JPH1150997A - Small pump device and electric water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small pump device capable of being incorporated without affecting the size and the height of the whole product and capable of moving liquid in two directions. SOLUTION: A communication pipe communicated with the lower part and of a water storage tank and the outside is formed of a rising part composed of a screw pump part 12, a straight pipe 13 and a swirl chamber 14 and a discharging part, and an electrically-driven pump mechanism 16 for pumping liquid is arranged on the way of the communication pipe. The electrically-driven pump mechanism 16 is constituted of a centrifugal pump part provided with an impeller 19 arranged in the swirl chamber 14, and the screw pump part 12 in which a screw 17 is arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small pump device for sucking and discharging a liquid contained in a tank by an electric mechanism and an electric kettle pot device.

[0002]

2. Description of the Related Art Conventionally, various small pump devices using a motor drive source have been proposed as hot water supply devices for electric water heaters and the like, one example of which will be described with reference to FIGS.

In the electric kettle 61, a water storage tank 63 for placing a liquid in an outer frame body 62 is arranged. Outside the water storage tank 63, the inside of the water storage tank 63 and the outside of the outer frame body 62 are arranged. A communication pipe 64 for communication is provided. The liquid such as water put in the water storage tank 63 can be heated by an electric heating device (not shown).

One end of the communication pipe 64 is connected to the water storage tank 6.
3 is connected to a suction port 65 provided at a lower end portion, and the other end is connected to a discharge port 66 formed above the outer frame body 62. Thereby, the water storage tank 63 and the outside of the outer frame body 62 are communicated by the communication pipe 64.
In the vicinity of the suction port 65 of the communication pipe 64, an electric small pump device 67 for pumping liquid is provided.

[0005] The electric kettle 61 configured as described above rotates the impeller (not shown) of the small pump device 67 to generate a negative pressure at the center of rotation of the impeller, thereby causing the liquid in the water storage tank 63 to rotate the impeller. After being sucked into the center, it is sent out toward the discharge port 66. Note that the small pump device 67 is disposed together with the control board 68 in a space below the bottom of the water storage tank 63.

In the above-described small pump device 67, when pumping the liquid boiling in the water storage tank 63, there is often a problem that a cavitation phenomenon occurs. In addition, the cavitation phenomenon is that when a liquid whose temperature has risen to near the boiling point is pumped around the impeller, the boiling point of the liquid decreases due to the negative pressure around the impeller, and the liquid evaporates at a stroke around the impeller and gas is generated. This refers to a phenomenon in which bubbles that are filled or generated when the liquid boils expand at a stretch around the impeller, and the chamber in which the impeller is disposed is filled with a gas such as air. If such a cavitation phenomenon occurs when pumping boiling water and gas concentrates on the rotation center of the impeller, the small pump device 67 runs idle and cannot pump water.

As a small pump device for preventing such a cavitation phenomenon, for example, JP-A-7-2
A small pump device 69 having a structure as described in Japanese Patent No. 17600 has been proposed (see FIG. 17). This small pump device 69 is provided with the electric kettle 6 described above.
1, that is, at the same position as the small pump device 67. The small pump device 69 includes a motor 71 having a rotating shaft 70,
, A vortex chamber 73 for accommodating the impeller 72, and a screw blade 74 fixed to the tip of the rotating shaft 70. That is, the impeller 72 and the screw blade 74 are coaxially fixed to the rotating shaft 70 of the motor 71.

The vortex chamber 73 is formed as a cylindrical space centered on the rotation center of the impeller 72, and has a suction port 75.
And a discharge port (not shown). The suction port 75 is connected to the water storage tank 63 by a communication pipe 64. In addition, a screw blade 74 fixed to the rotating shaft 70 extends into the suction port 75. The discharge port communicates with the discharge port 66 through a communication pipe 64.

In the small pump device 69 configured as described above, the impeller 72 rotates when the motor 71 starts and the rotating shaft 70 rotates. Then, the small pump device 69 generates a negative pressure near the rotation center of the impeller 72, and sucks the liquid on the water storage tank 63 side into the vortex chamber 73. At this time, the screw blade 74 also rotates integrally with the impeller 72 so as to suppress the cavitation phenomenon generated at the rotation center of the impeller 72.
That is, the rotation of the screw blade 74 positively sends the liquid on the water storage tank 63 side to the rotation center of the impeller 72, thereby preventing the rotation center of the impeller 72 from being filled with air and running idle.

[0010] As a pump device used on land, not an electric kettle pot, a pump device provided with two pump portions for quickly sucking water is known (Japanese Utility Model Application Laid-Open No. Sho 61-66693). Gazette). This pump device 80 is, as shown in FIG.
The rotation of one impeller 82 is transmitted to an axial impeller 84 via a flexible wire 83. The flexible wire 83 transmits a driving force via the coupling converters 85 and 86.

In the pump device 80, when the operation is started, the water filling the lower end of the suction pipe 87 is filled with water.
7 and enters the casing of the upper spiral pump 81. Thereafter, the water is sucked and discharged by the upper spiral pump 81.

[0012]

However, in the electric kettle 61 described above, the small pump device 67,
Since 69 is provided between the bottom of the water storage tank 63 and the bottom of the outer frame 62, a space for installing the small pump devices 67 and 69 is provided between the bottom of the water storage tank 63 and the bottom of the outer frame 62. This necessitates a problem that the height H between the bottoms is increased and the height of the entire product is increased.

Further, since the impeller housing portions of the small pump devices 67 and 69 are installed at the lowest position of the communication pipe 64, deposits (calcium hydroxide) and the like from water are easily accumulated. Moreover, in the conventional small pump devices 67 and 69, no special measures are taken to prevent the deposits from being deposited, or no configuration is provided to remove the deposited deposits. In such a situation, if deposits accumulate around the impeller, the deposits hinder rotation of the impeller, and there is a danger that the motor will be locked.

Further, in the small pump device 69, a screw blade 74 is disposed coaxially in the vicinity of the impeller 72 in order to prevent the cavitation phenomenon. However, the screw blade 74 adversely interferes with the suction operation of the impeller 72. . Therefore, in the small pump device 69, the screw blade 74 itself is provided with a large pumping ability by bringing the screw blade 74 into close contact with the inner wall of the suction port 75, so that the pump performance of the small pump device 69 as a whole is maintained. . However, in order for the outer diameter of the screw blade 74 to be in close contact with the inner wall of the suction port 75, a high degree of processing accuracy is required, and there is a problem that mass productivity as a product is lacking. In addition, when the outer diameter of the screw blade 74 is brought into close contact with the inner wall of the suction port 75, there is a problem that deposits are caught in that portion and the motor is locked.

When the water in the water storage tank 63 is discharged from the discharge port 66 after being heated and boiled by an electric heating device, the water in the communication pipe 64 is not heated. Has a problem that it gets warm.

Further, the pump device 80 disclosed in Japanese Utility Model Laid-Open Publication No. Sho 61-66693 uses the flexible wire 83, so that the coupling converters 85 and 86 are required and the device becomes large. In particular, the coupling conversion units 85, 8
The mounting portion of 6 protrudes outside the suction pipe 87, which is unsightly and space-wise. Further, the pump device 8
0 indicates that only the pumping is considered.
Even if the water in the inside is caused to flow in the reverse direction, the driving force of the axial flow impeller 84 in the reverse direction is not sufficient with respect to the suction force of the spiral pump 81, and the water cannot move in the reverse direction. It has become. Also, in the case of the axial impeller 84, when it is actually applied, the lift force cannot be sufficiently obtained. Therefore, in particular, in the case of a miniaturized small pump device, it is often the case that water cannot be raised to the swirl pump 81.

According to the present invention, in consideration of the above-mentioned problems, a small pump device capable of driving liquid in both directions without affecting the size and height of the entire product when assembled into a product such as an electric kettle. And an electric kettle pot device. Further, the present invention provides a small pump device and an electric kettle pot device having a structure in which troubles such as a motor lock caused by deposition of deposits, particularly, calcium hydroxide and the like, coming out of water into a water storage tank are less likely to occur. The purpose is to do. Further, the present invention provides a small pump device and an electric kettle device that can suppress the cavitation phenomenon with a configuration that does not require high processing accuracy and that can solve the problem of the first cup becoming tepid. The purpose is to:

[0018]

In order to achieve the object, a small-sized pump device according to the first aspect of the present invention has a water storage tank for storing liquid, a rising portion communicating with a lower portion of the water storage tank, and a rising portion connected to the rising portion. In a small pump device provided with a communication pipe having a discharge unit that communicates and discharging the liquid in the water storage tank to the outside, and an electric pump mechanism that is disposed in the middle of the communication pipe and pumps up the liquid, Along with disposing a centrifugal pump unit having an impeller that becomes a part of the electric pump mechanism above the rising portion,
A screw pump section having a screw that becomes a part of the electric pump mechanism is disposed below the rising section.

Further, the small pump device according to claim 2 is
In addition to the first aspect of the present invention, a bidirectional rotating motor serving as a drive source of the electric pump mechanism is disposed above the outer frame, and the impeller and the screw rotate integrally with the output shaft of the motor. It is installed coaxially with the axis.

Further, the small pump device according to the third aspect of the present invention, in addition to the first or the second aspect of the present invention, further comprises a suction portion above the rising portion for sucking the liquid on the water storage tank side,
A vortex chamber having a discharge section for discharging the liquid sucked from the suction section toward the discharge port and having an impeller disposed therein, and the suction section of the vortex chamber being displaced from the rotation center of the impeller Formed at the location. Further, in the small-sized pump device according to the fourth aspect, in addition to the invention according to the third aspect, in the vicinity of the suction portion, the liquid is easily sucked into the vortex chamber from the suction portion when the impeller is rotating forward and when the impeller is rotated reversely. A slope portion is provided for facilitating the backflow of the liquid in the vortex chamber from the suction portion.

In view of the above object, in the electric kettle pot device according to the fifth aspect, a water storage tank for storing a liquid inside the outer frame body and an electric heating device for warming the liquid in the water storage tank are provided. And a communication pipe for discharging the liquid in the water storage tank to the outside of the outer frame body, the communication pipe having a rising portion communicating with the lower portion of the water storage tank and a discharge portion communicating with the rising portion and communicating with the outside of the outer frame body. And an electric kettle device provided with a small pump device provided with an electric pump mechanism for pumping a liquid, which is disposed at an intermediate portion of the communication tube, wherein at least one is provided above and below the rising portion of the communication tube. A pumping member is arranged.

Further, in the electric kettle pot device according to the sixth aspect, in addition to the invention according to the fifth aspect, the rising portion is disposed between the water storage tank and the outer frame body, and the rising portion of the plurality of pumping members is provided. The upper part of the unit is constituted by a centrifugal pump having an impeller, and the lower part is constituted by a screw pump having a screw.

The small pump device according to the present invention has a water storage tank, a communication pipe, and an electric pump mechanism. And without disposing the pump mechanism at the bottom of the water storage tank,
A centrifugal pump unit having an impeller is arranged above the rising portion of the communication pipe, and a screw pump unit having a screw is arranged below. For this reason, the upper centrifugal pump section can be made smaller, and the upper communication pipe portion becomes a small space. In addition, since the lower screw is inserted into the communication pipe, the lower space loss hardly occurs. As a result, the influence on the height dimension of the product using the small-sized pump device is reduced, and a small-sized pump device capable of giving design freedom in design and size can be obtained.

Further, since the screw pump section is disposed below, when the electric pump mechanism operates, the water in the communication pipe always rises or flows backward to the water storage tank side. . That is, bidirectional movement of the liquid becomes possible. In addition, since the rotating portion of the impeller is disposed above, it is difficult for deposits and the like from water to accumulate, so that a small pump device that prevents problems such as motor lock and the like is provided.

Further, since the impeller and the screw are arranged apart from each other, the screw prevents the cavitation phenomenon without hindering the suction operation of the impeller. Therefore, the suction force of the centrifugal pump section having the impeller is sufficient, and as a result, the screw pump section only needs to have a pump performance enough to supply priming water for preventing the cavitation phenomenon to the impeller. Become. Therefore, the screw of the screw pump does not need to have such a shape as to be in close contact with the inner wall of the communication pipe, so that it is not necessary to increase the precision of processing the parts, and it is possible to provide a small-sized pump device with high mass productivity.

It is preferable that the screw and the impeller are mounted on a shaft that rotates integrally with the output shaft of the bidirectional rotary motor, because the structure is simplified and the performance as a small pump device is improved. Moreover, the cold water in the communication pipe can be returned to the hot water side once, and the hot water can be discharged from the first cup.
Further, in a cleaning mode for cleaning the inside of the apparatus, a precipitate or the like deposited in the communication pipe is stirred by the liquid by back-flowing the liquid in the communication pipe, thereby enabling cleaning. Further, when the suction portion of the vortex chamber storing the impeller is formed at a position shifted from the rotation center of the impeller, the liquid easily flows backward when rotating in the reverse rotation direction.

Further, if a slope portion is provided around the suction portion so as to easily suck the liquid from the suction portion when the impeller rotates forward and to make the liquid flow backward from the suction portion when the impeller rotates in the reverse direction. The pump performance during rotation can be increased, and the liquid can be smoothly moved in the reverse direction during reverse rotation.

Further, the electric kettle pot device of the present invention has a water storage tank, a communication pipe, and an electric pump mechanism. Then, the pumping mechanism is not arranged at the bottom of the water storage tank, and the water pumping members are arranged one by one above and below the rising portion of the communication pipe arranged outside the water storage tank. For this reason, the pump mechanism does not significantly affect the overall dimension in the height direction, and the design and the size can be given a degree of freedom in design. That is, since the pumping member is arranged in the communication pipe and the liquid is pumped up by the cooperative action of the two pumping members, each pumping member can be downsized, and the pumping members can be reduced to the minimum required between the water storage tank and the outer frame. In the space.

If the impeller is arranged above the rising portion of the communication pipe arranged outside the water storage tank and the screw is arranged below, the liquid can be moved in both directions and various functions can be provided. Can be done. For example, reverse rotation of the pump makes it difficult for deposits and the like coming out of water to accumulate, thereby preventing problems such as motor lock, which is preferable. Further, when the impeller and the screw are arranged apart from each other, the screw prevents the cavitation phenomenon without impeding the suction operation of the impeller. For this reason, the suction force of the impeller becomes sufficient, and as a result, the screw pump only needs to have a pump performance enough to supply priming water for preventing the cavitation phenomenon to the impeller.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A small pump device and an electric kettle device according to an embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. In addition, the small pump device 1
Is described as being incorporated in the electric kettle pot device 2.

As shown in FIG. 1, the electric kettle pot device 2 accommodates a water storage tank 4 in a substantially cylindrical outer frame body 3 having a bottom 3a at one end, and an outer frame on the water storage tank 4. A lid 5 is attached to the opening of the body 3 so as to be openable and closable. The upper end periphery of the water storage tank 4 is a bent portion 4 a formed to be bent outward, and the bent portion 4 a is formed by a shoulder 6 a of a shoulder portion 6 formed inside the outer frame 3.
, The water storage tank 4 is supported inside the outer frame 3.

In the center of the upper front part of the outer frame 3,
A beak portion 7 is provided so as to protrude outward, and a discharge port portion 8 for discharging the liquid sent from the water storage tank 4 is provided on a lower surface of the beak portion 7.
Are formed. Further, a water level display window 9 is provided below the beak portion 7 on the outer peripheral surface of the outer frame body 3 to know a standard of the amount of liquid in the water storage tank 4.

Inside the outer frame 3 and outside the water storage tank 4,
A communication pipe 10 for discharging the liquid in the water storage tank 4 to the outside of the outer frame 3 is arranged. This communication pipe 10
It comprises a suction part 11, a screw pump part 12, a straight pipe 13, a vortex chamber 14, and a discharge part 15. The screw pump section 12, the straight pipe 13, and the vortex chamber 14 constitute a rising section.
As shown in FIG. 2, the screw pump section 12 is formed of a cylindrical space that stores a screw 17 that is a part of the electric pump mechanism 16, and is connected to a lower end of the straight pipe 13. . 2, the vortex chamber 14 is formed by a part of a case body 18 disposed above the straight pipe 13, and is disposed above the straight pipe 13. The vortex chamber 14 is a cylindrical space for storing the impeller 19 that is a part of the electric pump mechanism 16. The centrifugal pump section is formed by the vortex chamber 14 and the impeller 19 and the like.

The straight pipe 13 of the communication pipe 10
A reinforcing plate 20 for reinforcing the straight pipe 13 as shown in FIG.
This reinforcing plate 20, as shown in FIGS. 2, 3 and 4,
The four screw holes 20b on one end 20a are aligned with the four screw holes 18aa formed in the fixing portion 18a outside the vortex chamber 14 and then fixed with screws, and the four screw holes 20d on the other end 20c are fixed in the pump chamber. After being fitted to the four screw holes 23aa formed in the fixing portion 23 on the outer side of 12, the screw is fixed with screws.

As shown in FIGS. 1 and 5, the suction portion 11 has a substantially U-shaped pipe communicating with the inside of the water storage tank 4 through a communication port 21 formed in a peripheral portion of the bottom surface of the water storage tank 4. It is formed of a member.

As shown in FIG. 5, the screw pump section 12 connects the suction section 11 and the straight pipe 13 at a right angle, and is formed of a substantially cylindrical case body. At the lower end of the screw pump section 12, a drawing port 22 connected to the suction section 11 is provided.
As shown in FIGS. 2, 4, and 5, a fixing portion 23 for fixing one end of the reinforcing plate 20 is formed outside the screw pump portion 12. The reinforcing plate 20
The other end of the fixing part 1 formed outside the case body 18
8a. A waterproof cap 24 is fitted into the upper edge of the screw pump section 12. The waterproof cap 24 is formed of a rubber device conforming to the Food Sanitation Act and the standard for food additives, and makes the connection between the screw pump section 12 and the straight pipe 13 strong.

As shown in FIG. 2, the straight pipe 13 is formed of a cylindrical member having a lower end connected to the upper end portion of the screw pump section 12 and an upper end connected to the vortex chamber 14. The straight pipe 13 is formed of a transparent member such as transparent glass, and is provided with a water level display window 9.
The liquid level of the liquid in the straight pipe 13 is more visible. And this straight pipe 13
The remaining amount of the liquid in the water storage tank 4 can be estimated by checking the water level in the inside. The connecting portion between the straight pipe 13 and the vortex chamber 14 is provided with a waterproof cap 25.
Is fitted. Like the waterproof cap 24, the waterproof cap 25 is formed of a rubber device conforming to the Food Sanitation Law and the standard for food additives, and has a strong connection between the straight pipe 13 and the vortex chamber 14. To prevent water leakage from the connecting part.

The vortex chamber 14 of the centrifugal pump part is a part of the electric pump mechanism 16. That is, as shown in FIG. 2, the electric pump mechanism 16 includes a lower screw pump section 12, a straight pipe 13, and an upper vortex chamber 14.
And a centrifugal pump section comprising an impeller 19 and the like, and a motor 26
It is mainly composed of And its components are:
Mainly, a case body 18 disposed above the straight pipe 13, a motor 26 supported by the case body 18, and a shaft 27 that is rotated by the rotational driving force of the motor 26.
And the impeller 19 and the screw 17 fixed to the shaft 27. The centrifugal pump unit having the impeller 19 and the screw pump unit 12 having the screw 17 are water pumping members that suck liquid by rotating. And the vortex chamber 14 is the case body 1
8 and is connected to the discharge unit 15.
The vortex chamber 14 will be described later in detail.

The discharge section 15 is connected to the vortex chamber 14 and extends horizontally, and the discharge pipe 2 for discharging the liquid sent from the water supply pipe 28 to the outside of the outer frame 3.
9 and a safety valve device 30 provided between the water supply pipe 28 and the discharge pipe 29. The ejection unit 1
5 is arranged so as to fit between the beak 7 and the shoulder 6. The distal end of the discharge pipe 29 is connected to the discharge port 8, and the discharge port 8 is provided with a discharge opening 32 provided in an under cover 31 formed in the beak 7 as shown in FIG. Is facing.

The safety valve device 30 comprises a fall safety valve 34 housed in a safety valve case 33 and a tilt safety valve 35. The fall safety valve 34 closes the water pipe 28 when the electric kettle pot device 2 falls. When the electric kettle pot device 2 is tilted backward, the safety valve 35 at the time of tilting is used to feed the water pipe 28.
Is closed.

As shown in FIG. 5, an electric heating device 36 is provided below the water storage tank 4. This electric heating device 36
Is operated, the liquid in the water storage tank 4 is heated. In addition, a communication port 21 that communicates with the communication pipe 10 is provided in a peripheral portion of the bottom surface of the water storage tank 4. Thus, the water storage tank 4 communicates with the outside of the outer frame 3 via the communication pipe 10.

As shown in FIG. 2, a case body 18 disposed above the straight pipe 13 of the communication pipe 10 is provided.
Is separated into a motor housing 37 and a vortex chamber 14.
That is, as shown in FIG. 6, the case body 18 is formed of a substantially cylindrical member, and an engaging portion 39 is formed on the upper edge. As shown in FIG. 2, the engaging portion 39 engages a middle case 38 formed in a cup shape. Then, the middle case 38 is inserted from the upper side of the case body 18, and the projection 40 formed on the upper end portion of the middle case 38 is engaged with the engaging portion 39, thereby forming a substantially upper half of the case body 18. Is fitted with the middle case 38. As a result, the case body 18 is placed in the upper room, that is, the motor housing 37 that supports the motor 26.
And the lower chamber, that is, the vortex chamber 14 for storing the impeller 19.

Inside the middle case 38, there is formed a step portion 42 which engages with a resin plate 41 fixed to the plane portion of the motor 26 and supports the motor 26. Motor 2
6 is a state in which the plate 41 comes into contact with the stepped portion 42 when it is put into the middle case 38, so that it only enters the middle part of the middle case 38, and approximately half projects upward from the middle case 38. It is fitted with. A portion of the motor 26 protruding upward is covered with a motor cap 44 for protecting the motor terminal 43.

The outer frame 3 above the motor 26 has
As shown in FIG. 7, a closing lid 45 is provided, and a pair of movable contacts 47 connected to a lead wire 46 are attached to the closing lid 45. The movable contact 47 contacts the motor terminal 43 formed on the upper end surface of the motor 26 when the closing cover 45 is closed. The lead wire 46 is connected to a control circuit board (not shown), and the motor 26 is driven by a signal from the control circuit board when the ejection button is operated from the outside.

A motor output shaft 48 extends rotatably from the center of the surface of the motor 26 on which the plate 41 is fixed. The tip of the motor output shaft 48 enters the central portion 38 a of the middle case 38. A doughnut-shaped induction magnet 49 for guiding the impeller 19 is fixed to a middle portion of the motor output shaft 48 via a magnet holding member 49a. In this embodiment, a dry axial anisotropic ferrite magnet is used as the induction magnet 49, but another magnet such as a rare earth magnet may be used.

A shaft fixing portion 50 is formed on the bottom of the middle case 38 so as to protrude further below the bottom, ie, into the vortex chamber 14. A fixed shaft 51 that rotatably supports the impeller 19 stored in the vortex chamber 14 is fitted and fixed to the shaft fixed portion 50.

The vortex chamber 14 is a space for rotatably storing the impeller 19, as shown in FIG. 8, a suction part 52 for sucking the liquid from the water storage tank 4 side, and a water supply pipe 28 for the discharge part 15. And a discharge unit 53 that is connected to the discharge port and discharges the sucked liquid to the discharge port 8 side. FIG.
As shown in the figure, the bottom of the vortex chamber 14 is formed at a position deviated from the rotation center of the impeller 19. Further, in the vicinity of the suction portion 52, as shown in FIG. 9, a slope portion 54 formed of a concave portion gradually deepening from a part of the bottom portion of the vortex chamber 14 toward the suction portion 52 is provided. . In addition, the vortex chamber 14 is located on the opposite side of the slope 54 and the suction portion 52.
Projection 1 formed so as to project inward from the inner peripheral wall of
8b are formed.

With such a configuration, the suction force of the liquid in the vortex chamber 14 varies depending on the rotation direction of the impeller 19. That is, when the impeller 19 rotates in the direction indicated by the arrow A (positive direction) in FIG. 6, the liquid on the straight pipe 13 side is sucked from the suction portion 52 while the suction capacity is slightly weakened. It becomes easy to be sucked into the vortex chamber 14 through the vortex chamber 54.

Conversely, the impeller 19 is moved in the direction indicated by the arrow B in FIG.
When rotated in the direction (reverse direction), the suction portion 52 is shifted from the center, so that the suction force is reduced and the protrusion 18
The gap between the case body 18 and the impeller 19 is narrowed by b, so that it is difficult for the liquid to move to the discharge port 8 side. In addition, since the inclined portion 54 comes in front of the rotation of the suction portion 52, the liquid in the vortex chamber 14 easily flows back along the inclined portion 54 toward the straight pipe 13. As a result, when the impeller 19 is rotated in the reverse direction, the suction capacity of the impeller 19 decreases, and the liquid easily flows backward due to the rotational force of the screw 17.

The impeller 19 is made of a resin magnetic material such as PPS, and includes a shaft 55 and a plurality of blades 56 as shown in FIG. Is provided with a fitting hole 57 which is rotatable with respect to. A groove 57 a is formed at one place on the inner peripheral surface of the fitting hole 57, and a projection provided on the outer periphery of the bearing 60 is fitted, so that the bearing 60 is fitted into the fitting hole 57. . A through hole 57b penetrating the lower D-shaped fitting hole 55a is formed on the lower surface of the fitting hole 57. As shown in FIGS. 2 and 7, the bearing 60 serves to rotatably support the impeller 19 with respect to the fixed shaft 51, and has a cup shape having a hemispherical projection 60a on the bottom surface. Is formed.

The bearing 60 is formed as described above. However, as shown in FIG. 11, the bearing 60 'is formed in a cup shape having a tapered side surface gradually expanding from the bottom surface X toward the inlet Y. It is good. When this bearing 60 'is employed, even if the rotation center of the impeller 19 and the shaft center of the fixed shaft 51 are assembled in a state where the shaft slightly shifts, the fixed shaft 51 may damage the inside of the bearing 60'. The risk of prying is reduced.

The plurality of blades 56 of the impeller 19
Are magnetized in quadrupole planes at every 90 ° for magnetic induction by an induction magnet 49 arranged in the middle case 38. That is, when the motor 26 is driven and the motor output shaft 48 rotates, it is magnetically guided by the induction magnet 49 and rotates in the vortex chamber 14. In addition,
When the impeller 19 rotates, a negative pressure is generated at the rotation center of the impeller 19, and an action of sucking air, liquid, and the like in the straight pipe 13 around the rotation center works.

The lower end of the shaft portion 55 of the impeller 19 is provided with an upper end 27a having a D-shaped cross section.
It is fitted and fixed in the mold fitting hole 55a. The shaft 27 is disposed inside the straight pipe 13, and the lower end is a screw 17 disposed below the straight pipe 13.
It is fixed to. Therefore, the impeller 19 and the screw 17 are fixed at a coaxially separated position.

The screw 17 is made of a resin material such as PPS. The screw 17 is formed of a lead screw formed in a plurality of spiral shapes, and is stored in the screw pump unit 12.
Therefore, when the shaft 27 rotates in the forward direction, the screw 17 moves the liquid on the suction part 11 side to the vortex chamber 14 side, and when the shaft 27 rotates in the reverse direction,
The liquid on the vortex chamber 14 side is caused to flow back to the suction section 11 side. Note that the outer diameter of the screw 17 is not precisely configured with respect to the inner wall of the screw pump section 12, and therefore the pump performance is weaker than that of the impeller 19. by this,
The screw pump section 12 can be easily assembled and has high mass productivity.

The screw 17 of this embodiment is a screw formed continuously for 5 rotations (= 1,800 °), but may be shaped to connect screws of one pitch of 360 ° or less. In addition, the pitch is about 8.0 mm, the pressure angle is 25 °, and the lead angle is 11.9, but other values may be used. Furthermore, the gap between the outer peripheral portion of the screw 17 and the inner peripheral surface of the straight pipe 13 is set to 0.7 to 0.8 mm.
~ 1.2 mm is preferred. Further, the screw 17
It is also possible to use one for 360 ° or another number such as 1080 ° (= 3 rotations). Even with a small number, sufficient pumping power can be secured. However, the effect of the backflow becomes weaker with lower numbers. Therefore, the number of screws is 1
5 is preferable, and two or three are most preferable.

As described above, the screw pump section 12
The pump performance is lower than that of the centrifugal pump section having the impeller 19. As its role, it has two functions of causing the liquid to flow backward at the time of forward rotation, and at the time of reverse rotation for supplying the liquid to at least the portion of the impeller 19. In addition, the centrifugal pump part having the impeller 19
The pump performance is high, and once the liquid
4, the liquid can be reliably discharged in a large amount. However, the center of rotation of the vortex chamber 14 has a negative pressure, and when pumping boiling water, hot water having a temperature close to the boiling point evaporates or bubbles generated when the hot water evaporates expand. And the cavitation phenomenon occurs.

That is, even if cavitation occurs in the centrifugal pump section during the forward rotation, the screw 17 reliably supplies hot water to the rotation center of the impeller 19 so as to prevent cavitation. At the time of reverse rotation, screw 1
7 reverses the liquid in the vortex chamber 14 and the communication pipe 10 and returns the liquid to the water storage tank 4. In particular, in this embodiment, at the time of reverse rotation,
Since the suction effect of the centrifugal pump section is weakened, the return amount increases.

It should be noted that the screw 17 is provided in FIG.
As shown in FIG. 3, the lower end 27b of the D-shaped cross section of the shaft 27 is fitted and fixed on the upper side so that the lower end 27b of the shaft 27 rotates integrally with the first fitting concave portion 17a of the D-shaped cross section.
On the lower side, the upper end 58a of the D-shaped cross section of the small shaft 58 is fixed so as to rotate integrally by fitting into the second fitting recess 17b of the D-shaped cross section. This small shaft 58
The slide bearing 59 fixed to the lower end of the screw pump section 12 is rotatably supported by abutting against a hemispherical projection 59a of the slide bearing 59.

The slide bearing 59 is formed in a cup shape having a projection 59a on the bottom surface. As shown in FIG. 14, the inside of the side surface has a tapered shape extending from the bottom surface X 'toward the entrance Y'. May be formed as the slide bearing 59 '. When this slide bearing 59 'is adopted, even if the rotation center of the small shaft 58 is incorporated with a slight deviation from the center of the slide bearing 59', the small shaft 58 may damage or pry the inside of the slide bearing 59 '. The danger of falling is reduced.

In the second fitting concave portion 17b, the entrance portion is formed by a concave portion having a circular cross section, and a portion deeper than the middle portion is formed by a concave portion having a D cross section. As shown in FIG. 13, protrusions 17c, 17c are formed on the inner wall formed in a straight line in the inner part of the rear part, and formed in a shape protruding in an arc shape toward the inner peripheral side. The projections 17c, 17c are configured to abut on a plane portion of the upper end 58a of the small shaft 58. With such a configuration, the shaft 27 is rotatably supported in the straight pipe 13.

Next, the operation of the electric kettle pot device 2 incorporating the small pump device 1 configured as described above will be described.

First, as a preparatory operation for boiling water, the lid 5 is opened and water is poured into the water storage tank 4. Then, a part of the water injected into the water storage tank 4 is supplied from the communication port 21 to the suction unit 1.
1 and advance into the screw pump section 12.
At this time, depending on the volume of water charged into the water storage tank 4, the water further rises from the screw pump section 12 to an intermediate portion of the straight pipe 13. Then, it stops at a position corresponding to the volume of water charged into the water storage tank 4. The position of the water surface of the straight pipe 13 can be seen from the water level display window 9, which makes it possible to estimate the internal capacity of the water storage tank 4. That is, in this state, the water completely enters the suction unit 11 and the screw pump unit 12, and the water enters the water storage tank 4 and the straight pipe 13 to the middle part thereof.

In this state, the electric heating device 36 is energized to heat the water in the water storage tank 4. When the water boils, the steam generated at this time is discharged to the outside through a steam hole 5 a provided in the lid 5, and enters the motor 26, the movable contact 47, and the motor cap 44 containing the motor terminal 43 at the shoulder. Blocked by 6. In addition, the water that jumps off at the time of boiling is also blocked by the shoulder 6.

When discharging hot water, the closing lid 45 is closed and the discharge button (not shown) is operated with the movable contact 47 in contact with the motor terminal 43, whereby the motor 26 of the electric pump mechanism 16 is operated. Is driven in the forward rotation direction. Then, the motor output shaft 48 to which the induction magnet 49 is fixed rotates in the positive direction in the middle case 38.

When the induction magnet 49 rotates in the positive direction as described above, the impeller 19 whose blade 56 is magnetized is rotated.
Rotates together with the shaft 27 and the screw 17 in the forward direction. First, the hot water in the water storage tank 4 rises in the straight pipe 13 by the rotation of the screw 17. For this reason, the unheated water in the straight pipe 13 is pushed up and enters the centrifugal pump section side. On the other hand, after this, when water is supplied to the centrifugal pump section, the impeller 19
A negative pressure is generated at the center of rotation of, and a suction force for sucking water in the straight pipe 13 is generated in the vortex chamber. The water that has entered the vortex chamber 14 is supplied to the outside of the outer frame 3 from the discharge port 8 via the water supply pipe 28 and the discharge pipe 29 from the discharge section 53.

As described above, the first water sucked from the straight pipe 13 by the rotation of the impeller 19 and discharged from the discharge port 8 is not heated in the water storage tank 4 and thus remains cold. Following this cold water, the hot water heated in the water storage tank 4
When the impeller 19 is supplied from the straight pipe 13 to the impeller 19 by the rotation of the impeller 19, the hot water is supplied in the direction of the discharge port 8 by the rotation of the impeller 19.

At this time, the rotation center of the impeller 19 is at a negative pressure, and the hot water having a temperature close to the boiling point is vaporized or bubbles expand, so that the rotation center of the impeller 19 is air. May cause a full cavitation phenomenon. However, in the embodiment of the present invention, since the hot water is continuously supplied to the rotation center of the impeller 19 by the screw 17, the cavitation phenomenon is less likely to occur.

If the user dislikes the condition that the water to be discharged first is cold, that is, if hot water is required from the first glass, the following mode setting can be performed to cope with the situation. That is, by operating a predetermined button, first, the motor 26 of the electric pump mechanism 16 is driven in the reverse direction. Then, impeller 1
9. The shaft 27 and the screw 17 rotate in the reverse direction. In addition, when the impeller 19 rotates in the reverse direction, if the water is immersed up to the centrifugal pump part, a slight suction force works. However, by utilizing the fact that the suction force is reduced due to the structure of the vortex chamber 14 described above, the screw is used. 17 quickly returns the water in the straight pipe 13 to the water storage tank 4 side.

As a result, the water that is not heated outside the water storage tank 4 is mixed with the boiling water in the water storage tank 4 and is heated. Thereafter, the motor 26 is automatically driven in the forward direction, and hot water is discharged from the beginning. Instead of such a mode setting function, a return button (not shown) may be provided, and the operation may be performed in the reverse direction, and then the ejection button may be pressed.

When the electric kettle 2 is to be cleaned, the following operation is performed. First, the lid 5 is opened and an appropriate amount of water is poured into the water storage tank 4. Then, the water storage tank 4
A part of the water introduced into the inside is discharged from the communication port 21 to the suction part 11 and goes up the screw pump part 12 and the straight pipe 13.

In such a state, the cleaning agent is charged into the water storage tank 4 and, for example, a scale cleaning button (not shown) is operated. Then, the electric heating device 36 is energized to heat the water in the water storage tank 4. Simultaneously with the heating or after boiling,
The motor 26 is driven in reverse rotation. Thereby, the water in the straight pipe 13 is returned to the water storage tank 4. The motor 26 is rotated forward this time at a timing or a certain time after the water returns to the water storage tank 4. Then, the hot water charged with the cleaning agent in the water storage tank 4 is pumped into the straight pipe 13 and the vortex chamber 14. By repeating such an operation, the inside of the communication pipe 10 of the electric kettle 2, that is, the main parts such as the periphery of the impeller 19 and the periphery of the screw 17 are all cleaned.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. . For example, the small pump device 1 described above
Is configured as being incorporated in the electric kettle pot device 2, but may be employed in other liquid discharge devices, for example, a water heater, a water purifier, and the like. In addition, the small pump device of the present invention has an effect of preventing the cavitation phenomenon by supplying a liquid to the center of rotation of the impeller by a screw, and is used for a liquid discharge device of a type that pumps up a boiled liquid. It has become optimal.

Further, the small pump device 1 of the present embodiment
Is provided with a suction part 52 communicating the straight pipe 13 and the vortex chamber 14 at a position shifted from the rotation center of the impeller 19, but the suction part is formed at the rotation center of the impeller 19 in the vortex chamber 14. May be. However, in the present embodiment, by adopting the above-described configuration, it is possible to rotate the motor in the reverse direction and smoothly flow the liquid in the communication pipe 10 back to the water storage tank 4 side. This has the effect that the unheated liquid in the inside can be returned into the water storage tank 4 and the inside of the communication pipe 10 that can be warmed can be cleaned.

Further, the small pump device 1 of the present embodiment
Sets the outer diameter of the screw 17 to the screw pump section 1
Although it is configured to have a margin with respect to the inner diameter of 2, the gap between the outer peripheral edge of the screw 17 and the inner peripheral edge of the screw pump unit 12 may be configured to be small. In this case, the degree of difficulty in assembling and processing the parts may be increased, and the production efficiency may be reduced. However, as a finished product, a small pump device having a high pumping capacity of the screw portion is obtained.

[0075]

According to the miniature pump device of the present invention, since the pump mechanism is arranged at a position outside the water storage tank, it does not have a significant effect in the height direction when assembled into a product. It is a small-sized pump device which can have a degree of freedom in design and size of the pump. In addition, since the screw pump section is disposed below, the water in the communication pipe always rises or performs an operation of backflow to the water storage tank side, so that there is no phenomenon that the water runs idle and the water does not move. Thus, a small-sized pump device that operates reliably can be obtained.
Further, since the screw of the screw pump section does not need to have such a shape that the screw is so close to the inner wall of the communication pipe, it is not necessary to increase the precision in processing the parts, and a small-sized pump device with high productivity can be obtained.

Further, in the electric kettle pot device of the present invention, the pump mechanism is inserted into the minimum necessary space between the water storage tank and the outer frame, so that the overall height dimension is not significantly affected. In addition, the electric kettle can be provided with a degree of freedom in design and size. In addition, if a small pump capable of moving the liquid in the communication pipe in both directions is incorporated, it is possible to return the cold water in the communication pipe to the hot water in the water storage tank, thereby removing hot water from the first glass. An electric kettle can be supplied. In addition, the inside of the communication pipe and the pumping member can be washed simultaneously with the inside of the water storage tank.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view showing an entire electric kettle device incorporating a small pump device according to an embodiment of the present invention.

FIG. 2 is a partial sectional view showing an electric pump mechanism of the electric kettle pot apparatus shown in FIG.

FIG. 3 shows the reinforcing plate of the small pump device shown in FIG.
It is the figure seen from II direction.

FIG. 4 is a partial cross-sectional view showing the vicinity of a small pump device of the electric kettle pot device shown in FIG.

FIG. 5 is a view of the electric pump mechanism shown in FIG. 2 as viewed from a direction indicated by an arrow V.

FIG. 6 is a vertical sectional view showing a case body portion of the small pump device shown in FIG. 2 as viewed from a direction indicated by an arrow VI.

FIG. 7 is a partial cross-sectional view showing, in an enlarged manner, a motor peripheral portion of the small pump device incorporated in the electric kettle pot device shown in FIG.

FIG. 8 is a view of the case body shown in FIG. 6 as viewed from the direction of arrow VIII.

FIG. 9 is a sectional view taken along the line IX-IX of the case body shown in FIG. 8;

FIG. 10 is a longitudinal sectional view showing an impeller of the small pump device shown in FIG. 2;

11 is a longitudinal sectional view showing a modified example of the bearing of the small pump device shown in FIG.

FIG. 12 is a longitudinal sectional view showing a screw of the small pump device shown in FIG. 2;

FIG. 13 shows the shaft portion of the screw shown in FIG.
It is the figure seen from II direction.

14 is a longitudinal sectional view showing a modified example of the slide bearing of the small pump device shown in FIG.

FIG. 15 is a schematic view showing the whole of a conventional electric kettle.

16 is a diagram showing the electric kettle shown in FIG. 15 from above.

FIG. 17 is a longitudinal sectional view showing a conventional small pump device.

FIG. 18 is a longitudinal sectional view showing another conventional small pump device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small pump apparatus 2 Electric kettle pot apparatus 3 Outer frame 4 Water storage tank 10 Communication pipe 12 Screw pump part 13 Straight pipe (part of rising part) 14 Vortex chamber 15 Discharge part 16 Electric pump mechanism 17 Screw 18 Case body ( Part of the centrifugal pump section) 19 impeller 26 motor 27 shaft 36 electric heating device 48 motor output shaft 52 suction section 53 discharge section 54 slope

Claims (6)

[Claims] 1. A water storage tank for storing a liquid, a rising part communicating with a lower part of the water storage tank, and a discharge part communicating with the rising part, and a communication for discharging the liquid in the water storage tank to the outside. In a small pump device provided with a pipe and an electric pump mechanism arranged at an intermediate portion of the communication pipe for pumping the liquid, an impeller which becomes a part of the electric pump mechanism is provided above the rising portion. A small pump device comprising: a centrifugal pump section; and a screw pump section having a screw which is a part of the electric pump mechanism below the rising section. 2. A two-way rotating motor serving as a driving source of the electric pump mechanism is disposed above the outer frame body, and the impeller and the screw rotate integrally with an output shaft of the motor. 2. The small pump device according to claim 1, wherein the pump device is installed coaxially with a shaft. 3. Above the rising portion, a suction portion for sucking the liquid on the water storage tank side and a discharge portion for discharging the liquid sucked from the suction portion toward the discharge portion are provided. 3. The small pump device according to claim 1, wherein a vortex chamber in which the impeller is arranged is provided, and a suction portion of the vortex chamber is formed at a position shifted from a rotation center of the impeller. 4. In the vicinity of the suction section, when the impeller rotates forward, liquid is easily sucked into the swirl chamber from the suction section,
4. The small pump device according to claim 3, wherein a slope portion is provided for facilitating the liquid in the vortex chamber to flow backward from the suction portion when the impeller rotates in the reverse direction. 5. A water storage tank for storing a liquid inside the outer frame, an electric heating device for heating the liquid in the water storage tank, and a rising portion communicating with a lower portion of the water storage tank and a rising portion communicating with the rising portion. A communication pipe for discharging the liquid in the water storage tank to the outside of the outer frame body, the communication pipe having a discharge portion for communicating with the outside of the outer frame body, and the liquid disposed in a middle portion of the communication pipe; An electric kettle device provided with a small pump device provided with an electric pump mechanism for pumping water, wherein at least one water pumping member is disposed above and below the rising portion of the communication pipe. Kettle pot device. 6. The centrifugal pump having an impeller, wherein the rising portion is disposed between the water storage tank and the outer frame, and a portion of the plurality of pumping members disposed above the rising portion is constituted by an impeller. 6. The electric kettle pot device according to claim 5, wherein the device disposed below is constituted by a screw pump having a screw.