JP2019190599A - Follow-up pressure valve - Google Patents

Abstract

To provide a follow-up pressure valve showing superior workability as well as a safety characteristic without any springing-out of component parts by an energization force of a spring.SOLUTION: Within a spring chamber 50 is provided an end plate 55 having a size not enabling to pass through a communication hole 54, a spring 40 is stored between an inner surface of the other end side end wall 53 and the end plate 55, the other end 30b of a valve rod 30 having a valve body 20 fixed to one end 30a is abutted against or connected to said end plate 55 through the communication hole 54 arranged at one end side end wall 52 of the spring chamber 50 and an attachment hole 16 arranged at the valve case 10, thereby a valve body 20 can be sat at a sheet surface 11a arranged at a communication port 11 of a valve case 10. When the valve body 20 is sat at the sheet surface 11a to close the valve, the end plate 55 is contacted with an inner surface of one end side end wall 52 and arranged at a position where it is approached through a minimum clearance δ, thereby even if the fastening between the valve case 10 and the spring chamber 50 is released, elongation of the spring 40 is restricted to prevent a springing-out of the spring chamber 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure-holding valve, for example, in an oil-cooled screw compressor, such as a pressure-holding valve provided between a receiver tank and a consumer side in order to keep the pressure in the receiver tank at a predetermined set pressure or higher. This is related to the structure of a pressure holding valve that opens when the fluid pressure on the side exceeds a predetermined set pressure and closes when the fluid pressure is below the set pressure.

  In the oil-cooled screw compressor 100 shown in FIG. 7, the compressor main body 130 compresses a compressed gas such as air introduced through the suction passage 137 together with the cooling oil by the meshing rotation of the pair of screw rotors. Since it is configured to discharge as a gas-liquid mixed fluid, the compressed gas discharged as a gas-liquid mixed fluid from the compressor body 130 is once introduced into the receiver tank 160 and separated into compressed gas and cooling oil. To be done.

  The compressed gas introduced into the receiver tank 160 and from which the cooling oil is separated is further passed through the separator 165 to remove oil contained in the compressed gas in the form of mist, and then supplied to the consumer side.

  In the oil-cooled screw compressor 100 configured as described above, if the flow rate of the compressed gas passing through the separator 165 is too high, the separator 165 cannot sufficiently collect the cooling oil, and the consumption side Since compressed gas containing oil may be supplied, it is necessary to limit the flow rate of the compressed gas passing through the separator 165.

  Further, since the lubricating oil collected in the receiver tank 160 is supplied to the oil supply port of the compressor main body 130 via the oil supply passage 140 by the pressure in the receiver tank 160, the pressure in the receiver tank 160 is It is necessary to maintain the pressure required for such refueling.

  Therefore, a pressure holding valve 200 is provided on the secondary side of the separator 165 to restrict the flow rate of the compressed gas passing through the separator 165 to prevent the oil separation performance of the separator 165 from deteriorating, and the pressure in the receiver tank 160 is reduced. By preventing the pressure from dropping below a predetermined set pressure and maintaining the pressure required to supply cooling oil to the compressor body 130, damage to the compressor body 130 due to poor lubrication can be prevented. Yes.

  As the pressure-holding valve 200 provided in such an oil-cooled screw compressor 100, Patent Document 1 and Patent Document 2 described below describe the pressure-holding valve 200 shown in FIGS.

  These holding valves 200 are provided with a valve box 210 as a main body, an inlet 212 communicating with the separator 165 of the receiver tank 160, and an outlet 213 communicating with the consumption side. , A primary flow path 214 communicating with the inlet 212 and a secondary flow path 215 communicating with the outlet 213 are formed, and the primary flow path 214 and the secondary flow path 215 communicate with each other. The communication port 211 can be opened and closed by seating or separating the valve body 220 on the seat surface 211a.

  The valve body 220 has a valve shaft 222 slidably inserted into the insertion hole 231 and is attached to one end of the piston 230. The piston 230 and the piston 230 are attached to the communication port 211. A cylinder 260 that accommodates the spring 240 to be energized has a structure protruding above the valve box 210.

  In the pressure holding valve 200 configured as described above, when the pressure in the receiver tank 160 exceeds a predetermined pressure (set pressure) determined by the urging force of the spring 240, the urging force of the spring 240 is resisted. The valve body 220 moves away from the seat surface 211a to open the communication port 211, and the compressed gas is supplied to the consumption side. On the other hand, when the pressure in the receiver tank 160 falls below the set pressure, the urging force of the spring 240 causes the valve body 220 to be seated on the seat surface 211a provided in the communication port 211, thereby closing the communication port 211 and consuming it. Supply of compressed gas to the side stops. As a result, the pressure in the receiver tank 160 does not drop below the set pressure, but can be maintained at a pressure higher than the set pressure.

JP 2016-44787 A Japanese Utility Model Publication No. 57-137869

  In the pressure-holding valve 200 configured as described above, a sealing material such as an O-ring is provided between the outer periphery of the piston 230 and the inner wall of the cylinder 260 as shown in FIG. 234 is provided.

  In order to prevent leakage when the valve is closed, the valve body 220 itself or a portion that contacts the seat surface 211a of the valve body 220 is formed of an elastic material such as rubber, and the seat surface 211a of the communication port 211 is formed on the seat surface 211a. A sealing material is attached.

  Therefore, such a pressure-holding valve 200 requires maintenance work such as periodically replacing the sealing material and the valve body described above. In order to perform this maintenance work, a part of the pressure-holding valve 200 is removed, and the valve The upper part of the box 210 is opened.

  In the pressure-holding valve 200 described in Patent Document 1 shown in FIG. 8, when the fixing ring 259 that fixes the cylinder 260 to the valve box 210 is removed by removing a fastening member such as a bolt (not shown), the lower end of the cylinder 260 is removed. Can be extracted from the valve box 210, whereby the upper portion of the valve box 210 can be opened, and the above-described sealing material and valve body 220 can be replaced.

  However, since the above-described spring 240 is accommodated in the cylinder 260 in a compressed state so that the valve body 220 can be urged toward the communication port 211 via the piston 230, the fixing ring 259 If the cylinder is removed, the cylinder 260 and the spring 240 may be ejected vigorously by the urging force of the spring 240, and these parts may be lost, and if the ejected parts hit the operator, there is a risk of injury.

  Therefore, when removing the cylinder 260, in order to prevent such jumping out, a bolt or the like that holds the fixing ring 259 and the valve box 210 with the other hand while holding the upper side of the cylinder 260 with one hand. Since it is necessary to work to loosen the fastening member, workability is poor.

  In particular, when the set pressure of the pressure-holding valve 200 is high, the biasing force of the spring 240 is also increased accordingly, so that the force that causes the cylinder 260 to jump out is large, and the cylinder 260 is pressed down with a strong force that overcomes this force. The removal / removal operation of the cylinder 260 performed further deteriorates the workability, and since the force that causes the cylinder 260 to jump out is large, the injury caused to the worker by hitting the cylinder 260 and the spring 240 that jumps out is also serious. It can be a nasty thing.

  As a method for preventing such a cylinder 260 from popping out, for example, a fastening member such as a bolt (not shown) that fastens the fixing ring 259 and the valve box 210 is made long, and a plurality of fastening members are used. By gradually loosening it in several steps in order, the spring 240 is extended to the free length until the fastening member has been loosened, or the cylinder 260 is extended to a length where the urging force is sufficiently weakened. It is also conceivable that the removal work can be performed without holding down.

  In this method, it is not necessary to hold down the cylinder 260, and the workability is improved in that the fastening member such as a bolt can be removed using both hands. Since the number of times the fastening member is turned increases, the workability is still not improved.

  In the structure of the pressure holding valve 200 described in Patent Document 2 shown in FIG. 9, the valve box 210 and the cylinder 260 are integrally formed, and the upper end of the cylinder 260 is closed by the top cover 253. Since the adjustment screw 253c for adjusting the urging force of the spring 240 is provided on the top lid 253, the adjustment screw 253c is loosened before removing the top lid 253, and the spring 240 is extended to a free length or a state close thereto. By removing the top cover 253 with the biasing force lost or sufficiently weakened, it is possible to prevent the top cover 253, the receiving plate 255 ′, and the spring 240 from jumping out without holding the top cover 253 by hand. .

  However, when the set pressure of the pressure-holding valve 200 is high, the spring 240 can be prevented from popping out the top lid 253, the tray 255 ′, and the spring 240 only by loosening the adjusting screw 253 c with a force held by one hand. In some cases, the urging force cannot be weakened, and structurally poor workability at the time of disassembly and work danger still exist.

  In the configuration of the pressure-holding valve 200 described in Patent Document 2 shown in FIG. 9, the length of the cylinder 260 is lengthened and the length of the adjusting screw 253c is lengthened to adjust the pressure before removing the top cover 253. If the spring 240 can be extended to a free length by loosening the screw 253c, it is possible to prevent the top lid 253, the receiving plate 255 ′, and the spring 240 from popping out without being pressed by hand even with the holding valve 200 having a high set pressure. However, even in this configuration, since the adjustment screw 253c becomes longer, the number of times of turning the adjustment screw 253c before disassembly and the number of times of turning the adjustment screw 253c to return to the set pressure after assembly increase, so that workability is poor. The problem that the pressure holding valve 200 becomes larger due to the longer cylinder 260 occurs.

  In the above description, the pressure holding valve used in the oil-cooled screw compressor has been described as an example. However, when disassembling, the component parts pop out due to the urging force of the built-in spring, and the resulting poor workability. The danger is a problem that can occur not only in the holding valve used in oil-cooled screw compressors, but also in the entire holding valve, and not only in holding valves for gases but also in liquids and other fluids in general. This is a problem that may occur in common for all pressure holding valves to be controlled.

  Therefore, the present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and although it has a relatively simple structure, the components of the pressure-holding valve do not pop out during disassembly due to the biasing force of the built-in spring. Accordingly, an object of the present invention is to provide a pressure retaining valve having a structure capable of improving workability at the time of disassembling for opening the valve box of the pressure retaining valve and removing the risk of work associated with part jumping. To do.

  Hereinafter, means for solving the problem will be described together with reference numerals used in the embodiment for carrying out the invention. This code is used to clarify the correspondence between the description of the claims and the description of the mode for carrying out the invention. Needless to say, it is used in a limited manner to interpret the technical scope of the present invention. Is not something

In order to achieve the above object, the pressure-holding valve 1 of the present invention includes:
A valve box 10 having a primary flow path 14 communicating with the inlet 12, a secondary flow path 15 communicating with the outlet 13, and a communication port 11 communicating the primary flow path 14 and the secondary flow path 15;
A valve body 20 for opening and closing the communication port 11;
A valve stem 30 to which the valve body 20 is attached to one end 30a;
A spring 40 that presses the other end 30b of the valve stem 30 and urges the valve body 20 in a direction to be seated on a seat surface 11a provided in the communication port 11;
A communication hole 54 provided in one end side end wall 52 that defines one end 50 a of the spring chamber 50 that accommodates the spring 40 communicates with the secondary flow path 15 via the mounting hole 16 provided in the valve box 10. As described above, the one end 50a of the spring chamber 50 is detachably attached to the valve box 10,
The spring chamber 50 includes an end plate 55 of a size that can move in the spring chamber 50 and cannot pass through the communication hole 54. The spring chamber 50 includes an inner surface of the other end wall 53 of the spring chamber 50, and the end plate 55. The spring 40 is accommodated between the plates 55,
The other end 30b of the valve stem 30 is in contact with or connected to the end plate 55 through the mounting hole 16 and the communication hole 54,
When the end plate 55 is in contact with the inner surface of the one end side end wall 52, or close to the end plate 55 with a minute interval δ, the communication port 11 is closed by the valve body 20 and closed. It is characterized by comprising (claim 1).

  In the pressure-holding valve 1 configured as described above, the end plate 55 and the valve stem 30 can be formed as separate members (Claim 2; see FIGS. 1 to 5).

  Alternatively, the end plate 55 and the valve stem 30 may be integrally formed and connected (Claim 3; see FIG. 6).

  Further, a second end plate 55 ′ movable within the spring chamber 50 is provided between the inner wall of the other end side end wall 53 of the spring chamber 50 and the spring 40, and the end plate 55 and the second plate The spring 40 is held between the end plates 55 ′ and screw holes 53 b that penetrate the other end side end wall 53 of the spring chamber 50 are screwed into the spring chamber 50 from the outside of the spring chamber 50. Further, a set pressure adjusting bolt 53c whose tip is in contact with the second end plate 55 ′ may be provided (see claim 4; see FIG. 4).

  The one end 50 a of the spring chamber 50 is provided with a cylinder 60 that communicates with the communication hole 54 and protrudes into the secondary flow path 15, and slides the valve rod 30 in the cylinder 60 in the axial direction. It can also be formed in a piston-like structure (see claim 5; see FIGS. 1 to 5).

  Alternatively, instead of the above configuration, the mounting hole 16 provided in the valve box 10 is formed as a cylinder 60 ', and the valve rod 30 is formed in a piston-like structure that slides in the cylinder 60' in the axial direction. (Claim 6; see FIG. 6).

  With the configuration of the present invention described above, the following significant effects can be obtained with the pressure retaining valve 1 of the present invention.

  The spring chamber 50 is arranged such that a communication hole 54 provided at one end 50 a of the spring chamber 50 that accommodates the spring 40 communicates with the secondary flow path 15 of the valve box 10 via the mounting hole 16 provided in the valve box 10. One end 50a is detachably attached to the valve box 10, and an end plate 55 is provided in the spring chamber 50. The end plate 55 has a size that can move in the spring chamber 50 and cannot pass through the communication hole 54. The spring 40 is accommodated between the inner surface of the end wall 53 on the other end side of the chamber 50 and the end plate 55, and is attached to the end plate 55 through the mounting hole 16 and the communication hole 54 to the end plate 55. The other end 30b of the valve rod 30 that transmits the urging force of the spring 40 is brought into contact with or connected to the valve body 20, and the position where the end plate 55 is in contact with the inner surface of the end wall 52 on the one end side, or a minute interval. δ The communication port 11 is closed by the valve body 20 when it is close to the valve body 20 so as to close the valve, so that a bolt or the like that fixes one end 50a of the spring chamber 50 to the valve box 10 can be used. Even when the fastening member is removed, the spring 40 does not extend, or can only extend a length corresponding to the minute interval δ, and therefore is accommodated in the spring chamber 50 or the spring chamber 50. A structure in which parts such as the spring 40 and the end plate 55 do not pop out can be obtained.

  As a result, when removing the spring chamber 50 when replacing the seal member 34, the valve body 20, etc., it is not necessary to hold the spring chamber 50 so that it does not jump out, and the workability during disassembly can be improved. Thus, it was possible to provide a pressure-retaining valve 1 that has no danger of causing injury due to the protruding parts hitting an operator and that is excellent in safety during disassembling work.

The exploded sectional view showing one embodiment of the pressure-holding valve of the present invention. Sectional drawing which shows one Embodiment of the pressure-holding valve of this invention (valve closed state). Sectional drawing (valve open state) which shows one Embodiment of the pressure-holding valve of this invention. Sectional drawing which shows the modification of the pressure-holding valve of this invention. Sectional drawing which shows another modification of the pressure-holding valve of this invention. Sectional drawing which shows another modification of the pressure-holding valve of this invention. Explanatory drawing which shows the whole structure of an oil-cooled screw compressor. Sectional drawing of the conventional holding | maintenance valve (corresponding to the holding | maintenance valve of patent document 1). Sectional drawing of the conventional pressure holding valve (corresponding to the pressure holding valve of Patent Document 2).

  The pressure holding valve of the present invention will be described below with reference to the accompanying drawings.

1. Embodiment 1
[Overall configuration of pressure holding valve]
Referring to FIG. 1, the structure of a pressure holding valve 1 according to an embodiment of the present invention will be described. The pressure holding valve 1 includes a valve box 10 constituting a main body of the pressure holding valve 1 and a primary formed in the valve box 10. A valve body 20 that opens and closes the communication port 11 communicating between the flow path 14 and the secondary flow path 15, a valve rod 30 to which the valve body 20 is attached to one end 30a, and the other end 30b of the valve rod 30; The valve body 20 includes a spring 40 that urges the valve body 20 toward the communication port 11 and a spring chamber 50 that houses the spring 40.

(Valve box)
The above-described valve box 10 constitutes a main body portion of the pressure-holding valve 1, and the valve box 10 includes a pressure-holding target such as the receiver tank 160 of the oil-cooled screw compressor 100 described with reference to FIG. An inlet 12 communicated with the device to be operated, an outlet 13 for discharging the fluid introduced through the inlet 12, a primary flow path 14 communicating with the inlet 12, and a communication with the outlet 13 are provided. A secondary flow path 15 is provided therein, and the primary flow path 14 and the secondary flow path 15 are communicated with each other via the communication port 11.

  Therefore, the valve body 20 (described later) is seated on the seat surface 11a provided at the communication port 11 to block communication between the primary flow path 14 and the secondary flow path 15 from the receiver tank 160 to the consumption side. It is comprised so that supply of the compressed gas with respect to can be stopped.

  The communication port 11 is formed with the seat surface 11a for seating the valve body 20 so that the communication port 11 can be closed by the valve body 20 from the secondary flow path 15 side. It is good also as what is comprised so that the sealing material which is not shown in figure may be attached to the part of the said seat surface 11a which contacts the valve body 20 mentioned later among the opening | mouths 11. FIG.

  A mounting hole 16 is provided above the communication port 11 so that a spring chamber 50, which will be described later, can be mounted. One end 50a of the spring chamber 50 is attached to a position where the mounting hole 16 is formed, and the mounting hole 16 is formed. By closing, the flow paths 14 and 15 formed in the valve box 10 can be sealed.

[Spring room]
As described above, one end 50 a of the spring chamber 50 is detachably mounted on the mounting hole 16 provided in the valve box 10. By attaching the spring chamber 50 to the valve box 10, the flow path 14 in the valve box 10 is provided. , 15 can be sealed.

  The spring chamber 50 includes a cylindrical main body 51, one end side end wall 52 that covers one end side of the main body 51, and the other end side end wall (spring chamber cover) 53 that covers the other end side. The aforementioned communication hole 54 is formed in the end wall 52 on the one end side.

  In the present embodiment, a cylindrical cylinder 60 that protrudes from one end 50 a of the spring chamber 50 and has an inner peripheral surface that is continuous with the communication hole 54 is formed integrally with the end wall 52 on the one end side. Is attached to the valve box 10 so that the cylinder 60 protrudes into the secondary flow path 15 toward the communication port 11 in the valve box 10.

  In the spring chamber 50, there is provided an end plate 55 that is movable in the spring chamber 50 but cannot pass through the communication hole 54 described above, and the other end wall (spring chamber cover) of the spring chamber 50 is provided. A spring (coil spring) 40 is accommodated between the inner surface of 53 and the end plate 55.

  In the illustrated embodiment, the end plate 55 is formed in a disc shape smaller in diameter than the inner diameter of the main body 51 of the spring chamber 50, so that the end portion of the spring 40 can be suitably held. A protrusion 56 is formed on the surface (the upper surface of the drawing) of 55 holding the spring 40, and the protrusion 56 can be fitted into the inner diameter of the end of the spring 40.

  Further, an engagement recess that fits into an engagement protrusion 32 formed on the other end 30b of the valve rod 30 described later is formed on the surface opposite to the spring holding surface of the end plate 55 (the surface below the sheet). 57 is formed so that the valve rod 30 and the end plate 55 can be coaxially arranged by fitting them together.

  In the illustrated embodiment, the engaging recess 57 is formed as a through-hole penetrating the thickness of the end plate 55. However, the engaging recess 57 may be formed as a bottomed hole. The structure shown in the drawing is not limited as long as it can be engaged with the engaging protrusion 32 formed on the other end 30b of the valve stem 30.

  In the embodiment shown in FIG. 1, an example of forming the surface (paper surface, lower surface) opposite to the spring holding surface of the end plate 55 into a flat shape excluding the portion where the engagement recess 57 is formed. As shown in FIG. 5, instead of this configuration, the end plate 55 is provided with a protrusion 58 inserted into the communication hole 54 on the surface opposite to the spring holding surface of the end plate 55. May be configured so as to be surely disposed at the center in the radial direction of the spring chamber 50, and this configuration facilitates positioning of the end plate 55 during assembly.

  Similarly, a protrusion 53a inserted into the inner diameter of the end of the spring 40 is provided on the inner surface of the spring chamber cover 53 that covers the other end of the spring chamber 50, and is locked in a state where the upper end of the spring 40 is positioned. It is good also as what can be comprised.

  In the embodiment shown in FIG. 1, the configuration in which the upper end of the spring 40 is directly locked to the inner surface of the spring chamber cover 53 is shown, but instead of this configuration, as shown in FIG. A second end plate 55 ′ is provided between the inner surfaces of the sprink chamber cover 53, and the upper end of the spring 40 is locked to the second end plate 55 ′ and screwed into a screw hole 53 b that penetrates the spring chamber cover 53. The set pressure of the pressure retaining valve 1 can be changed by changing the tightening amount of the set pressure adjusting bolt 53c by bringing the upper surface of the second end plate 55 'into contact with the tip of the set pressure adjusting bolt 53c. You may comprise.

[Valve and valve stem]
A valve body 20 seated on the seat surface 11a of the communication port 11 provided in the valve box 10 and closing the communication port 11 includes a main body 21 and a valve shaft 22 attached to the center of the main body 21 as shown in FIG. When the communication port 11 is closed, the peripheral portion of the main body 21 of the valve body 20 comes into contact with the seat surface 11a provided at the communication port 11, and the communication between the primary channel 14 and the secondary channel 15 is blocked. It is configured as follows.

  In the illustrated embodiment, the valve body 20 has a structure having a disk-shaped main body 21, but the shape of the valve body 20 is not limited to the illustrated one, and the valve body 20 used for the pressure-holding valve 1. Various shapes known in the art can be adopted.

  The valve shaft 22 provided on the valve body 20 is slidably inserted into an insertion hole 31 provided on the one end 30 a side of the valve rod 30, so that the valve body 20 is disposed on the one end 30 a side of the valve rod 30. It is attached.

  Further, the end of the valve shaft 22 is formed hollow to form a spring chamber 22a. A spring 33 for backflow prevention is accommodated in the spring chamber 22a and is extremely weak compared to the spring 40 described above. The valve body 22 is urged in a direction to push out the valve shaft 22 from the insertion hole 31 by force, so that the valve body 20 communicates when a reverse flow of fluid from the secondary flow path 15 side to the primary flow path 14 side occurs. The flow path can be closed by immediately contacting the sheet surface 11a of the mouth 11.

  The above-described valve rod 30 that transmits the urging force of the above-described spring 40 to the valve body 20 has the cylinder 60 protruding from the lower end of the spring chamber 50 as described above. It is formed in the shape of a piston that slides.

  The interval between the outer periphery of the valve stem 30 and the inner periphery of the cylinder 60 is sealed by a sealing member 34 such as an O-ring to prevent fluid from flowing into the spring chamber 50 via this interval. Yes.

  In the illustrated embodiment, a seal groove is formed on the outer periphery of the valve stem 30 and a seal material (O-ring) 34 is attached to the seal groove. However, the seal material (O-ring) 34 is provided inside the cylinder 60. A seal groove may be provided around the circumference and attached here.

  The height dimension of the valve body 20 and the valve stem 30 is such that the lower surface of the end plate 55 provided in the spring chamber 50 is closed when the valve body 20 is seated on the seat surface 11a and the communication port 11 is closed. , It is designed so that it is in a position in contact with the inner surface of the end wall 52 on one end side, or preferably it is in a position close to each other with a minute interval δ as shown in an enlarged view in FIG.

  By setting so that the minute interval δ is generated in this way, the valve body 20 can be reliably brought into contact with the seat surface 11a so that the valve body 20 does not float from the seat surface 11a of the communication port 11.

  The minute interval δ is a length that allows the spring 40 to be extended when the fastening member 65 such as a bolt is removed and the fastening of the spring chamber 50 to the valve box 10 is released. The distance can be set as appropriate within a range that can prevent the spring chamber 50 from popping out. As an example, the distance is set to about several millimeters.

[Action etc.]
In the pressure-holding valve 1 described above, when the pressure in the receiver tank communicating with the inlet 12 is low, and therefore the pressure in the primary flow path 14 of the valve box 10 is low, the valve rod is moved by the spring 40 as shown in FIG. 30 and the valve body 20 are pushed down, the valve body 20 is seated on the seat surface 11a of the communication port 11, and the communication between the primary flow path 14 and the secondary flow path 15 is blocked.

  When the pressure in the receiver tank increases from this state and the pressure in the primary flow path 14 of the valve box 10 increases, a force in the direction of lifting the valve body 20 from the seat surface 11a provided at the communication port 11 is generated. Acts in a direction to compress the spring 40 via the valve body 20 and the valve stem 30.

  Then, when the pressure in the primary flow path 14 overcomes the biasing force of the spring 40 and rises up to push up the valve body 20 and the valve rod 30, the valve body 20 is provided in the communication port 11 as shown in FIG. The primary flow path 14 and the secondary flow path 15 communicate with each other at a distance from the seat surface 11 a, and the compressed gas in the receiver tank is introduced to the consumption side via the secondary flow path 15 and the outlet 13.

  On the other hand, when the pressure in the primary flow path 14 decreases and the force that pushes up the valve body 20 and the valve stem 30 upward is weakened, the spring 40 extends to the original length, and the valve stem 30 descends. By connecting the valve body 20 to the seat surface 11a of the communication port 11 in a state where the upper end of 22 is abutted with the upper end of the insertion hole 31, the communication between the primary flow path 14 and the secondary flow path 15 is cut off. As a result, the pressure in the receiver tank is prevented from dropping below the set pressure.

  As a result, once the pressure in the receiver tank rises above a predetermined set pressure determined by the urging force of the spring 40, the pressure in the receiver tank is maintained above the set pressure and kept from dropping below the set pressure. Pressed.

  In the pressure retaining valve 1 configured as described above, the replacement of the sealing material 34 such as an O-ring provided on the valve stem 30 or the replacement of the valve body 20 is performed by removing the spring chamber 50 from the valve box 10 and mounting holes. This is done by opening 16.

  As shown in FIG. 1 as an example, the spring chamber 50 is fixed to the valve box 10 with a flange 59 projecting outward from the lower end of the spring chamber 50 and the peripheral edge of the mounting hole 16 of the valve box 10 with bolts. It is performed by fastening with fastening members 65 such as.

  In this configuration, by removing the fastening member 65, the spring chamber 50 is removed from the valve box 10, and the cylinder 60 protruding from the lower end of the spring chamber 50 is removed from the secondary flow path 15 of the valve box 10, thereby mounting holes. 16 is opened.

  When the spring 65 is loosened when the spring chamber 50 is removed, the spring 40 extends in the spring chamber 50 until the lower surface of the end plate 55 abuts the inner surface of the end wall 52 on the one end side, and a minute interval δ (FIG. 2). And the spring 40 cannot extend any more, while a gap corresponding to the above-mentioned interval δ is formed between the lower surface of the flange 59 and the peripheral upper surface of the mounting hole 16.

  Thus, before and after the fastening member 65 such as a bolt is attached or detached, the spring 40 can extend only a small length corresponding to the minute interval δ, and as a result, measures such as pressing the spring chamber 50 by hand are taken. Even if it is a case where the bolt 65 is loosened and the spring chamber 50 is removed from the valve box without taking, there is no fear of the spring chamber 50 popping out.

  Further, since the extension of the spring 40 is restricted only by extending the length corresponding to the minute interval δ described above, both of them are fastened as fastening members such as bolts for fastening the spring chamber 50 and the valve box 10. By using the fastening member 65 having a length necessary for the attachment, the attachment can be suitably performed. By using the long fastening member, the number of times of turning the fastening member is increased, so that the labor for attachment / detachment is not increased. .

  Thus, in the pressure retaining valve 1 of the present invention, the spring chamber 50 can be easily and safely removed from the valve box 10.

  Then, the valve rod 30 is extracted from the cylinder 60 extracted from the inside of the valve box 10, the O-ring 34 attached to the outer periphery of the valve rod 30 is replaced, and the communication port 11 is provided via the attachment hole 16 as necessary. The sealing material provided on the seat surface 11a and the valve body 20 are exchanged.

  Even when the valve rod 30 is removed from the cylinder 60, since the extension of the spring 40 is restricted, the valve rod 30 does not come off or jump out due to the urging force of the spring 40. The workability is good and the work can be done safely.

  After replacing the O-ring 34, other sealing materials, the valve body 20 and the like in this way, the valve rod 30 is inserted into the cylinder 60 again, and the cylinder 60 protruding from the lower end of the spring chamber 50 is attached to the mounting hole 16. The flange 59 at the lower end of the spring chamber 50 and the peripheral edge portion of the mounting hole 16 of the valve box 10 are fastened and fixed by the fastening member 65 such as the bolt described above. Thus, the assembly of the pressure holding valve 1 is completed.

  When attaching the spring chamber 50 to the valve box 10, it is not necessary to compress the spring 40 in the spring chamber 50, and the cylinder 60 protruding from the lower end of the spring chamber 50 is inserted into the mounting hole 16 provided in the valve box 10. Thus, the spring chamber 50 can be placed on the valve box 10 without applying a force.

  In this state, the spring chamber 50 can be easily attached to the valve box 10 by attaching a fastening member 65 such as a bolt.

  Thus, in the holding valve 1 of the present invention, the holding valve 1 can be easily and safely disassembled and assembled.

2. Embodiment 2
As described above, in the pressure holding valve 1 described with reference to FIGS. 1 to 5, the example in which the end plate 55 that holds the lower end of the spring 40 is configured separately from the valve rod 30 has been described.

  On the other hand, in the pressure-holding valve 1 of this embodiment shown in FIG. 6, the end plate 55 which hold | maintains the lower end of the spring 40 is formed integrally with the valve rod 30, and both are connected.

  In the embodiment described with reference to FIGS. 1 to 5, a cylinder 60 that protrudes from the lower end of the spring chamber 50 into the secondary flow path 15 of the valve box 10 is provided, and a valve that is inserted into the cylinder 60 is provided. Although the configuration for attaching the O-ring 34 to the seal groove formed on the outer periphery of the rod 30 has been described, in the pressure retaining valve 1 of this embodiment shown in FIG. 6, the attachment hole 16 portion provided in the valve box 10 is formed thick. A cylinder 60 'is formed by the inner wall of the mounting hole 16, and the valve rod 30 formed integrally with the end plate 55 as described above is inserted into the cylinder 60'.

  In the configuration of FIG. 6, the pressure retaining valve described with reference to FIGS. 1 to 5 is provided in that a seal groove is provided on the inner peripheral surface of the cylinder 60 ′ and an O-ring 34 is attached to the seal groove. Different from the configuration.

  When replacing the O-ring 34 in the pressure-holding valve 1 shown in FIG. 6 configured as described above, the fastening member 65 such as a bolt for fixing the flange 59 provided at the lower end of the spring chamber 50 to the valve box is removed and the spring is removed. When the chamber 50 is removed from the valve box 10, the valve rod 30 together with the spring chamber 50 is extracted from the cylinder 60 ', and the O-ring 34 attached to the ring groove formed on the inner wall of the cylinder 60' can be replaced.

  Also in the pressure holding valve 1 having the configuration shown in FIG. 6, the spring chamber 50 can be mounted without attaching the spring chamber 50 by hand when the spring chamber 50 is attached and detached, as in the pressure holding valve 1 described with reference to FIGS. Since there is no fear of popping out, maintenance and other work can be performed efficiently and safely.

  In particular, in the pressure-holding valve 1 having the configuration shown in FIG. 6, the end plate 55 and the valve stem 30 are integrated, so that the number of parts is small, and maintenance work is also possible in that the number of work steps during disassembly and assembly is reduced. In addition, since the center of the end plate 55 and the valve stem 30 always coincide, smooth operation is possible.

  In the embodiment shown in FIG. 6, a configuration in which the O-ring 34 is attached to the inner wall side of the cylinder 60 ′ is shown, but instead of this configuration, a seal groove is formed on the outer periphery of the valve stem 30 to seal the O-ring or the like. It is good also as a structure which attaches material.

  In addition, in the configuration of the pressure retaining valve 1 shown in FIG. 6, as shown in FIG. 4, a second end plate 55 ′ that supports the upper end of the spring 40 is provided, and the screw hole 53 b is formed in the spring chamber cover 53. It is good also as what is comprised so that setting pressure can be made variable by providing the bolt 53c for pressure adjustment to screw.

DESCRIPTION OF SYMBOLS 1 Holding pressure valve 10 Valve box 11 Communication port 11a Seat surface 12 Inlet 13 Outlet 14 Primary flow path 15 Secondary flow path 16 Mounting hole 20 Valve body 21 Main body (valve body 20)
22 Valve shaft 22a Spring chamber 30 Valve rod 30a One end (of the valve rod 30)
30b The other end (of the valve stem 30)
31 Insertion hole 32 Engagement protrusion 33 Backflow prevention spring 34 Seal material (O-ring)
40 Spring 50 Spring chamber 50a One end (of spring chamber)
50b The other end (of the spring chamber)
51 Main body 52 One end side end wall 53 Other end side end wall (spring chamber cover)
53a Projection 53b Screw hole 53c Set pressure adjusting bolt 54 Communication hole 55 End plate 55 'Second end plate 56 Projection 57 Engaging recess 58 Projection 59 Flange 60, 60' Cylinder 65 Fastening member (bolt)
DESCRIPTION OF SYMBOLS 100 Oil-cooled screw compressor 130 Compressor main body 137 Suction flow path 140 Oil supply flow path 160 Receiver tank 165 Separator 200 Holding valve 210 Valve box 211 Communication port 211a Seat surface 212 Inlet 213 Outlet 214 Primary flow path 215 Secondary flow path 220 Valve body 222 Valve shaft 230 Piston 231 Insertion hole 234 Seal material (O-ring)
240 Spring 253 Top lid 253c Adjustment screw 255 'Sauce pan 259 Fixing ring 260 Cylinder

Claims (6)

A primary flow path that communicates with the inlet, a secondary flow path that communicates with the outlet, and a valve box having a communication port that communicates the primary flow path and the secondary flow path;
A valve body for opening and closing the communication port;
A valve stem to which the valve body is attached to one end;
A spring that presses the other end of the valve stem and biases the valve body in a direction to be seated on a seat surface provided in the communication port;
The communication hole provided in the end wall on one end side defining one end of the spring chamber that accommodates the spring communicates with the secondary flow path through a mounting hole provided in the valve box. The one end is detachably attached to the valve box,
The spring chamber includes an end plate that is movable in the spring chamber and cannot pass through the communication hole, and the spring chamber is disposed between the inner surface of the other end wall of the spring chamber and the end plate. Contain,
The other end of the valve stem abuts or is connected to the end plate via the mounting hole and the communication hole,
The communication port is closed by the valve body when the end plate is in a position in contact with the inner surface of the end wall on the one end side or in a position close to the end plate through a minute interval. Holding pressure valve.   The pressure-holding valve according to claim 1, wherein the end plate and the valve stem are formed as separate members.   The pressure-holding valve according to claim 1, wherein the end plate and the valve stem are integrally formed and connected.   A second end plate that can move in the spring chamber is provided between the inner wall of the end wall on the other end side of the spring chamber and the spring, and the spring is held between the end plate and the second end plate. In addition, a set pressure adjusting bolt is screwed into a screw hole penetrating the other end side wall of the spring chamber from the outside of the spring chamber toward the spring chamber, and a tip is in contact with the second end plate. The pressure-holding valve according to claim 1, wherein the pressure-holding valve is provided.   A cylinder that communicates with the communication hole and protrudes into the secondary flow path is provided at the one end of the spring chamber, and the valve rod is formed in a piston-like structure that slides in the cylinder in the axial direction. The pressure-holding valve according to any one of claims 1 to 4, wherein: 5. The mounting hole provided in the valve box is formed as a cylinder, and the valve rod is formed in a piston-like structure that slides in the cylinder in the axial direction. The holding pressure valve described in the item.

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