preset maximum current setting value is detected from the maximum current value and is output as an over-vibration warning.