Water heater

Abstract

To provide a water heater capable of opening a tapping side drain plug using a water supply side drain plug as a tool, in a state of removing the water supply side drain plug.SOLUTION: In a water heater comprising: a drain plug 5 for draining water, the water supply side drain plug 5 provided in at least a water supply passage; and a tapping side drain plug provided in a tapping passage, an outward end part of a water supply side drain plug and an outward end part of the tapping side drain plug are respectively provided with first and second engagement parts 8 which can engage with each other, and with the water supply side drain plug removed from the water heater, the first engagement part of the water supply side drain plug is engaged with the second engagement part of the tapping side drain plug and rotated to open the tapping side drain plug.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an improvement in the structures of a water supply side drain cock and a hot water supply side drain cock of a water heater.

Background Art

[0002] A drain cock for draining water is provided respectively on a water supply fitting at the upstream end of a water supply passage provided in a water heater and a hot water supply fitting at the downstream end of a hot water supply passage. When freezing of the water heater is predicted in winter, the water supply side drain cock and the hot water supply side drain cock are opened to drain water from the water supply passage and the hot water supply passage to prevent freezing. The water supply fitting and the hot water supply fitting are equipped in a state of protruding to the lower surface side of the bottom plate of the exterior case of the water heater.

[0003] The water supply side drain cock is made of synthetic resin and has a structure in which a short cylindrical operation part is operated by hand. The hot water supply side drain cock is made of metal, and a pressure relief valve is incorporated inside a cylindrical operation part with a knurled surface of this hot water supply side drain cock, and a jet outlet of this pressure relief valve opens at the tip of the operation part.

[0004] In addition, in the water draining device for an engine cooling system described in Patent Document 1, a drain cock is attached to the middle part of a water draining pipe of the engine cooling system, and this drain cock automatically holds the closed valve position when the oil pressure of the lubricating oil does not decrease, and automatically becomes the open valve position when the oil pressure decreases.

[0005] The drain cock for a water heater described in Patent Document 2 is interposed in the middle of a drain pipe of the water heater. A packing and a piston for opening and closing a drain port are biased toward the closed valve side by a spring, and when the internal pressure of the tank of the water heater rises, it opens against the biasing force of the spring to release the internal pressure, and it can also be opened when the operation knob is manually operated.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Since the hot water outlet side drain plug is made of metal, it becomes stuck when not rotated for a long time, and in many cases, it is not easy to open the plug even when manually rotating the cylindrical operating part with a knurled surface when opening the plug.

[0008] An object of the present invention is to provide a hot water supply apparatus that can open a hot water outlet side drain plug using a water supply side drain plug as a tool with the water supply side drain plug removed. [Means for Solving the Problems]

[0009] The hot water supply apparatus according to claim 1 is a drain plug for draining water, and in a hot water supply apparatus including at least a water supply side drain plug provided in a water supply passage and a hot water outlet side drain plug provided in a hot water outlet passage, first and second engaging portions that can engage with each other are provided at outer ends of the water supply side drain plug and the hot water outlet side drain plug, respectively. With the water supply side drain plug removed from the hot water supply apparatus, the first engaging portion of the water supply side drain plug is engaged with the second engaging portion of the hot water outlet side drain plug and rotated to perform an operation of opening the hot water outlet side drain plug.

[0010] According to the above configuration, with the water supply side drain plug removed from the hot water supply apparatus, the first engaging portion provided at the outer end of the water supply side drain plug is engaged with the second engaging portion provided at the outer end of the hot water outlet side drain plug and rotated to perform an operation of opening the hot water outlet side drain plug. Therefore, the water supply side drain plug can be utilized as a tool to perform an operation of opening the hot water outlet side drain plug.

[0011] The invention according to claim 2 is characterized in that, in the invention according to claim 1, the hot water outlet side drain plug also functions as a pressure safety valve that releases the internal water pressure to the outside when the water pressure in the water heater exceeds a predetermined value. According to the above configuration, since the hot water outlet side drain plug also functions as a pressure safety valve, the number of parts can be reduced and the overall structure can be made small.

[0012] The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the first and second engaging portions engage with each other with the axes of the water inlet side drain plug and the hot water outlet side drain plug orthogonal to each other. According to the above configuration, when rotating the first engaging portion to rotate the second engaging portion, the lever length can be increased to improve the rotational operability.

Effects of the Invention

[0013] As described above, the present invention exhibits various operational effects.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0015] Embodiments for carrying out the present invention will be described with reference to the drawings. As shown in Fig. 1, a water supply fitting 3 connected to the water supply passage and a hot water outlet fitting 4 connected to the hot water outlet passage are provided so as to project downward from the bottom plate 2 of the exterior case of the water heater 1. Although other components are mounted on the bottom plate 2 in addition to the water supply fitting 3 and the hot water outlet fitting 4, they are not directly related to the present invention and thus are not shown in the drawings.

[0016] As shown in Figs. 2 and 3, a water supply side drain plug 5 is screwed into the middle section of the water supply fitting 3. The water supply side drain plug 5 is provided in a state of protruding rightward in Fig. 1 from the middle section of the water supply fitting 3, and its axis A is formed horizontally and in the left-right direction.

[0017] An intake filter 6 is attached to the water supply side drain plug 5 to collect dust and the like contained in the city water. An operation portion 7 having a square outer shape is integrally formed at the outer end portion of the water supply side drain plug 5 of the water supply fitting 3. The four surfaces on the outer peripheral side of the operation portion 7 are each formed into a curved surface slightly recessed toward the axis side. This is to make it easier to grip with the fingers when performing a rotation operation. Note that the outer shape of the operation portion 7 is not limited to a square, and may be a pentagon or a hexagon.

[0018] In the lower half portion of the operation portion 7 in Fig. 2, there is formed a square recess 8a as a first engaging portion 8, which is open to the outer side (the tip side of the axis A) and downward and orthogonal to the axis A.

[0019] As shown in Fig. 3, the internal passage of the water supply fitting 3 is blocked by an O-ring attached to the tip of the water supply side drain plug 5. By rotating the water supply side drain plug 5, the water supply side drain plug 5 can move outward to open the valve. Further, by rotating the water supply side drain plug 5, the drain plug 5 can be removed from the water supply fitting 3 as shown in Fig. 4.

[0020] As shown in Figs. 5 and 6, a hot water outlet side drain plug 10 is incorporated in the middle section of the hot water outlet fitting 4. The hot water outlet side drain plug 10 is provided in a state of protruding slightly forward and leftward in Fig. 1 from the middle section of the hot water outlet fitting 4, and its axis B is formed horizontally and slightly forward and leftward.

[0021] On the hot water outlet drain plug 10 on the hot water outlet side of the hot water outlet fitting 4, a cylindrical operation part 11 with a knurled surface is integrally formed. At the center of the outer end of the operation part 11, a square columnar convex part 12a as the second engaging part 12, which can engage with the first engaging part 8, is formed. The operation part 11 is attached to the hot water outlet fitting 4 by screwing.

[0022] The hot water outlet side drain plug 10 has a pressure safety valve 13 (pressure relief valve) that releases the internal water pressure to the outside when the internal water pressure exceeds a predetermined value due to water hammer or the like. This pressure safety valve 13 has a spring accommodation chamber 14 inside the operation part 11, a compression spring 15 accommodated in this spring accommodation chamber 14, a communication passage 16 formed at the inner end of the operation part 11, and a valve body 17 that is accommodated in the spring accommodation chamber 14 so as to be able to close the communication passage 16 and is pressed by the compression spring 15. A backflow prevention valve 18 is installed inside the hot water outlet fitting 4. This backflow prevention valve 18 has a valve body 19, a cylindrical part 20, a compression spring 21, and the like.

[0023] An annular passage 23 is formed on the outer peripheral side of the middle part of the cylindrical body 22. This annular passage 23 communicates with the communication passage 16, and the internal passage of the cylindrical body 22 communicates with the annular passage 23 through a plurality of openings 24 formed in the cylindrical body 22. When the water pressure inside the hot water outlet fitting 4 rises abnormally, the valve body 17 of the pressure safety valve 13 is opened by the water pressure, and the water pressure in the spring accommodation chamber 14 is released to the outside through an opening hole 25 formed in the operation part 11 and an opening hole 26 formed in the hot water outlet fitting 4.

[0024] When opening the hot water outlet side drain plug 10 of the hot water outlet fitting 4 to prevent freezing, after removing the water supply side drain plug 5 from the water supply fitting 3, the axis A of the water supply side drain plug 5 is made perpendicular to the horizontal axis B of the hot water outlet side drain plug 10, and the first engaging part 8 is engaged with the second engaging part 12. By rotating the hot water outlet side drain plug 10 counterclockwise, drainage from the hot water outlet fitting 4 can be achieved.

[0025] Next, the operation and effects of the hot water supply device 1 described above will be described. With the water supply side drain cock 5 removed from the water heater 1, by engaging the first engaging portion 8 provided at the outer end of the water supply side drain cock 5 with the second engaging portion 12 provided at the outer end of the hot water supply side drain cock 10 and rotating it, the opening operation of the hot water supply side drain cock 10 is configured to be performed. Therefore, the water supply side drain cock 5 can be utilized as a tool to perform the opening operation of the hot water supply side drain cock 10.

[0026] In order to make the hot water supply side drain cock 10 also function as a pressure safety valve, the number of parts can be reduced, and the overall structure can be made compact.

[0027] The first and second engaging portions 8 and 12 engage with each other with the axes A and B of the water supply side drain cock 5 and the hot water supply side drain cock 10 orthogonal to each other. Therefore, the lever length when rotating the first engaging portion 8 to rotate the second engaging portion 12 can be increased to improve the rotational operability. Still, as a modified form, the axis B of the hot water supply side drain cock 10 of the hot water supply fitting 4 may be oriented in the front-rear direction, and the hot water supply side drain cock 10 may be arranged so as to be located above the hot water supply fitting 4 in FIG. 1.

[0028] The above embodiments are merely examples, and those skilled in the art can implement them in various modified forms by adding various changes to the respective structural parts of the above embodiments.

Explanation of Reference Numerals

[0029] 1 Water heater 3 Water supply fitting 4 Hot water supply fitting 5 Water supply side drain cock 8 First engaging portion 10 Hot water supply side drain cock 12 Second engaging portion 13 Pressure safety valve A,B Axes

Claims

1. A drain cock for draining water, in a water heater comprising at least a water supply side drain cock provided in a water supply passage and a hot water outlet side drain cock provided in a hot water outlet passage, outer ends of the water supply side drain cock and the hot water outlet side drain cock are respectively provided with first and second engaging portions that can engage with each other, a water heater, characterized in that, with the water supply side drain cock removed from the water heater, the first engaging portion of the water supply side drain cock is engaged with the second engaging portion of the hot water outlet side drain cock and rotated to open the hot water outlet side drain cock.

2. The water heater according to claim 1, characterized in that the hot water outlet side drain cock also functions as a pressure safety valve that releases internal water pressure to the outside when the water pressure in the water heater exceeds a predetermined value.

3. The water heater according to claim 1 or 2, characterized in that the first and second engaging portions engage with each other with the axes of the water supply side drain cock and the hot water outlet side drain cock perpendicular to each other.

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