JP2010207442A - Washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vibration and noise at the same time by preventing vibration of a washing machine body from being easily transmitted to a setting floor. <P>SOLUTION: Vibration of the washing machine body 30 and vibration of the setting floor 45 can be reduced from the start of dewatering process to the steady state by changing the spring constant suitable for reduction of the resonant vibration of the washing machine body 30 and the spring constant suitable for reduction of the steady vibration of the washing machine body 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a washing machine that performs laundry washing, rinsing, dehydration, and the like in a washing and dewatering tub that is rotatably provided in an outer tub elastically supported in a washing machine body.

  Conventionally, this type of washing machine has a large number of support legs mounted on a base fixed to the lower side of the washing machine main body so as to be movable in the vertical direction, and is attached to the lower end of the support leg to contact the bottom surface. And a spring attached between the base and the foot to give elasticity to the foot, and attached to the upper surface of the spring and the upper surface of the base to suppress resonance of the spring generated when the washing machine is driven. And a damping unit that reduces vibration (see, for example, Patent Document 1).

  In addition, there are some which support the washing machine body with an elastic support leg including a spring and a stopper that restricts expansion and contraction of the spring within a certain range (see, for example, Patent Document 2).

  FIG. 13 shows a configuration of a conventional washing machine support device described in Patent Document 1. As shown in FIG.

  As shown in FIG. 13, a support leg 12 that is inserted into the through hole 18 of the base 10 so as to be linearly movable in the vertical direction, and a foot that is attached to the lower end of the support leg 12 and contacts the bottom surface on which the washing machine is installed. 14, a spring 16 that elastically supports the foot, and a damping unit 60 that is attached to the upper surface of the base 10 and suppresses resonance of the spring 16 that occurs when the washing machine is driven to reduce vibration. ing. The damping unit 60 obtains a damping action by the friction member 70 rubbing against the inner peripheral surface of the housing 64. The support device configured as described above maintains the balance of the washing machine by the elasticity of the spring 16, further absorbs vibration generated from the washing machine, reduces transmission of the washing machine vibration to the bottom surface, and The vibration of the washing machine is reduced by suppressing the resonance of the spring 16 and exhibiting a damping function.

  FIG. 14 shows a configuration of a leg device of a conventional washing machine described in Patent Document 2. As shown in FIG.

As shown in FIG. 14, the elastic support leg 5 is a combination of a coil spring 20 and a stopper 21, and the coil spring 20 is accommodated inside a bottomed cylindrical cover 22 with the bottom 22 </ b> A facing up, One end is supported by the bottom portion 22 </ b> A and the other end is supported by the stopper 21 via a disk-shaped support member 23. The stopper 21 includes flanges 21 </ b> A and 21 </ b> B at both ends, and a shaft portion 21 </ b> C between the flanges 21 </ b> A and 21 </ b> B penetrates freely through the cap 24 attached to the opening of the cover 22 in the vertical direction. Then, the flange 21A located above the cap 24 is brought into contact with the support member 23, and the flange 21B located below the cap 24 is grounded to the floor surface 10 via a grounding portion 25 formed in a disk shape. The stopper 21 is made of rubber or resin. By supporting the washing machine body 1 with the elastic support legs 5, vibrations of the washing machine body 1 are absorbed.
JP 2005-152659 A JP-A-4-244195

  However, in the conventional configuration of Patent Document 1, since friction is used to obtain damping, damping force works in addition to resonance, and conversely, the vibration of the washing machine body is transmitted to the floor surface, and the floor is greatly vibrated. I had a problem at last.

  Further, in the conventional configuration of Patent Document 2, since the vibration at the time of resonance is regulated by the stopper without using attenuation, the impact of the stopper is transmitted to the floor surface, and the vibration and noise of the floor surface at the time of resonance are large. Had the problem of becoming.

  The present invention solves the above-described conventional problems, and by switching the spring constant of the second elastic body provided on the leg to a value optimal for reducing the resonance vibration or steady vibration of the washing machine body, The purpose is to realize low vibration, low noise and reduced vibration transmission to the installation floor.

  In order to solve the conventional problems, a washing machine of the present invention includes a washing machine body, an outer tub supported by a first elastic body provided at a bottom of the washing machine body, and the outer tub. A washing / dehydrating tub provided rotatably; a driving means for rotating the washing / dehydrating tub; a damper for suppressing vibration of the outer tub; and a leg for supporting the washing machine main body, At least one is provided with a second elastic body that absorbs vibration energy of the washing machine main body and spring constant switching means for switching a spring constant of the second elastic body.

  This makes it possible to switch between a spring constant suitable for reducing the resonance vibration of the washing machine main body and a spring constant suitable for reducing the steady vibration of the washing machine main body. Vibration transmission can be reduced.

  According to the washing machine of the present invention, the spring constant of the second elastic body provided on the leg supporting the washing machine main body is changed to the spring constant suitable for reducing the resonance vibration and the steady vibration of the washing machine main body. By providing the means, resonance vibration and stationary vibration of the washing machine main body, and further transmission of vibration to the installation floor can be reduced, and low vibration and low noise can be realized.

  The first invention includes a washing machine body, an outer tub supported by a first elastic body provided at the bottom of the washing machine body, and a washing and dewatering tub provided rotatably in the outer tub. , A driving means for rotating the washing and dewatering tub, a damper for suppressing vibration of the outer tub, and a leg for supporting the washing machine body, wherein at least one of the legs is a vibration of the washing machine body. By adopting a washing machine provided with a second elastic body that absorbs energy and a spring constant switching means for switching the spring constant of the second elastic body, a spring constant suitable for reducing the resonance vibration of the washing machine body, The spring constant suitable for reducing the steady vibration of the washing machine body can be switched, and the vibration of the washing machine body and the transmission of vibration to the installation floor can be reduced from the start of dehydration to the steady state.

  According to the second invention, in particular, the spring constant switching means of the first invention is a washing machine configured to switch the spring constant of the second elastic body according to the number of rotations of the washing and dewatering tub. The optimum spring constant of the second elastic body can be selected by discriminating the resonance vibration and steady vibration of the washing machine main body according to the rotation speed of the washing and dewatering tub. Vibration transmission to the floor can be reduced. Further, since it is not necessary to newly provide a rotation sensor by using the rotation signal of the driving means, it can be configured at a low cost.

  In particular, the third invention includes a first vibration sensor fixed to the outer tub, and the spring constant switching means of the first invention determines the spring constant of the second elastic body according to the signal of the first vibration sensor. By adopting the washing machine configured to switch, the spring constant of the second elastic body suitable for the vibration of the washing machine main body synchronized with the magnitude of the vibration of the outer tub can be selected, and the vibration of the washing machine main body can be selected. And vibration transmission to the installation floor can be reduced efficiently.

  The fourth aspect of the invention is particularly provided with a second vibration sensor fixed to the washing machine body, and the spring constant switching means of the first invention is based on the signal of the second vibration sensor and the spring constant of the second elastic body. By switching the washing machine to the optimum spring constant by accurately discriminating between the resonance vibration of the washing machine main body and the steady vibration, the washing machine main body vibration from the start of dehydration to the steady state can be obtained. And vibration transmission to the installation floor can be effectively reduced.

  The fifth invention particularly includes a third vibration sensor fixed to the leg, and the spring constant switching means of the first invention switches the spring constant of the second elastic body according to the signal of the third vibration sensor. By configuring the washing machine as described above, the resonance vibration of the washing machine main body and the steady vibration can be discriminated and switched to the optimum spring constant in a short time. Vibration transmission to the installation floor can be further effectively reduced.

  The sixth aspect of the invention is particularly a washing machine comprising a load sensor provided on a leg, wherein the spring constant switching means of the first invention is configured to switch the spring constant of the second elastic body according to the signal of the load sensor. By minimizing vibration transmission to the floor of the washing machine main body, the vibration transmission to the floor of the washing machine main body can be further effectively reduced from the start of dehydration to the steady state, and the resulting noise can be reduced. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a sectional view of a washing machine according to the first embodiment of the present invention. FIG. 2 shows a sectional view of the legs of the washing machine.

  1 and 2, the outer tub 33 accommodated in the washing machine main body 30 is elasticized by two first elastic bodies 31 and two dampers 32 provided on the bottom 30a of the washing machine main body. It is supported. The washing / dehydrating tub 34 has a large number of through holes 34 a in the peripheral wall, and is rotatably disposed in the outer tub 33. The motor (driving means) 35 is composed of a brushless DC motor and is controlled by an inverter so that the rotational speed can be freely changed. Then, the washing / dehydrating tub 34 is directly rotated. The water supply means 36 supplies water into the outer tub 33. The water level detection means 37 detects the washing water level in the outer basket 33. The drainage means 38 drains the washing water in the outer tub 33.

  The control device 39 is provided at the lower front portion of the washing machine main body 30, and based on the setting contents input by the operation display means 40 provided at the upper front portion of the washing machine main body 30, each of washing, rinsing, and dehydration is performed. The process is sequentially controlled, and the motor 35, the water supply means 36, the drainage means 38, and the like are sequentially controlled via a power switching means (not shown).

  The damper 32 is a viscous damper that uses oil as a working fluid, and reduces the resonance vibration amplitude of the outer tub 33 at the time of dehydration activation. A damper is provided between the bottom 30 a of the washing machine body and the bottom 33 a of the outer tub 33. The first elastic body 31 and the first elastic body 31 are fixed in a concentric state. The tension spring 41 maintains the posture of the outer tub 33, and is provided between the top plate 30 b and the outer tub 33.

The leg 42 is arrange | positioned at the right front part of the bottom part 30a of the washing machine main body 30, and is comprised by the bottomed cylindrical leg main body 42a, the support body 42b, the 2nd elastic body 42c, and the bag body 42d. The second elastic body 42c is inserted into the leg main body 42a, and then the support body 42b is attached. The bag body 42d is disposed outside the second elastic body 42c. A screw part 42e for attaching to the bottom part 30a of the washing machine main body is provided at the upper part of the leg main body 42a, and a pipe line 42f leading to the inside of the bag body 42d is provided at the center of the screw part 42e. The screw part 42e is inserted into the bottom part 30a of the washing machine body and fixed with the nut 43.

The spring constant switching means 44 is attached to the outlet of the pipeline 42f, and includes a main body 44a, a switching valve 44b, a solenoid 44c, and a support spring 44d. The switching valve 44b is provided with a small valve hole 44e and a large valve hole 44f. The opening area of the small valve hole 44e is set to 0.8 mm ² , and the large valve hole 44f is set to 3 mm ² . By moving the switching valve 44b by the solenoid 44c so that either the small valve hole 44e or the large valve hole 44f faces the pipe line 42f, the size of the opening area of the outlet of the pipe line 42f can be switched.

  A buffer rubber 42g is attached to the grounding portion of the support 42b to absorb vibration of the washing machine body 30 and protect the installation floor.

  About the washing machine comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, after putting clothes and detergent into the washing and dewatering tub 34, the operation display means 40 is operated to start operation. As a result, the water supply means 36 operates, the washing water is supplied into the outer tub 33, and the washing / dehydration tub 34 also starts rotating. The washing water supplied into the outer tub 33 is supplied into the washing and dewatering tub 34 through the through hole 34a. When the water level detection means 37 detects that a specified amount of washing water has been supplied, the water supply means 36 stops water supply. By the rotation of the washing and dewatering tub 34, the detergent is dissolved in the washing water and becomes a washing liquid and penetrates into the clothes. The washing and dewatering tub 34 rotates at a low speed of about 45 r / min, and performs washing for a predetermined time of lifting and dropping clothes.

  After the washing is finished, the drainage means 38 is operated, and the washing water in which the dirt is dissolved is drained out of the outer tub 33. After the drainage is completed, the process proceeds to a dehydration process in which the washing and dewatering tub 34 is rotated at high speed.

  In the dehydration process, at the time of dehydration activation in which the rotation of the washing / dehydrating tub 34 is gradually increased, the outer tub 33 is moved depending on the state of the laundry while the rotation speed of the washing / dehydrating tub 34 is 250 to 300 r / min. It may move up and down greatly while shaking back and forth and left and right. At this time, the vertical movement of the outer tub 33 is buffered by the elastic body 31 and attenuated by the damper 32. Further, vibration transmission of the outer tub 33 is also reduced. However, it is transmitted to the top plate 30b and the bottom 30a of the washing machine main body 30 via the elastic body 31, the damper 32, and the tension spring 41, and the washing machine main body 30 is vibrated. This vibration is transmitted to the installation floor 45 through the legs 42, and in the case of a soft floor, the floor vibrates greatly. At this time, the spring constant switching means 44 is set to “strong”. This “strong” state is as follows.

  That is, power is not supplied to the solenoid 44c, the switching valve 44b is pushed by the support spring 44d, and a small valve hole 44e is disposed at the outlet of the conduit 42f. The second elastic body 42c expands and contracts to absorb the vibration of the washing machine main body 30, and the bag body 42d expands and contracts accordingly. However, the movement of air due to the expansion and contraction is suppressed because the outlet of the pipeline 42f is narrow. The air spring property of the bag body 42d becomes hard, and the damping force generated when the air in the bag body 42d passes through the small valve hole 44e becomes strong, and the vibration of the washing machine body 30 is reduced.

  On the other hand, when the rotation speed of the washing / dehydrating tub 34 increases and reaches around 720 r / min (12 Hz) before the normal rotation (for example, 1000 r / min), the washing machine main body 30 and the second elastic body 42 c of the leg 42 are provided. At this time, the spring constant switching means 44 is set to “weak”. This “weak” state is as follows.

That is, if power is supplied to the solenoid 44c to pull the switching valve 44b and the large valve hole 44f is installed at the outlet of the conduit 42f, the air in the bag body 42d is easily moved.
The air spring property of d becomes weak, the spring constant of the second elastic body 42c becomes dominant, and the resonance frequency composed of the washing machine body 30 and the second elastic body 42c of the leg 42 is 14 Hz (840 r / min). ) What was before and after is greatly moved to around 10 Hz (600 r / min). Therefore, even though the number of rotations of the washing / dehydrating tub 34 is around 720 r / min (12 Hz), the resonance frequency composed of the washing machine body 30 and the second elastic body 42 c of the legs 42 is 10 Hz (600 r / min). Since the rotation speed of the washing / dehydrating tub 34 passes through the resonance frequency instantaneously, the vibration of the washing machine body 30 and the vibration of the installation floor 45 reach steady rotation without increasing.

  As described above, in the first embodiment, the spring constant suitable for reducing the resonance vibration of the washing machine body 30 and the spring constant suitable for reducing the steady vibration of the washing machine body 30 can be switched. The vibration of the washing machine main body 30 and the vibration of the installation floor 45 can be reduced until the rotation.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of a washing machine according to the second embodiment of the present invention. FIG. 4 is a graph showing the rotational speed of the washing and dewatering tub and the vibration amplitude of each part of the washing machine. In addition, about the structure same as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  3 and 4, a signal line 46 for transmitting a rotation signal of a rotation sensor (not shown) provided in the driving unit 35 to the control device 39 is provided. The control device 39 controls the drive means 35 so that the rotation speed becomes a specified rotation speed by a signal from the rotation sensor.

  The control device 39 also controls the spring constant switching means 44 in accordance with the rotation sensor signal. At the rotation speed R0, the outer tub 33 may move up and down greatly while shaking back and forth and left and right depending on the biased state of the laundry. At this time, the vertical movement of the outer tub 33 is buffered by the elastic body 31 and attenuated by the damper 32. Further, vibration transmission of the outer tub 33 is also reduced. However, it is transmitted to the top plate 30b and the bottom 30a of the washing machine main body 30 via the elastic body 31, the damper 32, and the tension spring 41, and the washing machine main body 30 is vibrated. This vibration is transmitted to the installation floor 45 through the legs 42, and in the case of a soft floor, the floor vibrates greatly. At the rotational speed R0, the spring constant switching means 44 is set to “strong”. This “strong” state is as follows.

  That is, power is not supplied to the solenoid 44c, the switching valve 44b is pushed by the support spring 44d, and a small valve hole 44e is disposed at the outlet of the conduit 42f. The second elastic body 42c expands and contracts to absorb the vibration of the washing machine main body 30, and the bag body 42d expands and contracts accordingly. However, the movement of air due to the expansion and contraction is suppressed because the outlet of the pipeline 42f is narrow. The air spring property of the bag body 42d becomes hard, and the damping force generated when the air in the bag body 42d passes through the small valve hole 44e becomes strong, and the vibration of the washing machine body 30 is reduced.

  When the number of rotations of the washing and dewatering tub 34 increases and reaches the number of rotations R4 before the regular rotation (the number of rotations R3), resonance vibration composed of the washing machine body 30 and the second elastic body 42c of the legs 42 starts. At this time, the spring constant switching means 44 is set to “weak”. This “weak” state is as follows.

That is, if power is supplied to the solenoid 44c to pull the switching valve 44b and the large valve hole 44f is installed at the outlet of the conduit 42f, the air in the bag body 42d is easily moved, and the air spring property of the bag body 42d is weak. Thus, the spring constant of the second elastic body 42c becomes dominant, and the resonance frequency composed of the washing machine main body 30 and the second elastic body 42c of the leg 42 moves greatly from the rotational speed R2 to the rotational speed R1. Accordingly, since the resonance frequency is the rotation number R1 even though the rotation speed of the washing and dewatering tub 34 is the rotation number R4, it means that the resonance frequency has been passed instantaneously, and the vibration and installation of the washing machine main body 30 are performed. The vibration of the floor 45 reaches the rotational speed R3 of steady rotation without increasing.

  Therefore, as shown by “vibration amplitude of the washing machine main body 30” in FIG. 4, originally, the mountain-shaped vibration amplitude as indicated by the broken line b at the rotational speed R0 and the broken line d at the rotational speed R1. A mountain-shaped vibration amplitude as indicated by a broken line c appears at a large mountain-shaped vibration amplitude and a rotational speed R2, but in the second embodiment, as shown by a solid line a, the shape is almost flat. The vibration amplitude can be realized.

  As described above, in the second embodiment, the optimum spring constant of the second elastic body 42c is selected by discriminating the resonance vibration and the steady vibration of the washing machine body 30 from the number of rotations of the washing and dewatering tub 34. The vibration of the washing machine body 30 and the vibration of the installation floor 45 can be reduced from the start of dehydration to the steady state.

(Embodiment 3)
FIG. 5 shows a sectional view of a washing machine according to the third embodiment of the present invention. FIG. 6 is a graph showing the vibration amplitude of the outer tub of the washing machine and the vibration amplitude of the washing machine body. In addition, about the structure same as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  5 and 6, the first vibration sensor 47 is provided in the upper front portion of the outer tub 33. The first vibration sensor 47 is composed of a piezoelectric element. The output signal of the first vibration sensor 47 is transmitted to the control device 39, and the control device 39 calculates the inclination ΔD1 = | D0−D1 | of the vibration amplitude of the outer tub 33.

  In the dehydration process, when the dehydration is started, the outer tub 33 may move up and down greatly while swinging back and forth and left and right depending on the biased state of the laundry. At this time, ΔD1 becomes a value larger than a predetermined value. At this time, the vertical movement of the outer tub 33 is buffered by the elastic body 31 and attenuated by the damper 32. Further, vibration transmission of the outer tub 33 is also reduced. However, it is transmitted to the top plate 30b and the bottom 30a of the washing machine main body 30 via the elastic body 31, the damper 32, and the tension spring 41, and the washing machine main body 30 is vibrated. This vibration is transmitted to the installation floor 45 through the legs 42, and in the case of a soft floor, the floor vibrates greatly. At this time, the spring constant switching means 44 is set to “strong”. This “strong” state is as follows.

  That is, power is not supplied to the solenoid 44c, the switching valve 44b is pushed by the support spring 44d, and a small valve hole 44e is disposed at the outlet of the conduit 42f. The second elastic body 42c expands and contracts to absorb the vibration of the washing machine main body 30, and the bag body 42d expands and contracts accordingly. However, the movement of air due to the expansion and contraction is suppressed because the outlet of the pipeline 42f is narrow. The air spring property of the bag body 42d becomes hard, and the damping force generated when the air in the bag body 42d passes through the small valve hole 44e becomes strong, and the vibration of the washing machine body 30 is reduced.

  Thereafter, when ΔD1 becomes smaller than the specified value, the control device 39 sets the spring constant switching means 44 to “weak”. This “weak” state is as follows.

That is, power is supplied to the solenoid 44c to pull the switching valve 44b, and a large valve hole 44f is installed at the outlet of the conduit 42f to facilitate movement of the air in the bag body 42d. And the resonance frequency is lowered so that the spring constant of the second elastic body 42c becomes dominant. Therefore, although the washing / dehydrating tub 34 has a high rotation speed, the resonance frequency is at a position lower than that, and therefore the resonance frequency has been instantaneously passed. And the vibration of the installation floor 45 reach steady rotation without increasing.

  Therefore, as shown by “vibration amplitude of washing machine main body 30” in FIG. 6, when ΔD1 is larger than a predetermined value, a mountain-shaped vibration amplitude as indicated by a broken line f, ΔD1 is a predetermined value. If it is smaller, a chevron-shaped vibration amplitude as indicated by a broken line h or a broken line g appears. In the third embodiment, a substantially flat vibration amplitude having almost no chevron is realized as shown by a solid line e. It can be done.

  As described above, in the third embodiment, the spring constant of the second elastic body 42c suitable for the vibration of the washing machine body 30 synchronized with the magnitude of the vibration of the outer tub 33 can be selected, and the washing machine The vibration of the main body 30 and the vibration of the installation floor 45 can be efficiently reduced.

(Embodiment 4)
FIG. 7 shows a sectional view of a washing machine according to the fourth embodiment of the present invention. FIG. 8 is a graph showing the vibration amplitude of the washing machine main body of the washing machine. In addition, about the structure same as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  7 and 8, the second vibration sensor 48 is provided on the front surface 30c of the washing machine body. The second vibration sensor 48 is composed of a piezoelectric element. The output signal of the second vibration sensor 48 is transmitted to the control device 39, and the control device 39 calculates the inclination ΔD3 = | D3-D2 | of the vibration amplitude of the front surface 30c of the washing machine body.

  In the dehydration process, when the dehydration is started, the outer tub 33 may move greatly up and down while swinging back and forth and left and right due to the biased state of the laundry. At this time, the vertical movement of the outer tub 33 is buffered by the elastic body 31 and attenuated by the damper 32. Further, vibration transmission of the outer tub 33 is also reduced. However, it is transmitted to the top plate 30b and the bottom 30a of the washing machine main body 30 via the elastic body 31, the damper 32, and the tension spring 41, and the washing machine main body 30 is vibrated. This vibration is transmitted to the installation floor 45 through the legs 42, and in the case of a soft floor, the floor vibrates greatly. At the start of dehydration, the spring constant switching means 44 is set to “strong”. This “strong” state is as follows.

  That is, power is not supplied to the solenoid 44c, the switching valve 44b is pushed by the support spring 44d, and a small valve hole 44e is disposed at the outlet of the conduit 42f. The second elastic body 42c expands and contracts to absorb the vibration of the washing machine main body 30, and the bag body 42d expands and contracts accordingly. However, the movement of air due to the expansion and contraction is suppressed because the outlet of the pipeline 42f is narrow. The air spring property of the bag body 42d becomes hard, and the damping force generated when the air in the bag body 42d passes through the small valve hole 44e becomes strong, and the vibration of the washing machine body 30 is reduced.

  Thereafter, when the rotational speed of the washing and dewatering tub 34 increases and the resonance of the washing machine body 30 approaches and ΔD3 becomes larger than the specified value, the control device 39 sets the spring constant switching means 44 to “weak”. . This “weak” state is as follows.

  That is, power is supplied to the solenoid 44c to pull the switching valve 44b, and a large valve hole 44f is installed at the outlet of the conduit 42f to facilitate movement of the air in the bag body 42d. And the resonance frequency is lowered so that the spring constant of the second elastic body 42c becomes dominant. Therefore, although the washing / dehydrating tub 34 has a high rotation speed, the resonance frequency is at a position lower than that, and therefore the resonance frequency has been instantaneously passed. And the vibration of the installation floor 45 reach steady rotation without increasing.

  Therefore, as shown by “vibration amplitude of the washing machine body 30” in FIG. 8, when the dewatering start-up, the mountain-shaped vibration amplitude as shown by the broken line j, ΔD3 is larger than a predetermined value. A chevron-shaped vibration amplitude as shown by a broken line k or a broken line m appears. In the fourth embodiment, as shown by a solid line i, a substantially flat vibration amplitude having almost no chevron can be realized. .

  Thereby, the resonance vibration and the steady vibration of the washing machine body 30 can be accurately discriminated and switched to the optimum spring constant, so that the vibration of the washing machine body 30 and the vibration of the installation floor 45 are effective from the start of dehydration to the steady state. Can be reduced.

(Embodiment 5)
FIG. 9 shows a cross-sectional view of the legs of the washing machine in the fifth embodiment of the present invention. FIG. 10 is a graph showing the vibration amplitude of the legs of the washing machine. In addition, about the structure same as Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  9 and 10, the third vibration sensor 49 is provided above the spring constant switching means 44. The third vibration sensor 49 is composed of a piezoelectric element. The output signal of the third vibration sensor 49 is transmitted to the control device 39, and the control device 39 calculates the inclination ΔD5 = | D5-D4 | of the vibration amplitude at the upper part of the spring constant switching means 44.

  In the dehydration process, when the dehydration is started, the outer tub 33 may move greatly up and down while swinging back and forth and left and right due to the biased state of the laundry. At this time, the vertical movement of the outer tub 33 is buffered by the elastic body 31 and attenuated by the damper 32. Further, vibration transmission of the outer tub 33 is also reduced. However, it is transmitted to the top plate 30b and the bottom 30a of the washing machine main body 30 via the elastic body 31, the damper 32, and the tension spring 41, and the washing machine main body 30 is vibrated. This vibration is transmitted to the installation floor 45 through the legs 42, and in the case of a soft floor, the floor vibrates greatly. At the start of dehydration, the spring constant switching means 44 is set to “strong”. This “strong” state is as follows.

  That is, power is not supplied to the solenoid 44c, the switching valve 44b is pushed by the support spring 44d, and a small valve hole 44e is disposed at the outlet of the conduit 42f. The second elastic body 42c expands and contracts to absorb the vibration of the washing machine main body 30, and the bag body 42d expands and contracts accordingly. However, the movement of air due to the expansion and contraction is suppressed because the outlet of the pipeline 42f is narrow. The air spring property of the bag body 42d becomes hard, and the damping force generated when the air in the bag body 42d passes through the small valve hole 44e becomes strong, and the vibration of the washing machine body 30 is reduced.

  Thereafter, when the rotational speed of the washing and dewatering tub 34 increases and the resonance of the washing machine body 30 approaches and ΔD5 becomes larger than the specified value, the control device 39 sets the spring constant switching means 44 to “weak”. . This “weak” state is as follows.

  That is, power is supplied to the solenoid 44c to pull the switching valve 44b, and a large valve hole 44f is installed at the outlet of the conduit 42f to facilitate movement of the air in the bag body 42d. And the resonance frequency is lowered so that the spring constant of the second elastic body 42c becomes dominant. Therefore, although the washing / dehydrating tub 34 has a high rotation speed, the resonance frequency is at a position lower than that, and therefore the resonance frequency has been instantaneously passed. And the vibration of the installation floor 45 reach steady rotation without increasing.

Therefore, as shown by “vibration amplitude of leg 42” in FIG. 10, originally, when dehydration is started, a mountain-shaped vibration amplitude as shown by broken line p, and when ΔD5 is larger than a predetermined value, broken line q Alternatively, a chevron-shaped vibration amplitude as indicated by a broken line r appears. In the fourth embodiment, a substantially flat vibration amplitude having almost no chevron can be realized as shown by a solid line n.

  In this way, by switching the spring constant of the second elastic body 42c by the signal of the third vibration sensor 49 provided in the spring constant switching means 44, the resonance vibration and the steady vibration of the washing machine body 30 can be achieved in a short time. Therefore, the vibration of the washing machine main body 30 and the vibration of the installation floor 45 can be further effectively reduced from the start of dehydration to the steady state.

(Embodiment 6)
FIG. 11 shows a cross-sectional view of the legs of the washing machine in the sixth embodiment of the present invention. FIG. 12 is a graph showing the load applied to the legs of the washing machine.

  11 and 12, the load sensor 50 is provided between the leg main body 42a and the bottom 30a of the washing machine main body. The load sensor 50 is composed of a piezoelectric element. The output signal of the load sensor 48 is transmitted to the control device 39, and the control device 39 calculates the load gradient ΔF = | F1-F0 |.

  In the dehydration process, when the dehydration is started, the outer tub 33 may move greatly up and down while swinging back and forth and left and right due to the biased state of the laundry. At this time, the vertical movement of the outer tub 33 is buffered by the elastic body 31 and attenuated by the damper 32. Further, vibration transmission of the outer tub 33 is also reduced. However, it is transmitted to the top plate 30b and the bottom 30a of the washing machine main body 30 via the elastic body 31, the damper 32, and the tension spring 41, and the washing machine main body 30 is vibrated. This vibration is transmitted to the installation floor 45 through the legs 42, and in the case of a soft floor, the floor vibrates greatly. At the start of dehydration, the spring constant switching means 44 is set to “strong”. This “strong” state is as follows.

  That is, power is not supplied to the solenoid 44c, the switching valve 44b is pushed by the support spring 44d, and a small valve hole 44e is disposed at the outlet of the conduit 42f. The second elastic body 42c expands and contracts to absorb the vibration of the washing machine main body 30, and the bag body 42d expands and contracts accordingly. However, the movement of air due to the expansion and contraction is suppressed because the outlet of the pipeline 42f is narrow. The air spring property of the bag body 42d becomes hard, and the damping force generated when the air in the bag body 42d passes through the small valve hole 44e becomes strong, and the vibration of the washing machine body 30 is reduced.

  Thereafter, when the rotational speed of the washing and dewatering tub 34 increases and the resonance of the washing machine body 30 approaches and ΔF becomes larger than a specified value, the control device 39 sets the spring constant switching means 44 to “weak”. . This “weak” state is as follows.

  That is, power is supplied to the solenoid 44c to pull the switching valve 44b, and a large valve hole 44f is installed at the outlet of the conduit 42f to facilitate movement of the air in the bag body 42d. And the resonance frequency is lowered so that the spring constant of the second elastic body 42c becomes dominant. Therefore, the rotation of the washing and dewatering tub 34 instantaneously passes the resonance frequency, and the vibration of the washing machine main body 30 and the vibration of the installation floor 45 reach a steady rotation without increasing.

Accordingly, as shown by “load amplitude of the leg 42” in FIG. 12, originally, when the dehydration is started, a mountain-shaped vibration amplitude as indicated by a broken line t, and when ΔF is larger than a predetermined value, a broken line u Alternatively, a mountain-shaped vibration amplitude as indicated by a broken line v appears. In the sixth embodiment, a substantially flat vibration amplitude having almost no mountain shape can be realized as shown by the solid line s.

  Thus, by switching the spring constant of the second elastic body 42c according to the signal of the load sensor 48 provided on the leg 42, the vibration to the installation floor 45 of the washing machine body 30 can be minimized, so that the dehydration start can be started. The vibration of the washing machine main body 30 and the vibration of the installation floor can be further effectively reduced to the steady state, and noise resulting therefrom can be reduced.

  In the above embodiment, the rotation axis of the washing / dehydrating tub 34 is horizontal, but the same effect can be obtained even when the washing / dehydrating tub 34 is inclined forward and high.

  As described above, the washing machine according to the present invention can reduce the vibration of the washing machine body and the installation floor by providing the spring constant switching means for the legs that support the washing machine body. It can also be applied to vibration isolation.

Sectional drawing of the washing machine in Embodiment 1 of this invention Cross section of legs of the washing machine Sectional drawing of the washing machine in Embodiment 2 of this invention A graph showing the number of rotations of the washing and dewatering tank and the vibration amplitude of each part of the washing machine Sectional drawing of the washing machine in Embodiment 3 of this invention Graph showing the vibration amplitude of the outer tub of the washing machine and the vibration amplitude of the washing machine body Sectional drawing of the washing machine in Embodiment 4 of this invention Graph showing the vibration amplitude of the washing machine body of the washing machine Sectional drawing of the leg of the washing machine in Embodiment 5 of this invention Graph showing the vibration amplitude of the legs of the washing machine Sectional drawing of the leg of the washing machine in Embodiment 6 of this invention Graph showing the load on the legs of the washing machine Sectional view of a leg of a conventional washing machine Sectional view of a leg of a conventional washing machine

DESCRIPTION OF SYMBOLS 30 Washing machine main body 30a Bottom part of washing machine main body 31 1st elastic body 32 Damper 33 Outer tub 34 Washing and dewatering tub 35 Drive means 42 Leg 42c 2nd elastic body 44 Spring constant switching means 47 Vibration sensor 48 Load sensor

Claims (6)

A washing machine body, an outer tub supported by a first elastic body provided at the bottom of the washing machine body, a washing / dehydration tub provided rotatably in the outer tub, and the washing / dehydration tub Driving means for rotating the outer tub, a damper for suppressing vibration of the outer tub, and a leg for supporting the washing machine body, wherein at least one of the legs absorbs vibration energy of the washing machine body. And a spring constant switching means for switching the spring constant of the second elastic body. The washing machine according to claim 1, wherein the spring constant switching means is configured to switch the spring constant of the second elastic body according to the number of rotations of the washing and dewatering tub. The washing machine according to claim 1, further comprising a first vibration sensor fixed to the outer tub, wherein the spring constant switching means switches the spring constant of the second elastic body according to a signal from the first vibration sensor. 2. The washing machine according to claim 1, further comprising a second vibration sensor fixed to the washing machine body, wherein the spring constant switching means switches the spring constant of the second elastic body according to a signal from the second vibration sensor. . The washing machine according to claim 1, further comprising a third vibration sensor fixed to the leg, wherein the spring constant switching means switches the spring constant of the second elastic body according to a signal from the third vibration sensor. The washing machine according to claim 1, further comprising a load sensor provided on a leg, wherein the spring constant switching means switches the spring constant of the second elastic body according to a signal of the load sensor.