JP5111358B2 - Holding valve - Google Patents

Description

  The present invention relates to a pressure holding valve suitable for use in, for example, a scroll fluid compressor.

  In general, as a compression machine that compresses fluid such as air, by rotating the orbiting scroll relatively with respect to the fixed scroll, the air sucked from the suction port on the outer peripheral side is compressed in each compression chamber, A scroll type air compressor that discharges from a discharge port is known. The scroll type air compressor has a discharge port connected to an external storage tank, and stores the compressed air in the storage tank.

  Further, some scroll type air compressors are provided with a torsion coil spring between the rotary shaft and the orbiting scroll in order to prevent a shock when the rotary shaft is activated from acting on the orbiting scroll. Yes (see, for example, Patent Document 1).

JP 7-279864 A

  Generally, the scroll type air compressor is designed so that the behavior of the orbiting scroll is stabilized in a steady operation state in which each compression chamber has a prescribed pressure. On the other hand, Patent Document 1 only relieves the starting shock of the orbiting scroll by a torsion coil spring provided between the rotating shaft and the orbiting scroll. For this reason, there is a problem that the behavior of the orbiting scroll becomes unstable during the period from the start to the steady operation state, as in a normal air compressor.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to quickly change the pressure of the compressed fluid to a steady operation state when the fluid compressor is started, thereby changing the behavior of the operating portion. An object of the present invention is to provide a pressure maintaining valve that is stabilized.

In order to solve the above-described problem, a pressure-holding valve according to a first aspect of the present invention is a first valve body having a recess opened on the compressed fluid supply side, and is fitted into the recess of the first valve body so as to be able to advance and retract. The second valve body is displaced and opened in the recess immediately after the supply of the compressed fluid is started from the compressed fluid supply side, and the first valve body is opened. Is opened together with the second valve body when the pressure of the compressed fluid supplied from the compressed fluid supply side exceeds a set pressure, and the second valve body is compressed from the compressed fluid supply side. supply fluid Ru have a configuration you immediately closed when stopped.
A pressure holding valve according to a second aspect of the present invention has a valve port provided in the communication passage and formed with a communication hole serving as a passage for the compressed fluid, and is located on the compressed fluid supply side across the valve port. A first valve body that opens and closes the communication hole and a second valve body that is located on the compressed fluid discharge side and opens and closes the communication hole, and the first valve body is supplied from the compressed fluid supply side. When the pressure of the compressed fluid exceeds the set pressure, the second valve element opens immediately with the opening of the first valve element, and the second valve element When the supply of compressed fluid from the supply side stops, the valve is immediately closed.

  According to the present invention, one pressure holding valve can be provided with two functions of preventing the pressure from escaping at the time of starting and the function of preventing the back flow of the compressed fluid, thereby improving the assembly workability and cost. Can be reduced.

  Hereinafter, a case where the pressure holding valve according to the embodiment of the present invention is applied to a scroll type air compressor as a fluid compressor will be described as an example and described in detail with reference to the accompanying drawings.

  1 to 7 show a first embodiment according to the present invention. In the first embodiment, a pressure holding valve is integrally provided with a part of the fixed scroll as a valve case.

  In FIG. 1, reference numeral 1 denotes a scroll type air compressor as a scroll type fluid compressor according to the first embodiment. The scroll type air compressor 1 sucks and compresses air and supplies the compressed air to a storage tank 18 described later. As shown in FIG. 2, the scroll type air compressor 1 includes a casing 2, a fixed scroll 3, a turning scroll 5, an electric motor 7, a rotating shaft 8, an eccentric bush 11, a rotation prevention mechanism 14 and the like which will be described later. Yes.

  Reference numeral 2 denotes a casing constituting the outer shell of the scroll type air compressor 1, and the casing 2 is formed as a bottomed cylindrical body having an electric motor 7 attached to one side in the axial direction and opened on the other side in the axial direction. ing. The casing 2 includes a cylindrical portion 2A that is open on the other axial side (the fixed scroll 3 side), and an annular bottom 2B that is integrally formed on one axial side of the cylindrical portion 2A and extends radially inward. The cylindrical bearing mounting portion 2C protrudes from the inner peripheral side of the bottom portion 2B toward the other side in the axial direction.

  Further, in the cylindrical portion 2A of the casing 2, a turning scroll 5, an eccentric bush 11, a rotation prevention mechanism 14 and the like, which will be described later, are accommodated. Further, on the bottom 2B side of the casing 2, there are provided a plurality of pedestal portions 2D (only one is shown in FIG. 2) for receiving the thrust load applied to the orbiting scroll 5 through the anti-rotation mechanism 14. These pedestal portions 2 </ b> D are disposed at a predetermined interval in the circumferential direction of the casing 2.

  Reference numeral 3 denotes a fixed scroll which is fixedly provided on the opening end side of the casing 2 (cylinder portion 2A). The fixed scroll 3 includes a plate body 3A called an end plate formed in a disc shape, a spiral wrap portion 3B standing on the surface of the plate body 3A, and the wrap portion 3B from the outside in the radial direction. It is generally constituted by a cylindrical support portion 3C which is provided on the outer peripheral side of the plate body 3A so as to surround and is fastened to the opening end side of the casing 2 (tubular portion 2A) by a plurality of bolts 4 (only one is shown). Has been.

  Further, the fixed scroll 3 is provided with a valve case 3D which is located at the center of the back surface side of the plate body 3A and forms the outer shape of a pressure holding valve 21 which will be described later. The valve case 3D is formed in a bottomed cylindrical shape that becomes an accommodating recess 22 described later, and is disposed coaxially with a supply port 16 described later, for example.

  Reference numeral 5 denotes a turning scroll provided in the casing 2 so as to be capable of turning in the axial direction facing the fixed scroll 3. The orbiting scroll 5 includes a disk-shaped plate body 5A called a mirror plate, a spiral wrap portion 5B standing on the surface of the plate body 5A, and a back surface of the plate body 5A (on the side opposite to the wrap portion 5B). And a cylindrical boss portion 5 </ b> C that is attached to an eccentric bush 11 (described later) via a swivel bearing 13.

  Further, a plurality of mounting portions 5D (only one is shown in FIG. 2) to which a thrust receiver 14B of a rotation prevention mechanism 14 described later is fitted and mounted on the outer diameter side of the rear portion of the orbiting scroll 5 are orbited. The scrolls 5 are provided at intervals in the circumferential direction, and these attachment portions 5D are disposed at positions corresponding to the pedestal portions 2D of the casing 2.

  On the other hand, the center of the boss portion 5C of the orbiting scroll 5 is arranged eccentrically in the radial direction by a predetermined dimension (orbiting radius) predetermined with respect to the center of the fixed scroll 3. In this state, the wrap portion 5B of the orbiting scroll 5 is disposed so as to overlap the wrap portion 3B of the fixed scroll 3, and a plurality of compression chambers 6, 6,... Are formed between the wrap portions 3B, 5B. ing.

  The orbiting scroll 5 is driven by an electric motor 7 to be described later via the rotating shaft 8 and the eccentric bush 11 and performs an orbiting operation on the fixed scroll 3 in a state in which the rotation is restricted by the rotation prevention mechanism 14. Thereby, the compression chamber 6 on the outer diameter side among the plurality of compression chambers 6 sucks air from a suction port 15 described later, and continuously compresses the air in each compression chamber 6. And the compression chamber 6 of the center side discharges compressed air toward the exterior from the below-mentioned supply port 16.

  Here, the orbiting scroll 5 orbits relatively to the fixed scroll 3 and is configured to be held between the rolling parts of the fixed scroll 3 and the rotation prevention mechanism 14. Therefore, for example, a small gap (clearance) is provided in a sliding contact portion between the fixed scroll 3 and the orbiting scroll 5. In this case, the scroll type air compressor 1 starts the compression operation, and the pressure in each compression chamber 6 formed between the scrolls 3 and 5 becomes a specified pressure. When pressed to one side, the clearance between the orbiting scroll 5 and the rolling portion of the anti-rotation mechanism 14 becomes 0, and the clearance between the fixed scroll 3 and the orbiting scroll 5 is maximized, and the behavior of the orbiting scroll 5 is increased. Designed to be stable. The operation state in which the behavior of the orbiting scroll 5 is stable becomes the steady operation state of the air compressor 1.

  Reference numeral 7 denotes an electric motor as a drive source for turning the orbiting scroll 5, and the electric motor 7 rotationally drives a drive shaft 7A extending in the axial direction. Here, the drive shaft 7A of the electric motor 7 has its tip side (the other side in the axial direction) protruding toward the bottom 2B side of the casing 2, and is integrally connected to a rotating shaft 8 described later.

  Reference numeral 8 denotes a rotating shaft rotatably provided in the bearing mounting portion 2C of the casing 2 via a bearing 9 or the like. The rotating shaft 8 has a base end side (one side in the axial direction) as a driving shaft of the electric motor 7. It is connected to 7A and is rotationally driven by the electric motor 7. Further, a boss portion 5C of the orbiting scroll 5 is connected to the distal end side (the other side in the axial direction) of the rotary shaft 8 via an eccentric bush 11 and an orbiting bearing 13 which will be described later.

  In addition, a sub-weight 10 extending radially outward is integrally formed on the base end side of the rotating shaft 8, and the sub-weight 10 is centrifugally generated when a later-described balance weight 12 and the orbiting scroll 5 rotate. It has a function of canceling out that the force acts as an external force (moment force) in the direction of tilting the rotary shaft 8 or the like.

  Reference numeral 11 denotes a stepped cylindrical eccentric bush provided on the front end side of the rotary shaft 8. The eccentric bush 11 is in an eccentric state with the boss portion 5C side of the orbiting scroll 5 on the rotary shaft 8 via an orbiting bearing 13 described later. Are linked together. The eccentric bush 11 rotates integrally with the rotary shaft 8 and converts the rotation into a turning operation of the orbiting scroll 5. Further, a balance weight 12 is integrally formed on the outer peripheral side of the eccentric bush 11 in order to stabilize the turning operation of the turning scroll 5.

  Reference numeral 13 denotes a orbiting bearing disposed between the boss portion 5C of the orbiting scroll 5 and the eccentric bush 11, and the orbiting bearing 13 supports the boss portion 5C of the orbiting scroll 5 so as to be orbitable with respect to the eccentric bush 11. Thus, the orbiting scroll 5 is compensated for the orbiting operation with a predetermined orbiting radius with respect to the axis of the rotary shaft 8.

  Reference numeral 14 denotes a plurality of anti-rotation mechanisms provided between the bottom 2B of the casing 2 and the back side of the orbiting scroll 5, and each anti-rotation mechanism 14 is constituted by a so-called ball coupling mechanism. The rotation prevention mechanism 14 prevents rotation of the orbiting scroll 5 and receives a thrust load via thrust receivers 14A and 14B, balls 14C and the like which will be described later. These anti-rotation mechanisms 14 are disposed between the pedestal portions 2D of the casing 2 and the mounting portions 5D of the orbiting scroll 5, respectively.

  That is, the anti-rotation mechanism 14 composed of a ball coupling is pivoted so as to be opposed to the first thrust receiver 14A fixedly provided on the pedestal 2D side of the casing 2 and the first thrust receiver 14A in the axial direction. The second thrust receiver 14B provided on the mounting portion 5D side of the scroll 5 and a spherical ball 14C provided so as to roll between the first and second thrust receivers 14A and 14B are configured. Yes.

  The ball 14C of the rotation prevention mechanism 14 is formed as a sphere of a material having high rigidity such as a steel ball, for example, and a thrust load applied to the plate body 5A of the orbiting scroll 5 is applied together with the thrust receivers 14A and 14B. It is received on the pedestal 2D side of the casing 2.

  Reference numeral 15 denotes a suction port provided on the outer peripheral side of the fixed scroll 3. The suction port 15 sucks air from the outside through, for example, an intake filter (not shown), and the sucked air continuously flows in each compression chamber 6 as the orbiting scroll 5 rotates. Is compressed.

  Reference numeral 16 denotes a supply port provided on the center side of the fixed scroll 3, and the supply port 16 constitutes a compressed fluid supply side opening to the pressure holding valve 21. The supply port 16 discharges compressed air from the compression chamber 6 on the innermost diameter side among the plurality of compression chambers 6 toward the storage tank 18 via a pressure holding valve 21 described later. When viewed from the compressor 1, it is also a discharge port.

  Reference numeral 17 denotes a discharge port serving as a compressed air discharge side opening provided by extending the fixed scroll 3 in the radial direction. The discharge port 17 has an upstream side located on the center side of the fixed scroll 3 connected to the bottom 22 </ b> A of the housing recess 22. On the other hand, the discharge port 17 is connected to a storage tank 18 described later on the downstream side located on the outer side in the radial direction. Thereby, the compressed air discharged from the air compressor 1 is discharged from the discharge port 17 toward the storage tank 18 to be described later when the pressure holding valve 21 is in the open state.

  Reference numeral 18 denotes an external storage tank (see FIG. 1) for storing compressed air as a compressed fluid. The storage tank 18 is connected to a discharge port 17 of a pressure holding valve 21 described later via a conduit 19 or the like. And the storage tank 18 stores temporarily the compressed air discharged from the compression chamber 6 of the scroll type air compressor 1 through the supply port 16 and the pressure-holding valve 21, and this is pneumatic equipment (not shown). Etc. as a power source.

  Next, the pressure holding valve 21 according to the first embodiment provided between the scroll air compressor 1 and the storage tank 18 will be described. This pressure holding valve 21 prevents the compressed air from escaping to the external storage tank 18 immediately after starting the compression operation (immediately after starting), and compresses the compressed air in the storage tank 18 and the conduit 19 when the operation is stopped. And a function of preventing the flow back to the chamber 6 side. Further, the pressure holding valve 21 of the present embodiment is provided integrally with the fixed scroll 3.

  That is, 21 is a pressure holding valve according to the first embodiment, and the pressure holding valve 21 is disposed in the valve case 3D of the fixed scroll 3. As shown in FIG. 3, the pressure holding valve 21 includes an accommodation recess 22, a communication path 23, a first valve body 25, a first spring member 27, a second valve body 28, and a second spring member 29, which will be described later. Etc.

  Reference numeral 22 denotes an accommodating recess of the pressure-holding valve 21 provided in the valve case 3D of the fixed scroll 3. This accommodation recessed part 22 is formed as a bottomed hole opened toward the other side in the axial direction. In addition, the supply recess 16 communicates with the housing recess 22 at the center of the bottom portion 22A, and the discharge port 17 communicates near the bottom portion 22A of the inner peripheral surface 22B. Further, the bottom portion 22A is formed with a first valve seat 22C having a reduced diameter on the outer peripheral side, and a second valve seat 22D is formed around the supply port 16.

  Reference numeral 23 denotes a communication path (see FIGS. 3 to 6) that communicates between the supply port 16 and the discharge port 17. The communication path 23 is formed as a space from the bottom 22A defined by the first valve body 25 described later to the discharge port 17 through the housing recess 22, and when the first valve body 25 is opened. The air flowing in from the supply port 16 is circulated to the discharge port 17 side.

  Reference numeral 24 denotes a lid-like spring receiver attached so as to close the opening side of the accommodating recess 22, and the spring receiver 24 receives the urging force of the first spring member 27. An air passage 24A that opens a spring chamber 26 (described later) to the atmosphere is formed in the center of the spring receiver 24.

  Reference numeral 25 denotes a first valve body provided in the housing recess 22. The first valve body 25 is inserted between the bottom portion 22A and the spring receiver 24 so as to be displaceable in the axial direction. Further, the first valve body 25 is formed in a bottomed cylindrical shape by a bottom surface portion 25A facing the bottom portion 22A and a cylindrical portion 25B extending from the outer periphery of the bottom surface portion 25A along the inner peripheral surface 22B. . Further, a valve body mounting recess 25C for mounting the shaft portion 28A of the second valve body 28 and the second spring member 29 is formed at the center position of the bottom surface portion 25A, and the housing recess 22 is formed on the outer peripheral side. An annular valve portion 25D that is attached to and detached from the first valve seat 22C is formed. Further, a seal member 25E is attached to the outer peripheral side of the cylindrical portion 25B to hold the space between the inner peripheral surface 22B and the inner periphery 22B. A spring chamber 26 opened to the atmosphere is formed between the first valve body 25 and the spring receiver 24, and a first spring member 27 described later is disposed in the spring chamber 26.

  The first valve body 25 is normally closed by closing the valve portion 25D provided on the outer peripheral side of the bottom surface portion 25A on the first valve seat 22C of the housing recess 22 and shutting off the communication passage 23. ing. On the other hand, when the pressure of the communication path 23 becomes higher than the set pressure, that is, the first spring member described later has a pressing force due to the differential pressure between the pressure of the communication path 23 and the pressure of the spring chamber 26 (atmospheric pressure). When the pressure becomes greater than the urging force 27, the valve is opened, and the compressed air is circulated through the communication passage 23. As described above, the first valve body 25 has a pressure-holding function that keeps the first valve body 25 from escaping until the pressure in the compression chamber 6 reaches the set pressure at the time of activation.

  Reference numeral 27 denotes a first spring member located in the spring chamber 26 and provided between the first valve body 25 and the spring receiver 24. The spring member 27 biases the first valve body 25 in the valve closing direction.

  Here, the biasing force of the first spring member 27 accommodates the first valve body 25 until the pressure of the compressed air flowing into the communication passage 23 from the supply port 16 of the scroll type air compressor 1 reaches the set pressure. The first valve body 25 is set to be separated from the first valve seat 22C when the set pressure is exceeded by being seated on the first valve seat 22C of the recess 22. Further, the set pressure at this time is a pressure at which the orbiting scroll 5 is pressed by the pressure in the compression chamber 6 and the orbiting scroll 5 can orbit in a stable state.

  Reference numeral 28 denotes a second valve body attached to the valve body mounting recess 25 </ b> C of the first valve body 25. The second valve body 28 includes a shaft portion 28A that is inserted into the valve body mounting recess 25C so as to be able to advance and retreat, and a disc-shaped valve portion 28B provided at the tip of the shaft portion 28A. Yes.

  The second valve body 28 is normally closed by causing the valve portion 28B to be seated on the second valve seat 22D of the housing recess 22 by the biasing force of the second spring member 29 described later. And the communication path 23 are blocked. On the other hand, when the compressed air is discharged from the supply port 16, the valve is immediately opened to allow the compressed air to flow from the supply port 16 to the communication path 23. Further, when the supply of compressed air from the supply port 16 is stopped, the valve portion 28B is immediately seated on the second valve seat 22D by the urging force of the second spring member 29, and the storage tank 18, conduit The compressed air in 19 is prevented from flowing back to the compression chamber 6 side. Thus, the 2nd valve body 28 has a backflow prevention function of compressed air.

  Reference numeral 29 denotes a second spring member housed in the valve body mounting recess 25C of the first valve body 25. The spring member 29 urges the second valve body 28 in the valve closing direction, and is provided between the valve body mounting recess 25C and the valve portion 28B of the second valve body 28. Further, the biasing force of the second spring member 29 is a value at which the second valve element 28 is easily opened even when the discharge pressure from the compression chamber 6 is weak, for example, a spring force weaker than that of the first spring member 27. Is set to

  The scroll air compressor 1 according to the first embodiment has the above-described configuration. Next, the operation of the scroll air compressor 1 will be described.

  First, when the scroll type air compressor 1 is rotationally driven about the axis by the electric motor 7 about the rotation shaft 8 and the eccentric bush 11, the orbiting scroll 5 is in a state in which rotation is restricted by the rotation prevention mechanism 14. Turn operation with turning radius.

  As a result, the compression chambers 6 defined between the wrap portion 3B of the fixed scroll 3 and the wrap portion 5B of the orbiting scroll 5 are continuously reduced from the outer diameter side toward the inner diameter side. Of these compression chambers 6, the compression chamber 6 on the outer diameter side sucks air as a fluid from the suction port 15, and compresses the air continuously in each compression chamber 6, while compressing the air on the inner diameter side. Compressed air is supplied from 6 to the pressure-holding valve 21 through the supply port 16.

  Next, the relationship between the function of the pressure-holding valve 21 according to the first embodiment and the turning operation of the orbiting scroll 5 will be described.

  First, when the orbiting scroll 5 is activated by the electric motor 7 (the orbiting operation is started), each compression chamber 6 is almost at atmospheric pressure, and therefore the orbiting scroll 5 can be pressed by the pressure of each compression chamber 6. Can not. For this reason, the behavior of the orbiting scroll 5 may become unstable from the start until the pressure in the compression chamber 6 increases.

  At this time, as shown in FIG. 4, the pressure holding valve 21 opens the second valve body 28 with the supply of compressed air, but the valve portion 25 </ b> D of the first valve body 25 is the first in the housing recess 22. The state where the valve seat 22C is seated and closed is maintained, and the communication path 23 is blocked. Accordingly, since the air compressed in each compression chamber 6 is not discharged to the outside, the pressure in each compression chamber 6 can be quickly raised to the set pressure. Thereby, the behavior of the orbiting scroll 5 can be stabilized in a short time after starting the scroll type air compressor 1.

  When the pressure in the compression chamber 6 (communication passage 23) exceeds a set value, the first valve body 25 is against the first spring member 27 as shown in FIG. , And the compressed air is discharged toward the storage tank 18 through the discharge port 17 and the conduit 19. At this time, since the first valve body 25 is not fully opened but only opened small, the pressure drop in the compression chamber 6 can be prevented.

  Next, when the pressure in the compression chamber 6 exceeds the set value and reaches a steady operation state, the first valve body 25 comes into contact with the spring receiver 24 and is fully opened as shown in FIG. A large amount of compressed air can be supplied to the storage tank 18 through 23.

  On the other hand, when the operation of the scroll type air compressor 1 is stopped, the compressed air in the storage tank 18 or the conduit 19 may flow backward to the compression chamber 6 and cause the orbiting scroll 5 to rotate reversely. However, as shown in FIG. 7, when the compressed air flows back through the communication passage 23 from the discharge side to the supply side, the pressure holding valve 21 is driven by the biasing force of the second spring member 29 regardless of the pressure in the communication passage 23. Since the second valve body 28 is immediately closed, the communication path 23 (supply port 16) can be shut off, and the backflow of compressed air can be prevented.

  Thus, according to the first embodiment, the pressure holding valve 21 includes the communication passage 23 that communicates the supply port 16 and the discharge port 17 and the pressure of the compressed air supplied to the communication passage 23 reaches the set pressure. Until the set pressure is exceeded, the first valve element 25 that opens the communication passage 23 and the communication passage 23 when the supply of compressed air from the air compressor 1 stops. The second valve element 28 prevents the compressed air from flowing backward from the discharge side to the supply side.

  As a result, when the scroll type air compressor 1 is started, the pressure in the compression chamber 6 is maintained until the pressure in the compression chamber 6 increases, so that the turning operation of the orbiting scroll 5 can be performed in a short time from the start. It can be stabilized, and wear and damage due to rattling can be prevented. Moreover, when the scroll type air compressor 1 is stopped, the compressed air which is going to flow backward can be shut off immediately to prevent the orbiting scroll 5 from rotating backward. The pressure holding function and the compressed air backflow prevention function can be obtained by one pressure holding valve 21.

  As a result, since only one pressure holding valve 21 needs to be attached to the scroll type air compressor 1, it is possible to easily cope with an existing compressor, improving assembly workability and reducing costs. You can plan.

  In addition, the pressure holding valve 21 can fully open the communication passage 23 in a steady operation state where the pressure in the compression chamber 6 exceeds the set pressure, and therefore supplies a large amount of compressed air to the storage tank 18 through the communication passage 23. The compressed air can be efficiently stored in the storage tank 18.

  Next, FIGS. 8 to 11 show a second embodiment of the present invention. A feature of the present embodiment is that the holding valve has a valve port in which a communication hole serving as a compressed fluid passage is formed, and is located on the compressed fluid supply side across the valve port to open and close the communication hole. The first valve body is provided, and the second valve body that opens and closes the communication hole is provided on the compressed fluid discharge side. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 8, reference numeral 31 denotes a pressure holding valve according to the second embodiment which is used in place of the pressure holding valve 21 according to the first embodiment. The pressure holding valve 31 is integrally attached to the valve case 3D ′ of the fixed scroll 3 ′. As shown in FIG. 9, the pressure holding valve 31 includes an accommodating recess 32, a communication path 33, a valve port 35, a first valve body 36, a first spring member 38, a second valve body 39, and a second valve. The spring member 40 and the like.

  An accommodation recess 32 is provided in the valve case 3D 'of the fixed scroll 3'. The accommodation recess 32 is formed as a bottomed hole that opens toward the other side in the axial direction. In the housing recess 32, the supply port 16 'communicates with the inner peripheral surface 32B on the bottom 32A side, and the discharge port 17' communicates with the inner peripheral surface 32B on the opening side. A mounting cylinder portion 32C for detachably mounting the second valve element 39 is provided in the bottom portion 32A so as to project in the axial direction, and a valve port 35 is mounted at an intermediate position in the axial direction of the inner peripheral surface 32B. The mounting step 32D is formed with a reduced diameter. The second valve body 39 is attached to the mounting cylinder portion 32C so as to be displaceable by forming a gap, so that the inside and the outside of the mounting cylinder portion 32 have the same pressure.

  Reference numeral 33 denotes a communication path that communicates between the supply port 16 ′ and the discharge port 17 ′. The communication path 33 is provided from the intermediate portion in the axial direction of the housing recess 32 to the bottom portion 32 </ b> A. When the first valve body 36 and the second valve body 39 are opened, the communication path 33 allows compressed air to flow from the supply port 16 ′ to the discharge port 17 ′ through a communication hole 35 A of a valve port 35 described later. It is to be distributed.

  Reference numeral 34 denotes a lid-like spring receiver attached so as to close the opening side of the housing recess 32, and the spring receiver 34 receives the urging force of the first spring member 38. An air passage 34A that opens a spring chamber 37 (described later) to the atmosphere is formed in the center of the spring receiver 34.

  Reference numeral 35 denotes a disk-like valve port attached to the attachment step 32D in the housing recess 32. The communication port 35A forms a part of the communication passage 33 and serves as a compressed air passage at the central position of the valve port 35. Is formed. The valve port 35 is formed with a first valve seat 35B located on the other side of the communication hole 35A, and the first valve seat 35B has a valve portion 36B of the first valve body 36 attached and detached. To do. On the other hand, on the opposite side of the communication hole 35A, a second valve seat 35C is formed on which the second valve body 39 is seated.

  Reference numeral 36 denotes a first valve body provided in the housing recess 32, and the first valve body 36 is inserted between the valve port 35 and the spring receiver 34 so as to be displaceable in the axial direction. The first valve body 36 includes a cylindrical piston portion 36A and a valve portion 36B that protrudes in the axial direction from the piston portion 36A and is attached to and detached from the first valve seat 35B of the valve port 35. A seal member 36C is attached to the outer peripheral side of the portion 36A to hold the space between the inner peripheral surface 32B and the inner peripheral surface 32B. The piston portion 36A of the first valve body 36 forms a spring chamber 37 that is isolated from the communication passage 33 between the piston portion 36A and the spring receiver 34, and the spring chamber 37 is interposed via the atmospheric passage 34A of the spring receiver 34. Open to the atmosphere.

  The first valve body 36 normally closes the communication passage 33 by seating the valve portion 36B on the first valve seat 35B of the valve port 35 and closing the valve. On the other hand, when the pressure of the communication path 33 becomes higher than the set pressure, that is, the first spring member described later has a pressing force due to the differential pressure between the pressure of the communication path 33 and the pressure of the spring chamber 37 (atmospheric pressure). When the pressure becomes larger than 38, the valve is opened, and the compressed air is circulated through the communication path 33. As described above, the first valve body 36 has a pressure-holding function that keeps the first valve body 36 from escaping until the pressure in the compression chamber 6 reaches the set pressure at the time of activation.

  Reference numeral 38 denotes a first spring member located in the spring chamber 37 and provided between the first valve body 36 and the spring receiver 34. The spring member 38 biases the first valve body 36 in the valve closing direction.

  Here, the urging force of the first spring member 38 causes the first valve body 36 to remain until the pressure of the compressed air flowing into the communication passage 33 from the supply port 16 ′ of the scroll type air compressor 1 reaches the set pressure. The first valve body 36 is set to be seated on the first valve seat 35B of the valve port 35, and when the set pressure is exceeded, the first valve body 36 is separated from the first valve seat 35B. Further, the set pressure at this time is a pressure at which the orbiting scroll 5 is pressed by the pressure in the compression chamber 6 and the orbiting scroll 5 can orbit in a stable state.

  Reference numeral 39 denotes a second valve body disposed to face the first valve body 36 with the valve port 35 interposed therebetween. The second valve element 39 is normally seated on the second valve seat 35C of the valve port 35 by an urging force of a second spring member 40, which will be described later, and closes the communication passage 33. . On the other hand, when the first valve body 36 is opened, the valve is opened almost simultaneously with the opening of the first valve body 36 and the compressed air is circulated through the communication passage 33. Further, when the supply of compressed air from the supply port 16 ′ stops, the urging force of the second spring member 40 immediately sits on the second valve seat 35 C of the valve port 35 and closes the valve, The compressed air in the conduit 19 is prevented from flowing back to the compression chamber 6 side. Thus, the 2nd valve body 39 has a backflow prevention function of compressed air.

  Reference numeral 40 denotes a second spring member housed in the mounting cylinder portion 32C of the housing recess 32. The spring member 40 biases the second valve body 39 in the valve closing direction. Further, the biasing force of the second spring member 40 is a value at which the second valve element 39 can be easily opened even when the discharge pressure from the compression chamber 6 is weak, for example, a spring force weaker than that of the first spring member 38. Is set to

  Next, the operation of the pressure holding valve 31 according to the second embodiment will be described with reference to FIGS.

  First, when the scroll type air compressor 1 is started, as shown in FIG. 9, the valve portion 36B of the first valve body 36 is seated on the first valve seat 35B of the valve port 35 and is closed. The passage 33 is blocked. Therefore, since the air compressed in each compression chamber 6 is not discharged outside, the pressure in each compression chamber 6 can be quickly increased to the set pressure. Thereby, the behavior of the orbiting scroll 5 can be stabilized in a short time after starting the scroll type air compressor 1.

  When the pressure in the compression chamber 6 (communication passage 33) exceeds a set value, the first valve body 36 opens against the first spring member 38 as shown in FIG. Since the second valve body 39 opens almost simultaneously with the opening of the first valve body 36, compressed air can be supplied to the storage tank 18 through the communication path 33, the discharge port 17, and the conduit 19. it can. At this time, since the first valve body 36 is not fully opened but only opened small, the pressure drop in the compression chamber 6 can be prevented.

  Next, when the pressure in the compression chamber 6 exceeds the set value and reaches a steady operation state, the first valve body 36 is brought into full contact with the spring receiver 34 as shown in FIG. A large amount of compressed air can be supplied to the storage tank 18 through 33.

  On the other hand, when the operation of the scroll type air compressor 1 is stopped, the compressed air in the storage tank 18 or the conduit 19 may flow backward to the compression chamber 6 and cause the orbiting scroll 5 to rotate reversely. However, as shown in FIG. 9, when the compressed air flows back through the communication path 33 from the discharge side to the supply side, the pressure holding valve 31 does not depend on the pressure of the communication path 33, but is biased by the second spring member 40. The second valve body 39 can be closed, and the communication passage 33 can be blocked to prevent the backflow of compressed air.

  Thus, also in the second embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above.

  Next, FIG. 12 and FIG. 13 show a third embodiment of the present invention. The feature of this embodiment is that the pressure holding valve is provided independently of the fluid compressor. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 12, reference numeral 41 denotes a pressure holding valve according to the third embodiment which is used in place of the pressure holding valve 21 according to the first embodiment. The pressure holding valve 41 is provided between the compressor 1 and the storage tank 18 independently of the scroll air compressor 1. As shown in FIG. 13, the pressure holding valve 41 according to the third embodiment provided separately from the scroll type air compressor 1 includes a valve case 42, a communication passage 43, a first valve body 45, a first valve body 45, and the like. 1 spring member 47, second valve body 48, second spring member 49, and the like. The pressure holding valve 41 is connected to the discharge port 50 of the scroll air compressor 1 via a separate conduit 51.

  Reference numeral 42 denotes a valve case forming the outer shape of the pressure-holding valve 31. The valve case 42 is formed in a bottomed cylindrical shape by a bottom portion 42A and a cylindrical portion 42B, and a supply port 42C serving as an opening on the compressed fluid supply side is formed in the bottom portion 42A. The cylinder portion 42B is provided with a discharge port 42D serving as a compressed fluid discharge side opening. Further, the inner end surface of the bottom portion 42A becomes a flat first valve seat 42E on which a first valve body 45 described later is seated, and the end portion of the supply port 42C serving as the inner peripheral end thereof is the second valve body 48. Is a second valve seat 42F that is seated. Further, a seal member 42G is mounted on the inner peripheral side of the cylindrical portion 42B to hold the space between the first valve body 45 and the first valve body 45 in an airtight manner.

  43 is a communication path (illustrated only in a blocked state) for communicating between the supply port 42C and the discharge port 42D. The communication passage 43 allows compressed air to flow from the supply port 42C to the discharge port 42D when the first valve body 45 and the second valve body 48 are opened.

  Reference numeral 44 denotes a lid-like spring receiver attached so as to close the opening side of the valve case 42, and the spring receiver 44 receives the biasing force of the first spring member 47. An air passage 44A that opens a spring chamber 46 (described later) to the atmosphere is formed in the center of the spring receiver 44.

  Reference numeral 45 denotes a first valve body provided in the cylinder portion 42B of the valve case 42. The first valve body 45 is located between the bottom portion 42A and the spring receiver 44 and is inserted so as to be axially displaceable. It is fitted. The first valve body 45 includes a piston portion 45A that is in sliding contact with the cylindrical portion 42B, a valve portion 45B that is reduced in diameter from one end of the piston portion 45A, protrudes in the axial direction, and is attached to and detached from the first valve seat 42E. And a stepped valve accommodating hole 45C formed from the valve portion 45B to the piston portion 45A, and the outer peripheral surface of the piston portion 45A is in air-tight sliding contact with a seal member 42G provided in the valve case 42. . The piston portion 45A of the first valve body 45 forms a spring chamber 46 that is isolated from the communication passage 43 between the piston portion 45A and the spring receiver 44, and the spring chamber 46 passes through the atmospheric passage 44A of the spring receiver 44. Open to the atmosphere.

  The first valve body 45 normally closes the communication passage 43 by seating the valve portion 45B on the first valve seat 42E of the valve case 42 and closing it. On the other hand, when the pressure of the communication passage 43 becomes higher than the set pressure, that is, the first spring member described later has a pressing force due to the differential pressure between the pressure of the communication passage 43 and the pressure of the spring chamber 46 (atmospheric pressure). When the pressure becomes larger than the urging force of 47, the valve is opened, and the compressed air is circulated through the communication passage 43. As described above, the first valve body 45 has a pressure-holding function that keeps the first valve body 45 from escaping until the pressure in the compression chamber 6 reaches the set pressure at the time of activation.

  Reference numeral 47 denotes a first spring member located in the spring chamber 46 and provided between the first valve body 45 and the spring receiver 44. The spring member 47 biases the first valve body 45 in the valve closing direction.

  Here, the urging force of the first spring member 47 causes the first valve body 45 to remain in the valve case until the pressure of the compressed air discharged from the scroll air compressor 1 and flowing into the communication passage 43 reaches a set pressure. 42, the first valve body 45 is set to be separated from the first valve seat 42E when the set pressure is exceeded. Further, the set pressure at this time is a pressure at which the orbiting scroll 5 is pressed by the pressure in the compression chamber 6 and the orbiting scroll 5 can orbit in a stable state.

  Reference numeral 48 denotes a second valve body provided in the valve accommodating hole 45C of the first valve body 45, and the second valve body 48 is configured as a ball valve body. Further, the second valve body 48 is normally closed by being seated on the second valve seat 42F of the valve case 42 by the biasing force of the second spring member 49 described later, and the communication passage 43 is shut off. Yes. On the other hand, when compressed air is supplied from the supply port 42C, the valve is opened and the compressed air is circulated through the communication port 43 from the supply port 42C. Further, when the supply of compressed air from the supply port 42C stops, the urging force of the second spring member 49 immediately sits on the second valve seat 42F of the valve case 42 to close the valve, and the storage tank 18, conduit The compressed air in 19 is prevented from flowing back to the compression chamber 6 side through the conduit 50. Thus, the 2nd valve body 48 has a backflow prevention function of compressed air.

  Reference numeral 49 denotes a second spring member housed in the mounting cylinder portion 32C of the housing recess 32. The spring member 49 biases the second valve body 48 in the valve closing direction. Further, the biasing force of the second spring member 49 is a value at which the second valve body 48 is easily opened even when the discharge pressure from the compression chamber 6 is weak, for example, a spring force weaker than that of the first spring member 47. Is set to

  In addition, since operation | movement of each valve body 45,48 of the holding pressure valve 41 by 3rd Embodiment is substantially the same as 1st Embodiment mentioned above, the description shall be abbreviate | omitted.

  Thus, also in the third embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the above-described embodiments. In particular, according to the third embodiment, since the pressure holding valve 41 can be provided separately from the scroll type air compressor 1, it can be easily attached to an existing compressor without any special processing. Can do.

  In each embodiment, the scroll type air compressor 1 in which the electric motor 7 is integrally provided as a scroll type fluid compressor has been described as an example. However, the present invention is not limited to this. For example, the present invention may be applied to a scroll type air compressor in which an electric motor is provided separately and drives a orbiting scroll through a belt or the like. It can be widely applied.

As described in the above embodiments, the pressure holding valve discharges the compressed fluid to the outside until the pressure of the compressed fluid reaches the set pressure when the fluid compressor is started and the compressed fluid is supplied. You can avoid it.

  Accordingly, the pressure holding valve can increase the pressure of the supplied compressed fluid to a set pressure in a short time when the fluid compressor is started. For example, when the fluid compressor is a scroll type fluid compressor, the operation is performed. The behavior of the orbiting scroll, which is a part, can be stabilized. In addition, the pressure holding valve can open a large amount of compressed fluid to the outside efficiently by opening when the set pressure is exceeded. Further, the pressure holding valve can immediately stop the backflow of the compressed fluid from the compressed fluid discharge side when the supply of the compressed fluid is stopped.

  As a result, since only one pressure holding valve is attached to the fluid compressor, it is possible to obtain a function of maintaining the pressure at the time of startup and a function of preventing the back flow of the compressed fluid. Therefore, the assembly workability can be improved and the cost can be reduced.

According to the first aspect of the present invention, when the supply of the compressed fluid is started from the compressed fluid supply side, the second valve body is immediately displaced in the recess and opened. Further, when the pressure of the compressed fluid supplied from the compressed fluid supply side exceeds the set pressure, the first valve body is opened together with the second valve body. Further, when the supply of the compressed fluid from the compressed fluid supply side is stopped, the second valve body is immediately closed to prevent the back flow of the compressed fluid.

According to the invention of claim 2 , when the pressure of the compressed fluid supplied from the compressed fluid supply side exceeds the set pressure, the first valve body is opened and the second valve body is the first valve. Opens immediately as the body opens. Further, when the supply of the compressed fluid from the compressed fluid supply side is stopped, the second valve body is immediately closed, thereby preventing the back flow of the compressed fluid.

According to the invention of claim 3 , when the compressed fluid supply side of the pressure holding valve is connected to the discharge port of the scroll type fluid compressor, the pressure in the compression chamber between the scrolls is increased in a short time from the start of operation. And the behavior of scrolling can be stabilized.

It is a whole block diagram which shows the pressure-holding valve by the 1st Embodiment of this invention with a scroll type air compressor and a storage tank. It is a longitudinal cross-sectional view shown in the state which assembled | attached the pressure retaining valve by 1st Embodiment to the scroll type air compressor. It is a longitudinal cross-sectional view of the principal part expansion which shows the pressure-holding valve by 1st Embodiment in the operation stop state of a scroll type air compressor. It is a longitudinal cross-sectional view of the principal part expansion which shows a pressure holding valve in the state immediately after starting of a scroll type air compressor. It is a longitudinal cross-sectional view of the principal part expansion which shows a pressure holding valve in the state when the pressure of a communicating path exceeds a setting value. It is a longitudinal cross-sectional view of the principal part expansion which shows a pressure holding valve in the steady operation state of a scroll type air compressor. It is a longitudinal cross-sectional view of the principal part expansion which shows a pressure holding valve in the state immediately after stopping operation | movement of a scroll type air compressor. It is a longitudinal cross-sectional view which shows the pressure-holding valve by the 2nd Embodiment of this invention in the state assembled | attached to the scroll type air compressor. It is a longitudinal cross-sectional view of the principal part expansion which shows the pressure-holding valve by 2nd Embodiment in the operation stop state of a scroll type air compressor, the state immediately after starting, or the state immediately after operation stop. It is a longitudinal cross-sectional view of the principal part expansion which shows a pressure holding valve in the state when the pressure of a communicating path exceeds a setting value. It is a longitudinal cross-sectional view of the principal part expansion which shows a pressure holding valve in the steady operation state of a scroll type air compressor. It is a whole block diagram which shows the pressure-holding valve by the 3rd Embodiment of this invention with a scroll type air compressor, a conduit | pipe, and a storage tank. It is a longitudinal cross-sectional view which expands and shows the pressure-holding valve by 3rd Embodiment.

Explanation of symbols

1 Scroll type air compressor (scroll type fluid compressor)
3, 3 ', 3 "fixed scroll 3D, 3D', 42 Valve case 5 Orbiting scroll 6 Compression chamber 15 Suction port 16, 16 ', 42C Supply port (compressed fluid supply side opening)
17, 17 ', 42D Discharge port (compressed fluid discharge side opening)
18 Storage tank 19, 51 Conduit 21, 31, 41 Pressure holding valve 22, 32 Housing recess 23, 33, 43 Communication path 25, 36, 45 First valve element 27, 38, 47 First spring member 28, 39, 48 Second valve body 29, 40, 49 Second spring member 35 Valve port 35A Communication hole

Claims (3)

There is an opening on the compressed fluid supply side and the compressed fluid discharge side, and a communication path is provided to connect the supply side opening to the discharge side opening, and the compressed fluid supply side is connected to the compressed fluid supply side. A holding valve that prevents backflow into the
A first valve body having a recess opened on the compressed fluid supply side, and a second valve body inserted into the recess of the first valve body so as to be able to advance and retract,
When the supply of the compressed fluid is started from the compressed fluid supply side, the second valve body is displaced and opened in the recess immediately after the compressed fluid supply is started,
The first valve body opens with the second valve body when the pressure of the compressed fluid supplied from the compressed fluid supply side exceeds a set pressure,
The second valve body is a pressure-holding valve configured to close immediately when the supply of compressed fluid from the compressed fluid supply side stops. There is an opening on the compressed fluid supply side and the compressed fluid discharge side, and a communication path is provided to connect the supply side opening to the discharge side opening, and the compressed fluid supply side is connected to the compressed fluid supply side. A holding valve that prevents backflow into the
A first valve body that is provided in the communication path and has a valve port in which a communication hole serving as a compressed fluid path is formed, and is located on the compressed fluid supply side across the valve port to open and close the communication hole And a second valve body that is located on the compressed fluid discharge side and opens and closes the communication hole,
The first valve body is opened when the pressure of the compressed fluid supplied from the compressed fluid supply side exceeds a set pressure, and the second valve body is associated with the opening of the first valve body. Open immediately,
The second valve body is a pressure-holding valve configured to close immediately when the supply of compressed fluid from the compressed fluid supply side stops. Wherein the compressed fluid supply side, the pressure holding valve according to claim 1 or 2 comprising a structure for connecting the discharge port of the scroll fluid compressor for compressing a fluid between the two scrolls operate relatively pivot .

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