JP2006183531A - Multistage compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the reduction in a starting load, etc., and to simplify the structure by relieving the residual pressure from a compression chamber of a high-pressure side compression portion into the outside at the time of an operation stop. <P>SOLUTION: A partition 27 is installed in a cylinder head 22 of the high-pressure side compression portion 16 to demarcate a suction chamber 23 and a discharge chamber 24 between a valve plate 18, and a hollow space 27A is installed in the partition 27. A small-diameter orifice 28 for relieving the residual pressure in the compression chamber 20 is bored in the partition 27 to make the suction chamber 23 inside communicate with the space 27A inside by the orifice 28. A silencer filter 30 is installed in the space 27A of the partition 27, and a small-diameter exhaust port 29 positined downstrem of the orifice 28, and normally communicating with the space 27A is installed in the upper surface side of the cylinder head 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multistage compressor suitably used for compressing a gas such as air in multiple stages of two stages or three stages or more.

  In general, in order to compress a gas such as air in two or more stages, a multistage compression such as a reciprocating air compressor configured to compress the gas compressed in the low pressure side compression section to a higher pressure in the high pressure side compression section The machine is known (for example, see Patent Document 1).

  In this type of conventional multistage compressor, two discharge chambers are formed in a cylinder head mounted on a high pressure side cylinder in order to reduce the starting load of the high pressure side compression section, and one discharge The chamber is connected to an external air tank or the like, and the other discharge chamber is connected to the control valve mechanism via an unloading pipe.

  The control valve mechanism is controlled to open and close by using the pressure in the air tank when the compressor is stopped or in a no-load operation, and the pressure (residual pressure) remaining in the high-pressure side cylinder is controlled. It escapes to the outside through the unloading piping. Thereby, the high pressure side compression part can reduce the load etc. at the time of restarting a piston within a cylinder.

JP-A-10-246184

  In the prior art described above, two discharge chambers are formed in a cylinder head mounted on a cylinder on the high pressure side, and one discharge chamber is connected to an external air tank and the other discharge chamber is unloaded. It is connected to the control valve mechanism via a load pipe.

  However, the control valve mechanism in this case is configured to perform open / close control using the pressure in the air tank when the compressor is stopped or no-load operation, so the valve structure becomes complicated and the number of parts is reduced. There is a problem that workability at the time of assembling deteriorates.

  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 easily release the residual pressure remaining in the compression chamber of the high-pressure side compression unit to the outside when the operation is stopped, An object of the present invention is to provide a multistage compressor that can reduce the starting load and the like, and can improve the workability during assembly by simplifying the structure.

  In order to solve the above-described problems, the present invention compresses a low-pressure gas while sucking it from the suction chamber into the compression chamber, discharges the compressed gas to the discharge chamber, and discharges of the low-pressure side compression portion A multi-stage compression comprising a suction chamber connected to the chamber via an intermediate flow path, and a high-pressure side compression section that compresses the gas while sucking the gas from the suction chamber into the compression chamber and discharges the gas to the discharge chamber Applied to the machine.

  The feature of the configuration adopted by the invention of claim 1 is that the compression operation is stopped in the space formed by the discharge chamber of the low-pressure side compression unit, the intermediate flow path, and the suction chamber of the high-pressure side compression unit. In some cases, an orifice is provided to release the residual pressure remaining in the compression chamber on the high-pressure side to the outside.

  Moreover, according to invention of Claim 2, the said orifice is set as the structure provided in the suction chamber side of the said high voltage | pressure side compression part.

  On the other hand, according to the invention of claim 3, the orifice is provided on the discharge chamber side of the low-pressure side compression section.

  According to a fourth aspect of the invention, the orifice is configured to be provided in the intermediate flow path between the low pressure side compression portion and the high pressure side compression portion.

  Further, the invention of claim 5 is provided with a silencer means for reducing noise when the residual pressure is released from the orifice to the downstream side of the orifice.

  As described above, according to the first aspect of the present invention, the compressor is operated by providing the orifice in the space formed by the discharge chamber of the low pressure side compression unit, the intermediate flow path, and the suction chamber of the high pressure side compression unit. At the time of stop, the residual pressure in the compression chamber on the high pressure side can be released from the space to the outside through the orifice, and the load at the subsequent restart can be reduced. Even when compressed gas remains in the discharge chamber of the low-pressure side compression section, this residual gas can be released to the outside through the space and the orifice, and the starting load of the low-pressure side compression section can be reduced. Can do.

  Therefore, by simply providing an orifice in the space formed by the discharge chamber of the low-pressure side compression section, the intermediate flow path, and the suction chamber of the high-pressure side compression section, the load when restarting the compressor can be reliably reduced. The structure of the apparatus can be simplified to improve the workability during assembly. In addition, the commercial value as a multistage compressor can be increased, energy saving can be achieved, and reliability can be improved.

  According to the second aspect of the present invention, by providing an orifice on the suction chamber side of the high pressure side compression section, the residual pressure in the compression chamber is released from the suction chamber to the outside through the orifice when the operation of the compressor is stopped. It is possible to reduce the load during the subsequent restart. Even if compressed gas remains in the discharge chamber of the low-pressure side compression section, this residual gas can be released to the outside through the intermediate flow path, the high-pressure side suction chamber, and the orifice. The starting load can be reduced.

  On the other hand, in the invention according to claim 3, by providing an orifice on the discharge chamber side of the low pressure side compression section, when the operation of the compressor is stopped, the low pressure side compression is performed from the compression chamber of the high pressure side compression section via the intermediate flow path. The residual pressure flowing back to the discharge chamber of the part can be released to the outside through the orifice, and the load when the compressor is restarted can be surely reduced.

  The invention according to claim 4 provides an orifice in an intermediate flow path located between the low pressure side compression portion and the high pressure side compression portion, so that when the compressor is stopped, the compression chamber of the high pressure side compression portion is removed. The residual pressure flowing back into the intermediate flow path can be released to the outside through the orifice, and the load when the compressor is restarted can be surely reduced.

  Further, according to the invention described in claim 5, since the noise reduction means for noise reduction is provided on the downstream side of the orifice, the exhaust noise is released when the above-mentioned residual pressure or the like is released to the outside through the orifice. Therefore, the noise around the compressor can be reliably reduced, the commercial value of the multistage compressor can be increased, and the reliability can be improved.

  Hereinafter, a case where the multistage compressor according to the embodiment of the present invention is applied to a two-stage reciprocating air compressor will be described as an example and described in detail with reference to the accompanying drawings.

  Here, FIG. 1 to FIG. 3 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a crankcase which is a main part of a reciprocating air compressor. A crankshaft 2 is rotatably provided in the crankcase 1 via a bearing or the like. The crankshaft 2 has one end protruding to the outside of the crankcase 1, and the protruding end is connected to a drive source (not shown) such as an electric motor.

  Reference numeral 3 denotes a low pressure side compression portion provided on the crankcase 1, and the low pressure side compression portion 3 includes a cylinder 4, a valve plate 5, a piston 6, a compression chamber 7, a cylinder head 10, a suction chamber 12, and a discharge chamber, which will be described later. 13 or the like.

  Reference numeral 4 denotes a low-pressure side cylinder serving as a cylinder of the low-pressure side compression section 3, and the cylinder 4 is mounted on the crankcase 1 in an inclined state as shown in FIG. A cylinder head 10 described later is mounted on the cylinder 4 via a valve plate 5 as a valve seat member. Further, the valve plate 5 is provided with a suction hole 5A and a discharge hole 5B as shown in FIG.

  Reference numeral 6 denotes a piston as a movable partition wall provided in the cylinder 4 so as to be able to reciprocate. The piston 6 is slidably inserted into the cylinder 4 and is compressed between the valve plate 5 and the compression chamber 7 on the low pressure side. Is defined. The piston 6 is connected to the crankshaft 2 via a connecting rod 8 and a bearing 9 as shown in FIG. 1, and reciprocates in the cylinder 4 as the crankshaft 2 rotates.

  Reference numeral 10 denotes a low-pressure side cylinder head mounted on the cylinder 4 via the valve plate 5. The cylinder head 10 is provided with a suction port 10A and a discharge port 10B as shown in FIG. The cylinder head 10 is provided with a partition wall 11 serving as a partition plate between the valve plate 5 and the partition wall 11 communicating with the suction chamber 12 and the discharge port 10B communicating with the suction port 10A in the cylinder head 10. The discharge chamber 13 is defined as two chambers.

  Reference numeral 14 denotes a suction valve provided in the valve plate 5 for opening and closing the suction hole 5A. The suction valve 14 communicates and blocks the compression chamber 7 and the suction chamber 12 through the suction hole 5A. A discharge valve 15 is provided in the valve plate 5 to open and close the discharge hole 5B. The discharge valve 15 communicates and blocks the compression chamber 7 and the discharge chamber 13 through the discharge hole 5B.

  Reference numeral 16 denotes a high pressure side compression portion provided on the crankcase 1, and the high pressure side compression portion 16 includes a cylinder 17, a valve plate 18, a piston 19, a compression chamber 20, a cylinder head 22, a suction chamber 23, and a discharge chamber, which will be described later. 24 and the like. The low pressure side compression unit 3 and the high pressure side compression unit 16 are mounted on the crankcase 1 in a substantially V shape as shown in FIG.

  Reference numeral 17 denotes a high-pressure side cylinder that serves as a cylinder of the high-pressure side compression section 16, and this cylinder 17 is attached to the crankcase 1 in an inclined state as shown in FIG. 1. A cylinder head 22 described later is mounted on the cylinder 17 via a valve plate 18 as a valve seat member. Further, the valve plate 18 is provided with a suction hole 18A and a discharge hole 18B as shown in FIG.

  Reference numeral 19 denotes a piston as a movable partition wall provided in the high-pressure side cylinder 17 so as to be able to reciprocate. The piston 19 is slidably inserted into the cylinder 17 and is located between the valve plate 18 and the high-pressure side. A compression chamber 20 is defined. The piston 19 is connected to the crankshaft 2 via a connecting rod 21 as shown in FIG. 1 and reciprocates in the cylinder 17 as the crankshaft 2 rotates.

  Reference numeral 22 denotes a high-pressure side cylinder head mounted on the cylinder 17 via the valve plate 18. The cylinder head 22 is provided with a suction port 22A and a discharge port 22B as shown in FIG. The cylinder head 22 is defined by a partition wall 27 described later in two chambers, a suction chamber 23 communicating with the suction port 22A and a discharge chamber 24 communicating with the discharge port 22B.

  Reference numeral 25 denotes a suction valve provided on the suction hole 18A side of the valve plate 18. The suction valve 25 communicates and blocks the suction chamber 23 and the compression chamber 20 through the suction hole 18A. A discharge valve 26 is provided on the discharge hole 18B side of the valve plate 18. The discharge valve 26 communicates and blocks the compression chamber 20 and the discharge chamber 24 through the discharge hole 18B.

  In this case, the suction valve 25 opens the suction hole 18A of the valve plate 18 in the suction stroke of the piston 19 that reciprocates in the cylinder 17, and closes the suction hole 18A in the discharge stroke. When the discharge stroke is completed (including when the piston 19 is stopped), a small gap (not shown) is generated between the suction valve 25 and the valve plate 18, and the suction chamber 23 and the compression chamber 20 are passed through this gap. Can communicate.

  Reference numeral 27 denotes a partition wall provided in the cylinder head 22, and the partition wall 27 defines a suction chamber 23 and a discharge chamber 24 in the cylinder head 22 between the valve plate 18 as shown in FIGS. 2 and 3. Yes. For example, a circular or quadrangular space portion 27A is formed inside the partition wall 27. The space portion 27A communicates with the outside (outside air) of the cylinder head 22 through an exhaust hole 29 described later.

  An orifice 28 is provided on the suction chamber 23 side of the high-pressure side compression section 16, and the orifice 28 is a small hole formed in the partition wall 27, and the suction chamber 23 flows into the space portion 27 </ b> A in the partition wall 27. It communicates with the road area. The orifice 28 is a small gap (not shown) generated between the suction valve 25 and the valve plate 18, and the suction hole 18 </ b> A of the valve plate 18 and the suction chamber. 3 through the space portion 27A in the direction of arrow A in FIG.

  Reference numeral 29 denotes a small-diameter exhaust hole that allows the space 27A in the partition wall 27 to communicate with the outside of the cylinder head 22. The exhaust hole 29 is a small hole formed on the upper surface side of the cylinder head 22, and the residual pressure is reduced. It is discharged from the space 27A of the partition wall 27 in the direction indicated by the arrow B in FIG.

  Reference numeral 30 denotes a silencing filter provided in the space 27A of the partition wall 27. The silencing filter 30 is formed using, for example, a nonwoven fabric, an open-cell porous material, or the like. ) Is allowed to circulate. The noise reduction filter 30 constitutes a noise reduction means as a noise reduction silencer together with the space portion 27A and the exhaust hole 29.

  That is, the muffler filter 30 is disposed at a position on the downstream side of the residual pressure flowing through the orifice 28. Then, the residual pressure flows from the orifice 28 into the space 27A in the direction of arrow A in FIG. 3, and after gradually passing through the muffler filter 30, the residual pressure passes through the exhaust hole 29 as indicated by the arrow B in FIG. Exhausted in the direction. At this time, the exhaust noise of the residual pressure is suppressed to a small level by the silencing action of the space 27 </ b> A in the partition wall 27, the silencing filter 30 and the exhaust hole 29.

  31 is an intermediate pipe as an intermediate flow path provided between the low-pressure side compression section 3 and the high-pressure side compression section 16, and the intermediate pipe 31 is connected at one end side to the discharge port 10B of the low-pressure side compression section 3, The other end side is connected to the suction port 22 </ b> A of the high-pressure side compression unit 16.

  Reference numeral 32 denotes a discharge pipe for connecting the discharge port 22B of the high pressure side compression unit 16 to an external storage tank (hereinafter referred to as an air tank 33). The discharge pipe 32 is a high pressure (for example, 2.. Compressed air compressed to about 6 to 3.0 MPa is discharged from the discharge chamber 24 and the discharge port 22B toward the air tank 33.

  The two-stage reciprocating air compressor according to the present embodiment has the above-described configuration. Next, the operation thereof will be described.

  First, when the crankshaft 2 is rotationally driven by a drive source such as an electric motor, the piston 6 reciprocates up and down in the low pressure side cylinder 4, and the piston 19 rotates in the high pressure side cylinder 17. Reciprocates along with.

  As the piston 6 reciprocates, the low pressure side compression section 3 enters the compression chamber 7 from the suction port 10A of the cylinder head 10 through the suction chamber 12, the suction hole 5A of the valve plate 5, and the suction valve 14 (low pressure). This air is compressed in the compression chamber 7. The compressed air (compressed air of intermediate pressure) is discharged from the discharge port 10B into the intermediate pipe 31 through the discharge hole 5B and the discharge chamber 13 while the discharge valve 15 is opened.

  For this reason, compressed air of intermediate pressure from the low pressure side compression unit 3 is supplied from the suction port 22 </ b> A of the cylinder head 22 into the suction chamber 23 of the high pressure side compression unit 16 through the intermediate pipe 31. The high-pressure side compression unit 16 opens the suction valve 25 as the piston 19 reciprocates in the cylinder 17, so that compressed air of intermediate pressure is compressed from the suction chamber 23 through the suction hole 18 </ b> A. 20 flows in.

  At this time, in the compression chamber 20, air is compressed to a higher pressure as the piston 19 reciprocates, and this compressed air is discharged through the discharge hole 18 </ b> B and the discharge chamber 24 while opening the discharge valve 26. It is discharged from the port 22B to the discharge pipe 32 and stored in the air tank 33.

  And the pressure rises by storing compressed air in the air tank 33, and when the pressure in the air tank 33 reaches an upper limit (for example, about 3.0 MPa), the compression operation by the electric motor is stopped, By maintaining the stop state until a lower limit value described later is reached, the durability and life of the compressor are increased, and labor saving and the like are achieved.

  In this case, the compressed air in the air tank 33 is appropriately used and consumed by pneumatic equipment such as a pneumatic cylinder and an air motor. And when the pressure in the air tank 33 falls to a lower limit (for example, about 2.6 MPa), the compression operation by the electric motor is resumed.

  By the way, when the operation of the compressor is stopped, for example, the compressed air often remains as a residual pressure in the compression chamber 20 of the high-pressure side compression unit 16, for example. As long as the residual pressure is not released to the outside, a load due to the residual pressure is generated when the compressor is restarted (restarted), and the starting load cannot be reduced.

  Therefore, according to the present embodiment, a hollow space portion 27A is formed in the partition wall 27 that defines the suction chamber 23 and the discharge chamber 24 in the cylinder head 22 between the valve plate 18 and the space portion. A small-diameter orifice 28 that allows the inside of 27A to communicate with the suction chamber 23 is provided.

  In addition, a silencer filter 30 is provided in the space 27A of the partition wall 27, and a small-diameter exhaust hole 29 that is located downstream of the orifice 28 and is always in communication with the space 27A is provided on the upper surface side of the cylinder head 22. It is set as the structure to provide.

  Thereby, when the compression operation is stopped, the compressed air remaining as the residual pressure in the compression chamber 20 of the high-pressure side compression unit 16 is a small gap (not shown) generated between the valve plate 18 and the suction valve 25. 3 gradually leaks from the suction hole 18A of the valve plate 18 into the suction chamber 23, and is discharged from the orifice 28 into the space 27A and the muffler filter 30 in the direction of arrow A in FIG.

  The residual pressure at this time is once exhausted from the orifice 28 into the space 27A of the partition wall 27 and the muffler filter 30, and then gradually exhausted from the exhaust hole 29 to the outside of the cylinder head 22. At the time of stop, the suction chamber 23 in the cylinder head 22 can be kept in a pressure state close to atmospheric pressure, and the compression chamber 20 in the cylinder 17 can be similarly kept at a low pressure.

  Further, the space 27A, the muffler filter 30 and the exhaust hole 29 of the partition wall 27 constitute a silencer (silencer) for reducing noise, and the residual pressure described above is externally supplied from the exhaust hole 29 via the orifice 28 and the space 27A. Therefore, it is possible to suppress the generation of abnormal noise due to exhaust sound or the like, and to reliably reduce noise around the compressor.

  Also, the discharge chamber 13 of the low-pressure side compressor 3 is always in communication with the high-pressure side suction chamber 23 via the intermediate pipe 31 as shown in FIG. As with the chamber 23, the pressure can be reduced.

  For this reason, when the compressor is restarted from the stopped state, the piston 19 can be smoothly driven in the high pressure side cylinder 17 without being affected by the residual pressure, and the starting load can be surely reduced. it can. In addition, since the discharge chamber 13 is in a low pressure in the low pressure side cylinder 4 as well, the piston 6 can be driven smoothly and the starting load can be kept small.

  Therefore, according to the present embodiment, it is possible to reduce the load at the time of restart only by providing the hollow space 27A, the orifice 28, the exhaust hole 29, and the like in the partition wall 27 of the cylinder head 22. It is possible to simplify the structure and improve workability during assembly.

  Since the orifice 28 is provided on the suction chamber 23 side, the orifice 28 does not adversely affect the piston 19 that slides in the cylinder 17, and the piston 19 can slide smoothly in the cylinder 17. For example, the durability and life of the piston ring or the like can be extended. That is, in the configuration in which the orifice is provided near the bottom dead center of the high pressure side cylinder, the piston ring may be damaged or broken when the orifice touches the piston ring or the like. In this case, damage to the piston ring can be eliminated.

  Further, the noise reduction filter 30 is provided in the space portion 27A of the partition wall 27, and the exhaust hole 29 provided in the cylinder head 22 constitutes a noise reduction means together with the space portion 27A and the noise reduction filter 30 in the partition wall 27. Exhaust sound such as residual pressure flowing out in the direction of arrow B in FIG. 3 from within 27A can be suppressed to a low level, increasing the commercial value as a multistage compressor and improving reliability.

  Next, FIG. 4 and FIG. 5 show a second embodiment of the present invention, and the feature of this embodiment is that an orifice for releasing the residual pressure is provided on the discharge chamber side of the low-pressure side compression section. There is. 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 the figure, reference numeral 41 denotes a low-pressure side compression section provided on the crankcase 1, and the low-pressure side compression section 41 is configured in substantially the same manner as the low-pressure side compression section 3 described in the first embodiment. , Valve plate 5, piston 6, compression chamber 7, suction chamber 12, discharge chamber 13, and the like. However, the low-pressure side compression portion 41 is formed such that a later-described partition wall 43 of a cylinder head 42 has a different shape.

  Reference numeral 42 denotes a low-pressure side cylinder head mounted on the cylinder 4 via the valve plate 5. The cylinder head 42 is configured in the same manner as the cylinder head 10 described in the first embodiment, and has a suction port 42A. And a discharge port 42B. However, in this case, the cylinder head 42 has a partition wall 43 described later formed in a different shape.

  A partition wall 43 is provided in the cylinder head 42. The partition wall 43 defines the inside of the cylinder head 42 into a suction chamber 12 and a discharge chamber 13 in the same manner as the partition wall 11 described in the first embodiment. Yes. However, in this case, the partition wall 43 is formed with, for example, a circular or square space 43A, and the space 43A communicates with the outside (outside air) of the cylinder head 42 through an exhaust hole 45 described later. Is.

  Reference numeral 44 denotes an orifice provided on the discharge chamber 13 side of the low-pressure side compression section 41. The orifice 44 is a small hole formed in the partition wall 43, and the discharge chamber 13 flows into the space portion 43A in the partition wall 43 with a small flow. It communicates with the road area. The orifice 44 releases the residual pressure in the compression chamber 20 to the outside in substantially the same manner as the orifice 28 described in the first embodiment.

  In other words, the orifice 44 in this case is a small gap (not shown) generated between the suction valve 25 and the valve plate 18, the residual pressure generated in the compression chamber 20 on the high pressure side when the compression operation is stopped. 18 escapes in the space 43A in the direction of arrow C in FIG. 5 through the 18 suction holes 18A, the suction chamber 23, the intermediate pipe 31, and the discharge chamber 13.

  45 is a small-diameter exhaust hole that allows the space 43A in the partition wall 43 to communicate with the outside of the cylinder head 42. The exhaust hole 45 is a small hole formed on the upper surface side of the cylinder head 42, and the residual pressure is reduced. It is discharged from the space 43A of the partition wall 43 in the direction of arrow D in FIG.

  Reference numeral 46 denotes a silencing filter provided in the space 43A of the partition wall 43. The silencing filter 46 is configured in the same manner as the silencing filter 30 described in the first embodiment, and has a residual pressure (intermediate pressure). Compressed air) is allowed to circulate. The sound deadening filter 46 constitutes a sound deadening means as a noise reducing silencer together with the space 43A and the exhaust hole 45.

  Reference numeral 47 denotes a high-pressure side compression section provided on the crankcase 1. The high-pressure side compression section 47 is configured in substantially the same manner as the high-pressure side compression section 16 described in the first embodiment, and includes a cylinder 17 and a valve plate. 18, a piston 19, a compression chamber 20, a suction chamber 23, a discharge chamber 24, and the like. However, in the high-pressure side compression portion 47, a partition wall 49 of a cylinder head 48 described later is formed in a different shape.

  48 is a high-pressure cylinder head mounted on the cylinder 17 via the valve plate 18. The cylinder head 48 is configured in the same manner as the cylinder head 22 described in the first embodiment, and includes a suction port 48A and A discharge port 48B is provided. However, in this case, the cylinder head 48 has the partition walls 49 formed in different shapes. In other words, the partition wall 49 in this case is formed as a partition plate that defines the inside of the cylinder head 48 into two chambers of the suction chamber 23 and the discharge chamber 24.

  Thus, in the present embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment. In particular, in the present embodiment, the residual pressure generated in the compression chamber 20 on the high pressure side when the compression operation is stopped is used as a clearance between the suction valve 25 and the valve plate 18, the suction hole 18 </ b> A of the valve plate 18, and the suction chamber. 23, it can escape from the discharge chamber 13 on the low pressure side via the intermediate pipe 31 in the directions indicated by arrows C and D in FIG.

  Next, FIG. 6 shows a third embodiment of the present invention, and the feature of this embodiment is that an orifice for releasing the residual pressure is provided in the middle of the intermediate flow path. 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 the figure, reference numeral 51 denotes a high pressure side compression section provided on the crankcase 1, and the high pressure side compression section 51 is configured in substantially the same manner as the high pressure side compression section 16 described in the first embodiment, and the cylinder 17 , Valve plate 18, piston 19, compression chamber 20, suction chamber 23, discharge chamber 24, and the like. However, in the high-pressure side compression portion 51, a partition wall 53 of a cylinder head 52 described later is formed in a different shape.

  Reference numeral 52 denotes a high-pressure side cylinder head mounted on the cylinder 17 via the valve plate 18. The cylinder head 52 is configured in the same manner as the cylinder head 48 described in the second embodiment, and includes a suction port 52A and A discharge port 52B is provided. The cylinder head 52 is provided with a partition wall 53 as a partition plate that defines an interior of the suction chamber 23 and the discharge chamber 24 as two chambers.

  54 is an intermediate pipe as an intermediate flow path connected to the suction port 52A of the cylinder head 52. The intermediate pipe 54 is configured in substantially the same manner as the intermediate pipe 31 described in the first embodiment, and is compressed on the low pressure side. The discharge port 10 </ b> B (see FIG. 2) of the portion 3 is communicated with the suction port 52 </ b> A of the high-pressure side compression portion 51. However, the intermediate pipe 54 in this case is provided with a residual pressure relief device 55 to be described later in the middle.

  55 is a residual pressure relief device provided in the middle of the intermediate pipe 54. The residual pressure relief device 55 includes a joint member 57 provided in the middle of the intermediate pipe 54 and having an orifice 56, and an exhaust hole 58 described later. And a mute filter 59. The joint member 57 is formed with a space portion 57A that communicates with the intermediate pipe 54 through the orifice 56, and a sound deadening filter 59 described later is accommodated in the space portion 57A.

  Here, the orifice 56 is a small hole, and communicates the inside of the intermediate pipe 54 with the space 57A of the joint member 57 with a small flow area. As a result, the orifice 56 causes the residual pressure in the compression chamber 20 to be a small gap (not shown) between the suction valve 25 and the valve plate 18 in substantially the same manner as the orifice 28 described in the first embodiment. The valve plate 18 escapes into the space 57A of the joint member 57 through the suction hole 18A, the suction chamber 23, the intermediate pipe 54, and the like.

  58 is a small-diameter exhaust hole that allows the inside of the space portion 57A of the joint member 57 to communicate with the outside. The exhaust hole 58 is a small hole formed in the outer surface of the joint member 57, and the residual pressure is supplied to the joint member 57. Is discharged in the direction indicated by arrow E in FIG.

  59 is a silencing filter provided in the space 57A of the joint member 57, and the silencing filter 59 is configured in the same manner as the silencing filter 30 described in the first embodiment. Of compressed air). The sound deadening filter 59 constitutes a sound deadening means as a noise reducing silencer together with the space 57A and the exhaust hole 58.

  Thus, in the present embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment. In particular, in the present embodiment, the residual pressure generated in the compression chamber 20 on the high pressure side when the compression operation is stopped is used as a clearance between the suction valve 25 and the valve plate 18, the suction hole 18 </ b> A of the valve plate 18, and the suction chamber. 23, it can escape from the orifice 56 of the joint member 57 via the intermediate pipe 54 in the direction of arrow E in FIG.

  In the third embodiment, the case where the residual pressure relief device 55 having the orifice 56 and the like is provided in the middle of the intermediate pipe 54 serving as the intermediate flow path has been described as an example. However, the present invention is not limited to this. That is, the orifice employed in the present invention is any one of the spaces formed by the discharge chamber of the low pressure side compression section, the intermediate flow path, and the suction chamber of the high pressure side compression section communicating with each other ( In some cases, an orifice may be provided at a plurality of locations.

  In the second embodiment, the case where the exhaust hole 45 is formed on the upper surface side of the cylinder head 42 has been described as an example. However, in the present invention, instead, for example, a small-diameter vent hole 45 ′ is provided as shown by a two-dot chain line in FIG. 5, and the space portion 43 A in the partition wall 43 communicates with the suction chamber 12 by this vent hole 45 ′. (In other words, the exhaust hole 45 may be eliminated).

  In this case, it is not necessary to provide the silencing filter 46 or the like in the space 43A in the partition wall 43. For example, a silencing effect is achieved by a suction filter (not shown) provided on the suction port 42A side of the cylinder head 42, for example. Obtainable. Further, in this case, the residual pressure is caused to flow backward to the suction port 42A from the small-diameter vent hole 45 'indicated by a two-dot chain line in FIG. A reverse air flow can be generated by the residual pressure, and foreign matter or the like adhering to the suction filter can be removed by the reverse air flow.

  On the other hand, in the first embodiment, the case where the muffler filter 30 is accommodated and provided in the space portion 27A of the partition wall 27 has been described as an example. However, the present invention is not limited to this, and for example, the interior of the space 27A may be hollow, and the sound deadening means may be configured using a change in the flow path area between the space 27A and the exhaust hole 29. . This also applies to the second and third embodiments.

  In each of the above embodiments, a two-stage reciprocating air compressor has been described as an example of the multistage compressor. However, the present invention is not limited to this, and may be applied to a compressor having three or more stages, for example. In this case, for example, in a three-stage compressor, the second-stage compression section becomes the low-pressure-side compression section relative to the third-stage compression section that becomes the high-pressure-side compression section, and the second-stage compression section (high-pressure-side compression section). On the other hand, the first stage compression section is the low pressure side compression section.

  In addition, as described in claim 1, an orifice may be provided on the suction chamber side for these high-pressure side compression portions. In addition, as described in claim 3, an orifice may be provided on the discharge chamber side of the low pressure side compression section. This also applies to compressors having four or more stages.

  Furthermore, the present invention may be applied to, for example, a multistage reciprocating compressor using a locking piston, and may be applied to various multistage compressors such as a scroll compressor.

1 is a longitudinal sectional view showing a two-stage reciprocating air compressor according to a first embodiment of the present invention. It is principal part sectional drawing which shows the low voltage | pressure side compression part and high pressure side compression part in FIG. 1 with an air tank. It is a longitudinal cross-sectional view which expands and shows the high voltage | pressure side compression part in FIG. It is principal part sectional drawing which shows the low pressure side compression part and high pressure side compression part by 2nd Embodiment with an air tank. It is a longitudinal cross-sectional view which expands and shows the low voltage | pressure side compression part in FIG. It is sectional drawing which shows an intermediate | middle piping and a high voltage | pressure side compression part etc. with the residual pressure relief apparatus by 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crankcase 2 Crankshaft 3,41 Low pressure side compression part 4 Low pressure side cylinder 5,18 Valve plate 6,19 Piston 7,20 Compression chamber 10,42 Low pressure side cylinder head 11,43 Partition 12 Low pressure side suction chamber 13 Low pressure side discharge chamber 16, 47, 51 High pressure side compression section 17, 52 High pressure side cylinder 22, 48, 52 High pressure side cylinder head 23 High pressure side suction chamber 24 High pressure side discharge chamber 27, 49, 53 Partition 27A, 43A, 57A Space 28, 44, 56 Orifice 29, 45, 58 Exhaust hole 30, 46, 59 Silencer filter (silencer)
31, 54 Intermediate piping (intermediate flow path)
32 Discharge piping 33 Air tank (storage tank)
45 'Ventilation hole 55 Residual pressure relief device 56 Joint member

Claims (5)

A low-pressure side compression section that compresses the low-pressure gas while sucking it from the suction chamber into the compression chamber, and discharges the compressed gas to the discharge chamber;
A high-pressure side compression unit that has a suction chamber connected to a discharge chamber of the low-pressure side compression unit via an intermediate flow path, compresses the gas from the suction chamber into the compression chamber, and discharges the gas into the discharge chamber; In a multistage compressor comprising:
In the space formed by the discharge chamber of the low-pressure side compression unit, the intermediate flow path, and the suction chamber of the high-pressure side compression unit, the residual pressure remaining in the compression chamber on the high-pressure side when the compression operation is stopped A multistage compressor characterized in that a relief orifice is provided.   The multistage compressor according to claim 1, wherein the orifice is configured to be provided on a suction chamber side of the high-pressure side compression unit.   The multistage compressor according to claim 1, wherein the orifice is configured to be provided on a discharge chamber side of the low-pressure side compression unit.   The multistage compressor according to claim 1, wherein the orifice is configured to be provided in the intermediate flow path between the low pressure side compression unit and the high pressure side compression unit.   5. The multistage compressor according to claim 1, 2, 3, or 4, wherein a silencer for reducing a sound when the residual pressure is released from the orifice to the outside is provided on the downstream side of the orifice.

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