JP7637653B2 - Fluid equipment and method for adding freeze crack prevention function to fluid equipment - Google Patents

Description

The present invention relates to fluid equipment and a method for adding freeze crack prevention functionality to fluid equipment.

In facilities that handle fluids, such as industrial water supply and drainage facilities, and drinking water supply facilities for buildings and apartments, pumps are essential equipment that can be said to be the core of fluid-related systems. Abnormalities or failures in these pumps should be avoided, as they can lead to the collapse of life infrastructure and the halting 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. Pumps are particularly prone to freeze cracking, as they are often placed outdoors. Countermeasures against freeze cracking in pumps include freeze prevention operation using inverter control and the use of antifreeze.

However, freeze prevention operation using inverter control consumes electricity, and weatherproofing measures are required when installing the pump outdoors, which is costly. In addition, the use of antifreeze is known to have disadvantages such as being basically applicable only to circulation pumps and environmental pollution due to antifreeze leakage. Furthermore, in relatively warm regions, fluids do not freeze very often, so using antifreeze on a daily basis increases costs. It is also difficult to predict when the fluid will freeze, making it 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 to prevent 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 in an amount equivalent to the pressure increased by freezing.

JP 2006-64224 A

However, the conventional technology described in Patent Document 1 requires disassembly of the equipment to adjust the reference pressure for starting drainage. Because the conventional technology described in Patent Document 1 requires a lot of time and effort to make adjustments, it is desirable to be able to adjust the reference pressure for starting drainage without disassembling the equipment.

The present invention has been made to solve the above-mentioned problems, and its main objective is to provide a fluid device that allows the standard pressure at which drainage begins to be adjusted without disassembling the device, and a method for adding a freeze crack prevention function to the fluid device.

In order to achieve the above-mentioned 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 blocking the opening and damming the fluid, and a drain hole for discharging the fluid to the outside, the valve moving in response to an increase in pressure of the fluid thereby connecting the opening and the drain hole, and an insulating member arranged on the surface of the valve opposite the side in contact with the fluid .
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.

The present invention also relates to a method for adding a freeze crack prevention function to fluid equipment, which is a method for adding a freeze crack prevention function to fluid equipment comprising a casing having a flow path through which a fluid flows and a plug attached to the casing so as to seal the flow path, by using the drill part of a cock 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 positioned inside the opening to block the opening and stop the fluid, forming a hole in the plug so that the tip inlet of the cock reaches the flow path inside the casing , and attaching the cock to the plug , thereby adding a freeze crack prevention function to the fluid equipment .
Other means will be described later.

According to the present invention, the reference pressure for starting drainage can be adjusted without disassembling the device.

1 is a front view of a centrifugal pump as an example of a fluid device according to a first embodiment. 1 is a side cross-sectional view of a centrifugal pump as an example of a fluid device according to a first embodiment. FIG. 2 is an enlarged cross-sectional view of a cock used in the first embodiment. FIG. 11 is an enlarged cross-sectional view of a modified example of the cock used in the first embodiment. 11 is a front view of a centrifugal pump as an example of a fluid device according to a second embodiment. FIG. 11 is a side cross-sectional view of a centrifugal pump as an example of a fluid device according to a second embodiment. FIG. FIG. 11 is an enlarged cross-sectional view of a cock used in embodiment 2. 11 is a front view of a centrifugal pump as an example of a fluid device according to a third embodiment. FIG. 11 is a side cross-sectional view of a centrifugal pump as an example of a fluid device according to a third embodiment. FIG. A front view of a centrifugal pump as an example of a fluid device according to embodiment 4. FIG. 11 is an enlarged cross-sectional view of a cock used in embodiment 4. FIG. 4 is an explanatory diagram of how a cock is attached to a plug provided in a centrifugal pump. This is a schematic diagram (1) of a faucet having a three-layer main outer shell. This is a schematic diagram (2) of a faucet having a three-layer main outer shell.

Below, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail with reference to the drawings. Note that each figure shows only 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 and similar components are given the same reference numerals, and duplicated descriptions 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 a fluid device. However, the present invention is not limited to centrifugal pumps and can be applied to fluid devices in general.

[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 Figures 1A and 1B. Figures 1A and 1B are a front view and a side cross-sectional view, respectively, of a centrifugal pump 301 as an example of the fluidic device according to the first embodiment. Figure 1B shows a layout of a cut surface, i.e., a cross section, obtained by cutting the centrifugal pump 301 shown in Figure 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.

As shown in Figures 1A and 1B, the centrifugal pump 301 includes a volute casing 302 and a cock 101 that seals the flow of 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.

As shown in FIG. 1B, the centrifugal pump 301 includes a rotating shaft 303 that extends around an axis O that is arranged to pass through the volute casing 302 inside the volute casing 302, and an impeller 304 that is fixed to the rotating shaft 303 and can rotate integrally with the rotating shaft 303. The centrifugal pump 301 also includes an intake passage 305, a bearing 306 that supports the rotating shaft 303, a shaft seal 307 that isolates the waterway from the atmosphere, a casing cover 308 that supports the shaft seal 307, and a motor (not shown) that rotates the impeller 304.

Inside the volute casing 302, there are provided flow paths for the fluid, such as the suction flow path 305 and the volute flow path 309. The flow paths are composed of a space formed by the volute casing 302, the casing cover 308, and the shaft seal portion 307, and the accommodation space of the impeller 304. A fluid such as water flows from the suction flow path 305 into the impeller 304, is pressurized by the centrifugal force caused by the rotation of the impeller 304, and is discharged from the outlet of the impeller 304. The volute casing 302 has a volute flow path 309 with a substantially circular cross section arranged on the outer periphery of the accommodation space of the impeller 304, and efficiently guides the fluid discharged from the outlet of the impeller 304 to the discharge port portion 314. The shape of the volute flow path 309 may be substantially elliptical, substantially trapezoidal, substantially inverted triangular, 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.

<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 (the 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.

As shown in FIG. 2, the cock 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 screw portion 111, and an inlet flow passage 112.

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 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 toward the inlet flow passage 112 .

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.

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 .

The faucet 101 is manufactured by assembling each component into the main outer casing 109 and then fastening the outer lid 108 to the main outer casing 109. The faucet 101 is attached to a through hole provided at any location in the spiral casing 302. Examples of the through holes 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 faucet 101 is attached to the centrifugal pump 301 by fastening the pump mounting screw portion 111 into these through holes (the drain hole 310 in this embodiment).

When the valve 106 inside the faucet 101 moves due to an increase in fluid pressure, the inlet flow path 112 and the drain hole 110 are connected. This allows the faucet 101 to discharge the fluid that has entered the inside of the faucet 101 due to an increase in fluid pressure to the outside through the drain hole 110.

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.

An insulating seal 113 (insulating member) is attached to the top surface of the valve 106 (the surface facing the inner plate 103). The top surface of the valve 106 (the surface facing the inner plate 103) is the surface opposite to the side that contacts the fluid. The faucet 101 can inhibit the transfer of heat to the spring 104, etc. by disposing an insulating seal 113 (insulating member) on the top surface of the valve 106 (the surface facing the inner plate 103). This can suppress changes in the tension of the spring 104. In addition to inhibiting the transfer of heat to the spring 104, the faucet 101 can also reduce the risk of the fluid (water) flowing in from the inlet flow path 112 freezing in the space consisting of the valve 106, the main outer shell 109, and the inlet flow path 112. In this regard, if the fluid freezes in the space, the flow path connecting the inlet flow path 112 and the discharge hole 110 will be blocked, and 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 faucet 101 can reduce the loss of the freeze crack prevention function by providing an insulating seal 113 on the top surface of the valve 106 (the surface facing the inner plate 103). The valve 106 may be configured so that the entire valve body 105 is made of insulating material.

The valve 106 may not use rubber packing 107, and the valve body 105 itself may be made of an elastic material. Since the valve body 105 is preferably insulated, the valve body 105 may be made of an insulating material, or an insulating seal 113 that functions as an insulating member may be attached to the surface facing the inner plate 103. The discharge hole 110 may be located anywhere on the outer periphery of the main body, as long as it is located at a position that is more than the thickness of the valve 106 away from the inner plate 103 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 circular, elliptical, triangular, or rectangular, and the size and number may be increased as long as there is no problem with strength.

The spring 104 may be made of rubber or high-density sponge instead 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 heat insulation by creating an air layer or a layer of heat-insulating material such as urethane inside the main casing 109.

The operation of each mechanism of the cock 101 is as follows. That is, before the operation of the centrifugal pump 301, the position of the inner plate 103 is changed by the screw 102 to determine the tension on the spring 104 and adjust the reference pressure for drainage. After this, the centrifugal pump 301 starts operation at any time. The cock 101 is designed so that the valve 106 does not operate and drainage is not performed at the pressure from the inlet flow path 112 when the centrifugal pump 301 is operating. After this, the centrifugal pump 301 stops operation at any time. When the fluid inside the volute casing 302 freezes when the centrifugal pump 301 stops operating, the internal pressure and the pressure on the cock 101 gradually increase as the fluid freezes, and the same is true for the pressure on the valve 106 through the inlet flow path 112. If the pressure from the inlet flow path 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 flow path 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 flow path 112 are open, 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 flow path 112.

When the pressure from the inlet flow passage 112 exceeds the reference pressure, the faucet 101 uses this mechanism to discharge the fluid to the outside. This suppresses the pressure applied to the spiral casing 302 and prevents the spiral casing 302 from cracking due to freezing.

Centrifugal pumps are generally placed outdoors and are therefore exposed to environments where freeze cracking is likely to occur. On the other hand, this embodiment can add a freeze crack prevention function at low cost with a simple configuration by attaching the cock 101 to the centrifugal pump 301. Furthermore, since the cock 101 has a function for regulating the pressure of the fluid, this embodiment can also add a pressure adjustment function easily and at low cost by simply attaching the cock 101 to the centrifugal pump 301.

The cock 101 can be attached to any location, such as the gauge holes 311 and 312, not limited to the drain hole 310. When the cock 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 cock 101 is short, reducing the risk of the inlet flow path 112 freezing and causing poor drainage. Also, when the cock 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 cock 101 is attached to the drain hole 310. However, the gauge holes 311 and 312 have a larger hole diameter than the drain hole 310, so clogging with solids such as dust and sand is less likely to occur.

<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.

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 away with the screw 102 and provides an injection plug 203, which injects fluid 202 and determines the position of the inner plate 103 based on the amount 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.

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, similar to the screw 102 shown in Figure 2, 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 unit that adjusts the tension of the spring 104.

<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 such 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.

The centrifugal pump 301 according to this embodiment discharges 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.

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

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, preventing the volute casing 302 from cracking due to freezing.

(3) In the centrifugal pump 301 according to this embodiment, a flange is formed on 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 the gauge hole 311, 312 on the flange side.

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 gauge holes 311, 312 exceeds the reference pressure. This suppresses the pressure applied to the volute casing 302, preventing the volute casing 302 from cracking due to freezing.

(4) As shown in FIG. 2, in the centrifugal pump 301 according to this embodiment, the valve 106 may be configured such that an insulating seal 113 (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).

The centrifugal pump 301 according to this embodiment can inhibit the transfer of heat to the spring 104, etc., by arranging the 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, the centrifugal pump 301 according to this embodiment can reduce the risk of the fluid (water) flowing in from the inlet flow path 112 freezing in the space consisting of the valve 106, the main outer shell 109, and the inlet flow path 112. In this regard, if the fluid freezes in the above space, the flow path connecting the inlet flow path 112 and the discharge hole 110 is blocked, so that even if the pressure increases due to the freezing of the fluid, the drainage is not performed, 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 arranging the heat insulating seal 113 on the top surface of the valve 106 (the surface facing the inner plate 103).

(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 (Figure 2) may be made of insulating material.

The centrifugal pump 301 according to this embodiment can inhibit the transfer of heat to the spring 104 (FIG. 2) and other components. This can prevent the tension of the spring 104 from changing.

(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.

The centrifugal pump 301 according to this embodiment can adjust the tension of the elastic part (spring 104). The centrifugal pump 301 according to this embodiment discharges 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)). This suppresses the pressure applied to the spiral casing 302, and prevents the spiral casing 302 from cracking due to freezing.

(7) In the centrifugal pump 301 according to this embodiment, the tension of the elastic part (spring 104) may be adjusted to a value smaller than the pressure when the fluid freezes.

The centrifugal pump 301 according to this embodiment has the tension of the elastic part (spring 104) set to a value smaller than the pressure at which 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.

(8) As shown in FIG. 2, in the centrifugal pump 301 according to this embodiment, the elastic part is a spring 104, the adjustment part is a screw 102, and the inner plate 103 located above the spring 104 is moved depending on how tightly the screw 102 is tightened, thereby controlling the tension of the spring 104 and adjusting the force applied to the valve 106.

The centrifugal pump 301 according to this embodiment adjusts the pressure of the fluid 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 is therefore capable of discharging 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)).

(9) As shown in FIG. 3, in the centrifugal pump 301 according to this embodiment, the elastic part is the spring 104, and the adjustment part 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.

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, and is therefore capable of discharging 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)).

As described above, the centrifugal pump 301 (fluid device) according to this embodiment 1 allows the reference pressure for starting drainage to be adjusted without disassembling the device.

[Embodiment 2]
The configuration of a centrifugal pump 301A according to the second embodiment will be described below with reference to Figures 4A and 4B. Figures 4A and 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. Figure 4B shows a layout of a cut surface, i.e., a cross section, obtained by cutting the centrifugal pump 301A shown in Figure 4A along line Y1-Y1, as viewed from the side direction (arrow direction).

As shown in Figures 4A and 4B, the centrifugal pump 301A according to the second embodiment differs from the centrifugal pump 301 according to the first embodiment (see Figures 1A and 1B) in that it has a spiral casing 402 instead of the spiral casing 302. The spiral casing 402 has a cock 401 (see Figure 5) integrated with the casing. Figure 5 is an enlarged cross-sectional view of the cock 401. The main outer shell 109 of the cock 401 is integrated with the spiral 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, 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.

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 on the spring 104 and adjust the reference pressure for drainage. After this, the centrifugal pump 301A starts operating at any time. The cock 401 is designed so that the valve 106 does not operate and drainage is not performed by the pressure from the inlet flow path 112 when the centrifugal pump 301A is operating. After this, the centrifugal pump 301A stops operating at any time. When the fluid inside the volute casing 302 freezes when the centrifugal pump 301A stops operating, the internal pressure and the pressure on the cock 401 gradually increase as the fluid freezes, and the pressure on the valve 106 through the inlet flow path 112 also increases. When the pressure from the inlet flow path 112 is equal to or lower than the reference pressure adjusted by the screw 102, the valve 106 does not operate and no drainage occurs. On the other hand, when the pressure from the inlet flow path 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 flow path 112 are open, and drainage occurs from the drain hole 110. This drainage reduces the pressure, and the valve 106 returns to its original position to block the inlet flow path 112.

The cock 401 uses this mechanism to discharge 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 spiral casing 302 and prevents the spiral casing 302 from cracking due to freezing.

In the example shown in Figures 4A and 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. Note that the centrifugal pump 301A can have the cock 401 at any location, not just the protruding portion. For example, as shown in Figure 4B, flanges are formed on 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 flanges 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 also have the cock 401 integral with the drain hole 310.

The position and shape of the valve 106 and drain hole 110 of the faucet 401 may be the same as those of the faucet 101 of embodiment 1 (see FIG. 2). The faucet 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 faucet 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 faucet 101 of embodiment 1 (see FIG. 2). When the faucet 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 faucet 101 of embodiment 1 (see FIG. 2).

The centrifugal pump 301A according to this embodiment uses a cock 401 integrated with the volute casing 302 to discharge 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.

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

As shown in Figures 6A and 6B, the centrifugal pump 501 according to the third embodiment has a heat insulating sheet 502 attached to any location of the 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 the volute casing 302 itself provided with heat insulating properties 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 Figure 6B).

As shown in Figures 6A and 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, compared to the centrifugal pump 301 according to the first embodiment (see Figures 1A and 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 allows the centrifugal pump 501 to avoid the inlet passage 112 being clogged with ice, pressure not being transmitted to the valve 106, and insufficient drainage. Therefore, it is preferable to attach the heat insulating sheet 502 only around the mounting position of the cock 101, rather than the entire 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 mounting position of the cock 101, as in the centrifugal pump 501 according to the third embodiment.

The centrifugal pump 501 according to this embodiment has a partial insulation function only around the mounting position of the faucet 101, which reduces the possibility that the inlet flow path 112 of the faucet 101 will become clogged with ice, preventing pressure from being transmitted to the valve 106 and causing insufficient drainage.

[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 and 312 of the existing centrifugal pump 701 will be described.

Figure 7 shows the front configuration of a typical existing centrifugal pump 701 with a plug 801 attached to the drain hole 310 and gauge holes 311 and 312. As shown in Figure 8B, the plug 801 has a rectangular parallelepiped action part 802 and a thread part 803. The plug 801 is attached to the drain hole 310 and gauge holes 311 and 312 by pressing the tip of the thread part 803 against the 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 the action part 802 and rotating it clockwise to tighten the thread part 803. In this way, the plug 801 blocks the drain hole 310 and gauge holes 311 and 312.

As shown in FIG. 8A, the cock 601 differs from the cock 101 of embodiment 1 (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.

The drill portion 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 portion 602 of the cock 601 vertically against the center of the upper surface of the action portion 802 of the plug 801 and rotating the cock 601 clockwise, while scraping off the plug 801.

As in other embodiments, when 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, the drain hole 310 and the gauge holes 311 and 312 are opened between the removal of the plug 801 and the attachment of the cock 101. Therefore, in other embodiments, water leakage occurs from the spiral casing 302. On the other hand, as in this embodiment, when 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, the drain hole 310 and the gauge holes 311 and 312 are blocked until the cock 601 is attached. Therefore, in this embodiment, water leakage from the spiral casing 302 can be prevented.

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 the fluid inside the spiral casing 302, the fluid pressure is transmitted to the valve 106 through the tip inlet 603 (see Figures 8A and 8B) and the inlet passage 112 (see Figure 8A). As a result, the cock 601 operates in the same way as the cock 101 of embodiment 1 to drain water.

In the example shown in Figures 8A and 8B, the cock 601 is attached by drilling a hole on the end surface 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 location on the spiral casing 302 with the drill part 602. However, when the cock 601 is attached to the end surface 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 location on the spiral casing 302, so the cock 601 can be configured not to get in the way.

The main outer shell 109 is preferably made of a synthetic resin plastic material with high strength. Examples of synthetic resin plastic materials include engineering plastics such as polyamide resin, polyacetal resin, polycarbonate resin, and polyethylene terephthalate resin.

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 insulating properties, so it is most preferable for the main outer casing 109.

The drill portion 602 is preferably made of a material that is used in general cutting tools. Materials that are used in general cutting tools include cutting tool steel (SKS material), high-speed tool steel (HSS: SKH material), cemented carbide, ceramics, etc.

Because the object to be cut is made of metal, cemented carbide, which has 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 prevent 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, which have low hardness, may not be able to cut at all. Also, ceramics, which are extremely hard but lack toughness, may cause accidents such as the blade chipping during cutting.

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

The present invention is not limited to the above-described embodiment, but includes various modified examples. For example, the above-described embodiment has been described in detail to explain the present invention in an easy-to-understand manner, and is not necessarily limited to having all of the configurations described. In addition, it is possible to replace 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 part of each configuration with another configuration.

In the above embodiment, the fluid device is assumed to be a centrifugal pump, but the fluid device may also be, for example, a vending machine for canned juice, etc.

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

As shown in FIG. 9B, the three-layered main outer shell 905 is manufactured by placing 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 part 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 high-strength metal or synthetic resin or plastic material. For metals, SS material or SC material, and for synthetic resin or plastic materials, engineering plastics such as polyamide resin, polyacetal resin, polycarbonate resin, and polyethylene terephthalate resin are available, but it is preferable to manufacture the main outer shell 905 of the three-layered structure by stainless steel, which is also 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-layered main outer 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 outer shell 109 made of synthetic resin plastic.

101 Cock 102 Screw (adjustment part)
103 Inner plate 104 Spring (elastic part)
105 Valve body 106 Valve 107 Rubber packing 108 Outer cover 109 Main outer shell 110 Discharge hole 111 Pump mounting screw portion 112 Inlet flow path (opening)
113 Heat insulating seal (heat insulating member)
201 Cock 202 Fluid 203 Injection plug 301, 301A Centrifugal pump (fluid equipment)
302 Spiral casing (casing)
303 Rotating shaft 304 Impeller 305 Suction passage (passage)
306 Bearing 307 Shaft seal portion 308 Casing cover 309 Spiral flow path (flow path)
310 Drain hole (through hole)
311 Gauge hole (through hole)
312 Gauge hole (through hole)
313 Suction port 314 Discharge port 401 Cock 402 Spiral casing (casing)
501 Centrifugal pump (fluid equipment)
502 Heat insulating sheet (heat insulating material)
601 Cock 602 Drill portion 603 Tip inlet 701 Centrifugal pump (fluid equipment)
801 plug 802 action part 803 thread part 901 cock 902 inner shell 903 insulating material 904 outer shell 905 three-layer main outer shell

Claims (12)

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 . The fluid device according to claim 1, wherein the through hole to which the cock is connected is a drain hole. 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. The fluid device according to claim 1, wherein the valve is made of a thermal insulating material. The fluid device according to claim 1, wherein the cock further has an elastic part connected to the valve and an adjustment part for adjusting the tension of the elastic part. 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. 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 . 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, the inner plate located in the upper part of the spring is moved, thereby controlling the tension of the spring and adjusting the force applied to the valve . The fluid device according to claim 1 or 8 , wherein the cock is integrated with the casing. 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. A casing having a flow path therein for allowing a fluid to flow;
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 . 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,
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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