Fluid equipment and method for adding freeze crack prevention function to fluid equipment

Abstract

To adjust standard pressure at a start of drainage without dismantling an apparatus.SOLUTION: A fluid apparatus (centrifugal pump 301) comprises: a casing (spiral casing 302) having flow passages (suction flow passage 305, spiral flow passage 309 or the like) for making fluid flow, penetration holes (drain hole 310, gauge holes 311, 312 or the like), and a cock 101 which is connected to the penetration holes, and into which the fluid flows. The cock has an opening part (inlet flow passage 112), a valve 106 for blocking an opening part, and damming up the fluid, and a discharge hole 110 for discharging the fluid to the outside. The cock makes the opening part and the discharge hole communicate with each other by the movement of the valve on the basis of an increase of the pressure of the fluid.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fluid device and a method for adding a freeze crack prevention function to a fluid device. [Background technology]

[0002] In facilities that handle fluids, such as industrial water supply and drainage facilities, and drinking water supply facilities for buildings and condominiums, pumps are essential equipment that can be said to be the core of fluid-related systems. Abnormalities and failures of these pumps should be avoided because they can lead to the collapse of life infrastructure and the stoppage of factory lines. There are various causes of pump abnormalities and failures, one of which is freeze cracking. Freeze cracking is a phenomenon in which the fluid (water) inside the pump freezes and expands due to a drop in outside temperature, putting a lot of pressure on the casing and causing it to break. In particular, pumps are often installed outdoors, making them prone to freeze cracking. Countermeasures against freeze cracking of pumps include freeze prevention operation using inverter control and the use of antifreeze.

[0003] However, the freeze prevention operation by inverter control consumes electricity, and weatherproofing measures are required when the pump is installed outdoors, which increases costs. In addition, it is known that the use of antifreeze has disadvantages such as being basically applicable only to circulation pumps and environmental pollution due to the antifreeze leaking out. Furthermore, in relatively warm regions, fluids do not freeze much, so using antifreeze on a daily basis increases costs. In addition, it is difficult to predict the timing when the fluid will freeze, so it is difficult to take effective measures against freeze cracking. From this perspective, for example, the technology described in Patent Document 1 has been proposed as a technology for preventing freeze cracking. The technology described in Patent Document 1 reduces the occurrence of freeze cracking by using a spring to discharge water to the outside, which corresponds to the pressure increased by freezing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-64224 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional technology described in Patent Document 1, the device must be disassembled in order to adjust the standard pressure for starting drainage. Because the conventional technology described in Patent Document 1 requires a lot of work to make adjustments, it is desirable to be able to adjust the standard pressure for starting drainage without disassembling the device.

[0006] The present invention has been made to solve the above-mentioned problems, and its main object is to provide a fluid equipment that allows the standard pressure for starting drainage to be adjusted without disassembling the equipment, and a method for adding a freeze cracking prevention function to a fluid equipment. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a fluid device comprising: a casing having a flow path for flowing a fluid and a through hole; and a cock connected to the through hole and through which the fluid flows, the cock having an opening, a valve for closing the opening and damming the fluid, and a drain hole for discharging the fluid to the outside, and the opening and the drain hole are connected by moving the valve based on an increase in pressure of the fluid. The valve has a heat insulating member disposed on a surface opposite to the surface in contact with the fluid. , the composition. The present invention also provides a fluid device comprising a casing having a flow path for flowing a fluid and a through hole, and a cock connected to the through hole and into which the fluid flows through the through hole, the cock having an opening, a valve for blocking the opening and damming the fluid, and a drain hole for discharging the fluid to the outside, the opening and the drain hole being connected by the valve moving based on an increase in pressure of the fluid, the cock further having an elastic portion connected to the valve and an adjustment portion for adjusting the tension of the elastic portion, the elastic portion being a spring, the adjustment portion being fluid injected into an injection plug, and the pressure of the fluid being adjusted according to the degree of injection of the fluid, thereby moving an inner plate located in the upper part of the spring, controlling the tension of the spring, and adjusting the force applied to the valve. The present invention also relates to a fluid device comprising a casing having a flow path therein for flowing a fluid, a plug attached to the casing so as to seal the flow path, and a cock attached to the plug, wherein the cock has a drill portion having a tip inlet at its tip for allowing the fluid to flow into the interior, a discharge hole for discharging the fluid to the outside, an opening formed from the tip inlet to the discharge hole, and a valve disposed inside the opening to block the opening and stop the fluid, and the plug has a hole formed in the drill portion of the cock and the cock attached thereto so that the tip inlet of the cock reaches the flow path inside the casing.

[0008] The present invention also provides a method for adding a freeze crack prevention function to a fluid device, comprising the steps of: A fluid device including a casing having a flow path therein for allowing a fluid to flow, and a plug attached to the casing so as to seal the flow path, the device further including: a drill portion having a tip inlet at its tip for allowing the fluid to flow into the device; a discharge hole for discharging the fluid to the outside; an opening formed from the tip inlet to the discharge hole; and a valve disposed inside the opening for blocking the opening and stopping the fluid. The drill portion of the cock has The plug is disposed so that the tip inlet of the cock reaches the flow path inside the casing. A hole is formed in the The plug By attaching it to the wall, it prevents freezing and cracking. to the fluid device. Append vinegar This is the method. Other means will be described later. Effect of the Invention

[0009] According to the present invention, the reference pressure for starting drainage can be adjusted without disassembling the device. [Brief description of the drawings]

[0010] [Figure 1A] 1 is a front view of a centrifugal pump as an example of a fluid device according to a first embodiment. [Figure 1B] 1 is a side cross-sectional view of a centrifugal pump as an example of a fluid device according to a first embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a cock used in the first embodiment. [Diagram 3] FIG. 4 is an enlarged cross-sectional view of a modified example of the cock used in the first embodiment. [Figure 4A] FIG. 11 is a front view of a centrifugal pump as an example of a fluid device according to a second embodiment. [Figure 4B] 11 is a side cross-sectional view of a centrifugal pump as an example of a fluid device according to a second embodiment. FIG. [Diagram 5] FIG. 11 is an enlarged cross-sectional view of a cock used in embodiment 2. [Figure 6A] FIG. 11 is a front view of a centrifugal pump as an example of a fluid device according to a third embodiment. [Figure 6B] 11 is a side cross-sectional view of a centrifugal pump as an example of a fluid device according to a third embodiment. FIG. [Figure 7] FIG. 11 is a front view of a centrifugal pump as an example of a fluid device according to a fourth embodiment. [Figure 8A] FIG. 11 is an enlarged cross-sectional view of a cock used in embodiment 4. [Figure 8B] FIG. 4 is an explanatory diagram of how a cock is attached to a plug provided in a centrifugal pump. [Figure 9A] This is a schematic diagram (1) of a faucet having a three-layer main outer shell. [Figure 9B] This is a schematic diagram (2) of a faucet having a three-layer main outer shell. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that each figure merely shows a schematic view to the extent that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated examples. In each figure, common components or similar components are given the same reference numerals, and duplicated explanations thereof will be omitted. Note that in this embodiment, a single-suction single-stage volute pump, which is a centrifugal pump, will be described as an example of fluid equipment. However, the present invention is not limited to centrifugal pumps and can be applied to fluid equipment in general.

[0012] [Embodiment 1] <Configuration of centrifugal pump (fluid equipment)> The configuration of the fluidic device according to the first embodiment will be described below with reference to Fig. 1A and Fig. 1B. Fig. 1A and Fig. 1B are respectively a front view and a side cross-sectional view of a centrifugal pump 301 as an example of the fluidic device according to the first embodiment. Fig. 1B shows a layout of a cut surface, i.e., a cross section, obtained by cutting the centrifugal pump 301 shown in Fig. 1A along line Y1-Y1, as viewed from the side direction (arrow direction). In this embodiment, the description will be made on the assumption that the fluidic device is configured as a single-suction single-stage volute pump, which is the centrifugal pump 301.

[0013] 1A and 1B, a centrifugal pump 301 includes a volute casing 302 and a cock 101 that seals the flow of a fluid (water). The volute casing 302 has a suction port 313 through which the fluid is sucked, a discharge port 314 through which the fluid is discharged, and through holes such as a drain hole 310 and gauge holes 311 and 312. The drain hole 310 is a hole through which the fluid is discharged. The gauge holes 311 and 312 are holes for measuring pressure. The drain hole 310 and the gauge holes 311 and 312 are sealed with plugs.

[0014] 1B, the centrifugal pump 301 includes a rotating shaft 303 extending around an axis O disposed so as to penetrate the spiral casing 302 inside the spiral casing 302, and an impeller 304 fixed to the rotating shaft 303 so as to be integrally rotatable. The centrifugal pump 301 also includes a suction passage 305, a bearing 306 supporting the rotating shaft 303, a shaft seal 307 isolating the water passage from the atmosphere, a casing cover 308 supporting the shaft seal 307, and a motor (not shown) for rotating the impeller 304.

[0015] Inside the volute casing 302, there are provided passages for flowing a fluid, such as an intake passage 305 and a volute passage 309. The passages are composed of a space formed by the volute casing 302, a casing cover 308, and a shaft seal portion 307, and a space in which the impeller 304 is accommodated. A fluid such as water flows from the intake passage 305 into the impeller 304, is pressurized by centrifugal force due to the rotation of the impeller 304, and is discharged from an outlet of the impeller 304. The volute casing 302 has a volute passage 309 with a substantially circular cross section disposed on the outer periphery of the space in which the impeller 304 is accommodated, and efficiently guides the fluid discharged from the outlet of the impeller 304 to a discharge port portion 314. The shape of the volute passage 309 may be a substantially elliptical shape, a substantially trapezoidal shape, a substantially inverted triangle shape, or the like. The casing cover 308 and the shaft seal 307 prevent the fluid pressurized by the impeller 304 from leaking to the outside.

[0016] <Cock configuration> In the first embodiment, a frost crack prevention function is added to the centrifugal pump 301 by attaching a cock 101 to an arbitrary location of the centrifugal pump 301 (drain hole 310 in the example shown in Figs. 1A and 1B). The configuration of the cock 101 will be described below with reference to Fig. 2. Fig. 2 is an enlarged cross-sectional view of the cock 101.

[0017] As shown in FIG. 2, the faucet 101 has a screw 102, an inner plate 103, a spring 104, a valve 106, an outer lid 108, a main outer casing 109, a drain hole 110, a pump mounting threaded portion 111, and an inlet flow passage 112.

[0018] The screw 102 determines the force with which the valve 106 closes the flow path, i.e., the reference pressure at which discharge begins, by adjusting the position of the inner plate 103 and adjusting the degree of expansion and contraction of the spring 104. The screw 102 thus functions as an adjustment unit that adjusts the tension of the spring 104. The inner plate 103 is a disk-shaped member disposed so as to face the valve 106 via a spring 104 . The spring 104 is a resilient member that biases the valve 106 towards the inlet flow passage 112 .

[0019] The valve 106 is a member that blocks the inlet flow passage 112 (opening) and blocks the fluid. The valve 106 is configured by fitting a rubber packing 107 into a groove provided on the outer circumferential surface of a cylindrical valve main body 105. The valve 106 moves toward the inner plate 103 in response to an increase in pressure (water pressure) caused by freezing of the fluid entering the faucet 101 from the inlet flow passage 112. The outer cover 108 is a member attached to the outside of the main housing 109 . The main shell 109 is a cylindrical member that houses the inner plate 103, the spring 104, and the valve 106.

[0020] The drain hole 110 is a hole for discharging the fluid to the outside. The drain hole 110 is provided on the side surface of the main outer shell 109. The drain hole 110 functions as a drainage flow path when the valve 106 moves toward the inner plate 103. The pump mounting screw portion 111 is a screw portion for mounting the cock 101 to the body of the centrifugal pump 301 . The inlet passage 112 is an opening through which fluid enters the cock 101 from the centrifugal pump 301 .

[0021] The cock 101 is manufactured by assembling each component into the main outer shell 109 and then fastening the outer lid 108 to the main outer shell 109. The cock 101 is attached to a through hole provided at an arbitrary location of the spiral casing 302. Examples of the through hole include a drain hole 310 provided at the bottom of the spiral casing 302, a gauge hole 311 on the suction flange side of the spiral casing 302, and a gauge hole 312 on the discharge flange side of the spiral casing 302. The cock 101 is attached to the centrifugal pump 301 by fastening a pump mounting screw portion 111 into these through holes (the drain hole 310 in this embodiment).

[0022] In the cock 101, the valve 106 moves inside the cock 101 based on an increase in fluid pressure, thereby connecting the inlet flow path 112 to the drain hole 110. This enables the cock 101 to discharge the fluid that has entered the inside of the cock 101 due to an increase in fluid pressure to the outside through the drain hole 110.

[0023] The outer cover 108 can be made of metal or resin material as long as the desired strength can be ensured. The main outer shell 109 can be made of metal or resin material as long as the desired strength can be ensured, but since this is a part that is prone to freezing, it is better to make it of resin material if possible. The inner plate 103 can be made of metal or resin material as long as the desired strength can be ensured.

[0024] A heat insulating seal 113 (heat insulating member) is attached to the top surface (opposing surface to the inner plate 103) of the valve 106. The top surface (opposing surface to the inner plate 103) of the valve 106 is the surface opposite to the side in contact with the fluid. The faucet 101 can inhibit the transfer of heat to the spring 104 and the like by disposing the heat insulating seal 113 (heat insulating member) on the top surface (opposing surface to the inner plate 103) of the valve 106. This can suppress the tension of the spring 104 from changing. In addition to inhibiting the transfer of heat to the spring 104 and the like, the faucet 101 can also reduce the risk that the fluid (water) flowing in from the inlet flow passage 112 will freeze in the space consisting of the valve 106, the main outer casing 109, and the inlet flow passage 112. In this regard, if the fluid freezes in the above space, the flow passage connecting the inlet flow passage 112 and the discharge hole 110 will be blocked, so that even if the pressure rises due to the freezing of the fluid, the water will not be discharged, and the freeze crack prevention function will be lost. The cock 101 can reduce the loss of the freeze crack prevention function by providing a heat insulating seal 113 on the top surface (opposing surface to the inner plate 103) of the valve 106. The valve 106 may be configured so that the entire valve body 105 is made of a heat insulating material.

[0025] Also, the valve 106 may not use the rubber packing 107, and the valve body 105 itself may be made of an elastic body or the like. Also, since the valve body 105 is preferably heat-insulating, the valve body 105 may be made of a heat-insulating material, or a heat-insulating seal 113 that functions as a heat-insulating member may be attached to the surface facing the inner plate 103. Also, the discharge hole 110 may be located anywhere on the outer periphery of the main body side, as long as it is located at a position that is away from the inner plate 103 by more than the thickness of the valve 106 and is not in contact with the valve 106 when the valve 106 is closed. There is no specification for the shape of the discharge hole 110, such as a circle, an ellipse, a triangle, a square, etc., and the size and number of the discharge holes may be increased within a range that does not cause problems in terms of strength.

[0026] The spring 104 may be replaced by rubber or high-density sponge to determine the reference pressure. Also, to prevent the inside of the faucet from freezing and impeding drainage, the outer casing from the inlet flow path 112 to the discharge hole 110, which is the section through which the fluid passes, excluding the pump mounting screw part 111, may be covered with a heat-insulating sheet. The heat-insulating sheet may be a coating of heat-insulating paint or resin, or the faucet 101 itself may be given a heat-insulating function by creating an air layer or a layer of heat-insulating material such as urethane inside the main casing 109.

[0027] The operation of each mechanism of the cock 101 is as follows. That is, before the centrifugal pump 301 is operated, the position of the inner plate 103 is changed by the screw 102 to determine the tension applied to the spring 104 and adjust the reference pressure for drainage. After that, the centrifugal pump 301 starts operating at a given time. The cock 101 is designed so that the valve 106 does not operate and drainage does not occur under the pressure from the inlet passage 112 when the centrifugal pump 301 is operating. After that, the centrifugal pump 301 stops operating at a given time. When the fluid inside the volute casing 302 freezes while the centrifugal pump 301 is stopped operating, the internal pressure and the pressure applied to the cock 101 gradually increase as the fluid freezes, and the same is true for the pressure applied to the valve 106 through the inlet passage 112. When the pressure from the inlet passage 112 is equal to or lower than the reference pressure adjusted by the screw 102, the valve 106 does not operate and drainage does not occur. On the other hand, when the pressure from the inlet passage 112 exceeds the reference pressure adjusted by the screw 102, the valve 106 moves to a position where the drain hole 110 and the inlet passage 112 are opened, and water is drained from the drain hole 110. This drainage reduces the pressure, and the valve 106 returns to its original position to close the inlet passage 112.

[0028] The cock 101 discharges the fluid to the outside by such a mechanism when the pressure from the inlet flow passage 112 exceeds the reference pressure. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0029] Generally, centrifugal pumps are often installed outdoors and are exposed to environments where freeze cracking is likely to occur. On the other hand, in this embodiment, by attaching the cock 101 to the centrifugal pump 301, a freeze cracking prevention function can be added with a simple configuration and at low cost. Moreover, since the cock 101 has a function of adjusting the pressure of the fluid, in this embodiment, by simply attaching the cock 101 to the centrifugal pump 301, a pressure adjustment function can also be added easily and at low cost.

[0030] The faucet 101 can be attached to any location, such as the gauge holes 311 and 312, and not limited to the drain hole 310. When the faucet 101 is attached to the drain hole 310, the drain hole 310 generally has a relatively short overall length, so the distance between the casing flow path and the faucet 101 is short, and the risk of the inlet flow path 112 freezing and causing poor drainage can be reduced. Also, when the faucet 101 is attached to the gauge holes 311 and 312, the gauge holes 311 and 312 generally have a longer overall length than the drain hole 310, so the fluid is more likely to freeze than when the faucet 101 is attached to the drain hole 310, but the gauge holes 311 and 312 have a larger hole diameter than the drain hole 310, so clogging with solid matter such as dust and sand can be prevented.

[0031] <Modification> The cock 101 can be modified, for example, into a cock 201 shown in Fig. 3. In this modified example, a case will be described in which a fluid such as a liquid or gas is used instead of the screw 102 which is the tension adjustment mechanism.

[0032] Figure 3 shows a faucet 201 with a modified tension adjustment mechanism. As shown in Figure 3, the faucet 201 of this modification prevents freezing cracks by utilizing the pressure increase during freezing. The basic drainage mechanism is the same as that of the faucet 101. The difference is that while the faucet 101 determines the position of the inner plate 103 by the screw 102, the faucet 201 does not use the screw 102 but provides an injection plug 203, in which the fluid 202 is injected through the injection plug 203, and the position of the inner plate 103 is determined by the amount of fluid injected. By adjusting the pressure of the injected fluid 202 to the pressure during pump operation, the reference pressure can be reliably adjusted. Another advantage is that there is no need to consider physical damage to the screw.

[0033] 2, the fluid 202 injected into the injection plug 203 adjusts the position of the inner plate 103 and adjusts the degree of expansion and contraction of the spring 104, thereby determining the force with which the valve 106 closes the flow path, i.e., the reference pressure at which discharge begins. The fluid 202 injected into such an injection plug 203 functions as an adjustment part that adjusts the tension of the spring 104.

[0034] <Main features of centrifugal pumps (fluid equipment)> (1) As shown in FIG. 1A, FIG. 1B, and FIG. 2, a centrifugal pump 301 (fluid device) according to this embodiment includes a volute casing 302 and a cock 101. The volute casing 302 has flow paths (suction flow path 305, volute flow path 309, etc.) for flowing a fluid, and through holes (drain hole 310, gauge holes 311, 312, etc.). The flow paths (suction flow path 305, volute flow path 309, etc.) are configured to suck in a fluid from a suction port portion 313 and discharge the fluid from a discharge port portion 314. The cock 101 is connected to a through hole (drain hole 310 in this embodiment) and is configured so that the fluid flows in through the through hole. The cock 101 has an inlet flow path 112 (opening), a valve 106 that blocks the inlet flow path 112 and blocks the fluid, and a discharge hole 110 that discharges the fluid to the outside. The cock 101 is configured so that an inlet flow path 112 and a discharge hole 110 communicate with each other by moving a valve 106 based on an increase in the pressure of the fluid.

[0035] The centrifugal pump 301 according to this embodiment discharges the fluid to the outside when the pressure from the inlet flow passage 112 exceeds the reference pressure. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0036] (2) As shown in FIGS. 1A and 1B, in a centrifugal pump 301 according to this embodiment, the through hole to which the cock 101 is connected may be a drain hole 310.

[0037] The centrifugal pump 301 according to this embodiment discharges fluid to the outside when the pressure from the inlet flow passage 112 at the cock 101 connected to the drain hole 310 exceeds the reference pressure. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0038] (3) In the centrifugal pump 301 of this embodiment, a flange is formed at the suction port 313 through which the fluid is sucked or the discharge port 314 through which the fluid is discharged, and the through hole to which the cock 101 is connected may be a gauge hole 311, 312 on the flange side.

[0039] The centrifugal pump 301 according to this embodiment discharges the fluid to the outside when the pressure from the inlet flow passage 112 exceeds the reference pressure at the cock 101 connected to the gauge holes 311, 312. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0040] (4) As shown in Fig. 2, in the centrifugal pump 301 according to this embodiment, the valve 106 may be configured such that a heat insulating seal 113 (heat insulating member) is disposed on the surface opposite to the side in contact with the fluid. The surface opposite to the side in contact with the fluid is the top surface of the valve 106 (the surface facing the inner plate 103).

[0041] The centrifugal pump 301 according to this embodiment can inhibit the transfer of heat to the spring 104 and the like by providing a heat insulating seal 113 on the top surface of the valve 106 (the surface facing the inner plate 103). This can suppress the tension of the spring 104 from changing. In addition to inhibiting the transfer of heat to the spring 104 and the like, the centrifugal pump 301 according to this embodiment can reduce the risk of the fluid (water) flowing in from the inlet flow passage 112 freezing in the space consisting of the valve 106, the main outer shell 109, and the inlet flow passage 112. In this regard, if the fluid freezes in the above space, the flow passage connecting the inlet flow passage 112 and the discharge hole 110 is blocked, so that even if the pressure rises due to the freezing of the fluid, the water is not discharged and the freeze crack prevention function is lost. The centrifugal pump 301 according to this embodiment can reduce the loss of the freeze crack prevention function by providing a heat insulating seal 113 on the top surface of the valve 106 (the surface facing the inner plate 103).

[0042] (5) In the centrifugal pump 301 according to this embodiment, instead of providing an insulating seal 113 on the top surface of the valve 106 (the surface facing the inner plate 103), the entire valve body 105 (FIG. 2) may be made of an insulating material.

[0043] The centrifugal pump 301 according to this embodiment can inhibit the transfer of heat to the spring 104 (FIG. 2) etc. This can suppress the tension of the spring 104 from changing.

[0044] (6) As shown in FIG. 2, in the centrifugal pump 301 according to this embodiment, the cock 101 may further include an elastic portion (spring 104) connected to the valve 106 and an adjustment portion (screw 102) for adjusting the tension of the elastic portion.

[0045] The centrifugal pump 301 according to this embodiment can adjust the tension of the elastic part (spring 104). When the pressure from the inlet flow path 112 exceeds the reference pressure (the adjusted value of the tension of the elastic part (spring 104)), the centrifugal pump 301 according to this embodiment discharges the fluid to the outside. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0046] (7) In the centrifugal pump 301 according to this embodiment, the tension of the elastic portion (spring 104) is preferably adjusted to a value smaller than the pressure when the fluid freezes.

[0047] In the centrifugal pump 301 of this embodiment, the tension of the elastic part (spring 104) is set to a value smaller than the pressure when the fluid freezes, so that when the pressure from the inlet flow path 112 exceeds the reference pressure (the adjusted value of the tension of the elastic part (spring 104)), the fluid can be reliably discharged to the outside.

[0048] (8) As shown in FIG. 2, in the centrifugal pump 301 according to this embodiment, the elastic portion is a spring 104, the adjustment portion is a screw 102, and the configuration may be such that, depending on how tightly the screw 102 is tightened, an inner plate 103 located above the spring 104 is moved to control the tension of the spring 104, thereby adjusting the force applied to the valve 106.

[0049] The centrifugal pump 301 according to this embodiment adjusts the fluid pressure by adjusting the degree to which the screw 102 is tightened, thereby controlling the tension of the elastic part (spring 104) and adjusting the force applied to the valve 106, and thereby can discharge the fluid to the outside when the pressure from the inlet flow path 112 exceeds the reference pressure (the adjusted value of the tension of the elastic part (spring 104)).

[0050] (9) As shown in FIG. 3, in the centrifugal pump 301 according to this embodiment, the elastic portion is the spring 104, and the adjustment portion is the fluid injected into the injection plug 203. By adjusting the pressure of the fluid according to the degree of injection of the fluid, the inner plate 103 located above the spring 104 is moved, the tension of the spring 104 is controlled, and the force applied to the valve 106 is adjusted.

[0051] The centrifugal pump 301 according to this embodiment adjusts the fluid pressure according to the degree of fluid injection, thereby controlling the tension of the elastic part (spring 104) and adjusting the force applied to the valve 106, so that when the pressure from the inlet flow path 112 exceeds the reference pressure (the adjusted value of the tension of the elastic part (spring 104)), the fluid can be discharged to the outside.

[0052] As described above, according to the centrifugal pump 301 (fluid device) of the first embodiment, the reference pressure for starting drainage can be adjusted without disassembling the device.

[0053] [Embodiment 2] Hereinafter, the configuration of a centrifugal pump 301A according to the second embodiment will be described with reference to Fig. 4A and Fig. 4B. Fig. 4A and Fig. 4B are a front view and a side cross-sectional view, respectively, of the centrifugal pump 301A as an example of a fluidic device according to the second embodiment. Fig. 4B shows a layout of a cut surface, i.e., a cross section, obtained by cutting the centrifugal pump 301A shown in Fig. 4A along the line Y1-Y1, as viewed from the side direction (arrow direction).

[0054] As shown in Figs. 4A and 4B, the centrifugal pump 301A according to the second embodiment differs from the centrifugal pump 301 according to the first embodiment (see Figs. 1A and 1B) in that it includes a volute casing 402 instead of the volute casing 302. The volute casing 402 includes a cock 401 (see Fig. 5) integrated with the casing. Fig. 5 is an enlarged cross-sectional view of the cock 401. The main outer shell 109 of the cock 401 is integrated with the volute casing 402 of the centrifugal pump 301A. The cock 401 is formed by inserting the valve 106, the spring 104, and the inner plate 103 into the main outer shell 109, and then assembling the outer cover 108 and attaching the screw 102. The diameter and overall length of the inlet flow passage 112 of the cock 401 are preferably determined so as to maximize the reliability of the drainage mechanism operation.

[0055] The operation of each mechanism of the cock 401 is the same as the operation of each mechanism of the cock 101 (see FIG. 2) of the first embodiment, as follows. That is, before the operation of the centrifugal pump 301A, the position of the inner plate 103 is changed by the screw 102 to determine the tension applied to the spring 104, and the reference pressure for drainage is adjusted. After that, the centrifugal pump 301A starts operation at any point in time. The cock 401 is configured so that the valve 106 does not operate and drainage is not performed by the pressure from the inlet passage 112 when the centrifugal pump 301A is operating. After that, the centrifugal pump 301A stops operation at any point in time. When the fluid inside the volute casing 302 freezes when the centrifugal pump 301A stops operating, the internal pressure and the pressure applied to the cock 401 gradually increase as the fluid freezes, and the pressure applied to the valve 106 through the inlet passage 112 also increases. When the pressure from the inlet passage 112 is equal to or lower than the reference pressure adjusted by the screw 102, the valve 106 does not operate and drainage is not performed. On the other hand, when the pressure from the inlet passage 112 exceeds the reference pressure adjusted by the screw 102, the valve 106 moves to a position where the drain hole 110 and the inlet passage 112 are opened, and water is drained from the drain hole 110. This drainage reduces the pressure, and the valve 106 returns to its original position to close the inlet passage 112.

[0056] The cock 401 discharges the fluid to the outside by such a mechanism when the pressure from the inlet flow passage 112 exceeds the reference pressure. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0057] In the example shown in FIG. 4A and FIG. 4B, the centrifugal pump 301A has a protruding portion on a part of the volute casing 402, and the cock 401 is integrally provided on the protruding portion. The centrifugal pump 301A may have the cock 401 provided at any location, not limited to the protruding portion. For example, as shown in FIG. 4B, a flange is formed at the suction port portion 313 and the discharge port portion 314 of the volute casing 402 of the centrifugal pump 301A, and gauge holes 311 and 312 are formed inside the flange as through holes. The centrifugal pump 301A may have the cock 401 integral with the gauge holes 311 and 312. The centrifugal pump 301A may have the cock 401 integral with the drain hole 310.

[0058] The position and shape of the valve 106 and drain hole 110 of the cock 401 may be similar to those of the cock 101 of the first embodiment (see FIG. 2). The cock 401 may also be provided with a heat insulating seal 113 shown in FIG. 2 on the opposing surface of the valve body 105. When the cock 401 is attached to the drain hole 310, it can reduce the risk of the inlet flow path 112 freezing and causing poor drainage, similar to the cock 101 of the first embodiment (see FIG. 2). When the cock 401 is attached to the gauge holes 311, 312, it can reduce the risk of clogging with solid matter such as dust and sand, similar to the cock 101 of the first embodiment (see FIG. 2).

[0059] In the centrifugal pump 301A according to this embodiment, when the pressure from the inlet flow passage 112 exceeds the reference pressure, the cock 401 integrated with the volute casing 302 discharges the fluid to the outside. This suppresses the pressure applied to the volute casing 302, and prevents the volute casing 302 from cracking due to freezing.

[0060] [Embodiment 3] The configuration of a centrifugal pump 501 according to the third embodiment will be described below with reference to Fig. 6A and Fig. 6B. Fig. 6A and Fig. 6B are a front view and a side cross-sectional view, respectively, of the centrifugal pump 501 as an example of a fluidic device according to the third embodiment. Fig. 6B shows a layout of a cut surface, i.e., a cross section, obtained by cutting the centrifugal pump 501 shown in Fig. 6A along the line Y1-Y1, as viewed from the side direction (arrow direction).

[0061] 6A and 6B, a centrifugal pump 501 according to the third embodiment has a heat insulating sheet 502 attached to an arbitrary location of a volute casing 302 as a heat insulating member. However, the centrifugal pump 501 may be coated with heat insulating paint or resin instead of the heat insulating sheet 502. Also, the centrifugal pump 501 may have a heat insulating function in the volute casing 302 itself by providing an air layer or a layer of heat insulating material such as urethane in the outer wall of the volute flow passage 309 (see FIG. 6B).

[0062] As shown in FIG. 6A and FIG. 6B, the centrifugal pump 501 according to the third embodiment has a heat insulating sheet 502 attached to the outer periphery of the spiral casing 302 located around the cock 101, as compared with the centrifugal pump 301 according to the first embodiment (see FIG. 1A and FIG. 1B). Such a centrifugal pump 501 can delay the freezing of the fluid near the inlet passage 112 inside the cock 101 compared to the fluid in other parts. This makes it possible for the centrifugal pump 501 to avoid a situation in which the inlet passage 112 is clogged with ice, pressure is not transmitted to the valve 106, and drainage is insufficient. For this reason, it is preferable to attach the heat insulating sheet 502 only around the attachment position of the cock 101, rather than the entirety of the spiral casing 302. In order to ensure that the drainage mechanism functions perfectly, it is preferable to provide a partial heat insulating function only around the attachment position of the cock 101, as in the centrifugal pump 501 according to the third embodiment.

[0063] The centrifugal pump 501 of this embodiment has a partial insulation function only around the mounting position of the faucet 101, thereby reducing the risk of the inlet flow path 112 of the faucet 101 becoming clogged with ice, preventing pressure from being transmitted to the valve 106 and causing insufficient drainage.

[0064] [Embodiment 4] Hereinafter, the configuration of a centrifugal pump 701 according to the fourth embodiment will be described with reference to Fig. 7, and the configuration of a cock 601 attached to the centrifugal pump 701 will be described with reference to Figs. 8A and 8B. Fig. 7 is a front view of the centrifugal pump 701 as an example of a fluid device according to the fourth embodiment. Fig. 8A is an enlarged cross-sectional view of the cock 601. Fig. 8B is an explanatory diagram of attachment of the cock 601 to a plug 801 provided in the centrifugal pump 701. In this embodiment, a mechanism for preventing water leakage from the spiral casing 302 when attaching the cock 101 to the drain hole 310 and the gauge holes 311, 312 of the existing centrifugal pump 701 will be described.

[0065] 7 shows a front view of a typical existing centrifugal pump 701 with a plug 801 attached to drain hole 310 and gauge holes 311 and 312. As shown in FIG. 8B, plug 801 has a rectangular parallelepiped action part 802 and a thread part 803. Plug 801 is attached to drain hole 310 and gauge holes 311 and 312 by pressing the tip of thread part 803 against drain hole 310 and gauge holes 311 and 312 so that the threaded holes of the drain hole 310 and gauge holes 311 and 312 mesh with each other, and then fitting a wrench into action part 802 and rotating clockwise to tighten thread part 803. Thus, plug 801 closes drain hole 310 and gauge holes 311 and 312.

[0066] As shown in Fig. 8A, the cock 601 differs from the cock 101 of the first embodiment (see Fig. 2) in that a drill portion 602 is provided at the tip of the pump mounting screw portion 111, and a tip inlet 603 is provided in the drill portion 602. The tip inlet 603 is an opening that functions as a partial fluid inlet.

[0067] The drill part 602 of the cock 601 is made of a material harder than the plug 801. As shown in Fig. 8B, the cock 601 is attached to the plug 801 by pressing the tip of the drill part 602 of the cock 601 vertically against the center of the upper surface of the action part 802 of the plug 801 and rotating the cock 601 clockwise, thereby scraping off the plug 801.

[0068] In the case where the plug 801 is simply removed from the drain hole 310 and the gauge holes 311 and 312 and the cock 101 is attached to the drain hole 310 and the gauge holes 311 and 312 as in the other embodiments, the drain hole 310 and the gauge holes 311 and 312 are opened from the time when the plug 801 is removed until the cock 101 is attached. Therefore, in the other embodiments, water leakage occurs from the spiral casing 302. On the other hand, in the case where the cock 601 is attached to the plug 801 while the plug 801 is still attached from the drain hole 310 and the gauge holes 311 and 312 as in the present embodiment, the drain hole 310 and the gauge holes 311 and 312 are blocked until the cock 601 is attached. Therefore, in the present embodiment, water leakage from the spiral casing 302 can be prevented.

[0069] When the cock 601 is attached to the drain hole 310 or the gauge holes 311, 312, water flows into the interior from the tip inlet 603 through the inlet passage 112. As a result, when pressure increases due to freezing of fluid inside the spiral casing 302, the fluid pressure is transmitted to the valve 106 through the tip inlet 603 (see Figs. 8A and 8B) and the inlet passage 112 (see Fig. 8A). As a result, the cock 601 operates in the same manner as the cock 101 of the first embodiment to drain water.

[0070] 8A and 8B, the cock 601 is attached by drilling a hole on the end face of the action part 802 of the plug 801 with the drill part 602. However, the cock 601 may be attached by drilling a hole at any position of the spiral casing 302 with the drill part 602. However, when the cock 601 is attached to the end face of the action part 802 of the plug 801, the cock 601 does not protrude to the outside, compared to when the cock 601 is attached to any position of the spiral casing 302, so that the cock 601 does not get in the way.

[0071] The main housing 109 is preferably made of a synthetic resin plastic material having high strength, such as engineering plastics such as polyamide resin, polyacetal resin, polycarbonate resin, and polyethylene terephthalate resin.

[0072] Resin materials are 350 times less conductive to heat than cast iron. Therefore, by using a resin material for the main outer casing 109, it is possible to prevent the water inside the main outer casing 109 from freezing. Among the above resin materials, polyethylene terephthalate has the greatest thermal insulation properties, so polyethylene terephthalate is most preferable for the main outer casing 109.

[0073] The drill portion 602 is preferably made of a material used in general cutting tools, such as cutting tool steel (SKS material), high-speed tool steel (high-speed steel: SKH material), cemented carbide, ceramics, etc.

[0074] Since the object to be cut is made of metal, among these, cemented carbide having a certain level of hardness and toughness is particularly preferable for the drill part 602. Cemented carbide has a good balance between hardness and toughness, and can suppress the occurrence of accidents such as chipping of the drill part 602 when attaching the cock 601. It should be noted that cutting tool steel or high-speed tool steel with low hardness may not be able to cut in the first place. Also, ceramics that are extremely hard but lack toughness may cause accidents such as chipping of the blade during cutting.

[0075] The centrifugal pump 701 according to this embodiment can suppress the pressure applied to the volute casing 302 and prevent the volute casing 302 from cracking due to freezing by attaching a cock 601 to an existing pump that has already been installed on-site.

[0076] The present invention is not limited to the above-described embodiment, and includes various modified examples. For example, the above-described embodiment has been described in detail to easily explain the present invention, and is not necessarily limited to the embodiment having all of the configurations described. In addition, it is possible to replace a part of the configuration of the embodiment with another configuration, and it is also possible to add another configuration to the configuration of the embodiment. In addition, it is possible to add, delete, or replace a part of each configuration with another configuration.

[0077] In the above embodiment, the fluid device is a centrifugal pump. However, the fluid device may be, for example, a vending machine for canned juice or the like.

[0078] In addition, the main outer casing 109 of the above-mentioned cock 101 (see FIG. 2), cock 201 (see FIG. 3), cock 401 (see FIG. 5), and cock 601 (see FIG. 8A) may have a structure having two or more layers. For example, the main outer casing 109 of the above-mentioned cock 101 (see FIG. 2), cock 201 (see FIG. 3), cock 401 (see FIG. 5), and cock 601 (see FIG. 8A) may be modified like the main outer casing 905 of the cock 901 shown in FIG. 9A and FIG. 9B. FIG. 9A and FIG. 9B are schematic diagrams of the cock 901 having a three-layered main outer casing 905. FIG. 9A shows the overall configuration of the cock 901. FIG. 9B shows the configuration of the three-layered main outer casing 905 in the cock 901.

[0079] As shown in FIG. 9B, the three-layered main outer shell 905 is manufactured by placing an insulating material 903 such as glass wool or expanded polystyrene inside the outer shell 904, and inserting the inner shell 902 from above so as to sandwich the insulating material 903 between the outer shell 904 and the inner shell 902. As shown in FIG. 9A, the outer shell 904 and the inner shell 902 are fixed by tightening the outer lid 108. In addition, the contact portion between the outer shell 904 and the inner shell 902 is prevented from leaking with an adhesive such as Hermetic. The inner shell 902 and the outer shell 904 may be made of a metal or a synthetic resin or plastic material with high strength. For metal, SS material or SC material, and for synthetic resin or plastic material, engineering plastics such as polyamide resin, polyacetal resin, polycarbonate resin, and polyethylene terephthalate resin are available. However, it is preferable to manufacture the main outer shell 905 with stainless steel, which is strong and resistant to rust. The strength required to maintain the shape of the three-layered main outer shell 905 is supplemented by the outer shell 904 and the inner shell 902. The three-layer main shell 905 can use insulating materials (such as glass wool or expanded polystyrene) that have high insulating performance but low strength, so it is expected to have higher insulating properties than the main shell 109 made of synthetic resin plastic. [Explanation of symbols]

[0080] 101 Cook 102 Screw (adjustment part) 103 Inner plate 104 Spring (elastic part) 105 Valve body 106 Valve 107 Rubber packing 108 Outer lid 109 Main Outer Wall 110 Discharge hole 111 Pump mounting screw 112 Inlet channel (opening) 113 Insulation seal (insulation material) 201 Cook 202 Fluid 203 Injection plug 301, 301A Centrifugal pump (fluid equipment) 302 Spiral Casing (Casing) 303 Rotational Axis 304 Impeller 305 Suction passage (passage) 306 Bearings 307 Shaft seal 308 Casing Cover 309 Spiral Channel (Channel) 310 Drain hole (through hole) 311 Gauge hole (through hole) 312 Gauge hole (through hole) 313 Intake port 314 Discharge port 401 Cook 402 Spiral Casing (Casing) 501 Centrifugal pump (fluid equipment) 502 Heat insulation sheet (heat insulation material) 601 Cook 602 Drill Section 603 Tip inlet 701 Centrifugal pump (fluid equipment) 801 Plug 802 Action part 803 Threaded part 901 Cook 902 Inner bailey 903 Breaking material 904 Outer Wall 905 Three-layer main outer shell

Claims

1. A casing having a flow path for flowing a fluid and a through hole; a cock connected to the through hole and through which the fluid flows, The cock is an opening, a valve that closes the opening and blocks the fluid, and a discharge hole that discharges the fluid to the outside, The valve is moved based on an increase in pressure of the fluid, thereby causing the opening and the discharge hole to communicate with each other. The fluid device comprises a heat insulating member disposed on a surface of the valve opposite to the surface in contact with the fluid.

2. The fluid device according to claim 1 , wherein the through hole to which the cock is connected is a drain hole.

3. A flange is formed at the suction port portion through which the fluid is sucked or the discharge port portion through which the fluid is discharged, The fluid device according to claim 1 , wherein the through hole to which the cock is connected is a gauge hole on a flange side.

4. The fluid device according to claim 1 , wherein the valve is made of a thermal insulating material.

5. The fluid device according to claim 1 , wherein the cock further comprises an elastic portion connected to the valve, and an adjustment portion that adjusts a tension of the elastic portion.

6. The fluid device according to claim 5 , wherein the tension of the elastic portion is adjusted to a value smaller than the pressure of the fluid when frozen.

7. The elastic portion is a spring, The fluid device of claim 5, wherein the adjustment portion is a screw, and the pressure of the fluid is adjusted by tightening the screw to move an inner plate located in the upper part of the spring, thereby controlling the tension of the spring and adjusting the force applied to the valve.

8. A casing having a flow path for flowing a fluid and a through hole; a cock connected to the through hole and through which the fluid flows, The cock is an opening, a valve that closes the opening and blocks the fluid, and a discharge hole that discharges the fluid to the outside, The valve is moved based on an increase in pressure of the fluid, thereby causing the opening and the discharge hole to communicate with each other. The cock further includes an elastic portion connected to the valve and an adjustment portion for adjusting the tension of the elastic portion, The elastic portion is a spring, The adjustment part is a fluid injected into an injection plug, and by adjusting the fluid pressure depending on the degree of fluid injection, it moves the inner plate located in the upper part of the spring, controls the tension of the spring, and adjusts the force applied to the valve.

9. The fluid device according to claim 1 or 8, wherein the cock is integrated with the casing.

10. The fluid device according to claim 1 or 8, wherein the casing is provided with a partial heat insulating function only around an attachment position of the cock.

11. A casing having a flow path therein for flowing a fluid; a plug attached to the casing to seal the flow passage; A cock attached to the plug, The cock has a drill portion having a tip inlet at its tip for allowing fluid to flow into the inside, a discharge hole for discharging the fluid to the outside, an opening formed from the tip inlet to the discharge hole, and a valve disposed inside the opening for closing the opening and blocking the fluid, A fluid device in which the plug has a hole formed by the drill portion of the faucet and the faucet is attached to the plug so that the tip inlet of the faucet reaches the flow path inside the casing.

12. A fluid device comprising a casing having a flow path therein for flowing a fluid, and a plug attached to the casing so as to seal the flow path, A method for adding a freeze crack prevention function to fluid equipment, comprising: using the drill portion of a faucet having a tip inlet at its tip for allowing fluid to flow into the interior, a discharge hole for discharging the fluid to the outside, an opening formed from the tip inlet to the discharge hole, and a valve positioned inside the opening to block the opening and dam the fluid, forming a hole in the plug so that the tip inlet of the faucet reaches the flow path inside the casing, and attaching the faucet to the plug, thereby adding a freeze crack prevention function to the fluid equipment.

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