Patent Application
20090173110
The present invention relates to a washing machine, and more particularly, to a washing machine, which has structure to reinforce fastening bosses formed on a front surface of a tub to mount a balance weight.
Generally, washing machines are classified into pulsator type washing machines which wash laundry using water motion generated by rotating a plate-shaped pulsator, and drum type washing machines which wash the laundry using falling of water and the laundry and frictional force therebetween generated within a horizontally laid tub by rotating the tub.
Among these washing machines, the drum type washing machine has been increasingly demanded in recent years due to its merits over the pulsator type washing machine in that the drum type washing machine uses a smaller amount of water and detergent, and is substantially free from damage and entanglement of the laundry when washing the laundry.
Generally, the construction of the drum type washing machine can be divided into a tub supported by dampers and springs within a cabinet, a cylindrical drum rotatably mounted in the tub, and a driving unit connected with the drum via a shaft to rotate the drum.
The cabinet is provided at a front side thereof with a door corresponding to an opening of the drum, a gasket between the door and the drum to maintain sealing of the drum, and a controller positioned above the door to control operation of the washing machine according to commands input by a user.
Meanwhile, a balance weight is mounted to either side of the front surface of the tub by means of a plurality of fastening ribs formed on the tub, and prevents vibration of the driving unit caused by unbalance of laundry contained within the drum using center of gravity of the balance weight.
For the drum type washing machine constructed as described above, rotational force of a rotor is transmitted to the drum via the shaft, and rotates the drum so that the laundry is lifted by baffles, and then dropped by gravity, thereby performing washing operation.
However, there is a problem in that the fastening bosses serving to mount the balance weights to the tub are damaged due to concentration of vibration from the tub and loads from the balance weights on the respective bosses when the drum rotates at high speeds.
An object of the present invention devised to solve the problem lies on a washing machine adapted to reinforce respective fastening bosses formed on a tub for mounting balance weights to the tub in order to prevent damage of the respective fastening bosses.
The objects of the present invention can be achieved by providing a washing machine, comprising: a tub having a gasket coupling part to which a gasket is coupled; a plurality of fastening bosses formed on a circumference about a central axis of the tub to secure a balance weight; and a plurality of ribs to reinforce the fastening bosses, wherein at least one of the ribs formed in an outer direction of the tub around each fastening boss is thicker than the ribs formed towards a central axis of the tub.
Preferably, the number of ribs formed in the outer direction of the tub is more than those formed towards the central axis of the tub.
Preferably, a connecting portion between the tub and each fastening boss is rounded.
The washing machine may further comprise protrusions formed on a surface of the tub where the respective fastening bosses and the respective ribs are formed.
The washing machine may further comprise at least one circumferential rib protruded circumferentially on the tub.
The circumferential rib may be a first circumferential rib connecting the fastening bosses with each other.
The circumferential rib may be a second circumferential rib between an outer periphery of the tub and the respective fastening bosses.
The circumferential rib may be a third circumferential rib between the gasket coupling part and the respective fastening bosses.
The third circumferential rib may have a height lower than that of a mold line for the gasket coupling part.
In accordance with another aspect of the present invention, a tub for a washing machine is provided, the washing machine comprising a tub having a gasket coupling part to which a gasket is coupled, a plurality of fastening bosses formed on a circumference about a central axis of the tub to secure a balance weight, and a plurality of ribs to reinforce the fastening bosses, wherein at least one of the ribs formed in an outer direction of the tub around each fastening boss is thicker than the ribs formed towards the central axis of the tub.
With this construction, the present invention has advantageous effects as follows.
Firstly, according to the present invention, among the plural ribs to reinforce the fastening bosses, the rib formed at a portion on which stresses are concentrated is formed thicker than the other ribs, thereby preventing the fastening bosses from be damaged due to stress concentration.
Secondly, according to the present invention, the connecting portion between the tub and the fastening bosses is rounded to increase an area thereof so that the stress applied to the connecting portion can be dispersed, thereby preventing the connecting portion from being damaged.
Thirdly, according to the present invention, the ribs are formed along the circumference of the tub while being connected with the respective fastening bosses, thereby multiplying the strength of the tub and the fastening bosses.
Finally, since the present invention prevents the respective fastening bosses from being damaged due to stress concentration upon rotation of the drum at high speeds, reliability for the products can be enhanced.
The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.
In the drawings:
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
First,
As shown in
The washing machine further comprises a control panel 57 on the cabinet 52, a water supply hose 65 and a water supply valve 66 installed at one side of an upper portion inside the cabinet 52 to supply water into the tub 56, and a water drainage hose 68 and a water drainage valve 66 installed at one side of a lower portion inside the cabinet 52 to drain the water from the washing machine.
A gasket coupling part 80 is formed at the front side of the tub 56, and a heater (not shown) is mounted to a lower side of the tub 56 to control temperature of water supplied into the tub 56 and the drum 58. In addition, a motor 62 is secured to a rear side of the tub 56, and connected with the drum 58 to rotate the drum 58.
Here, the gasket coupling part 80 is mounted with a gasket 50 to seal between the door 70 and the input port 11.
Meanwhile, a balance weight 90 is mounted to either side on the front surface of the tub 56, and prevents vibration of the driving unit caused by unbalance of the laundry contained within the drum.
The tub 56 has a plurality of fastening bosses 100 formed along a circumference about a central axis of the tub 56 to mount the balance weights 90 to the tub such that the balance weights 90 are fastened to the fastening bosses 100 by means of bolts B.
According to the embodiment, a plurality of ribs is formed to reinforce the fastening bosses 100. Among the ribs around each of the fastening bosses 100, at least one of the ribs (which will be referred to as first ribs 310) formed in an outer direction of the tub 56 are preferably thicker than the ribs (which will be referred to as second ribs 330) formed towards the central axis of the tub 56.
Preferably, the number of first ribs 310 is more than the number of second ribs 330.
With a result of analyzing stress applied to each rib through the balance weight 90 when the drum 58 is rotated at a high speed of, for example, 1,600 rpm, it can be appreciated that the first ribs 310 are subjected to a higher stress than the second ribs 330, as shown in
Accordingly, since the first ribs 310 are likely to be broken in comparison to the second ribs 330, it is desirable that the thickness of first ribs 310 be higher than that of the second ribs 330, and the number of first ribs 310 be more than the number of second ribs 330.
At this time, in this embodiment, as shown in
Preferably, each of connecting portions between the tub 56 and the respective fastening bosses 100 is rounded.
In other words, when forming the connecting portion between the tub 56 and the respective fastening bosses 100 into a round shape, an area of the connecting portion between the tub 56 and the fastening bosses 100 is increased, and vibration of the tub 56 and the stress transmitted through the balance weights 90 are dispersed, thereby preventing damage of the connecting portion between the tub 56 and the fastening bosses 100.
Meanwhile, according to the embodiment, the tub may further comprise protrusions 400 at portions where the respective fastening bosses 100 and the respective ribs 310 and 330 are formed.
With the protrusions 400, it is possible to further reinforce the respective fastening bosses 100 and the respective ribs 310 and 330.
According to this embodiment, the tub 56 has at least one circumferential rib circumferentially protruded thereon in order to multiply the strength of the tub 56 and the fastening bosses 100. In this embodiment, three circumferential ribs are formed.
The circumferential ribs may comprise a first circumferential rib 510 formed to connect the fastening bosses 100 with each other, a second circumferential rib 530 formed between an outer periphery of the tub 56 and the respective fastening bosses 100, and a third circumferential rib 550 between the gasket coupling part 80 and the respective fastening bosses 100.
Here, the first circumferential rib 510 may be formed to connect the respective fastening bosses 100 with each other while extending to outer peripheral surfaces of the respective fastening bosses 100.
The second circumferential rib 530 is preferably formed between the outer periphery of the tub 56 and the respective fastening bosses 100 such that distal ends of the respective first ribs 310 formed in the outer direction of the tub 56 are connected with the second circumferential rib 530.
The structure wherein the second circumferential rib 530 is formed to connect with the first ribs 310 is provided for the purpose of allowing the stress applied to the respective fastening bosses 100 to be dispersed to the second circumferential rib 530 through the first ribs 310.
In addition, the third circumferential rib 550 is preferably formed between the gasket coupling part 80 and the respective fastening bosses 100 such that distal ends of the respective second ribs 330 formed towards the center of the tub 56 are connected with each other via the third circumferential rib 550.
The structure wherein the second ribs 330 are connected with the third circumferential rib 550 is provided for the purpose of allowing the stress applied to the respective fastening bosses 100 to be dispersed to the third circumferential rib 550 via the second ribs 330.
Meanwhile, the height of the third circumferential rib 550 is preferably lower than a mold line L of the gasket coupling part 80.
More specifically, when the tub 56 is produced using two molds (not shown), one of which is referred to as a first mold to form the gasket coupling part 80 and the other of which is referred to as a second mold to form remaining parts of the tub 56, the mold line L is formed on the tub 56 along a separation part between the first and second molds.
That is, it is preferable that the height of the third circumferential rib 550 is lower than the mold line L in order to prevent a portion of the second mold to form the third circumferential rib 550 from interfering with the first mold when separating the first mold during a process of separating the molds.
Operation of the embodiment according to the present invention described above will be described as follows.
With fastening bosses 100 formed on a front surface of the tub 56 to mount balance weights 90 to the tub, plural ribs are placed near an associated fastening boss 100 such that the rib formed corresponding to a portion likely to suffer from concentration of stress is formed thicker than other ribs. In addition, protrusions are formed on respective portions where the fastening bosses 100 and the respective ribs are formed, and circumferential ribs are formed on the tub 56 in order to further reinforce the fastening bosses 100. With this structure, even if vibration caused by rotation of the drum at high speeds and stress caused by the load of the balance weights 90 are concentrated on the respective fastening bosses 100, the fastening bosses 100 can endure the vibration and the stress, and thus, can be prevented from breaking.
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 invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
The present invention has industrial applicability in that, since the tub and the fastening bosses formed on the front side of the tub are reinforced, even if vibration caused by rotation of the drum at high speeds and stress caused by the load of the balance weights are concentrated on the respective fastening bosses, the fastening bosses can endure vibration and stress, and can be prevented from breaking, thereby increasing satisfaction of consumers with respect to the corresponding products.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR06/01634 | 5/2/2006 | WO | 00 | 10/31/2008 |
