CN111387899B

CN111387899B - Cleaning device

Info

Publication number: CN111387899B
Application number: CN202010424495.6A
Authority: CN
Inventors: 林孝发; 林孝山; 张传义
Original assignee: Jomoo Kitchen and Bath Co Ltd
Current assignee: Jomoo Kitchen and Bath Co Ltd
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2024-08-06
Anticipated expiration: 2040-05-19
Also published as: CN111387899A

Abstract

The application discloses a cleaning device, wherein a spray arm of the cleaning device is provided with a first support arm, a second support arm and a connecting part for connecting a spray seat, and the connecting part is provided with a first clamping protrusion and a second clamping protrusion which are respectively positioned below the first support arm and the second support arm; the first clamping protrusion and the second clamping protrusion are slidably clamped on the spray seat in the rotation process of the spray arm so as to prevent the spray arm from being separated from the spray seat; when the first support arm points to all corners of the cleaning cavity, the clamping points of the first clamping protrusion and the spraying seat are lower than the clamping points of the first clamping protrusion and the spraying seat when the first support arm points to the side of the cleaning cavity. Therefore, the technical scheme of the application enlarges the cleaning coverage area when the first support arm points to the corner of the cleaning cavity, and realizes the technical effect of cleaning bowls and chopsticks in four corners.

Description

Cleaning device

Technical Field

The present application relates to the field of household cleaning devices, and in particular to kitchen cleaning devices, such as dishwashers.

Background

The existing dish washing machine is generally designed into a square shape because of factors such as installation, space and in order to place more bowls and chopsticks, and the cleaning cavity in the washing tank of the dish washing machine is generally designed into a square shape, the spraying area of the spraying arm after rotation is round, and meanwhile, in order to clean the bowls and chopsticks as much as possible, the spraying round area of the spraying arm is as close to the largest inscribed round area of the square shape as much as possible. Therefore, four corners in the square cleaning cavity are still harder to be in the circular spraying area of the spray arm, and bowls and chopsticks in the four corners are easier to wash cleanly in the bowl washing process.

Disclosure of Invention

The present application has been made to overcome the above-mentioned drawbacks or problems occurring in the prior art, and an object of the present application is to provide a cleaning device capable of cleaning bowls and chopsticks in four corners.

In order to achieve the above purpose, the following technical scheme is adopted:

a cleaning device comprising: a cleaning tank provided with a square cleaning cavity; the spray seat is fixed relative to the cleaning tank, and the water outlet end of the spray seat is positioned in the cleaning cavity; the spray arm is supplied with water by the spray seat and sprays the water into the cleaning cavity, and the spray arm rotates relative to the cleaning tank under the reaction force of water flow; the spray seat is provided with a first support arm, a second support arm and a connecting part, wherein the first support arm and the second support arm extend in opposite directions; the connecting part is provided with a first clamping protrusion and a second clamping protrusion which are respectively positioned below the first support arm and the second support arm; the first clamping protrusion and the second clamping protrusion are slidably clamped on the spray seat in the rotation process of the spray arm so as to prevent the spray arm from being separated from the spray seat; when the first support arm points to the four corners of the cleaning cavity, the clamping points of the first clamping protrusion and the spraying seat are lower than the clamping points of the first clamping protrusion and the spraying seat when the first support arm points to the side of the cleaning cavity.

Further, the spraying seat is provided with a first track surface and a second track surface; the first track surface is positioned below the second track surface; the first track surface and the second track surface are downward closed surfaces, and the projection of the first track surface and the second track surface on the horizontal plane is annular; the first track surface and the second track surface are wavy and are opposite in phase after being horizontally unfolded; the parts of the first track surfaces, which point to the corners of the cleaning cavity, are all downward convex; the first clamping protrusion and the second clamping protrusion respectively push against the first track surface and the second track surface to realize clamping connection.

Further, the spray seat is provided with a first flange and a second flange; the first flange is positioned below the second flange; the lower surface of the first flange and the lower surface of the second flange respectively form a first track surface and a second track surface; the lower surfaces of the first support arm and the second support arm are respectively provided with a first clamping claw and a second clamping claw which extend towards the rotating shaft of the spray arm.

Further, the spray seat is provided with a rotating cavity which is opened upwards; the rotating cavity is communicated with a water inlet channel of the spray seat; the connecting part is provided with a connecting ball head which extends downwards from the lower surface of the spray arm along the rotation axis of the spray arm, and a connecting water channel communicated with the spray water channel in the spray arm is arranged in the connecting ball head; the connecting water channel is opened at the top end of the connecting ball head; and when the first clamping protrusion and the second clamping protrusion are respectively clamped with the first track surface and the second track surface, the connecting ball head is matched with the spherical surface of the rotating cavity.

Further, when the first support arm points to the edge of the cleaning cavity, the rotating shaft of the spray arm is vertical.

Further, when the ratio between the length of the longest side of the cleaning tank and the length of the spray arm is greater than 1.0 and smaller than 1.3, the included angle between the rotating shaft of the spray arm when the first support arm points to the corner of the cleaning cavity and the rotating shaft of the spray arm when the first support arm points to the side of the cleaning cavity is smaller than 8 degrees.

Further, the first support arm is provided with a first nozzle which is farthest from the rotating shaft of the spray arm, the spraying direction of the first nozzle and the perpendicular line from the first nozzle to the rotating shaft of the spray arm are positioned on the same vertical plane, and an included angle between the first nozzle and the perpendicular line is an obtuse angle.

Further, the included angle is less than 106 ° when the ratio between the length of the longest side of the cleaning tank and the length of the perpendicular line from the first nozzle to the rotation axis of the spray arm is greater than 1.0 and less than 1.3.

Further, the second support arm is provided with a second nozzle which is farthest from the rotating shaft of the spray arm, and an included angle exists between the spraying direction of the second nozzle and the vertical plane where the perpendicular line from the second nozzle to the rotating shaft of the spray arm is located.

Compared with the prior art, the scheme has the following beneficial effects:

Because the clamping points of the first clamping protrusion and the spraying seat are lower than the clamping points of the first clamping protrusion and the spraying seat when the first support arm points to the four corners of the cleaning cavity, the spraying arm inclines towards the corners when the first support arm points to the corners, so that the cleaning area of the nozzle on the first support arm is enlarged, and bowls and chopsticks in four corners can be cleaned.

The first track surface and the second track surface are wavy and are opposite in phase after being horizontally unfolded; the parts of the first track surfaces, which point to the corners of the cleaning cavity, are all downward convex; the first blocking protrusion abutting against the first track surface is sunk when the first support arm points to the corner, so that the spray arm is driven to incline to the corner.

Two clamping protrusions matched with the two wavy track surfaces are forced to continuously incline when the first support arm points to the corner by the two wavy track surfaces arranged on the two flanges so as to drive the first support arm to incline downwards. It should be noted that only one continuous wave-like track surface cannot guarantee that two snap-fit protrusions of the two snap-fit protrusions are inclined downward when the first arm is directed to four corners, but at most can only be inclined downward when the first arm is directed to two corners, and the other two corners inevitably incline upward. This is because in a square wash chamber, the two opposite corners are opposite each other and the two arms are also facing away from each other, in order for the first arm to be inclined down towards one of the opposite corners, it must be inclined up towards the other of the opposite corners, instead reducing the spray area. Therefore, only if two track surfaces are arranged, the two clamping protrusions are respectively clamped with the two track surfaces, and the first support arm can be inclined downwards when pointing to four corners.

Through the spherical cooperation of connecting bulb and rotating the chamber for the swing of spray arm on the perpendicular can regard spherical complex sphere center as the axle center, also can satisfy spray arm pivoted demand simultaneously, the pivot when spray arm rotates is through this spherical complex sphere center all the time.

When the first support arm points to the side part of the cleaning cavity, the rotating shaft of the spray arm is vertical, so that the cleaning effect of the spray arm when pointing to the side part is ensured, and the condition that the cleaning effect is reduced due to the fact that sprayed water flow is sputtered to the inner wall of the cleaning cavity is avoided.

When the ratio of the length of the longest side of the cleaning tank to the length of the spray arm is greater than 1.0 and less than 1.3, the included angle between the rotating shaft of the spray arm when the first support arm points to the corner of the cleaning cavity and the rotating shaft of the spray arm when the first support arm points to the side of the cleaning cavity is less than 8 degrees, so that the situation that the cleaning effect is reduced due to the fact that the sprayed water flow is sputtered to the side wall of the cleaning cavity due to the overlarge included angle can be avoided.

The nozzle at the edge of the first support arm is the first nozzle, the spraying direction of the first nozzle and the perpendicular line from the first nozzle to the rotating shaft of the spray arm are located on the same vertical plane, and when the first support arm points to the corner, the first nozzle can spray on bowls and chopsticks at the corner.

When the ratio between the length of the longest side of the cleaning tank and the length of the spray arm is more than 1.0 and less than 1.3, the included angle is less than 106 degrees, and the situation that the cleaning effect is reduced due to the fact that the sprayed water flow is sputtered to the inner wall of the cleaning cavity due to the fact that the included angle is too large can be avoided.

The nozzle on the second support arm which is farthest from the rotation axis of the spray arm is the second nozzle, an included angle exists between the spraying direction of the second nozzle and a vertical plane where a perpendicular line from the second nozzle to the rotation axis of the spray arm is located, and the maximum moment can be provided for the rotation of the spray arm.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments, the following brief description of the drawings is provided, in which:

FIG. 1 is a schematic view of a cleaning apparatus according to an embodiment;

FIG. 2 is a perspective view of a spray arm in an embodiment;

FIG. 3 is a schematic view of the structure under the shower arm in an embodiment;

FIG. 4 is a perspective view of the water outlet end of the shower tray of the embodiment;

FIG. 5 is a schematic view showing the state of the spray arm when the first arm is directed to the edge of the cleaning chamber in the embodiment;

FIG. 6 is a schematic view showing the spray arm when the first arm is directed to the corner of the cleaning chamber in an embodiment.

The main reference numerals illustrate:

The cleaning device 10, the cleaning tank 1, the spray seat 2, the spray arm 3 and the bowl basket 4;

a first flange 21, a first raceway surface 211, a second flange 22, a second raceway surface 221, a rotation chamber 23, and a water inlet channel 24;

The first support arm 31, the first nozzle 311, the second support arm 32, the second nozzle 321, the connecting part 33, the first claw 331, the first clamping protrusion 3311, the second claw 332, the second clamping protrusion 3321, the connecting ball 333 and the connecting water channel 3331.

Detailed Description

In the claims and in the description, unless otherwise defined, the terms "first," "second," or "third," etc., are used for distinguishing between different objects and not for describing a particular sequential order.

In the claims and the specification, unless otherwise defined, the terms "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inner", "outer", "upper", "lower", "front", "rear", "left", "right", "clockwise", "counterclockwise", etc., refer to an orientation or positional relationship based on that shown in the drawings, and are merely for convenience of description, and do not imply that the devices or elements referred to must have a particular orientation or be constructed and operated in a particular orientation.

In the claims and specification, unless otherwise defined, the terms "fixedly coupled" and "fixedly connected" are to be construed broadly as any manner of connection without a displacement relationship or relative rotational relationship therebetween, and that is to say include non-detachably fixedly connected, integrally connected, and fixedly connected by other means or elements.

In the claims and specification, unless otherwise defined, the terms "comprising," having, "and variations thereof mean" including but not limited to.

The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings.

Referring to fig. 1, fig. 1 shows a cleaning device 10 in an embodiment. As shown in fig. 1, the cleaning device 10 in this embodiment is a tub-type dishwasher, which includes a cleaning tub 1, a spray base 2, a spray arm 3, and a bowl basket 4, and since other components of the cleaning device in the embodiment are not different from those of the tub-type dishwasher in the prior art, the description thereof will not be repeated.

Of these, the washing tank 1 is a square-shaped water tank in which the sink type dishwasher is located, and of course, the washing tank 1 is not limited to the water tank of the sink type dishwasher, and may be any object which accommodates an object to be washed and performs a washing operation therein. The cleaning tank 1 in this embodiment is characterized in that a top cover is further provided on the top of the cleaning tank 1, and the top cover is hinged to the cleaning tank 1 and is rotatable between an open position and a closed position. The square cavity enclosed by the cleaning tank 1 and used for accommodating the objects to be cleaned is a cleaning cavity. The bowl basket 4 is placed in the washing chamber and sits on the bottom of the washing tub 1. Since the bowl basket 4 is provided with supporting legs as in the prior art, a space for the spray arm 3 to rotate is formed between the bottom lower surface of the bowl basket 4 and the bottom upper surface of the tub bottom of the tub 1.

Referring to fig. 1,4 and 5, in the present embodiment, as shown in fig. 1, a spray seat 2 is fixedly connected to a bottom of a cleaning tank 1, and a water outlet end is located in a cleaning cavity. Of course, the spray seat 2 may be disposed on a water collecting cup and fixed relative to the cleaning tank 1 by the water collecting cup. As in the prior art, the shower base 2 is generally located at the center of the tank bottom of the cleaning tank 1. As shown in fig. 4, the water outlet end of the shower base 2 is provided with a first flange 21 located below and a second flange 22 located above. The outer diameter of the second flange 22 is smaller than the outer diameter of the first flange 21. The lower surface of the first flange 21 forms a first raceway surface 211 and the lower surface of the second flange forms a second raceway surface 221. The first track surface 211 and the second track surface 221 are downward closed surfaces, and the projections of the first track surface 211 and the second track surface 221 on the horizontal plane are annular; if the first and second track surfaces 211 and 221 are horizontally unfolded on the vertical plane, it can be seen that the first and second track surfaces 211 and 221 are both wavy and have exactly opposite phases with respect to the angle, i.e. under the same angle, the downward convexity of the first track surface 211 corresponds to the upward convexity of the second track surface 221 and the upward convexity of the first track surface 211 corresponds to the downward convexity of the second track surface 221. After the shower base 2 in this embodiment is connected to the cleaning tank 1, the portions of the first raceway surface 211 facing the corners of the cleaning chamber are all convex downward, and the portions of the first raceway surface 211 facing the sides of the cleaning chamber are all concave upward, whereby the first raceway surface 211 has four lower convex portions corresponding to the four corners of the cleaning chamber respectively and four upper concave portions corresponding to the four sides of the cleaning chamber respectively located between the adjacent lower convex portions. Of course, since the second raceway surface 221 is inverted from the first raceway surface 211, the second raceway surface 211 has four upper concave portions corresponding to four corners of the cleaning chamber and four lower convex portions corresponding to four sides of the cleaning chamber located between adjacent upper concave portions. As shown in fig. 5, the spraying seat 2 is further provided with a rotating cavity 23 which is opened upwards at the water outlet end thereof and a water inlet channel 24 which is communicated with the rotating cavity 23 along the axial direction, in this embodiment, the cavity bottom of the rotating cavity 23 is spherical, and the water inlet channel 24 extends downwards from the cavity bottom of the rotating cavity 23 to the water inlet end and is communicated with the water outlet end of the circulating water pump.

See fig. 2, 3 and 6. As shown in fig. 5, in the present embodiment, the ratio between the length of the longest side of the cleaning tank 1 and the length of the shower arm 3 is 1.1. As shown in fig. 2, the shower arm 3 includes a first arm 31, a second arm 32, and a connection portion 33. The first arm 31 and the second arm 32 extend opposite to each other. The first support arm 31 is provided with a plurality of nozzles, wherein the nozzle farthest from the axis of the spray arm 3 is a first nozzle 311. The second arm 32 is also provided with a plurality of nozzles, wherein the nozzle farthest from the axis of the spray arm 3 is the second nozzle 321. The spraying direction of the first nozzle 311 and the perpendicular line from the first nozzle 311 to the rotating shaft of the spray arm 3 are positioned on the same vertical plane, and the included angle between the two is 100 degrees, so that when the first support arm 31 points to the corner, the first nozzle 311 can spray on bowls and chopsticks at the corner; an included angle of 45 degrees exists between the spraying direction of the second nozzle 321 and the vertical plane where the perpendicular line from the second nozzle 321 to the rotating shaft of the spray arm 3 is located, so that the moment applied to the spray arm 3 by the water flow reaction force is realized when the spray arm 3 sprays water. As shown in fig. 3, the connection portion 33 is used to connect the shower base 2. Which is provided with a first jaw 331, a second jaw 332 and a connecting ball 333. The first clamping jaw 331 is formed by extending downwards from the lower surface of the first support arm 31, and a first clamping protrusion 3311 extending towards the rotating shaft of the spray arm 3 is arranged at the bottom end of the first clamping jaw 331; the second claw 332 is formed by extending downwards from the surface of the second support arm 32, and the bottom end of the second claw 332 is provided with a second clamping protrusion 3321 extending towards the rotating shaft of the spray arm 3. The first claw 331 is longer than the second claw 332, and the distance from the first claw 3311 to the rotation axis of the shower arm 3 is longer than the distance from the second claw 3321 to the rotation axis of the shower arm 3. The connection ball 333 extends downward from the lower surface of the center of the shower arm 3 along the rotation axis of the shower arm 3, and a connection water channel 3331 is provided therein. As shown in fig. 6, the shower arm 3 is further provided with a shower water passage penetrating along the first arm 31 and the second arm 32 in the longitudinal direction of the shower arm 3, and the shower water passage communicates with the connecting water passage 3331.

After the connection of the cleaning device 10 in this embodiment is completed, the bowl basket 4 is placed in the cleaning chamber of the cleaning tank 1, and a space is formed between the bottom lower surface of the bowl basket 4 and the upper surface of the bottom of the cleaning tank 1. The spray seat 2 is fixedly connected with the cleaning tank 1, the water outlet end of the spray seat is positioned in the space, the connecting ball 333 of the spray arm 3 is inserted into the rotating cavity 23 of the spray seat 2, spherical connection is formed between the spray seat 2 and the connecting ball 333, and the spray arm 3 swings on a vertical plane by taking the spherical center of the spherical surface as an axis through spherical surface matching, and meanwhile, the rotating requirement of the spray arm 3 can be met, namely, the rotating shaft of the spray arm during rotation always passes through the spherical center of the spherical surface matching. The first clamping protrusion 3311 is located below the first track surface 211, and the second clamping protrusion 3321 is located below the second track surface 221, so that the clamping connection between the spray arm 3 and the spray seat 2 is realized, and the spray arm 3 cannot be separated from the spray seat 2 under the action of water pressure. At this time, the water inlet channel 24, the rotating cavity 23, the connecting water channel 3331 and the spraying water channel are all communicated, so that the spraying seat 2 supplies water for the spraying arm 3. After the connection is completed, the spray arm 3 is always located in the above-mentioned space during the movement.

When water is supplied to the water inlet channel 24 of the shower base 2, the water flows directly against the shower water channels in the first arm 31 and the second arm 32, and are discharged from the respective nozzles. Since the water flow sprayed from the second nozzle 321 has a tangential component, the spray arm 3 rotates around the spray seat 2 as a whole, and at this time, the first catching protrusion 3311 abuts against the first raceway surface 211 and the second catching protrusion 3321 abuts against the second raceway surface 221 under the action of the water pressure, so that the posture of the spray arm 3 on the vertical surface is controlled by the first raceway surface 211 and the second raceway surface 221. In this embodiment, the upper concave section of the first track surface 211 and the lower convex section of the second track surface 221 are set so that when the first clamping protrusion 3311 abuts against the upper concave section of the first track surface 211 and the second clamping protrusion 3321 abuts against the lower convex section of the second track surface 221, the spray arm 3 is horizontal, i.e. the rotation axis of the spray arm 3 is vertical (as shown in fig. 5), so that the situation that the cleaning effect is reduced due to the fact that the sprayed water flow is sputtered to the side wall of the cleaning cavity is avoided. In this embodiment, the lower convex section of the first track surface 211 and the upper concave section of the second track surface 221 are set such that when the first clamping protrusion 3311 abuts against the lower convex section of the first track surface 211 and the second clamping protrusion 3321 abuts against the upper concave section of the second track surface 221, the first arm 31 of the spray arm 3 is inclined downward by 5 °, i.e., the angle between the rotation axis of the spray arm 3 and the plumb line is 5 ° (as shown in fig. 6). Thus, when the first arm 31 is directed to the four corners of the cleaning chamber during the rotation of the spray arm 3 relative to the cleaning tank 1, the state of the spray arm 3 is as shown in fig. 6, and the first arm 31 is inclined downward by 5 °; when the first arm 31 is directed to the four sides of the cleaning chamber, the shower arm 3 is in a state as shown in fig. 5, and the first arm 31 is horizontal. Since the first arm 3 is inclined downward by 5 ° when directed to the four corners of the cleaning chamber, the first nozzle 311 can spray to a longer distance until it sprays onto the bowls and chopsticks in the bowl basket 4, and of course, the first nozzle 311 does not spray onto the sidewall of the cleaning tank 1 due to the setting of the spraying direction of the first nozzle 311 and the setting of the downward inclination limit. Through a lot of experimental tests, when the ratio between the length of the longest side of the cleaning tank and the length of the spray arm 3 is greater than 1.0 and less than 1.3, the included angle between the rotating shaft of the spray arm 3 when the first support arm 31 points to the corner of the cleaning chamber and the rotating shaft of the spray arm 3 when the first support arm 31 points to the side of the cleaning chamber should be less than 8 °, and the included angle between the spraying direction of the first nozzle 311 and the perpendicular line from the first nozzle 311 to the rotating shaft of the spray arm should be greater than 90 ° and less than 106 °. Thus, when the first arm 31 is tilted downward, the first nozzle 311 is not sprayed onto the side wall of the washing tub, but onto the bowls and chopsticks on the bowl basket 4.

As can be seen from the above description, the technical solution of the present application enlarges the cleaning coverage area of the first nozzle 311 when the first arm 31 points to the corner of the cleaning chamber, and achieves the technical effect of cleaning bowls and chopsticks in four corners.

The above description and examples are illustrative of the scope of the application and are not to be construed as limiting the scope of the application.

Claims

1. A cleaning device comprising:

a cleaning tank provided with a square cleaning cavity;

The spray seat is fixed relative to the cleaning tank, and the water outlet end of the spray seat is positioned in the cleaning cavity; and

The spray arm is supplied with water by the spray seat and sprayed into the cleaning cavity, and rotates relative to the cleaning tank under the reaction force of water flow; the spray seat is provided with a first support arm, a second support arm and a connecting part, wherein the first support arm and the second support arm extend in opposite directions;

The method is characterized in that:

the connecting part is provided with a first clamping protrusion and a second clamping protrusion which are respectively positioned below the first support arm and the second support arm; the first clamping protrusion and the second clamping protrusion are slidably clamped on the spray seat in the rotation process of the spray arm so as to prevent the spray arm from being separated from the spray seat; when the first support arm points to all corners of the cleaning cavity, the clamping points of the first clamping protrusion and the spraying seat are lower than the clamping points of the first clamping protrusion and the spraying seat when the first support arm points to the side of the cleaning cavity.

2. A cleaning device as defined in claim 1, wherein: the spraying seat is provided with a first track surface and a second track surface; the first track surface is positioned below the second track surface; the first track surface and the second track surface are downward closed surfaces, and the projection of the first track surface and the second track surface on the horizontal plane is annular; the first track surface and the second track surface are wavy and are opposite in phase after being horizontally unfolded; the parts of the first track surfaces, which point to the corners of the cleaning cavity, are all downward convex; the first clamping protrusion and the second clamping protrusion respectively push against the first track surface and the second track surface to realize clamping connection.

3. A cleaning device as claimed in claim 2, wherein: the spray seat is provided with a first flange and a second flange; the first flange is positioned below the second flange; the lower surface of the first flange and the lower surface of the second flange respectively form a first track surface and a second track surface; the lower surfaces of the first support arm and the second support arm are respectively provided with a first clamping claw and a second clamping claw which extend towards the rotating shaft of the spray arm.

4. A cleaning device according to claim 3, wherein the spray base is provided with an upwardly opening rotary chamber; the rotating cavity is communicated with a water inlet channel of the spray seat; the connecting part is provided with a connecting ball head which extends downwards from the lower surface of the spray arm along the rotation axis of the spray arm, and a connecting water channel communicated with the spray water channel in the spray arm is arranged in the connecting ball head; the connecting water channel is opened at the top end of the connecting ball head; and when the first clamping protrusion and the second clamping protrusion are respectively clamped with the first track surface and the second track surface, the connecting ball head is matched with the spherical surface of the rotating cavity.

5. A cleaning device as defined in claim 1, wherein: when the first support arm points to the edge of the cleaning cavity, the rotating shaft of the spray arm is vertical.

6. A cleaning device as claimed in claim 5, characterized in that the angle between the axis of rotation of the spray arm when the first arm is directed towards the corner of the cleaning chamber and the axis of rotation of the spray arm when the first arm is directed towards the edge of the cleaning chamber is less than 8 ° when the ratio between the length of the longest edge of the cleaning tank and the length of the spray arm is greater than 1.0 and less than 1.3.

7. A cleaning device as claimed in claim 1, wherein the first arm is provided with a first nozzle furthest from the axis of rotation of the spray arm, the direction of the first nozzle being in the same vertical plane as the perpendicular to the axis of rotation of the spray arm, and the angle between the first nozzle and the axis of rotation of the spray arm being obtuse.

8. A cleaning device as defined in claim 7, wherein the included angle is less than 106 ° when the ratio between the length of the longest side of the cleaning tank and the length of the spray arm is greater than 1.0 and less than 1.3.

9. A cleaning device as claimed in claim 1, wherein the second arm is provided with a second nozzle furthest from the axis of rotation of the spray arm, the direction of the second nozzle being at an angle to the vertical plane in which the second nozzle is perpendicular to the axis of rotation of the spray arm.