JP4249891B2 - Pressure sensor, water level detection device and hot water supply system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure sensor , a water level detection device, and a hot water supply system that are used for detection of a water level change such as a bathtub water level and water level monitoring.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a fully automatic bath water heater that automatically performs hot water supply and bath water tracking, a pressure sensor installed in a casing of the bath water heater is used to detect the bath water level. The detection accuracy of the pressure sensor that has been used for water level detection has a minimum resolution of about 10 mm for the purpose of keeping the bath water level at a constant level. In addition, the body fat percentage measurement using bath water requires a minimum resolution capable of detecting a water level difference of 0.5 mm or less because it is necessary to accurately measure the body volume.
[0003]
[Problems to be solved by the invention]
By the way, the casing of the bath water heater in which the pressure sensor is installed is provided with a device that causes an internal pressure fluctuation in the casing, such as a combustion air supply fan that rotates at high speed by a motor. For example, when the air supply fan rotates, a negative pressure of several millimeters is generated in the casing, and the negative pressure forms the back pressure of the pressure sensor. As a result, the pressure sensor is detected as if the water level has risen. Output, and this detection error causes adverse effects on water level control and body fat percentage measurement.
[0004]
In order to avoid such inconveniences, the installation of the pressure sensor outside the casing, etc., or the negative pressure generated when the air supply fan rotates is measured in advance, and the rotation of the fan motor Sometimes, there is a method of correcting the output value of the pressure sensor with a negative pressure component. However, the former has restrictions on the installation position of the pressure sensor and the arrangement relationship with other devices, and the latter has no restrictions like the former, but the air supply filter at the inlet of the casing is blocked. Even in this case, since the output value of the pressure sensor fluctuates, the relationship between the rotational speed of the fan motor and the negative pressure shifts, and accurate pressure detection, that is, water level detection cannot be performed.
[0005]
Therefore, the present invention provides a pressure sensor that can accurately detect pressure without being restricted by the installation position in the casing, and provides a water level detection device that does not cause a measurement error due to fluctuations in internal pressure in the casing. This is the issue.
[0006]
[Means for Solving the Problems]
The pressure sensor or water level detection device of the present invention uses the back pressure of the sensor unit (114) as a casing in order to suppress changes in back pressure that occur in the pressure sensor due to fluctuations in the internal pressure of the casing (4) in which the pressure sensor (74) is installed. It opens to the outside, avoids the effects of fluctuations in the internal pressure of the casing, and suppresses measurement errors in pressure detection or water level detection.
[0007]
The pressure sensor according to the present invention is a pressure sensor installed in a casing with internal pressure fluctuation, and is connected to a conduit through which water flows and guides the water pressure from the conduit side, and the pressure guide tube portion A sensor frame fixed on the pressure guiding tube portion, provided on one side with a cylindrical portion to be inserted in, provided with a protruding portion on the other surface side, provided with a back pressure port inserted into the protruding portion on the cylindrical portion side , A support base that is surrounded by the cylinder portion of the sensor frame and is installed in the sensor frame, and has a through hole having a smaller diameter than the back pressure port, and the through hole is inserted through the back pressure port and the tube side. And a sensor element that is supported by the support, is installed with the pressure receiving surface facing the inside of the pressure guiding tube portion, and back pressure is released to the atmosphere by the through hole and the back pressure port, and the sensor frame Shirube圧gel is placed into a cylindrical portion covering the pressure-receiving surface of the sensor element If, formed between the water introduced into the guiding tube portion and the Shirube圧gel material, and the air layer exerting the pressure of the water to the pressure receiving surface of the sensor element,
It is characterized by providing. In other words, the back pressure of the sensor element is released to the atmosphere outside the casing from the back pressure port having a diameter larger than that of the through hole of the support base and the protruding portion of the sensor frame, thereby avoiding the influence of pressure fluctuations inside the casing. And detection accuracy can be increased.
[0008]
In the pressure sensor of the present invention is characterized in that the back pressure of the sensor element e Bei a conduit for opening to the outside of the casing. That is, by releasing the back pressure of the sensor element outside the casing through the pipe line, it is possible to avoid the influence of the pressure fluctuation in the casing and to improve the detection accuracy.
[0009]
The water level detection device of the present invention is a water level detection device for detecting the water level in the container through a pipe line connected to a container for storing water, and is provided with a cylindrical part inserted into the pressure guiding pipe part on one side, Provided with a protruding portion on the other surface side, provided with a back pressure port inserted into the protruding portion on the protruding portion, a sensor frame fixed to the pressure guiding tube portion, and surrounded by the cylindrical portion of the sensor frame A through hole having a smaller diameter than the back pressure port, which is installed in the sensor frame, is inserted into the back pressure port and the tube portion side, and the pressure guide tube is supported by the support table. A sensor element that is installed with the pressure receiving surface facing inside, and the back pressure is released to the atmosphere by the through hole and the back pressure port, and the pressure receiving pressure of the sensor element that is installed in the cylinder part of the sensor frame A pressure guiding gel material covering the surface, and the water introduced into the pressure guiding tube portion Wherein formed between the Shirube圧gel material, characterized in that it comprises an air layer exerting the pressure of the water to the pressure receiving surface of the sensor element. By opening the back pressure of the sensor element through the pipe line to the atmosphere outside the casing through the back pressure port with a diameter larger than the through hole of the support base and the protruding part of the sensor frame, the influence of pressure fluctuations inside the casing can be reduced. This can be avoided, and the detection accuracy of the water level due to pressure can be increased.
[0010]
In the water level detection device of the present invention, the container is a bathtub (2). That is, the pressure sensor is installed in the casing of the hot water supply device, and the detection accuracy of the bath water can be increased without being affected by the fluctuation of the internal pressure in the casing, so that highly accurate water level control or the like can be realized.
[0011]
The water level detection device of the present invention is characterized in that a pipe line for releasing the back pressure of the sensor element to the outside of the casing is provided. That is, even if the back pressure of the sensor element is released to the outside air through the exhaust means, the back pressure change can be suppressed.
Further, the hot water supply system of the present invention is a hot water supply system for detecting a water level through a pipe line connected to a bathtub, wherein a cylindrical portion to be inserted into the pressure guiding tube portion is provided on one surface side, and a protruding portion is provided on the other surface side. Providing a back pressure port that is inserted into the projecting portion on the cylindrical portion side, a sensor frame fixed to the pressure guiding tube portion, and surrounded by the cylindrical portion of the sensor frame and installed on the sensor frame, A through-hole having a smaller diameter than the back pressure port is formed, a support base through which the through-hole is inserted into the back pressure port and the cylindrical portion side, and a support surface supported by the support base, and a pressure receiving surface inside the pressure guiding tube portion. A sensor element that is installed to face and back pressure is released to the atmosphere by the through hole and the back pressure port, and a pressure guiding gel material that is installed in the cylinder portion of the sensor frame and covers the pressure receiving surface of the sensor element And the water introduced into the pressure guiding tube and the pressure guiding gel material Formed between, and an air layer exerting the pressure of the water to the pressure receiving surface of the sensor element, and detects the water level of the tub by the sensor element.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention and its embodiments will be described in detail with reference to examples shown in the drawings.
[0013]
FIG. 1 shows a bath water heater which is an embodiment of a pressure sensor , a water level detection device and a hot water supply system of the present invention. The bath water heater constitutes a hot water supply system that heats the clean water W to supply hot water HW to the bathtub 2 and the like, and reheats (reserves) the bathtub water BW. Inside the casing 4 of the bath water heater, a partitioned combustion chamber 6 for burning the fuel gas G is provided. Burners 8 and 10, a hot water supply heat exchanger 12, and a bath heat exchanger 14 are installed in the combustion chamber 6, and a combustion air supply fan 16 is provided in the lower part thereof, and a flue 17 is provided in the upper part thereof. There are provided exhaust ports 18 and 20 serving as exhaust means. That is, the combustion air supply fan 16 and the burners 8 and 10 installed inside the casing 4 suck the outside air into the combustion chamber 6 by rotation or combustion, and thus become an internal pressure fluctuation factor in the casing 4. In this embodiment, since it is a bath water heater, the tub 2 is illustrated as a container. However, as a target for detecting the water level by pressure, a container may be provided as a means for collecting water other than the tub 2, It is not limited to a bathtub.
[0014]
The fuel pipe 22 for supplying the fuel gas G to the burners 8 and 10 is provided with a main valve 24, a proportional valve 26 and an on / off valve 28 on the burner 8 side, and a proportional valve 30 and on / off valve on the burner 10 side. 32 and the like are provided, and supply or cutoff of the fuel gas G, adjustment of the supply amount, and the like are performed. As means for igniting the burners 8, 10, spark plugs 34, 36, an igniter 38, and the like are provided.
[0015]
A hot water supply pipe 40 is connected to the inlet side of the hot water supply heat exchanger 12, and a hot water supply pipe 42 is connected to the outlet side thereof. After the hot water W is heated by the heat exchanger 12, hot water HW is supplied through the hot water supply pipe 42. Is done. The water supply pipe 40 is provided with a water amount sensor 44, an incoming water temperature sensor 46, etc., and a hot water supply temperature sensor 48, a water control valve 50, etc. are provided on the hot water supply pipe 42 side, and between the water supply pipe 40 and the hot water supply pipe 42. A bypass pipe 52 and an electromagnetic valve 54 are provided. Hot water HW is supplied from a hot water supply pipe 56 for bath branched from the hot water supply pipe 42 to the return pipe 60 of the circulation path 58 on the bathtub 2 side. The hot water supply pipe 56 for bath is provided with a hot water solenoid valve 62, a check valve 64, a hot water amount sensor 66, and the like.
[0016]
A circulation path 58 is constituted by a forward pipe 70 and a return pipe 60 between the circulation device 68 attached to the bathtub 2 and the heat exchanger 14 for bath, and a pump 72 as a pressure feeding means is provided on the return pipe 60 side. As means for detecting the water level of the bath water BW, a pressure sensor 74, a temperature sensor 76 for detecting the temperature of the circulating bath water BW, a water flow switch 78 for detecting the presence or absence of circulating water, and the like are provided. A bypass pipe 82 including a bypass valve 80 is provided between the outgoing pipe 70 and the return pipe 60. The pressure sensor 74 is connected to a conduit 84 that allows the back pressure of the sensor unit 114 (FIG. 2) to communicate with the atmosphere outside the casing 4, and the open end thereof is guided outside the casing 4.
[0017]
In addition, an electrical board 86 is installed in the casing 4 as a control means for receiving detection outputs from various sensors and performing necessary control. The electrical board 86 is supplied with AC power.
[0018]
The pressure sensor 74 communicates with the bathtub water BW in the bathtub 2 through the return pipe 60, and is a means for detecting the pressure corresponding to the water level of the bathtub water BW. For example, as shown in FIG. It is attached with an attachment 88 as a sensor attachment member inserted in the middle part of the tube 60. The attachment 88 includes connecting pipe parts 90 and 92 connected to the return pipe 60 and a pressure guiding pipe part 94, and the connecting pipe parts 90 and 92 and the return pipe 60 interpose O-rings 96 and 98 which are watertight members. At the same time, they are tightly coupled by locking fasteners 100 and 102 which are fixing means.
[0019]
The sensor frame 106 of the pressure sensor 74 is fixed to the flange portion 104 of the pressure guiding tube portion 94 with a plurality of screws 108 as fixing means, and the cylindrical portion 110 of the sensor frame 106 is inserted into the pressure guiding tube portion 94. The pressure guiding tube portion 94 and the sensor frame 106 are tightly coupled by an O-ring 112 that is a watertight member fitted to the cylindrical portion 110 side.
[0020]
A sensor part 114 is installed in the cylindrical part 110 of the sensor frame 106. That is, an annular support base 116 made of glass or the like is installed in the central recess of the cylindrical part 110 and a sensor element 118 made of a silicon chip is disposed, and as a pressure guiding material covering the sensor element 118 and the support base 116. Silicon gel 120 is installed. An air layer 122 is formed on the lower surface side of the silicon gel 120, and the pressure P generated according to the water level of the bath water BW acts on the pressure receiving surface of the sensor element 118 via the air layer 122.
[0021]
The sensor element 118 is connected to gold wires 124 and 126 as output lead-out members, and the output is taken out through the gold wires 124 and 126. The ends of the gold wires 124 and 126 are electrically connected to leads 128 and 130 which are output terminals attached through the sensor frame 106.
[0022]
Further, a back pressure port 136 that communicates with the through hole 134 of the support base 116 and has a diameter larger than that of the through hole 134 is formed in the protrusion 132 formed at the center of the outer surface of the sensor frame 106. A pipe 84 that guides the back pressure of the sensor element 118 to the outside of the casing 4 (FIG. 1) is connected to the protrusion 132. This conduit 84 can be constituted by a flexible hose, for example. The upper surface of the sensor frame 106 is provided with a cover 142 that covers the connection portion between the leads 128 and 130 and the protruding portion 132 and the conduit 84, and the conduit 84 is a through hole formed on the ceiling surface of the cover 142. It is drawn from 144.
[0023]
Next, a control device that controls the water level in the bathtub 2 using output information of various sensors such as the pressure sensor 74 will be described.
[0024]
For example, as shown in FIG. 3, the water level control of the bathtub 2 is provided with a pressure sensor 74, a tapping temperature sensor 48, an incoming water temperature sensor 46, other sensors 44 and 66, and the detection outputs of the control unit 200. The signals are detected by the detection circuits 202, 204, 206, and 208, converted into digital signals by the A / D converters 210, 212, 214, and 216, and then added to the CPU 218 that is a calculation means. The CPU 218 is connected to a ROM 220 and a RAM 222 as storage means, and the control output output from the CPU 218 is applied to the drive circuits 224, 226, 228, 230, 232, 234, 236, 238, etc. Drive outputs are applied to the valves 28 and 32, the proportional valve 26, the spark plugs 34 and 36, the water control valve 50, the pump 72, and the like. Although not shown, other control means such as the proportional valve 30 are also controlled by a similar drive circuit. The control unit 200 is provided with a transmission / reception circuit 240 as means for exchanging data with the outside, and the CPU 218 and a remote controller 242 as remote operation means are connected via a transmission / reception circuit 240 by wire or wirelessly. Various signal transmission media such as radio waves and light can be used in radio.
[0025]
According to such a configuration, the bathtub water BW communicates with the pressure sensor 74 through the return pipe 60, and the pressure P corresponding to the water level of the bathtub water BW acts on the sensor element 118 of the pressure sensor 74. A voltage proportional to the output of the pressure sensor 74, that is, the water level of the bath water BW is generated at the leads 128 and 130.
[0026]
By the way, when the hot water is supplied, the burner 8 is combusted, so that the inside of the casing 4 is in a state lower than the atmospheric pressure, that is, a negative pressure state due to the combustion and the supply of the air supply fan 16. If the inside of the casing 4 changes under such a negative pressure state, when the back pressure of the pressure sensor 74 is opened in the casing 4, the effect appears prominently in the detection output. Since the pressure is open to the atmosphere outside the casing 4, it is not affected by fluctuations in the internal pressure inside the casing 4. For this reason, the pressure sensor 74 can detect only the water pressure acting through the return pipe 60, and can detect the pressure representing the water level with high accuracy.
[0027]
The water level detection based on such pressure detection can be performed with high accuracy since the back pressure of the pressure sensor 74 does not fluctuate similarly during the follow-up operation in which the burner 10 is combusted.
[0028]
Therefore, if the output of such a pressure sensor 74 is used, the water level of the bathtub 2 can be accurately controlled at the time of hot water supply, and the water level of the bathtub 2 can be accurately controlled even at the time of full automatic heat retention.
[0029]
Next, FIG. 4 shows a specific embodiment of a water level detection apparatus using the pressure sensor of the present invention. In this embodiment, a pressure sensor 74 constituting a water level detection device is installed on the return pipe 60 side built in the casing 4, and a conduit 84 made of a flexible pipe that guides the back pressure of the pressure sensor 74 out of the casing 4. Are connected, their end portions are guided above the casing 4, and their end portions are open to the outside air. According to such a configuration, the back pressure of the pressure sensor 74 can be released to the outside air without any restriction on the mounting position of the pressure sensor 74, and the influence of fluctuations in the internal pressure in the casing 4 can be reliably avoided. The water level can be detected with high accuracy.
[0030]
The conduit 84 for guiding the back pressure of the pressure sensor 74 to the outside of the casing 4 may be guided into the flue 17 and discharged to the outside through the exhaust port 18 or 20 as shown in FIG. As shown in FIG. 6, it may be discharged to the outside air from the exhaust port 18 or 20 side.
[0031]
In the embodiment, the conduit 84 is used as a means for guiding the back pressure, but the conduit 84 can be omitted. For example, as shown in FIG. 7, a pressure detection chamber 243 that avoids fluctuations in the internal pressure in the casing 4 is formed on the inner surface side of the casing 4 that passes through the return pipe 60 that is a part of the circulation path 58. The pressure detection chamber 243 is open to the atmosphere with a through hole 244 formed in the casing 4. If a pressure sensor 74 as a water level detection device is installed in the pressure detection chamber 243, the back pressure port 136 (FIG. 2) of the pressure sensor 74 can be opened to the atmosphere through the pressure detection chamber 243, and the inside of the casing 4 The influence of the internal pressure fluctuation can be avoided. In this case, the back pressure port 136 of the pressure sensor 74 may be connected to a through hole 244 formed in the casing 4 so as to be opened to the atmosphere. Further, the same effect can be expected even when the through hole 144 of the cover 142 of the pressure sensor 74 shown in FIG. 2 is matched with the through hole 244 of the casing 4 and the back pressure port 136 is opened to the atmosphere through the cover 142.
[0032]
Moreover, although the Example demonstrated the case where a pressure sensor was installed as a water level detection apparatus of bathtub water, as long as this invention is a pressure sensor installed in the enclosed space with a pressure fluctuation, what kind of The present invention can also be applied to the form and is not limited to the embodiment.
[0033]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
a If a pressure sensor is installed in the casing with internal pressure fluctuation, the back pressure can be released to the atmosphere etc. through the pipe line, so that the pressure detection accuracy is improved without being affected by the internal pressure fluctuation in the casing. be able to.
b Even if a pressure sensor is installed in a casing in which a device that causes fluctuations in internal pressure, such as a hot water supply device, is installed, the detection accuracy of the water level can be increased.
c The detection accuracy of the bathtub water level can be improved and high-quality water level control can be realized.
[Brief description of the drawings]
FIG. 1 is a piping configuration diagram showing a bath water heater that is an embodiment of a pressure sensor , a water level detection device, and a hot water supply system of the present invention.
FIG. 2 is a longitudinal sectional view showing an embodiment of a pressure sensor of the present invention.
FIG. 3 is a block diagram showing a control device for a bath water heater.
FIG. 4 is a partial cross-sectional view showing a bath water heater that is a specific embodiment of the pressure sensor , water level detection device, and hot water supply system of the present invention.
FIG. 5 is a piping configuration diagram showing a bath water heater which is another embodiment of the pressure sensor , water level detection device and hot water supply system of the present invention.
FIG. 6 is a partial cross-sectional view showing a bath water heater that is another specific example of the pressure sensor , water level detection device, and hot water supply system of the present invention.
FIG. 7 is a partially enlarged view showing another embodiment of the pressure sensor , water level detection device and hot water supply system of the present invention.

Claims (6)

A pressure sensor installed in a casing with internal pressure fluctuation,
A pressure guiding pipe portion that is connected to a pipe that allows water to flow and guides water pressure from the pipe side;
A cylindrical portion to be inserted into the pressure guiding tube portion is provided on one surface side, a protruding portion is provided on the other surface side, a back pressure port that is inserted through the cylindrical portion side is provided on the protruding portion, and is fixed to the pressure guiding tube portion . A sensor frame ;
A support base that is surrounded by the cylinder portion of the sensor frame and is installed in the sensor frame, and has a through hole having a smaller diameter than the back pressure port, and the through hole is inserted through the back pressure port and the tube side. When,
A sensor element that is supported by the support base, is installed with the pressure receiving surface facing the inside of the pressure guiding tube portion, and back pressure is released to the atmosphere by the through hole and the back pressure port ,
A pressure guiding gel material that is installed in the cylindrical portion of the sensor frame and covers the pressure receiving surface of the sensor element;
An air layer formed between the water introduced into the pressure guiding tube portion and the pressure guiding gel material, and causing the pressure of the water to act on the pressure receiving surface of the sensor element ;
A pressure sensor comprising:   The pressure sensor according to claim 1, further comprising a conduit that opens back pressure of the sensor element to the outside of the casing. A water level detection device for detecting a water level in the container through a pipe line connected to a container for storing water,
A cylindrical portion to be inserted into the pressure guiding tube portion is provided on one surface side, a protruding portion is provided on the other surface side, a back pressure port that is inserted through the cylindrical portion side is provided on the protruding portion, and is fixed to the pressure guiding tube portion . A sensor frame ;
A support base that is surrounded by the cylinder portion of the sensor frame and is installed in the sensor frame, and has a through hole having a smaller diameter than the back pressure port, and the through hole is inserted through the back pressure port and the tube side. When,
A sensor element that is supported by the support base, is installed with the pressure receiving surface facing the inside of the pressure guiding tube portion, and back pressure is released to the atmosphere by the through hole and the back pressure port ,
A pressure guiding gel material that is installed in the cylindrical portion of the sensor frame and covers the pressure receiving surface of the sensor element;
An air layer formed between the water introduced into the pressure guiding tube portion and the pressure guiding gel material, and causing the pressure of the water to act on the pressure receiving surface of the sensor element ;
A water level detection device comprising:   The water level detection device according to claim 3, wherein the container is a bathtub.   The water level detection device according to claim 3, further comprising a conduit for releasing the back pressure of the sensor element to the outside of the casing. A hot water supply system for detecting a water level through a pipe line connected to a bathtub,
A cylindrical portion to be inserted into the pressure guiding tube portion is provided on one surface side, a protruding portion is provided on the other surface side, a back pressure port that is inserted through the cylindrical portion side is provided on the protruding portion, and is fixed to the pressure guiding tube portion . A sensor frame ;
A support base that is surrounded by the cylinder portion of the sensor frame and is installed in the sensor frame, and has a through hole having a smaller diameter than the back pressure port, and the through hole is inserted through the back pressure port and the tube side. When,
A sensor element that is supported by the support base, is installed with the pressure receiving surface facing the inside of the pressure guiding tube portion, and back pressure is released to the atmosphere by the through hole and the back pressure port ,
A pressure guiding gel material that is installed in the cylindrical portion of the sensor frame and covers the pressure receiving surface of the sensor element;
An air layer formed between the water introduced into the pressure guiding tube portion and the pressure guiding gel material, and causing the pressure of the water to act on the pressure receiving surface of the sensor element ;
The water supply system characterized by detecting the water level of the said bathtub with the said sensor element.

Images