JPH04197255A - Cup water feeder - Google Patents

Abstract

PURPOSE:To allow easy resetting by regulation of the variable resistance of a comparator by supporting a cup receiving base with a pressure sensor and controlling the start and stop of water feed by the set value of the comparator of a control circuit in accordance with the electric signal from the pressure sensor. CONSTITUTION:An optical sensor 40 is installed to a water feed pipe 14 and the electric signal of this sensor is inputted to the control circuit 30. The optical sensor consists of a light projecting part 41 and a light receiving part 42. The light emitted by the light projecting part 41 is reflected on the surface and enters the light receiving part 42 if there is the cup 12 on the cup receiving base 10. The light does not enter the light receiving part unless there is no cup on the receiving base. The electric signal V of the pressure sensor 20 is inputted to the control circuit 30 as well. The control circuit 30 opens a water feed valve 15 only when the electric signal of the optical sensor 40 is on and the electric signal V of the pressure sensor 20 is smaller than the set value V2 corresponding to the electric signal of the pressure sensor when a prescribed volume of water enters the cup 12. The control circuit closes the water feed valve 15 on other occasions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a water supply device such as a dental unit.

[Prior Art] A device in which a crown holder in a dental unit is supported movably up and down by a spring and starts and stops water supply based on the vertical position of the socket holder is known from Japanese Patent Publication No. 56-11455 and the like. This known device does not malfunction when using a relatively heavy metal tip, but it tends to malfunction when using a light paper tip because the change in the tip holder position depending on the presence or absence of an empty tip is small. In order to solve this problem, the applicant uses an optical sensor to detect the presence or absence of the tip.
We have proposed a device that starts and stops water supply by detecting the presence or absence of a predetermined amount of water based on the upper and lower positions of a drop holder (Japanese Patent Laid-Open No. 2-4361).

[Problems to be Solved by the Invention] The conventional method uses a spring to support a pot cradle so that it can rise and fall freely, and stops water supply by detecting the vertical position of the cradle when a predetermined amount of water enters the pot. The reference position for stopping the water supply differs depending on the weight of the tap, so if you change the tap from heavy metal to light paper or vice versa, the reference position must be readjusted. There was a problem that the adjustment was complicated and could only be done by someone who was familiar with the device.

The present invention was made to solve this problem, and its purpose is to provide a device that allows easy adjustment of the reference position according to the weight of the tip used.

[Means for Solving the Problems] One of the means adopted by the present invention to achieve the above object is to support the pot holder with a pressure sensor, and a control circuit opens and closes the water supply valve based on the output of the pressure sensor. There is a particular thing.

As the pressure sensor, a piezoelectric element type that uses a piezo effect that directly converts pressure into an electrical quantity, a strain gauge type that converts pressure into a displacement, and converts it into an electrical quantity, etc. can be used. In the case of relatively heavy tips such as those made of metal, the presence or absence of the tip and the amount of water supplied are detected only by a pressure sensor, but in the case of lighter tips made of plastic or paper,
It is desirable to detect the presence or absence of the tip using another sensor, such as an optical sensor, rather than a pressure sensor.

[Function] The pressure sensor that supports the tip pedestal outputs an electric signal (■) according to the load to the control circuit. The control circuit uses that electrical signal■
is compared with a set value V1 corresponding to the load when the empty tip is on the tip saucer and a set value V2 corresponding to the load when the tip is filled with a predetermined amount of water, and when Vl < V < V2, water is supplied. Open the valve. As a result, water is supplied only when there is a pot on the pedestal and the pot does not contain a predetermined amount of water, and water supply is automatically stopped when the predetermined amount of water is filled.

Even if there is no tip on the pedestal, the pressure sensor outputs an electric signal vO corresponding to the weight of the pedestal to the control circuit. Heavy tips such as those made of metal have a large difference between 0 and Vl, so there is no problem, but plastic or paper tips have a small weight, so they tend to malfunction because the difference between 0 and Vl is small. In order to prevent this malfunction, the presence or absence of the tip is detected by another sensor, such as an optical sensor, and signals from the optical sensor and pressure sensor are input to the control circuit. The control circuit opens the water supply valve only when the electrical signal from the optical sensor is on (with a stop) and V<V2, and closes the water supply valve at all other times.

[Example] The apparatus of the present invention will be explained based on embodiments shown in the drawings.

As shown in FIG.
An electrical signal (1) based on the load received by the pressure sensor enters the control circuit 30. The control circuit 30 receives the electric signal V from the pressure sensor 2 when the tip 12 is not on the tip holder 10.
When it is larger than the set value Vl corresponding to an electric signal of 0 and smaller than the set value v2 corresponding to the electric signal of the pressure sensor 20 when a predetermined amount of water enters the tip 12 on the tip holder 10, The water supply valve 15 of the water supply pipe 14 is opened, but the water supply valve 15 is closed at other times. Setting value V1. V
2 changes depending on the load on the tip 12, but the control circuit 3
0 is attached with a dial 35 for adjusting these set values.

FIG. 2 is a circuit diagram showing the main part of the control circuit 30, in which the amplified electrical signal V of the pressure sensor 20 enters parallel comparators 31 and 32. As shown in FIG. 3, one comparator 31 is off (0) when V≦v1, on (1) when v>Vl, and the other comparator 32 is on (
1), outputs off (0) at V2V5. Both output signals enter the AND gate 33, so vt <V<V2
The water supply valve electromagnetic coil 35 is turned on and opens the water supply valve only when this occurs, and the water supply valve is closed at other times. vl and v2
can be changed by adjusting variable resistors VR1 and VR2 shown in FIG. 2 with dials. In this manner, the water supply valve automatically opens to supply water only when the top 12 is placed on the top holder 10 and there is not a predetermined amount of water therein. When the top 12 is not on the pedestal 10 and a predetermined amount of water enters the top 12, water supply is stopped.

In this embodiment, the presence or absence of a tip is detected by comparing the electrical signal V of the pressure sensor with a set value v1 corresponding to the sum of the empty tip weight and the weight of the tip pedestal. However, even if there is no tip on the tip holder, the pressure sensor outputs an electric signal 0 corresponding to the weight of the tip holder to the control circuit. In the case of a relatively heavy metal tip, the difference between vO and ■1 is large, so malfunctions will not occur, but in the case of a light paper tip, the difference between vO and ■1 is small, and malfunctions are likely to occur. In order to prevent malfunction, the embodiment shown in FIGS. 4 and 5 uses a separate sensor to detect the presence or absence of the tip.

As shown in FIG. 4, an optical sensor 40 is attached to the water supply pipe 14, and an electrical signal from the sensor is input to the control circuit 30.

The optical sensor consists of a light emitter 41 and a light receiver 42.
If there is a tip 12 on the tip holder 10, the light emitted by No. 1 will be reflected from the surface and enter the light receiving section 42, and if there is no tip on the holder, no light will enter the light receiving section.The presence or absence of the tip cannot be detected. It is not necessary to limit the sensor to an optical sensor, and other sensors such as a limit switch, a proximity switch, a near limiter, etc. may be used.

The electrical signal V of the pressure sensor 20 is also input to the control circuit 30 as in the previous embodiment. The control circuit 30 is configured such that the electrical signal of the optical sensor 40 is on (with a switch) and the pressure sensor 2 is on.
The water supply valve 15 is opened only when the electric signal 0 of close.

As shown in FIG. 5, the light emitting guide LE of the light projecting section 41
Infrared rays are always intermittently radiated from D by a multivibrator. This infrared ray is transmitted to the tip 12 on the pedestal 10.
The light is reflected by the surface of the light receiving section 42 and enters the phototransistor of the light receiving section 42 . The signal generated by the light incident on the phototransistor is amplified and enters one of the AND gates 33 via the rectifying and smoothing circuit and the Schmitt circuit. Pressure sensor 20
The electrical signal enters the comparator 32 via a differential amplifier, and the output of that comparator enters the other of the AND gates 33. The set value v2 of the comparator 32 is the variable resistance VR
The reason why the 0 light-emitting diode, which can be adjusted by the dial 35 (Fig. 4) directly connected to 2, is driven by a multivibrator is that the receiving circuit is configured with an AC amplifier and is not affected by external light. be. The AND gate 33 is set when the electric signal from the optical sensor 40 is on (with a stop), and when the electric signal from the pressure sensor 20 is V<V2
Only when this happens, the transistor is turned on to operate the water supply electromagnetic coil 35 to open the water supply valve, and at other times, the water supply valve is closed. Since this embodiment does not detect the presence or absence of a tip based on its weight, malfunctions will not occur even if a lightweight tip made of paper or plastic is used.

Similar to the embodiment described above, the water supply valve opens to supply water only when the pot 12 is placed on the pedestal 10 and the amount of water in it is less than a predetermined amount.

[Effects of the Invention] As described above, the device of the present invention supports the cup holder with a spring so that it can be raised and lowered, and the water supply start and stop is controlled by the vertical position of the holder. It is supported by a pressure sensor, and the start and stop of water supply is controlled by the set value of the comparator in the control circuit based on the electrical signal from the pressure sensor, so even if the weight of the cot used changes, the variable resistance of the comparator It has an excellent effect in that it can be easily reset by adjusting.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus according to an embodiment of the present invention, and FIG.
3 is a diagram showing the output of the control circuit, FIG. 4 is a schematic diagram of another embodiment, and FIG. 5 is a circuit diagram of the device shown in FIG. 4. In the figure, numeral 10 is a tip holder, 12 is a tip, 1
4 is a water supply pipe, 15 is a water supply valve, 20 is a pressure sensor, 30 is a control circuit, 35 is a dial, 40 is a light sensor, VRl
, VH2 indicate variable resistances, respectively.

Claims (1)

[Claims] 1) A cup holder (10), a cup (12) placed on the cup holder, and a water supply pipe (14) for pouring water into the cup.
In the cup water supply apparatus, the cup holder is supported by a pressure sensor (20), and a water supply valve (15) that opens and closes the water supply pipe, and a control circuit (30) that opens and closes the water supply valve. A cup water supply device characterized in that an electric signal (V) from a pressure sensor is input to the control circuit, and the control circuit opens the water supply valve only when the electric signal falls within a predetermined range. 2) A cup holder (10), a cup (12) to be placed on the cup holder, and a water supply pipe (14) for pouring water into the cup.
In the cup water supply apparatus, the cup holder is supported by a pressure sensor (20), and a water supply valve (15) that opens and closes the water supply pipe, and a control circuit (30) that opens and closes the water supply valve. A sensor (40) is attached to detect the presence or absence of the cup on the cup pedestal, and electrical signals from the pressure sensor (20) and the cup detection sensor (40) are both input to the control circuit (30). The control circuit opens the water supply valve only when the electrical signal from the cup detection sensor (40) indicates "cup present" and the electrical signal V from the pressure sensor (20) is smaller than a predetermined value. A cup water supply device featuring: