US20080210179A1

US20080210179A1 - Steam Generator and Laundry Machine Comprising the Same

Info

Publication number: US20080210179A1
Application number: US11/629,384
Authority: US
Inventors: Seog Kyu Park
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2005-03-17
Filing date: 2006-03-13
Publication date: 2008-09-04
Also published as: DE112006000076B4; WO2006098573A1; KR20060100604A; DE112006000076T5

Abstract

The present invention relates to laundry machines, and more particularly, to a steam generator for a laundry machine and a laundry machine with the same. The present invention provides a steam generator including a case having a space for turning water into steam, a heater for heating the water for generating the steam, and at least two overheating preventive means for preventing overheating of the heater, and a laundry machine with the same.

Description

TECHNICAL FIELD

The present invention relates to laundry machines, and more particularly, to a steam generator for a laundry machine and a laundry machine with the same.

BACKGROUND ART

In general, of washing machines, a drum type washing machine, washing laundry by using friction between a drum rotated by a motor and the laundry in a state detergent and washing water, and the laundry is introduced to the drum, has almost no damage, or entangling of the laundry, and can provide a washing effect of rubbing and pounding the laundry.
FIG. 1 illustrates a longitudinal section of a related art drum type washing machine.
Referring to FIG. 1, the related art drum type washing machine is provided with a body 10 of an exterior thereof, a tub 20 in the body 10, a drum 30 rotatably mounted in the tub 20 having lifters 35 on an inside circumferential surface, and driving means 70 for driving the drum 30.
On a front of the body 10, There is a door 40 provided to a predetermined position so as to be matched with an opening in the drum 30, with a gasket 50 between the door 40 and the drum 30 for maintaining sealing of the drum 30.
The tub 20 has dampers at opposite lower sides of an outside circumference secured to the body 10.
The driving means 70 is provided with a driving motor 71 for driving the drum 30, and a belt 72 connected to a belt pulley 73 for transmission of a driving power from the driving motor 71 to the drum 30.
If a user gives an order to perform general washing, a controller (not shown) of the drum type washing machine which controls operation of the washing machine progresses washing, rinsing, final spinning in succession, to washing the laundry.
In the washing, separation of dirt is made by means of the detergent, and by means of impact, friction, and bending and stretching caused by continuous lifting and dropping of the laundry by the lifters 35 as the drum 30 is rotated continuously.
In the rinsing, the step of rinsing is performed, in which residual detergent and dirt produced as the washing is progressed by supplying new washing water and repetitive rotation of the drum 30 is separated from the laundry.
In the final spinning, the drum 30 is rotated at a high speed (approx. 800 RPM˜1300 RPM) to remove moisture from the laundry.
Moreover, recently, for reducing power consumption and washing water used for the washing, a drum type washing machine having a steam generator 80 mounted thereto is provided.
Referring to FIG. 2, a related art steam generator 80 is provided with a case 82 of an exterior thereof to form a space for holding water, and a heater 84 for heating the water.
The case 82 has one side with a water inlet (not shown) connected to a water supply pipe (not shown) for introduction of water to an inside of the case 82, and the other side with an outlet (not shown) connected to a steam supply pipe (not shown) or the like for supplying steam generated by heating the water introduced thereto with the heater 84 to the drum 30 of the washing machine.
It is preferable that the heater 84 is mounted on a lower side of the case 82 for heating the water directly in a state the heater 84 is submerged in the water held in the case 82 completely.
In this instance, a sheath heater is suitable for the heater, which has a high heat efficiency and can heat the water within a short time period.
In the meantime, there is a temperature sensor 88 at a center of the case 82 for measuring a temperature of the water in the case 82.
Moreover, there is overheating preventive means 86, such as thermo-fuse, at one end of the heater 84 for preventing the heater 84 from being overheated to damage the heater 84 itself and components around the heater 84.
The overheating preventive means 86 is designed to be short circuited in a case the heater 84 is overheated, to cut off power to the heater 84, to prevent the heater 84 from being overheated anymore.
The operation of the related art steam generator of a washing machine will be described.
Upon starting the washing, the water is supplied to the case 82 through the water inlet.
The water introduced to the case 82 is heated with the heater 84, and is turned into steam, and the steam is introduced to the drum 30 holding the laundry through the outlet (not shown) in the case 82, to improve washing efficiency by wetting and soaking of the laundry.
After finishing the wetting and soaking of the laundry, the steam generator 80 is stopped, and a series of washing steps are performed, to finish the washing
However, the related art steam generator of the washing machine has the following drawbacks.
First, referring to FIG. 3, the steam generator 80 can be tilted due to negligence of the worker or failure of installation of the washing machine in a horizontal position.
If a water level of the steam generator 80 becomes low under above state, to expose one end of the heater 84 over the water surface, the expose portion is overheated as the heater 84 is kept operated.
In this instance, since the overheating preventive means 86 at one side end of the heater 84 is in a submerged state, the overheating preventive means 86 fails to sense overheating of the exposed end of the heater 84, and the temperature sensor 88, at the center of the case 82 submerged in the water, also fails to sense the overheating of an inside of the case.
Consequently, as the heater 84 fails to stop, but is kept overheating, the case 82 is likely to deform by the heat from the heater 84, or if it is excessive, the case 82 deformed by the heat is come into contact with the heater 84 to cause an outbreak of fire.

DISCLOSURE OF INVENTION

Technical Problem

An object of the present invention is to provide a steam generator for a laundry machine, in which the heater is not overheated, to cause thermal deformation or outbreak of fire even if the steam generator is tilted; and a laundry machine having the same.

Technical Solution

The object of the present invention can be achieved by providing a steam generator for a laundry machine including a case having a space for turning water into steam, a heater for heating the water for generating the steam, and at least two overheating preventive means for preventing overheating of the heater.
It is preferable that the overheating means is means for cutting off power to the heater, actually.
In more detail, the overheating preventive means includes at least one of a thermo-fuse, thermister, and thermostat. That is, the overheating preventive means can prevent overheating of the heater by means of permanent or selective electric short circuit or substantial electric short circuit owing to a very high resistance.
Preferably, the overheating preventive means includes first overheating preventive means at one side of the heater, and second overheating means at the other side of the heater. That is, if there are a plurality of overheating preventive means, it is preferable that the overheating preventive means are provided at opposite sides.
Preferably, the first overheating preventive means and the second overheating preventive means are of types different from each other.
In the meantime, in another aspect of the present invention, a steam generator for a laundry machine includes a case having a water inlet for introduction of water thereto, an outlet for discharging steam, and a receiver for holding water introduced thereto, a heater for heating the water in the case for generating the steam, and at least two overheating preventive means for preventing overheating of the heater.
Preferably, the heater is mounted in the receiver of the case, and a sheath heater. Preferably, the heater is mounted such that the heater is passed through one side wall of the case and extended toward a direction of a side wall opposite the one side wall.
Preferably, the overheating preventive means includes first overheating preventive means in the vicinity of one side wall of the case, and second overheating means in the vicinity of a side wall opposite to the one side wall.
Preferably, the first overheating preventive means senses overheating of the heater by means of thermal conduction substantially, and more specifically, may be a thermo-fuse, or thermostat.
On the other hand, preferably the second overheating preventive means senses overheating of the heater by means of radiation of convection of heat substantially, and more specifically, may be a thermister having a resistance varied with a temperature. Preferably, the resistance of the thermister rises sharply if a temperature of the heater is higher than a reference temperature, to cat off power to the heater, substantially. Of course, the types of the first overheating means and the second overheating means may be interchanged.
In another aspect of the present invention, a laundry machine includes a body of an exterior of the laundry machine, a tub in the body, a drum rotatably mounted in the tub, and a steam generator for supplying steam to the tub or the drum, wherein the steam generator includes a case having a water inlet for introduction of water thereto, an outlet for discharging steam, and a receiver for holding water introduced thereto, a heater for heating the water in the case for generating the steam, and a plurality of overheating preventive means of types different from one another for preventing overheating of the heater.
The plurality of overheating preventive means may include first overheating preventive means on one side of the heater in the case, and second overheating means on the other side of the heater.

ADVANTAGEOUS EFFECTS

The steam generator for a washing machine of the present invention has the following advantages.
First, since the second overheating preventive means senses overheating of the heater, and stops the heater even if the heater is overheated due to exposure of the other end of the heater coming from tilting of the steam generator, thermal deformation of the case and outbreak of fire can be prevented, to improve safety of the product.
The prevention of overheating of the end of the heater improves a lifetime and safety of the heater.
Third, the provision of different types of overheating preventive means permits to prevent the overheating of the heater with high reliability, to prevent damage coming from overheating of the heater.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings;

FIG. 1 illustrates a longitudinal section of a related art drum type washing machine;

FIG. 2 illustrates a perspective view of a related art steam generator, with a partial cut away view;

FIG. 3 illustrates a diagram of the steam generator in FIG. 2 when the steam generator is tilted;

FIG. 4 illustrates a perspective view of a steam generator for a washing machine in accordance with a preferred embodiment of the present invention;

FIG. 5 illustrates a bottom view of the steam generator in FIG. 4 seen from an inside thereof; and

FIG. 6 illustrates a diagram of the steam generator in FIG. 4 when the steam generator is tilted.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 4 illustrates a perspective view of a steam generator for a washing machine in accordance with a preferred embodiment of the present invention, FIG. 5 illustrates a bottom view of the steam generator in FIG. 4 seen from an inside thereof, and FIG. 6 illustrates a diagram of the steam generator in FIG. 4 when the steam generator is tilted.
Referring to FIGS. 4 and 5, the steam generator 180 includes a case having a space for turning water into steam, a heater for heating the water for generating the steam, and at least two overheating preventive means for preventing overheating of the heater.
The case 182 has a water inlet 181 at one side, and an outlet 183 at the other side for discharging steam generated as the water introduced through the water inlet 181 is heated toward a drum 30 (see FIG. 1). The case 182 has a predetermined volume for holding a predetermined amount of water.
There is a heater 184 for heating the water in the case 182. It is preferable that the heater 184 mounted to a lower side of the case 182 for heating the water even if a water level in the case 182 is low.
Moreover, it is preferable that the heater is a sheath heaters which has high thermal efficiency and can heat the water within a comparatively short time period.
Referring to FIGS. 4 and 5, it is preferable that the heater 184 is mounted such that the heater 184 is passed thrash one side wall of the case 182, and extended to an opposite side wall of the one side wall, for easy detachment of the heater.
The heater 184 includes first overheating preventive means 186 for preventing overheating of the heater 184.
It is preferable that the first overheating preventive means 186 is a thermo-fuse at one end of the heater 184 for short circuiting at overheating of the heater 184 to cut off power to the heater 184, for preventing overheating of the heater 184. That is, in a case the overheating of the heater is prevented by using such a thermo-fuse, it is required to replace the thermo-fuse with new one because the thermo-fuse is short circuited, permanently.
FIG. 4 illustrates a thermo-fuse 186 mounted between both ends of the heater for easy replacement of the thermo-fuse 186, and FIG. 5 illustrates a thermo-fuse 186 at both ends of the heater.
In a case of the thermo-fuse illustrated in FIG. 4, though heat of the heater is transmitted to the thermo-fuse, not directly, but indirectly thrash other media, but, in a case of the thermo-fuse illustrated in FIG. 5, the heat of the heater is transmitted to the thermo-fuse directly. According to this, the first overheating preventive means has the heat of the heater transmitted thereto by thermal conduction, substantially.
Moreover, besides the first overheating preventive means 186, there is second overheating preventive means 188 for measuring a temperature of the water in the case 182 or an inside of the case 182.
In more detail, it is preferable that the second overheating preventive means 188 is placed in the case 182 through a top surface thereof at a position opposite to the first overheating preventive means 186 at one end of the heater 184, i.e., at the other end of the heater 184.
This is for measuring radiant heat emitted from the other end of the heater 184 as the second overheating means 188 is mounted over the other end of the heater 184. Of course, the heat from the heater can be transmitted to the second overheating preventive means through the steam in the steam generator or convection of the air. Therefore, the second overheating preventive means senses overheating by means of radiation, or convection, substantially.
It is preferable that the power to the heater 184 is cut off for preventing the heater 184 from emitting no more heat, if the heat sensed at the second overheating preventive means 188 is higher than a reference temperature.
In this instance, though it is preferable that the reference temperature is a temperature a material of the case 182 can resist, since the temperature is varied with the material, and a detailed structure of the inside of the case 182, detailed description of which will be omitted.
Accordingly, the second overheating preventive means 188 serves to prevent overheating and deformation of the case 182 by measuring radiant heat emitted from the other end of the heater 184, and cutting off the power to the heater 184 if the radiant heat is higher than the reference temperature.
The second overheating means 188 may be a thermister having a resistance varied with the heat measured. In this case, it is preferable that the resistance of the thermister rises sharply at a temperature higher than the reference temperature where it is determined that the heater is overheated. That is, a very high resistance cuts off the power to the heater, actually. In other words, though the thermister does not short circuit physically, it can be assumed that a short circuit is made, substantially.
In the meantime, besides the thermister, as the second overheating means 188, a thermostat may be used, of which volume expands, and contracts according to heat. That is, the thermostat is designed to cut off a current to the heater 184 as the thermostat expands thermally if the other end of the heater 184 is overheated. As one example of the thermostat, a bimetal may be used.
Since a structure of the thermostat for cutting off the current to the heater 184 is known, a detailed description of which will be omitted.
If is preferable that the second overheating preventive means and the second overheating preventive means is overheating preventive means having types different from each other for preventing overheating of the heater with higher reliability, inclusive of heat sensing structures and major heat transfer types.
For an example, if the first overheating preventive means is of a thermostat type that senses heat in a mode of radiation, the second overheating preventive means may be a thermo-fuse for sensing the heat in a mode of heat transfer.
In the meantime, though not shown, there may be a water level sensor (not shown) for measuring a water level of the in the case 182.
Therefore, in the steam generator for the washing machine of the present invention, the water is introduced to the case 182 through the water inlet 181, the heater 184 heats water introduced to the case 182 to generate steam, and the steam generated thus is supplied to the drum 30 (see FIG. 1) through the outlet 183.
By detecting a remained amount of water in the case 182 by the water level sensor (not shown), overheating of the heater 184 is prevented, caused by operation of the heater 184 despite of shortage of water in the case 182.
Moreover, in a case the heater 184 is overheated by unexpected fault or malfunction, the first overheating means 186 cuts of the current to the heater 184, to prevent any more overheating of the heater 184.
In this instance, referring to FIG. 6, because the washing machine is tilted due to reasons, such as installation of the washing machine on a floor which is not horizontal, or the steam generator 180 is assembled in a non-horizontal state due to mistake of a worker, the first overheating means 186 may not function, properly.
In more detail, in a case the steam generator 180 is tilted such that a portion of the first overheating preventive means 186 of the heater 184 is submerged in the water, and an opposite end of the portion the first overheating preventive means 186 is mounted is exposed from a water surface, since a neighborhood of the heater 184 having the first overheating preventive means 186 mounted thereon is submerged in the water, the heater 184 is kept operating.
However, because the opposite end of the portion having the first overheating preventive means 186 mounted thereon of the heater 184 is exposed from the water surface, to fail to be cooled down by the water, but overheated, the opposite end emits radiant heat to an environment.
In this instance, since the second overheating preventive means 188 is positioned over the opposite end of the portion where the first overheating preventive means 186 of the heater 184 is mounted, the second overheating preventive means 188 measures radiant heat emitted from the heater 184 exposed from the water surface, to stop operation of the heater 184 if the heater 184 is overheated over the reference temperature.
Of course, in a case the steam generator is tilted opposite to the position illustrated in FIG. 6, since the first overheating preventive means is exposed from the water surface even if the second overheating preventive means is submerged in the water, the overheating of the heater can be prevented by the first overheating preventive means.
Therefore, according to the steam generator for a washing machine of the present invention, deformation or outbreak of fire caused by overheating of the heater 184 can be prevented.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

Included to the detailed description of the present invention.

Claims

1. A steam generator for a laundry machine comprising:

a case having a space to turn water into steam;

a heater to heat the water and to generate the steam; and

at least a first and second overheating preventers to prevent overheating of the heater, wherein the first overheating preventer is located at one side of the heater and the second overheating preventer is located at the other side of the heater.

2. The steam generator as claimed in claim 1, wherein at least one of the first and second overheating preventers includes a thermo-fuse.

3. The steam generator as claimed in claim 2, wherein the thermo-fuse is provided to cut off a current to the heater when the heater is overheated.

4. The steam generator as claimed in claim 1, wherein at least one of the first and second overheating preventer includes a thermister.

5. The steam generator as claimed in claim 1, wherein at least one of the first and second overheating preventer includes a thermostat.

6. (canceled)

7. The steam generator as claimed in claim 1, wherein the first overheating preventer and the second overheating preventer are of different types.

8. A steam generator for a laundry machine comprising:

a case having a water inlet to receive water and an outlet to discharge steam;

a heater to heat the water in the case to generate the steam; and

9. The steam generator as claimed in claim 8, wherein the heater is mounted in the case.

10. The steam generator as claimed in claim 9, wherein the heater is a sheath heater.

11. The steam generator as claimed in claim 10, wherein the heater is mounted such that the heater passes through one side wall of the case and extends toward a direction of a side wall opposite the one side wall.

12. The steam generator as claimed in claim 11, wherein

the first overheating preventer is in the vicinity of the one side wall of the case and

the second preventer is in the vicinity of the side wall opposite to the one side wall.

13. The steam generator as claimed in claim 8, wherein the first overheating preventer and the second overheating preventer are of different types.

14. The steam generator as claimed in claim 13, wherein the first overheating preventer senses overheating of the heater through of thermal conduction.

15. The steam generator as claimed in claim 14, wherein the first overheating preventer is a thermo-fuse or a thermostat.

16. The steam generator as claimed in claim 13, wherein the second overheating preventer senses overheating of the heater through heat convection.

17. The steam generator as claimed in claim 16, wherein the second overheating preventer is a thermister having a resistance that varies with temperature.

18. The steam generator as claimed in claim 17, wherein the resistance of the thermister rises sharply if a temperature of the heater is higher than a reference temperature, to substantially cut off power to the heater.

19. A laundry machine comprising:

a body;

a drum rotatably mounted in the body; and

a steam generator to generate steam to be supplied into the drum,

wherein the steam generator includes;

a case having a water inlet to receive water and an outlet to discharge the steam,

a heater to heat the water and to generate the steam,

first overheating preventer located at one side of the heater, and

second overheating preventer located at the other side of the heater.

20. The laundry machine as claimed in claim 19, wherein

the first overheating preventer and the second overheating preventer are of different types.