Washing machine

Abstract

To make it possible to measure a load of a washing machine with high accuracy, while enduring a high load.SOLUTION: A drum-type washing machine 1 includes a housing 2 which has a plurality of leg parts 20. The leg part 20 includes: a reinforcement bracket 22 mounted on a lower surface of the housing 2; a support leg 21 for supporting the housing 2 in a state of having a gap on a floor surface F; and a load measuring instrument 50 for measuring a load acting on the leg part 20. The load measuring instrument 50 is integrated with the reinforcement bracket 22 and the support leg 21 so as to be interposed between the reinforcement bracket 22 and the support leg 21, in a state of being positioned between the lower surface of the housing 2 and the reinforcement bracket 22.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosed technology relates to a washing machine and technologies for suppressing an increase in casing vibration due to resonance and accurately measuring the weight of laundry or the like.

Background Art

[0002] Generally, a dryer is installed on top of a washing machine to form a unit. In such a case, the load applied to the legs of the washing machine increases significantly compared to the washing machine alone, and as the load increases, the resonance frequency with the floor surface decreases. During the dehydration of the washing machine, when the dehydration rotation speed matches the resonance frequency, the casing vibration is likely to increase. During dehydration, there is a period when the dehydration rotation speed is kept constant in consideration of the time for water to drain from the clothes. In particular, when the dehydration rotation speed matches the resonance frequency in this constant period, a washing machine-dryer unit with a high overall height will shake more during the constant period compared to the washing machine alone, and a large amount of noise will also be generated.

[0003] Also, in order to realize efficient operation of the washing machine, it is important to accurately measure the weight (fabric amount) of the laundry before the washing process. Therefore, in a conventional drum-type washing machine, generally, the drum containing the laundry is rotated, and the fabric amount is estimated based on its moment of inertia. However, this method has a problem that the accuracy decreases as the fabric amount increases.

[0004] On the other hand, Patent Document 1 proposes a washing machine that can directly measure the fabric amount instead of estimating it.

[0005] A vertical washing machine with a weight sensor attached to the legs of the washing machine body is disclosed therein. In that washing machine, the weight of the laundry put in is measured by the weight sensor. The weight sensor utilizes the resistance change due to the piezoresistive effect of a semiconductor strain gauge and is a semiconductor pressure sensor that converts the strain of the diaphragm in the weight sensor into an electrical signal. Since it measures directly, the fabric amount can be accurately measured.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In this method, in addition to being able to measure the amount of cloth with high precision, the levelness of the washing machine can be detected, so that highly accurate positioning of the washing machine becomes possible. Furthermore, according to the findings of the present inventors, it is also possible to detect an increase in the vibration of the housing due to the resonance of the washing machine / dryer unit, and in particular, it is also possible to avoid coincidence with the resonance frequency in the section where the dehydration rotation speed is kept constant.

[0008] However, since the load applied to the legs of the washing machine is large, the weight sensor is required to have sufficient strength and rigidity to withstand it while protecting the structure of its delicate detection part. This is even more the case for a washing machine / dryer unit. Even if sufficient strength and rigidity can be ensured, if the structure becomes complex, the assembly workability deteriorates and it becomes unsuitable for mass production. In addition, a transport platform, a fork, etc. are often inserted under the washing machine during transportation or installation, etc., and there is also a risk that the weight sensor may be damaged by contact with them.

[0009] Therefore, the disclosed technology aims to provide a washing machine that can accurately measure the load of the washing machine while ensuring sufficient strength and rigidity to withstand high weights and is also suitable for mass production.

Means for Solving the Problems

[0010] The disclosed technology relates to a washing machine including a housing having a plurality of legs on its bottom surface.

[0011] The leg portion has a reinforcing bracket attached to the lower surface of the housing, a support leg that supports the housing with a gap on the floor surface, and a load measuring device that measures the load acting on the leg portion. And the load measuring device is integrated with the reinforcing bracket and the support leg so as to be interposed between the reinforcing bracket and the support leg while being positioned between the lower surface of the housing and the reinforcing bracket.

[0012] That is, according to this washing machine, since each leg portion that supports the housing has a load measuring device, as described above, the amount of laundry can be measured with high accuracy, and the height of the leg portion can be adjusted. Further, since the leg portion is reinforced by the reinforcing bracket in a state including the load measuring device, strength and rigidity that can withstand high weight can also be ensured.

[0013] And the load measuring device is integrated with the reinforcing bracket and the support leg so as to be interposed between the reinforcing bracket and the support leg while being positioned between the lower surface of the housing and the reinforcing bracket. Therefore, even if a carrier or a fork is inserted under the washing machine, it is protected by the reinforcing bracket, so that damage to the load measuring device due to contact with them can be prevented. Moreover, since the load measuring device is integrated while being interposed between the reinforcing bracket and the support leg, it is easy to assemble and remove from the housing, has excellent mass productivity, and is also easy to replace.

[0014] The load measuring device may have a strain generating body that supports the support leg at an intermediate portion thereof with both ends fixed to the reinforcing bracket, a strain gauge attached to the strain generating body to detect the strain of the strain generating body, and a wire guide attached to the reinforcing bracket to support an amplifier circuit, and a lead wire connecting the strain gauge and the amplifier circuit is attached to the wire guide so as to extend along the surface of the wire guide.

[0015] If so, since the strain body is supported at both ends by the reinforcing brackets, it is relatively easy to ensure the strength and rigidity to withstand high weights. And since the support leg is supported at the middle part thereof, the load acting on the leg can be received by the strain body as it is. Therefore, the strain body is liable to be distorted, and the measurement accuracy of the load can be improved.

[0016] Moreover, when connecting the lead wire to the strain gauge, due to its relationship with the size, the wire diameter of the lead wire has to be small and delicate. Therefore, it is liable to break, but since it is attached along the surface of the wire guide, the lead wire can be protected.

[0017] It may be that the strain body is made of chrome molybdenum steel. And in that case, it is preferable that the surface of the strain body is subjected to rust prevention treatment.

[0018] A high load acts on the strain body. Therefore, by using chrome molybdenum steel excellent in strength and rigidity as the material of the strain body, the strain body can be formed into a thin plate shape, and the leg part can be made compact. On the other hand, corrosion resistance is required in the washing machine, but when chrome molybdenum steel is not subjected to rust prevention treatment, its corrosion resistance is lower than that of stainless steel or the like. However, if the surface of the strain body is subjected to rust prevention treatment, high rigidity and high strength can be compatible with corrosion resistance.

[0019] The support leg may have a screw shaft part and a grounding plate attached to the lower end of the screw shaft part, and the screw shaft part may be pivotally supported in a vertically movable state by a pivot boss fixed to the strain body.

[0020] If so, the height of the leg can be adjusted by the support leg. In combination with the detection of the level by the load measuring instrument, highly accurate positioning of the washing machine can be achieved.

[0021] The washing machine further includes a water storage tank accommodated in the housing, a drum rotatably accommodated in the tank, a driving device for rotating the drum, a water supply device for supplying water to the tank, a drainage device for draining water from the tank, and a control device for controlling the driving device, the water supply device, and the drainage device. The control device may execute a cloth quantity measurement process for measuring the weight of the laundry accommodated in the drum based on the measurement result of the load measuring device.

[0022] As described above, since the weight of the laundry can be accurately measured in real time by the load measuring devices of each leg, this washing machine can perform advanced washing processes.

[0023] Furthermore, when an additional device such as a dryer is placed on the washing machine, the control device may execute a resonance vibration suppression process for avoiding an increase in resonance vibration during the dehydration process based on the measurement result of the load measuring device.

[0024] As described above, when an additional device such as a dryer is placed on the washing machine, an increase in housing vibration may continuously occur due to resonance during a certain range of the dehydration rotation speed. However, an increase in the housing vibration can be detected from the measurement result of the load measuring device. Therefore, according to this washing machine, the rotation speed within a certain range of the dehydration rotation speed can be controlled while avoiding the resonance frequency, so that the performance can be improved.

Advantages of the Invention

[0025] According to the disclosed technology, while ensuring the strength and rigidity capable of withstanding high loads, the load of the washing machine can be accurately measured, so that an increase in housing vibration due to resonance and the weight of the laundry and the like can be accurately measured. Moreover, since the assembly workability is excellent, the mass production adaptability can also be improved.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0027] Hereinafter, the technology disclosed by the embodiments will be described. However, the following description is merely illustrative in nature.

[0028] <Overall Structure of the Drum - type Washing Machine> FIG. 1 shows a drum - type washing machine (hereinafter, also simply referred to as washing machine 1) to which the disclosed technology is applied.

[0029] This washing machine 1 is a so - called fully automatic washing machine and is configured to be able to automatically perform a series of processes of washing, rinsing, and dehydration. Note that this washing machine 1 is not equipped with a drying function. Therefore, as will be described later, it is configured to be unitized (washing machine - dryer unit) by combining with a dryer having a unified design with the washing machine 1 (see FIG. 8).

[0030] The washing machine 1 is composed of a housing 2, a tub 3, a drum 4, a drive device 5, a water supply device 6, a drainage device 7, a control device 8, etc.

[0031] The housing 2 is formed in a rectangular parallelepiped shape by assembling a panel or the like to a frame. A circular inlet 2a that is opened and closed by a door is provided on the front surface of the housing 2. Laundry is put in and taken out through this inlet 2a. Above the inlet 2a, an operation unit 2b that a user operates to operate the washing machine 1, such as a switch and a monitor, is provided.

[0032] At four corner portions on the front, rear, left, and right of the lower surface of the housing 2, legs 20 that support the housing 2 are respectively attached. The housing 2 is installed on the floor surface F with a gap via these legs 20. In the case of this washing machine 1, in order to improve the washing performance, a load measuring device 50 that enables highly accurate measurement of the laundry and the water supply amount accommodated in the drum 4 is incorporated in these legs 20. The legs 20 will be described separately later.

[0033] The tub 3 is composed of a bottomed cylindrical container capable of storing water. The tub 3 has an annular front wall portion 3a formed with an opening having substantially the same diameter as the inlet 2a, a disk-shaped rear wall portion 3b facing the front wall portion 3a, and a cylindrical body wall portion 3c interposed therebetween. The tub 3 is housed in the housing 2 in a horizontally placed state with the front wall portion 3a facing forward.

[0034] The front wall portion 3a is connected to the front surface of the housing 2 via an elastically deformable annular seal 10, and the space between the inlet 2a and the tub 3 is sealed by the annular seal 10. A shaft 11 is pivotally supported at the center of the rear wall portion 3b, and a drive device 5 composed of a motor 5a, a pulley 5b, a belt, etc. that rotates the shaft 11 is assembled to the tub 3. The pulley 5b and the belt are attached to the rear wall portion 3b, and the motor 5a is attached to the rear side of the lower part of the tub 3, respectively.

[0035] The tab 3 is elastically supported by the housing 2 in order to suppress the transmission of vibrations generated during washing and dehydration to the outside of the washing machine 1. That is, a pair of suspension springs 12 are attached to the left and right sides on the upper inner side of the housing 2, and the tab 3 is suspended by these suspension springs 12. Further, dampers 13 are attached to four locations on the front, rear, left, and right sides on the lower inner side of the housing 2, and the tab 3 is also supported by these four dampers 13.

[0036] The drum 4 is composed of a bottomed cylindrical container that is slightly smaller than the tab 3, and is housed in the tab 3 in a horizontally placed state with its opening facing forward. The tip of the shaft 11 protruding forward of the rear wall portion 3b is fixed to the center of the rear portion of the drum 4, and the drum 4 is also rotatably housed in the tab 3. A large number of water passing holes 4a penetrating inside and outside are formed over the entire circumferential surface of the drum 4 (only a part is shown in FIG. 1).

[0037] The drum 4 and the tab 3 are arranged such that their center lines coincide, and the inlet 2a, and the openings of the tab 3 and the drum 4 overlap in the front-rear direction and are configured to communicate with each other. The drum 4 rotates inside the tab 3 about a substantially horizontal rotation axis J by the drive of the motor 5a.

[0038] A water supply device 6 is installed at the upper part of the housing 2. Although specific illustration of the water supply device 6 is omitted, it is composed of an electromagnetic on-off valve, a water supply hose, etc., and is configured to supply water from an external water supply facility or the like to the tab 3.

[0039] A drain hose 7a is connected to the drain port provided at the lower end of the tab 3. The end of the drain hose 7a is led out to the outside of the housing 2. A pump may be provided in the drain hose 7a to drain water by the pump. The drain hose 7a constitutes the drainage device 7.

[0040] As shown by the phantom line in Fig. 1, the control device 8 is installed inside the housing 2. The control device 8 comprehensively controls the operation of the washing machine 1 according to the operation on the operation unit 2b. That is, the control device 8 controls the operations of the drive device 5, the water supply device 6, and the drainage device 7 to execute a series of processes including washing, rinsing, and dehydration.

[0041] Particularly in the case of this washing machine 1, the control device 8 is capable of executing processes such as measuring the weight of the laundry accommodated in the drum 4 (fabric amount measurement process) based on the measurement results of the load measuring device 50, and is configured to improve the washing performance (details will be described later).

[0042] <Leg portion 20> As described above, in this washing machine 1, load measuring devices 50 are installed on each leg portion 20 in order to enable measurement of the laundry accommodated in the drum 4 and the water supply amount. The load measuring device 50 measures the load acting on each leg portion 20.

[0043] Fig. 2 shows a schematic cross-sectional view seen from the side of the leg portion 20. Originally, each leg portion 20 of this washing machine 1 is composed of a support leg 21 and a reinforcing bracket 22. The support leg 21 is a member that supports the housing 2 with a gap on the floor surface F. The reinforcing bracket 22 is a plate-shaped member attached to the lower surface of the housing 2 by fastening a fixing bolt 23, and reinforces the rigidity and strength of the peripheral portion of the leg portion 20 in the housing 2.

[0044] At the attachment site of each leg portion 20 in the housing 2, a receiving recess 14 that is recessed upward is formed. The receiving recess 14 is formed slightly larger than the thickness of the load measuring device 50 (particularly the strain generating body 52) and the contour seen from above. The load measuring device 50 is accommodated in this receiving recess 14 in a state of being positioned between the lower surface of the housing 2 and the reinforcing bracket 22 and intervening between the reinforcing bracket 22 and the support leg 21.

[0045] Therefore, even if the load measuring device 50 is additionally incorporated in the leg portion 20, the height of the leg portion 20 is almost the same as when the load measuring device 50 is not present, and it does not affect the size of the washing machine 1. That is, the disclosed technology is excellent in versatility.

[0046] Under the washing machine 1, a transport table, a fork, etc. are often inserted during transportation or installation. At that time, if they come into contact with them, there is a risk of damaging the delicate load measuring device 50. On the other hand, since the lower side of the load measuring device 50 is protected by the reinforcing bracket 22, damage to the load measuring device 50 can be suppressed.

[0047] And the load measuring device 50 is incorporated and integrated into these support legs 21 and reinforcing brackets 22 (hereinafter, the leg portion 20 is also referred to as the unit leg portion 20). Therefore, by simply attaching the unit leg portion 20 to the housing 2, the load measuring device 50 can be attached to the housing 2 together with the leg portion 20.

[0048] (Unit leg portion 20) FIG. 3 shows a schematic perspective sectional view of the unit leg portion 20 in a state of being attached to the housing 2. FIG. 4 shows a schematic overall perspective view of the unit leg portion 20. FIG. 5 shows a schematic exploded perspective view of the unit leg portion 20.

[0049] As shown in FIG. 5 and the like, the unit leg portion 20 is composed of a strain gauge 51, a strain generating body 52, a shaft support boss 24, a wire guide 53, an amplifier circuit 54, a reinforcing bracket 22, a support leg 21, etc. Among these, the load measuring device 50 is composed of a strain gauge 51, a strain generating body 52, a wire guide 53, an amplifier circuit 54, etc.

[0050] The strain gauge 51 is a known member. The strain gauge 51 is used to detect the strain of the strain generating body 52 and can be appropriately selected according to the specifications. In this washing machine 1, a strain gauge 51 having two strain detection elements 51a, 51a on a rectangular base is used. A half-bridge circuit is constituted by the two strain detection elements 51a, 51a.

[0051] The warping body 52 is made of an elongated thin plate-like member with excellent rigidity and strength. In particular, in the case of this washing machine 1, as will be described later, since the dryer 60 may be placed thereon, the load-bearing capacity per leg 201 is required to be, for example, 100 kg or more. In order to withstand this with a thin plate-like predetermined shape, high rigidity and high strength are required, and chromium molybdenum steel (for example, SCM440) is used as the material of the warping body 52.

[0052] On the other hand, in the case of the washing machine 1, corrosion resistance is also required. In contrast, chromium molybdenum steel may rust, and it is preferable to perform rust prevention treatment. Therefore, by applying nickel plating to the surface of the warping body 52, high rigidity, high strength, and corrosion resistance can be achieved simultaneously.

[0053] The warping body 52 has a base portion 52b in which a hexagonal hole 52a is formed, and a pair of arm portions 52d, 52d that extend in opposite directions from both sides of the base portion 52b and in which screw holes 52c are formed at the tip portions. Strain gauges 51 are attached to the upper surfaces of the respective arm portions 52d. That is, one warping body 52 has two strain gauges 51.

[0054] And each strain gauge 51 is arranged such that two strain detection elements 51a, 51a are arranged side by side in the longitudinal direction of the arm portion 52d, and both the elongation and contraction of the warping body 52 can be measured by these strain detection elements 51a, 51a. Thereby, a full bridge circuit is constituted by the four strain detection elements 51a included in one warping body 52.

[0055] The shaft support boss 24 is made of a hexagonal columnar member having a flange at the lower end, and a shaft hole 24a for inserting the screw shaft portion 21a is formed at the center thereof. The shaft support boss 24 is inserted into the hexagonal hole 52a from below by pressing and fixed to the warping body 52 in a non-rotatable state.

[0056] The support leg 21 is composed of a screw shaft portion 21a, a grounding plate 21b, a fixing member 21c, etc. The screw shaft portion 21a is a cylindrical part, and a male screw is formed on its outer peripheral surface. The screw shaft portion 21a is pivotally supported by the pivot boss 24 in a vertically movable state.

[0057] At the lower end of the screw shaft portion 21a, a grounding plate 21b formed in a hexagonal plate shape and in contact with the floor surface F is rotatably attached. The fixing member 21c is a cylindrical member having a nut, and a female screw is formed on its inner surface and is screwed onto the screw shaft portion 21a.

[0058] As shown in FIG. 5, the reinforcing bracket 22 is a plate-like member excellent in rigidity and strength, and is formed in a predetermined shape according to the shape of the lower surface of the housing 2. On its plate surface, two fastening holes 22a, two mounting holes 22b, and one shaft opening 22c are formed at predetermined positions respectively. The inner diameter of the shaft opening 22c is formed larger than that of the pivot boss 24 and the fixing member 21c.

[0059] As shown in FIG. 2, the fixing bolts 23 inserted from below each of the fastening holes 22a are fastened to the lower surface of the housing 2. By doing so, the reinforcing bracket 22 is fixed to the housing 2 as described above. Instead of the fixing bolts 23, it may be fixed with rivets or the like.

[0060] As shown in FIGS. 2 and 3, the strain generating body 52 with the pivot boss 24 fixed is placed on the upper side of the reinforcing bracket 22, and is fixed to the reinforcing bracket 22 by fastening the mounting bolts 25 inserted from below each of the mounting holes 22b to the screw holes 52c. Thereby, the strain generating body 52 supports the support leg 21 via the pivot boss 24 fixed to the middle part thereof in a state where both ends thereof are fixed to the reinforcing bracket 22.

[0061] That is, since both ends of the strain generating body 52 are supported by the reinforcing brackets 22, it is possible to ensure rigidity and strength corresponding to high loads while detecting delicate strains. The strain generating body 52 is attached above the reinforcing brackets 22 and is accommodated in the accommodation recess 14 between the housing 2 and the reinforcing brackets 22 when the unit leg portion 20 is attached to the housing 2, so that the strain generating body 52 can be effectively protected.

[0062] The support leg 21 is supported by the reinforcing bracket 22 via the strain generating body 52 that is not in contact with the housing 2. Therefore, since all the loads acting on the leg portion 20 act on the strain generating body 52, the load can be measured with high accuracy.

[0063] As shown in FIG. 5, the wire guide 53 is made of a plastic member having a strip shape and is composed of a main part 53a and a sub-part 53b assembled to one end side of the main part 53a. An amplifier circuit 54 is attached to the upper surface of the other end side of the main part 53a. As shown in FIG. 3, the amplifier circuit 54 is configured to be located inside the housing 2 through an opening in the lower surface of the housing 2 when the unit leg portion 20 is attached to the housing 2.

[0064] A lead wire accommodating portion 53c for accommodating a plurality of fine wire diameter first lead wires 55 (see FIG. 5) extending from each strain gauge 51 is formed at one end side of the main part 53a. The sub-part 53b is assembled to the main part 53a by screwing so as to cover the upper side of the lead wire accommodating portion 53c. The wire guide 53 is attached by screwing to the upper side of the reinforcing bracket 22 so that the lead wire accommodating portion 53c is along the side of the strain generating body 52.

[0065] Each of the first lead wires 55 is drawn out from the inside of the lead wire accommodating portion 53c and is attached to the main part 53a along the upper surface of the main part 53a and connected to the input terminal of the amplifier circuit 54 as shown in FIG. 4.

[0066] The wire guide 53 is also attached above the reinforcing bracket 22, similar to the strain generating body 52. Therefore, when the unit leg portion 20 is attached to the housing 2, one end side thereof is positioned between the housing 2 and the reinforcing bracket 22. Accordingly, the wire guide 53 can also be effectively protected, and the disconnection of the first lead wire 55 can be prevented.

[0067] A second lead wire 56 having a relatively large wire diameter corresponding to the specifications of the washing machine 1 is connected to the output terminal of the amplifier circuit 54. Accordingly, the first lead wire 55 can be effectively protected even if it has a small wire diameter. The amplifier circuit 54 amplifies the weak output voltage input from each strain detection element 51a and outputs it to the control device.

[0068] FIG. 6 illustrates the circuit configuration of the load measuring device 50 provided in the washing machine 1. In each of the load measuring devices 50 of the four leg portions 20 located on the front, rear, left, and right of the housing 2, a full bridge circuit is configured by four strain detection elements 51a. The control device 8 measures the load acting on each leg portion 20 from the measurement values of these full bridge circuits.

[0069] That is, R1, R2, R3, and R4 correspond to the four strain detection elements 51a of the two strain gauges 51 attached to each of the load detectors 50. The full bridge circuit of each load measuring device 50 is connected to the control device 8 via the amplifier circuit 54.

[0070] When R1 and R4 contract, R2 and R3 expand, and when R1 and R4 expand, R2 and R3 contract. A predetermined voltage (applied voltage) is input between P1 and P2 of the full bridge circuit, and the voltage (output voltage) between P3 and P4 is output to the amplifier circuit 54. After the applied voltage and the output voltage are amplified by the amplifier circuit 54 (V1 to V4), they are output to the control device 8.

[0071] The control device 8 calculates the load acting on each leg 20 based on the voltage values V1 to V4 input from each load measuring device 50 in this way. Then, the control device measures the amount of laundry based on the change in the load acting on each leg 20 and avoids an increase in the vibration of the housing generated by resonance.

[0072] Fig. 7 shows a block diagram representing the relationship between the control device 8 and the main devices. The control device 8 is provided with an operation control unit 8a, a laundry amount measuring unit 8b, a resonance vibration suppression unit 8c, etc. as functional configurations.

[0073] The operation control unit 8a comprehensively controls the operation of the washing machine 1 according to the operation on the operation unit 2b. That is, the control device 8 controls the operations of the drive device 5, the water supply device 6, and the drainage device 7 to execute a series of processes including washing, rinsing, and dehydration.

[0074] The laundry amount measuring unit 8b measures the amount of laundry based on the signals input from each load measuring device 50 (laundry amount measuring process). Specifically, when laundry is put into the drum 4, the laundry amount measuring unit 8b measures the laundry amount from the change in the load of each leg 20 accompanying it. Since the change in the load of the washing machine 1 can be measured based on the loads acting on the four load measuring devices 50, the laundry amount can be measured directly and with high accuracy.

[0075] Note that the control device 8 can also measure the water supply amount based on the load acting on each leg 20, so advanced washing can be performed. Furthermore, since the levelness of the washing machine 1 can also be measured, highly accurate positioning of the washing machine 1 can be achieved.

[0076] As described above, this washing machine 1 can be configured as a washing machine - dryer unit by placing a predetermined dryer 60 (an example of an attached device) on it. Fig. 8 illustrates the washing machine - dryer unit.

[0077] When such a washing and drying machine unit is configured, the load acting on each leg 20 can exceed 100 kg (for example, 130 kg). Therefore, as described above, each leg 20 requires rigidity and strength that it can withstand. Further, during the dehydration process, due to the influence of the decrease in the resonance frequency with the floor surface caused by the increase in the load, especially in a section where the dehydration rotation speed is constant, the dehydration rotation speed and the resonance frequency match, and the possibility of an increase in the vibration of the housing becomes high. In such a case, in a vertically long and heavy washing and drying machine unit, there is a risk of giving the user discomfort and uneasiness due to large noise and vibration.

[0078] On the other hand, in this washing machine 1, it is devised to be able to avoid matching with the resonance frequency in the section where the dehydration rotation speed is kept constant by using the load measuring device 50. That is, the resonance vibration suppression unit 8c detects the occurrence of an increase in the vibration of the housing due to resonance based on the measurement result of the load measuring device 50, and avoids such an increase in the vibration of the housing (resonance vibration suppression process). Thereby, it becomes possible to minimize the time when large vibrations and noises occur, for example, by changing the rotation speed set as the constant dehydration rotation speed section of the drum 4.

[0079] <Suppression of increase in housing vibration due to resonance> FIG. 9 shows an example of test results regarding the suppression of the increase in the vibration of the housing due to resonance, that is, resonance vibration. The left graph in FIG. 9 shows the change over time of the drum rotation speed during the dehydration process in a predetermined washing and drying machine unit. And the range R indicated by the diagonal lines represents the resonance frequency band between the floor surface of the washing and drying machine unit and the unit.

[0080] The upper right graph (a) in FIG. 9 shows the change over time of the load measured by one leg 20 during the dehydration process shown in the left graph. The lower right graph (b) in FIG. 9 shows the change over time of the total value of the loads measured by the four legs 20 during the dehydration process shown in the left graph (corresponding to the load change of the washing machine 1 so-called).

[0081] As shown by arrow Y1, when looking at the amplitude of the load after 200 seconds, an increase can be observed in the case of one leg, while no increase is observed in the case of four legs. That is, in the case of four legs, it is possible that an increase in the vibration of the housing due to resonance cannot be detected because the increase and decrease of the load cancel each other out. Therefore, the resonance vibration suppression unit 8c of this washing machine 1 is configured to avoid an increase in the vibration of the housing based on the measured value of any one of the load measuring devices 50.

[0082] Note that the disclosed technology is not limited to the above-described embodiments and includes various other configurations. For example, the washing machine may not be limited to a drum type and may be vertical. The above-described strain body 52 is in the form of a thin plate with a constant thickness, but grooves extending along the short side may be formed on the lower surface of each arm portion 52d facing between the two strain detection elements 51a. In that case, the strain body 52 becomes more prone to strain, so the sensitivity of the strain gauge 51 can be improved.

[0083] What is placed on the washing machine 1 is not limited to the dryer 60. For example, it may be a shelf or other device. The above-described strain body 52 is supported at two points at both ends, but in the case of a cross-shaped or disc-shaped strain body, etc., it may be supported at a plurality of points of three or more. When the amplifier circuit 54 can be arranged near the support leg 21, the wire guide 53 may be in the form of a rectangular plate, or the wire guide 53 may be omitted and attached to the reinforcing bracket 22.

[0084] Also, the amplifier circuit 54 may not be provided for each unit leg 20, but may be provided one between the control device 8 itself or between the control device 8 and each leg 20. In that case, instead of the amplifier circuit 54, a relay terminal for relaying the lead wire may be installed on the wire guide 53.

Explanation of Reference Numerals

[0085] 1 Drum-type washing machine 2 Housing 2a Loading port 2b Operation unit 3 Tab 4 Drum 5 Driving device 5a Motor 5b Pulley 6 Water supply device 7 Drainage device 8a Operation control unit 8b Fabric quantity measurement unit 8c Resonance vibration suppression unit 11 Shaft 12 Suspension spring 13 Damper 14 Accommodation recess 20 Legs (unit legs) 21 Support leg 22 Reinforcing bracket 23 Fixing bolt 24 Axle support boss 50 Load measuring instrument 51 Strain gauge 51a Strain detection element 52 Distortion body 53 Wire guide 54 Amplifier circuit F Floor surface

Claims

1. A washing machine comprising a housing having a plurality of legs below, wherein the legs include, a reinforcing bracket attached to the lower surface of the housing, a support leg that supports the housing with a gap on the floor surface, a load measuring device that measures the load acting on the legs, and having, the load measuring device is integrated with the reinforcing bracket and the support leg so as to be interposed between the reinforcing bracket and the support leg while being positioned between the lower surface of the housing and the reinforcing bracket. A washing machine.

2. In the washing machine according to Claim 1, the load measuring device includes, a strain generating body that supports the support leg at an intermediate portion thereof with both ends fixed to the reinforcing bracket, a strain gauge attached to the strain generating body to detect the strain of the strain generating body, a wire guide attached to the reinforcing bracket to support an amplifier circuit, and having, a lead wire connecting the strain gauge and the amplifier circuit is attached to the wire guide so as to extend along the surface of the wire guide. A washing machine.

3. In the washing machine according to Claim 2, the strain generating body is made of chrome molybdenum steel. A washing machine.

4. In the washing machine according to Claim 3, a rust prevention treatment is applied to the surface of the strain generating body. A washing machine.

5. In the washing machine according to Claim 2, the support leg includes, a screw shaft portion, a grounding plate attached to the lower end of the screw shaft portion, and having, the screw shaft portion is pivotally supported in a vertically movable state by a pivot boss fixed to the strain generating body. A washing machine.

6. In the washing machine according to any one of Claims 1 to 5, a water storage tank accommodated in the housing, a drum rotatably accommodated in the tank, a driving device for rotating the drum, a water supply device for supplying water to the tank, a drainage device for draining water from the tank, a control device for controlling the driving device, the water supply device, and the drainage device, further comprising, the control device executes a cloth quantity measuring process for measuring the weight of the laundry accommodated in the drum based on the measurement result of the load measuring device. A washing machine.

7. In the washing machine according to Claim 6, when an attachment device such as a dryer is placed on the washing machine, the control device further executes a resonance vibration suppression process for avoiding an increase in resonance vibration during dehydration processing based on the measurement result of the load measuring device. A washing machine.

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