Method for controlling operation of engine-driven compressor and engine-driven compressor

Abstract

To prevent shortage in fuel supply to a compressor body immediately after being shifted from a warm-up operation state with start-up load reduced to a normal operation state.SOLUTION: An engine driven compressor 1 has a pressure control valve 13 which opens and closes a control flow passage 12 communicating a valve closing pressure receiving chamber of an intake control valve 11 controlling intake air of a compressor body 40 with a receiver tank 60. The pressure control valve 13 performs opening and closing control of the intake control valve 11 so as to make pressure inside the receiver tank 60 close to predetermined rated pressure. When warm-up operation is started, control over the intake control valve 11 with the pressure control valve 13 is deactivated and the intake control valve 11 is closed along with a start-up of an engine. Before a warm-up operation stopping condition is met after the start-up, pressure inside the receiver tank 60 is increased to fuel supply start pressure which is less than the rated pressure with the intake control valve 11 opened to a predetermined opening less than a full opening. Then, the warm-up operation is completed and shifted to normal operation in which the intake control valve 11 is controlled with the pressure control valve 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an operation control method for an engine-driven compressor and an engine-driven compressor that executes the operation control method, and more specifically, to an operation control method for an engine-driven compressor that enables warm-up operation with a reduced starting load, and an engine-driven compressor that executes the operation control method. [Background technology]

[0002] Engine-driven compressors, which have an engine such as a diesel engine as the driving source for driving the compressor body, are widely used for outdoor work such as civil engineering and construction sites where it is difficult to secure a power source.

[0003] FIG. 9 shows an example of the configuration of an engine-driven compressor 300 having an oil-cooled compressor body 340 that compresses the gas to be compressed together with lubricating oil and discharges the compressed gas as a gas-liquid mixed fluid.

[0004] In addition to the compressor main body 340 and engine 350 described above, this engine-driven compressor 300 is provided with a receiver tank 360 for separating the lubricating oil discharged from the compressor main body 340 together with the compressed gas. The compressed gas from which the lubricating oil has been separated in this receiver tank 360 is passed through an oil separator 366 to further remove oil, and is then configured so that it can be supplied to the consumer side to which an air work machine or the like (not shown) is connected.

[0005] The lubricating oil recovered in the receiver tank 360 is configured to be supplied to the compressor body 340 via an oil supply passage 364 equipped with an oil cooler 363 and an oil filter 367, by utilizing the pressure within the receiver tank 360.

[0006] Such an engine-driven compressor 300 is provided with an intake adjustment device 310 that adjusts the intake volume of the compressor main body 340 according to the pressure in the receiver tank 360 so as to supply compressed gas at a stable pressure to the consumption side.

[0007] As this intake adjustment device 310, the engine-driven compressor 300 shown in Figure 9 is provided with an intake adjustment valve 311 that opens and closes the intake port 341 of the compressor main body 340, and an unloader regulator 316 that controls the opening and closing of this intake adjustment valve 311.

[0008] This unloader regulator 316 is connected to the receiver tank 360 via a control passage 312, and the control passage 312 is provided with a pressure regulating valve 313 that opens the control passage 312 when the pressure in the receiver tank 360 is equal to or higher than a predetermined rated pressure.

[0009] In addition, the symbol 314 in Figure 9 is a relief flow path, and when the pressure regulating valve 313 closes the control flow path 312 and the introduction of compressed gas to the unloader regulator 316 stops, the compressed gas in the pressure-receiving chamber of the unloader regulator 316 is released through the throttle 315, and the unloader regulator 316 can be returned to the fully open position by the force of a return spring (not shown).

[0010] By providing the intake adjustment device 310 configured in this manner, when the pressure in the receiver tank 360 reaches or exceeds the rated pressure, the pressure adjustment valve 313 begins to open, and the introduction of compressed gas in the receiver tank 360 to the unloader regulator 316 begins, and the intake adjustment valve 311 throttles or closes the intake port 341 of the compressor main body 340. When the pressure in the receiver tank 360 falls below the rated pressure, the pressure adjustment valve 313 closes and the intake adjustment valve 311 opens the intake port 341 of the compressor main body 340, thereby adjusting the intake of the compressor main body 340 so that the pressure in the receiver tank 360 approaches the aforementioned rated pressure.

[0011] In the engine-driven compressor 300 configured as above, the engine 350 which is the drive source of the compressor main body 340 has a small torque in the low rotation range and is prone to stalling when a load is applied at start-up.

[0012] In particular, in engine-driven compressors equipped with small engines that have had their maximum output increased by adopting a common rail system or adding a turbocharger due to the demand for downsizing engines to comply with exhaust gas regulations, the engine starting torque is smaller than that of conventional engines that generate the same maximum output, making them more susceptible to stalling during startup.

[0013] On the other hand, in the engine-driven compressor 300, the compressor body 340, which is the load on the engine 350, is directly connected to the engine 350, and the engine 350 is subjected to a load associated with the rotation of the compressor body 340 from the time of starting. Therefore, if the load received from the compressor body 340 can be reduced as much as possible when the engine 350 is started, the engine 350 can be started smoothly.

[0014] Focusing on the configuration of such an engine-driven compressor 300, in order to reduce the load on the engine 350 at startup, Patent Document 1 listed below discloses a configuration provided with a startup load reduction device shown by reference symbol 320 in FIG. 9.

[0015] This startup load reduction device 320 is composed of a bypass flow path 321 that bypasses the pressure regulating valve 313 and connects the unloader regulator 316 to the receiver tank 360, and a bypass valve 325 that opens and closes this bypass flow path 321.At startup, by operating the bypass valve 325 to open the bypass flow path 321, the unloader regulator 316 can be connected directly to the receiver tank 360 without going through the pressure regulating valve 313.

[0016] As a result, when the engine 350 is started with the bypass flow path 321 open in this manner, the compressor main body 340 begins to rotate and the pressure in the receiver tank 360 rises, the unloader regulator 316 operates to close the intake control valve 311 and operate the compressor main body 340 without load, thereby reducing the load on the engine 350 at the beginning of startup.

[0017] After the operating condition of the engine 350 has stabilized, the bypass valve 325 provided in the starting load reduction device 320 is operated to close the bypass passage 321, and the pressure control valve 313 transitions to normal operation by opening and closing the control passage 312 depending on the pressure in the receiver tank 360, thereby enabling known intake adjustment to be performed.

[0018] In addition, the above-mentioned Patent Document 1 discloses a configuration in which a manual opening and closing valve is provided as the aforementioned bypass valve 325, but by changing this to an electromagnetic valve, an engine-driven compressor has also been proposed in which the opening and closing operation of the bypass valve 325 can be electrically controlled based on the detected operating state of the engine (see Patent Document 2). [Prior art documents] [Patent documents]

[0019] [Patent Document 1] JP 2002-168177 A [Patent Document 2] JP 2017-115598 A Summary of the Invention [Problem to be solved by the invention]

[0020] As described above, in a configuration in which the bypass valve 325 is constructed using an electromagnetic valve and its opening and closing can be electrically controlled, as shown in Figure 10(A), by starting the engine with the bypass valve 325 open, as soon as the compressor body starts to rotate together with the engine, the intake control valve 311 is closed immediately, and warm-up operation is performed with reduced starting load, and once the warm-up is completed and the engine is operating stably, the bypass valve 325 is closed and the pressure control valve 313 can transition to normal operation by opening and closing the control flow path 312 according to the pressure in the receiver tank 360, as shown in Figure 10(B).

[0021] In this way, by starting and warming up the engine under conditions where the load is reduced as much as possible, the engine can be started under conditions where it is less likely to stop (stall).

[0022] However, in an engine-driven compressor configured in this manner, as shown in Figure 10(A), during warm-up operation, the intake port 341 of the compressor body 340 is closed, and the pressure inside the receiver tank 360 is at a low pressure, for example, a gauge pressure of 0.1 MPa (see Figure 11(B)).

[0023] Therefore, since the pressure regulating valve 313 is in a closed state, when the bypass valve 325 is closed to end the warm-up operation and transition to normal operation is made, the introduction of compressed gas to the intake regulating valve 311 is stopped and the intake regulating valve 311 opens (Figure 10(B)), the compressor main body 340 starts compression, and the pressure in the receiver tank 360 rises to a pressure above the rated pressure (see Figure 11(B)).

[0024] This increase in pressure in the receiver tank 360 will result in an increase in the amount of oil supplied to the compressor main body 340. However, since this increase in the amount of oil supplied to the compressor main body 340 occurs after the pressure in the receiver tank 360 has increased, the compressed gas will be compressed without sufficient lubricating oil being supplied during the period from when normal operation is switched over to until the pressure in the receiver tank 360 has increased to a certain extent.

[0025] When such a shortage of oil occurs, the heat of compression generated in the compressor body 340 is not sufficiently cooled, causing the discharge temperature of the compressor body 340 to rise excessively.In particular, in the compressor body 340 which generates high-pressure compressed gas, the abnormal rise in discharge temperature causes malfunctions such as emergency stops of the engine-driven compressor.

[0026] Therefore, the present invention has been made to eliminate the drawbacks of the above-mentioned conventional technology, and aims to provide an operation control method for an engine-driven compressor that can eliminate the lack of oil supply to the compressor body immediately after the warm-up operation, which reduces the starting load, is completed and the compressor transitions to normal operation, thereby preventing the occurrence of abnormal increases in discharge temperature due to insufficient oil supply, and an engine-driven compressor that executes the operation control method. [Means for solving the problem]

[0027] The means for solving the problems are described below together with the reference numerals used in the description of the embodiment of the invention. The reference numerals are used to clarify the correspondence between the description of the claims and the description of the embodiment of the invention, and needless to say, are not used to restrict the interpretation of the technical scope of the present invention.

[0028] In order to achieve the above object, the operation control method of the engine-driven compressor of the present invention comprises the steps of: An operation control method for an engine-driven compressor 1 including an engine (not shown), an oil-cooled compressor body 40 driven by the engine, a receiver tank 60 which introduces a gas-liquid mixture of compressed gas and lubricating oil discharged from the compressor body 40 and separates the gas and lubricating oil, and supplies the separated lubricating oil to the compressor body 40 using internal pressure, an intake regulating valve 11 which controls intake to the compressor body 40, a control flow path 12 which communicates between a closed valve pressure receiving chamber 113 of the intake regulating valve 11 and the receiver tank 60, and a pressure regulating valve 13 which controls the opening and closing operation of the intake regulating valve 11 by opening the control flow path 12 when the pressure in the receiver tank 60 is equal to or higher than a predetermined rated pressure, and closing the control flow path 12 when the pressure in the receiver tank 60 is lower than the rated pressure, The control of the intake control valve 11 by the pressure control valve 13 is disabled, and the intake control valve 11 is closed when the engine is started to start a warm-up operation, and After the engine is started, before a predetermined warm-up end condition is satisfied, the intake control valve 11 is opened to a predetermined opening degree less than full opening, thereby performing a discharge pressure increase process to increase the pressure in the receiver tank 60 to a fuel supply start pressure, which is a predetermined lower pressure than the rated pressure, When the warm-up operation end condition is satisfied, the warm-up operation is ended and a transition is made to normal operation in which the intake control valve 11 is controlled by the pressure control valve 13 (claim 1).

[0029] A bypass flow passage 20 (21, 22) is provided which bypasses the pressure regulating valve 13 and communicates between the receiver tank 60 and the closed valve pressure receiving chamber 113 of the intake regulating valve 11, and the engine is started in a state in which the receiver tank 60 and the closed valve pressure receiving chamber 113 of the intake regulating valve 11 are communicated through the bypass flow passage 20 (21, 22), thereby disabling the control of the intake regulating valve 11 by the pressure regulating valve 13 and closing the intake regulating valve 11 as the engine starts, The discharge pressure increasing process is performed by throttling the flow rate of the compressed gas introduced into the closed valve pressure receiving chamber 113 of the intake control valve 11 through the bypass flow path 20 (21, 22), The warm-up operation can be terminated by closing the bypass passage 20 (21, 22), and the engine can be configured to transition to normal operation in which the intake regulating valve 11 is controlled by the pressure regulating valve 13 (claim 2).

[0030] Or, a starting control flow passage 51 that bypasses the pressure regulating valve 13 and communicates between the closing valve pressure receiving chamber 113 of the intake regulating valve 11 and the receiver tank 60; a start pressure regulating valve (52) for controlling the opening and closing of the intake regulating valve (11) by opening the start control passage (51) when the pressure in the receiver tank (60) is equal to or higher than a start unload pressure, which is a predetermined higher pressure than the fuel supply start pressure and a predetermined lower pressure than the rated pressure, and closing the start control passage (51) when the pressure in the receiver tank (60) is lower than the start unload pressure, After the discharge pressure increase process, before the warm-up operation end condition is satisfied, the intake control valve 11 is controlled by the starting pressure control valve 52, When the warm-up operation termination condition is satisfied, the control of the intake control valve 11 by the starting pressure control valve 52 is terminated and the warm-up operation is terminated, and the engine is transitioned to the normal operation in which the intake control valve 11 is controlled by the pressure control valve 13 (Claim 3).

[0031] Even in the configuration in which the above-mentioned starting control flow path 51 and starting pressure regulating valve 52 are provided, a bypass flow path 20 (21, 22) is provided which bypasses the pressure regulating valve 13 and communicates between the receiver tank 60 and the closed valve pressure receiving chamber 113 of the intake regulating valve 11, and the engine is started in a state in which the receiver tank 60 and the closed valve pressure receiving chamber 113 of the intake regulating valve 11 are communicated through the bypass flow path 20 (21, 22). This disables the control of the intake regulating valve 11 by the pressure regulating valve 13 and the starting pressure regulating valve 52, and closes the intake regulating valve 11 as the engine starts. The discharge pressure increasing process is performed by throttling the flow rate of the compressed gas introduced into the closed valve pressure receiving chamber 113 of the intake control valve 11 through the bypass flow path 20 (21, 22), It may be configured such that, after a predetermined time has elapsed since the discharge pressure increasing process, the bypass flow path 20 (21, 22) is closed and control of the intake regulating valve 11 by the starting pressure regulating valve 52 is started (claim 4).

[0032] In any of the above configurations, the discharge pressure increasing process may be performed while increasing the opening degree of the intake regulating valve 11 in a stepwise manner (claim 5).

[0033] In addition, in a configuration in which a start-up control flow passage 51 and a start-up pressure regulating valve 52 are provided, a plurality of start-up control flow passages 51 (51a, 51b...51z) are provided, the start-up pressure regulating valve 52 (52a, 52b...52z) is provided in each of the start-up control flow passages 51 (51a, 51b...51z), and the operating pressure of each start-up pressure regulating valve 52 (52a, 52b...52z) is set to a different pressure, After the discharge pressure increase process, the control of the intake control valve 11 by the starting pressure control valve 52 (52a, 52b,...52z) until the warm-up operation end condition is satisfied may be performed by switching sequentially from the starting pressure control valve 52 (52a, 52b,...52z) with the lowest operating pressure to the starting pressure control valve 52 (52a, 52b,...52z) with the highest operating pressure at predetermined time intervals (Claim 6).

[0034] In addition, the engine-driven compressor 1 of the present invention is An engine-driven compressor 1 includes an engine (not shown), an oil-cooled compressor body 40 driven by the engine, a receiver tank 60 that introduces a gas-liquid mixture of compressed gas and lubricating oil discharged from the compressor body 40 and separates the gas and lubricating oil, and supplies the separated lubricating oil to the compressor body 40 using internal pressure, an intake regulating valve 11 that controls intake to the compressor body 40, a control flow path 12 that communicates between a closed valve pressure receiving chamber 113 of the intake regulating valve 11 and the receiver tank 60, and a pressure regulating valve 13 that controls the opening and closing operation of the intake regulating valve 11 by opening the control flow path 12 when the pressure in the receiver tank 60 is equal to or higher than a predetermined rated pressure and closing the control flow path 12 when the pressure in the receiver tank 60 is lower than the rated pressure, a bypass flow passage 20 that bypasses the pressure regulating valve 13 and communicates between the receiver tank 60 and the closed valve pressure receiving chamber 113 of the intake regulating valve 11; A flow area change device (23, 24) that changes the flow area of ​​the bypass flow path (20); A control device (controller) 30 for controlling the flow path area change device (23, 24) is provided, The control device (controller) 30 controls the flow path area change device (23, 24), When the engine is started, the flow passage area of ​​the bypass flow passage 20 is maximized, and the intake control valve 11 is closed at the same time as the engine is started to start warming up, After the engine is started, before a predetermined warm-up operation completion condition is satisfied, a discharge pressure increase process is performed to increase the pressure in the receiver tank 60 to a fuel supply start pressure, which is a predetermined lower pressure than the rated pressure, by reducing the flow passage area of ​​the bypass flow passage 20 and opening the intake control valve 11 to a predetermined opening degree less than full opening, and When the warm-up operation termination condition is satisfied, the bypass passage 20 is blocked to terminate the warm-up operation, and the engine transitions to normal operation in which the intake control valve 11 is controlled by the pressure control valve 13 (Claim 7).

[0035] Another engine-driven compressor 1 of the present invention is as follows: An engine-driven compressor 1 includes an engine (not shown), an oil-cooled compressor body 40 driven by the engine, a receiver tank 60 that introduces a gas-liquid mixture of compressed gas and lubricating oil discharged from the compressor body 40 and separates the gas and lubricating oil, and supplies the separated lubricating oil to the compressor body 40 using internal pressure, an intake regulating valve 11 that controls intake to the compressor body 40, a control flow path 12 that communicates between a closed valve pressure receiving chamber 113 of the intake regulating valve 11 and the receiver tank 60, and a pressure regulating valve 13 that controls the opening and closing operation of the intake regulating valve 11 by opening the control flow path 12 when the pressure in the receiver tank 60 is equal to or higher than a predetermined rated pressure and closing the control flow path 12 when the pressure in the receiver tank 60 is lower than the rated pressure, a bypass flow passage 20 and a starting control flow passage 51 which bypass the pressure regulating valve 13 and communicate between the receiver tank 60 and the closed valve pressure receiving chamber 113 of the intake regulating valve 11; A flow area change device (23, 24) that changes the flow area of ​​the bypass flow path (20); A start-up pressure regulating valve 52 provided in the start-up control flow passage 51, which opens when the discharge side pressure of the compressor body 40 is equal to or higher than a start-up unloading pressure, which is a predetermined pressure lower than the rated pressure, and closes when the discharge side pressure is lower than the start-up unloading pressure; A start-up control flow passage solenoid valve 53 is provided in the start-up control flow passage 51 and is connected in series with the start-up pressure regulating valve 52; A control device (controller) 30 is provided to control the flow path area change device (23, 24) and the start control flow path solenoid valve 53, The control device (controller) 30 includes: When the engine is started, the starting control flow passage solenoid valve 53 is opened, and the flow passage area change device (23, 24) is operated to maximize the flow passage area of ​​the bypass flow passage 20, thereby starting the engine and closing the intake control valve 11 to start a warm-up operation. After the engine is started, before a predetermined warm-up operation completion condition is satisfied, the flow area change device (23, 24) is controlled to reduce the flow area of ​​the bypass flow path 20 and the intake control valve 11 is opened to a predetermined opening degree less than full opening, thereby performing a discharge pressure increase process to increase the pressure in the receiver tank 60 to a fuel supply start pressure, which is a predetermined lower pressure than the starting unload pressure, After the discharge pressure increase process, before the warm-up operation end condition is satisfied, the bypass flow path 20 is closed, and control of the intake control valve 11 is shifted to the start pressure control valve 52, When the warm-up operation termination condition is satisfied, the solenoid valve 53 for the starting control flow path is closed to terminate the control of the intake control valve 11 by the starting pressure control valve 52, and the warm-up operation is terminated, and a transition is made to normal operation in which the intake control valve 11 is controlled by the pressure control valve 13 (Claim 8).

[0036] In both of the engine-driven compressors 1, the bypass flow passage 20 is formed as an assembly of a plurality of parallel flow passages (first and second bypass flow passages 21, 22) arranged in parallel, and a parallel flow passage solenoid valve (first and second solenoid valves 23, 24) is provided in each of the parallel flow passages (first and second bypass flow passages 21, 22), so that the parallel flow passage solenoid valves (first and second solenoid valves 23, 24) function as the flow passage area change device, The control device (controller) 30, When the engine is started, all of the parallel flow path solenoid valves (first and second solenoid valves 23, 24) are opened, The discharge pressure increasing process may be configured to be performed by leaving at least one of the parallel flow path solenoid valves (first and second solenoid valves 23, 24) and closing them sequentially at predetermined time intervals (claim 9).

[0037] Furthermore, in a configuration in which a start-up control flow passage 51 and a start-up pressure adjustment valve 52 are provided, a plurality of start-up control flow passages 51 (51a, 51b...51z) are provided, and each of the start-up control flow passages 51 (51a, 51b...51z) is provided with a start-up control flow passage solenoid valve 53 (53a, 53b...53z) that opens and closes the start-up control flow passage 51 (51a, 51b...51z), and a start-up pressure adjustment valve 52 (52a, 52b...52z) having different operating pressures, The control device (controller) 30, When the engine is started, all of the starting control flow path solenoid valves 53 (53a, 53b, . . . 53z) are opened, After the bypass flow path 20 is blocked, the solenoid valves 53a for the starting control flow path provided in the starting control flow path 51a in which the starting pressure regulating valve 52a having the lowest operating pressure are provided are successively closed at predetermined time intervals, and when the warm-up operation end condition is satisfied, the solenoid valve 53z for the starting control flow path provided in the starting control flow path 51z in which the starting pressure regulating valve 52z having the highest operating pressure is provided is closed (Claim 10). Effect of the Invention

[0038] With the configuration of the present invention described above, the engine-driven compressor 1 implementing the operation control method of the present invention can provide the following remarkable effects.

[0039] By performing a discharge pressure increase process in which the intake control valve 11 is opened less than fully open before the warm-up operation is completed, and the pressure in the receiver tank 60 is increased to the oil supply start pressure, the supply of lubricating oil necessary for lubricating and cooling the compressor main body 40 is secured. Even if the warm-up operation release condition is subsequently met and control of the intake control valve 11 is transferred to the pressure control valve 13, it is possible to effectively prevent the occurrence of abnormal increases in discharge temperature due to insufficient lubricating oil supply, and it is possible to prevent emergency stop of the engine-driven compressor due to abnormal increases in discharge temperature.

[0040] This discharge pressure increase process increases the pressure in the receiver tank 60 by opening the intake control valve 11 less than fully open, and therefore within a predetermined low pressure range relative to the rated pressure. Therefore, the load on the engine is smaller than when the pressure in the receiver tank 60 is increased to the rated pressure, and the engine can be effectively prevented from stopping (stalling) even if the discharge pressure increase process is performed during warm-up operation.

[0041] In addition to the control flow path 12 and the pressure regulating valve 13, a start-up control flow path 51 and a start-up pressure regulating valve 52 that opens at a pressure lower than that of the pressure regulating valve 13 are provided, and in this configuration, after the discharge pressure increase process, the intake regulating valve 11 is controlled by the start-up pressure regulating valve 52 until the warm-up operation end condition is met.In this configuration, before transitioning to normal operation in which the intake regulating valve is controlled by the pressure regulating valve 13, the pressure in the receiver tank 60 can be increased from the above-mentioned oil supply start pressure to a predetermined start unload pressure that is higher than the oil supply start pressure but lower than the rated pressure.By increasing the amount of oil supplied to the compressor main body 40 during warm-up operation, it is possible to more reliably prevent the occurrence of an abnormal rise in discharge temperature when transitioning to normal operation thereafter.

[0042] In a configuration in which the discharge pressure increase process is performed in stages, and in which multiple starting pressure regulating valves 52 with different operating pressures are applied in sequence starting with the lowest operating pressure, the pressure in the receiver tank 60, and therefore the back pressure of the compressor main body 40, is increased as the engine warms up, gradually increasing the load on the engine. This configuration makes it possible to increase the amount of oil supplied to the compressor main body 40 before switching to normal operation to an amount close to the amount of oil supplied during normal operation, while still effectively preventing the engine from stopping (stalling) during warm-up operation. [Brief description of the drawings]

[0043] [Figure 1] 1 is an explanatory diagram of an overall configuration of an engine-driven compressor according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of the configuration of an intake regulating valve. [Diagram 3] FIG. 4 is a cross-sectional view showing a modified example of the intake regulating valve. [Figure 4] FIG. 2 is a functional block diagram of the engine-driven compressor of the present invention. [Diagram 5] 1A is an explanatory diagram of the operation of the engine-driven compressor of the present invention (under normal conditions), (A) is an explanatory diagram of the operation at startup, (B) is an explanatory diagram of the operation at the time of increasing the discharge pressure, and (C) is an explanatory diagram of the operation at normal operation. [Figure 6] 6A is a time chart showing the operation of each part of the engine-driven compressor during operation in FIG. 5, and FIG. 6B is a graph showing the change in pressure in the receiver tank. [Figure 7] 1A is an explanatory diagram of the operation of the engine-driven compressor of the present invention (in extreme cold), (A) is an explanatory diagram of the operation at startup, (B) is an explanatory diagram of the operation at the time of increasing the discharge pressure, (C) is an explanatory diagram of the operation at the time of control by the startup pressure control valve, and (D) is an explanatory diagram of the operation at the time of normal operation. [Figure 8] 8A is a time chart showing the operation of each part of the engine-driven compressor during operation in FIG. 7, and FIG. 8B is a graph showing the change in pressure in the receiver tank. [Figure 9] FIG. 1 is an explanatory diagram of a conventional engine-driven compressor equipped with a startup load reduction device (corresponding to FIG. 1 of Patent Document 1). [Figure 10]FIG. 1 is an explanatory diagram of an engine-driven compressor equipped with a startup load reduction device, where (A) shows the operation of each part at startup, and (B) shows the operation of each part during normal operation. [Figure 11] 11A is a time chart showing the operation of each part of the engine-driven compressor during operation in FIG. 10, and FIG. 11B is a graph showing the change in pressure in the receiver tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] The configuration of the present invention will be described below with reference to the accompanying drawings.

[0045] [Overall configuration of engine-driven compressor] Reference numeral 1 in Figure 1 denotes the engine-driven compressor of the present invention. This engine-driven compressor 1 comprises a compressor main body 40, an engine (not shown) that drives the compressor main body 40, and a receiver tank 60 that stores the compressed gas discharged from the compressor main body 40. The compressed gas discharged from the compressor main body 40 is stored in the receiver tank 60, and is configured so that it can be supplied to an air work machine (not shown) connected to a service valve 66 via a pressure regulating valve 61.

[0046] The aforementioned compressor main body 40 is an oil-cooled screw compressor that compresses the gas to be compressed together with lubricating oil for lubrication, cooling and sealing, and the compressed gas discharged as a gas-liquid mixed fluid with the lubricating oil is introduced into the receiver tank 60 via a discharge passage 62, and the receiver tank 60 is configured to be able to separate the lubricating oil and the compressed gas, and is also equipped with an oil supply passage 64 that supplies the lubricating oil recovered in the receiver tank 60 again to the compressor main body 40 via an oil cooler 63.

[0047] [Intake adjustment device] The engine-driven compressor 1 configured as described above is similar to the configuration of the conventional engine-driven compressor described with reference to Figures 9 and 10 in that it is equipped with an intake adjustment device 10 that performs intake adjustment by throttling or closing the intake port 41 of the compressor main body 40 when the pressure in the receiver tank 60 reaches or exceeds a predetermined rated pressure, and fully opening it when the pressure falls below the rated pressure, so that the pressure in the receiver tank 60 approaches the predetermined rated pressure.

[0048] 9 and 10 in that it is composed of an intake regulating valve 11 which controls the opening and closing of the intake port 41 of the compressor main body 40, a control passage 12 which connects the closed-valve pressure chamber 113 of the intake regulating valve 11 with the receiver tank 60, and a pressure regulating valve 13 which opens the control passage 12 when the pressure in the receiver tank 60 is equal to or higher than a predetermined rated pressure, and closes the control passage 12 when the pressure in the receiver tank 60 is below the rated pressure, depending on the pressure in the receiver tank 60, and also in that it is provided with a relief passage 14 which releases the compressed gas in the closed-valve pressure chamber 113 through a throttle 15.

[0049] [Intake adjustment valve] The aforementioned intake adjustment valve 11 that constitutes the intake adjustment device 10 opens and closes the intake port 41 of the compressor main body 40 as described above, and in this embodiment, the intake adjustment valve 11 shown in Figure 2 is used as an example.

[0050] The intake control valve 11 shown in Figure 2 has an intake passage 115 through which the compressed gas passes, defined by a space formed within a body (valve box) 111, and is configured so that the intake passage 115 can be blocked by seating a valve body 116 on a valve seat 115a provided within this intake passage 115.

[0051] This valve body 116 is a so-called "umbrella valve" in which a valve shaft 116a is attached to a disk-shaped valve body 116, and is configured so that by inserting the valve shaft 116a into a cylindrical sleeve 117 formed within the body 111 and moving the valve body 116 back and forth in the axial direction of the sleeve 117, it can move between a closed position in which the valve body 116 is seated on the valve seat 115a, and an open position in which the valve body 116 is separated from the valve seat 115a.

[0052] In order to enable such movement of the valve body 116, a cylinder 112 that communicates with the intake passage 115 via the aforementioned sleeve 117 is formed coaxially with the sleeve 117 in the valve box 111 of the intake control valve 11.

[0053] This cylinder 112 forms an airtight chamber with the valve shaft 116a inserted into the sleeve 117 and the end opposite the formation side of the sleeve 117 blocked by an end plate 118. The inside of this airtight chamber (cylinder) 112 is divided into two chambers via a pressure receiving body 119 connected to the other end of the valve shaft 116a, which in this embodiment is a piston, so that a closed valve pressure receiving chamber 113 of the intake control valve 11 is formed on the end plate 118 side, and an auxiliary pressure receiving chamber 114 is formed on the opposite side to the closed valve pressure receiving chamber 113 via the piston 119.

[0054] In the illustrated configuration, in order to make the intake control valve 11 a normally open (NO) type, a spring 114a that presses the piston 119 toward the closed valve pressure chamber 113 is accommodated in the auxiliary pressure chamber 114 described above, giving the auxiliary pressure chamber 114 the function of a spring chamber; however, if the intake control valve 11 can be made a normally open type, the spring 114a does not necessarily have to be provided in the auxiliary pressure chamber 114.

[0055] Incidentally, as the intake regulating valve 11, instead of the one having the configuration shown in FIG. 2, an intake regulating valve 11 having a structure with a backflow prevention function as shown in FIG. 3 may be adopted.

[0056] In this configuration, the valve shaft is divided into a valve shaft 116a' provided on the valve body 116 side and a valve shaft 119a provided on the pressure-receiving body (piston) 119 side, and a spring 116b is provided between the valve shaft 116a' on the valve body 116 side and the valve shaft 119a on the pressure-receiving body (piston) 119 side to urge the valve body 116 toward the valve seat 115a.

[0057] The valve element 116 is configured to come into contact with the valve seat 115a due to the biasing force of this spring 116b even when the pressure receiving body (piston) 119 is in the valve open position on the left side of the drawing.

[0058] The biasing force of this spring 116b is weak, and when the pressure receiving body (piston) 119 is in the open position on the left side of the paper, if the pressure in the intake passage 115 on the secondary side of the valve seat 115a becomes negative, the valve body 116 moves away from the valve seat 115a, and the compressor body 40 is configured to be able to suck in the compressed gas.

[0059] On the other hand, even when the pressure receiving body (piston) 119 is in the open position on the left side of the paper, if the pressure in the secondary intake passage 115 rises relative to the valve seat 115a, the valve body 116 is pressed against the valve seat 115a, thereby preventing backflow.

[0060] In this way, when the engine-driven compressor 1 of the present invention employs an intake regulating valve 11 with a backflow prevention function, even if the valve body 116 is in contact with the valve seat 115a, when the pressure in the intake passage on the secondary side of the valve seat 115a becomes lower than the pressure in the intake passage on the primary side of the valve seat 115a, the valve body 116 moves away from the valve seat 115a and the compressor main body 40 can take in air, this is included in the "open" or "valve open" state of the intake regulating valve 11.

[0061] In addition, in the configuration of the intake regulating valve 11 described with reference to Figures 2 and 3, not only the valve body 116 and valve seat 115a but also the cylinder 112 and piston 119 for moving the valve body 116 back and forth are all provided within a common body (valve box) 111. However, as in the conventional engine-driven compressor described with reference to Figure 9, a configuration in which the intake regulating valve main body without a valve body drive mechanism and a drive mechanism such as an unloader regulator that drives the valve body of this intake regulating valve main body are each separate may be adopted, and in this case the aforementioned closed valve pressure chamber 113, auxiliary pressure chamber 114 and pressure body 119 are formed within the unloader regulator.

[0062] Furthermore, in the intake control valve 11 described with reference to Figures 2 and 3, a configuration is adopted in which the inside of the cylinder 112, which is an airtight chamber as the driving mechanism for the valve body 116, is partitioned by providing a piston 119 as a pressure receiving body that moves under the pressure of the compressed gas introduced into the closed-valve pressure receiving chamber 113. However, the pressure receiving body 119 is not limited to the above-mentioned piston, and the pressure receiving body 119 may be, for example, a diaphragm or the like, as long as it is capable of controlling the operation of the valve body 116 by the compressed gas introduced into the closed-valve pressure receiving chamber 113.

[0063] [Bypass flow path] In addition to the aforementioned control passage 12, a bypass passage 20 is also connected to the closed valve pressure chamber 113 of the intake regulating valve 11 configured as described above, so that the compressed gas in the receiver tank 60 can be introduced into the closed valve pressure chamber 113 of the intake regulating valve 11 by bypassing the pressure regulating valve 13 provided in the control passage 12.

[0064] This bypass flow passage 20 is provided with a flow passage area changing device that makes the flow passage area of ​​the bypass flow passage 20 variable, and is configured so that the flow passage area of ​​the bypass flow passage 20 can be changed to change the flow rate of compressed gas introduced into the closed valve pressure chamber 113 of the intake control valve 11, thereby changing the opening degree of the intake control valve 11.

[0065] In order to make the flow area of ​​the bypass flow passage 20 variable, in this embodiment, the aforementioned bypass flow passage 20 is configured as an assembly of two parallel flow passages (first bypass flow passage 21 and second bypass flow passage 22), and a solenoid valve (first solenoid valve 23, second solenoid valve 24) is provided in each of the first bypass flow passage 21 and the second bypass flow passage 22. The flow area of ​​the bypass flow passage 20 is maximum when both the first and second solenoid valves 23, 24 are open, and the flow area can be narrowed by closing either one of the first and second solenoid valves 23, 24, and the bypass flow passage 20 can be blocked by closing both the first and second solenoid valves 23, 24.

[0066] Therefore, in the illustrated embodiment, the first and second solenoid valves 23, 24 serve as the above-mentioned flow path area changing device that changes the flow path area of ​​the bypass flow path.

[0067] In the embodiment shown in FIG. 1, one end of the common passage 25, the other end of which is connected to the receiver tank 60, is connected to an aluminum alloy block manifold 26 and branched off, and one end of the control passage 12, the first bypass passage 21, and the second bypass passage 22 are each connected to this block manifold 26, and the other end is each connected to the closed valve pressure chamber 113 of the intake control valve 11. However, one ends of the control passage 12, the first bypass passage 21, and the second bypass passage 22 may also be connected directly to the receiver tank 60 as shown in FIGS. 5 and 7, without going through the block manifold 26 or the common passage 25 described above.

[0068] In this embodiment, the first solenoid valve 23 provided in the first bypass flow path 21 is a normally open (NO) type solenoid valve, and a normally closed (NC) type solenoid valve is used as the second solenoid valve 24 provided in the second bypass flow path 22, but this configuration is not limited to this and various combinations can be adopted.

[0069] In addition, in Figures 1 to 3, symbol 27 is a three-way solenoid valve, and the C port of this three-way solenoid valve 27 is connected to the auxiliary pressure chamber 114 (spring chamber: see Figures 2 and 3) of the intake regulating valve 11 via flow path 28c, the flow path 28a attached to the A port is connected to the suction flow path 115 of the intake regulating valve 11 on the secondary side of the valve seat 115a, and the flow path 28b attached to the B port is connected to the primary side of the intake regulating valve 11.

[0070] This allows the auxiliary pressure chamber 114 of the intake regulating valve 11 to be selectively connected to the intake passage 115 on the secondary side of the valve seat 115a and the primary side of the intake regulating valve 11 by switching the three-way solenoid valve 27.

[0071] [Starting control flow path] The engine-driven compressor 1 of the present invention may further be provided with a starting control passage 51 that bypasses the pressure regulating valve 13 provided in the control passage 12 and connects between the receiver tank 60 and the closed valve pressure chamber 113 of the intake regulating valve 11.

[0072] This startup control flow path 51 is provided with a startup pressure regulating valve 52 which opens when the pressure in the receiver tank 60 reaches a predetermined startup unload pressure or higher and closes when the pressure falls below the startup unload pressure. In addition, a startup control flow path solenoid valve 53, which is an electromagnetic valve (in this embodiment, a normally closed (NC) type solenoid valve), is provided in series with the startup pressure regulating valve 52.

[0073] The above-mentioned starting unload pressure is set to a pressure that is a predetermined higher than the fuel supply start pressure and a predetermined lower than the rated pressure. Therefore, when the bypass passage 20 is closed while the starting control passage 51 is opened by the starting control passage solenoid valve 53, the starting pressure regulating valve 52, whose operating pressure is set lower than that of the pressure regulating valve 13, is configured to begin opening and closing control of the intake regulating valve 11.

[0074] In addition, the start-up control flow passage 51, the start-up pressure regulating valve 52, and the solenoid valve 53 for the start-up control flow passage may not be provided in, for example, a standard specification engine-driven compressor 1, but may be provided only in an engine-driven compressor 1 for cold climates.

[0075] In addition, the aforementioned starting control flow passage 51, starting pressure regulating valve 52, and starting control flow passage solenoid valve 53 may be provided one each, but as shown as a "modified example" in Figure 1, two or more starting control flow passages 51a, 51b...51z may be provided in parallel, and starting pressure regulating valves 52a, 52b...52z and starting control flow passage solenoid valves 53a, 53b...53z may be provided in each of the starting control flow passages 51a, 51b...51z.

[0076] In this case, the operating pressure of each of the startup pressure regulating valves 52a, 52b,...52z can be set to a different value, and the startup control flow path solenoid valves 53a, 53b,...53z can be opened, and then the startup control flow path solenoid valves provided in the startup control flow path in which the startup pressure regulating valve with the lower operating pressure is provided are sequentially closed, thereby allowing the startup unload pressure to increase in stages.

[0077] (Switches, sensors, etc.) The engine-driven compressor 1 of the present invention configured as described above is provided with a controller 30, which is a control device that controls the operation of each part of the engine-driven compressor 1, as well as switches and sensors that output electrical signals to the controller 30 (see Figure 4).

[0078] Of these switches, switches for performing operations such as turning on and off the main power supply of the engine-driven compressor 1, starting and stopping the engine, etc. (to cause a controller 30, described later, to perform these operations) can be provided.

[0079] As an example, in the embodiment shown in FIG. 4, a main switch 70 and a start switch 72 are provided on an operation panel of the engine-driven compressor 1 as such switches.

[0080] Of these, the main switch 70 switches the main power supply of the engine-driven compressor 1 between "ON" and "OFF", and in the illustrated embodiment, a rotary switch that can be switched between two positions, ON and OFF, is used as this main switch 70.

[0081] Of these, "OFF" is a stopped state in which electricity is no longer flowing to each part of the engine-driven compressor 1, and "ON" is the so-called "accessory position," in which electricity is flowing to the engine, electronic control devices such as the controller 30, various sensors, instruments, etc.

[0082] The start switch 72 is a switch for starting the engine, and in this embodiment is configured as a push button switch, and when this switch is pressed for a predetermined period of time (for example, one second) or longer, electricity is applied to the engine's starter motor, causing the engine to start.

[0083] In the configuration of the engine-driven compressor 1 having such a main switch 70 and start switch 72, the engine-driven compressor 1 can be started and continued to operate by rotating the main switch 70 from the "OFF" position to the "ON" position, and then pressing and holding the start switch 72 to start the engine, and the engine-driven compressor 1 can be stopped by rotating the main switch 70 from the "ON" position to the "OFF" position.

[0084] As mentioned above, the switch for starting and stopping the engine-driven compressor 1 is not limited to a configuration in which a main switch 70 and a start switch 72 are provided separately, and various configurations can be adopted as long as they can turn the accessory (main switch) on and off and can also turn the starter motor on and off. The switch for turning the accessory on and off and the starter motor on and off may be configured as a known key switch that can be switched from the OFF position to the ON position (accessory position) and further to the start position in which the engine starter motor is rotated by inserting and turning a key.

[0085] In addition, the engine-driven compressor 1 of the present invention is provided with a temperature sensor 65 that detects the oil temperature in the compressor main body 40 (Figures 1 and 4), and the controller 30 monitors changes in the oil temperature in the compressor main body 40 based on the detection signal from this temperature sensor 65.

[0086] 〔controller〕 The engine-driven compressor 1 of the present invention configured as described above is provided with a controller 30 which is an electronic control device that controls the operation of the first solenoid valve 23, the second solenoid valve 24, and the three-way solenoid valve 27 based on the operation of the switches described above, the change in oil temperature in the compressor body 40 detected by the temperature sensor 65, and the count of the built-in timer 36.

[0087] This controller 30 executes the following control based on the operating states of the above-mentioned switches 70, 72, the discharge temperature of the compressor main body 40 detected by the temperature sensor 65, and the count of the timer 36.

[0088] (1) Starting operation When an operator turns the main switch 70 to the "ON" position, electricity is supplied to each part of the engine-driven compressor 1, and the controller 30 starts up.

[0089] Thereby, the controller 30 receives the detected temperature from the temperature sensor 65 that detects the oil temperature in the compressor body 40, and determines whether the oil temperature is below 0°C.

[0090] Furthermore, if the oil temperature is higher than 0°C, the controller 30 determines whether the oil temperature is below 60°C, and according to a pre-stored correspondence, if it is below 60°C, it sets the elapse of a cold operation time (for example, 180 seconds from engine start) as the warm-up operation cancellation condition, and if the oil temperature of the compressor body exceeds 60°C, it sets the elapse of a warm-up operation time (for example, 60 seconds from engine start) as the warm-up operation cancellation condition.

[0091] Thereafter, when the start switch 72 is pressed and held to start the engine, if the oil temperature exceeds 0°C, the controller 30 does not energize the starting control flow path solenoid valve 53 (NC type in this embodiment) and keeps the starting control flow path 51 blocked, and while keeping the first solenoid valve 23 de-energized (OFF), i.e., in the open state, energizes (ON) the second solenoid valve 24 to open it, and in this state rotates the starter motor to start the engine (see Figures 5(A) and "ENG start" in Figure 6).

[0092] In this way, by connecting the closing valve pressure chamber 113 of the intake regulating valve 11 to the receiver tank 60 via the bypass passage 20 (first and second bypass passages 21, 22), the control of the intake regulating valve 11 by the pressure regulating valve 13 is disabled, and it is possible to cause the intake regulating valve 11 to perform a closing operation even if the pressure in the receiver tank 60 is lower than the operating pressure of the pressure regulating valve 13.

[0093] As a result, when the pressure inside the receiver tank 60 rises due to the rotation of the compressor body 40 and exceeds the operating pressure of the intake regulating valve 11, the intake regulating valve 11 closes.

[0094] As a result, the engine warm-up operation begins in a no-load state with the intake control valve 11 closing the intake port 41 of the compressor body 40.

[0095] In addition, in a configuration having the three-way solenoid valve 27 shown in Figures 1 and 5, when the engine is started, the controller 30 switches the three-way solenoid valve 27 to a position that connects the auxiliary pressure chamber 114 of the intake control valve 11 to the intake passage 115 on the secondary side of the valve seat 115a (a position that connects ports CA).

[0096] As a result, when the engine starts up, the compressor body 40 begins to rotate and the pressure in the intake passage 115 on the secondary side of the valve seat 115a becomes negative, so that the auxiliary pressure receiving chamber 114 of the intake control valve 11 also becomes negative, thereby enabling the closing operation of the intake control valve 11 to be completed more quickly when the engine is started.

[0097] (2) Discharge pressure increase process When the controller 30 determines based on the count of the timer 36 that a predetermined time X (10 seconds in this embodiment, as an example) has elapsed after the engine has been started, it starts to supply electricity (ON) to the first solenoid valve 23 to close the first solenoid valve 23, and starts to supply electricity (ON) to the three-way solenoid valve 27 to switch the three-way solenoid valve 27 to a position that connects the auxiliary pressure receiving chamber 114 of the intake control valve 11 to the intake passage 115 on the primary side of the valve seat 115a (a position that connects ports CB) (see "Discharge pressure increase process" in Figure 5(B) and Figure 6).

[0098] As a result, the negative pressure in the auxiliary pressure chamber 114 is eliminated, and the introduction of compressed gas that had been introduced from the receiver tank 60 to the closed-valve pressure chamber 113 of the intake control valve 11 via the first bypass passage 21 is stopped, thereby reducing the flow rate of compressed gas introduced into the closed-valve pressure chamber 113, thereby lowering the pressure in the closed-valve pressure chamber.

[0099] As a result, the intake control valve 11 changes from a fully closed state to a slightly open state at a specified degree less than fully open, and the compressor main body 40 begins to take in air, causing the pressure in the receiver tank 60, which was, for example, about 0.1 MPa in gauge pressure, to rise to the fuel supply start pressure (for example, about 0.35 MPa in gauge pressure) through this discharge pressure increase process (see "STEP 2" in Figure 6(B)).

[0100] In the illustrated embodiment, the bypass passage 20 is formed by two passages consisting of the first and second bypass passages 21, 22, and one of these passages (the first bypass passage 21) is blocked to reduce the flow rate of compressed gas introduced into the closed valve pressure chamber 113 of the intake control valve 11, thereby increasing the pressure in the receiver tank 60 to the refueling start pressure.

[0101] In contrast to this, for example, the bypass flow path 20 may be configured with three or more parallel flow paths, with at least one parallel flow path remaining, and the other parallel flow paths being blocked one by one at predetermined time intervals, thereby gradually increasing the pressure to a predetermined oil supply start pressure.

[0102] In this case, even if the fuel supply start pressure is set to a higher pressure, it is possible to prevent the engine from stopping (stalling).

[0103] (3) Normal operation The controller 30 sets the elapse of the warm-up operation time (cold operation time or warm operation time) set based on the oil temperature at startup as the warm-up operation cancellation condition, and when this warm-up temperature cancellation condition is met, it closes the second solenoid valve 24 by stopping (OFF) the flow of electricity to the second solenoid valve 24, thereby blocking the second bypass flow path 22 (see Figure 5 (C) and "Warm-up operation cancellation" in Figure 6).

[0104] As a result, the introduction of compressed gas from the receiver tank 60 to the closed valve pressure receiving chamber 113 of the intake control valve 11 via the second bypass passage 22 is stopped.

[0105] In this way, the bypass passage 20 (21, 22) is completely blocked, and the opening and closing operation of the intake control valve 11 is controlled by the pressure control valve 13 provided in the control passage 12, and the system transitions to normal operation.

[0106] When transitioning to normal operation, the pressure in the receiver tank 60 is at the fuel supply start pressure, which is a predetermined pressure lower than the rated pressure, so the pressure regulating valve 13 closes the control passage 12 and no compressed gas in the receiver tank 60 is introduced into the closed valve pressure chamber 113 of the intake regulating valve 11, so that the intake regulating valve 11 is fully opened and the compressor main body 40 begins full load operation.

[0107] In this manner, in the configuration of the present invention, the pressure in the receiver tank 60 is raised to a predetermined oil supply start pressure by the above-mentioned discharge pressure increase process before switching to normal operation, and the amount of oil supplied to the compressor main body 40 is increased, thereby making it possible to effectively prevent abnormal increases in the discharge temperature due to insufficient supply of lubricating oil when switching to normal operation and the compressor main body 40 begins full-load operation.

[0108] [Control when oil temperature is below 0℃] The above describes the warm-up operation when the oil temperature exceeds 0°C when the main switch is turned ON. However, when the oil temperature is below 0°C, the controller 30 can be configured to control each part as follows.

[0109] (1) Starting operation When the oil temperature is below 0°C, if the start switch 72 is pressed and held to start the engine, the controller 30 energizes the solenoid valve 53 for the starting control flow path to open the starting control flow path 51, and while keeping the first solenoid valve 23 de-energized (OFF), i.e., in the open state, energizes (ON) the second solenoid valve 24 to open it, and in this state rotates the starter motor to start the engine (see Figures 7(A) and "ENG start" in Figure 8).

[0110] In this way, by connecting the closed valve pressure chamber 113 of the intake regulating valve 11 to the receiver tank 60 via the bypass passage 20 (first and second bypass passages 21, 22), even if the receiver tank 60 and the closed valve pressure chamber 113 of the intake regulating valve 11 are connected via the starting control passage 51 by opening the starting control passage solenoid valve 53, the control of the intake regulating valve 11 by the starting pressure regulating valve 52 is disabled, and it is possible to cause the intake regulating valve 11 to perform a closing operation even if the pressure in the receiver tank 60 does not meet the operating pressure of the starting pressure regulating valve 52.

[0111] As a result, when the pressure inside the receiver tank 60 rises slightly due to the rotation of the compressor body 40 and exceeds the operating pressure of the intake regulating valve 11, the intake regulating valve 11 closes.

[0112] As a result, the engine warm-up operation begins in a no-load state with the intake control valve 11 closing the intake port 41 of the compressor body 40.

[0113] In addition, in a configuration in which a three-way solenoid valve 27 is provided, during this startup operation, the controller 30 switches the three-way solenoid valve 27 to a position that connects the auxiliary pressure chamber 114 of the intake control valve 11 to the intake passage 115 on the secondary side of the valve seat 115a (a position that connects ports CA), which is the same as the operation when the oil temperature is 0°C or higher as described above.

[0114] (2) Discharge pressure increase process After the engine has started and a predetermined time (10 seconds in this embodiment as an example) has elapsed, the controller starts to supply electricity (ON) to the first solenoid valve to close it, and starts to supply electricity (ON) to the three-way solenoid valve 27 to switch the three-way solenoid valve 27 to a position that connects the auxiliary pressure receiving chamber 114 of the intake control valve 11 to the intake passage 115 on the primary side of the valve seat 115a (a position that connects ports CB) (see Figure 7(B) and "Discharge pressure increase processing" in Figure 8).

[0115] As a result, the flow rate of compressed gas introduced into the closed-valve pressure chamber 113 of the intake control valve 11 decreases, causing the pressure in the closed-valve pressure chamber 113 to drop, and the intake control valve 11, which was in a fully closed state, opens slightly to a predetermined opening degree less than fully open, and the compressor main body 40 begins to take in air, causing the pressure in the receiver tank 60 to rise to the fuel supply start pressure (see "STEP 2" in Figure 8(B)).

[0116] (3) Control by start-up pressure regulator After a predetermined time Y (30 seconds, for example, in this embodiment) has elapsed since the execution of the above-mentioned discharge pressure increase process, the controller 30 stops (turns off) the supply of electricity to the second solenoid valve 24 provided in the second bypass flow path 22, and closes the second solenoid valve 24 (see Figure 7(C)).

[0117] As a result, the introduction of compressed gas from the receiver tank 60 to the closed-valve pressure chamber 113 via the bypass passage 20 (21, 22) is completely stopped, and the opening and closing operation of the intake control valve 11 is transferred to control by the start-up pressure control valve 52 provided in the start-up control passage 51.

[0118] The operating pressure of the starting pressure regulating valve 52 is adjusted so that the pressure in the receiver tank 60 opens when it is equal to or above the starting unloading pressure, which is a predetermined higher pressure than the refueling start pressure and a predetermined lower pressure than the rated pressure.

[0119] Furthermore, even if the opening and closing operation of the intake regulating valve 11 is transferred to the control of the starting pressure regulating valve 52 due to the blockage of the bypass flow path 20 (21, 22), since the pressure in the receiver tank 60 at this point is lower than the starting unload pressure, when the bypass flow path 20 is blocked, the introduction of compressed gas into the closed valve pressure chamber 113 of the intake regulating valve 11 is stopped and the intake regulating valve 11 becomes fully open.

[0120] As a result, full-load operation of the compressor body 40 begins, and the pressure in the receiver tank 60 rises (see "STEP 3" in FIG. 8(B)).

[0121] When the pressure in the receiver tank 60 rises above the starting unload pressure, the starting pressure regulating valve 52 opens, compressed gas from the receiver tank 60 is introduced into the closed valve pressure chamber 113 of the intake regulating valve 11, the intake regulating valve 11 closes, and the pressure in the receiver tank 60 is maintained near the starting unload pressure.

[0122] After a predetermined time (for example, 140 seconds in this embodiment) has elapsed since the second solenoid valve 24 was closed, the controller 30 stops (turns off) the power supply to the start-up control flow path solenoid valve 53 and closes the start-up control flow path 51.

[0123] As a result, the opening and closing control of the intake regulating valve 11 by the starting pressure regulating valve 52 ends, and the opening and closing control of the intake regulating valve is performed by the pressure regulating valve 13 provided in the control flow passage 12, and a transition is made to normal control.

[0124] In this way, when the engine-driven compressor 1 is started up at a predetermined low oil temperature (for example, below 0°C), after the bypass passage 20 is blocked, control is transferred to the start-up pressure regulating valve 52 provided in the start-up control passage 51, so that the pressure in the receiver tank 60 can be increased in multiple stages up to the start-up unload pressure, which is a pressure higher than the oil supply start pressure.

[0125] As a result, even if the outside air temperature is low and the viscosity is increased, and therefore it is not possible to ensure a sufficient supply of lubricating oil to the compressor body 40 simply by raising the pressure in the receiver tank 60 to the oil supply start pressure, it is possible to supply a sufficient amount of lubricating oil to the compressor body 40 before switching to normal operation.

[0126] In the above explanation, a configuration example in which a single start-up control flow path 51 is provided is described, but as shown as a modified example in Figure 1, two or more start-up control flow paths 51a, 51b, ... 51z may also be provided.

[0127] In this case, startup pressure regulating valves 52a, 52b....52z are provided in the startup control flow paths 51a, 51b....51z, respectively, and the startup pressure regulating valves 52a, 52b....52z have different operating pressures.

[0128] In addition, in each of the start-up control flow paths 51a, 51b...51z, start-up control flow path solenoid valves 53a, 53b...53z, which are solenoid opening / closing valves, are provided in series with the start-up pressure regulating valves 52a, 52b...52z, respectively.

[0129] The controller 30 may be configured to close the starting control flow path solenoid valves 53a provided in the starting control flow path 51a in which the starting pressure regulating valve 52a having the lowest operating pressure is provided, in sequence at predetermined time intervals after blocking of the bypass flow path 20, and to close the starting control flow path solenoid valve 53z provided in the starting control flow path 51z in which the starting pressure regulating valve 52z having the highest operating pressure is provided, when the warm-up operation end condition is satisfied, thereby enabling the pressure in the receiver tank 60 to be increased in multiple stages. [Explanation of symbols]

[0130] 1. Engine-driven compressor 10. Intake adjustment device 11 Intake control valve 111 Body (valve box) 112 Airtight chamber (cylinder) 113 Closed valve pressure chamber 114 Auxiliary pressure chamber (spring chamber) 114a Spring 115 Suction flow path 115a Valve seat 116 Valve body 116a,116a' Valve stem 116b Spring 117 Sleeve 118 End plate 119 Pressure receiving body (piston) 119a Valve stem 12 Control Channel 13 Pressure Regulating Valve 14 Relief Channel 15 Aperture 20 Bypass flow path 21 First bypass flow path (parallel flow path) 22 Second bypass flow path (parallel flow path) 23 First solenoid valve (parallel flow path solenoid valve) 24 Second solenoid valve (parallel flow path solenoid valve) 25 Common flow path 26 Block manifold 27 Three-way solenoid valve 28a~28c Flow path 30 Controller (control device) 36 Timer 40 Compressor body 41 Air Intake 51 (51a, 51b, 51z) Start control flow path 52 (52a, 52b, 52z) Starting pressure adjusting valve 53 (53a, 53b, 53z) Solenoid valve for start-up control flow passage 60 Receiver Tank 61 Pressure Regulating Valve 62 Discharge flow path 63 Oil cooler 64 Oil supply passage 65 Temperature Sensor 66 Service valve 70 Main switch 72 Start switch 300 Engine-driven compressor 310 Intake adjustment device 311 Intake control valve 312 Control Channel 313 Pressure Regulating Valve 314 Relief Channel 315 Aperture 316 Unloader regulator 320 Starting Load Reduction Device 321 Bypass flow path 325 Bypass valve 340 Compressor body 341 Air Intake 350 Engine 360 Receiver Tank 363 Oil Cooler 364 Oil supply passage 366 Oil Separator 367 Oil Filter

Claims

1. An operation control method for an engine-driven compressor including an engine, an oil-cooled compressor body driven by the engine, a receiver tank that introduces a gas-liquid mixture of compressed gas and lubricating oil discharged from the compressor body and separates the compressed gas and the lubricating oil, and supplies the separated lubricating oil to the compressor body by utilizing internal pressure, an intake regulating valve that controls intake to the compressor body, a control flow path that communicates between a closing valve pressure receiving chamber of the intake regulating valve and the receiver tank, and a pressure regulating valve that controls opening and closing of the intake regulating valve by opening the control flow path when the pressure in the receiver tank is equal to or higher than a predetermined rated pressure and closing the control flow path when the pressure in the receiver tank is below the rated pressure, The control of the intake control valve by the pressure control valve is disabled, and the intake control valve is closed when the engine is started to start a warm-up operation, and after starting the engine, before a predetermined warm-up operation completion condition is satisfied, a discharge pressure increase process is performed in which the pressure in the receiver tank is increased to a fuel supply start pressure, which is a predetermined pressure lower than the rated pressure, by opening the intake control valve at a predetermined opening degree less than full opening, a warm-up operation end condition for ending the warm-up operation and a transition to a normal operation in which the intake control valve is controlled by the pressure control valve when the warm-up operation end condition is satisfied.

2. providing a bypass flow passage that bypasses the pressure regulating valve and communicates between the receiver tank and the closed valve pressure receiving chamber of the intake regulating valve, and starting the engine in a state in which the receiver tank and the closed valve pressure receiving chamber of the intake regulating valve are communicated through the bypass flow passage, thereby disabling control of the intake regulating valve by the pressure regulating valve and closing the intake regulating valve as soon as the engine is started; The discharge pressure increasing process is performed by throttling a flow rate of compressed gas introduced into the closed valve pressure receiving chamber of the intake control valve through the bypass flow path, 2. The method for controlling an operation of an engine-driven compressor according to claim 1, further comprising the step of: closing the bypass passage to terminate the warm-up operation and transition to a normal operation in which the intake control valve is controlled by the pressure control valve.

3. a starting control flow passage that bypasses the pressure regulating valve and communicates between a closing valve pressure receiving chamber of the intake regulating valve and the receiver tank; a starting pressure regulating valve that opens the starting control passage when the pressure in the receiver tank is equal to or higher than a starting unloading pressure that is a predetermined higher pressure than the fuel supply start pressure and a predetermined lower pressure than the rated pressure, and closes the starting control passage when the pressure in the receiver tank is lower than the starting unloading pressure, thereby controlling the opening and closing operation of the intake regulating valve; After the discharge pressure increasing process, before the warm-up operation completion condition is satisfied, the intake control valve is controlled by the starting pressure control valve, 2. The method for controlling an operation of an engine-driven compressor according to claim 1, wherein, when the warm-up operation termination condition is satisfied, the control of the intake control valve by the starting pressure control valve is terminated and the warm-up operation is terminated, and the operation transitions to the normal operation in which the intake control valve is controlled by the pressure control valve.

4. a bypass flow passage is provided which bypasses the pressure regulating valve and communicates between the receiver tank and the closed valve pressure receiving chamber of the intake regulating valve, and the engine is started in a state in which the receiver tank and the closed valve pressure receiving chamber of the intake regulating valve are communicated through the bypass flow passage, thereby disabling control of the intake regulating valve by the pressure regulating valve and the starting pressure regulating valve, and closing the intake regulating valve as the engine is started; The discharge pressure increasing process is performed by throttling a flow rate of compressed gas introduced into the closed valve pressure receiving chamber of the intake control valve through the bypass flow path, 4. The method for controlling an operation of an engine-driven compressor according to claim 3, wherein the bypass passage is closed and control of the intake control valve by the starting pressure control valve is started after a predetermined time has elapsed since the discharge pressure increase process.

5. 5. The method for controlling an engine-driven compressor according to claim 1, wherein the discharge pressure increasing process is performed while increasing the opening of the intake control valve in a stepwise manner.

6. A plurality of the start-up control flow paths are provided, the start-up pressure regulating valve is provided in each of the start-up control flow paths, and the operating pressure of each of the start-up pressure regulating valves is set to a different pressure; 4. The method for controlling an operation of an engine-driven compressor according to claim 3, wherein the control of the intake control valve by the starting pressure control valve, which is performed after the discharge pressure increase process and until the warm-up operation completion condition is satisfied, is performed by switching sequentially from the starting pressure control valve having the lowest operating pressure to the starting pressure control valve having the highest operating pressure at predetermined time intervals.

7. an engine-driven compressor including an engine, an oil-cooled compressor body driven by the engine, a receiver tank which introduces a gas-liquid mixture of compressed gas and lubricating oil discharged from the compressor body and separates the compressed gas and the lubricating oil, and supplies the separated lubricating oil to the compressor body by utilizing internal pressure, an intake regulating valve which controls intake to the compressor body, a control flow path which communicates between a closing valve pressure receiving chamber of the intake regulating valve and the receiver tank, and a pressure regulating valve which controls opening and closing of the intake regulating valve by opening the control flow path when the pressure in the receiver tank is equal to or higher than a predetermined rated pressure and closing the control flow path when the pressure in the receiver tank is below the rated pressure, a bypass flow passage that bypasses the pressure regulating valve and communicates between the receiver tank and the closed valve pressure receiving chamber of the intake regulating valve; a flow area changing device that changes the flow area of ​​the bypass flow path; A control device is provided for controlling the flow path area changing device, The control device controls the flow path area changing device, when the engine is started, the flow passage area of ​​the bypass flow passage is maximized, and the intake control valve is closed simultaneously with the start of the engine, thereby starting a warm-up operation; After the engine is started, before a predetermined warm-up operation completion condition is satisfied, a discharge pressure increase process is performed in which the pressure in the receiver tank is increased to a fuel supply start pressure, which is a predetermined lower pressure than the rated pressure, by reducing a flow passage area of ​​the bypass passage and opening the intake control valve to a predetermined opening degree less than full opening, and when the warm-up operation termination condition is satisfied, the bypass passage is closed to terminate the warm-up operation, and a transition is made to normal operation in which the intake control valve is controlled by the pressure control valve.

8. an engine-driven compressor including an engine, an oil-cooled compressor body driven by the engine, a receiver tank which introduces a gas-liquid mixture of compressed gas and lubricating oil discharged from the compressor body and separates the compressed gas and the lubricating oil, and supplies the separated lubricating oil to the compressor body by utilizing internal pressure, an intake regulating valve which controls intake to the compressor body, a control flow path which communicates between a closing valve pressure receiving chamber of the intake regulating valve and the receiver tank, and a pressure regulating valve which controls opening and closing of the intake regulating valve by opening the control flow path when the pressure in the receiver tank is equal to or higher than a predetermined rated pressure and closing the control flow path when the pressure in the receiver tank is below the rated pressure, a bypass flow passage and a starting control flow passage that bypass the pressure regulating valve and communicate between the receiver tank and a closing valve pressure receiving chamber of the intake regulating valve; a flow area changing device that changes the flow area of ​​the bypass flow path; a starting pressure regulating valve provided in the starting control flow path, which opens when the discharge side pressure of the compressor body is equal to or higher than a starting unloading pressure that is a predetermined lower pressure than the rated pressure, and closes when the discharge side pressure of the compressor body is lower than the starting unloading pressure; a start-up control flow passage solenoid valve provided in the start-up control flow passage and connected in series to the start-up pressure regulating valve; a control device for controlling the flow path area changing device and the start control flow path solenoid valve; The control device includes: When starting the engine, the starting control flow passage solenoid valve is opened, and the flow passage area change device is operated to maximize the flow passage area of ​​the bypass flow passage, thereby starting the engine and closing the intake control valve to start a warm-up operation; after starting the engine, before a predetermined warm-up operation completion condition is satisfied, the flow path area change device is controlled to reduce the flow path area of ​​the bypass flow path, and the intake control valve is opened to a predetermined opening degree less than full opening, thereby performing a discharge pressure increase process for increasing the pressure in the receiver tank to a fuel supply start pressure which is a predetermined pressure lower than the starting unload pressure, after the discharge pressure increasing process, before the warm-up operation end condition is satisfied, the bypass passage is closed and control of the intake control valve is shifted to the start pressure control valve, when the warm-up operation termination condition is satisfied, the solenoid valve for the starting control flow path is closed to terminate control of the intake control valve by the starting pressure control valve, and the warm-up operation is terminated, and a transition is made to normal operation in which the intake control valve is controlled by the pressure control valve.

9. the bypass flow path is formed as a collection of a plurality of parallel flow paths arranged in parallel, and a parallel flow path solenoid valve is provided in each of the parallel flow paths, thereby making the parallel flow path solenoid valve the flow path area changing device; The control device When the engine is started, all of the parallel flow path solenoid valves are opened, 9. The engine-driven compressor according to claim 7, wherein the discharge pressure increasing process is performed by closing at least one of the parallel flow path solenoid valves in sequence at predetermined time intervals.

10. A plurality of the start-up control flow paths are provided, and each of the start-up control flow paths is provided with a start-up control flow path solenoid valve for opening and closing the start-up control flow path, and a start-up pressure regulating valve having a different operating pressure, The control device When starting the engine, all of the starting control passage solenoid valves are opened, 9. The engine-driven compressor according to claim 8, characterized in that after the bypass flow passage is blocked, the startup control flow passage solenoid valves provided in the startup control flow passage in which the startup pressure adjustment valve having the lowest operating pressure is provided are successively closed at predetermined time intervals, and when the warm-up operation completion condition is satisfied, the startup control flow passage solenoid valve provided in the startup control flow passage in which the startup pressure adjustment valve having the highest operating pressure is provided is closed.

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