JP6082300B2 - Compressor air intake structure - Google Patents

Description

  The present invention relates to a structure of an intake section of a compressor, and more specifically, controls the intake air of a compressor body driven by a prime mover such as an engine or an electric motor so that the pressure of compressed gas supplied to a consumer side is a predetermined target. The present invention relates to an intake section structure of a compressor provided with a capacity control device that controls the pressure to approach the pressure.

  For a compressor that sucks and compresses gas into a compressor body driven by a prime mover and supplies compressed gas to the consumption side to which an air working machine or the like is connected, a compressor is used according to the secondary side pressure of the compressor body. A capacity control device for controlling the intake air amount of the main body is provided. By controlling the intake air amount of the compressor main body with this capacity control device, the control (capacity control) brings the secondary pressure of the compressor main body close to a predetermined target pressure. Control) to supply a compressed gas with a stable pressure to the consumer side.

  As an example, in the engine-driven oil-cooled screw compressor 100 shown in FIG. 5, a receiver tank 160 that stores compressed gas discharged from the compressor main body 140 is provided on the secondary side of the compressor main body 140 and the compression is performed. A normally open type capacity control valve 110 is constituted by a valve body 112 including a butterfly valve that opens and closes an intake port 143 of the machine main body 140 and a regulator 114 that controls the operation of the valve body 112, and the regulator of the capacity control valve 110 114 is connected to an introduction circuit 163 for introducing the compressed gas in the receiver tank 160 described above, and a pressure regulator 164 which is a pressure adjusting valve for opening and closing the introduction circuit 163 is provided, thereby constituting a capacity control device. .

  In the compressor 100 of FIG. 5 provided with the above capacity control device, when the pressure in the receiver tank 160 is less than the operation start pressure of the pressure regulator 164 and the introduction circuit 163 is closed, the regulator 114 of the capacity control valve 110 is connected. On the other hand, no compressed gas is introduced, and the valve body 112 of the capacity control valve 110 is in a state where the intake port 143 is opened by the biasing force of the return spring of the regulator 114.

  On the other hand, when the pressure in the receiver tank 160 becomes equal to or higher than the operation start pressure of the pressure regulator 164 and the introduction circuit 163 is opened, the compressed gas from the receiver tank 160 is introduced into the regulator 114 of the capacity control valve 110, and the capacity control valve 110 restricts the pressure of the receiver tank 160 to maintain a predetermined target pressure by restricting or closing the intake port 143 according to the pressure of the introduced compressed gas.

  Reference numeral 180 in FIG. 5 is an auto relief valve that operates using the secondary side pressure of the compressor main body 140 and the pressure in the receiver tank 160 as pilot pressures. The compressor main body 140 stops and the compressor main body 140 When the secondary pressure decreases below the pressure in the receiver tank 160, the air release circuit 166 is opened to release the compressed gas in the receiver tank 160.

  In the compressor configured as described above, when the compressor main body 140 is started with the intake port 143 opened, the compressor main body 140 generates a large load by sucking and compressing a large amount of gas. Since a large load is also applied to the prime mover 150 that drives the engine 150, a start-up congestion that causes the start-up of the prime mover 150 occurs, or the prime mover 150 that is in an unstable operation state at a low rotational speed immediately after the start is stopped. Such as starting failure occurs.

  Therefore, when the compressor 100 is started, the intake port 143 of the compressor body 140 is closed to prevent a large amount of gas from being sucked into the compressor body 140, thereby reducing the load applied to the prime mover 150. An apparatus 120 has been proposed.

  As such a starting load reducing device 120, in the compressor 100 of FIG. 5, a bypass circuit 122 that bypasses the pressure regulator 164 is provided in the introduction circuit 163, and a starting valve 121 that opens and closes the bypass circuit 122 is provided. ing.

  In this configuration, by manually operating the start valve 121 and opening the bypass circuit 122 before starting the compressor 100, the pressure in the receiver tank 160 is introduced into the regulator 114 of the capacity control valve 110 without passing through the pressure regulator 164. As a result, when the compressor body 140 starts discharging compressed gas and the pressure in the receiver tank 160 rises to the operation start pressure of the regulator 114 of the capacity control valve 110 by starting the compressor 100, the butterfly valve 112. As a result, the intake port 143 is closed, and the load applied to the prime mover 150 can be reduced thereafter.

  Then, after the compressor 100 is started and the prime mover 150 is in a stable operating state, the start valve 121 is manually operated again to close the bypass circuit 122, whereby the pressure in the receiver tank 160 is started to operate the pressure regulator 164. The intake port 143 of the compressor main body 140 is fully opened until the pressure reaches the pressure, and then the pressure of the compressed gas introduced into the regulator 114 of the capacity control valve 110 is increased when the pressure in the receiver tank 160 becomes equal to or higher than the operation start pressure of the pressure regulator 164. The capacity control is started so as to restrict or close the intake port 143 in accordance with the pressure.

  Further, as another configuration of the starting load reducing device, a butterfly valve that opens and closes the intake port of the compressor main body in the same manner as the compressor described with reference to FIG. 5 described above, and this butterfly valve is controlled by the pressure in the receiver tank. In a compressor equipped with a capacity control valve composed of a regulator that opens and closes, a solenoid for controlling the opening and closing of the butterfly valve in addition to the regulator is provided in the capacity control valve, and the solenoid is energized for a predetermined time immediately after starting. Thus, a starting load reducing device that maintains the butterfly valve in a closed state has also been proposed (FIGS. 1 and 7 of Patent Document 1).

  Similarly, in a compressor equipped with a capacity control valve composed of a butterfly valve and a regulator, the discharge port of the mini compressor is connected to the introduction circuit that connects the regulator of the capacity control valve and the receiver tank, and the compressor is started. It has also been proposed that the compressor can be started with the load reduced by operating the mini compressor in advance and closing the intake port with the butterfly valve. (See Patent Document 2).

  In the compressor 100 provided with the capacity control device having the above-described configuration, the check valve 144 is provided in the discharge circuit 141 that communicates the discharge port of the compressor main body 140 and the receiver tank 160, and the compressor main body 140 is stopped. At this time, it is necessary to prevent the compressed gas in the receiver tank 160 from flowing back to the compressor main body 140 (see FIG. 5, reference numeral 15 in FIG. 6 of Patent Document 1, and reference numeral 15 in FIG. 3 of Reference Document 2). reference).

  In addition, when the compressor main body 140 is oil-cooled, an oil supply circuit 142 for supplying lubricating oil collected in the receiver tank 160 to the working space of the compressor main body 140 is provided, and the pressure in the receiver tank 160 is increased. The lubricating oil collected in the receiver tank 160 can be supplied to the compressor main body 140, and the oil that opens the oil supply circuit 142 by using the secondary side pressure of the compressor main body 140 as the operating pressure in the oil supply circuit 142. A check valve 145 is provided so that the oil check valve 145 closes the oil supply circuit 142 when the compressor 100 is stopped when the secondary pressure of the compressor main body 140 is reduced. This prevents the lubricant oil from being suddenly introduced into the compressor main body 140 (see FIG. 5).

JP-A-9-242673 Utility Model Registration No. 3039941

  Of the starting load reducing devices described above, the starting load reducing device 120 described with reference to FIG. 5 requires manual operation of the starting valve 121 for each start, and is complicated.

  Moreover, in the configuration of the starting load reducing device 120 shown in FIG. 5, the intake port 143 remains open from the start of the prime mover 150 until the regulator 114 of the capacity control valve 110 is operated. Immediately after that, the load on the compressor main body 140 cannot be reduced.

  On the other hand, in the inventions described in Patent Documents 1 and 2, for example, solenoid excitation and mini-compressor start can be automated in conjunction with a start switch of the compressor body, which has been described with reference to FIG. This eliminates the complexity of manual operation such as the starting load reducing device 120, and further reduces the load on the compressor main body 140 at the time of starting and immediately after starting.

  However, in the configurations described in Patent Documents 1 and 2, since the blockage of the intake port of the compressor body depends on the solenoid and mini-compressor that operates when supplied with electric power, the engine is the engine at the start of the compressor. In some cases, the use of a cell motor causes a sudden voltage drop in the electric circuit. When the prime mover is an electric motor, a large starting current is required to start the motor, resulting in a sudden drop in the power supply voltage. If the supply voltage becomes unstable due to, for example, a solenoid or mini-compressor cannot keep the butterfly valve closed, the intake port opens and the starting load of the prime mover cannot be reduced sufficiently.

  In addition, in the configuration described in Patent Document 2, the intake port is not blocked from the start of the mini compressor until the compressed gas having a predetermined pressure is introduced into the regulator of the displacement control valve. If the prime mover is to be started with the valve closed, it is necessary to start the mini compressor in advance before starting the prime mover, and a predetermined waiting time is required before starting the prime mover.

  In the configuration including the capacity control valve 110 shown in FIG. 5, a check valve 144 is provided in the discharge circuit 141 from the compressor body 140 to the receiver tank 160, and an oil check valve 145 is provided in the oil supply circuit 142. The oil supply circuit 142 can be closed when the compressor 100 is stopped, and even if the pressure on the compressor main body 140 side is reduced due to the stop of the compressor main body 140, the high pressure in the receiver tank 160 is increased. The compressed gas and the lubricating oil are prevented from flowing into the compressor main body 140 abruptly.

  However, by adopting such a configuration in which the check valve 144 and the oil check valve 145 are provided in the circuit, the number of components of the compressor increases. Particularly, in the oil check valve 145, not only the oil check valve 145 is simply installed in the oil supply circuit 142, but also piping work such as connecting a pipe for obtaining a pilot pressure to the discharge circuit 141 is required. Such an increase in the number of parts and an increase in assembly man-hours increase the cost of the compressor 100.

  Moreover, even if the check valve 144 and the oil check valve 145 are provided to prevent the introduction of compressed gas or lubricating oil from the receiver tank 160, if the compressor main body 140 stops, the compressor main body 140 is compressed. Since the compressed gas in the middle suddenly expands, the backflow of the compressed gas and lubricating oil toward the intake port 143 side of the compressor body 140 cannot be completely prevented.

  In spite of the possibility of such a backflow, the compressor 100 described with reference to FIG. 5 and the configurations of the compressors described in the above-mentioned Patent Documents 1 and 2 can be used when the compressor 100 is stopped. Since the butterfly valve 112 of the capacity control valve 110 is in a state in which the intake port 143 is fully opened, the compressed gas or lubricating oil that has flowed back passes through the air filter 170 through the intake port 143 and the butterfly valve 112, and the compressor Even if the amount and momentum of the compressed gas and lubricating oil flowing back can be reduced by providing the check valve 144 and the oil check valve 145 described above, the lubricating oil for the air filter 170 may be blown out. It is not possible to completely prevent the adhesion of lubricant to the equipment housed in the soundproof box.

  In the configurations described in Patent Documents 1 and 2, if it is intended to prevent such a blow-out due to the backflow of compressed gas or lubricating oil, energization of the solenoid or mini-compressor is continued even when the compressor is stopped. Although it is conceivable to keep the intake port of the main unit closed, the use of such a configuration increases the power consumption of the device and is not economical, and when the power source of the device is a battery. Can also cause battery drain.

  Accordingly, the present invention has been made to solve the above-described disadvantages of the prior art, and even if a sudden voltage drop or the like occurs in an electric circuit at the start-up while having a relatively simple configuration. The compressor inlet can be reliably kept closed without being affected by the engine, and therefore the engine may start up with a traffic jam or start up before moving to stable operation. Compression that can prevent the compressed gas and lubricating oil from blowing out when the compressor is stopped even if the check valve is not installed in the discharge circuit or the oil check valve is installed in the oil supply circuit. An object of the present invention is to provide an air intake structure of a machine.

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

In order to achieve the above object, the intake section structure of the compressor 1 of the present invention includes an oil-cooled compressor body 40 driven by a prime mover 50 such as an engine or an electric motor, and the compressor body 40 together with lubricating oil. A receiver tank 60 for storing the discharged compressed gas, and capacity control for closing or closing the intake port 43 of the compressor body 40 when the pressure in the receiver tank 60 becomes equal to or higher than a predetermined capacity control start pressure. In a compressor having a normally open type capacity control valve 10,
A suction passage 30 communicating with the intake port 43 of the compressor main body 40 is provided, and the capacity control valve 10 is disposed in the suction passage 30, and the capacity control valve 10 is opened from the primary side to the secondary side when the valve is opened. A valve body 12 having a check function that allows only gas to pass through
An auxiliary oil supply circuit 65 for discharging the lubricating oil in the receiver tank 60 by internal pressure is communicated with the receiver tank 60;
A normally closed auxiliary open / close valve 20 is provided in the primary or secondary suction passage 30 of the capacity control valve 10, and the closed pressure receiving chamber 23 of the auxiliary open / close valve 20 communicates with the auxiliary oil supply circuit 65. In addition, the valve opening start pressure of the auxiliary on-off valve 20 is set to a predetermined normal operation start pressure lower than the capacity control start pressure (Claim 1).

  In the intake section structure of the compressor 1 having the above-described configuration, the oil supply circuit 42 that supplies the lubricating oil in the receiver tank 60 to the compressor main body 40 is branched, and the circuit obtained by the branch is the above-described auxiliary oil supply circuit 65. (Claim 2).

  Furthermore, after the compressor 1 is started, a minute communication path 39 that communicates the primary side and the secondary side of the auxiliary on-off valve 20 when the auxiliary on-off valve 20 closes the suction passage 30 is provided with a predetermined rotational speed (prime motor). Of the compressor main body 40 in which the pressure in the receiver tank 60 rises to the normal operation start pressure or higher after the engine speed rises to 50 or more, for example, the idle rotation speed when the prime mover is an engine. It can be formed in a flow passage area that generates an intake air amount.

  Alternatively, an open / close valve such as a solenoid valve (not shown) that opens the auxiliary oil supply circuit 65 when the operating state of the prime mover 50 becomes equal to or higher than a predetermined rotational speed (for example, idle rotational speed) that is stable may be provided ( Claim 4).

  According to the configuration of the present invention described above, according to the compressor 1 having the intake portion structure of the present invention, from the start of the compressor 1 until the pressure in the receiver tank 60 rises to a predetermined normal operation start pressure or higher. Alternatively, the intake air of the compressor main body 40 is increased until the pressure in the receiver tank 60 rises above a predetermined normal operation start pressure and the rotation speed of the prime mover rises above a predetermined rotation speed at which the operation state of the prime mover is stabilized. Since the opening 43 is closed by the auxiliary opening / closing valve 20, the compressor 1 is started in a state where the load is closed with the intake port 43 closed, although the capacity control valve 10 is open. I was able to.

  In addition, since the intake port 43 is closed by the normally closed auxiliary control valve 20, the use of the cell motor when starting the engine, which is the prime mover 50, or the starting motor, which is the prime mover, are started. Even when a large fluctuation occurs in the voltage in the electric circuit due to the input of the starting current, the intake port 43 can be reliably maintained in the closed state without being affected by this.

  On the other hand, when the compressor 1 is stopped, the compressed gas and lubricating oil in the receiver tank 60 suddenly flow into the compressor body 40 and pass through the intake port 43, the intake passage 30, the air filter 70, etc., and enter the soundproof box. Although it is going to blow out, compressed gas and lubricating oil do not flow backward beyond the capacity control valve 10 by providing the valve body 12 with a check function in the capacity control valve 10.

  As a result, unlike the conventional compressor configuration described with reference to FIG. 5, it is necessary to provide a check valve in the discharge circuit 41 for introducing the compressed gas discharged from the compressor body 40 into the receiver tank 60. In addition, there is no need to provide an oil check valve or its pilot circuit in the oil supply circuit 42 for supplying the lubricating oil collected in the receiver tank 60 to the compressor body 40, and compression is achieved by reducing the number of parts and the number of assembly steps. The manufacturing cost of the machine 1 could be reduced.

  In addition, since the lubricating oil supplied from the receiver tank 60 is used as the working fluid of the auxiliary on-off valve 20, the components of the auxiliary on-off valve 20 due to moisture in the compressed air that may occur when compressed air is used as the working fluid. It was possible to prevent the occurrence of malfunction due to rusting and freezing of condensed water when used in cold regions.

  In particular, when the compressor having the air intake structure of the present invention is used in a cold region, especially when the prime mover of the compressor is an engine, the prime mover is more than when used under a warm condition. It is difficult to start, and after the compressor starts, the time required to reach a stable operating state by warming the prime mover becomes longer.

  However, since the working fluid of the auxiliary on-off valve 20 is the lubricating oil in the receiver tank 60 as in the present application, the temperature of the lubricating oil is low and the viscosity is high immediately after starting. As a result, the starting pressure of the auxiliary on / off valve 20 automatically shifts to the high pressure side, and a favorable delay can be caused in the opening operation of the auxiliary on / off valve 20 without any particular adjustment. .

  The above-described auxiliary oil supply circuit 65 is formed by branching the oil supply circuit 42 for supplying the lubricant in the receiver tank 60 to the compressor body 40, so that the structure of the receiver tank 60 can be relatively easily changed. An auxiliary oil supply circuit 65 could be provided.

  Further, after the compressor 1 is started, a minute communication path 39 that communicates the primary side and the secondary side of the auxiliary on-off valve 20 when the auxiliary on-off valve 20 closes the suction passage 30 is provided with a predetermined rotational speed (for example, a motor). Of the compressor main body 40 in which the pressure in the receiver tank 60 rises to the normal operation start pressure or higher after the engine speed rises to 50 or more, for example, the idle rotation speed when the prime mover is an engine. By forming the flow passage area to generate the intake air amount, the auxiliary on-off valve 20 does not open the intake passage before the rotational speed of the prime mover increases, and the increase in the load torque of the compressor body 40 is suppressed. Thus, the prime mover 50 can be prevented from stopping.

  Similarly, when an opening / closing valve (not shown) such as an electromagnetic valve is provided that opens the auxiliary oil supply circuit 65 when the operating state of the prime mover becomes equal to or higher than a predetermined rotational speed (for example, idle rotational speed). However, the auxiliary on-off valve 20 can be prevented from opening the suction passage before the rotational speed of the prime mover increases.

Explanatory drawing of the compressor of this invention. The principal part sectional drawing of a capacity control valve and an auxiliary on-off valve part. It is an enlarged view of the valve body part of the auxiliary on-off valve, (a) is an example in which the valve body (butterfly valve) is in contact with the inner peripheral surface of the body without any gap when the valve is closed, and (b) is the valve body and the inner periphery of the body. An example in which a gap is provided. Explanatory drawing of the compressor of this invention which shows the modification of the attachment position of an auxiliary on-off valve. Schematic explanatory drawing of the conventional compressor.

  The compressor of the present invention will be described below with reference to the accompanying drawings.

[Compressor configuration]
Reference numeral 1 in FIG. 1 denotes a compressor according to the present invention. The compressor 1 is discharged from a compressor body 40, a prime mover 50 such as an engine or an electric motor that drives the compressor body 40, and the compressor body 40. A receiver tank 60 for storing the compressed gas, and after storing the compressed gas discharged from the compressor main body 40 in the receiver tank 60, air not shown through a supply circuit 62 communicated with the receiver tank 60. It can be supplied to a consumer side to which a work machine or the like is connected.

  The above-described compressor body 40 is an oil-cooled screw compressor that compresses a gas to be compressed together with lubricating oil for lubrication, cooling and sealing, and the lubricating oil is provided in the receiver tank 60 via a discharge circuit 41. Is provided with a separator 61 for separating the oil from the compressed gas introduced as a gas-liquid mixed fluid, and the lubricating oil recovered in the receiver tank 60 is supplied to the compressor body 40 again. A circuit 42 is provided.

  The body 3 having the suction passage 30 formed therein is attached to the intake port 43 of the compressor body 40 described above, and the suction passage 30 formed in the body 3 is opened and closed according to the pressure in the receiver tank 60. A capacity control valve 10 for controlling the capacity and an auxiliary opening / closing valve 20 for closing the suction passage 30 on the primary side or the secondary side (secondary side in FIG. 1) of the capacity control valve 10 when the compressor 1 is started. In the illustrated embodiment, the body 3 is a common valve box for the capacity control valve 10 and the auxiliary on-off valve 20.

  For convenience of explanation, as shown in FIG. 2, the suction passage 30 formed in the body 3 is divided into a primary part 31 of the capacity control valve 10 and a secondary part of the capacity control valve 10 (auxiliary switching). The description will be made by assigning different reference numerals to the primary part 32 of the valve 20 and the secondary part 33 of the auxiliary on-off valve 20.

  In this embodiment, the capacity control valve 10 is formed as a normally open type, and when the pressure in the receiver tank 60 becomes equal to or higher than a predetermined capacity control start pressure, the suction passage 30 starts to be throttled. When the pressure rises, the capacity control valve 10 is configured to be completely closed.

  When the valve is opened, the capacity control valve 10 allows a gas to pass from the primary side to the secondary side, but prevents a gas flow from the secondary side to the primary side, and has a check body 12 with a check function. Is provided.

  In the present embodiment, the piston valve type capacity control valve shown in FIG. 2 is employed as the capacity control valve 10 having such a check function.

  A piston valve type capacity control valve 10 shown in FIG. 2 is integrally formed in a body 3 that is a valve box, and compresses a portion 31 of a suction passage 30 corresponding to a primary side of a valve body 12 via an air filter 70. The compressor body is opened to the atmosphere in a soundproof box (not shown) of the machine 1 and the portion 32 of the suction passage 30 forming the secondary side is connected via a valve body (butterfly valve) 21 of the auxiliary on-off valve 20 described later. It communicates with 40 intake ports 43.

  The valve body 12 of the capacity control valve 10 has a mushroom shape including a valve shaft 12a and a disk-like flange 12b attached to one end of the valve shaft 12a. The suction passage 30 can be closed by pressing the portion against the valve seat 13 provided in the suction passage 30.

  A cylinder 35 that communicates with the suction passage 30 via a cylindrical sleeve 34 is provided in the body 3, and the valve shaft 12 a of the valve body 12 is connected to the cylinder 35 in the sleeve 34. It is inserted so that it can move forward and backward.

  On the other hand, the aforementioned cylinder 35 communicating with the suction passage 30 (the portion 32 of the suction passage 30) via the sleeve 34 has a piston shaft 14a and a disk-like flange 14b attached to one end of the piston shaft 14a. The provided piston 14 is accommodated, and the tip end portion of the piston shaft 14 a of the piston 14 is inserted into the sleeve 34 so as to be movable forward and backward toward the valve body 12.

  In the aforementioned cylinder 35, the piston 14 is urged by the piston spring 15 in a direction away from the valve body 12, and the retreat position is restricted by a cover 36 that closes the end of the cylinder 35.

  Further, a valve body biasing spring 16 is mounted between the tip of the valve shaft 12a and the tip of the piston shaft 14a so as to urge the two shafts away from each other with a relatively weak force. The flange 12 b of the valve body 12 is gently pressed against the valve seat 13 provided in the suction passage 30 by the biasing force of the valve body biasing spring 16.

  The above-described cover 36 is provided with an inlet 36a and an outlet 36b, and operating pressure can be introduced into the pressure receiving chamber 37 formed between the cover 36 and the flange 14b of the piston 14 via the inlet 36a. In addition, the operating pressure in the pressure receiving chamber 37 can be released through the outlet 36b.

  2 is an escape passage formed in the valve shaft 12a of the valve body 12. When the distance between the piston shaft 14a and the valve shaft 12a is changed by the escape passage 12c, the end of both shafts is indicated. By allowing the gas in the suction passage 30 to be sucked and exhausted at an interval, the valve body 12 and the piston 14 are smoothly moved forward and backward.

  In the capacity control valve 10 configured as described above, the flange 12b of the valve body 12 is gently pressed against the valve seat 13 when the compressed gas is not introduced into the pressure receiving chamber 37. Therefore, when the pressure on the secondary side becomes lower than the pressure on the primary side of the valve body 12, the flange 12b of the valve body 12 is separated from the valve seat 13 to allow the passage of gas. Even in the valve state, when the gas tries to flow backward from the secondary side to the primary side of the valve body 12, the flange 12 b of the valve body 12 is pressed against the valve seat 13 to close the suction passage 30. Is blocked.

  When the capacity control valve 10 thus configured is closed, a compressed gas is introduced into the pressure receiving chamber 37 to resist the biasing force of the piston spring 15 and the valve body biasing spring 16. When the piston 14 is slid to the valve body 12 side, the tip end of the piston shaft 14a abuts on the tip end of the valve shaft 12a, and the flange 12b of the valve body 12 cannot be separated from the valve seat 13, so that the suction passage 30 is opened. Completely occluded.

  In this embodiment provided with such a capacity control valve 10, as shown in FIG. 1, an inlet 36a provided in the cover 36 is replaced with a capacity control introduction circuit 63 provided with a pressure regulator 64 which is a pressure regulating valve. The outlet 36b is opened to the atmosphere via a relief circuit 71 having a throttle 72 (in the illustrated example, the atmosphere is opened via the air filter 70).

  Therefore, in a state where the auxiliary opening / closing valve 20 described later shifts to a normal operation in which the suction passage 30 is opened, the introduction of the compressed gas to the capacity control valve 10 is not performed when the pressure in the receiver tank 60 is lower than the operating pressure of the pressure regulator 64. The intake passage 30 is open and outside air is sucked into the compressor body 40.

  On the other hand, when the pressure in the receiver tank 60 becomes equal to or higher than the capacity control start pressure that is the operating pressure of the pressure regulator 64 and the introduction of compressed gas into the pressure receiving chamber 37 of the capacity control valve 10 is started, the pressure introduced into the pressure receiving chamber 37 is increased. Accordingly, when the piston 14 moves forward to limit the movement range of the valve body 12 and the pressure in the receiver tank 60 rises, the tip of the piston shaft 14a of the piston 14 becomes the tip of the valve shaft 12a of the valve body 12. The flange 12b of the valve body 12 cannot be separated from the valve seat 13, and the suction passage 30 is completely blocked.

  As described above, in the present invention, the valve body 12 of the capacity control valve 10 is provided with a check valve function that allows only the gas flow from the primary side to the secondary side when the valve is opened. It is no longer necessary to provide both the check valve of the discharge circuit and the oil check valve of the oil supply circuit, which are indispensable in the circuit configuration of the conventional compressor described above.

  On the primary side or the secondary side (secondary side in the example shown in FIGS. 1 and 2) of the capacity control valve 10 configured as described above, a normally closed auxiliary opening / closing valve 20 for controlling the opening and closing of the suction passage 30 is provided. Is further provided.

  In the embodiment shown in FIGS. 1 and 2, the auxiliary opening / closing valve 20 is formed by a combination of a butterfly valve 21 that is a valve body and a piston type regulator 22 that opens and closes the butterfly valve 21.

  This piston type regulator 22 accommodates a piston 28 in a state of being urged by a return spring 24 in a cylinder formed in the regulator body, and includes a rod 27 for connecting the piston 28 and the butterfly valve 21. The O-ring fitted in the groove formed on the outer periphery of the piston 28 seals the inner periphery of the cylinder and the outer periphery of the piston 28 to isolate the valve-closing pressure receiving chamber 23 from the spring chamber. When the internal pressure rises and the piston 28 moves against the urging force of the return spring 24, the butterfly valve 21 opens according to the protruding length of the rod 27 that moves forward and backward together with the piston 28. The valve 21 is normally biased in the closing direction by a return spring 24 provided in the regulator 22. It has been.

  Such an operation of the piston 28 of the regulator 22 is performed by introducing lubricating oil in the receiver tank 60 into the valve-closing pressure receiving chamber 23 of the regulator 22. In the illustrated embodiment, the receiver tank 60 An auxiliary oil supply circuit 65 formed by branching an oil supply circuit 42 for supplying the recovered lubricating oil to the compressor body 40 is provided, and the auxiliary oil supply circuit 65 is communicated with the valve closing pressure receiving chamber 23 of the regulator 22. When the pressure in the receiver tank 60 rises above a predetermined normal operation start pressure, which is lower than the above-described capacity control start pressure, the biasing force of the return spring 24 by the pressure of the lubricating oil introduced into the valve closing pressure receiving chamber 23 The regulator 22 starts to operate against this, and then the opening degree of the butterfly valve 21 is increased in accordance with the increase in pressure, and eventually it is fully opened. To have.

  In the illustrated embodiment, the lubricating oil in the receiver tank 60 is introduced into the valve closing pressure receiving chamber 23 of the regulator 22 through the auxiliary oiling circuit 65 formed by branching the oiling circuit 42 as described above. However, the present invention is not limited to this configuration. One end of the auxiliary oil supply circuit 65 provided independently of the oil supply circuit 42 is communicated with the receiver tank 60 at the oil reservoir position, and the other end is connected to the regulator 22. You may communicate.

  In the embodiment shown in FIG. 2, the auxiliary opening / closing valve 20 is the same as the capacity control valve 10 in which the body 3 is a valve box, and the capacity control is performed in the suction passage 30 formed in the body 3. The above-described butterfly valve 21 is provided in the secondary portion 32 of the valve 10, and the regulator 22 is attached to the bracket 38 formed in the body 3.

  1 and 2, the auxiliary on-off valve 20 is provided on the secondary side of the capacity control valve 10, but the auxiliary on-off valve 20 is provided on the primary side of the capacity control valve 10 as shown in FIG. It may be provided.

  In the configuration example shown in FIG. 2, the support shaft 25 of the butterfly valve 21 is rotatably supported in a shaft hole (not shown) provided in the body 3 described above, and the support shaft is passed through the body 3. 25, the lever 26 is attached to the support shaft 25 protruding outside the body, and the rod 27 provided on the regulator 22 is connected to the lever 26, so that the rod 27 of the regulator 22 moves forward and backward. Accordingly, the butterfly valve 21 can be opened and closed.

  When the butterfly valve 21 is closed, the space on the primary side and the secondary side of the butterfly valve 21 is slightly communicated with each other by a minute communication path 39. Such a minute communication path 39 is shown in FIG. As shown, a through-hole is formed in the body 3 or the butterfly valve 21 while adopting a configuration in which no gap is formed between the outer edge of the butterfly valve 21 and the inner wall of the body 3 when the auxiliary on-off valve 20 is closed, or A pipe (not shown) that communicates both spaces may be provided to form the above-described minute communication passage 39, or when the butterfly valve 21 is fully closed as shown in FIG. It is also possible to form a slight gap δ between the outer periphery of the body 3 and the inner wall of the body 3, and this gap δ may be used as the above-described minute communication path 39.

  The amount of gas sucked into the compressor main body 40 through the above-described micro communication path 39 in a state where the butterfly valve 21 is closed, that is, the flow area of the micro communication path 39 is determined by the motor 50 driving the compressor main body 40. It can be experimentally determined according to the rising state of the rotational speed.

  Here, after the start of the prime mover 50, if the amount of gas sucked by the compressor main body 40 is large, the secondary pressure of the compressor main body 40 increases rapidly, so that the compressor main body 40 can be Since the load torque increases, the increase in the rotational speed of the prime mover becomes dull, and malfunctions such as starting congestion and stoppage of the prime mover can occur.

  On the contrary, if the amount of outside air sucked into the compressor body 40 is zero or close to the state after the prime mover 50 is started, the power required to drive the compressor body 40 can be kept low. Therefore, although it is possible to avoid start-up congestion and stoppage of the prime mover, oil supply to the compressor body is performed using the pressure in the receiver tank 60, so there is a possibility that insufficient oil supply to each part of the compressor body 40 may occur. From the above viewpoint, it is preferable to form the minute communication passage 39 described above with a flow passage area capable of generating an appropriate intake amount.

  The determination of the intake air amount is such that the pressure in the receiver tank 60 becomes the normal operation start pressure after the compressor 1 is started up to a predetermined rotational speed or more at which the operation state of the prime mover is stabilized. 39 channel areas are determined.

  The valve closing pressure receiving chamber 23 of the regulator 22 of the auxiliary opening / closing valve 20 configured as described above is connected to the receiver tank 60 via the auxiliary oil supply circuit 65 and the oil supply circuit 42 as shown in FIG. When the internal pressure rises above the operation start pressure of the regulator 22, the piston 28 of the regulator 22 starts to move against the urging force of the return spring 24 according to the pressure of the lubricating oil introduced from the receiver tank 60. When the movement of the piston 28 moves the butterfly valve 21 via the rod 27 and the butterfly valve 21 starts to open the suction passage 30 and rises above a predetermined normal operation start pressure, the regulator 22 fully opens the butterfly valve 21. The intake control by the auxiliary opening / closing valve 20 is finished, and the capacity control is performed only by the capacity control valve 10 described above. And the like are performed.

  In the embodiment shown in FIGS. 1 and 2, the operation start pressure of the auxiliary on-off valve 20 is determined by the urging force of the return spring 24 provided in the regulator 22. In addition to the return spring 24, an auxiliary spring (not shown) that biases the butterfly valve 21 in the closing direction is provided. The sum of the biasing force of the return spring 24 and the biasing force of the auxiliary spring biases the butterfly valve 21 in the closing direction. It is good to do.

  In the configuration in which the auxiliary spring is provided in this way, a tension adjusting screw (not shown) attached to the auxiliary spring is attached by attaching / detaching the auxiliary spring or by replacing the auxiliary spring with one having a different urging force. By changing the tension of the auxiliary spring, the urging force for urging the butterfly valve 21 to the closed position may be changed, thereby changing the operation start pressure of the auxiliary on-off valve 20. By adjusting, the normal operation start pressure setting can be changed, and the time from the start of the compressor 1 to the start of capacity control can be changed in response to changes in the operating environment of the compressor 1, etc. It becomes.

  In the above description of the embodiment, the configuration in which the operation start of the auxiliary on-off valve 20 operates only in response to the increase in the pressure in the receiver tank 60 has been described. However, after the compressor 1 is started, the operation of the prime mover 50 is performed. It is preferable that the auxiliary opening / closing valve 20 is configured to start opening the suction passage 30 when the state becomes equal to or higher than a predetermined rotational speed.

  As described above, as described above, when the prime mover 50 reaches a predetermined rotational speed or higher, the opening operation of the auxiliary on-off valve 20 is relatively small as described above. By narrowing the pressure and increasing the pressure in the receiver tank 60 at the time of starting gradually, the rotational speed of the prime mover rises to the predetermined rotational speed, and then the pressure in the receiver tank 60 is delayed. For example, the auxiliary oil supply circuit 65 may be provided with an open / close valve such as an electromagnetic valve, and the rotation of the prime mover 50 measured by a tachometer or the like may be used. When the speed is less than a predetermined rotational speed, the auxiliary on-off valve 20 may be configured to maintain the closed state regardless of the pressure in the receiver tank 60.

  In the case where the compressor 1 is of a variable speed control type that controls the rotational speed of the prime mover 50 so that the pressure in the receiver tank 60 approaches the target pressure, the above-described predetermined rotational speed is variable. It may be set as a rotational speed that is equal to or higher than the lower limit rotational speed in the speed control range and lower than the upper limit rotational speed in the variable speed control range. For example, the pressure in the receiver tank 60 reaches the target pressure, and the capacity control valve It may be set to the same speed as the unload rotational speed that is the rotational speed of the prime mover 50 when the ten valve bodies 12 are completely closed.

  1 is an auto relief valve in which the secondary pressure of the displacement control valve 10 is a pilot pressure. The auto relief valve 80 is provided in an air discharge circuit 66 communicated with the receiver tank 60. The air release circuit 66 is opened by the increase of the secondary pressure of the capacity control valve 10 accompanying the stop of the compressor body so that the compressed gas in the receiver tank 60 can be released.

[Compressor operation, etc.]
1 to 4 show the state of each part of the compressor 1 in a stopped state.

  When the prime mover 50 is started from this state and the compressor main body 40 is rotated, the compressor main body 40 attempts to take in air from the air inlet 43, but the suction passage 30 communicated with the air inlet 43 of the compressor main body 40 is Since the auxiliary valve 20 is closed by the butterfly valve 21, only a small amount of gas allowed by the minute communication passage 39 shown in FIGS. 3A and 3B can be sucked. As a result, the load is reduced. The compressor can be started in a reduced state.

  The flange 12b provided on the valve body 12 of the capacity control valve 10 is in a state where the pressure in the receiver tank 60 is low, and therefore even when the compressed gas is not introduced into the pressure receiving chamber 37 of the capacity control valve 10 at the time of valve opening. Although it is in contact with the valve seat 13, this contact is a gentle contact by the valve body biasing spring 16 and restricts the passage of gas from the primary side to the secondary side of the capacity control valve 10. Not.

  Therefore, when the suction by the compressor body 40 is started through the minute communication passage 39 described above, and the portion 32 of the suction passage 30 on the secondary side of the valve body 12 becomes negative due to this suction, the capacity control valve 10 The valve body 12 is separated from the valve seat 13 and the outside air is slightly sucked.

  Thus, immediately after the prime mover 50 is started, the butterfly valve 21 of the auxiliary on-off valve 20 closes the suction passage 30 and the amount of outside air sucked into the compressor body 40 is greatly restricted. Since the rise in the discharge side pressure (pressure in the receiver tank 60) becomes extremely gradual, the rise in the load torque of the compressor main body 40 also becomes gradual and is in a state immediately after starting, and the rotational speed is still low and unstable. The increase in the load applied to the prime mover 50 in the operating state can be moderated.

  As a result, by appropriately setting the flow passage area of the micro communication passage 39, the auxiliary on-off valve 20 is closed to the rotational speed at which the prime mover 50 is in a stable operation state, thereby reducing the load torque of the compressor main body 40. In this case, it is possible to suitably prevent the start-up congestion and the stoppage of the prime mover 50 from being suppressed, while the fuel supply to the compressor body 40 is performed using the pressure in the receiver tank 60. However, refueling can be performed appropriately.

  As described above, when the pressure in the receiver tank 60 gradually increases, the pressure of the lubricating oil introduced into the regulator 22 of the auxiliary on-off valve 20 also gradually increases, and when this pressure exceeds the operating pressure of the regulator 22. The regulator 22 increases the opening of the butterfly valve 21 as the pressure in the receiver tank 60 increases.

  When the pressure in the receiver tank 60 further rises to a predetermined normal operation start pressure, the auxiliary opening / closing valve 20 opens the suction passage 30 and the intake control by the auxiliary control valve 20 is finished.

  Thereby, the intake control of the compressor body 40 is performed in the capacity control valve 10, the capacity control introduction circuit 63 that connects the pressure receiving chamber 37 of the capacity control valve 10 and the receiver tank 60, and the capacity control introduction circuit 63. The process shifts to a known capacity control performed only by a capacity control device constituted by the provided pressure regulator 64.

Stop control When the prime mover 50 of the compressor 1 that has been operated as described above is stopped, the compressor main body 40 also stops rotating, so that the compression in the receiver tank 60 provided on the secondary side of the compressor main body 40 is stopped. The gas and the lubricating oil try to flow suddenly toward the compressor body 40 and its primary side.

  However, as described above, in the compressor 1 of the present invention, since the valve body 12 of the capacity control valve 10 has a check function, the compressed gas or the lubricating oil flows in this way, so that the capacity control valve 10 When the pressure on the secondary side rises, the flange 12b provided on the valve body 12 of the capacity control valve 10 is pressed against the valve seat 13 to close the suction passage 30, so that the compressed gas or lubricating oil is passed over the capacity control valve 10. Therefore, the lubricating oil does not blow out into the soundproof box through the air filter 70 and the air filter 70 and the components of the compressor 1 are not contaminated.

  Further, by providing the valve body 12 of the capacity control valve 10 with the check function in this way, the compressor 1 of the present invention differs from the conventional compressor described with reference to FIG. It is not necessary to provide a check valve in 41, and it is not necessary to provide an oil check valve in the oil supply circuit.

  On the other hand, when the compressor main body 40 is stopped, the compressed gas and lubricating oil in the receiver tank 60 are introduced to the portion 32 of the suction passage 30 on the secondary side of the compressor main body 40 and the capacity control valve 10, thereby compressing. When the machine main body 40 is rotating, the pressure on the secondary side of the capacity control valve 10 that has been in a negative pressure state rapidly increases.

  As a result, the auto relief valve 80 that uses the increase in the secondary side pressure of the capacity control valve 10 as a pilot pressure opens the air release circuit 66, and the operation of the auto relief valve 80 causes the compressed gas in the receiver tank 60 to flow into the air filter 70. The air is discharged in the soundproof box of the compressor 1 through

  The compressed gas in the receiver tank 60 released through the air filter 70 is removed by the separator 61 provided in the receiver tank 60, so that the compressed gas is accommodated in the air filter 70 and the soundproof box by this release. Compressed compressor components are not contaminated by lubricating oil.

  In this way, the pressure in the receiver tank 60 is reduced by releasing the compressed gas in the receiver tank 60, and the pressure of the lubricating oil supplied to the regulator 22 by the pressure in the receiver tank 60 is reduced. When the pressure drops below the operation start pressure of 22, the butterfly valve 21 of the auxiliary on-off valve 20 closes the suction passage 30.

  The auxiliary on-off valve 20 formed normally closed by the urging force of the return spring 24 provided in the regulator 22 is not supplied with electric power or the like and thereafter maintains the suction passage 30 in a closed state and compresses it. The inflow of gas or lubricating oil to the air filter 70 side is double blocked by the auxiliary opening / closing valve 20 and the capacity control valve 10.

DESCRIPTION OF SYMBOLS 1 Compressor 3 Body 10 Capacity control valve 12 Valve body 12a Valve shaft 12b Flange 12c Escape passage 13 Valve seat 14 Piston 14a Piston shaft 14b Flange 15 Piston spring 16 Valve body urging spring 20 Auxiliary on-off valve 21 Butterfly valve 22 Regulator 23 Closed Valve pressure chamber 24 Return spring 25 Support shaft 26 Lever 27 Rod 28 Piston 30 Suction passages 31 to 33 (in the suction passage)
34 Sleeve 35 Cylinder 36 Cover 36a Inlet 36b Outlet 37 Pressure receiving chamber 38 Bracket 39 Micro communication path 40 Compressor body 41 Discharge circuit 42 Oil supply circuit 43 Inlet 50 Motor prime mover 60 Receiver tank 61 Separator 62 Supply circuit 63 Capacity control introduction circuit 64 Pressure Regulator 65 Auxiliary oil supply circuit 66 Air release circuit 70 Air filter 71 Relief circuit 72 Restriction 80 Auto relief valve 100 Compressor 110 Capacity control valve 112 Valve body (butterfly valve)
114 regulator 120 start load reducing device 121 start valve 122 bypass circuit 140 compressor main body 141 discharge circuit 142 oil supply circuit 143 intake port 144 check valve 145 oil check valve 150 prime mover 160 receiver tank 161 separator 162 supply circuit 163 introduction circuit 164 pressure regulator 166 Air release circuit 170 Air filter 180 Auto relief valve

Claims (4)

An oil-cooled compressor body driven by a prime mover, a receiver tank that stores compressed gas discharged together with lubricating oil by the compressor body, and the pressure in the receiver tank is equal to or higher than a predetermined capacity control start pressure In a compressor equipped with a normally open type capacity control valve that performs capacity control to sometimes throttle or close the intake port of the compressor body,
An intake passage that communicates with the intake port of the compressor body is provided, and the capacity control valve is disposed in the intake passage, and only gas passes from the primary side to the secondary side when the valve is opened. Provide a valve body with an acceptable check function,
An auxiliary oil supply circuit for discharging the lubricating oil in the receiver tank by internal pressure is communicated with the receiver tank,
An auxiliary on-off valve that is normally closed is provided in the primary or secondary suction passage of the capacity control valve, and a closed pressure receiving chamber of the auxiliary on-off valve communicates with the auxiliary oil supply circuit, and the auxiliary on-off valve An intake portion structure for a compressor, wherein the valve opening start pressure is set to a predetermined normal operation start pressure lower than the capacity control start pressure.   The intake section of a compressor according to claim 1, wherein an oil supply circuit for supplying lubricating oil in the receiver tank to the compressor body is branched, and a circuit obtained by the branch is used as the auxiliary oil supply circuit. Construction.   The receiver tank is opened after a minute communication path that connects the primary side and the secondary side of the auxiliary on-off valve when the auxiliary on-off valve is closed by the auxiliary on-off valve rises to a predetermined rotational speed or higher after starting the compressor. The compressor intake portion structure according to claim 1 or 2, wherein the intake portion structure is formed in a flow passage area that generates an intake amount of the compressor body in which an internal pressure rises above the normal operation start pressure.   4. The compression according to claim 1, further comprising an on-off valve such as an electromagnetic valve that opens the auxiliary oil supply circuit when an operating state of the prime mover becomes equal to or higher than a predetermined rotational speed. Air intake part structure of the machine.

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