Washing machine

Abstract

To provide a washing machine with low vibration which can suppress abnormal vibration properly with respect to an ambient temperature of the washing machine.SOLUTION: A washing machine 100 includes: a housing 1; an outer tub 11 supported in the housing 1, and capable of storing a liquid inside; vibration detection means for detecting the vibration of the outer tub 11; temperature detection means 25 for detecting an ambient temperature; a motor 22 fixed to the outer tub 11, and for generating a driving force for agitating clothing; and a control part 7 for controlling the motor 22. The control part 7 is constituted so that rotation control of the motor is performed according to a comparison result of an output of the vibration detection means and a vibration threshold value expressing permissible vibration. The vibration threshold value has a continuous value with respect to a detection temperature of the temperature detection means 25.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a washing machine. [Background technology]

[0002] A washing machine is composed of an outer tub that holds water, a rotatable washing tub contained within the outer tub, and a housing that contains the outer tub and the washing tub.When running the spin-dry cycle, the washing tub rotates at high speed and the clothes are dehydrated using centrifugal force, so if the clothes are unevenly distributed in the washing tub, vibrations will occur in the outer tub and housing.

[0003] The vibration during the spin cycle is damped by anti-vibration structures such as anti-vibration rubber and dampers at the connection between the outer tub and the housing, and anti-vibration rubber (rubber feet) at the bottom of the housing. In terms of control, the rotation speed of the washing tub is controlled so that the detection results of the acceleration sensor installed in the outer tub and the vibration detection means that detects vibrations based on the driving current and rotation speed of the washing tub do not exceed a preset vibration threshold value.

[0004] However, since the vibration characteristics of anti-vibration rubber and dampers change depending on the ambient temperature, it is desirable to control the rotation of the washing tub while taking the ambient temperature into consideration in order to appropriately prevent abnormal vibration.

[0005] A conventional technique for controlling the rotation speed of the washing tub during a spin cycle, taking into account the ambient temperature, is disclosed in Patent Document 1. In Patent Document 1, a temperature detection means for detecting the ambient temperature and a vibration detection means for detecting the vibration of the outer tub are provided, and the rotation of the washing tub is controlled based on the results of the temperature detection means and the vibration detection means. It is described that a vibration threshold is set for each of two consecutive temperature zones, and that the vibration threshold for the lower temperature zone is set smaller than that for the higher temperature zone. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-168232 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the spin cycle of a washing machine, the rotation speed of the washing tub is increased stepwise to perform centrifugal spin-drying at high speed, which causes the outer tub and the housing to vibrate due to the imbalance of the clothes. If the amount of imbalance of the clothes is large and the outer tub and the housing vibrate excessively, it may cause discomfort to the user or, in the worst case, damage to the washing machine.

[0008] In order to suppress this vibration during the spin-drying operation, measures are generally taken in terms of both the structure of the washing machine and the control of the washing tub.

[0009] In terms of structure, anti-vibration structures such as anti-vibration rubber and dampers are used at the connection between the outer tub and the housing, and anti-vibration rubber (rubber feet) are used at the connection between the housing and the installation floor, but these anti-vibration structures have the problem of being easily affected by temperature.For example, when the ambient temperature is high, the damping force of the dampers decreases, causing the vibration displacement of the outer tub to be greater than at low temperatures even under the same clothing imbalance conditions, and at low temperatures, the hardness of the anti-vibration rubber increases, making it easier for vibrations to be transmitted from the outer tub to the housing and from the housing to the installation floor than at high temperatures.

[0010] In terms of control, the rotation of the washing tub is controlled so that the detection results of the vibration detection means, which detects vibrations in the outer tub, do not exceed a predetermined vibration threshold. However, since this is affected by changes in structural characteristics due to the ambient temperature, depending on the ambient temperature, a mismatch can occur between the predetermined vibration threshold and the actual vibration generated by the washing machine, posing the problem that abnormal vibrations cannot be properly prevented.

[0011] The technology described in Patent Document 1 has a temperature detection means for detecting the surrounding temperature, and vibration thresholds are set for two consecutive temperature zones, and it is described that by setting a smaller vibration threshold in the lower temperature zone to prevent excessive vibration that occurs at low temperatures, it is possible to protect the insulating coating wired to a motor, etc. Since it is necessary to set the vibration threshold for each temperature zone, the vibration thresholds set for the temperatures are discrete values, and appropriate vibration thresholds are not set at temperatures near the transition between temperature zones, so there is a possibility that abnormal vibrations cannot be properly prevented.

[0012] Furthermore, in Patent Document 1, the vibration threshold is set higher in the high temperature range than in the low temperature range. On the other hand, since the hardness of the rubber parts decreases at high temperatures, it is possible that the vibration mode changes at the rotation speed at which the outer tub resonates, and it is not necessarily appropriate to set the vibration threshold higher in the high temperature range. For example, if an acceleration sensor or a displacement sensor that detects the vibration acceleration or displacement of the outer tub is used as the vibration detection means, even under the same clothes imbalance conditions, it is possible that the result of the vibration detection means will be smaller at high temperatures because the value detected will be closer to the node of the outer tub vibration depending on the change in the vibration mode.

[0013] Also, in the embodiment of Patent Document 1, it is stated that a vibration threshold is set for each combination of the temperature zone and the weight rank of the clothing weight. It becomes necessary to set the vibration threshold in advance for each combination of the temperature zone and the weight rank. Furthermore, in addition to the contents described in Patent Document 1, a washing machine can generally be set to start up a plurality of spin-drying operations. For example, when the start-up settings have a standard setting, a smooth setting, and a low vibration setting, the magnitude relationship of the vibration threshold is set as low vibration setting < standard setting < smooth setting, so in addition to the above temperature zone and the weight rank of the clothing weight, it is necessary to set a vibration threshold for each combination of the start-up settings.

[0014] For example, in the case of n temperature zones, m weight ranks, and one startup setting, it is necessary to set n x m x l vibration thresholds. Therefore, when the temperature zones, weight ranks, and startup settings are finely set to appropriately suppress abnormal vibrations, there is a risk that the memory of the microcomputer that controls the washing machine will be strained.

[0015] An object of the present invention is to provide a washing machine that can appropriately suppress abnormal vibrations regardless of the ambient temperature of the washing machine. [Means for solving the problem]

[0016] The washing machine of the present invention for achieving the above object includes a housing, an outer tub supported within the housing and capable of storing liquid therein, a vibration detection means for detecting vibrations of the outer tub, a temperature detection means for detecting the ambient temperature, a motor fixed to the outer tub and generating a driving force for agitating the clothes, and a control unit for controlling the motor, the control unit being configured to control the rotation of the motor according to a comparison result between the output of the vibration detection means and a vibration threshold value representing an allowable vibration, the vibration threshold value having a continuous value with respect to the temperature detected by the temperature detection means. Other aspects of the present invention will be described in the embodiments described later. Effect of the Invention

[0017] According to the present invention, abnormal vibrations can be appropriately suppressed. [Brief description of the drawings]

[0018] [Figure 1] 1 is a perspective view of a drum-type washing machine according to a first embodiment. [Diagram 2] 1 is a cross-sectional view of an inner structure of a drum-type washing machine according to a first embodiment, as viewed from the right side. [Diagram 3] 4 is a time chart of the drum rotation speed during a spin-drying process of the drum type washing machine according to the first embodiment. [Figure 4] 5 is a flowchart showing an update of a vibration threshold value according to the first embodiment. [Diagram 5]4 is a schematic diagram showing the relationship between a vibration threshold and an ambient temperature according to the first embodiment. FIG. [Figure 6] FIG. 11 is a schematic diagram showing the relationship between a vibration threshold and an ambient temperature according to the second embodiment. [Figure 7] 13A and 13B are schematic diagrams showing differences in vibration modes of the outer tub due to temperature changes according to the second embodiment. [Figure 8] FIG. 13 is a schematic diagram showing a relationship between a threshold coefficient and an ambient temperature according to the third embodiment. [Figure 9] 13 is a specific example of a vibration threshold table for each dehydration start setting, clothing volume weight rank, and temperature range according to a conventional method. [Figure 10] 13 is a specific example of a vibration threshold table for each dehydration start setting, clothing volume weight rank, and temperature range according to the third embodiment. [Figure 11] FIG. 13 is a schematic diagram showing a relationship between a threshold coefficient and an ambient temperature according to the fourth embodiment. [Figure 12] 13 is a time chart of the drum rotation speed during a spin-drying process of the drum type washing machine according to the fifth embodiment. [Figure 13] 13 is a flowchart showing a process for updating a vibration threshold value according to the number of spin-drying processes according to a fifth embodiment. [Figure 14] FIG. 13 is a schematic diagram showing an update amount of a vibration threshold value according to the number of spin-drying processes in the fifth embodiment. [Figure 15] 23 is a flowchart showing an update of a vibration threshold value according to clothing imbalance according to the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of a drum type washing machine for carrying out the present invention will be described with reference to the drawings. Note that the embodiment of the present invention is not limited to a drum type washing machine, but can also be applied to other types of washing machines that dehydrate clothes by centrifugal force, such as a vertical washing machine.

[0020] First Embodiment Fig. 1 is a perspective view of a drum type washing machine 100 according to the first embodiment. Fig. 2 is a cross-sectional view of the inner structure of the drum type washing machine according to the first embodiment, seen from the right side. The configuration and operation of the drum type washing machine 100 will be described with reference to Figs. 1 and 2.

[0021] The housing 1 constituting the outer shell of the drum-type washing machine 100 shown in Fig. 1 is attached on top of the base 1a, and is composed of left and right side panels 1b (only the right side panel is shown in Fig. 1), a front cover 1c, a rear cover 1d (see Fig. 2), a top cover 1e, and a lower front cover 1f. The top cover 1e is provided with a water supply hose connection port 30 for supplying water to the drum-type washing machine 100 from a water faucet. The housing 1, including the base 1a, forms a box-shaped outer frame, and has sufficient strength as an outer frame. In addition, the base 1a and the four lower corners of the housing 1 are provided with rubber feet 1g, which serve to dampen vibrations of the housing 1.

[0022] The door 2 is for closing an opening (not shown) for putting in and taking out clothes, which is provided at approximately the center of the front cover 1c, and is supported by a hinge provided on the front cover 1c so that it can be opened and closed. The door 2 opens when a locking mechanism (not shown) is released by pulling the door opening handle 2a, and closes when the door 2 is pressed against the front cover 1c. The front cover 1c has a circular opening for putting in and taking out clothes, which is approximately concentric with the opening of the outer tub 11 described later.

[0023] The operation / display panel 3 provided on the top of the housing 1 includes a power switch 4, an operation switch 5, and a display 6. The operation / display panel 3 is electrically connected to a control unit 7 (see FIG. 2) provided on an upper reinforcing member 13 (see FIG. 2) provided on the top of the housing 1. A cooling fan (not shown) is attached to the control unit 7. The control unit 7 also includes a memory capable of recording the operation of the washing machine. An internal drain hose 14 for draining water is attached near the base 1a.

[0024] An outer tub 11 for storing water is provided inside the housing 1 of the drum type washing machine 100 shown in Fig. 2. Two sets of suspension means 8 made of coil springs are connected to the upper part of the outer tub 11 in order to maintain the position of the outer tub 11. The lower part of the outer tub 11 is connected by a plurality of vibration dampers 24 attached to the housing 1. The connections of the vibration dampers 24 to the outer tub 11 and the housing 1 are attached in a rotatable state. The number of vibration dampers 24 may be two or more, and the configuration is not limited.

[0025] The outer tub 11 contains a drum 21 for storing clothes. A motor 22 for rotating the drum 21 is provided behind the outer tub 11. The motor 22 has a shaft 22a which serves as a rotation axis that penetrates the outer tub 11 and is coupled to the drum 21. When the motor 22 is driven, the drum 21 is driven to rotate in both forward (counterclockwise when viewed from the front of the drum type washing machine 100) and reverse (clockwise when viewed from the front of the drum type washing machine 100). The rotation axis Az of the drum 21 shown in FIG. 2 is horizontal or inclined so that the rear side faces downward from the front to the rear of the drum type washing machine 100 (in FIG. 2, it is inclined so that the rear side faces downward). The motor 22 is provided with a rotation speed detection device 10 which detects the rotation speed.

[0026] The inner peripheral surface of the drum 21 is provided with a plurality of dewatering holes 21b for draining the wash water in the drum 21 into the outer tub 11, and a plurality of baffles 23 (only one is shown in FIG. 2) spaced apart in the circumferential direction of the drum 21 for lifting up the clothes placed in the drum 21. The baffles 23 extend in the front-rear direction of the drum 21.

[0027] A cylindrical fluid balancer 21c is provided at the front end of the drum 21. The outer tub 11 is an approximately cylindrical shape with an opening at the front and a closed rear, and has a bottom. The opening of the outer tub 11 and the loading port of the housing 1 are connected by a bellows 16 that easily expands and contracts in the front-rear direction. The bellows 16 is a ring-shaped constrained packing, and the drum 21 is water-sealed by closing the door 2. The loading port of the housing 1, the opening of the outer tub 11, and the opening of the drum 21 are connected to each other, and clothes can be put in and taken out of the drum 21 by opening the door 2. The outer tub 11 can be divided into a side including the opening and a side to which the motor 22 is attached.

[0028] A drain port 19 provided at the bottom of the outer tub 11 is connected to the internal drain hose 14. A circulation pump 20 for circulating the wash water is provided in the lint collection box 17, and the water is sprayed into the drum 21 via a circulation path 20a. A drain valve 15a is provided in the external drain hose 15, and water is stored in the outer tub 11 by closing the drain valve 15a and supplying water, and the water in the outer tub 11 is discharged outside the machine by opening the drain valve 15a.

[0029] Furthermore, an outer tub vibration detector 18 is provided below the outer tub 11 to detect the vibration acceleration and displacement of the outer tub 11. When the vibration of the outer tub 11 exceeds a set threshold, the rotation of the drum 21 is temporarily stopped, the clothes imbalance is corrected, and the spin cycle is restarted. By increasing the rotation speed only when the outer tub vibration is below the threshold, the occurrence of excessive vibration is suppressed.

[0030] Further, a temperature detection means 25 for detecting the ambient temperature of the drum type washing machine 100 is provided, and the threshold value is updated according to the temperature detected by the temperature detection means 25. The method of updating the threshold value will be described in detail in the operation of the spin-drying process described later.

[0031] The operation of the drum type washing machine 100 having the above configuration will be described. In the drum type washing machine 100 configured as above, the user first presses the power switch 4 to start the drum type washing machine 100. Then, the user pulls the door opening handle 2a to open the door 2 and puts clothes into the drum 21. Then, the user closes the door 2 and operates the operation switch 5 to start operation. When operation starts, the drum 21 rotates to calculate the clothes volume before water is poured. The clothes volume is calculated based on the rotation speed and current value of the motor 22. At this time, the larger the clothes volume, the more the load on the motor 22 is increased, and the current value becomes larger, so the clothes volume is determined by the current value. Then, the amount of detergent to be poured is displayed on the display 6 based on the clothes volume. At this time, the larger the calculated clothes volume, the more detergent to be poured. The user checks the display 6, pours a predetermined amount of detergent into the detergent container 12, and starts the washing process.

[0032] In the washing process, the water supply valve 32 is opened, and water supplied from the water supply hose connection port 30 is supplied into the outer tub 11 together with the detergent via the internal water supply hose 31 and the detergent container 12. At this time, the larger the calculated volume of clothes, the larger the amount of water supplied in the washing process. At this time, undissolved detergent and water are agitated in the circulation pump 20. This allows the detergent to be efficiently dissolved, and a highly concentrated detergent solution is produced. After this operation is performed for a predetermined time, a washing operation is performed for a predetermined time in which the drum 21 is rotated forward, stopped, reversed, and stopped repeatedly. At this time, the clothes are washed by repeatedly lifting them up and dropping them down by the baffle 23. After the washing process, a spin-drying process is performed.

[0033] Fig. 3 is a time chart of the drum rotation speed during the spin-drying process of the drum type washing machine 100 according to the first embodiment. The spin-drying process will be described with reference to Fig. 3. Fig. 3 shows a time chart of the rotation speed of the drum 21 during the spin-drying process.

[0034] First, by opening drain valve 15a after the washing step is completed, water in outer tub 11 is drained to the outside (outside of the machine) of drum type washing machine 100 via internal drain hose 14. In the dehydration step, the rotation speed of drum 21 is increased to a target rotation speed section (t5-t6) while passing through a low rotation speed region (t1-t2) in which clothes are spread and stuck on the inner circumferential surface of drum 21, a resonance section (t2-t3) of outer tub 11, a resonance section (t3-t4) of housing 1, and a post-resonance section (t4-t5) of housing 1, to centrifugally dehydrate the water contained in the clothes.

[0035] In the low-speed rotation range, the rotation speed of drum 21 is increased to ω0 (e.g., 50 r / min). At this time, clothes soaked with water during the washing process are lifted by baffle 23 as drum 21 rotates, and as the clothes fall, they are spread out on the inner circumferential surface of drum 21. When the rotation speed of drum 21 reaches ω0, drum 21 is operated at ω0 for a time T1 (e.g., 10 seconds) to detect imbalance at ω0.

[0036] Unbalance detection in the low-speed rotation range is determined based on the magnitude of rotational fluctuation. The rotational fluctuation is determined, for example, from the difference between the speed at which clothes are lifted from the bottom of the drum 21 to the top (minimum speed) and the speed at which clothes are lowered from the top of the drum 21 to the bottom (maximum speed) when the drum 21 makes one rotation. The smaller the rotational fluctuation, the better the balance. When it is determined that the rotational fluctuation is equal to or less than a preset threshold value in unbalance detection at ω0, the rotational speed of the drum 21 is increased from ω0 to ω1 (e.g., 80 r / min).

[0037] When the rotation speed of drum 21 reaches ω1, it is operated at ω1 for a time T2 (e.g., 5 seconds) to detect imbalance. Note that ω0 and ω1 are rotation speeds for detecting the degree of adhesion of clothes, where ω0 is the rotation speed at which clothes start to adhere to the inner surface of drum 21, and ω1 is the rotation speed at which clothes completely adhere to the inner surface of drum 21.

[0038] After operating at ω1 for a predetermined time, if the unbalance detection at ω1 determines that the rotational fluctuation is below a preset threshold, the rotational speed of the drum 21 is increased to ω2 (e.g., 400 r / min) to pass through the resonance zone of the outer tub 11.

[0039] When passing through the resonance zone of the outer tub 11, if the vibration displacement of the outer tub 11 detected by the outer tub vibration detection unit 18 is smaller than a predetermined value, the number of revolutions of the drum 21 is increased to ω3 (e.g., 600 r / min) to pass through the resonance zone of the housing 1.

[0040] When passing through the resonance zone of the housing 1, if the vibration displacement of the outer tub 11 is smaller than a predetermined value, the rotation speed of the drum 21 is increased to a target (e.g., 900 r / min). In the target rotation speed zone, the drum 21 is operated for a predetermined time at T3 (e.g., 180 seconds), and then the rotation speed of the drum 21 is decreased to 0 r / min (t6 to t7) to end the dehydration process.

[0041] The aforementioned rotational fluctuation detection means and outer tub vibration detection unit 18 are collectively referred to as vibration detection means, and the rotational fluctuation threshold and outer tub vibration threshold are collectively referred to as vibration threshold x.

[0042] During the dehydration process, if the clothes stuck to the inner peripheral surface of the drum 21 are significantly unbalanced, the detection result of the vibration detection means will be greater than the vibration threshold value. Therefore, the rotation speed of the drum 21 is reduced or the rotation of the drum 21 is stopped, and an operation to correct the unbalance of the clothes (retry) is performed by repeating forward and reverse rotation of the drum 21 to loosen the clothes or by pouring water.

[0043] Furthermore, even if the amount of clothing imbalance is the same, the vibration characteristics fluctuate due to the temperature-dependent characteristics of rubber parts such as the vibration damper 24 and bellows 16 at the bottom of the outer tub 11, and the optimum vibration threshold value that does not cause abnormal vibrations changes.

[0044] For example, under high temperature conditions, the damping characteristics of the vibration damper 24 decrease, and the outer tub 11 vibrates excessively even under the same clothes imbalance conditions. Therefore, if the same threshold value of the outer tub vibration detection unit 18 is set regardless of temperature, the machine may enter a retry operation even with a small amount of clothes imbalance, which may result in an increase in the time required for the spin cycle.

[0045] On the other hand, under low temperature conditions, the damping characteristics of the vibration damper 24 improve, so that the vibration of the outer tub 11 that occurs when the outer tub 11 resonates becomes smaller even with the same clothes imbalance. Therefore, if the same threshold value of the outer tub vibration detection unit 18 is set regardless of temperature, the rotation speed of the drum 21 will increase while allowing for greater clothes imbalance conditions in the outer tub's resonance range, which may result in excessive vibration in the high rotation range.

[0046] In particular, in the region after the outer tank 11 has passed through the resonance section, the hardness of the rubber feet 1g increases, and the vibration transmitted from the housing 1 to the installation floor also increases, which may cause excessive vibration to be transmitted to the installation floor, resulting in discomfort. Therefore, in order to deal with temperature dependency, the vibration threshold value is configured to be updated based on the temperature detected by the temperature detection means 25.

[0047] FIG. 4 is a flowchart of updating the vibration threshold value x according to the first embodiment. FIG. 4 shows a flowchart of the spin-drying process including the procedure for updating the vibration threshold value x. This flowchart is executed by the control unit 7 (see FIG. 2). Immediately after the start of the spin-drying process, the vibration threshold value x is reset to a preset initial value x0 (S101). The temperature detection means 25 detects the ambient temperature T of the drum type washing machine 100 (S102), and the vibration threshold value is updated based on the result (S103). If the result of the vibration detection means is less than the vibration threshold value x (S104, Yes), it is determined that the vibration displacement (or the clothes imbalance is acceptable) is acceptable, and the rotation speed of the drum 21 is controlled to be increased (S105). If the vibration displacement is equal to or greater than the vibration threshold value (S104, No), it is determined that the vibration is unacceptable (or the clothes imbalance is unacceptable), and the drum 21 is stopped (S106), and a retry operation is performed (S107). S104 to S107 are repeated until the target rotation speed is reached (S108). After the target rotation speed is reached, dehydration is performed for a predetermined period of time (fixed time) at a constant rotation speed (S109), and after drum 21 is stopped (S110), the dehydration process is terminated.

[0048] Next, the method of updating the vibration threshold value in S103 will be described based on a specific example. The vibration threshold x is updated by the calculation result of a continuous function with the ambient temperature T as a variable. By making it a continuous function with respect to the ambient temperature T, it is possible to obtain a vibration threshold x that is continuous with respect to the temperature during the spin-drying process, and it is possible to appropriately transition to a retry operation in response to abnormal vibration. The vibration threshold x is updated using the update equation defined by equation (1). Equation (1) is a curve described by an n-th degree polynomial with the ambient temperature T as a variable, and is expressed as A0 to A n Its shape is determined by the constant parameters.

[0049]

number

[0050] In order to update the vibration threshold value x with a continuous function corresponding to the ambient temperature T, the constant parameters A0 to A nThis can be realized only by the above, and the vibration threshold value x can be set as a continuous value with respect to the ambient temperature T without having to set the vibration threshold value x corresponding to the ambient temperature T each time.

[0051] In addition, when approximating the vibration threshold value x with a high-order polynomial of the ambient temperature T, it is advisable to perform the power calculation after normalizing the ambient temperature T in equation (1) by dividing it by the reference temperature T0. If the power calculation is performed without performing the above normalization operation, the constant parameter A n There is a possibility that A may take an extremely small value, n This increases the number of digits, which leads to cancellation of digits in computer calculations and consumption of memory in the control unit 7.

[0052] In this embodiment, the continuous function corresponding to the vibration threshold x and the ambient temperature T is approximated by a polynomial, but is not limited to approximation by a polynomial and may be expressed by another continuous function.

[0053] FIG. 5 is a schematic diagram showing the relationship between the vibration threshold value x and the ambient temperature T according to the first embodiment. The curve of the vibration threshold value x and the ambient temperature T shown in FIG. 5 will be taken as an example for explanation. The temperature-dependent characteristics of the rubber feet 1g, the rubber parts of the bellows 16, and the vibration damper 24 used in the drum type washing machine 100 generally exhibit smaller fluctuations in the physical property values ​​with respect to temperature near 0° C. and near 40° C., which are the upper and lower limit temperatures assumed for the use environment of the drum type washing machine 100, compared to those near 20° C. For this reason, it is advisable to set the vibration threshold value x so that the slope of the curve is smaller near the assumed lower and upper limits of temperature.

[0054] Next, the characteristics of the vibration threshold value x according to the temperature condition will be described. At low temperatures, as the damping of the vibration damper 24 increases, the vibration displacement becomes small in the resonance range of the outer tub 11 even if a large clothes imbalance occurs, and as the hardness of the rubber feet 1g increases, abnormal vibration occurs that transmits excessive vibration to the installation floor in the resonance range of the housing 1 and in the range of rotation speeds higher than that.

[0055] For this reason, in the low temperature region (for example, the region below 15°C), the vibration threshold x is designed to have a curve that has a positive correlation with the ambient temperature T, thereby reducing the allowable vibration and suppressing the abnormal vibration described above.

[0056] Next, the concept of the vibration threshold in the high temperature range (for example, the range of 25°C or higher) will be explained. At high temperatures, as the damping of the vibration damper 24 decreases, the allowable clothes imbalance decreases in the resonance range of the outer tub 11, causing excessive retry operations and increasing the time for the spin cycle. Therefore, by giving the vibration threshold x a positive correlation with the ambient temperature T, it is possible to suppress the decrease in the allowable clothes imbalance and contribute to suppressing the increase in the time for the spin cycle.

[0057] After the spin cycle, the rinsing cycle is performed. In this rinsing cycle, the water supply valve 32 is opened, and water supplied from the water supply hose connection port 30 is supplied into the outer tub 11 via the internal water supply hose 31 and the detergent container 12. As in the washing cycle, the greater the calculated laundry volume, the greater the amount of water supplied. In this rinsing cycle, as in the washing cycle, the drum 21 is rotated forward, stopped, reversed, and stopped repeatedly. At this time, an agitation operation is performed for a predetermined period of time, in which the clothes lifted by the baffle 23 fall.

[0058] Thereafter, the spin-drying step and the rinsing step are repeated a predetermined number of times, and then the process proceeds to a final spin-drying step, in which the operation time in the target rotation speed range is set longer than that of the spin-drying step (for example, 300 seconds).

[0059] The drum type washing machine 100 according to the first embodiment includes a housing 1, an outer tub 11 supported within the housing 1 and capable of storing liquid therein, vibration detection means (outer tub vibration detection unit 18) for detecting vibration of the outer tub 11, temperature detection means 25 for detecting the ambient temperature, a motor 22 fixed to the outer tub 11 and generating a driving force for agitating the clothes, and a control unit 7 for controlling the motor 22. The control unit 7 is configured to control the rotation of the motor according to a comparison result between the output of the vibration detection means and a vibration threshold value x representing an allowable vibration, and the vibration threshold value x has a continuous value with respect to the temperature detected by the temperature detection means 25. According to this, the ambient temperature of the drum type washing machine 100 is detected by the temperature detection means 25, and by having a continuous vibration threshold value x with respect to the detected ambient temperature, abnormal vibration can be appropriately suppressed with respect to vibration characteristics that vary with temperature.

[0060] <Second embodiment> In the second embodiment, the differences from the first embodiment will be mainly described. In the second embodiment, the vibration threshold x is expressed as a continuous function with respect to the ambient temperature T as in the first embodiment, but the concept of the vibration threshold in the high temperature region is different.

[0061] Fig. 6 is a schematic diagram showing the relationship between vibration threshold x and ambient temperature T according to the second embodiment. The curve of vibration threshold x and ambient temperature T shown in Fig. 6 will be taken as an example for explanation. A feature of the curve shown in Fig. 6 is that, unlike Fig. 5, in the high temperature region, vibration threshold x has a negative correlation with ambient temperature T.

[0062] The concept of the vibration threshold value x in the high temperature range in FIG. 6 will be explained separately for two cases: detection of vibration of outer tub 11 by outer tub vibration detection unit 18, and detection of clothes imbalance due to rotation fluctuation.

[0063] First, a case where the vibration of the outer tub 11 is detected by the outer tub vibration detection unit 18 will be described. At high temperatures, the hardness of the rubber parts connecting the outer tub 11 and the housing 1, including the bellows 16, decreases. Here, the change in hardness of the rubber parts due to temperature will be described focusing on the bellows 16. In the resonance region of the outer tub shown in Fig. 3, the outer tub 11 passes through multiple vibration modes. At this time, the vibration mode changes according to the change in hardness of the above-mentioned rubber parts.

[0064] FIG. 7 is a schematic diagram showing the difference in vibration mode of the outer tank 11 due to temperature change according to the second embodiment. As a specific example, the difference in vibration mode of the outer tank 11 due to the temperature of the bellows 16 in FIG. 7 at the rotation speed at which the outer tank 11 resonates in the left-right direction will be described. In the low temperature region shown in form 71, the hardness of the bellows 16 increases, so that the front of the outer tank 11 to which the bellows 16 is attached becomes a node, and the element of rotational vibration in which the rear swings more than the front increases. In the high temperature region shown in form 72, the hardness of the bellows 16 decreases, so that the constraint of the outer tank 11 becomes weak, and the element of translational vibration in which the outer tank 11 vibrates in the left-right direction as a whole increases compared to when the temperature is low.

[0065] In the specific example given in Figure 7, the outer tank vibration detection unit 18 is attached to the rear part of the outer tank 11, so that the vibration displacement due to the rotational vibration is added to the output of the outer tank vibration detection unit 18, and the output of the outer tank vibration detection unit 18 is larger at low temperatures than at high temperatures, so it is effective to have the vibration threshold value x negatively correlated with the ambient temperature T in the high temperature range.

[0066] In addition, the outer tub vibration detection unit 18 has been described as being installed at the rear of the outer tub 11 as an example, but this is not limited to being installed at the rear, and the same can be said for the case where it is installed at the front.

[0067] Since the degree of influence of the damping of the vibration damper 24 and the influence of the change in hardness of rubber parts such as the bellows 16 differs in each rotation speed range, the characteristics of Figure 5 or Figure 6 are selected depending on the rotation speed range.

[0068] For example, at the rotation speed at which the outer tub 11 in Fig. 7 resonates in the left-right direction, the hardness of the bellows 16 in the shear direction has a large effect on the vibration mode. Therefore, the vibration mode is likely to change as the hardness of the bellows 16 changes with temperature, and in this case, since the output of the outer tub vibration detection unit 18 becomes small at high temperatures as described above, it is desirable to use the curve in Fig. 6. On the other hand, in the rotation speed range where it can be determined that the effect of the change in hardness of the rubber parts on the vibration mode of the outer tub 11 is small, the curve in Fig. 5 is used.

[0069] Next, a case where clothes imbalance is detected by rotational fluctuation will be described. Since rotational fluctuation is a fluctuation in the rotational speed of the drum 21 caused by the mass distribution of clothes stuck to the drum 21 (clothing imbalance), the output does not vary with the ambient temperature T. Therefore, when designing the vibration threshold x of rotational fluctuation at each temperature, only allowable clothes imbalance needs to be considered.

[0070] In the resonance region of the outer tub 11, the outer tub 11 vibrates greatly, and if it comes into contact with the housing 1, this can lead to abnormal noise and damage to the drum-type washing machine 100, so it is necessary to move to a retry operation before the outer tub 11 comes into contact with the housing 1. In the high temperature region, the damping of the vibration-proof damper 24 is lower than in the medium temperature region (for example, 15°C or higher and lower than 25°C), and even with the same clothes imbalance, the vibration of the outer tub 11 increases in the resonance region of the outer tub 11, and the allowable clothes imbalance (clothes imbalance where the outer tub 11 does not come into contact with the housing 1) decreases compared to the medium temperature region. Since the rotational fluctuation is detected in a lower rotational speed region than the resonance region of the outer tub 11, by setting the vibration threshold value x of the rotational fluctuation in the high temperature region smaller than that in the medium temperature region, it is possible to move to a retry operation without passing the clothes imbalance that is not allowable in the resonance region of the outer tub 11, and to prevent the outer tub 11 from coming into contact with the housing 1. From the above, it is desirable for the vibration threshold value x of the rotational fluctuation to have a curve that has a negative correlation in the high temperature region, as shown in FIG.

[0071] As described above, the vibration threshold x changes from a positive correlation to a negative correlation with the detection result of the temperature detection means as the detection result of the temperature detection means changes from a low temperature to a high temperature with respect to the predetermined temperature. Note that the predetermined temperature is at least one temperature in the above-mentioned medium temperature range (e.g., 15°C or higher and lower than 25°C).

[0072] <Third embodiment> In the third embodiment, a mode in which the vibration threshold value x is updated in accordance with the ambient temperature T while suppressing memory consumption in the control unit 7 will be described. In this embodiment, the vibration threshold x is updated with respect to the ambient temperature T via a threshold coefficient C. The threshold coefficient C represents a correction rate from the initial value x0 of the vibration threshold x with respect to the ambient temperature T, and the vibration threshold x according to the ambient temperature T is obtained by multiplying the initial value x0 of the vibration threshold by the threshold coefficient C as shown in formula (2).

[0073]

number

[0074] The threshold coefficient C is set, for example, as shown in Fig. 8, for a plurality of temperature zones (for example, a first temperature zone to a fifth temperature zone) as threshold coefficients C (for example, C1 to C5). By updating the vibration threshold x via the threshold coefficient C, it becomes possible to update the vibration threshold x according to the temperature while suppressing memory consumption of the control unit 7. The suppression of memory consumption of the control unit 7 will be described below with concrete examples.

[0075] Generally, a user can set start-up settings (e.g., settings 1 to 3) for the spin-drying process of the drum-type washing machine 100, and a different vibration threshold value x is set for each start-up setting. In addition, since the mass of the outer tub 11 changes depending on the amount of clothes put in, even if the same clothes imbalance occurs, the vibration response is different, and therefore a different vibration threshold value x is set according to the clothes capacity. Note that the clothes capacity is classified according to weight rank (e.g., rank 1 (less than 1 kg), rank 2 (1 kg or more and less than 3 kg), rank 3 (3 kg or more and less than 5 kg), rank 4 (5 kg or more)). Therefore, the vibration threshold value x is set for each combination of spin-drying start-up settings and weight ranks (3 x 4 = 12 combinations in this embodiment). ij (Vibration threshold for spin start setting: setting i, weight rank: rank j) is set. Ranks 1 to 4 correspond to the weight of clothes, such as rank 4 being "5 kg or more," but the weight corresponding to the rank varies depending on the specifications of the washing machine. If ranks 1 to 4 are expressed in terms of the amount of clothes, for example, rank 1 would be "small," rank 2 would be "slightly small," rank 3 would be "slightly large," and rank 4 would be "large."

[0076] Fig. 9 is a specific example of a vibration threshold table for each dehydration start setting, weight rank of the clothes volume, and temperature range in a conventional method (comparison example). Fig. 9 shows a comparison example of a method of setting the vibration threshold x for each dehydration start setting, weight rank, and temperature range. To set the vibration threshold x taking into account the temperature range, x is set for each combination of dehydration start setting, weight rank, and each temperature range. ijk (Vibration threshold for spin-dry start setting: setting i, weight rank: rank j, temperature zone: kth temperature zone) must be set. Therefore, to take into account five temperature zones, a total of 60 vibration thresholds x (number of spin-dry start settings x number of weight ranks x number of temperature zones) must be implemented in the memory of the control unit 7, that is, 3 x 4 x 5 combinations.

[0077] FIG. 10 is a specific example of a vibration threshold table for each dehydration start setting, weight rank of the clothes volume, and temperature range according to the third embodiment. FIG. 10 shows the vibration threshold x for each dehydration start setting, weight rank, and temperature range according to the present embodiment. The threshold coefficient C k (The threshold coefficient for the kth temperature range: C k ) to the vibration threshold x ij To update the vibration threshold value x via the threshold coefficient C, the parameter to be implemented in the memory of the control unit 7 is x ij 12 ways and 5 threshold coefficients C k There are a total of 17 parameters. Therefore, by using the threshold coefficient C, it is possible to suppress memory consumption of the control unit 7 compared to the conventional example.

[0078] The drum type washing machine 100 according to the second embodiment includes a housing 1, an outer tub 11 supported within the housing 1 and capable of storing liquid therein, vibration detection means (outer tub vibration detection unit 18) for detecting vibration of the outer tub 11, temperature detection means 25 for detecting the ambient temperature, a motor 22 fixed to the outer tub 11 for generating a driving force for agitating the clothes, and a control unit 7 for controlling the motor 22. The control unit 7 is configured to control the rotation of the motor according to a comparison result between the output of the vibration detection means and a vibration threshold value x representing an allowable vibration, and has a threshold coefficient C calculated from the detection result of the temperature detection means 25, and the vibration threshold value x is calculated based on the threshold coefficient C. This makes it possible to appropriately suppress abnormal vibrations in vibration characteristics that vary with temperature.

[0079] <Fourth embodiment> In the fourth embodiment, an example will be described in which the threshold coefficient C is expressed as a continuous function of the ambient temperature T as shown in equation (3), similar to the vibration threshold x in the first and second embodiments. In addition, a0 to a in formula (3) n is a constant parameter.

[0080]

number

[0081] Fig. 11 shows an example of the relationship between the ambient temperature T and the threshold coefficient C. Unlike Fig. 8, in Fig. 11, the threshold coefficient C takes a continuous value with respect to the ambient temperature T. As described in formula (2), the vibration threshold x is updated by multiplying the threshold coefficient C by the initial value x0 of the vibration threshold, so that it is possible to set the vibration threshold x as a continuous value with respect to the ambient temperature T without having to set the vibration threshold x corresponding to the ambient temperature T each time as in the first and second embodiments.

[0082] The differences between the third and fourth embodiments will be described below with specific examples. In the third embodiment, it is necessary to set a plurality of temperature zones. For example, in the case where five temperature zones are provided, it is necessary to set five threshold coefficients C. In the fourth embodiment, n By simply setting the constant parameters, the threshold coefficient C can be calculated as a continuous value for the ambient temperature T. For example, when setting the threshold coefficient C as a fourth-order polynomial (n=4), five constant parameters are set: a0 to a4.

[0083] When the same five values ​​are set as described above (i.e., the memory consumption of the control unit 7 is the same), in the third embodiment, the vibration threshold x is obtained as five discrete values ​​for the ambient temperature T, and in the fourth embodiment, the vibration threshold x is obtained as a continuous value.

[0084] <Fifth embodiment> In the fifth embodiment, the vibration threshold value x is updated according to the number of times the dehydration process is performed. Fig. 12 is a time chart of the drum rotation speed during the spin-drying cycle of the drum type washing machine 100 according to the fifth embodiment. Fig. 12 shows the time response of the rotation speed of the drum 21 when the spin-drying cycle is performed three times. A method of updating the vibration threshold value x according to the number of spin-drying cycles will be described using the case of Fig. 12 as a specific example.

[0085] In the dehydration step 1 (N=1), the vibration damper 24 performs damping in response to the vibration of the outer tub 11, so that at the timing of transition to the rinsing step 2, the temperature of the vibration damper 24 rises compared to the start of the dehydration step 1. In the rinsing step 2, a rinsing operation is performed for a certain period of time (e.g., 5 minutes). During this period, the temperature of the vibration damper 24 drops because high-speed rotation is not performed, but the vibration damper 24 is stored inside the housing 1 and is hardly exposed to the outside air, so it is not sufficiently cooled. Therefore, the temperature of the vibration damper 24 is higher at the start of the dehydration step 2 (N=2) than at the start of the dehydration step 1, and the damping characteristics are reduced. Similarly, at the start of the dehydration step 3 (N=3), the damping characteristics of the vibration damper 24 are further reduced compared to the start of the dehydration step 2.

[0086] As a result of the above, the damping characteristics of the vibration damper 24 deteriorate with each dehydration cycle, and the vibration of the outer tub 11 increases, reducing the allowable clothes imbalance. Therefore, by setting the vibration threshold to a larger value according to the number of dehydration cycles, the decrease in the allowable clothes imbalance that decreases with the number of dehydration cycles can be mitigated, and the increase in the time required for the dehydration process can be suppressed.

[0087] Fig. 13 is a flowchart for updating the vibration threshold x according to the number of spin-drying steps according to the fifth embodiment. Fig. 13 shows a flowchart for updating the vibration threshold x according to the number of spin-drying steps. In Fig. 13, after the washing step S0201, a first rinsing and spin-drying step S1200, a second rinsing and spin-drying step S2200, and a third rinsing and spin-drying step S3200 are included. This flowchart is executed by the control unit 7 (see Fig. 2).

[0088] After the washing process (S0201) and rinsing process 1 (S1201) are completed, the vibration threshold value x is reset to the initial value x0 (S1202), and the vibration threshold value x is updated according to the ambient temperature T (S1203). The vibration threshold value x in S1203 is updated by multiplying the initial value x0 of the vibration threshold value by the threshold coefficient C, as in equation (2). Then, the spin-drying process 1 is performed (S1204).

[0089] After the rinsing step 2 (S2201) is performed, the vibration threshold is reset to the initial value (S2202), and the vibration threshold x is updated based on the ambient temperature T and the number N of the next spin-dry step (S2203). The update of the vibration threshold x in S2203 is performed by dividing the threshold coefficient C by the update amount based on the ambient temperature T and the update amount C by the number N of spin-dry steps as shown in formula (4). N Then, the dehydration process 2 is performed (S2204).

[0090] After the rinsing step 3 (S3201) is performed, the vibration threshold is reset to the initial value (S3202), and the vibration threshold x is updated based on the ambient temperature T and the number N of the next spin-dry step (S3203). The vibration threshold x is updated in S3203 by dividing the threshold coefficient C by the ambient temperature T and the update C by the number N of spin-dry steps as shown in formula (4). N Then, the dewatering step 3 is performed (S3204), and the drum 21 is stopped (S0202).

[0091]

number

[0092] FIG. 14 is a schematic diagram showing an update amount of the vibration threshold value x according to the number of spin-drying processes according to the fifth embodiment. N An example of the curve is shown below. N is expressed as a continuous function that has a positive correlation with the number of dehydration cycles, for example, as shown in equation (5). In equation (5), α is a constant, and C N This is the parameter that determines the curve.

[0093]

number

[0094] Sixth embodiment In the sixth embodiment, a method of updating the vibration threshold value x according to the clothes imbalance occurring in each spin cycle will be described. Since multiple vibration dampers 24 are arranged at different positions under the outer tub 11, the degree of temperature rise during the spin cycle varies depending on the clothes imbalance. For example, when clothes imbalance occurs behind the drum 21, the temperature rise of the vibration dampers 24 arranged behind the outer tub 11 tends to be greater than that of the dampers arranged in front of the outer tub 11.

[0095] If a clothes imbalance position occurs that is the same as the clothes imbalance position that occurred in the previous spin-drying process, the temperature of the already heated vibration damper 24 will rise further, so the vibration threshold value x is updated to be larger in order to prevent a decrease in the allowable clothes imbalance, and the increase in time in the spin-drying process is suppressed.

[0096] Fig. 15 is a flowchart for updating the vibration threshold in response to clothing imbalance according to the sixth embodiment. Fig. 15 shows a flowchart for updating the vibration threshold in response to clothing imbalance. This flowchart is executed by the control unit 7 (see Fig. 2). The control unit has a clothing imbalance determination unit that determines clothing imbalance, and determines clothing imbalance.

[0097] First, as in the flowchart of Fig. 4, the vibration threshold x is reset to an initial value (S301), and then the vibration threshold x is updated based on the ambient temperature T (S302). A determination is made as to whether the spin cycle number is the second or later (S303). If the spin cycle number is the first (S303, No), the vibration threshold x is not updated in response to the clothes imbalance, and the process moves to a determination of a retry operation (S307). If the spin cycle number is the second or later (S303, Yes), the process proceeds to S304, where the vibration threshold is updated in response to the clothes imbalance.

[0098] First, the position of unbalanced clothes is determined using the result of the vibration detection means (S304). In determining the position of unbalanced clothes (S304), for example, the outer tub vibration detection unit 18 capable of detecting vibration displacement (or acceleration) in multiple directions can be used to determine the position from the phase difference or maximum value ratio of the output values ​​of each axis, and the configuration is not limited.

[0099] Next, it is determined whether the clothes imbalance position determination result matches the clothes imbalance position stored in the previous spin cycle (S305), and if they match (S305, Yes), the vibration threshold is updated according to the recorded clothes imbalance amount (S306). The method of updating the vibration threshold according to the clothes imbalance amount in S306 is set so that the larger the clothes imbalance amount generated in the previous spin cycle, the larger the temperature rise of the vibration damper 24 becomes.

[0100] If the result of the determination of the clothes imbalance position does not match the clothes imbalance position stored in the previous spin cycle (S305, No), the vibration threshold is not updated, and the process proceeds to a retry operation determination (S307).

[0101] In S307, it is determined whether the result of the vibration detection means is less than the vibration threshold value x. If the result of the vibration detection means is not less than the vibration threshold value x (S307, No), the drum 21 is stopped (S309), a retry operation is performed (S310), and the process proceeds to S307.

[0102] If it is not necessary to perform a retry operation (S307, Yes), the rotation speed of the drum 21 is increased (S308). It is determined whether the target rotation speed has been reached (S311), and if the target rotation speed has not been reached (S311, No), the process returns to S303.

[0103] If the target rotation speed is reached (S311, Yes), the position and amount of clothes imbalance are determined again after the target rotation speed is reached, and the data is overwritten in the memory of the control unit 7 (S312). The reason for determining the amount and position of clothes imbalance after the target rotation speed is reached is that this is the region where spin-drying is performed at high speed for a long period of time, and therefore the temperature rise of the vibration damper 24 is the largest. After spin-drying is performed for a certain period of time (S313), the drum 21 is stopped (S314), and the spin-drying process is completed.

[0104] In the present invention, several embodiments have been described, but in these embodiments, when updating the vibration threshold value x so that it is larger than the initial value x0, it is necessary to perform the update within a range where the outer tub 11 and the housing 1 do not come into contact with each other. Therefore, the threshold coefficient C and the correction amount C according to the number of spin cycles are N It is desirable to set an upper limit for the amount of correction for the clothing imbalance. [Explanation of symbols]

[0105] 1 Case 10 Rotational speed detection device 11 Outer tank 16 Bellows 18 Outer tank vibration detection unit (vibration detection means) 21 Drums 22 Motor 24 Anti-vibration damper 25 Temperature detection means 100 Drum type washing machine (washing machine) A0,…,A n Constant parameters a0,…,a n Constant parameters C Threshold coefficient C N Updates N Number of dehydration T Ambient temperature T0 reference temperature x Vibration Threshold x0 initial value

Claims

1. A housing and an outer tank supported within the housing and capable of storing a liquid therein; A vibration detection means for detecting vibration of the outer tank; A temperature detection means for detecting an ambient temperature; A motor fixed to the outer tub for generating a driving force for agitating the clothes; A control unit for controlling the motor, the control unit is configured to control the rotation of the motor in response to a comparison result between an output of the vibration detection means and a vibration threshold value that indicates an allowable vibration; The vibration threshold has a continuous value with respect to the temperature detected by the temperature detection means. A washing machine characterized by:

2. A housing and an outer tank supported within the housing and capable of storing a liquid therein; A vibration detection means for detecting vibration of the outer tank; A temperature detection means for detecting an ambient temperature; A motor fixed to the outer tub for generating a driving force for agitating the clothes; A control unit for controlling the motor, the control unit is configured to control the rotation of the motor in response to a comparison result between an output of the vibration detection means and a vibration threshold value that indicates an allowable vibration; A threshold coefficient is calculated based on the detection result of the temperature detection means, The vibration threshold is calculated based on the threshold coefficient. A washing machine characterized by:

3. The washing machine according to claim 1, The vibration threshold has a negative correlation with the detection result of the temperature detection means. A washing machine characterized by:

4. The washing machine according to claim 3, The vibration threshold value transitions from a positive correlation to a negative correlation with the detection result of the temperature detection means as the detection result of the temperature detection means changes from a low temperature to a high temperature with respect to a predetermined temperature. A washing machine characterized by:

5. The washing machine according to claim 2, The vibration threshold has a negative correlation with the detection result of the temperature detection means. A washing machine characterized by:

6. The washing machine according to claim 5, The vibration threshold value transitions from a positive correlation to a negative correlation with the detection result of the temperature detection means as the detection result of the temperature detection means changes from a low temperature to a high temperature with respect to a predetermined temperature. A washing machine characterized by:

7. The washing machine according to any one of claims 1 to 6, The vibration threshold varies depending on the number of spin cycles. A washing machine characterized by:

8. The washing machine according to any one of claims 1 to 6, The control unit has a clothing imbalance determination unit that determines clothing imbalance, The vibration threshold value is changed depending on the result of the determination by the clothes imbalance determination unit and the result of the determination by the clothes imbalance determination unit in the past dehydration process. A washing machine characterized by:

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