JPH0350822Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a liquid level display device for an electric hot water storage container, and is used, for example, in an electric pot.

(Prior Art) In electric pots, irrespective of whether they are boiling type or not, countermeasures against dry boiling are taken when the contents are heated by a heater. However, completely empty cooking can lead to accidents. In order to prevent this, a liquid amount display window is sometimes provided through which the liquid amount can be seen from the outside. Even this is not enough to attract the attention of users, and is often overlooked.
When the liquid level drops to the point where it is out of the liquid volume viewing range, there is no gas-liquid boundary in the liquid volume viewing range and the appearance is uniform, so it becomes difficult to know when it is close to dry cooking. It could happen.

Therefore, the idea is to use a transparent liquid level display tube to optically detect whether the remaining amount has reached the usable limit or the remaining amount is just short of the usable limit, and to provide a special display at the time of detection. It will be done.

(Problem that the invention aims to solve) However, the optical sensor requires a mounting structure, an electrical connection, and a structure that optically isolates the transparent liquid level display tube from the front side where the liquid level is displayed. be.

For this reason, simply using the required number of optical sensors will increase the number of parts and assembly man-hours, leading to a significant increase in cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid level display device for an electric hot water storage container that can solve the above-mentioned problems by using a plurality of optical sensors with a simple structure.

(Means for solving the problems) In order to achieve the above objectives, the present invention
In an electric hot water storage container equipped with a transparent liquid level display tube connected to the vessel body so as to maintain the same liquid level as that inside the vessel, there are multiple methods of detecting the presence or absence of liquid in the liquid level display tube at different height positions. sensors are installed on the same electric circuit board, and the plurality of sensors are arranged around the liquid level display tube, with the plurality of sensors facing inside a box provided over the plurality of detection positions. It is characterized by being optically isolated from the front side where the surface weight is displayed.

(Function) A plurality of sensors are installed on the same electric circuit board, and this circuit board serves as a common support member so that they can be handled as one component during assembly work, and can be handled as a single component in conjunction with the electric circuit on the board. At the same time as the connection, support on the circuit board as a support member is achieved, making it possible to eliminate the need for a special support member or work.

In addition, a box is provided over the installation position of the plurality of sensors, which is optically isolated from the front side where the plurality of sensors are inserted and the liquid quantity display tube is displayed.
A plurality of required sensors can be inserted into one box to achieve optical isolation from the respective front sides.

(Embodiment) The first embodiment of the present invention shown in FIGS. 1 to 8 shows the case of an air pump type tabletop electric pot, and as shown in FIG. An inner container 2 wrapped with 1 is housed and held in an outer case 3 to form a container body 4. The mouth portion 2a of the inner container 2 is connected to the upper end of the outer case 3 by a shoulder member 5 made of synthetic resin, and the outer lid 7 can be opened/closed and attached/detached by a shaft 6 on a rear hook-shaped bearing 9 of the shoulder member 5. It is pivoted to. An inner cover 8 that is attached to the mouth 2a of the inner container 2 is attached to the lower surface of the outer cover 7, and is opened and closed integrally with the outer cover 7.

A bellows pump 11 is provided inside the outer lid 7 and is operated by a pressing plate 10 on the upper surface of the outer lid 7. Pressurized air is sent into the container 2 to pressurize the liquid inside. The air supply passage 13 is connected to the outer cover 7 through the branch hole 14.
A steam vent passage 15 is provided to escape to the upper surface of the inner container 2, and the steam generated during heat retention and boiling by the heater 1 is released to the outside to prevent abnormal pressure rise in the inner container 2.

The branch hole 14 is switched to the air supply port 16 of the bellows pump bottom plate 12 and closed by a valve 36 that is moved down in conjunction with the pressing operation of the bellows pump 11, so that pressurized air is not supplied when the content liquid is pressurized. Steam vent passage 15
This prevents steam from escaping to the bellows pump 11 or from entering the bellows pump 11 when hot water is stored.

A lead-out passage 17 for guiding the pressurized content liquid upward to the outside of the inner container 2 is provided with its base end connected to the bottom of the content liquid 2, and a synthetic resin elbow 2 is provided at the upper end.
0 is connected. This elbow 20 is connected to an inverted U-shaped tube 23 fixed to the back side of a beak-shaped portion 5a of the shoulder member 5 that extends to one side. Inverted U-shaped tube 23
is the water stop valve 2 in the event of a fall just above the connection with the elbow 20.
5 is built-in, and the downward discharge port 19 at the tip has a slit 26 formed on the front side thereof that reaches from the lower end to a position above the full water position of the inner container 2.
A pipe cover 27 that surrounds the beak-like portion 5a is provided below the beak-like portion 5a of the vessel body 4.
a and the outer case 3 of the vessel body 4. At the bottom of the pipe cover 27 is an inverted U-shaped pipe 23.
A liquid injection guide tube 24 is detachably attached from below to receive the liquid discharged from the discharge port 19 in an open state to the atmosphere and flow it downward.

The slit 26 is also involved in this open reception to the atmosphere, which reliably prevents siphon splash and the ejection of the contents in the event of rapid dispensing. The liquid injection guide tube 24 is removably fitted into the beak portion 5a of the shoulder member 5, and is connected to the discharge port 19.
The discharged liquid is received with a somewhat large diameter without difficulty, is rectified by a rectifying plate 28, and is made to flow quietly downward.

Although a check valve 29 is provided in the air supply passage 13, the check valve 29 may become temporarily unstable during a fall and may cause the contents to flow out. Although the amount of steam flowing out is small, if it flows out from the outer lid 7 through the steam vent passage 15, it may be dangerous if there is an infant in the area. Therefore, in addition to the air supply port 16 of the bellows pump bottom plate 12, the air supply path 1 is
An auxiliary communication hole 30 is provided which communicates with the air supply passage 15, and the weight valve 13 is normally kept closed. When the content liquid flows out into the air supply passage 15, the outflow liquid tries to fill the air supply passage 15 and the weight valve 13 is closed. 31 and flows into the bellows pump 11 through the auxiliary communication hole 30,
Outflow to the steam vent passage 15 side through the branch hole 14 is suppressed.

Note that the steam sensor 3 is attached to a part of the shoulder member 5 from the back side.
7 protrudes and faces into the steam vent passage 15 from a part of the hole 15a, so that boiling of the content liquid is detected based on the steam temperature.

The rising portion of the content liquid outlet path 17 is a liquid volume display portion made of a transparent tube 17b, which can be seen through a transparent window 42 provided in a cover 41 fitted to the front portion of the exterior body 1. Further, a resin splint 43 with wings 43a is provided at the rear half of the transparent tube 17b of the liquid content pouring conduit 17 to catch external light and prevent leakage to the rear. resin panel 4
1 is provided with an operation button 44a for a re-boiling switch 44 that allows the heater 1 to boil the content liquid at a suitable time.
6. A water supply display section 47 and a previous level remaining amount display section 48 are provided using light emitting diodes. The portions where these are provided are covered flush with a transparent resin cover sheet 49, and necessary indications are printed on the back side of the cover sheet 49. The cover sheet 49 is the transparent window 42 of the cover 42
It can also be extended to the opening of the window and covered flush with it, and can be used in place of the transparent window plate 50. In that case, a liquid volume scale can be printed on the back side of the cover sheet 49.

The lower back side of the cover 41 is a liquid level detection box 51.
are integrally formed. Box 51 is shown in Fig.
As shown in FIG.
Post-stage residual amount detection means 53 consisting of a light emitting diode 53a and a light receiving element 53b are housed vertically, and changes in the remaining amount in the inner container 2 are detected through the transparent tube 17b.

Each light emitting diode 52a, 53a and each light receiving element 52b, 53b are mounted on a printed circuit board 54.
The board 45 is placed upright on one side of the box 51, and is placed at a predetermined position within the box 51 by fitting the board 45 into the stepped portion 51a of the opening of the box 51 and screwing it in with the screws 55.

Light emitting diode 5 housed in box 51
2a, 53a and the light receiving elements 52b, 53b are the third
As shown in the figure, the transparent tube 17b
When there is no liquid inside, the light emitting diodes 52a and 53a
The light 56 from the
However, if there is liquid, the light 56 travels as shown in FIG. 4 and is detected by the light receiving elements 52b, 53b.
It doesn't reach 3b. Note that 51b is a window provided in the box 51 through which light 56 passes.

In this way, whether or not the light reaches the light receiving elements 52b and 53b can be used to detect whether there is liquid at the opposing height, and when the liquid runs out, the remaining amount will be below the opposing height. It means that it has passed. Here, each light emitting diode 52a, 53a and each light receiving element 52
b, 53b detect the presence or absence of liquid by facing each other horizontally using the difference in refraction depending on the presence or absence of liquid with respect to the transparent tube 17b.
The remaining amount state can be accurately detected without the unsightly and unsanitary procedure of putting a light-shielding float inside the tank.

A ring 41a that fits into the transparent tube 17b is integrally formed at the upper and lower ends of the resin panel 41. After fitting the transparent tube 17b with the rings 41a, 41a, the resin panel 41 and the transparent tube 1 are connected immediately adjacent to each other.
7b are attracted together by a rubber band 95, and together with the high frictional properties of the rubber band 95, the transparent tube 17b is prevented from coming off from the resin panel 41, so that both can be handled as a unit at the assembly stage.

A thermistor 63 is attached to a recessed portion 61 provided at the back of the inner container 2 using a mounting plate 33, and a temperature fuse 60 is attached to the bottom of the inner container 2.

When the front stage remaining amount display means 52 detects a predetermined front stage remaining amount state, the remaining amount display section 48 is turned on, and when the rear stage remaining amount display means 53 detects a predetermined rear stage remaining amount state, a buzzer 65 is activated.

A series of controls such as energization control of the heater 1, determination of the remaining amount detection, and corresponding display are performed by a microcomputer (hereinafter referred to as microcomputer) 66. The microcomputer 66 is the CPU
It is sufficient to have a ROM, and the circuit board 67 is equipped with other necessary circuit parts.

The board 67 is integrally formed with a part of the annular bottom plate 68 attached to the lower end of the outer case 3, and
9b is housed from below in a downward-opening microcontroller box 69 and secured with screws 70, and a heat shield plate 72 covered from above is also secured with screws 73. The top plate 69a of the microbox 69 has four spacer protrusions 71 on its lower surface for screwing the board 67, and four spacer protrusions 73 for attaching the heat shield plate 72 on the top surface, which are the same as the spacer protrusions 71. located at the location.

The screws 70 of the board 67 are fastened using the three spacer protrusions 71 and 73 so as not to penetrate from the bottom to the top.
2 has a skirt wall 72a that fits around the outer periphery of the microbox 69, and is mounted by making a hole 72b formed in the skirt wall 72a elastically engage with an engaging claw 69c formed on the outer periphery of the microbox 69,
In order to stabilize the installation, the spacer protrusions 71 and 73 at one other location are used to prevent the screws from penetrating from above to below, and are screwed together with screws 74. As a result, the microbox 69 has no upper and lower penetration parts, and even if overflow flows down from above, it will not enter the microbox 69, and the electronic circuits installed on the board 67 inside the microbox 69 will be protected. can be protected from said overflow.

A heat insulating material 78 is wrapped around the outside of the upper half of the inner container 2, and a heat shield plate 75 is provided around the outside of the lower half. The heater 1 is housed in a band-like case 76 and wrapped around the inner container 2, but since the heater 1 itself is usually only provided in the range X shown in FIG. A heat plate 75 is provided, and a bottom heat shield plate 77 is also provided at the folded portion of the heat shield plate 75 toward the lower side of the inner container 2.

As a result, the board 67 absorbs heat from the heater 1 through the folded portion of the heat shield plate 75, the bottom heat shield plate 77, the heat shield plate 72, the microbox 69, and the air layer between them. shielded and provided with adequate thermal protection.

The heat shield plate 75 and the bottom heat shield plate 77 are simultaneously attached with screws 81 along with a mounting plate 80 of the temperature fuse 60 to a mounting bracket 79 attached to the bottom of the inner container 2 by welding or the like. Note that by attaching with the screws 81, another heat shield plate 72 can also be attached as shown in the imaginary line. In that case, spacer ring 82
It is recommended to use

As shown in FIG. 6, the microbox 69 is
It is provided at a position away from the range X in which the heater 1 is provided, so that it is also protected from the thermal influence from the heater 1. The same method may be used even when the heater 1' is provided on the bottom of the inner container 2 at an angle.

Control circuit 91 including a circuit on microcomputer board 67
is as shown in the block diagram shown in FIG. 7, and is connected to various external electronic components and operating components necessary for the microcomputer 66.

Now, a series of control operations will be explained according to the control flowchart shown in FIG. 8. When the power is turned on, necessary initial settings are performed in step #1, and then
Move to step #2, activate the buzzer 65,
The start of heating is indicated externally with a “pitsu” sound,
Notifies the user of the start of use of the electric pot and urges caution in handling it thereafter. Next, in step #3, it is determined whether the content liquid is empty or not based on whether or not the latter-stage remaining amount detection means 53 detects the content liquid. It should be noted that even when the latter remaining amount detection means 53 no longer detects the liquid content, it takes some time until an appropriate amount remains and a complete empty cooking state is reached. If it is not empty, move from step #4 to step #12 to determine if the electric pot is safe to use and take necessary preparations; if not, return to step #1 and start from the beginning. The flow is repeated.

If it can be used, the process moves to step #13, and the first remaining amount detection means 5 determines whether the content liquid is above the water supply line.
The determination is made based on whether or not 2 detects the liquid content.
If the pre-stage remaining amount detection means 52 does not detect the content liquid, it is below the water supply line, and the process moves to step #14, where the water supply display section 47 is turned on to externally display that the water supply has reached the required remaining amount. After prompting water supply, the process moves to step #16.

If the water supply line has not been reached, proceed to step #15.
Then, the water supply display section 47 is turned off and the process moves to step #16.

In step #16, the empty buzzer flag is set to "0", and then the process moves to step #17.
It is determined whether the reboiling switch 44 is on. If reboil switch 44 is on, step #18
Activate the buzzer 65 and make a beep sound to display the response externally, set the boiling flag to "1" in step #19, and proceed to step #20.
to move to. If the reboiling switch 44 is off, steps #18 and #19 are not executed and the process immediately proceeds to step #20.

In step #20, it is determined whether the thermistor 63 is detecting a predetermined temperature. If it is not detected, proceed to step #21 and determine whether the boiling flag is "1". If it is "1", continue as is.
If it is not "1", the process moves to step #22, and if the thermistor 63 is below the boiling temperature, the process moves to step #23, and both the main heater 1a and sub-heater 1b of the heater 1 are turned on. Thereafter, in step #24, the boiling display section 45 is turned on to externally display that the boiling condition is in use, and the heat retention display section 46 is turned off.

Next, the process moves to step #25 and the steam sensor 37
Determine whether the temperature is below the boiling temperature. If the temperature is below, the process moves to step #3 and heating for boiling is repeated. If it is below the boiling temperature in step #25, the process moves to step #26, where the main heater 1a and sub-heater 1b are turned off, the boiling flag is set to "0" in step #27, and the boiling indicator 4 is turned off in step #28.
7 is flashed and the buzzer 65 is activated to make "pitsu" and "pitsu" sound five times, and an external display is displayed to indicate that the boiling state has been reached. After this, the process moves to step #3.

If the thermistor 63 is at the predetermined temperature in step #20, the process moves to step #31, where the main heater 1a and sub-heater b are turned off, and then the process moves to step #32, and only when the boiling flag is "1", the process proceeds to step #31. Move to #33 and keep warm display section 46
After turning off, the process moves to step #25 to perform boiling processing.

If the boiling flag is not "1" in step #32, it means that the temperature is kept warm, so the process goes to step #34, where the boiling indicator 45 is turned off and the heat retention display 46 is turned on to externally display that the temperature is being kept warm. . Then, in step #35, the thermistor 63
It is determined whether or not the temperature is above a predetermined temperature, and if it is below, the sub-heater 1b is turned on in step #36, and then
If the temperature is above, the process directly proceeds to step #37, and if the thermistor 63 is below the predetermined temperature, the process continues as is, and if it is above, the process proceeds to step #38, where the sub-heater 1b is turned off, and then the process proceeds to step #3, where the heat retention state is repeated. .

When it is determined in step #3 that the content liquid is empty, the process moves to step #41, and only when it is determined that the content is empty a predetermined number of times in succession, the process moves to step #24, where the boiling indicator 45 and the heat retention are displayed. After turning off the display section 46 and water supply display section 47,
At step #43, the main heater 1a and sub-heater 1b are turned off, and at step #44, the water supply display section #47 is blinked to externally display the empty state when visually displayed.

Next, in step #45, it is determined whether the empty buzzer flag is "1" or not, and if it is not "1", the buzzer 65 is activated in step #46 to continuously sound "pitsu" and "pitsu", and step #47
After setting the empty buzzer flag to "1", the process returns to step #3. If the empty buzzer flag is "1" in step #45, the process directly returns to step #3.

In the embodiment shown in FIGS. 9 and 10, a liquid level detection box 5 is provided almost below the window 42 of the resin panel 21.
1, and a recess 51c is formed for receiving the lower end of the transparent tube 17b of the outlet path 17 and the portion below it bent toward the inner container 2, as shown in FIG. This has the advantage that the lower part of the lead-out portion 17 can be directly positioned by the recess 51c.

(Effects of the invention) According to the invention of the present application, a plurality of sensors are installed on the same electric circuit board, and this circuit board serves as a common support member, so that they can be handled as one component during assembly work. In addition, support on the circuit board as a support member is achieved at the same time as connection with the electric circuit on the board, eliminating the need for special support members or work.In addition, multiple sensors can be inserted to display the liquid level in the liquid level display tube. A box is provided that is optically isolated from the front side where a plurality of sensors are installed, and a plurality of necessary sensors are inserted into this one box, and each box is optically isolated from the front side. Since isolation is achieved, optical detection of liquid at multiple locations can be achieved with a simple structure that requires fewer parts to handle and fewer assembly steps, and costs can be significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a perspective view of the liquid level display section, Figs. Fig. 2 is a perspective view of a portion of the control circuit as seen from the front side, Fig. 6 is a plan view of the bottom plate, Fig. 7 is a block diagram of the control circuit, Fig. 8 is a control flowchart, and Figs. 9 and 10 are FIG. 7 is a perspective view and a cross-sectional view of a portion of a modified example of the liquid amount display section. 17b... Transparent tube, 52... Front remaining amount detection means, 53... Remaining amount detection means, 47... Front remaining amount display section, 47, 65... Remaining amount display section, 51
...BOX, 54... Board.

Claims (1)

[Scope of Claim for Utility Model Registration] In an electric hot water storage container equipped with a transparent liquid level display tube connected to the vessel body so as to maintain the same liquid level as inside the vessel, the presence or absence of liquid in the liquid level display tube may be varied. A plurality of sensors for detecting at height positions are installed on the same electric circuit board, and the plurality of sensors are faced in a box provided over the plurality of detection positions. A liquid level display device for an electric hot water storage container, characterized in that a sensor is optically isolated from the front side of the liquid level display tube around which the liquid level is displayed.