JP2002276592A - Dish washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that air biting or cavitation is generated when reversely rotating the pump (in the draining operation in usual) to lower the efficiency and that the noise is generated during the operation in a pump unit capable of operating circulation of the washing water and the rinse water stored in a washing tank and operating drainage by only switching rotating direction of a pump driving means in a dish washer. SOLUTION: In an impeller inside of a pump scroll, a blade part is deformed into a swept-back wing efficient to transport the fluid by a water flow applied to the blade when rotating the impeller, or diameter of the impeller is reduced in response to the necessary output so that air stuck and cavitation is hard to be generated in both case of normally and reversely rotating the pump.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller structure and a scroll structure of a centrifugal pump which are mounted on a dishwasher or the like and perform circulation operation of washing water and rinsing water and drainage operation.

[0002]

2. Description of the Related Art A cleaning tank for storing an object to be cleaned as shown in FIG. 5, a water supply means for supplying cleaning water, rinsing water and the like used for cleaning and rinsing into the cleaning tank, and a cleaning tank. Discharge means for discharging water, washing water and rinse water to be sprayed onto tableware, and supply devices such as pumps for pumping the supplied washing water and rinsing water to wash and rinse the objects to be washed. In a dishwasher or the like provided with an injection port, a centrifugal pump is often used as a discharging means for washing water and rinsing water and a pumping device for injecting the dishware.

In this pump, an opening / closing device such as a small valve that opens and closes a valve by a water flow is arranged as in Japanese Patent Application Laid-Open No. 10-295620 as shown in FIG. There is a pump that can perform two functions with a so-called one motor that switches between a washing / rinsing operation and a draining operation, and can save space and cost compared to mounting two pumps.

[0004]

However, the above embodiment has the following problems. In the case of a centrifugal pump that conveys water, retreating wings are often used for impellers in order to suppress separation near the blades during rotation of the impeller and to operate efficiently. In the case of a pump of the type in which the transfer is performed in each case, if the pump is designed as shown in FIG. 6A so as to be a swept wing at the time of normal rotation (FIG. 6B), the blades at the time of reverse rotation (FIG. 6C) A high-efficiency pump without cavitation during normal rotation also bites air and generates cavitation during reverse rotation, as the wing shape of the car becomes a forward wing and there is a problem of sound generation due to air entrainment due to cavitation as a result There is a problem that the pump is easy to perform.

[0005]

In the dishwasher of the present invention, in order to solve the above-mentioned problems, the shape of the impeller blades changes due to a change in the rotation direction of the pump, so that the pump structure is efficient both in normal rotation and in reverse rotation. The impeller is configured so that

[0006]

FIG. 1 shows an embodiment of the first embodiment. Figure 1
(A) shows the structure of the pump in a stationary state. (B),
(C) shows the state inside the scroll at the time of forward rotation of the pump and at the time of reverse rotation, respectively. As shown in FIG. 1A, the pump of the present invention covers the impeller 2 and a driving means 3 such as a motor for rotating the impeller 2, the impeller 2, and a fluid suction port 4 and a first drain. It comprises a casing 6 provided with an outlet 5, a second outlet 7, and an opening / closing device 8 for opening and closing a flow path to the second outlet. Is composed of an elastic body that is deformed by a water flow.

As shown in FIG. 1B, when the impeller of the pump is rotated forward 10, fluid is sucked from the suction port 4, and a water flow is generated in the scroll in the same direction 11 as the impeller. Then, a reaction force 12 due to the water flow acts on the wing in the opposite direction. As a result, the wings made of the elastic body become swept wings due to the deformation due to the water flow, and the fluid sucked from the suction port 4 is discharged to the first wing.
Can be smoothly discharged from the discharge port of the wing without peeling near the wing which is likely to occur at the time of the forward wing or the like. Figure 1
As shown in (c), when the impeller of the pump is rotated in the reverse direction, the rotation direction of the impeller becomes reverse 13, and a reaction force 15 is generated on the blade in a direction opposite to the water flow direction 14 accompanying the rotation. result,
The wings made of an elastic body are swept back wings as in the case of the forward rotation, and the fluid sucked from the suction port 4 in this case opens and closes the switchgear 8 due to the water flow.
From the wings without any separation near the wings.

Further, the second embodiment shown in FIG. 2 has wings similarly formed of an elastic body. However, when the rotor is rotated forward as shown in FIG. The outer diameter of the impeller itself changes due to the deformation. In this example, the outer diameter 16 of the impeller during the reverse rotation is smaller than the outer diameter 17 during the forward rotation. In addition, the impeller whose outer diameter changes due to such a difference in the rotation direction,
The surface of the wing as shown in (c) can be realized by bonding two materials having different hardness. By doing so, the AC which is often used as a pump driving means is
In the case of a condenser motor or the like, the number of revolutions decreases because the water flow resistance of the blades decreases. That can slow down the output of the pump, it is possible to operate the pump at the output of the only required at the time of drainage stroke at the time of reversal.

The third embodiment has a two-stage impeller configuration. One of the impellers has a smaller diameter during reverse rotation, and the other has a smaller diameter during normal rotation. I have. In the example shown in FIG. 3, one inlet, two impellers 22 and 23, and two outlets 24 and 25 are provided. The impeller 23 is designed so that the diameter of the impeller 23 during the forward rotation of the pump and the diameter of the impeller 22 during the reverse rotation are reduced by the flow of water. With such a configuration, the fluid sucked in from the suction port 4 is discharged from the discharge port 24 impeller during normal rotation and from the discharge port 25 during reverse rotation. At this time, due to the nature of the centrifugal pump, a slight discharge of fluid is also seen from the discharge port 25 at the time of normal rotation and the discharge port 24 at the time of reverse rotation. Elimination or minimization of emissions by using a return bypass to the primary side of the pump installed in the discharge path downstream of the discharge port as well as avoiding discharge by setting up the path. Can be. Further, as an application example described above, the shape of the blade itself is greatly changed by being completely housed in the shaft side of the impeller only when the pump rotates in a certain rotation direction, or by making the blade a multi-node link mechanism. It is also possible. In the present embodiment, the impeller has a two-stage configuration. However, as a multi-stage configuration of three or more stages, some of the impellers have a small diameter at the time of reverse rotation, and some have a small diameter at the time of normal rotation. It is possible.

In the fourth embodiment shown in FIG. 4, the root of the wing 26 has a hinge structure 27, and when the contact direction of the wing changes due to the water flow due to the change of the rotation direction, the strength of the water flow, that is, the rotation Regardless of speed, fluid viscosity, etc.
The shape of the wing is always determined at a certain contact angle. It should be noted that a stopper may be provided to regulate the contact angle, or an elastic wing may be used in the present structure.

[0011]

As is clear from the above embodiment, the following effects can be obtained by the present invention. By controlling the rotation direction of only one pump, both the circulating operation and draining operation of water (or cleaning water / sewage) in the cleaning tank are performed while avoiding inefficient conditions such as generation of noise due to air entrainment due to cavitation. can do.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a dishwasher pump structure of the present invention.

FIG. 2 is a second embodiment of the dishwasher pump structure of the present invention.

FIG. 3 is a third embodiment of the dishwasher pump structure of the present invention.

FIG. 4 is a fourth embodiment of the dishwasher pump structure of the present invention.

FIG. 5 is a peripheral view of a pump unit in a conventional dishwasher.

FIG. 6 shows a pump unit in a conventional dishwasher.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 pump 2 impeller 3 pump driving means 4 suction port 5 first discharge port 6 scroll 7 second discharge port 8 opening and closing device 9 blade 10 rotation direction of pump at normal rotation 11 flow direction of water in scroll at normal rotation of pump 12 Direction of reaction force applied to blades during forward rotation of pump 13 Rotational direction during reverse rotation of pump 14 Direction of flowing water in scroll during reverse rotation of pump 15 Direction of reaction force applied to blades during reverse rotation of pump 16 Reversed pump in second embodiment Shape of impeller at the time of rotation 17 Outer diameter of impeller at the time of forward rotation of pump 18 in the second embodiment 18 One surface of blade (configured of material harder than 19) 19 The other surface of blade (18) 20 Blade shape at the time of forward rotation of the pump in the second embodiment 21 Blade shape at the time of reverse rotation of the pump in the second embodiment 22 First example of the third embodiment Impeller 23 second impeller in the third embodiment 24 first discharge port in the third embodiment 25 second discharge port in the third embodiment 26 wing in the fourth embodiment 27 fourth Structure which is the root of the wing in the embodiment of the present invention

Claims (10)

[Claims] 1. A so-called spiral pump comprising: an impeller; a driving means such as a motor for rotating the impeller; and a casing which covers the impeller and has a fluid inlet and an outlet. A type in which the first and second discharge ports are provided, and an opening / closing device is provided for opening and closing the flow path to the second discharge port by utilizing the power of the water flow in the scroll flow path generated by the rotation direction of the pump. A pump device characterized in that the blade shape of the impeller changes according to the rotation direction of the pump. 2. A washing tank for storing an object to be washed, water supply means for supplying washing water, rinsing water and the like used for washing and rinsing into the washing tank, and discharging for discharging from the washing tank. Means, and a supply device such as a pump for pumping up the supplied washing water / rinsing water for washing / rinsing the object to be washed, and a jet port for ejecting washing water / rinsing water to be sprayed on tableware are provided. A dishwasher, wherein the pump according to claim 1 is mounted in a dishwasher of a type in which a discharge means and a washing water / rinsing water supply device are integrated. 3. The dishwasher according to claim 2, wherein the wing shape is deformed so as to be always a swept wing irrespective of the rotation direction. 4. The apparatus according to claim 2, wherein when the rotation direction of the pump is changed, the blade diameter of the impeller is reduced, and as a result, the work as the fluid conveyance is reduced. A dishwasher according to any one of claims 1 to 3. 5. The dishwasher according to claim 4, further comprising a plurality of impellers having different rotation directions for changing the blade diameter or the like. 6. The dishwasher according to claim 5, wherein when the rotation direction of the pump is changed, the blades of some impellers are completely stored. 7. The dishwasher according to claim 2, wherein the impeller blades are provided with a pump made of an elastic body so as to be deformed by a water flow and a water pressure applied to the blades when the pump rotates. 8. A pump having a structure in which a spring or an elastic body is provided at the root of the impeller so that the impeller blades change an incident angle and an outlet angle depending on a water flow and a water pressure received by the blade when the pump rotates. A dishwasher according to claim 2. 9. The dishwasher according to claim 2, wherein the wing root of the impeller has a hinge structure. 10. The dishwasher according to claim 2, wherein a stopper mechanism is provided so as to stop at a predetermined angle when the impeller blade shape is deformed.