JP3691282B2 - Washing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a washing machine, and more particularly to a load amount detection device that detects the amount of laundry in a washing machine.
[0002]
[Prior art]
The fully automatic washing machine automatically detects the weight of the laundry put into the washing dehydration tank (that is, the load amount) before starting a series of washing steps, and the washing water level and washing time suitable for the amount. By setting the, it is possible to demonstrate sufficient washing performance while saving water and time.
[0003]
Various methods are conventionally known as methods for detecting the load of a washing machine. For example, in the load amount detection method disclosed in Japanese Patent Laid-Open No. 63-206283, a motor that rotationally drives the pulsator is turned on after turning on for a predetermined time, and a pulse signal synchronized with the rotation of the motor is counted immediately after the turning off, The load amount is determined based on the count value of the pulse signal until the motor stops rotating due to inertia. FIG. 9 is a graph showing an example of the relationship between the pulse count value and the load amount in such a load amount detection method. Since the pulsator stops earlier as the load amount is larger, it can be determined that the load amount is larger as the count value is smaller.
[0004]
[Problems to be solved by the invention]
As is clear from FIG. 9, in the load amount detection method, the amount of change in the count value with respect to the load amount decreases as the load increases (the slope of the tangent line of the curve in FIG. 9 becomes gentle). The detection accuracy is relatively deteriorated compared to when the load is small. In order to improve the detection accuracy when the load is heavy, increase the rotation speed of the pulsator immediately before turning off the motor, or repeat the motor on / off many times and integrate the count value at the inertia rotation Thus, it is necessary to increase the pulse count value. However, the higher the rotational speed of the pulsator, the greater the noise generated by the friction between the laundry and the inner wall of the pulsator and laundry dewatering tub. On the other hand, if the number of times the motor is turned on / off is increased, time is required for the load amount detection process, which increases the time required for washing and causes discomfort to the user.
[0005]
The present invention has been made to solve the above-described problems, and the object of the present invention is to detect the load with high accuracy even when the load is large, and to generate excessive noise when the load is small. An object of the present invention is to provide a washing machine equipped with a load amount detection device that does not occur and requires only a short time for load amount detection processing.
[0006]
[Means for Solving the Problems]
The present invention, which has been made to solve the above-mentioned problems, rotates a pulsator or a laundry dewatering tub for a short time, and detects the amount of laundry accommodated in the laundry dewatering tub according to the inertial rotation thereafter. In a washing machine equipped with a detection means,
The load amount detecting means includes
a) a motor for rotating the pulsator or the washing and dewatering tank;
b) signal generating means for generating a pulse signal synchronized with the rotation of the motor;
c) counting means for counting the number of the pulse signals according to the duration of inertial rotation when the motor is turned on and turned off after the rotational speed has increased to a predetermined rotational speed;
d) Using the predetermined rotational speed as a first rotational speed, a count value is obtained by the counting means during inertial rotation when the motor is turned up to the first rotational speed and then turned off, and this count value is a predetermined value. In the case of the following, the predetermined rotation speed is set to a second rotation speed larger than the first rotation speed, and the counting means again performs inertial rotation when the motor is raised to the second rotation speed and then turned off. A control means for obtaining a count value;
e) When the count value for the first rotation speed is greater than the predetermined value, the load amount is determined based on the count value for the first rotation speed, and the count value for the first rotation speed is the predetermined value. A load amount determination means for determining a load amount based on a count value with respect to the second rotation speed,
It is characterized by including .
[0008]
Further, in the washing machine according to the present invention, the control means is configured to repeatedly turn the motor on and off a plurality of times in order to obtain a count value at the time of inertia rotation for a certain drive rotation speed. Is preferred.
[0009]
In this case, it is more preferable that the control means reverses the rotation direction at least once when the motor is turned on.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The greater the amount of laundry contained in the laundry dewatering tub, the less likely the pulsator will rotate and the shorter the time it will continue to rotate due to inertial rotation. Therefore, in the washing machine according to the present invention, the control means first turns on the motor, increases its rotational speed to the first rotational speed, and then turns off the motor. In the subsequent inertial rotation, when the count value acquired by the counting means is equal to or less than the predetermined value, it is determined that the load amount is too large to determine the load amount using the count value. In that case, the motor is turned on after the motor is turned on so that the rotational speed of the motor increases to the second rotational speed, which is a higher rotational speed, and a count value corresponding to the inertial rotation thereafter is acquired. Since the inertial rotation continues longer as the rotational speed at the time when the pulsator shifts to inertial rotation, the count value acquired for the second rotational speed is larger than the count value acquired for the first rotational speed. That's it. Based on the count value thus obtained, the load amount determination means determines that the load amount is larger as the count value is smaller. As described above, the count value acquired with respect to the second rotation speed is relatively large, so that it is possible to make a precise determination even for a large load amount.
[0011]
Therefore, according to the washing machine according to the present invention, even when the load amount is large, the load amount can be detected with high accuracy. Further, when the load amount is small, the rotational speed of the pulsator is relatively low, so that noise is suppressed and the fabric is less damaged. Further, when the load amount is small, it is not necessary to increase the drive rotation speed and perform the load amount determination again, so that the time required for load amount detection does not increase.
[0012]
Note that if the motor is repeatedly turned on and off a plurality of times in order to obtain a count value at the time of inertial rotation for a certain drive rotational speed, the influence of the laundry arrangement condition, etc. is mitigated. The quantity can be detected more accurately.
[0013]
Moreover, depending on the arrangement of the laundry in the laundry dewatering tub, the load applied to the pulsator may differ depending on the rotation direction of the left and right, but if the rotation direction is reversed at least once, The influence can be reduced and the load amount can be detected even more accurately.
[0014]
【Example】
Hereinafter, an embodiment of a washing machine according to the present invention will be described with reference to the drawings.
FIG. 1 is a side sectional view showing the structure of the washing machine of this embodiment. An outer tub 2 is supported by four suspension rods 3 inside a machine frame 1 of the washing machine, and a washing / dehydrating tub 4 having a number of dewatering holes in its peripheral wall is provided inside the outer tub 2 with a main shaft 5. It is pivotally supported at the center. A pulsator 6 for agitating the laundry is disposed at the bottom of the laundry dewatering tub 4. The rotational power of the motor 7 attached to the lower surface of the outer tub 2 is the motor pulley 8, the V belt 9, the main pulley 10, and the power. This is transmitted to the washing and dewatering tub 4 and the pulsator 6 through the switching mechanism 11.
[0015]
A water supply pipe 13 provided with a water supply valve 12 is provided in the middle of the upper part of the machine casing 1 as a water supply mechanism, and the water supplied from the outside through the water supply pipe 13 includes a detergent container and a softening agent container. Water is injected from the water injection port 14 into the washing and dewatering tank 4. On the other hand, a drain port 15 is opened at the bottom of the outer tub 2, and is connected to a drainage hose 18 that can stand up through a drain valve 16 and a drain channel 17. A torque motor 19 is attached to the drain valve 16. When the torque motor 19 is driven, the drain valve 16 is opened by pulling a wire, and a clutch (not shown) in the power switching mechanism 11 is further driven. The laundry dewatering tub 4 and the pulsator 6 are connected to each other and the brake (not shown) is released. As a result, only the pulsator 6 rotates when the drain valve 16 is closed, and the laundry dewatering tub 4 and the pulsator 6 rotate together when the drain valve 16 is opened.
[0016]
In this washing machine, when only the pulsator 6 is driven to rotate, the reduction ratio of the rotational speed between the motor 7 and the pulsator 6 is approximately 10: 1. For example, when the motor 7 rotates at 1200 rpm, the pulsator 6 Rotate at 120 rpm.
[0017]
FIG. 2 is an electrical configuration diagram of the main part of the washing machine. The control unit 20 includes a memory 21, a timer 22, a pulse counter 23, and the like centered on a well-known microcomputer. Each operation process related to washing is executed by executing an operation program stored in the memory 21 in advance. To proceed. A motor drive unit 24, a valve drive unit 25, an operation unit 26, and a display unit 27 are connected to the control unit 20, and the operation of the motor 7 is controlled via the motor drive unit 24 including an inverter circuit and the like. The opening and closing of the water supply valve 12 and the drainage valve 16 are controlled through a valve drive unit 25 including The motor 7 is provided with a pulse generator 28 that generates a pulse signal as the motor 7 rotates. In this embodiment, the pulse generator 28 generates 20 pulse signals at almost equal angular intervals during the period in which the motor 7 rotates once.
[0018]
The washing machine of this embodiment is characterized by a load amount detection process that is usually executed at the very beginning of the washing process. 3-6 is a flowchart which shows the load amount detection process in this washing machine. The control operation during the load amount detection process will be described with reference to FIGS.
[0019]
When the user puts the laundry into the laundry dewatering tub 4 and gives an instruction to start washing through the operation unit 26, the control unit 20 starts the load amount detection process. First, the control unit 20 initializes the pulse counter 23 (step S1), turns on the motor 7 via the motor drive unit 24, and controls the rotation speed to increase to 600 rpm (step S2). At this time, the drain valve 16 is closed, and the power switching mechanism 11 allows only the pulsator 6 to rotate while the washing and dewatering tub 4 is stopped. If the rotation speed of the motor 7 reaches 600 rpm (“Y” in step S3), it is turned off (step S4), and the pulse counter 23 starts counting the pulse signal almost simultaneously (step S5).
[0020]
Immediately before the motor 7 is turned off, the pulsator 6 rotates at about 60 rpm. When the motor 7 is turned off, the pulsator 6 continues to rotate while its speed decreases due to the inertia of the rotational driving force immediately before the motor is turned off. As the amount of laundry increases, the rotational load applied to the pulsator 6 increases, so the decrease in the speed of inertial rotation stops remarkably quickly.
[0021]
The control unit 20 measures the elapsed time after the motor is turned off by the timer 22, and temporarily stops counting by the pulse counter 23 when a predetermined time T (for example, about 1.5 seconds) has elapsed ("Y" in step S6). (Step S7). The predetermined time T is set longer than the time when the pulsator 6 is surely stopped even when the laundry is not stored in the laundry dewatering tub 4. Therefore, when T seconds have elapsed in step S6, the total number of pulse signals obtained during the period in which the pulsator 6 is rotating due to inertia is held in the pulse counter 23 as a count value.
[0022]
Next, the control unit 20 controls the motor drive unit 24 so that the rotation speed thereof increases to 600 rpm in the direction opposite to the previous rotation direction (step S8). When the rotational speed reaches 600 rpm (“Y” in step S9), the motor 7 is turned off (step S10), and at the same time, counting of the pulse signal by the pulse counter 23 is restarted (step S11). By the processing in step S12 similar to step S6, the control unit 20 measures the elapsed time after the motor is turned off by the timer 22, and when the predetermined time T seconds has elapsed ("Y" in step S12), the control unit 20 The counting is finished (step S13). Thereby, the pulse counter 23 holds the count value n1 of the pulse signal during the two inertial rotation periods.
[0023]
The control unit 20 executes the first load amount determination based on the count value n1 (step S20). FIG. 7 is a graph showing the relationship between the load amount and the pulse count value at this time. Such a relationship is experimentally obtained in advance, and based on this, the following threshold value for determining the load amount is determined.
[0024]
That is, the control unit 20 determines whether or not the count value n1 is greater than 40 (step S21), and determines whether or not the count value n1 is greater than 50 when it is greater. (Step S22) If it is larger, it is determined whether or not the count value n1 is larger than 70 (Step S23). If the count value n1 is 50 or less in step S22, it is determined that the load amount is 2 to 3 kg (step S24). If the count value n1 is 70 or less in step S23, it is determined that the load amount is 1 to 2 kg (step S25). If the count value n1 is greater than 70, the load amount is It is judged that it is 0-1 kg (step S26). If the load amount is 3 kg or less, the load amount detection process ends at this point, and the time required for the process can be shortened. In addition, since the rotational speed in steps S3 and S9 is relatively low, noise caused by friction between the laundry and the inner wall of the pulsator 6 and the washing / dehydrating tub 4 is small, and there is almost no risk of cloth damage.
[0025]
If the count value n1 is 40 or less in step S21, it can be determined that the load amount is 3 kg or more as is apparent from FIG. 7, but with this count value n1, more accurate determination is possible. Can not. Therefore, the control unit 20 sets the rotation speed of the motor 7 to 1500 rpm, which is 2.5 times the previous speed, and calculates the pulse signal due to the two inertial rotations by the process of steps S31 to S43 similar to steps S1 to S13. Find the numerical value n2. At this time, since the rotational speed of the pulsator 6 immediately before the motor 7 is turned off is about 150 rpm, inertial rotation continues for the same load amount longer than in the previous case. Therefore, the count value n2 is larger than the count value n1.
[0026]
The control unit 20 executes the second load amount determination based on the count value n2 (step S50). FIG. 8 is a graph showing the relationship between the load amount and the pulse count value at this time. As described above, the count value n2 becomes large, so that the identification becomes easy even in the range of the load amount of 3 kg or more.
[0027]
That is, the control unit 20 determines whether or not the count value n2 is smaller than 100 (step S51). When the count value n2 is smaller, the control unit 20 determines whether or not the count value n2 is smaller than 80. (Step S52) If it is smaller, it is determined whether the count value n2 is smaller than 70 (Step S53). If it is smaller, the count value n2 is smaller than 60. It is determined whether or not (step S54). If the count value n2 is 100 or more in step S51, it is determined that the load amount is 3 to 4 kg (step S55). If the count value n2 is 80 or more in step S52, the load is determined. It is determined that the amount is 4 to 5 kg (step S56). If the count value n2 is 70 or more in step S53, it is determined that the load amount is 5 to 6 kg (step S57), and step S54 is performed. When the count value n2 is 60 or more, it is determined that the load amount is 6 to 7 kg (step S58). When the count value n2 is smaller than 60, the load amount is 7 kg or more. Judgment is made (step S59).
[0028]
In this way, a load amount of 3 kg or more is also accurately detected by the second load amount determination. Since an appropriate water level is determined in advance for each load amount determined as described above, after the load amount detection process, the water supply valve 12 is opened to supply water up to the set water level. Operation starts.
[0029]
The load amount detection process as described above can be applied not only immediately after the start of the washing process, that is, when the laundry is dry, but also when the laundry contains water, such as after intermediate dehydration. is there. Of course, in that case, the load is the weight of the laundry containing water.
[0030]
In the washing machine of the above embodiment, only the pulsator 6 is rotationally driven during the load amount detection process. However, the washing machine according to the present invention includes the washing / dehydrating tub 4 and the pulsator 6 during the load amount detection process. It can also be applied to those that rotate and drive together.
[0031]
In that case, when the laundry dewatering tub 4 is driven to rotate for a short time by the motor 7 after the laundry is put into the laundry dewatering tub 4, the duration of the inertial rotation thereafter is the load amount contrary to the above case. The larger the value, the longer. This is because a larger inertial force acts as the load amount increases. Therefore, the smaller the load amount, the smaller the pulse count value, and the load amount detection accuracy decreases. On the other hand, there is a problem that the vibration of the washing / dehydrating tub 4 increases as the rotation speed is increased. In order to avoid this problem, it is desirable to detect the load amount with a rotation speed as low as possible.
[0032]
Therefore, if, for example, according to the flowchart shown in FIG. 3, the pulse count value n1 at the time of inertia rotation when the laundry dewatering tub 4 is rotationally driven at a relatively low rotational speed is obtained, the pulse count value n1 is obtained. A large load amount is determined based on the above. If the counted value n1 is smaller than the predetermined value, the washing / dehydrating tub 4 is driven to rotate at a relatively high rotational speed in accordance with the flowchart shown in FIG. The count value n2 is acquired. Then, a small load amount is determined based on the pulse count value n2. As a result, the detection accuracy at a low load is improved and the rotational speed is not increased unnecessarily, so that the possibility of large vibrations is reduced.
[0033]
In the above embodiment, the rotational speed of the motor 7 during the load amount detection process is changed in two stages, but it may be changed in more stages. Moreover, the said Example is an example and it is clear that it can change and correct suitably in the range of the meaning of this invention.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a configuration of an embodiment of a washing machine according to the present invention.
FIG. 2 is an electric system configuration diagram of a main part of the washing machine according to the present embodiment.
FIG. 3 is a flowchart showing load amount detection processing in the washing machine according to the embodiment.
FIG. 4 is a flowchart showing load amount detection processing in the washing machine of the present embodiment.
FIG. 5 is a flowchart showing load amount detection processing in the washing machine of the present embodiment.
FIG. 6 is a flowchart showing load amount detection processing in the washing machine according to the embodiment.
FIG. 7 is a graph showing a relationship between a load amount and a pulse count value at the first load amount determination.
FIG. 8 is a graph showing a relationship between a load amount and a pulse count value at the time of second load amount determination;
FIG. 9 is a graph showing a relationship between a pulse count value and a load amount in a load amount detection process in a conventional washing machine.
[Explanation of symbols]
2 ... Outer tub 4 ... Washing and dewatering tub 6 ... Pulsator 7 ... Motor 20 ... Control unit 21 ... Memory 22 ... Timer 23 ... Pulse counter 24 ... Motor drive unit 28 ... Pulse generator

Claims (3)

In a washing machine equipped with a load amount detection means for detecting the amount of laundry stored in the laundry dewatering tank according to the inertial rotation after the pulsator or the laundry dewatering tank is rotated for a short time,
The load amount detecting means includes
a) a motor for rotating the pulsator or the washing and dewatering tank
b) signal generating means for generating a pulse signal synchronized with the rotation of the motor;
c) counting means for counting the number of pulse signals according to the duration of inertial rotation when the motor is turned on and turned off after the rotational speed has increased to a predetermined rotational speed;
d) Using the predetermined rotational speed as a first rotational speed, a count value is obtained by the counting means in inertial rotation when the motor is turned up to the first rotational speed and then turned off. In the case of the following, the predetermined rotation speed is set to a second rotation speed larger than the first rotation speed, and the counter is again used in inertial rotation when the motor is raised to the second rotation speed and then turned off. A control means for obtaining a count value;
e) When the count value for the first rotation speed is greater than the predetermined value, the load amount is determined based on the count value for the first rotation speed, and the count value for the first rotation speed is the predetermined value. A load amount determination means for determining a load amount based on a count value with respect to the second rotation speed when the value is equal to or less than a value;
A washing machine comprising: 2. The washing machine according to claim 1, wherein the control unit repeatedly turns the motor on and off a plurality of times in order to obtain a count value during inertial rotation with respect to a certain drive rotation speed. . The washing machine according to claim 2, wherein the control means reverses the rotation direction at least once when the motor is turned on .

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