JP2014183889A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-proof device that can stably suppress vibration irrespective of a weight of laundry.SOLUTION: The washing machine includes: a washing and dewatering tub 3 for housing laundry; a water tub 2 containing the washing and dewatering tub 3; and a vibration-proof device supporting the water tub 2 on an outer frame 1. The vibration-proof device has a suspension 9 comprising a compression coil spring 16. The compression coil spring 16 has a long pitch part 18 and short pitch parts 17 on both sides of the long pitch part 18. When laundry is not in the washing and dewatering tub 3, a spring constant is denoted by k1 and a weight supported by the suspension 9 at the time is denoted by m1. When laundry is in the washing and dewatering tub 3, a spring constant is denoted by k2 and a weight supported by the suspension 9 at the time is denoted by m2. Then, the compression coil spring 16 is set to satisfy k2/k1<m2/m1. Thus, it is possible to suppress vibration due to stable amplitude in resonance of a vibration system, and possible to suppress an abnormal sound and an abnormal vibration in a dewatering operation irrespective of the weight of laundry.

Description

  The present invention relates to a washing machine having a water tank that is supported in a vibration-proof manner inside an outer frame.

  Conventionally, this type of washing machine has been proposed to reduce the vibration of a water tank that is supported by vibration isolation inside the outer frame (see, for example, Patent Document 1).

  FIG. 3 is a longitudinal sectional view of a conventional washing machine, and FIG. 4 is a sectional view of a main part of a vibration isolator of the washing machine.

  3 and 4, a power transmission mechanism 21 is fixed to the bottom of the water tank 20 that is elastically suspended and supported from above the outer frame 28 via a suspension 29. The power transmission mechanism 21 is connected to a motor 22 provided on the outer bottom of the water tank by a belt, and the stirring blade shaft 23 inside the power transmission mechanism 21 is rotatably provided on the inner bottom of the washing / dehydrating tank 26. A wing 24 is fixed, and a washing / dehydrating tub 26 is fastened to the outer shaft 25 in the water tub 20. In addition, a fluid balancer 27 for reducing vibration is provided in the upper part of the washing and dewatering tank 26.

  The suspension 29 includes a suspension rod 30, a slider 31, a vibration isolation spring 32, and a spring support plate 33. A hemispherical suspension rod support portion 34 is provided on the outer frame 28. In addition, on the outer periphery of the suspension rod support portion 34, a sliding restriction wall 36 that restricts the sliding range of the suspension rod support base 35 that is placed on the suspension rod support portion 34 and slides on a spherical surface is provided.

  With the above configuration, when the dehydration process is started after the washing process is finished, the water tank 20 tends to vibrate greatly due to the imbalanced state of the clothes that have been offset in the washing and dehydrating tank 26 during the washing process. The movement of the suspension rod support base 35 is restricted by the sliding restriction wall 36 provided on the outer periphery of the suspension rod support portion 34. Thereby, the lateral vibration of the water tank 20 is reduced.

Japanese Patent Laid-Open No. 5-42289

  However, in the conventional configuration, when the washing machine is increased in size and the capacity of the laundry is increased, the dehydration rotational speed reaches the resonance point of the vibration system including the water tank supported by vibration isolation from the outer frame. In this case, the vibration system greatly vibrates up and down rather than rolls, and when the bottom dead center is reached, a phenomenon that the spring of the vibration isolator is in close contact is likely to occur. In such a case, there is a problem that a loud collision sound is generated when the spring is in close contact, and the entire product is moved by the impact force.

  The present invention solves the above-described conventional problems, and provides a washing machine having a vibration isolator capable of stably suppressing vibration at the time of resonance of a vibration system regardless of whether the laundry is light or heavy. The purpose is to do.

In order to solve the conventional problems, a washing machine according to the present invention includes a washing / dehydrating tub for storing laundry, a water tub containing the washing / dehydrating tub, and a vibration isolator for supporting the water tub on an outer frame. And
The vibration isolator has a suspension including a compression coil spring, the compression coil spring has a short pitch portion on both sides of a long pitch portion, and the compression coil spring contains laundry in the washing and dewatering tub. K1 is the spring constant when the suspension is not present, m1 is the weight supported by the suspension at that time, and k2 is the spring constant when the laundry is contained in the washing and dewatering tub. When the weight is m2, k2 / k1 <m2 / m1 is set.

  This makes it possible to stabilize the vibration amplitude of the vibration system supported by the anti-vibration device from the outer frame, regardless of whether the laundry is light or heavy. Vibration can be suppressed.

  In the washing machine of the present invention, the amplitude at the time of resonance is stably suppressed regardless of the weight of the laundry, and abnormal noise and abnormal vibration during dehydration operation can be suppressed.

The longitudinal cross-sectional view of the washing machine in embodiment of this invention Cross section of the main part of the suspension of the washing machine Vertical section of a conventional washing machine Cross section of the main part of the vibration isolator of the washing machine

  A first invention includes a washing / dehydrating tub for storing laundry, a water tub containing the washing / dehydrating tub, and a vibration isolating device for supporting the water tub on an outer frame, wherein the vibration isolating device is a compression coil. A suspension including a spring, the compression coil spring has a short pitch portion on both sides of a long pitch portion, and the compression coil spring has a spring constant k1 when there is no laundry in the washing and dewatering tub. The weight supported by the suspension at that time is m1, the spring constant when the laundry is in the washing and dewatering tub is k2, and the weight supported by the suspension at that time is m2. Occasionally, k2 / k1 <m2 / m1 is set so that the laundry put in the washing / dehydrating tub is supported by a vibration isolator from the outer frame regardless of whether the laundry is light or heavy. The amplitude at resonance of the vibration system Is suppressed by a constant, it is possible to suppress the abnormal sound or abnormal vibration during the dewatering operation.

  Hereinafter, embodiments of the invention will be described with reference to the drawings. Further, the present invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a washing machine according to an embodiment of the present invention.

  In FIG. 1, a washing / dehydrating tub 3 having a large number of small holes 6 for draining water on a side wall is rotatable inside a water tub 2 supported by a support rod 8 and a vibration isolator from a corner of the outer frame. The washing and dewatering tub 3 is provided with a pulsator 4 for stirring clothes at the bottom of the center and a fluid balancer 5 for reducing dehydration vibration at the top.

  The motor 7 is provided on the outer bottom of the water tub 2 and rotates the pulsator 4 during the washing process and the rinsing process, and the washing and dehydrating tank 3 during the dehydration process.

  Moreover, the upper frame 10 provided in the upper part of the outer frame 1 is provided with a lid 12 that covers the laundry input port 11 formed in a substantially central part so as to be freely opened and closed. The vibration isolator is exemplified as a configuration including the support rod 8 and the suspension 9.

  FIG. 2 shows a cross-sectional view of the main part of the suspension of the washing machine in the embodiment of the present invention.

  In FIG. 2, the suspension 9 has a cap 13 at the lower end of the support bar 8 penetrating through the support bar 8 at the center, and a slider 14 that frictionally contacts the cap 13 at the inner periphery to generate a damper force. Provided. Further, an air hole 15 is provided in the upper part of the slider 14, and a viscous damping effect is given by the air moving out or entering the air hole 15 by the vertical movement of the slider 14.

  The suspension 9 includes an unequal pitch compression coil spring 16 disposed between the upper surface of the cap 13 and the inner surface of the slider 14, and is formed at the center portion compared to the short pitch portions 17 formed at both ends. The range of about 1/2 of the total number of turns is formed as a pitch portion 18 having a long pitch. Thereby, when the laundry put into the washing and dewatering tub 3 is small, only the short pitch portion 17 having a small spring constant is compressed, and when the laundry is large, the spring constant is compressed together with the compression of the short pitch portion 17. The long pitch portion 18 having a large length is compressed (the spring constant is inversely proportional to the effective number of turns). Further, the free length of the compression coil spring 16 is set so that the cap 13 is placed inside the slider 14 from below so that an appropriate damping force can be obtained when the washing and dewatering tub 3 is not loaded with water or laundry. It is set to a length that is slightly intruding.

  The operation and effect of the washing machine configured as described above will be described below.

  In the dehydration process, when the vertical vibration of the entire vibration system including the water tank 2 supported by vibration isolation from the outer frame 1 is considered as a forced vibration with damping, the dehydration rotation speed reaches the resonance point of the vibration system. Considering that the attenuation is somewhat small, the maximum amplitude A is approximately represented by A = (f / k) × εc / ε / 2. At this time, f is a force applied to the suspension 9 including the compression coil spring 16, k is a spring constant of the compression coil spring 16, εc is a critical damping constant, and ε is a damping constant.

Here, the spring constant when the laundry is not contained is k1, the weight supported by the suspension 9 at that time is m1, the spring constant when the laundry is contained is k2, and the suspension 9 is supported at that time. It is assumed that the weight of the vibration system is m2, the unbalance amount of the vibration system is the same, and the force f applied to the suspension 9 is proportional to the centrifugal force generated by the unbalance at the resonance rotational speed. When the maximum amplitude A1 and the maximum amplitude A2 at the resonance when the laundry is contained are calculated (the calculation is omitted in the middle), A2 = ((k2 / k1) / (m2 / m1)) ^1/2 × A1.

  As can be seen from this equation, when k2 / k1 <m2 / m1, A2 is smaller than A1. Therefore, in the case of steady dehydration operation with a small load, only the short pitch portion 17 with a small spring constant is compressed, so the vibration of the main body is small, and even when the load is large, the repulsion by the long pitch portion 18 with a large spring constant is not. The amplitude at the time of resonance of the vibration system is smaller than when the load is small. In addition, since the long pitch portion 18 has a long pitch, it is difficult to closely contact, and it is possible to prevent the product from being moved due to a collision sound or an impact at the time of contact.

As described above, in the present embodiment, the compression coil spring 16 of the vibration isolator forms a pitch portion 18 having a long pitch at a substantially central portion, and forms pitch portions 17 having a short pitch at both ends thereof. The spring constant when there is no laundry in the washing and dewatering tub 3 is k1, the weight supported by the suspension 9 is m1, and the spring constant when the laundry is contained is k2. When the weight supported by the suspension 9 is m2, the spring constant is set so that k2 / k1 <m2 / m1 even if the weight of the laundry put into the washing and dewatering tub 3 changes. Therefore, the outer frame 1 can be used regardless of whether the laundry put in the washing / dehydrating tub 3 is light or heavy.
In addition, the amplitude at the time of resonance of the vibration system supported by vibration isolation by the vibration isolation device is stably suppressed, and abnormal noise and vibration during dehydration operation can be suppressed.

  As described above, the washing machine according to the present invention can stably suppress the amplitude at the time of resonance of the vibration system regardless of the weight of the laundry, and can suppress abnormal noise and vibration during dehydration operation. The present invention can be applied to other washing machines having a vibration system supported by vibration isolation.

DESCRIPTION OF SYMBOLS 1 Outer frame 2 Water tank 3 Washing and dewatering tank 9 Suspension 16 Compression coil spring 17 Short pitch part 18 Long pitch part

Claims (1)

A washing and dewatering tub for storing laundry, a water tub containing the washing and dewatering tub, and a vibration isolating device for supporting the water tub on an outer frame, wherein the vibration isolating device has a suspension including a compression coil spring. The compression coil spring has short pitch portions on both sides of the long pitch portion;
The compression coil spring has a spring constant k1 when there is no laundry in the washing / dehydrating tub, m1 is the weight supported by the suspension at that time, and the laundry enters the washing / dehydrating tub. The washing machine is characterized in that k2 / k1 <m2 / m1 is set, where k2 is a spring constant and m2 is a weight supported by the suspension at that time.