Valve unit and booster valve

Abstract

To provide a valve unit that can prevent dew condensation at low cost.SOLUTION: A valve unit 10 comprises: a main valve 12 that alternately connects an exhaust port 14a and a compressed air supply source 22 to a compressed air device; a main valve casing 14 that houses the main valve 12; a dew condensation prevention cover 16 that covers the outside of the main valve casing 14 and forms a cover air flow path 18 together with the main valve casing 14; and a cover air supply port 32 that communicates with one end of the cover air flow path 18 and supplies a portion of compressed air supplied from the compressed air supply source 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a valve unit and a booster valve that supply and discharge compressed air. [Background technology]

[0002] A valve unit equipped with a switching valve is used to supply and exhaust air to pneumatic equipment such as an air cylinder. For example, Patent Document 1 discloses a valve unit that performs switching operation using an electric signal and pilot air. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 036046 Summary of the Invention [Problem to be solved by the invention]

[0004] When a valve unit supplies or discharges compressed air at a relatively high pressure at a relatively high frequency, a temperature drop occurs due to the adiabatic expansion of the compressed air passing through it. While there is no limitation on the use of the valve unit, for example, a valve unit that supplies or discharges compressed air for operating a pressure booster valve (air booster) that increases the pressure of the compressed air is prone to temperature drop.

[0005] Depending on the installation environment of the valve unit, the surface temperature of the valve unit may fall below the dew point of the outside air, causing condensation. The occurrence of condensation depends on the region where the valve unit is installed, the season, and other conditions. Condensation does not occur frequently, so it is not currently recognized as a major problem. Furthermore, condensation is considered a natural phenomenon that occurs depending on the installation environment of the valve unit. For this reason, no efforts have been made to address condensation by improving the valve unit itself.

[0006] However, if condensation could be prevented at low cost without reducing the performance and efficiency of the valve unit and its connected equipment, it could potentially reduce the burden on users of cleaning work, etc., or improve the cleanliness of the installation location.

[0007] An object of the present invention is to solve the above-mentioned problems. [Means for solving the problem]

[0008] A first aspect of the present disclosure is a valve unit having a main valve that alternately connects an exhaust port and a compressed air supply source to a compressed air device, a main valve housing that houses the main valve, a condensation prevention cover that covers the outside of the main valve housing and forms a cover air flow path between the main valve housing and the cover air supply port, which communicates with one end of the cover air flow path and supplies a portion of the compressed air supplied from the compressed air supply source.

[0009] A second aspect of the present disclosure is a booster valve including the valve unit according to the first aspect. [Effects of the Invention]

[0010] The valve unit and booster valve described above use compressed air with a low dew point temperature as cover air to flow around the main valve housing, thereby preventing condensation on the valve unit even if the temperature of the main valve housing drops. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating the configuration of a valve unit according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating the configuration of a valve unit according to the second embodiment. [Figure 3] FIG. 3 is a perspective view of a booster valve according to a third embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a perspective view of a booster valve according to a fourth embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) As shown in Fig. 1, this valve unit 10 is used to control the drive of compressed air equipment such as an air cylinder 20. The valve unit 10 is connected to a compressed air supply source 22, an exhaust port 24, and the air cylinder 20. A piston chamber 26 of the air cylinder 20 is divided by a piston 28 into a head-side pressure chamber 26a and a rod-side pressure chamber 26b. A head-side flow path 27a is connected to the head-side pressure chamber 26a, and a rod-side flow path 27b is connected to the rod-side pressure chamber 26b. The air cylinder 20 is driven by compressed air supplied to and exhausted from the head-side pressure chamber 26a and the rod-side pressure chamber 26b.

[0013] The connection target of the valve unit 10 is not limited to the illustrated air cylinder 20, but may be any type of pneumatic equipment that alternately supplies and discharges compressed air. Here, the valve unit 10 will be described using the example of being connected to the illustrated air cylinder 20.

[0014] The valve unit 10 includes a main valve 12, a main valve housing 14, a condensation prevention cover 16, and a cover air flow path 18. The main valve 12 is, for example, a five-port valve. In the illustrated first position, the main valve 12 connects a compressed air supply source 22 to the rod-side pressure chamber 26b and connects an exhaust port 24 to the head-side pressure chamber 26a. In the second position, the main valve 12 connects the exhaust port 24 to the rod-side pressure chamber 26b and connects the compressed air supply source 22 to the head-side pressure chamber 26a. The main valve 12 is, for example, a solenoid valve, and is switched between the first and second positions by the supply of a drive current. The main valve 12 drives the air cylinder 20 by alternately switching between the first and second positions.

[0015] The main valve housing 14 houses the main valve 12. The main valve housing 14 houses the flow path of the main valve 12 and a spool, which is an example of the main valve 12. A compressed air supply source 22 is connected to the main valve housing 14 through a compressed air flow path 22a. An exhaust port 24 is also connected to the main valve housing 14 through an exhaust flow path 24a. The compressed air that passes through the main valve 12 and the main valve housing 14 and is discharged from the exhaust port 24 is also referred to as exhaust air in the following description. The exhaust air expands adiabatically inside the main valve housing 14 and the main valve 12, causing a decrease in temperature. The decrease in temperature of the exhaust air cools the main valve housing 14. When the air cylinder 20 becomes larger and the volumes of the head-side pressure chamber 26a and the rod-side pressure chamber 26b increase, the flow rate of exhaust air increases, making it easier to cool the main valve housing 14. Furthermore, as the number of operating cycles of the air cylinder 20 increases (as the frequency of reciprocation increases), the flow rate of exhaust air passing through the inside of the main valve housing 14 increases, decreasing the surface temperature of the main valve housing 14. Furthermore, as the pressure of the compressed air increases, the temperature drop of the exhaust air increases, making it easier for the surface temperature of the main valve housing 14 to decrease.

[0016] An exhaust port 14a is provided in the main valve housing 14. An exhaust flow path 24a is connected to the exhaust port 14a. Exhaust air that has passed through the main valve housing 14 passes through the exhaust port 14a and the exhaust flow path 24a and is discharged to the atmosphere from the exhaust port 24. The exhaust port 14a and the exhaust flow path 24a are isolated from the cover air flow path 18. Therefore, in this embodiment, the exhaust air does not substantially flow into the cover air flow path 18.

[0017] The condensation prevention cover 16 is disposed so as to cover the outside of the main valve housing 14. The condensation prevention cover 16 is spaced apart from the surface of the main valve housing 14, and a cover air flow path 18 for flowing cover air is formed between the condensation prevention cover 16 and the main valve housing 14. Note that a portion of the condensation prevention cover 16 may be connected to the main valve housing 14. The condensation prevention cover 16 is formed from a material with low thermal conductivity (a material that does not easily transfer heat). Examples of materials for the condensation prevention cover 16 include various resins.

[0018] The cover air flow path 18 communicates with a cover air supply port 32 at a predetermined location. The cover air supply port 32 (exhaust port of the pilot piston 42b) supplies cover air to the cover air flow path 18. The cover air supply port 32 may be provided in the condensation prevention cover 16 or in the main valve housing 14. The cover air supply port 32 may also be provided in the device to which the valve unit 10 is connected.

[0019] A cover air exhaust port 34 is provided at one end of the condensation prevention cover 16. The cover air that flows through the cover air flow path 18 is discharged from the cover air exhaust port 34. The position of the cover air exhaust port 34 is preferably away from the position of the cover air supply port 32. With this configuration, the cover air spreads inside the cover air flow path 18 and flows to cover the entire area of ​​the main valve housing 14, thereby effectively preventing condensation. Note that if the cover air exhaust port 34 is located near the cover air supply port 32, the cover air will be discharged from the cover air exhaust port 34 before it can spread, which may reduce the condensation prevention effect of the cover air.

[0020] The cover air flow path 18 is formed to surround the outer surface of the main valve housing 14. A portion of the compressed air is supplied to the cover air flow path 18 as cover air. The cover air is supplied to the cover air flow path 18 through a branch flow path 22b branching from the compressed air flow path 22a. An orifice 38 is provided in the branch flow path 22b to throttle the flow rate of the cover air. Because the pressure inside the cover air flow path 18 is approximately the same as atmospheric pressure, the compressed air expands adiabatically as it passes through the orifice 38, lowering its temperature. However, the flow rate of the cover air is much smaller than the flow rate of the exhaust air, and therefore does not substantially lower the temperature of the condensation prevention cover 16. Therefore, the cover air flows around the main valve housing 14 without causing condensation on the condensation prevention cover 16 itself.

[0021] The valve unit 10 of this embodiment is configured as described above. The valve unit 10 of this embodiment is provided with a condensation prevention cover 16 that covers the outside of the main valve housing 14, and supplies part of the compressed air as cover air to a cover air flow path 18 between the condensation prevention cover 16 and the main valve housing 14.

[0022] Compressed air is generated by compressing atmospheric air with a compressor, and moisture is removed on the way to the valve unit 10 connected to the use end line. Therefore, the dew point temperature of the compressed air returned to atmospheric pressure is extremely low, for example, about -14°C to -23°C. Therefore, using compressed air as cover air prevents condensation on the main valve housing 14.

[0023] The cover air may be compressed air that has passed through any route as long as it does not excessively cool the condensation prevention cover 16. Therefore, in the illustrated example, the compressed air taken out from the branch flow path 22b is used as the cover air, but the present embodiment is not limited to this example.

[0024] One variation, for example, may have the main valve housing 14 incorporate the branch passage 22b and the orifice 38. Another variation may utilize a portion of the exhaust air as cover air.

[0025] (Second embodiment) As shown in Fig. 2, the basic configuration of a valve unit 10A of this embodiment is similar to that of the valve unit 10 shown in Fig. 1. In Fig. 2, the same components as those in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. The valve unit 10A differs from the valve unit 10 of Fig. 1 in the main valve 12A. The main valve 12A is driven by pilot air. Therefore, the valve unit 10A includes, in addition to the main valve 12A, a pilot valve 40 that supplies and discharges pilot air.

[0026] 2, the main valve 12A includes a return member 42a and a pilot piston 42b for switching between a first position and a second position. The pilot piston 42b receives a supply of pilot air and switches the main valve 12A from the first position to the second position. Pilot air is supplied to and discharged from the pilot piston 42b through a pilot flow path 44. The return member 42a returns the main valve 12A to the first position when the pilot air in the pilot piston 42b is discharged.

[0027] The pilot valve 40 is a three-port valve connected to the branch flow path 22b, the pilot flow path 44, and the pilot air discharge flow path 36. The pilot valve 40 is a solenoid valve. The pilot valve 40 is displaced to the discharge position shown in the figure by the elastic force of the elastic member 40b, and is displaced to the supply position by being driven by the electromagnetic actuator 40a. In the discharge position, the pilot valve 40 connects the pilot flow path 44 and the pilot air discharge flow path 36, and discharges the pilot air from the pilot piston 42b through the cover air supply port 32.

[0028] The pilot valve 40 is switched to a supply position by being driven by an electromagnetic actuator 40a. In the supply position, the pilot valve 40 connects the branch flow path 22b to a pilot flow path 44. The branch flow path 22b is connected to the compressed air supply source 22 and supplies a portion of the compressed air as pilot air to the pilot flow path 44. The supplied pilot air drives a pilot piston 42b, displacing the main valve 12A from the first position to the second position.

[0029] The valve unit 10A of this embodiment is configured as described above. The valve unit 10A has a main valve 12A that is driven by pilot air. The pilot piston 42b of the main valve 12A discharges pilot air into the pilot flow path 44 when the main valve 12A switches from the second position to the first position. The discharged pilot air is discharged to the cover air supply port 32 through the pilot valve 40 and the pilot air discharge flow path 36. The pilot air discharged to the cover air supply port 32 in this manner flows through the cover air flow path 18 as cover air.

[0030] As described above, in this embodiment, the exhaust pilot air is used as cover air. The exhaust pilot air does not excessively cool the condensation prevention cover 16 because the temperature drop is relatively small and the flow rate is small, so it can be suitably used as cover air. Furthermore, because the pilot air is part of the compressed air, it has a low dew point temperature and does not cause condensation on the surface of the main valve housing 14. The valve unit 10A of this embodiment can prevent condensation from occurring. Furthermore, because the valve unit 10A of this embodiment uses the exhaust pilot air, the compressed air can be used without waste.

[0031] In the illustrated example, the pilot valve 40 is disposed outside the condensation prevention cover 16, but this embodiment is not limited to this. The pilot valve 40 may be connected to the main valve housing 14, or the pilot valve 40 may be disposed inside the condensation prevention cover 16 together with the main valve housing 14.

[0032] The valve unit 10A of this embodiment is not limited to the above example. For example, the main valve 12A may include a pilot piston 42b instead of the return member 42a. In this case, the main valve 12A is displaced from the first position to the second position and from the second position to the first position by the two pilot pistons 42b. In this embodiment, the pilot air exhaust from both of the two pilot pistons 42b may be used as cover air, or only one of the pilot air exhausts may be used as cover air.

[0033] (Third embodiment) As shown in Fig. 3, the booster valve 50 of this embodiment boosts the pressure of compressed air that flows in through an inlet port 52 and outputs the compressed air from an output port 54. In Figs. 3 and 4, the same components as those in Fig. 1 or 2 are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. The booster valve 50 of this embodiment is connected to, for example, an air supply line in a factory, and supplies boosted compressed air to locations where local pressure boosting is required.

[0034] The booster valve 50 of this embodiment has a first booster cylinder 56, a second booster cylinder 58, a partition wall 60, and a valve unit 10B. The first booster cylinder 56 and the second booster cylinder 58 are connected via the partition wall 60. The valve unit 10B is attached to the upper part of the partition wall 60. The valve unit 10B supplies and exhausts compressed air to and from the first booster cylinder 56 and the second booster cylinder 58.

[0035] 4, the first booster cylinder 56 has a first chamber 62 and a first piston 64. The first chamber 62 is a chamber (cylinder chamber) extending in the axial direction, and is partitioned by the first piston 64 into a first working chamber 62a and a first booster chamber 62b. The first working chamber 62a is located farther from the partition wall 60 than the first booster chamber 62b. The first piston 64 slides inside the first chamber 62 in the axial direction.

[0036] The second booster cylinder 58 has a second chamber 66 and a second piston 68. The second chamber 66 is a chamber (cylinder chamber) that extends in the axial direction and is coaxial with the first chamber 62, and is partitioned by the second piston 68 into a second working chamber 66a and a second booster chamber 66b. The second working chamber 66a is located farther from the partition wall 60 than the second booster chamber 66b. The second piston 68 slides axially inside the second chamber 66.

[0037] The first pressure boosting chamber 62b and the second pressure boosting chamber 66b are connected to the inlet port 52 via a check valve (not shown) that allows compressed air to pass only in the inflow direction, and the first pressure boosting chamber 62b and the second pressure boosting chamber 66b are connected to the output port 54 via a check valve (not shown) that allows compressed air with increased pressure to pass only in the outflow direction.

[0038] The pressure increase valve 50 has a piston rod 70 that connects the first piston 64 and the second piston 68. The piston rod 70 extends axially, penetrating the partition wall 60. The piston rod 70 is inserted through an insertion hole 60a of the partition wall 60 so as to be displaceable in the axial direction. The first piston 64, the second piston 68, and the piston rod 70 displace integrally in the axial direction.

[0039] The partition wall 60 is provided with a first pilot valve 72 and a second pilot valve 74. The first pilot valve 72 has a first pin 72a that protrudes from the partition wall 60 toward the first pressure increase chamber 62b. When the first piston 64 displaces to the right in the figure, the first pin 72a is pushed by the first piston 64, switching the position of the first pilot valve 72. The second pilot valve 74 has a second pin 74a that protrudes from the partition wall 60 toward the second pressure increase chamber 66b. When the second piston 68 displaces to the left in the figure, the second pin 74a is pushed by the second piston 68, switching the position of the second pilot valve 74.

[0040] The operation of the valve unit 10B is controlled by a first pilot valve 72 and a second pilot valve 74. When the first pin 72a of the first pilot valve 72 is pressed by the first piston 64, the valve unit 10B connects the first working chamber 62a to the exhaust port 14a and connects the second working chamber 66a to the introduction port 52. When the second pin 74a of the second pilot valve 74 is pressed by the second piston 68, the valve unit 10B connects the first working chamber 62a to the introduction port 52 and connects the second working chamber 66a to the exhaust port 14a.

[0041] 3 and 4, the valve unit 10B has a main valve housing 14B that houses a main valve 12B, a flow path member 15, and a condensation prevention cover 16B that covers the outside of the main valve housing 14B. The main valve 12B of the valve unit 10B is connected to an inlet port 52, an exhaust port 14a, a first working chamber 62a, and a second working chamber 66a. The valve unit 10B is switched by pilot air supplied from at least one of a first pilot valve 72 and a second pilot valve 74.

[0042] Specifically, when the first pilot valve 72 is pressed by the first piston 64, pilot air is supplied to the second pilot valve 74, and the second pilot valve 74 returns to the state it was in before being pressed. Also, when the second pilot valve 74 is pressed by the second piston 68, pilot air is supplied to the first pilot valve 72, and the first pilot valve 72 returns to the state it was in before being pressed. The output of the pilot signal to the valve unit 10B switches every time either the first pilot valve 72 or the second pilot valve 74 is pressed.

[0043] The main valve housing 14B is fixed to the upper part of the partition wall portion 60 via a flow path member 15. The main valve housing 14B is supported from the sides by the flow path member 15, and at least the lower surface of the main valve housing 14B is separated from the flow path member 15. Pilot air flows from the lower surface of the main valve housing 14B around to the sides and flows through a cover air flow path 18 so as to cover the periphery of the main valve housing 14B. This structure prevents the cold heat of the main valve housing 14B from being transferred to surrounding structures and prevents the occurrence of condensation. The flow path member 15 has multiple flow paths therein for supplying and discharging pilot air and compressed air.

[0044] A cover air supply port 32B that discharges pilot air is provided in the partition wall portion 60. The cover air supply port 32B is located adjacent to the gap 15a between the underside of the flow path member 15 and the partition wall portion 60, and blows exhaust pilot air onto the underside of the flow path member 15. The cover air that flows out from the cover air supply port 32B is guided through the gap 15a to the cover air flow path 18 of the condensation prevention cover 16B. Note that the position of the cover air supply port 32B is not limited to the above example. The cover air supply port 32B may be provided on the underside of the flow path member 15 or the underside of the main valve housing 14B.

[0045] The condensation prevention cover 16B is formed in a box shape and covers four side surfaces and one upper surface of the main valve housing 14B and the flow path member 15. A cover air flow path 18 for circulating cover air is formed between the condensation prevention cover 16B and the main valve housing 14B. A through hole 78 is formed at the upper end of the condensation prevention cover 16B. The through hole 78 communicates with the exhaust port 14a provided at the upper end of the main valve housing 14B. The condensation prevention cover 16B tightly contacts the condensation prevention cover 16B around the exhaust port 14a, thereby preventing the compressed air discharged from the exhaust port 14a from flowing into the cover air flow path 18.

[0046] In addition, a sound deadening material 100 made of a porous sheet material is disposed between the exhaust port 14a and the through-holes 78. The sound deadening material 100 suppresses the exhaust noise of the exhaust air passing through the exhaust port 14a and the through-holes 78. The exhaust air that passes through the sound deadening material 100 is discharged through the through-holes 78 of the condensation prevention cover 16B without entering the cover air flow path 18.

[0047] A cover air exhaust port 34 is provided at a predetermined position on the side of the dew condensation prevention cover 16B. The cover air is exhausted to the outside through the cover air exhaust port 34.

[0048] The booster valve 50 of this embodiment is configured as described above. The booster valve 50 alternately performs a first stroke and a second stroke through the operation of the valve unit 10B. The first stroke is an operation in which compressed air is discharged from the first working chamber 62a while compressed air is supplied to the second working chamber 66a. The second stroke is an operation in which compressed air is supplied to the first working chamber 62a and compressed air is discharged from the second working chamber 66a. In the first stroke, the compressed air in the second booster chamber 66b is boosted, and in the second stroke, the compressed air in the first booster chamber 62b is boosted.

[0049] The valve unit 10B exhausts compressed air from the first working chamber 62a during the first stroke, and exhausts compressed air from the second working chamber 66a during the second stroke. Therefore, the valve unit 10B used in the booster valve 50 is prone to temperature drops due to adiabatic expansion caused by the exhaust of compressed air. The valve unit 10B may repeatedly exhaust air at high frequency, which can exacerbate the effects of temperature drops depending on the operating conditions.

[0050] In the pressure increase valve 50 of this embodiment, the outside of the main valve housing 14B of the valve unit 10B is covered with a condensation prevention cover 16B, and further, exhausted pilot air is circulated as cover air between the main valve housing 14B and the condensation prevention cover 16B. This allows the pressure increase valve 50 to effectively suppress the occurrence of condensation in the valve unit 10B.

[0051] (Fourth embodiment) As shown in Figures 5 and 6, this embodiment relates to a pressure increase valve 50A according to another design example. In Figures 5 and 6, the same components as those in Figures 1 and 2 are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. The pressure increase valve 50A of this embodiment includes a first actuating cylinder 82, a second actuating cylinder 84, a third actuating cylinder 86, a valve unit 10C, and a valve unit 10D. In this pressure increase valve 50A, the third actuating cylinder 86 is disposed between the first actuating cylinder 82 and the second actuating cylinder 84.

[0052] The first actuating cylinder 82 and the third booster cylinder 86 are connected via a first partition wall portion 85. The second actuating cylinder 84 and the third booster cylinder 86 are connected via a second partition wall portion 87. A first pilot valve 85a is provided in the first partition wall portion 85. A second pilot valve 87a is provided in the second partition wall portion 87.

[0053] A first actuating piston 88 is disposed inside the first actuating cylinder 82, a second actuating piston 90 is disposed inside the second actuating cylinder 84, and a booster piston 92 is disposed inside the third booster cylinder 86. The first actuating piston 88, the second actuating piston 90, and the booster piston 92 are connected to one another by a piston rod 94. The booster piston 92 is driven by the first actuating piston 88 and the second actuating piston 90. An inlet port 52 into which compressed air is introduced and an output port 54 from which the boosted compressed air is output are formed on the side of the third booster cylinder 86. Compressed air is introduced into the third booster cylinder 86 from the inlet port 52, and the booster piston 92 is driven to boost the pressure of the compressed air. The compressed air boosted by the third booster cylinder 86 is output from the output port 54.

[0054] The valve unit 10C supplies and exhausts compressed air to the first actuating cylinder 82. The valve unit 10C is switched by pilot air supplied from the second pilot valve 87a. The compressed air supplied by the valve unit 10C moves the first actuating piston 88 in the axial direction, pressing the first pilot valve 85a and causing pilot air to be output from the first pilot valve 85a. The pilot air output from the first pilot valve 85a is supplied to the valve unit 10D, causing the valve unit 10D to switch. In addition, the pilot air output from the first pilot valve 85a returns the second pilot valve 87a to its state before being pressed, and the pilot air from the second pilot valve 87a is shut off. As a result, the valve unit 10C switches.

[0055] The valve unit 10D supplies and exhausts compressed air to the second actuating cylinder 84. The valve unit 10D is switched by pilot air supplied from the first pilot valve 85a. The second actuating piston 90 is displaced by the compressed air supplied from the valve unit 10D. When the second actuating piston 90 is displaced near the stroke end, the second actuating piston 90 presses the second pilot valve 87a. As a result, pilot air is output from the second pilot valve 87a. The pilot air output from the second pilot valve 87a switches the valve unit 10C and at the same time returns the first pilot valve 85a to its state before being pressed. As a result, the pilot air to the first pilot valve 85a is shut off, and the valve unit 10D is switched.

[0056] The valve unit 10C has a main valve housing 14C and a condensation prevention cover 16C. The main valve housing 14C is connected to a first partition wall portion 85 via a first flow path member 96 (flow path member). The main valve housing 14C is supported from one side surface by the first flow path member 96. The lower surface of the main valve housing 14C is spaced apart from the first actuation cylinder 82. The first partition wall portion 85 has a cover air supply port 32C that supplies exhausted pilot air as cover air. A slit 96a of the first flow path member 96 is formed above the cover air supply port 32C. The exhaust air discharged from the cover air supply port 32C is supplied to the gap between the lower surface of the main valve housing 14C and the first actuation cylinder 82 through the slit 96a.

[0057] The condensation prevention cover 16C is box-shaped and covers the bottom, three side surfaces, and top surface of the main valve housing 14C. The condensation prevention cover 16C forms a cover air flow path 18 that allows cover air to circulate between the condensation prevention cover 16C and the main valve housing 14C. The side walls and top wall of the condensation prevention cover 16C extend to a position where they overlap with the first flow path member 96. A gap is formed between the condensation prevention cover 16C and the first flow path member 96, and this gap constitutes the cover air exhaust port 34 through which the cover air is discharged. The condensation prevention cover 16C has a through-hole 78 at its upper end that communicates with the exhaust port 14a of the main valve housing 14C. The condensation prevention cover 16C is in close contact with the main valve housing 14C around the exhaust port 14a. This prevents exhaust air from flowing into the cover air flow path 18. A sound-deadening material 100 made of a porous sheet is disposed in the area where the condensation prevention cover 16C and the main valve housing 14C are in close contact. The sound deadening material 100 suppresses the exhaust noise of the exhaust air.

[0058] Valve unit 10D has a main valve housing 14D and a condensation prevention cover 16D. Valve unit 10D is provided symmetrically to valve unit 10C and has the same basic configuration as valve unit 10C. In the configuration of valve unit 10D, components that are common to corresponding components of valve unit 10C are designated by the same reference numerals with a suffix D, and detailed descriptions thereof will be omitted.

[0059] The main valve housing 14D of the valve unit 10D is connected to the second partition wall portion 87 via a second flow path member 98 (flow path member). The second partition wall portion 87 has a cover air supply port 32D that discharges exhausted pilot air. A slit 98a is formed above the cover air supply port 32D by cutting out a portion of the lower end portion of the second flow path member 98. The slit 98a forms a path through which the exhausted pilot air can flow, and guides the exhausted pilot air to the gap between the lower surface of the main valve housing 14D and the second actuation cylinder 84. In other words, the slit 98a supplies the exhausted pilot air to the lower surface of the main valve housing 14D as cover air.

[0060] The booster valve 50A of this embodiment is configured as described above. In the booster valve 50A, exhausted pilot air is supplied as cover air. In the valve unit 10C, the cover air flows from the bottom surface of the main valve housing 14C, past the side, and then past the top surface, and is discharged from the gap between the condensation prevention cover 16C and the first flow path member 96. This cover air prevents condensation in the valve unit 10C. Similarly, in the valve unit 10D, cover air supplied as exhausted pilot air prevents condensation in the valve unit 10D. In this way, the booster valve 50A of this embodiment prevents condensation in the valve units 10C and 10D.

[0061] The following additional notes are further disclosed regarding the above embodiment.

[0062] (Appendix 1) The valve units 10, 10A, 10B, 10C, and 10D of the present disclosure include main valves 12, 12A, and 12B that alternately connect an exhaust port 14a and a compressed air supply source 22 to compressed air equipment, main valve housings 14, 14B, 14C, and 14D that house the main valves, anti-condensation covers 16, 16B, 16C, and 16D that cover the outside of the main valve housing and form a cover air flow path 18 between them and the main valve housing, and cover air supply ports 32, 32B, 32C, and 32D that communicate with one end of the cover air flow path and supply a portion of the compressed air supplied from the compressed air supply source.

[0063] Compressed air used to drive pneumatic equipment has moisture removed to prevent internal condensation, and generally has a low dew point. Therefore, the valve unit and booster valve of the above-described aspects utilize the low dew point of compressed air. Specifically, the valve unit of the above-described aspects has a condensation prevention cover that covers the periphery of the main valve housing, where a temperature drop occurs. The condensation prevention cover forms a cover air flow path between the cover and the main valve housing. A portion of the compressed air flows through the cover air flow path as cover air. The dew point of typical compressed air is, for example, approximately −14°C to −23°C, making condensation unlikely even when the temperature of the main valve housing drops. Therefore, the valve unit and booster valve of the above-described aspects can prevent condensation from forming on the surface of the valve unit (main valve housing). Furthermore, in one non-limiting aspect, exhaust pilot air is used as cover air to ensure efficient use of compressed air.

[0064] (Appendix 2) In the valve unit described in Appendix 1, the condensation prevention cover may be formed of a material that does not easily conduct heat. The valve unit can prevent condensation from occurring on the surface of the condensation prevention cover by preventing the cold and heat of the main valve housing from being transmitted to the surface of the condensation prevention cover. Examples of materials that do not easily conduct heat include various resins.

[0065] (Appendix 3) The valve unit described in Supplementary Note 2 may include a pilot piston 42b that drives the main valve with pilot air, and the exhaust port of the pilot piston may be connected to the cover air supply port. This valve unit uses the exhaust pilot air as part of the compressed air, thereby making it possible to use the compressed air without waste. The exhaust pilot air has a low dew point temperature, similar to compressed air, and has a flow rate sufficient to prevent condensation on the main valve housing. Furthermore, the exhaust pilot air is not as cold as the exhaust air discharged by the main valve, so it does not cool the condensation prevention cover, and therefore condensation does not form on the condensation prevention cover.

[0066] (Appendix 4) In the valve unit described in Supplementary Note 3, the exhaust port and the cover air supply port may be connected via a pilot valve 40 that supplies and exhausts the pilot air. This valve unit can introduce exhaust of pilot air into the cover air flow path through the pilot valve.

[0067] (Appendix 5) In the valve unit described in any one of Supplementary Notes 1 to 4, the main valve housing may have the exhaust port, and the condensation prevention cover may have a through-hole 78 in a portion facing the exhaust port. This valve unit can prevent exhaust air, which causes adiabatic expansion when exhausted through the main valve, from flowing into the cover air flow path.

[0068] (Appendix 6) In the valve unit described in Supplementary Note 5, the condensation prevention cover may be in close contact with the main valve housing around the exhaust port. This valve unit can prevent discharged compressed air whose temperature has been reduced from entering the cover air flow path, suppressing a decrease in the temperature of the condensation prevention cover and preventing condensation on the surface of the condensation prevention cover.

[0069] (Appendix 7) The valve unit according to Supplementary Note 6 may include a flow path member 15 incorporating a flow path connected to the main valve, the main valve housing being supported by the flow path member, and the cover air flow path being formed to cover the outside of the main valve housing. This valve unit can cover almost the entire area of ​​the main valve housing except for the support portion with cover air, preventing cooling of peripheral devices and effectively preventing condensation.

[0070] (Appendix 8) In the valve unit described in Supplementary Note 7, the condensation prevention cover may have a cover air exhaust port 34 for exhausting cover air on the upper side of the main valve housing, and the cover air supply port may be located on the lower side of the main valve housing. This valve unit allows the cover air to flow smoothly around the main valve housing without stagnating, thereby preventing the occurrence of localized low-temperature areas on the condensation prevention cover.

[0071] (Appendix 9) In the valve unit described in Supplementary Note 8, a sound-deadening material 100 may be disposed between the exhaust port and the through-hole of the condensation prevention cover. This valve unit can reduce exhaust noise.

[0072] (Appendix 10) The booster valves 50, 50A of the present disclosure include the valve unit described in any one of Supplementary Notes 1 to 9. This booster valve can prevent condensation in the valve unit at low cost without reducing performance and efficiency.

[0073] (Appendix 11) The booster valve according to Supplementary Note 10 includes a cylinder chamber incorporating a booster piston 92, and a flow path member (96, 98) incorporating a flow path connecting the main valve of the valve unit and the cylinder chamber, wherein the valve unit is connected to the cylinder chamber from a side via the flow path member, and a lower surface of the valve unit may be spaced apart from the cylinder chamber. This booster valve can prevent cooling of the cylinder chamber through the valve unit, and can prevent condensation from occurring in the cylinder chamber.

[0074] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0075] 10, 10A, 10B, 10C, 10D... Valve unit 12, 12A, 12B…Main valve 14, 14B, 14C, 14D...Main valve housing 14a...exhaust port 15...flow path member 16, 16B, 16C, 16D...Condensation prevention cover 18...Cover air passage 22...Compressed air supply source 24...Exhaust port 32, 32B, 32C, 32D...Cover air supply port 34...Cover air exhaust port 40...Pilot valve 42b...Pilot piston 50, 50A...Booster valve 78...Through hole 100...Sound deadening material

Claims

1. a main valve for alternately connecting an exhaust port and a compressed air supply source to the compressed air equipment; a main valve housing that accommodates the main valve; a dew condensation prevention cover that covers the outside of the main valve housing and forms a cover air flow path between the main valve housing and the cover air flow path; a cover air supply port that communicates with one end of the cover air flow path and supplies a portion of the compressed air supplied from the compressed air supply source.

2. 2. The valve unit according to claim 1, wherein the condensation prevention cover is made of a material that does not easily transmit heat.

3. The valve unit according to claim 2, a pilot piston that drives the main valve with pilot air; a valve unit in which the exhaust port of the pilot piston and the cover air supply port are in communication with each other;

4. The valve unit according to claim 3, a valve unit in which the exhaust port and the cover air supply port are connected via a pilot valve that supplies and exhausts the pilot air.

5. The valve unit according to claim 1, the main valve housing has the exhaust port, The condensation prevention cover has a through hole in a portion facing the exhaust port.

6. 6. The valve unit according to claim 5, wherein the condensation prevention cover is in close contact with the main valve housing around the exhaust port.

7. 7. The valve unit according to claim 6, a flow path member incorporating a flow path connected to the main valve; The main valve housing is supported by the flow path member, and the cover air flow path is formed to cover the outside of the main valve housing.

8. 8. A valve unit according to claim 7, wherein the condensation prevention cover has a cover air exhaust port on the upper side of the main valve housing for exhausting cover air, and the cover air supply port is located on the lower side of the main valve housing.

9. 9. The valve unit according to claim 8, wherein a sound-deadening material is disposed between the exhaust port and the through-hole of the condensation prevention cover.

10. A pressure booster valve comprising the valve unit according to any one of claims 1 to 9.

11. 11. The pressure increase valve according to claim 10, a cylinder chamber incorporating a booster piston; a flow path member incorporating a flow path connecting the main valve of the valve unit and the cylinder chamber, the valve unit is connected to the cylinder chamber from a side via the flow path member, A pressure booster valve, wherein a lower surface of the valve unit is spaced apart from the cylinder chamber.

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