Hot water filling control device

Abstract

To promote drainage from between a filter and a check valve of a hot water filling control device.SOLUTION: A hot water outlet passageway that leads hot water from the hot water supply device is branched at a branching section into a hot water supply passageway having a valve opening means and a hot water filling passageway 24 that leads hot water to the bathtub, and a solenoid valve is provided in the hot water filling passageway. A filter 33 is provided on the branching section side of the solenoid valve, and a check valve is provided on the bathtub side of the solenoid valve. The filter is then installed in a vertical passageway section 24v that is disposed in a substantially vertical direction in the hot water filling passageway. This filter has planar filter sections 40a, 41 that are inscribed substantially horizontally in the vertical passageway, and cylindrical filter sections 40b, 42 whose axes are disposed substantially vertically within the vertical passageway, and the upper end side of the cylindrical filter section is joined to the planar filter section, while the lower end side of the cylindrical filter section is left open. As a result, the lower surface of the planar filter section is divided into an inside and an outside by the upper end of the cylindrical filter section.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a hot water filling control device that controls hot water filling performed by supplying hot water from a water heater to a bathtub. Specifically, it relates to a technique for draining water from the hot water filling control device as the water heater is drained.

Background Art

[0002] In a system that fills a bathtub with hot water generated by a water heater, a hot water filling control device for controlling hot water filling is generally provided between the water heater and the bathtub. This hot water filling control device includes a solenoid valve, a filter, a check valve, and the like. The solenoid valve can open and close a hot water filling passage that guides hot water to the bathtub. Hot water filling starts when the solenoid valve opens and stops when the solenoid valve closes. The filter is provided upstream (on the water heater side) of the solenoid valve and removes foreign substances mixed in the hot water from the water heater. The check valve is provided downstream (on the bathtub side) of the solenoid valve and is biased in the valve closing direction to close the hot water filling passage. When the pressure of the hot water supplied from the water heater exceeds a predetermined valve opening pressure due to the opening of the solenoid valve, the check valve opens to allow the hot water to pass through. On the other hand, when the pressure of the hot water supplied from the water heater drops below the valve opening pressure due to reasons such as water cut-off during hot water filling, the check valve closes, so it is possible to prevent the hot water from flowing back from the bathtub side to the water heater side through the hot water filling passage.

[0003] Also, in such a hot water filling control device, it has been proposed to branch an atmosphere release passage from the hot water filling passage on the downstream side of the check valve and provide an atmosphere release valve in this atmosphere release passage (Patent Document 1). The atmosphere release valve is biased in the valve opening direction by a valve opening spring and is in a closed state by resisting the biasing force of the valve opening spring by receiving the pressure of the make-up water supplied to the water heater. When the pressure of the make-up water decreases due to water cut-off or the like, the atmosphere release valve opens by the biasing force of the valve opening spring, and the hot water on the downstream side of the check valve is discharged and replaced with the inflowing air. Therefore, even if the closing of the check valve is incomplete, it is possible to prevent the backflow of hot water from the bathtub side to the water heater side. Further, since the atmosphere release valve opens as the supply of the make-up water is stopped also during the draining of the water heater, it can be used for draining the downstream side of the check valve.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the hot water filling control device having the above-described configuration, there was a problem that hot water between the filter and the check valve was difficult to drain and remained during water drainage. This is due to the following reasons. First, during water drainage, even if the solenoid valve is opened, the check valve remains closed, and atmospheric pressure does not act on the hot water from the downstream side to the upstream side of the check valve. On the other hand, when the hot water on the upstream side (hot water supply device side) of the filter drains with the water drainage of the hot water supply device, atmospheric pressure acts on the hot water from the upstream side to the downstream side of the filter. Also, due to the fine mesh of the filter, surface tension of water is generated and the water surface is maintained, making it difficult for air to enter. For this reason, between the filter and the check valve, even if the hot water tries to flow out from the filter side, since there is no inflow of replaced air, a negative pressure is generated, and the weight of the hot water is supported by this negative pressure and the atmospheric pressure acting from the upstream side of the filter. If the hot water remains trapped between the filter and the check valve in this way, there is a risk of damage due to freezing expansion in winter.

[0006] This invention has been made in response to the above-described problems in the prior art, and an object thereof is to provide a technology capable of promoting water drainage from between the filter and the check valve of the hot water filling control device.

Means for Solving the Problems

[0007] In order to solve the above-described problems, the hot water filling control device of the present invention adopts the following configuration. That is, In a hot water filling control device that controls hot water filling performed by supplying hot water from a hot water supply device to a bathtub, a branch portion that branches a hot water outlet passage for guiding hot water from the hot water supply device into a hot water supply passage having an opening means that is opened during water drainage of the hot water supply device and a hot water filling passage for guiding hot water to the bathtub, a solenoid valve that opens and closes the hot water filling passage, a filter provided on the branch portion side with respect to the solenoid valve, which removes foreign substances mixed in the hot water from the hot water supply device, A check valve provided on the bathtub side of the electromagnetic valve, biased in a direction to close the hot water filling passage, and opening when the pressure of the hot water supplied from the water supply device exceeds a predetermined valve opening pressure due to the opening of the electromagnetic valve, and closing when the pressure is below the valve opening pressure and includes The filter is installed in a vertical passage portion arranged in a substantially vertical direction in the hot water filling passage, The filter has a mesh-like planar filter portion that is substantially horizontally inscribed in the vertical passage portion, and a mesh-like cylindrical filter portion that is cylindrical with its axis arranged in a substantially vertical direction within the vertical passage portion, with the upper end side joined to the planar filter portion and the lower end side open and has the lower surface of the planar filter portion is partitioned into an inner side and an outer side by the upper end of the cylindrical filter portion which is characterized by this.

[0008] In such a hot water filling control device of the present invention, when the opening means is opened along with the draining of the water supply device, the hot water in the hot water filling passage is discharged from the opening means and replaced with air flowing in from the opening means. In particular, on the upstream side (branch portion side) of the planar filter portion of the vertical passage portion where the filter is installed, the hot water outside the cylindrical filter portion drains first and is replaced with air. At this time, at the portion of the planar filter portion located outside the cylindrical filter portion (hereinafter referred to as the outer filter portion), the surface tension of the water is generated by the mesh to maintain the water surface, making it difficult for air to enter, and the hot water on the downstream side (electromagnetic valve side) is supported by the atmospheric pressure acting from the upstream side of the outer filter portion. Also, in the cylindrical filter portion, since the surface tension of the water is generated to maintain the water surface, it is difficult for air to enter from the outside to the inside of the cylindrical filter portion, and the atmospheric pressure acts from the outside of the cylindrical filter portion, so the hot water does not flow out from the inside to the outside of the cylindrical filter portion. And as long as the lower end of the cylindrical filter portion is immersed in the hot water, the hot water remains inside the cylindrical filter portion, and the draining of the inside is delayed compared to the outside of the cylindrical filter portion. When the lower end of the cylindrical filter portion emerges from the hot water, the hot water inside quickly drains from the open lower end of the cylindrical filter portion and is replaced with air.

[0009] In addition, the air flowing in from the opening / closing means vaporizes inside the hot water flowing toward the opening / closing means and rises against the flow of the hot water. Then, when bubbles enter the lower end of the cylindrical filter part immersed in the hot water, they pass through the inside of the cylindrical filter part and collide with the part (hereinafter referred to as the inner filter part) located inside the cylindrical filter part in the planar filter part. The size of these bubbles is selected by the inner diameter of the lower end of the cylindrical filter part, and relatively small bubbles corresponding to the inner diameter collide with the inner filter part substantially perpendicularly, overcoming the surface tension of the water and passing through the inner filter part. As a result, the hot water on the downstream side of the inner filter part is replaced by the bubbles (air) that have entered the downstream side, and the hot water on the downstream side of the inner filter part flows out to the upstream side, so that the draining between the filter and the check valve can be promoted.

[0010] In the branch part of the hot water filling control device of the present invention described above, the hot water supply passage is joined in a substantially vertical direction below the vertical passage part of the hot water filling passage, and the hot water discharge passage is joined in a substantially horizontal direction. The lower end of the filter part may be located in the hot water supply passage below the branch part.

[0011] In this way, when the opening / closing means is opened along with the draining of the hot water supply device, the hot water in the hot water discharge passage is discharged from the opening / closing means through the branch part and the hot water supply passage. Generally, the time required for discharging the hot water in the hot water discharge passage is longer than the time required for discharging the hot water in the hot water filling passage (vertical passage part) upstream of the planar filter part. Therefore, if the lower end of the cylindrical filter part is arranged in the hot water supply passage, the state in which the lower end of the cylindrical filter part is immersed in the hot water can be maintained longer than when it is arranged in the vertical passage part. As a result, the chance of bubbles entering the lower end of the cylindrical filter part immersed in the hot water increases, so that the number of bubbles passing through the inner filter part and entering the downstream side increases, and the draining between the filter and the check valve can be further promoted.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0013] FIG. 1 is an explanatory diagram showing the overall configuration of the hot water filling system 1 including the hot water filling control device 30 of this embodiment. As shown in the figure, the hot water filling system 1 includes a hot water supply device 10 that generates hot water, a bathtub 2 that stores hot water, a hot water filling control device 30 that controls hot water filling between the hot water supply device 10 and the bathtub 2, and the like.

[0014] The hot water supply device 10 includes a combustion chamber 12 having a burner 11 that burns fuel gas, and fuel gas is supplied to the burner 11 through a gas passage 13. Further, a combustion fan 14 is connected to the combustion chamber 12, and combustion air is sent to the burner 11 by the combustion fan 14.

[0015] Above the burner 11, a heat exchanger 15 is provided. The combustion exhaust gas generated by the combustion in the burner 11 passes through the heat exchanger 15 and is discharged to the outside of the water heater 10. On the upstream side of the heat exchanger 15, a water supply passage 16 is connected, and make-up water is supplied to the heat exchanger 15 through the water supply passage 16. The water supply passage 16 is provided with a stop valve 17 for stopping the supply of make-up water to the water heater 10 and a first drain valve 18 that is opened when draining the water heater 10 downstream of the stop valve 17. The make-up water supplied to the heat exchanger 15 in the water supply passage 16 is heated by heat exchange with the combustion exhaust gas and then flows out as hot water into the hot water outlet passage 20.

[0016] The hot water led to the hot water filling control device 30 through the hot water outlet passage 20 connected to the downstream side of the heat exchanger 15 is distributed, as will be described later, via the hot water filling control device 30 to a hot water supply passage 22 that guides the hot water to the hot water supply faucet 21 (so-called calan) and a hot water filling passage 24 that guides the hot water to the bathtub 2. The hot water supply passage 22 is provided with a second drain valve 23 that is opened when draining the water heater 10. Further, the hot water filling control device 30 is connected to a make-up water pressure passage 19 that branches off from the downstream side of the first drain valve 18 of the water supply passage 16. Note that the second drain valve 23 of the present embodiment corresponds to the "valve opening means" of the present invention.

[0017] FIG. 2 is an explanatory diagram conceptually showing the configuration of the hot water filling control device 30 of the present embodiment. As shown in the figure, the hot water filling control device 30 of the present embodiment includes a branching portion 25 that branches a hot water outlet passage 20 that guides hot water from the water heater 10 (heat exchanger 15) into a hot water supply passage 22 connected to the hot water supply faucet 21 and a hot water filling passage 24 connected to the bathtub 2. In the branching portion 25 of the present embodiment, the hot water outlet passage 20 in the substantially horizontal direction branches into a hot water supply passage 22 directed downward in the substantially vertical direction and a hot water filling passage 24 directed upward in the substantially vertical direction. And on the hot water filling passage 24, a hot water filling solenoid valve 31, a flow rate sensor 32, a filter 33, and two check valves (a first check valve 35 and a second check valve 36) are provided.

[0018] The hot water filling solenoid valve 31 can open and close the hot water filling passage 24. The hot water filling starts when the hot water filling solenoid valve 31 is opened, and the hot water filling stops when the hot water filling solenoid valve 31 is closed. A well-known pilot-operated solenoid valve is used for the hot water filling solenoid valve 31 in this embodiment, but a direct-acting solenoid valve may also be used. Since a pilot-operated solenoid valve that utilizes differential pressure generally opens and closes with a smaller force compared to a direct-acting solenoid valve, it is possible to miniaturize the actuator and suppress power consumption. Note that the hot water filling solenoid valve 31 in this embodiment corresponds to the "solenoid valve" of the present invention.

[0019] The flow rate sensor 32 is provided on the upstream side (the hot water supply device 10 side) of the hot water filling solenoid valve 31 and measures the flow rate of the hot water passing through the hot water filling passage 24. The flow rate sensor 32 in this embodiment incorporates an impeller that rotates due to the flow of the hot water in the hot water filling passage 24, and measures the flow rate of the hot water based on the rotation speed of the impeller. Further, a filter 33 is provided on the upstream side of the flow rate sensor 32, and by removing foreign substances mixed in the hot water from the hot water supply device 10 with the filter 33, it is possible to suppress a situation where the flow rate sensor 32 and the hot water filling solenoid valve 31 do not operate normally due to the influence of foreign substances. Note that the details of the filter 33 in this embodiment will be described later with reference to another figure.

[0020] The first check valve 35 and the second check valve 36 are provided in series on the downstream side (bathtub 2 side) of the hot water supply solenoid valve 31. The first check valve 35 located on the hot water supply solenoid valve 31 side among the two check valves includes a valve body 35a that can move to open and close the hot water supply passage 24, and a closing spring 35b that biases the valve body 35a in the closing valve direction to close the hot water supply passage 24. When the pressure of the hot water supplied from the water supply device 10 rises due to the opening of the hot water supply solenoid valve 31 and exceeds a predetermined opening valve pressure, the valve body 35a moves in the opening valve direction against the biasing force of the closing spring 35b, and the first check valve 35 is in an open valve state. Also, the second check valve 36 located on the bathtub 2 side among the two check valves is basically configured in the same way as the first check valve 35 and is biased in the closing valve direction, and when the pressure of the hot water supplied from the water supply device 10 exceeds a predetermined opening valve pressure due to the opening of the hot water supply solenoid valve 31 and the first check valve 35, it is in an open valve state. In this way, when the first check valve 35 and the second check valve 36 are in an open valve state and the hot water passes through, the bathtub 2 is filled with hot water. Note that the first check valve 35 in this embodiment corresponds to the "check valve" of the present invention.

[0021] On the other hand, when the pressure of the hot water supplied from the water supply device 10 decreases below a predetermined opening valve pressure due to reasons such as water cut during hot water filling, the valve body 35a is pushed back in the closing valve direction by the biasing force of the closing spring 35b, and the first check valve 35 is in a closed valve state. Also, the second check valve 36 similarly becomes in a closed valve state, thereby preventing the backflow of the hot water from the bathtub 2 side to the water supply device 10 side. By installing the two check valves (the first check valve 35 and the second check valve 36) in series in this way, the effect of preventing the backflow of the hot water can be enhanced compared to the case where there is only one check valve.

[0022] Also, an atmosphere release passage 37 is provided which branches off from the hot water filling passage 24 between the first check valve 35 and the second check valve 36, and an atmosphere release valve 38 is installed to open and close this atmosphere release passage 37. The atmosphere release valve 38 is partitioned into a primary chamber 38b and a secondary chamber 38c by a diaphragm 38a. An upper water pressure passage 19 branched from the water supply passage 16 is connected to the primary chamber 38b, and the atmosphere release passage 37 is connected to the secondary chamber 38c. In addition to a valve body 38d supported by the diaphragm 38a and an opening spring 38e that biases the diaphragm 38a and the valve body 38d toward the primary chamber 38b provided in the secondary chamber 38c, a discharge passage 38f that is open to the atmosphere is connected.

[0023] When water is normally supplied to the water heater 10, compared to the water pressure (primary pressure) of the upper water in the upper water pressure passage 19 branched from the water supply passage 16 upstream of the heat exchanger 15, the hot water pressure (secondary pressure) of the atmosphere release passage 37 branched from the hot water filling passage 24 through the heat exchanger 15, the filter 33, the flow sensor 32, the hot water filling solenoid valve 31, and the first check valve 35 has decreased due to pressure loss. Since the primary pressure is higher than the secondary pressure by a specified value or more and resists the biasing force of the opening spring 38e, the diaphragm 38a and the valve body 38d are pushed into the secondary chamber 38c side, so the atmosphere release valve 38 is in a closed state. On the other hand, when water supply to the water heater 10 stops due to water cut-off or the like and the primary pressure decreases and the pressure difference with respect to the secondary pressure becomes less than the specified value, the diaphragm 38a and the valve body 38d are pushed back toward the primary chamber 38b side by the biasing force of the opening spring 38e, and the atmosphere release valve 38 is in an open state. Therefore, the hot water between the first check valve 35 and the second check valve 36 is discharged from the discharge passage 38f and replaced with the inflowing air. Accordingly, even if the closing of the first check valve 35 or the second check valve 36 is incomplete, backflow of hot water from the bathtub 2 side to the water heater 10 side can be prevented.

[0024] In addition, the atmosphere release valve 38 opens when the water supply to the water supply passage 16 is stopped by closing the stop valve 17 during draining of the water heater 10, so that the hot water between the first check valve 35 and the second check valve 36 in the hot water filling passage 24 can be discharged and used for draining the hot water filling control device 30. However, in the conventional hot water filling control device 30, hot water may remain without being drained upstream of the first check valve 35 in the hot water filling passage 24 during draining, and there is a risk of damage due to freezing and expansion of the remaining hot water in winter. Hereinafter, the configuration adopted in the hot water filling control device 30 of this embodiment for promoting draining will be described. As a preparation therefor, draining in the conventional hot water filling control device 30 will be described first.

[0025] FIG. 3 is an explanatory diagram showing the state of draining in the conventional hot water filling control device 30. First, FIG. 3(a) shows the state before draining, and the hatched portion in the figure indicates that there is hot water. It is assumed that before draining, the hot water in the bathtub 2 is drained, and thus the hot water in the hot water filling passage 24 on the downstream side (bathtub 2 side) of the second check valve 36 is also drained. Since hot water filling is not performed during draining, the hot water filling solenoid valve 31 is in a closed state, and accordingly, the first check valve 35 and the second check valve 36 are also in a closed state. Further, since the pressure of the incoming water is applied to the atmosphere release valve 38 via the incoming water pressure passage 19, the atmosphere release valve 38 is in a closed state. Therefore, the hot water discharge passage 20, the hot water supply passage 22, the hot water filling passage 24 upstream of the second check valve 36, and the atmosphere release passage 37 are filled with hot water.

[0026] When draining water, after the operator closes the stop valve 17 of the water supply passage 16 to stop the supply of city water, the first drain plug 18 and the second drain plug 23 are opened (see Fig. 1). Then, as shown in Fig. 3(b), the city water in the city water pressure passage 19 is discharged from the first drain plug 18, and the pressure of the city water is no longer applied to the atmosphere release valve 38, so the atmosphere release valve 38 opens. As a result, the hot and cold water between the first check valve 35 and the second check valve 36 is discharged from the atmosphere release valve 38 and replaced with the air that has flowed in. In addition, the hot and cold water in the hot water outlet passage 20, the hot water supply passage 22, and the heat insulation passage 24 is discharged from the second drain plug 23. Incidentally, the hot and cold water can also be discharged by opening the hot water supply tap 21 instead of the second drain plug 23.

[0027] However, in the conventional heat insulation control device 30 in which a general filter 34 is installed in the heat insulation passage 24 on the upstream side of the flow rate sensor 32, the hot and cold water between the filter 34 in the heat insulation passage 24 and the first check valve 35 remains without being discharged. That is, for the section from the filter 34 to the first check valve 35, even if the heat insulation solenoid valve 31 is opened, the first check valve 35 remains closed, and atmospheric pressure does not act on the hot and cold water from the downstream side to the upstream side of the first check valve 35, and air does not enter. On the other hand, since the hot and cold water in the heat insulation passage 24 has escaped on the upstream side of the filter 34, atmospheric pressure acts on the hot and cold water from the upstream side to the downstream side of the filter 34. In addition, the fine mesh of the filter 34 generates the surface tension of water and keeps the water surface, making it difficult for air to enter. For this reason, between the filter 34 and the first check valve 35, even if the hot and cold water tries to flow out from the filter 34 side, there is no inflow of the replacing air, so a negative pressure is generated. The weight of the hot and cold water is supported by this negative pressure and the atmospheric pressure acting from the upstream side of the filter 34. As a result, the hot and cold water remains trapped between the filter 34 and the first check valve 35.

[0028] FIG. 4 is a perspective view showing the configuration of the filter 33 employed in the hot water filling control device 30 of this embodiment to promote draining. First, FIG. 4(a) shows the structure of the frame body 40 that forms the framework of the filter 33 of this embodiment. The frame body 40 of this embodiment, which is made of resin, has an annular portion 40a formed in an annular shape and a cylindrical portion 40b formed in a slender cylindrical shape with a smaller diameter than the annular portion 40a. The open upper end of the cylindrical portion 40b is located inside the annular portion 40a, and the annular portion 40a and the cylindrical portion 40b are connected in the radial direction by a plurality (four in the illustrated example) of spokes 40c. These spokes 40c are arranged at predetermined intervals in the circumferential direction, and hot water can pass between the spokes 40c and inside the cylindrical portion 40b.

[0029] On the circumferential surface of the cylindrical portion 40b, a plurality (four in the illustrated example) of axial (vertical direction in the figure) slits 40d are formed at predetermined intervals in the circumferential direction. These slits 40d communicate the inside and outside of the cylindrical portion 40b, and a support column 40e is provided between the slits 40d. Further, at the lower end of the cylindrical portion 40b, an opening 40f opens downward, and a plurality (four in the illustrated example) of convex portions 40g protruding outward in the radial direction are provided at predetermined intervals in the circumferential direction.

[0030] And as shown in FIG. 4(b), in the filter 33 of this embodiment, a mesh-like planar filter 41 is attached to the upper surface of the annular portion 40a of the frame body 40, and the spaces between the spokes 40c inside the annular portion 40a and the open upper end of the cylindrical portion 40b are covered with the planar filter 41. Also, a mesh-like cylindrical filter 42 is attached to the outer circumferential surface of the cylindrical portion 40b, and the slits 40d are covered with the cylindrical filter 42. For the planar filter 41 and the cylindrical filter 42 of this embodiment, a fine-mesh (e.g., 80 mesh) wire mesh is used. Note that the opening 40f at the lower end of the cylindrical portion 40b is open without being covered with a wire mesh. Also, the annular portion 40a and the planar filter 41 of this embodiment correspond to the "planar filter portion" of the present invention, and the cylindrical portion 40b and the cylindrical filter 42 of this embodiment correspond to the "cylindrical filter portion" of the present invention.

[0031] FIG. 5 is a cross-sectional view showing the state in which the filter 33 of this embodiment is installed in the hot water passage 24. The figure represents a cross-section cut along a plane including the center line of the hot water passage 24, and the filter 33 is installed in a portion (vertical passage portion 24v) disposed in a substantially vertical direction in the hot water passage 24. This vertical passage portion 24v can be divided vertically, and has a joint portion 24j in which the convex end portion 24a is inserted into the concave end portion 24b and joined. Then, the annular portion 40a of the filter 33 is sandwiched between the convex end portion 24a and the concave end portion 24b of the joint portion 24j, so that the planar filter 41 is inscribed in the vertical passage portion 24v substantially horizontally, and the axis of the cylindrical filter 42 is arranged in a substantially vertical direction along the center line in the vertical passage portion 24v. Although not shown in FIG. 5, a plurality of convex portions 40g (see FIG. 4(a)) projecting radially outward from the lower end of the cylindrical portion 40b of the filter 33 ensure a space between the inner surface of the vertical passage portion 24v and the cylindrical portion 40b, suppressing the cylindrical filter 42 from tilting significantly.

[0032] The lower surface of the planar filter 41 is partitioned into an inner side and an outer side by the upper end of the cylindrical portion 40b forming the skeleton of the cylindrical filter 42 coming into contact therewith. Hereinafter, the inner portion of the planar filter 41 inside the cylindrical portion 40b may be referred to as the "inner filter 41a", and the outer portion may be referred to as the "outer filter 41b" for distinction.

[0033] The hot water supplied from the water heater 10 through the hot water passage 20 flows through the vertical passage portion 24v from the lower side to the upper side in the figure. Then, the foreign matter is removed when the hot water passing through the outside of the cylindrical filter 42 (cylindrical portion 40b) passes through the outer filter 41b. Also, the foreign matter is removed when the hot water entering from the opening 40f at the lower end of the cylindrical portion 40b and passing through the inside of the cylindrical filter 42 passes through the inner filter 41a. It should be noted that the hot water can also pass through the cylindrical filter 42 and go back and forth between the inside and the outside.

[0034] FIG. 6 is an explanatory diagram showing the state of draining water in the hot water filling control device 30 of this embodiment. The figure shows a longitudinal cross-section inside the vertical passage portion 24v where the filter 33 is installed in the hot water filling passage 24. As described above, when the second drain plug 23 is opened along with the draining of water from the water supply device 10, the hot water in the hot water filling passage 24 is discharged from the second drain plug 23 and is replaced with air flowing in from the second drain plug 23. Upstream (downward in the figure) of the planar filter 41 in the vertical passage portion 24v where the filter 33 is installed, as shown in FIG. 6(a), the hot water outside the cylindrical filter 42 drains first and is replaced with air. At this time, in the outer filter 41b, similar to the conventional general filter 34 described above, fine pores cause the surface tension of water to form and maintain the water surface, making it difficult for air to enter. The atmospheric pressure acting from the upstream side (downward in the figure) of the outer filter 41b supports the hot water on the downstream side (upward in the figure). Also, in the cylindrical filter 42, since the surface tension of water is generated and the water surface is maintained, it is difficult for air to enter from the outside to the inside of the cylindrical filter 42. Due to the atmospheric pressure acting from the outside of the cylindrical filter 42, hot water does not flow out from the inside to the outside of the cylindrical filter 42.

[0035] And as long as the lower end of the cylindrical portion 40b is immersed in the hot water, the hot water remains inside the cylindrical filter 42, and the draining of water inside is delayed compared to the outside of the cylindrical filter 42. Incidentally, when all the hot water outside the cylindrical filter 42 has drained and the lower end of the cylindrical portion 40b is no longer immersed in the hot water (comes out of the hot water), due to the thickness of the cylindrical portion 40b, the influence of the surface tension of water at the opening 40f is small and the water surface breaks. Therefore, the hot water inside the cylindrical filter 42 quickly drains from the opening 40f and is replaced with air.

[0036] Also, although not shown in Fig. 6(a), as shown in Fig. 6(b), the air flowing in from the second drain plug 23 vaporizes inside the hot water flowing toward the second drain plug 23, and the bubbles rise against the flow of the hot water. When the bubbles enter the opening 40f at the lower end of the cylindrical portion 40b immersed in the hot water, the bubbles collide with the inner filter 41a at the upper end through the inside of the cylindrical filter 42. Note that bubbles larger than the inner diameter of the opening 40f do not enter the opening 40f, and the size of the bubbles colliding with the inner filter 41a is selected according to the inner diameter of the opening 40f.

[0037] In this way, relatively small bubbles corresponding to the inner diameter of the opening 40f collide with the inner filter 41a substantially perpendicularly, overcoming the surface tension of the water and passing through the inner filter 41a. As a result, the hot water on the downstream side (upper side in the figure) of the inner filter 41a is replaced by the bubbles (air) that have entered, and the hot water on the downstream side of the inner filter 41a flows out to the upstream side (lower side in the figure), so that the drainage between the filter 33 and the first check valve 35 can be promoted.

[0038] Also, if the bubbles (air) that have passed through the inner filter 41a and entered the downstream side can replace at least some of the hot water between the filter 33 and the first check valve 35, even if the hot water between the filter 33 and the first check valve 35 is not completely discharged and the remaining hot water freezes and expands in winter, it is possible to absorb the expansion with the air replaced by the hot water and suppress damage.

[0039] The hot water control device 30 of the present embodiment described above also has the following modification examples. Hereinafter, the modification examples will be described centering on the points different from the above-described embodiment. In the description of the modification examples, the same components as those in the above-described embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

[0040] FIG. 7 is a longitudinal sectional view showing the installation location of the filter 33 in the hot water filling control device 30 of the modified example. As shown in the figure, in the branch portion 25, the hot water supply passage 22 is joined to the lower side of the vertical passage portion 24v of the hot water filling passage 24 in a substantially vertical direction, and the hot water discharge passage 20 is joined in a substantially horizontal direction. Also, in the filter 33 of the modified example, similar to the above-described embodiment, the flat filter 41 at the upper end is inscribed in the vertical passage portion 24v of the hot water filling passage 24 in a substantially horizontal manner. However, the lower end of the cylindrical portion 40b of the modified example is located in the hot water supply passage 22 below the branch portion 25, rather than in the vertical passage portion 24v.

[0041] As described above, when the second drain plug 23 is opened with the draining of the hot water supply device 10, the hot water in the hot water discharge passage 20 is discharged from the second drain plug 23 through the branch portion 25 and the hot water supply passage 22. Generally, the time required for discharging the hot water in the hot water discharge passage 20 is longer than the time required for discharging the hot water in the hot water filling passage 24 (vertical passage portion 24v) on the upstream side of the flat filter 41. Therefore, if the lower end of the cylindrical portion 40b of the filter 33 is arranged in the hot water supply passage 22, the state where the lower end of the cylindrical portion 40b is immersed in the hot water can be maintained for a longer time compared to the case where it is arranged in the vertical passage portion 24v. As a result, the chance of air bubbles entering the opening 40f at the lower end of the cylindrical portion 40b immersed in the hot water increases, so that the air bubbles passing through the inner filter 41a and entering the downstream side increase, and the draining between the filter 33 and the first check valve 35 can be further promoted.

[0042] Also, in the hot water filling control device 30 of the modified example, the hot water guided from the hot water supply device 10 through the hot water discharge passage 20 to the branch portion 25 during hot water filling may pass through the cylindrical filter 42 and then further pass through the inner filter 41a through the inside of the cylindrical filter 42. In such a case, since the hot water is filtered twice by the cylindrical filter 42 and the inner filter 41a, the mesh of the inner filter 41a may be made coarser than that of the cylindrical filter 42. In this way, the surface tension of the water in the inner filter 41a can be reduced during draining, and the air bubbles can easily pass through the inner filter 41a, which is advantageous for draining between the filter 33 and the first check valve 35.

[0043] The above-described hot water filling control device 30 of the embodiments and modification examples has been described. However, the present invention is not limited to the above-described embodiments and modification examples, and can be implemented in various modes without departing from the gist thereof.

[0044] For example, in the above-described embodiment, the filter 33 was manufactured by combining the resin-made frame body 40 and the wire mesh (the flat filter 41 and the cylindrical filter 42). However, the flat filter 41 and the cylindrical filter 42 are not limited to the wire mesh, and may be formed in a mesh shape from a resin material.

Explanation of Reference Numerals

[0045] 1... hot water filling system, 2... bathtub, 10... hot water supply device, 11... burner, 12... combustion chamber, 13... gas passage, 14... combustion fan, 15... heat exchanger, 16... water supply passage, 17... stop valve, 18... first drain plug, 19... city water pressure passage, 20... hot water outlet passage, 21... hot water supply faucet, 22... hot water supply passage, 23... second drain plug, 24... hot water filling passage, 24a... convex end portion, 24b... concave end portion, 24j... joint portion, 24v... vertical passage portion, 25... branch portion, 30... hot water filling control device, 31... hot water filling solenoid valve, 32... flow sensor, 33... filter, 34... filter, 35... first check valve, 35a... valve body, 35b... closing spring, 36... second check valve, 37... atmosphere release passage, 38... atmosphere release valve, 38a... diaphragm, 38b... primary chamber, 38c... secondary chamber, 38d... valve body, 38e... opening spring, 38f... discharge passage, 40... frame body, 40a... annular portion, 40b... cylindrical portion, 40c... spoke, 40d... slit, 40e... support column, 40f... opening, 40g... convex portion, 41a... flat filter, 41a... inner filter, 41b... outer filter, 42... cylindrical filter.

Claims

1. In a hot water filling control device that controls hot water filling performed by supplying hot water from a water heater to a bathtub, a branch portion that branches an outlet hot water passage that guides hot water from the water heater into a hot water passage having a valve opening means that is opened when the water heater is drained and a hot water filling passage that guides hot water to the bathtub, a solenoid valve that opens and closes the hot water filling passage, a filter provided on the branch portion side of the solenoid valve to remove foreign matter mixed in the hot water from the water heater, a check valve provided on the bathtub side of the solenoid valve, biased in a direction to close the hot water filling passage, and opening when the pressure of the hot water supplied from the water heater exceeds a predetermined valve opening pressure due to the opening of the solenoid valve and closing when it falls below the valve opening pressure are provided, the filter is installed in a vertical passage portion disposed in a substantially vertical direction in the hot water filling passage, the filter has a mesh-like planar filter portion that is substantially horizontally inscribed in the vertical passage portion, and a mesh-like cylindrical filter portion that is cylindrical with its axis disposed in a substantially vertical direction within the vertical passage portion, has its upper end side joined to the planar filter portion, and has its lower end side open, and the lower surface of the planar filter portion is partitioned into an inner side and an outer side by the upper end of the cylindrical filter portion. A hot water filling control device characterized by the above.

2. In the hot water filling control device according to Claim 1, in the branch portion, the hot water passage is joined in a substantially vertical direction below the vertical passage portion of the hot water filling passage, and the outlet hot water passage is joined in a substantially horizontal direction, the lower end of the cylindrical filter portion is located in the hot water passage below the branch portion. A hot water filling control device characterized by the above.

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