Antifreeze valve for high-pressure water

Abstract

To provide an antifreeze valve for high-pressure water having a flow rate adjusting function in which the flow rate increases or decreases in proportion to the valve opening, and the range of increase or decrease in relation to the valve opening is appropriate. [Solution] The high-pressure water antifreeze valve comprises a valve body having an inlet for high-pressure water, and a valve body unit that moves within the inlet to open and close the flow path formed between the inlet and the valve body. The valve body unit has a seal portion that closes the flow path by coming into close contact with the inlet and opens the flow path by moving away from the inlet. The valve body unit has a flow rate adjustment portion that is arranged in contact with the seal portion and adjusts the flow rate of high-pressure water flowing through the flow path. The seal portion and the flow rate adjustment portion are supported by the valve body. The flow rate adjustment portion is formed so that it gradually becomes deeper and wider in a direction away from the seal portion, and has a plurality of grooves arranged in the circumferential direction of the flow rate adjustment portion. The inner surface of each of the plurality of grooves has a linear shape in the direction along the central axis of the inlet, and an arc shape in the circumferential direction.

Description

[Technical Field]

[0001] The present invention relates to an antifreeze valve that discharges water from a pipe to prevent the pipe from freezing, and more particularly to an antifreeze valve for high-pressure water that is suitable for use in high-pressure water pipes. [Background technology]

[0002] In cold regions, antifreeze valves are generally installed in the water pipes of buildings to prevent the water pipes from freezing during the winter. When there is a concern about the water pipes freezing, the antifreeze valve can be operated to drain (drain) the water from the pipes, thereby preventing freezing accidents before they occur. In addition to those installed in buildings such as detached houses and apartment buildings, there are also high-pressure water antifreeze valves (hereinafter sometimes simply referred to as "antifreeze valves") that can use water with a higher water pressure than the water pressure used in these buildings (referred to as "high-pressure water" in this specification).

[0003] An example of a high-pressure water antifreeze valve is one installed in the pipes supplying water to a snowmaking machine. Snowmaking machines are supplied with high-pressure water, which is created by pressurizing water from a water source using a pump. Antifreeze valves are typically installed between the pump and the snowmaking machine. Snowmaking machines can be supplied with high-pressure water of up to 2 MPa, and the antifreeze valves used in such machines are also designed to be compatible with high-pressure water. The amount of snow made by a snowmaking machine can be adjusted by increasing the water pressure supplied to the machine to increase the amount of snow made, or by decreasing the water pressure to decrease the amount of snow made.

[0004] Water pressure can be adjusted by remotely opening and closing the valve of the antifreeze valve installed upstream of the snow machine based on monitoring information from a water pressure gauge (or water pressure sensor) installed in the pipes near the snow machine, and adjusting the flow rate supplied from the antifreeze valve to the snow machine. By operating the antifreeze valve to the fully closed position (draining water), the water supply downstream of the valve can be cut off. After using the snow machine, freezing accidents can be prevented by opening the valve to the draining position and draining the water from the antifreeze valve, the pipes downstream of the antifreeze valve, and the snow machine outside the pipes.

[0005] Conventionally, water faucets or antifreeze faucets have been proposed as disclosed in Patent Document 1, Patent Document 2, and Non-Patent Document 1. The faucet disclosed in Patent Document 1 has a flow control valve portion (7) protruding from a valve opening / closing portion (5) of a valve body, the diameter of which is slightly smaller than the diameter of the valve orifice (6). The flow control valve portion (7) has a structure in which several fluid guide grooves (8) are formed on its peripheral surface, the depth and width of which gradually decrease from the outer end of the flow control valve portion (7) toward the valve opening / closing portion (5). As can be seen from a longitudinal cross-sectional view of the center of the width direction, the inner surface of the fluid guide groove (8) has a shape that curves from near the center of the underside of the flow control valve portion (7) toward the upper side (see Figure 2(b) of Patent Document 1). When the flow control valve portion (7) of the valve body (1) is inserted into the valve orifice (6), the fluid flows out through a conduit formed by the fluid guide grooves (8) and the inner wall surface of the valve orifice (6).

[0006] Patent Document 2 discloses a water faucet for an artificial snow machine. The faucet disclosed in Patent Document 2 has a truncated cone-shaped adjusting portion (20) covered with packing (16) for adjusting the flow pressure, and a truncated cone-shaped water-stopping portion (22) connected to it for stopping water, the former being higher than the latter, and the larger and smaller bottom surfaces of the former and latter having the same diameter as each other to form an integrated valve body (12), and a valve seat (40) having a valve body insertion space (42) that matches the outer shapes of the adjusting portion (20) and the water-stopping portion (22).

[0007] Non-Patent Document 1 discloses a remotely operable antifreeze valve used to adjust the amount of snow made by an artificial snow machine. This antifreeze valve has a flow rate adjusting member, and on the outer periphery of the flow rate adjusting member, there are provided multiple grooves with acute-angled apexes and corners where the surfaces intersect, each groove having an internal surface formed by a combination of flat surfaces, as water flow paths. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Jikko No. 60-37494 [Patent Document 2] Publication number 03-32848 [Non-patent literature]

[0009] [Non-Patent Document 1] Rogers Hydrant Company "UNDERGROUND HYDRANTS" Catalog Summary of the Invention [Problem to be solved by the invention]

[0010] Multiple snow machines are often deployed over a wide area, such as at a ski resort. Therefore, it is preferable to be able to remotely control the snow production volume and drain the water from the snow machine to improve the efficiency of snow production. When adjusting the snow production volume of a snow machine by remote control, the flow rate of high-pressure water supplied to the snow machine is adjusted by remotely changing the valve opening of an antifreeze valve, in order to change the measurement value of a water pressure gauge installed in the pipe near the snow machine to a target value corresponding to the snow production volume.

[0011] However, when the water pressure gauge and the antifreeze valve are installed far apart due to piping restrictions or other factors, and the accuracy of flow rate adjustment in response to the valve opening is low—for example, when the flow rate does not increase or decrease in proportion to the valve opening, when the flow rate increases or decreases in proportion to the valve opening but by a large amount, or when the increase or decrease in flow rate changes rapidly beyond a certain valve opening—the flow rate is likely to overshoot the target value even if a command to stop the antifreeze valve valve operation is issued via remote control immediately after the water pressure gauge measurement reaches the target value. This overshoot converges after repeated opening and closing of the valve to correct the overshoot, so if the accuracy of flow rate adjustment in response to the valve opening is low, it takes a long time for the flow rate to settle to the target value. On the other hand, even if the flow rate increases or decreases in proportion to the valve opening, if the amount of increase or decrease is small, when a command is issued by remote control to stop the antifreeze valve valve operation immediately after the water pressure gauge measurement value reaches the target value, the flow rate will settle to the target value relatively quickly, but the total time required to remotely operate the antifreeze valve will be longer.

[0012] To be able to adjust to the target water pressure in a short time, an antifreeze valve with high accuracy in flow rate adjustment is required, i.e., an antifreeze valve that increases or decreases the flow rate in proportion to the valve opening and that has an appropriate range of increase or decrease in flow rate relative to the valve opening. Furthermore, if the antifreeze valve allows for high-accuracy flow rate adjustment via remote control, even higher accuracy flow rate adjustment is possible when operated manually.

[0013] In the faucet disclosed in Patent Document 1, due to the curved shape of the inner surface of the fluid guide groove (8), the flow rate does not increase or decrease in proportion to the valve opening, and the range of increase or decrease in flow rate in response to changes in the valve opening is large.In the faucet disclosed in Patent Document 2, the flow rate changes suddenly when the lower tip of the valve element (12) moves out of the valve element insertion space (42) during valve opening adjustment.Therefore, when adjusting the amount of snow made by an artificial snow machine, even if the faucet is turned off immediately after the measurement value of the water pressure gauge reaches the target value, the flow rate will overshoot the target value and it will take time to finally settle at the target value.

[0014] On the other hand, it is preferable that the flow rate adjusting member that contributes to flow rate adjustment be easy to manufacture and be easy to maintain. In the antifreeze valve described in Non-Patent Document 1, the grooves provided as water flow paths on the outer periphery of the flow rate adjusting member have acute-angled apexes, making them difficult to manufacture by cutting, and the interior is formed by a combination of flat surfaces, with corners where the surfaces intersect, creating a large resistance to the flowing water.

[0015] In view of the above, an object of the present invention is to provide an antifreeze valve for high-pressure water that has a flow rate adjustment function in which the flow rate increases or decreases in proportion to the valve opening, and the increase or decrease range is appropriate for the valve opening. Another object of the present invention is to provide an antifreeze valve for high-pressure water that is easy to manufacture as a component having a flow rate adjusting function and that can improve the water-stopping performance of the valve packing. [Means for solving the problem]

[0016] The present invention provides an antifreeze valve for high-pressure water. The antifreeze valve for high-pressure water includes a valve body having an inlet for high-pressure water therein, and a valve body unit that moves within the inlet to open and close a flow path formed between the inlet and the valve body. The valve body unit has a seal portion that closes the flow path by coming into close contact with the inlet and opens the flow path by moving away from the inlet. The valve body unit further has a flow rate adjustment portion that is arranged in contact with the seal portion, and the flow rate adjustment portion adjusts the flow rate of high-pressure water flowing through the flow path. The seal portion and the flow rate adjustment portion are supported by the valve body. The flow rate adjustment portion has a plurality of grooves. The plurality of grooves are formed so that they become gradually deeper and wider in a direction away from the seal portion, and are arranged in the circumferential direction of the flow rate adjustment portion. The inner surface of each of the plurality of grooves has a linear shape in a direction along the central axis of the inlet and an arc shape in the circumferential direction.

[0017] In one embodiment, the flow rate adjusting portion has a plurality of guides. The plurality of guides can abut against the inlet portion to maintain the position of the flow rate adjusting portion when the sealing portion is separated from the inlet portion. In one embodiment, one or more of the plurality of grooves are arranged between adjacent guides.

[0018] In one embodiment, the seal closes the flow path by adhering to the inner wall of the inlet and opens the flow path by separating from the inner wall. The seal is preferably made of an elastomer. The elastomer is preferably an ether-based urethane rubber or a styrene-butadiene rubber, which are classified as thermosetting elastomers.

[0019] In one embodiment, the valve body unit further includes a retaining portion. The retaining portion holds the seal portion in a predetermined position by sandwiching the seal portion between the retaining portion and the flow rate adjusting portion. The retaining portion is preferably made of a synthetic resin or rubber. In one embodiment, the seal portion has an outer diameter smaller than that of the retaining portion, and the portion of the retaining portion that protrudes from the seal portion is in close contact with the upper surface of the inlet portion. In one embodiment, the valve body has a flange that prevents the retaining portion from expanding outward. [Effects of the Invention]

[0020] According to the present invention, the high-pressure water antifreeze valve is provided with a flow rate adjusting section having multiple grooves shaped such that the total flow rate cross-sectional area increases or decreases in proportion to the valve opening, so the flow rate increases or decreases in proportion to the valve opening. Furthermore, the shape of the grooves in the high-pressure water antifreeze valve can be easily machined using a tool such as an end mill. [Brief explanation of the drawings]

[0021] [Figure 1] 1A and 1B are longitudinal cross-sectional views of a high-pressure water antifreeze valve according to an embodiment of the present invention, in which FIG. 1A shows a water-draining state and FIG. 1B shows a water-supplying state. [Figure 2] 1A and 1B are perspective views of a valve body unit of a high-pressure water antifreeze valve according to an embodiment of the present invention, in which FIG. 1A shows an assembled state and FIG. 1B shows an exploded state. [Figure 3] 1 shows a flow rate adjusting section used in a valve body unit of a high-pressure water antifreeze valve according to one embodiment of the present invention, where (a) is an external perspective view, (b) is a longitudinal cross-sectional view, (c) is a transverse cross-sectional view, and (d) is a schematic diagram showing the concept of the groove shape. [Figure 4]1A and 1B are longitudinal cross-sectional views of the high-pressure water inlet and valve body unit used in a conventional high-pressure water antifreeze valve, where (a) shows the water draining state, (b) shows the water supply state, and (c) shows an oblique view of the valve piece gasket. [Figure 5] FIG. 10 is a perspective view of a flow rate adjusting portion of a high-pressure water antifreeze valve according to another embodiment of the present invention. [Figure 6] This is a graph comparing the flow characteristics of the valve body unit of a high-pressure water antifreeze valve according to one embodiment of the present invention with the flow characteristics when a flow control unit of a shape disclosed in the prior art is used instead of the flow control unit of the valve body unit. [Figure 7] 7A and 7B are cross-sectional views showing the configurations of the valve body unit and flow rate adjusting section used to calculate each flow rate characteristic in the graph of FIG. 6, where (a) shows a valve body unit incorporating a flow rate adjusting section having a shape disclosed in Patent Document 1, and (b) shows a valve body unit incorporating a flow rate adjusting section having a shape disclosed in Patent Document 2. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a longitudinal cross-sectional view of a high-pressure water antifreeze valve 1 according to one embodiment of the present invention, where (a) shows the water draining state and (b) shows the water supply state. Fig. 2 is a perspective view of a valve body unit 10 of the high-pressure water antifreeze valve 1, where (a) shows the assembled state and (b) shows the disassembled state. Fig. 3 shows a flow rate adjusting section 14 used in the valve body unit 10 of the high-pressure water antifreeze valve 1, where (a) is an external perspective view, (b) is a longitudinal cross-sectional view, (c) is a cross-sectional view, and (d) is a schematic diagram showing the concept of the groove shape.

[0023] 1. Configuration of high-pressure water antifreeze valve (Overall composition) As shown in FIG. 1, a high-pressure water antifreeze valve 1 (hereinafter referred to as antifreeze valve 1) comprises a valve box 2, a riser pipe 3, an upper fitting 4, a gland 5, a spindle 6, a spindle joint 7, a center shaft 8, and a drain valve unit 20. A cylinder 2d is provided inside the valve box 2, and a valve element unit 10 is disposed inside the cylinder 2d, which moves up and down while in close contact with or abutting against the cylinder 2d. As shown in FIG. 2, the valve element unit 10 comprises a valve element 11, a stopper ring 12, a valve packing 13, a flow rate adjusting portion 14, a washer 15, a hexagonal nut 16, and an O-ring 17. As shown in FIG. 1, the drain valve unit 20 comprises a drain valve body 21, a drain plug 22, a ball (stop valve) 23, a drain valve spring 24, and an O-ring 25.

[0024] The valve box 2 has, from bottom to top, an inlet 2a connected to the upstream piping, a lower space 2b located above the inlet 2a and in which part of the flow rate regulator 14 is disposed, a cylinder 2d serving as the inlet for high-pressure water, a communication port 2c formed inside the inner wall of the cylinder 2d, and an upper space 2e above the cylinder 2d. A valve seat 2f is provided on the top surface of the cylinder 2d. The inlet 2a, lower space 2b, communication port 2c, and upper space 2e are connected to each other and share the same central axis. The valve unit 10 moves up and down inside the cylinder 2d to open and close the flow path formed between the valve unit 10 and the inner wall of the cylinder 2d, and the flow rate regulator 14 adjusts the flow rate of the high-pressure water flowing through the path.

[0025] A drain port 2g is formed in part of the side wall of the upper space 2e of the valve box 2, and a drain valve unit 20 is screwed into the drain port 2g. The drain valve unit 20 is composed of a drain valve main body 21, a drain plug 22, a ball 23, a drain valve spring 24, and an O-ring 25. One side of the drain valve main body 21 is screwed into the drain port 2g. The drain plug 22 is screwed into the other side of the drain valve main body 21. The internal space where the drain valve main body 21 and the drain plug 22 are connected contains a ball 23 which functions as a stop valve, the drain valve spring 24, and the O-ring 25. The ball 23 is constantly subjected to a force pressed in the opposite direction to the O-ring 25 by the drain valve spring 24.

[0026] The male thread 3a of the riser pipe 3 is threaded onto the top of the valve box 2 via the female thread 2h. The female thread 4b of the upper fitting 4 is threaded onto the male thread 3b at the top end of the riser pipe 3. An outlet 4a is provided on the side of the upper fitting 4, and the outlet 4a is connected to a snow machine via downstream piping. A female thread 4c is provided on the upper end of the upper fitting 4, and the male thread 5a of the gland 5 is threaded onto the female thread 4c. The shaft 6a of the spindle 6 is inserted into the axial center of the gland 5. A mating protrusion 6c is provided on the lower end of the spindle 6, and the mating protrusion 6c is connected to the mating recess 7a of the spindle coupling 7. A handle (not shown) is attached to the upper end of the spindle 6 for manual operation, or an adapter member (not shown) is used to connect to the drive unit for remote operation using a drive unit. A female thread 7b is provided at the lower end of the spindle joint 7, and a male thread 8a provided at the upper end of the intermediate shaft 8 is screwed into the female thread 7b. A male thread 8b is provided at the lower end of the intermediate shaft 8, and a female thread 11b of the valve body 11 that constitutes the valve body unit 10 is screwed into the male thread 8b.

[0027] (Valve body unit of conventional antifreeze valve) Here, the structure of the valve body unit 110 in a conventional high-pressure water antifreeze valve 101 (hereinafter referred to as antifreeze valve 101) manufactured by the present applicant will be described. Figure 4 shows a vertical cross-sectional view of the valve body unit 110 used in the conventional antifreeze valve 101, with (a) showing the water drain state, (b) showing the water supply state, and (c) showing a perspective view of the valve block packing. Note that the antifreeze valve 101 can employ the same configuration as the above-mentioned antifreeze valve 1 other than the valve body unit 110, and the same components as in Figure 1 are designated by the same reference numerals in Figure 4.

[0028] The valve element unit 110 opens and closes the flow path formed between it and the cylinder 2d by moving up and down inside the valve box 2. The valve element unit 110 is composed of a valve element 111 that adjusts the flow rate of high-pressure water flowing through the flow path, a valve piece packing 113, and a packing gland 116. As with the antifreeze valve 1 according to the present invention, a male thread 8b is provided at the lower end of the central shaft 8, and a female thread 111a is threadedly engaged with the male thread 8b at the upper end of the substantially cylindrical valve element 111 that constitutes the valve element unit 110. A substantially circular recess 111b is provided at the bottom of the valve element 111, and the valve piece packing 113 is attached to the recess 111b.

[0029] As shown in Figure 4(c), the valve piece packing 113 has a generally annular upper portion with a circular through-hole 113a in the center and four guides 113e extending downward from the generally annular upper portion. Grooves 113d that communicate with the through-holes 113a are provided between adjacent guides 113e on the side of the valve piece packing 113, from near the center to the bottom end. The width of the grooves 113d is the same from top to bottom, and all four grooves 113d are formed with the same shape. The valve piece packing 113 is fixed to the valve piece 111 by being sandwiched between the valve piece 111 and the packing gland 116. The upper portion of the through-hole 113a is blocked by the engagement of the female thread 111c of the valve piece 111 with the male thread 116a of the packing gland 116.

[0030] When the valve unit 110 is in the fully closed state (draining state) shown in Figure 4(a), the underside of the shoulder 113f of the valve piece packing 113 of the valve unit 110 is in close contact with the valve seat 2f of the valve box 2, so water flowing in from the inlet 2a of the valve box 2 is not supplied to the downstream piping or the snow machine. To transition from this state to the water supply state shown in Figure 4(b), the spindle 6 is rotated, and the valve unit 110, which is connected via the middle shaft 8, is moved upward. When the valve unit 110 moves upward, the underside of the shoulder 113f of the valve piece packing 113 separates from the valve seat 2f, and water flowing in from the inlet 2a flows through the lower space 2b, the communication port 2c, the lower part of the through-hole 113a of the valve piece packing 113, the groove 113d, the upper space 2e, the riser pipe 3, and the outlet 4a of the upper fitting 4, and is supplied to the snow machine via the downstream piping connected to the outlet 4a. The amount of snow made by the snow machine can be increased or decreased by changing the valve opening to adjust the water pressure supplied to the snow machine.

[0031] The conventional antifreeze valve 101 equipped with the valve body unit 110 may have the following problems. First, the antifreeze valve 101 was not designed with remote operation in mind. Therefore, when operated remotely, the flow rate does not increase or decrease in proportion to the valve opening, and particularly in the low flow rate range, when the valve opening is increased, the flow rate increases suddenly at a certain valve opening. This creates the problem that even if the remote operation of the antifreeze valve is stopped immediately after the water pressure gauge measurement value reaches the target value, the value will deviate from the target value.

[0032] Second, the antifreeze valve 101 uses a fluorine-based synthetic resin (for example, Teflon (a registered trademark of DuPont)) for the valve piece packing 113 of the valve body unit 110, and employs a structure in which the underside of the shoulder 113f is tightly attached to the valve seat 2f to block water. The valve piece packing 113 made of a fluorine-based synthetic resin does not have perfect water-stopping performance, and there is a risk of water leakage.

[0033] (Valve body unit of antifreeze valve according to the present invention) The antifreeze valve 1 of the present invention can solve not only the above-mentioned problems of the conventional antifreeze valve 101 but also the problems of other conventional antifreeze valves by employing a valve unit 10 having the configuration described below. As described above, the valve unit 10 has a valve 11, a stopper ring 12, a valve packing 13, a flow rate adjusting portion 14, a washer 15, a hexagonal nut 16, and an O-ring 17.

[0034] 1 and 2, the valve disc 11 has an upper portion 11a, an internal thread 11b formed on the upper portion 11a, a recess 11c formed below the upper portion 11a, a flange 11d extending downward from the outer edge of the upper portion 11a to cover the recess 11c, and a shaft portion 11e extending downward from the center of the upper portion 11a. A stopper ring (retaining portion) 12, a valve packing (sealing portion) 13, and a flow rate adjusting portion 14 are inserted and supported on the shaft portion 11e of the valve disc 11, in that order, and these are fixed to the shaft portion 11e with a washer 15 and a hexagonal nut 16 so as not to fall off. The material of the valve disc 11 is not limited as long as it has high durability and mechanical strength for use in high-pressure water, but is preferably metal, and more preferably cast bronze or stainless steel.

[0035] The stopper ring 12 has a generally annular shape, with the shaft 11e inserted through the central hole and positioned in the recess 11c, and is supported by the valve body 11. The outer surface of the stopper ring 12 abuts against the inner surface of the flange 11d of the valve body 11. The thickness of the stopper ring 12 is greater than the depth of the recess 11c, and a lower portion of the stopper ring 12 protrudes downward from the recess 11c. As described below, the protruding lower portion, more specifically, the outer edge of the lower surface 12a of the stopper ring 12, comes into close contact with the valve seat 2f on the upper surface of the cylinder 2d when the antifreeze valve 1 is in a draining state. The outer surface of the stopper ring 12 abuts against the inner surface of the flange 11d, preventing the stopper ring 12 from deforming and expanding outward, even if the lower surface 12a of the stopper ring 12 repeatedly comes into close contact with the valve seat 2f due to repeated valve opening and closing operations. The material of the stopper ring 12 is not limited as long as it has low water absorption and high mechanical strength when used in high-pressure water, and is preferably synthetic resin or rubber.

[0036] Valve packing 13 has a generally annular shape, with shaft 11e inserted through a central hole and supported by valve element 11 while abutting against underside 12a of stopper ring 12. Valve packing 13 is smaller than the outer diameter of stopper ring 12 and slightly larger than the diameter of the inner wall of cylinder 2d. Therefore, when antifreeze valve 1 is in a draining state, side surface 13a of valve packing 13 and the inner wall of cylinder 2d come into close contact, providing a water-stopping function that blocks the flow of high-pressure water through communication port 2c. The thinner the thickness of valve packing 13, the better, as long as water-stopping performance and mechanical strength are maintained when used in high-pressure water; for example, it can be approximately 3 mm. The valve packing 13 is sandwiched between the upper surface 14b of the flow rate adjustment section 14 described below and the lower surface 12a of the stopper ring 12, thereby preventing the valve packing 13 from falling off or turning over from the valve body unit 10 due to the flow of high-pressure water during water supply, i.e., keeping the valve packing 13 in a predetermined position.

[0037] In this embodiment, the valve packing 13 is made of ether-based urethane rubber, which has excellent abrasion resistance and mechanical strength, and has a hardness of 90 degrees. This improves the water-stopping performance of the valve piece packing 113, a problem with conventional antifreeze valves 101, and more reliably prevents water leakage. The material of the valve packing 13 is not limited to ether-based urethane rubber. It may be made of other materials that have excellent abrasion resistance and mechanical strength for use in high-pressure water, such as styrene-butadiene rubber (SBR). Furthermore, the valve packing 13 is not limited to thermosetting elastomers such as ether-based urethane rubber and styrene-butadiene rubber. It may be made of thermoplastic elastomers that have excellent abrasion resistance and mechanical strength. The hardness of the valve packing 13 is not limited to 90 degrees, as long as it does not pose a problem in abrasion resistance or mechanical strength. It is preferable that the corners between the peripheral edges of the upper and lower surfaces and the side surfaces of the valve packing 13 be chamfered to facilitate movement within the cylinder 2d.

[0038] In this embodiment, the antifreeze valve 1 has a spool valve structure (also called a piston-cylinder valve structure) in which the side surface 13a of the valve packing 13 and the inner wall of the cylinder 2d are in close contact with each other to provide a water-stopping function, as described above. However, the invention is not limited to this, and the water-stopping function may also be achieved by a flat valve structure (also called a positive valve structure). The flat valve structure provides a water-stopping function by the lower surface of the valve packing 13 being in close contact with the upper surface (valve seat) of the inlet of the high-pressure water. However, in the case of a flat valve structure, the valve packing 13 is pressed against the valve seat, which causes the valve packing 13 to wear out quickly, so a spool valve structure is more preferable from the standpoint of durability.

[0039] An O-ring 17 is attached to the shaft portion 11e of the valve body 11 to prevent high-pressure water from passing between the shaft portion 11e and the flow rate adjusting portion 14 and infiltrating upward.

[0040] As shown in Figures 2 and 3, the flow rate adjustment unit 14 has a generally cylindrical shape overall, with a through-hole 14a formed in the center, and is supported by the valve body 11 by inserting the shaft portion 11e into the through-hole 14a. The side surface 14c has four grooves 14d through which high-pressure water passes, as will be described later. The flow rate adjustment unit 14 has an upper surface 14b that abuts against the valve packing 13 when assembled into the valve body unit 10. The outer diameter of the side surface 14c is slightly smaller than the outer diameter of the valve packing 13 (the diameter of the side surface 13a), and is such that it does not come into contact with the inner diameter of the inner wall of the cylinder 2d.

[0041] The side surface 14c of the flow rate control unit 14 has four circumferentially arranged grooves 14d that are gradually deeper and wider from near the outer periphery of the upper surface 14b downward, i.e., in the direction away from the valve packing 13. The inner surfaces of the grooves 14d are formed so as to have a linear shape in every longitudinal cross section in the direction along the central axis of the flow rate control unit 14 (the direction L1-L1 in FIG. 3(b)), as shown in FIG. 3(b). Furthermore, the inner surfaces of the grooves 14d are formed so as to have an arc shape in every transverse cross section in the circumferential direction of the flow rate control unit 14 (the direction L2-L2 in FIG. 3(a)), as shown in FIG. 3(c). In other words, as shown in FIG. 3(d), the inner surface of groove 14d has a shape corresponding to a portion of the outer surface of a first cylinder coaxial with the central axis of through-hole 14a and a second cylinder inclined relative to the central axis of through-hole 14a, which appears at the portion extending inward from the side of the first cylinder when these cylinders intersect. When valve body unit 10 moves within cylinder 2d, the distance between the inner surface of groove 14d and the inner surface of cylinder 2d increases or decreases in proportion to the amount of movement of cylinder 2d (i.e., the valve opening). In other words, the total flow path cross-sectional area of ​​the four grooves 14d increases or decreases in proportion to the valve opening. Therefore, an antifreeze valve equipped with a flow control unit 14 having grooves 14d of this shape increases or decreases the flow rate in proportion to the valve opening. Furthermore, this shape facilitates cutting of flow control unit 14 using a tool such as an end mill.

[0042] The material of the flow rate control unit 14 is preferably a synthetic resin from the viewpoint of ease of cutting the grooves 14d, but is not limited to this and may be a metal. When the material of the flow rate control unit 14 is a synthetic resin, the grooves 14d may be formed by resin molding. The number of grooves 14d of the flow rate control unit 14 is not limited to four, but may be two, three, or five or more. The depth and width of the grooves 14d are not particularly limited, and may be any depth and width that allows the total flow path cross-sectional area of ​​the multiple grooves 14d to increase or decrease in proportion to the valve opening.

[0043] The flow rate adjustment unit 14 has four guides 14e. The guides 14e are formed to extend downward from near the outer periphery of the upper surface 14b and function to abut against the inner wall of the cylinder 2d when the valve packing 13 is separated from the cylinder 2d, thereby maintaining the orientation of the flow rate adjustment unit 14. A groove 14d is adjacent between adjacent guides 14e. Therefore, in accordance with the shape of the groove 14d, the guides 14e have a shape that gradually narrows from near the outer periphery of the upper surface 14b downward, i.e., in the direction away from the valve packing 13. Although not limited thereto, the lower end of the guide 14e is preferably located below the lower end of the shaft portion 11e of the valve body 11, and is long enough so that the guide 14e does not detach upward from the cylinder 2d even when the antifreeze valve 1 is in a water supply state (when the valve is fully open) at which the flow rate of high-pressure water is at its maximum.

[0044] The provision of guide 14e stabilizes the position of valve body unit 10 when it moves within cylinder 2d, making it easier to maintain watertight performance between valve packing 13 and cylinder 2d when water is drained, and also allows valve packing 13 and flow rate adjustment part 14 to accurately enter cylinder 2d when valve body unit 10 moves downward. The flow rate adjustment part 14 is required to be able to prevent damage to cylinder 2d even when it vibrates due to the flow of high-pressure water, and further to be able to maintain watertight performance and prevent the generation of vibration noise, and from this viewpoint, it is more preferable that it be made of synthetic resin.

[0045] The number of guides 14e is not limited to four, and may be two, three, five or more, as long as the above-mentioned functions are achieved. In addition, the number of grooves 14d formed between adjacent guides 14e is not limited to one, and may be two or more.

[0046] FIG. 5 is a perspective view of a flow rate adjustment unit 141 of a high-pressure water antifreeze valve according to another embodiment. While the flow rate adjustment unit 14 shown in FIG. 3 has one groove 14d between adjacent ones of the four guides 14e, the flow rate adjustment unit 141 shown in FIG. 5 has two grooves 141d between adjacent ones of the four guides 141e. There are eight grooves 141d in total, all of which have the same shape. However, the shapes of the grooves 141d are not limited to being the same; it is sufficient that the total flow path cross-sectional area of ​​the eight grooves 141d increases or decreases in proportion to the valve opening, and that an antifreeze valve including a flow rate adjustment unit 141 having grooves 141d of this shape increases or decreases the flow rate in proportion to the valve opening, and the increase or decrease in flow rate relative to the valve opening is appropriate.

[0047] 2. Operation of the high-pressure water antifreeze valve Next, the operation of the antifreeze valve 1 will be described. (Operation from draining state to supplying water) 1(a) in the drained state (fully closed state), the side surface 13a of the valve packing 13 of the valve body unit 10 is in close contact with the inner surface of the cylinder 2d of the valve box 2, so the flow path (communication port 2c) is closed and the high-pressure water flowing in from the inlet 2a of the valve box 2 is not supplied to the downstream piping or the snow machine. Also, in the drained state, the outer edge of the lower surface 12a of the stopper ring 12 of the valve body unit 10, i.e., the part that protrudes outward from the side surface 13a of the valve packing 13, is in close contact with the valve seat 2f provided on the upper surface of the cylinder 2d, thereby assisting the side surface 13a of the valve packing 13 in stopping the high-pressure water.

[0048] To transition from the water drain state to the water supply state, the drive unit connected to the antifreeze valve 1 is remotely operated to move the valve unit 10, which is connected to the drive unit, upward via the spindle 6, spindle joint 7, and center shaft 8. As the valve unit 10 moves upward, the side surface 13a of the valve packing 13 moves upward away from the cylinder 2d of the valve box 2, opening the flow path (communication port 2c). Water flowing in from the inlet 2a of the valve box 2 flows through the lower space 2b, the groove 14d of the flow rate adjustment unit 14, the communication port 2c, the upper space 2e, the riser pipe 3, and the outlet 4a of the upper fitting 4, and is supplied to the snow machine via the downstream piping connected to the outlet 4a. At this time, high-pressure water flows through the antifreeze valve 1, and the drain valve unit 20 is designed so that the force of the drain valve spring 24 is smaller than the force of the water pressure inside the antifreeze valve 1. This causes the ball 23 to tightly contact the O-ring 25, keeping the drain valve unit 20 closed. To change the amount of snow made by the snow machine, the drive unit connected to the antifreeze valve 1 is remotely operated to change the valve opening of the antifreeze valve 1, thereby adjusting the water pressure supplied to the snow machine.

[0049] (Operation from water supply state to water drain state) When the snow machine is finished using, the high-pressure water inside the antifreeze valve 1, as well as the downstream piping after the antifreeze valve 1 and the snow machine itself, is discharged to prevent freezing. First, in the water supply state shown in Figure 1(b), the drive unit connected to the antifreeze valve 1 is remotely operated to move the valve unit 10, which is connected via the spindle 6, spindle joint 7, and center shaft 8, downward. The outer edge of the lower surface 12a of the stopper ring 12 comes into close contact with the valve seat 2f, thereby completing the downward movement of the valve unit 10. As shown in Figure 1(a), the side surface 13a of the valve packing 13 comes into close contact with the cylinder 2d, closing the flow path (communication port 2c) and blocking the water supply from the inlet 2a to the upper space 2e.

[0050] 1(a), as the water pressure in the upper space 2e and below the antifreeze valve 1 decreases, the force of the drain valve spring 24 becomes greater than the force caused by the water pressure. Then, the ball 23, which had been in close contact with the O-ring 25, separates and opens the valve, and the water in the antifreeze valve 1 in the upper space 2e and below the valve body 2, as well as the water in the downstream piping and snow machine in the antifreeze valve 1, is discharged to the outside through the drain outlet 22b.

[0051] 3. Comparison of flow characteristics Fig. 6 is a graph comparing the flow characteristics of the valve body unit 10 of the antifreeze valve 1 according to one embodiment of the present invention with the flow characteristics when a flow control unit having a shape disclosed in a prior art patent document is used instead of the flow control unit 14 of the valve body unit 10, calculated by flow analysis. Fig. 7 is a cross-sectional view showing the configuration of the valve body unit and flow control unit used to calculate the flow characteristics in the graph of Fig. 6, with Fig. 7(a) showing a valve body unit incorporating a flow control unit having a shape disclosed in Patent Document 1 and Fig. 7(b) showing a valve body unit incorporating a flow control unit having a shape disclosed in Patent Document 2.

[0052] In the graph of Figure 6, the horizontal axis represents the valve opening of the antifreeze valve, and the vertical axis represents the flow rate of water discharged from the outlet of the antifreeze valve. Q1 represents the flow rate characteristics of an antifreeze valve having the valve unit 10 of the present invention, Q2 represents the flow rate characteristics of an antifreeze valve having the valve unit shown in Figure 7(a), and Q3 represents the flow rate characteristics of an antifreeze valve having the valve unit shown in Figure 7(b). Note that since each antifreeze valve has a different flow rate when fully open due to differences in structure, Figure 6 compares the flow rate percentages for each valve opening, with the flow rate when fully open being set to 100%. The analysis conditions for the analysis software used to analyze the flow rate characteristics were as follows: <Analysis model> A 1000mm pipe was installed on the inlet side. The pipe inner diameter is the same as the inlet diameter of the valve body ·Outflow side release <Fluid> H2O <Condition> Primary static pressure: 5101325Pa Secondary static pressure: 2101325Pa Stroke: 2mm intervals

[0053] When comparing at the same valve opening, the overall trend is that Q2, Q1, and Q3 have the highest flow rates. Also, for Q1, the valve opening and flow rate are roughly proportional between 5 and 25 mm, which is considered the most common valve opening for antifreeze valves, whereas for Q2, once the valve opening exceeds 5 mm, the change in flow rate relative to the change in valve opening becomes larger than at previous valve openings, and the valve opening and flow rate are no longer proportional. Furthermore, for Q2, even a small change in valve opening results in a large change in flow rate. For Q3, once the valve opening exceeds 15 mm, the change in flow rate relative to the change in valve opening becomes larger than at previous valve openings, and the valve opening and flow rate are no longer proportional.

[0054] Antifreeze valves with flow characteristics like Q2 have large changes in flow rate with even small changes in valve opening, making them difficult to adjust to the target flow rate and requiring a long time to achieve the target flow rate. Antifreeze valves with flow characteristics like Q3 allow for fine adjustments of the flow rate when the valve opening is small, making flow rate adjustment easy. However, the amount of change in valve opening required to achieve the target flow rate is large, meaning that many operations are required to move the valve (rotation using a handle in the case of manual operation, or rotation using a drive unit in the case of remote operation). This means that it takes a long time to achieve the target flow rate. On the other hand, once the valve opening exceeds a certain value, even small changes in valve opening cause large changes in flow rate, making it difficult to adjust to the target flow rate and requiring a long time to achieve the target flow rate. Flow rate adjustment is particularly difficult when valve opening and closing operations, including valve openings with large changes in flow rate trends, are required. [Explanation of symbols]

[0055] 1. Antifreeze valve for high-pressure water 2 Valve box 2a Inlet 2b Lower space 2c communication port 2d cylinder 2e Upper space 2f Valve seat 2g drain 2h female thread 3. Lifting pipe 3a male thread 3b male thread 4 Upper bracket 4a Outlet 4b female thread 4c female thread 5 grand 5a male thread 6 spindles 6a Shaft 6c Fitting protrusion 7 Spindle joint 7a Fitting recess 7b female thread 8 Middle Shaft 8a male thread 8b male thread 10 Valve unit 11 Valve body 11a Upper part 11b female thread 11c Recess 11d Tsubabe 11e Shaft 12 Stopper ring 12a Bottom side 13 Valve packing 13a side 14, 141 Flow rate adjustment section 14a Through hole 14b Top surface 14c side 14d, 141d groove 14e, 141e Guide 15 Washer 16 hexagon nuts 17 O-ring 20 Drain valve unit 21 Drain valve body 22 Drain plug 22b Drain outlet 23 ball 24 Drain valve spring 25 O-ring 101 Conventional antifreeze valve for high-pressure water 110 Valve unit 111 Valve body 111a female thread 111b recess 111c female thread 113 Valve piece gasket 113a Through hole 113d groove 113e Guide 113f Shoulder 116 Packing gland 116a male thread

Claims

1. a valve body having an inlet for high-pressure water therein; a valve body unit that moves within the inlet portion to open and close a flow path formed between the inlet portion and the valve body unit; Equipped with The valve body unit includes: a seal portion that closes the flow path by coming into close contact with the inlet portion and opens the flow path by moving away from the inlet portion; a flow rate adjusting section that is disposed in contact with the seal section and adjusts the flow rate of the high-pressure water flowing through the flow path; a valve body supporting the seal portion and the flow rate adjusting portion; and the flow rate adjusting portion has a plurality of circumferentially arranged grooves that are gradually deeper and wider in a direction away from the seal portion, an inner surface of each of the plurality of grooves has a linear shape in a direction along the central axis of the inlet portion and an arc shape in the circumferential direction; Antifreeze valve for high pressure water.

2. the flow rate adjusting portion has a plurality of guides that abut against the inlet portion to maintain the position of the flow rate adjusting portion when the seal portion is separated from the inlet portion. The antifreeze valve for high-pressure water according to claim 1.

3. One or more of the plurality of grooves are disposed between adjacent ones of the guides. The high-pressure water antifreeze valve according to claim 2.

4. The sealing portion closes the flow path by coming into close contact with an inner wall of the inlet portion, and opens the flow path by moving away from the inner wall. The antifreeze valve for high-pressure water according to claim 1.

5. The sealing portion is formed of an elastomer. The antifreeze valve for high-pressure water according to claim 1.

6. The elastomer is an ether-based urethane rubber or a styrene-butadiene rubber. The antifreeze valve for high-pressure water according to claim 5.

7. The valve body unit further includes a holding portion that holds the seal portion in a predetermined position by sandwiching the seal portion between itself and the flow rate adjusting portion. The antifreeze valve for high-pressure water according to claim 1.

8. The outer diameter of the seal portion is smaller than the outer diameter of the retaining portion, and a protruding portion of the retaining portion from the seal portion is in close contact with an upper surface of the inlet portion. The antifreeze valve for high-pressure water according to claim 7.

9. The material of the holding portion is synthetic resin or rubber. The antifreeze valve for high-pressure water according to claim 7.

10. The valve body has a flange portion that prevents the holding portion from expanding outward. The high-pressure water antifreeze valve according to claim 9.

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