Air bleed valve

Abstract

To provide an air bleed valve excellent in followability, having high abrasion resistance, and preventing operation obstruction by precipitation.SOLUTION: An air bleed valve includes: a body formed with an inflow port; a cap formed with an exhaust port; a float elevating according to a water level; an arm opening / closing the exhaust port by elevation of the float, and formed with a first groove and a second groove; and a wire spring for energizing the arm so as to close the exhaust port. The cap has a cylinder part and a wire spring fitting part formed with an insertion hole, and the arm has a packing for closing the exhaust port. The wire spring has two side parts fitted to the second groove, two insertion parts, and an intermediate part fitted to the first groove. Parts between parts of the side parts fitted to the second groove, and the insertion parts in the wire spring are elastically deformed at the cap side from the parts fitted to the second groove to the insertion parts, and the arm is energized so as to press the packing against the bottom edge of the cylinder part. A projectingly-curved surface is formed around an inlet of the insertion hole.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air vent valve that is attached to a tank, a pipe, etc., and that is used to discharge air from the tank, the pipe, etc. [Background technology]

[0002] To ensure smooth water supply to water storage tanks and to stabilize the liquid level in gas-liquid dissolving tanks, an air vent valve is installed on the top of the tank as a means of venting air from the tank. Air vent valves are also installed in piping through which liquid flows. Air vent valves sometimes use a mechanism that opens and closes the valve using a float that rises and falls depending on the water level.

[0003] For example, as in Patent Document 1, an air vent valve is known that uses a valve element connected to a float to close the air hole. As in Patent Document 2, an air vent valve is also known that uses a float itself as the valve element to close the air hole. In the air vent valve of Patent Document 1, when air flows into the valve body, the float descends, and the valve element connected to the float via a link mechanism opens the air outlet. Then, when the air is discharged and the water level rises, the float rises, and the valve element connected to the float closes the air outlet. Patent Document 1 uses a spring that biases the valve element in the closing direction.

[0004] In the air vent device of Patent Document 2, the float itself is the valve body, so when air flows into the valve body and the float descends, the air hole opens and the air is discharged. Then, when the air is discharged and the float rises, the float itself closes the air hole. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-40637 [Patent Document 2] Japanese Patent Application Publication No. 7-19360 Summary of the Invention [Problem to be solved by the invention]

[0006] When an air vent valve is installed in a tank, pipe, or the like that uses seawater, precipitates may cause malfunctions in components such as the link mechanism and coil spring of the air vent valve of Patent Document 1. In addition, spring materials must be used for the coil spring, and there is a problem in that it is difficult to use highly corrosion-resistant materials such as high-nickel alloys and titanium, which are unsuitable for spring materials, for the coil spring, even if they have excellent corrosion resistance.

[0007] Even if an air vent valve configuration in which the float itself functions as the valve element, as in Patent Document 2, is used in tanks, piping, etc. that use seawater, problems due to deposits do not occur. However, in cases where there is a rapid exchange of air and water intrusion, such as in a gas-liquid dissolution tank, the float itself functions as the valve element, and the movement of the float directly affects the opening and closing of the valve. Therefore, if the float's response to the water level is delayed, the opening and closing of the valve will be delayed, causing delays in air release and water leakage, and the air vent valve may not function properly.

[0008] Therefore, an object of the present invention is to provide an air vent valve that has excellent followability and high wear resistance and can prevent operation from being hindered by deposits. [Means for solving the problem]

[0009] An air vent valve according to a first aspect of the present invention comprises a main body having an open top and an inlet formed at its bottom end, a cap attached to the top end of the main body and formed with an exhaust port for discharging air from the main body, a float housed within the main body and rising and falling according to the level of liquid in the main body, an arm positioned above the float, opening and closing the exhaust port as the float rises and falls and having a first groove and two second grooves formed therein, and a wire spring attached to the arm, rotatably holding the arm relative to the cap and biasing the arm to close the exhaust port. The cap has a cylindrical portion formed around the exhaust port so as to protrude downward and having a sealing surface formed at its bottom end, and two wire spring mounting portions formed with insertion holes into which both ends of the wire spring are inserted. The float has a pressing portion that presses the pivoting tip of the arm downward when the float descends. The arm has a packing for closing the exhaust port and two protruding portions protruding laterally from both side surfaces. The packing is disposed on the upper surface of the arm near the base end of the rotation, the first groove crossing the upper surface of the arm near the tip end of the rotation from the protruding portion, and the two second grooves vertically crossing the lower surfaces of the two protruding portions. The wire spring has two side portions respectively fitted into the two second grooves, two insertion portions bent at approximately right angles near the base end of the rotation from the two side portions and inserted into the insertion hole, and one intermediate portion fitted into the first groove and connecting the tip end sides of the two side portions. The portion of the wire spring between the portion of the side portion fitted into the second groove and the insertion portion elastically deforms toward the cap from the portion fitted into the second groove toward the insertion portion, thereby biasing the arm toward the cylindrical portion so that the packing is pressed against the lower end of the cylindrical portion. A convex curved surface is formed around the entrance of the insertion hole of the wire spring attachment portion.

[0010] An air vent valve having such a configuration can eliminate small gaps between the wire spring and the wire spring mounting portion of the cap where deposits can accumulate.

[0011] In the air vent valve pertaining to the second aspect of the present invention, the cap has a stopper protruding downward from the bottom surface, and when the pivoting tip end side of the top surface of the arm abuts against the stopper, the exhaust port is closed by the packing.

[0012] In the air vent valve according to the third aspect of the present invention, the two sides of the wire spring each have a first side connected to the insertion portion, a second side connected to the intermediate portion and attached to the second groove, and a third side connecting the first side and the second side, and the distance between the two first sides is wider than the distance between the two second sides.

[0013] In the air vent valve according to a fourth aspect of the present invention, the pressing portion includes a bar that comes into contact with the upper surface of the arm on the side of the tip of the arm that rotates, and a support column that supports the bar. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an air vent valve that has excellent followability and high abrasion resistance and is capable of preventing operation from being hindered by deposits. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a cross-sectional view of the air vent valve in a closed state. [Figure 2] FIG. [Figure 3] FIG. 2 is an enlarged view of part A in FIG. [Figure 4] FIG. 10 is a bottom view of the cap with the arm and wire spring attached. [Figure 5] FIG. 10 is a schematic diagram of the inside of the air vent valve as viewed from the side of the rotation tip of the arm. [Figure 6] FIG. [Figure 7] 1A and 1B are diagrams showing a wire spring in a state where the wire spring is not elastically deformed, in which (A) is a plan view of the wire spring and (B) is a side view of the wire spring. [Figure 8]10 is a view of the cap with the arm and wire spring attached, viewed from the base end of the arm's rotation. FIG. [Figure 9] FIG. 4 is a partially enlarged view of the inside of the air vent valve in a closed state. [Figure 10] FIG. 10 is a partial cross-sectional view of the air vent valve in an open state. [Figure 11] FIG. 4 is a partially enlarged view of the inside of the air vent valve in an open state. DETAILED DESCRIPTION OF THE INVENTION

[0016] An air vent valve 1 according to an embodiment of the present invention will be described below with reference to the drawings. As shown in Fig. 1, the air vent valve 1 of this embodiment comprises a main body 2, a cap 3, a float 4, an arm 5, and a wire spring 6. The air vent valve 1 of this embodiment is used to vent air from a water storage tank, a gas-liquid dissolving tank, etc.

[0017] The main body 2 of this embodiment has a substantially cylindrical shape. As shown in Fig. 1, the main body 2 is open at the top and has an inlet 21 formed at the bottom. The main body 2 is disposed above a water storage tank, a gas-liquid dissolving tank, etc., and the inlet 21 is connected to the water storage tank, the gas-liquid dissolving tank, etc. via piping, etc.

[0018] A substantially rectangular flange 24 for attaching the cap 3 is formed on the outer periphery of the upper end of the main body 2. An annular groove 22 is formed in the upper end of the main body 2 so as to surround the opening. As shown in FIG. 1, an O-ring 23 is fitted in the groove 22.

[0019] As shown in Fig. 1, the cap 3 is attached to the upper end of the main body 2 using bolts or the like. An O-ring 23 seals the gap between the upper end of the main body 2 and the underside of the cap 3. As shown in Fig. 2, the cap 3 has a substantially rectangular shape. Through holes 35 for attaching the cap 3 to the main body 2 with bolts are provided in the four corners of the cap 3.

[0020] The cap 3 is formed with an exhaust port 31 for discharging air from the main body 2 to the outside. As shown in FIGS. 1 and 3, the exhaust port 31 penetrates the cap 3 from top to bottom. The cap 3 has a tubular portion 32, two wire spring mounting portions 33, and a stopper 34. The tubular portion 32 is formed on the lower surface of the cap 3 so as to protrude downward around the exhaust port 31. Furthermore, the tubular portion 32 is formed on the upper surface of the cap 3 so as to protrude upward around the exhaust port 31. As shown in FIGS. 2 and 3, a sealing surface 32a is formed at the lower end of the tubular portion 32. The sealing surface 32a is formed around the entrance of the exhaust port 31 and has a curved surface that protrudes downward. As shown in FIG. 3, the entrance of the exhaust port 31 is located at the lowest end of the curved surface of the sealing surface 32a.

[0021] As shown in FIG. 2, the two wire spring mounting portions 33 are arranged on the underside of the cap 3 with the tubular portion 32 sandwiched between them. The wire spring mounting portions 33 are formed with insertion holes 33a into which insertion portions 61, which are both ends of the wire spring 6 described below, are inserted. The central axes of the insertion holes 33a of the two wire spring mounting portions 33 are arranged on the same line. As shown in FIG. 3, the lower end of the exhaust port 31 is located at approximately the same height as the central axes of the two insertion holes 33a. As shown in FIG. 4, the arm 5 is arranged between the two wire spring mounting portions 33.

[0022] The two wire spring mounting portions 33 have opposing first surfaces 331 and second surfaces 332 opposite the first surfaces 331. In this embodiment, as shown in FIG. 4 , the entrances of insertion holes 33a into which both ends of the wire spring 6 are inserted are located on the second surfaces 332 of the two wire spring mounting portions 33. A convex curved surface portion 33b is formed around the entrance of the insertion hole 33a on the second surface 332 of the wire spring mounting portion 33. The entrance of the insertion hole 33a is located at the apex of the convex curved surface portion 33b. The shape of the convex curved surface portion 33b can be a truncated cone, a hemispherical surface, a partial spherical surface, or the like. A configuration in which a convex curved surface portion is provided on the first surface 331 and both ends of the wire spring 6 are inserted from the first surface 331 side is also possible.

[0023] In this embodiment, the convex curved surface portion 33b has a truncated cone shape. The portion of the second surface 332 above the convex curved surface portion 33b has a flat shape. The convex curved surface portion 33b is provided to prevent the operation of the wire spring 6 from being hindered due to deposits being formed between the wire spring 6 and the wire spring mounting portion 33. Therefore, it is sufficient to form the convex curved surface portion 33b on the second surface 332 in at least an area that affects the operation of the wire spring 6.

[0024] As shown in Fig. 1, the stopper 34 protrudes downward from the bottom surface of the cap 3. As shown in Fig. 1, the pivoting tip of the arm 5 is disposed below the stopper 34. The bottom end of the stopper 34 is at the same height as the bottom end of the cylindrical portion 32. As a result, when the top surface of the arm 5 abuts against the bottom end of the stopper 34, the arm 5 becomes horizontal.

[0025] The float 4 is housed in the main body 2 and is capable of rising and falling according to the water level. As shown in Fig. 1, the float 4 has a pressing part 41 that presses the tip end of the arm 5 downward when the float 4 descends. As shown in Fig. 5, the pressing part 41 includes two support posts 41a and a bar 41b supported by the two support posts 41a. The bar 41b is in contact with the upper surface of the tip end of the arm 5.

[0026] The arm 5 has a packing 51 that closes the exhaust port 31 and two protruding portions 54 that protrude laterally from both side surfaces. The packing 51 is provided on the upper surface of the arm 5 on the base end side of rotation. As shown in FIG. 6 , in this embodiment, the packing 51 has a circular shape. Furthermore, a cylindrical protrusion 51a that protrudes downward is formed on the underside of the packing 51. The packing 51 is fitted into a stepped through-hole 52 formed in the arm 5. The packing 51 functions as a valve that closes the exhaust port 31.

[0027] 6, the first groove 53 crosses the upper surface of the tip end of the arm 5. The second groove 55 crosses the lower surface of the protruding portion 54. The arm 5 does not have a hinge or the like formed thereon for attaching it to the cap 3.

[0028] As shown in FIG. 7, the wire spring 6 has two insertion portions 61, one intermediate portion 62, and two side portions 63. The two insertion portions 61 are each bent at approximately right angles closer to the rotation base end than the side portions 63. As shown in FIG. 4, the insertion portions 61 are inserted into the insertion holes 33a of the wire spring attachment portion 33. By inserting the insertion portions 61 into the insertion holes 33a, the wire spring 6 is attached to the cap 3 so as to be rotatable around the insertion portions 61 as an axis. The intermediate portion 62 connects the rotation tip ends of the two side portions 63. The intermediate portion 62 is attached to the first groove 53 of the arm 5.

[0029] As shown in Fig. 7, each of the two side portions 63 includes a first side portion 63a connected to the insertion portion 61, a second side portion 63b connected to the middle portion 62, and a third side portion 63c connecting the first side portion 63a and the second side portion 63b. As shown in Fig. 7(A), the wire spring 6 has a shape that is bent within a single plane. As shown in Fig. 7(B), when no external force is applied, the wire spring 6 is straight when viewed from the side. The first side portion 63a is connected to the insertion portion 61 at a substantially right angle, and the second side portion 63b is connected to the middle portion 62 at a substantially right angle.

[0030] As shown in Fig. 7(A), the distance between the two parallel-arranged first side portions 63a is wider than the distance between the two parallel-arranged second side portions 63b. The third side portion 63c is connected to the first side portion 63a and the second side portion 63b at a substantially right angle. As shown in Fig. 4, the second side portion 63b is attached to the second groove 55 of the arm 5. The first side portion 63a is spaced from the side surface of the arm 5 and is located on the second surface 332 side of the wire spring attachment portion 33.

[0031] The wire spring 6 is formed by bending a single wire material. There are no particular limitations on the material of the wire spring 6, and metal, which is a conventional spring material, can be used.

[0032] 4, the wire spring 6 is fitted into the arm 5 by fitting the middle portion 62 into the first groove 53 and the two second side portions 63b into the two second grooves 55. The depths of the first groove 53 and the two second grooves 55 are set so that the central axis of the middle portion 62 and the central axis of the second side portions 63b are positioned at the same height (on the same plane) with respect to the arm 5.

[0033] When the insertion portion 61 of the wire spring 6 is inserted into the insertion hole 33a with the wire spring 6 fitted into the arm 5, the arm 5 is attached to the cap 3 by the wire spring 6, as shown in Figures 1 and 8. In this way, the arm 5 is attached to the cap 3 so as to be rotatable around the vicinity of the lower end (near the entrance) of the insertion hole 33a.

[0034] When the arm 5 is attached to the cap 3 by the wire spring 6, the insertion portion 61 is raised above the upper surface of the arm 5, as shown in Fig. 9. Therefore, when the wire spring 6 is viewed from the side, as shown in Fig. 9, the portion of the wire spring 6 on the rotation base end side that protrudes from the second groove 55, in this embodiment, the first side portion 63a, is elastically deformed from the vicinity of the third side portion 63c towards the insertion portion 61 and toward the cap 3, and the wire spring 6 is in a bent state.

[0035] The elastic force of the wire spring 6, which is bent while attached to the cap 3, acts on the arm 5 in a direction that rotates the tip of the rotation clockwise in Fig. 1 so that the packing 51 closes the exhaust port 31. The wire spring 6 urges the arm 5, pressing the packing 51 against the sealing surface 32a and closing the exhaust port 31. At this time, as shown in Fig. 1, the upper surface of the arm 5 abuts against the stopper 34 of the cap 3, and the arm 5 cannot rotate upward.

[0036] The arm 5 does not have a hinge or the like, and is rotatably attached to the cap 3 only by the wire spring 6. The wire spring 6 has an insertion portion 61 inserted into the insertion hole 33a. As a result, the arm 5 is rotatably attached to the cap 3 without having a sliding portion near the lower end (near the entrance) of the exhaust port 31. The arm 5 rotates while moving along the seal surface 32a, and the center of rotation of the arm 5 moves.

[0037] When the insertion portion 61 of the wire spring 6 is inserted into the insertion hole 33a, the first side portion 63a comes into contact with the edge of the entrance of the insertion hole 33a, as shown in Figure 8. However, a convex curved surface portion 33b exists around the entrance of the insertion hole 33a, and the first side portion 63a comes into contact with the wire spring attachment portion 33 only at the edge of the entrance of the insertion hole 33a. This prevents a small gap from existing between the wire spring 6 and the wire spring attachment portion 33.

[0038] The arm 5 is attached to the cap 3 by the wire spring 6, and the pressing portion 41 of the float 4 is hooked onto the arm 5, thereby combining the float 4 with the cap 3, the arm 5, and the wire spring 6. At this time, the arm 5 is rotated slightly downward to pass the bar 41b of the pressing portion 41 between the arm 5 and the stopper 34.

[0039] When the float 4 and the arm 5 are combined, as shown in Figure 5, the tip of the arm 5 is positioned below the bar 41b of the pressing part 41. The bar 41b is in contact with the part of the upper surface of the arm 5 that is closer to the base end of the rotation than the first groove 53. As the arm 5 rotates in conjunction with the rise and fall of the float 4, the position of the upper surface of the arm 5 that contacts the pressing part 41 moves, but the pressing part 41 is positioned on the float 4 so that the arm 5 does not separate from the pressing part 41.

[0040] With the cap 3, float 4, arm 5 and wire spring 6 assembled, the float 4 is inserted into the main body 2 and the cap 3 is fixed to the main body 2 with bolts or the like to complete the air vent valve 1. When the inlet 21 of the main body 2 is connected to a water tank, a gas-liquid dissolving tank or the like, the air vent valve 1 is ready for use.

[0041] The operation of the air vent valve 1 will be explained using the drawings. In the state shown in Figures 1 and 3, the exhaust port 31 is closed by the packing 51. At this time, liquid flows into the main body 2 from the inlet 21, causing the water level (the area shaded with dots in Figure 1) to rise, and the float 4 also rises in accordance with the water level. The arm 5 is horizontal, and as soon as the packing 51 closes the exhaust port 31, the upper surface of the arm 5 abuts against the stopper 34. In this way, the air vent valve 1 is in a closed state.

[0042] 1 and 3, when air flows into the main body 2 from a pump or the like through the inlet 21 while the air vent valve 1 is closed, air accumulates in the upper part of the main body 2. As the amount of air accumulated in the upper part of the main body 2 increases, the water level in the main body 2 (the area shaded with dots in FIGS. 10 and 11) drops, and the float 4 also drops in accordance with the water level.

[0043] As the float 4 descends, the pressing portion 41 presses downward on the upper surface of the tip end of the arm 5, causing the arm 5, which is held by the wire spring 6, to rotate downward, as shown in Figures 10 and 11. As the arm 5 rotates downward, the packing 51 moves away from the entrance of the exhaust port 31, opening the exhaust port 31, as shown in Figure 10. When the exhaust port 31 opens, the air inside the main body 2 is discharged to the outside through the exhaust port 31. In this way, the air vent valve 1 opens, allowing the air inside the main body 2 to be discharged.

[0044] When the exhaust port 31 is closed by the packing 51, as viewed from the side as shown in Fig. 3, the upper surface of the arm 5 (the upper surface of the packing 51) is located at approximately the same position as the insertion portion 61, which serves as the rotation center of the wire spring 6. However, when the arm 5 rotates downward and the packing 51 moves away from the exhaust port 31, as viewed from the side as shown in Fig. 10, the rotation center of the arm 5 moves toward the base end of the arm 5 (to the right in Fig. 10) of the insertion portion 61, which serves as the rotation center of the wire spring 6, and the upper surface of the arm 5 becomes distant from the insertion portion 61 of the wire spring 6. For this reason, the amount of deflection (amount of elastic deformation) of the wire spring 6 increases as the rotation angle of the arm 5 increases, and the wire spring 6 constantly biases the arm 5 to rotate upward.

[0045] When the air inside the main body 2 is exhausted, liquid flows into the main body 2 through the inlet 21, causing the water level inside the main body 2 (the area shaded with dots in FIG. 10) to rise. As the water level inside the main body 2 rises, the float 4 also rises. The arm 5, which had been rotated downward by the pressing portion 41, rotates upward due to the action of the wire spring 6 as the float 4 rises. When the arm 5 rotates upward and the packing 51 abuts against the sealing surface 32a, the exhaust port 31 is closed again, as shown in FIGS. 1 and 3. At this time, the upper surface of the arm 5 abuts against the stopper 34, the arm 5 becomes horizontal, and the center of rotation of the arm 5 and the insertion portion 61, which is the center of rotation of the wire spring 6, are again in approximately the same position.

[0046] By repeatedly performing this operation, the air vent valve 1 of this embodiment can discharge air from a water storage tank, a gas-liquid dissolution tank, etc. to which the air vent valve 1 is connected, and stabilize the liquid level in the tank.

[0047] The arm 5 of the air vent valve 1 of this embodiment does not have a hinge or the like, and furthermore does not have a sliding part near the lower end (near the inlet) of the exhaust port 31, and is rotatably attached to the cap 3 by a wire spring 6. This eliminates the problem of precipitates impeding the movement of the sliding part even when the air vent valve 1 is used in an environment such as seawater.

[0048] Furthermore, in the air vent valve 1 of this embodiment, the insertion hole 33a into which the insertion portion 61 of the wire spring 6 is inserted is surrounded by a convex curved surface portion 33b, so the only part of the wire spring 6 that comes into contact with the wire spring mounting portion 33 is the edge of the entrance to the insertion hole 33a. As such, the area where the wire spring 6 comes into contact with the wire spring mounting portion 33 is very small, which reduces wear on the wire spring 6. Furthermore, there are no small gaps between the wire spring 6 and the wire spring mounting portion 33 where deposits can accumulate, so it is possible to prevent deposits from impeding the movement of the wire spring 6.

[0049] In this way, even when the air vent valve 1 of this embodiment is used in an environment where deposits such as seawater are formed, the movement of the arm 5 is not easily hindered, and the valve can be opened and closed smoothly. [Industrial Applicability]

[0050] The present invention is applicable to air vent valves for water storage tanks, gas-liquid dissolving tanks, etc. [Explanation of symbols]

[0051] 1 Air vent valve 2 Main unit 21 Inlet 22 Groove 23 O-ring 24 flange 3 Cap 31 Exhaust port 32 Cylinder part 32a sealing surface 33 Wire spring mounting part 33a Insertion hole 33b Convex curved part 34 Stopper 35 through holes 4. Float 41 Pressing section 41a Post 41b Bar 5 Arm 51 Gasket 52 Through hole 53 First groove 54 Overhang 55 2nd groove 6 wire springs 61 Insertion section 62 Middle section 63 Side 63a First side 63b Second side 63c Third side

Claims

1. a main body having an open top and an inlet formed at a bottom end; a cap attached to an upper end of the main body and having an exhaust port formed therein for discharging air from inside the main body; a float housed within the body and rising and falling according to the level of liquid within the body; an arm disposed above the float, opening and closing the exhaust port in response to the rise and fall of the float, the arm having a first groove and two second grooves formed therein; a wire spring attached to the arm, rotatably holding the arm relative to the cap, and biasing the arm to close the exhaust port; the cap has a cylindrical portion formed around the exhaust port so as to protrude downward and having a sealing surface formed at its lower end, and two wire spring mounting portions formed with insertion holes into which both ends of the wire spring are inserted, The float has a pressing portion that presses the tip end of the arm downward when the float descends, the arm has a packing for closing the exhaust port and two protruding portions protruding laterally from both side surfaces, the packing is disposed on an upper surface of the arm on the rotation base end side, the first groove crosses the upper surface of the arm on the rotation tip end side of the protruding portion, and the two second grooves cross the lower surfaces of the two protruding portions, respectively, vertically; the wire spring has two side portions respectively fitted into the two second grooves, two insertion portions which are bent at approximately right angles on the rotation base end side of the two side portions and inserted into the insertion hole, and one intermediate portion which is fitted into the first groove and connects the rotation tip end sides of the two side portions, a portion of the wire spring between the portion of the side portion attached to the second groove and the insertion portion is elastically deformed toward the cap from the portion attached to the second groove toward the insertion portion, and thereby the arm is biased so that the packing closes the exhaust port; a convex curved surface portion is formed around the entrance of the insertion hole of the wire spring attachment portion; An air vent valve characterized by:

2. The cap has a stopper protruding downward from a bottom surface thereof, When the rotation tip side of the upper surface of the arm abuts against the stopper, the exhaust port is closed by the packing.

2. The air vent valve according to claim 1.

3. the two side portions of the wire spring each include a first side portion connected to the insertion portion, a second side portion connected to the intermediate portion and fitted in the second groove, and a third side portion connecting the first side portion and the second side portion, The distance between the two first sides is greater than the distance between the two second sides.

3. The air vent valve according to claim 1 or 2.

4. The pressing portion includes a bar that abuts against an upper surface of the arm at the tip end of the rotation, and a support column that supports the bar.

3. The air vent valve according to claim 1 or 2.

Images