JP2020180557A - Capacity control device of engine driving compressor - Google Patents

Abstract

To provide an engine driving compressor with low fuel consumption and excellent startability.SOLUTION: A pressure receiving chamber 61 of a speed regulator 60 is communicated with a secondary side of a pressure regulator 70 connected to a receiver tank 32 on a primary side, and a valve closing pressure receiving chamber 51 of an intake control valve 50 is serially communicated with the pressure receiving chamber via a throttle 91. Other end 84b of a bypass flow path 84 bypassing a pressure regulator and communicating one end 84a with the receiver tank 32 is parallely communicated with the pressure receiving chamber of the speed regulator and the valve closing pressure receiving chamber of the intake control valve. An on-off valve 41 is provided to the bypass flow path 84 to form a starting load loosening mechanism 4. At the time of closing the on-off valve at which a capacity is controlled by compressed gas passing through the pressure regulator, and at the time of shifting to a non-load operation, after the rotation speed of the engine is reduced, fuel consumption improves by closing an intake port 21. At the starting time at which the capacity is controlled by the compressed gas passing through the bypass flow path 84, after the intake port of a compressor body is closed, the rotation speed of the engine is reduced and startability improves.SELECTED DRAWING: Figure 5

Description

The present invention relates to a capacity control device for an engine-driven compressor. More specifically, the present invention controls intake control for controlling the intake amount of the compressor body and control of engine rotation speed according to the consumption amount of compressed gas on the consumption side. It is related to the capacity control device that controls the speed.

An engine-driven compressor that drives the compressor body with an engine is widely used as a source of compressed gas such as compressed air in outdoor work such as civil engineering work sites and construction sites where it is difficult to secure a power source. ..

As an example of such an engine-driven compressor, FIG. 7 shows a configuration example of the engine-driven compressor 100 described in Patent Document 1 described later.

In this engine-driven compressor 100, in addition to the compressor body 120 and the engine 130 described above, a receiver tank that stores the compressed gas discharged together with the lubricating oil from the compressor body 120 and separates the compressed gas and the lubricating oil. The 132 is provided so that the compressed gas after the lubricating oil is separated in the receiver tank 132 can be supplied to the consumption side to which an air work machine or the like (not shown) is connected.

Then, in the engine-driven compressor 100 of FIG. 7, the intake air of the compressor main body 120 is taken in accordance with the pressure in the receiver tank 132 so that the compressed gas having a stable pressure can be supplied to the consumption side. The capacity control device 105 is provided to control the rotation speed of the engine 130 as well as to control the engine 130.

As such a capacity control device 105, the engine drive compressor 100 shown in FIG. 7 has a butterfly valve 151 that opens and closes the intake port 121 of the compressor main body 120, and an unloader that closes the butterfly valve 151 in response to the introduction of compressed gas. It is equipped with an intake control valve 150 composed of a regulator 152, a speed regulator 160 that moves the governor lever 135 of the engine 130 to the low speed side in response to the introduction of compressed gas, and a pressure regulator 170 that is communicated with the receiver tank 132. A capacitance control device 105 having a configuration in which the control flow path 181 communicated with the secondary side of 170 is branched and one flow path 181a is connected to the speed regulator 160 and the other flow path 181b is connected to the unloader regulator 152 in parallel. It has.

As a result, in the engine drive compressor 100 shown in FIG. 7, when the pressure in the receiver tank 132 becomes less than the operation start pressure of the pressure regulator 170 due to the consumption of compressed gas on the consumption side, the pressure regulator 170 closes. No working pressure is introduced into either the pressure receiving chamber of the unloader regulator 152 or the pressure receiving chamber of the speed regulator 160, the intake control valve 150 opens the intake port 121 of the compressor body 120 fully, and the speed regulator 160 is the engine. The governor lever 135 of 130 is moved to a high speed position to start full load operation.

Then, when the pressure in the receiver tank 132 rises above the operation start pressure of the pressure regulator 170 due to the stop of consumption of compressed gas on the consumption side, the pressure regulator 170 starts to open and the pressure receiving chamber of the unloader regulator 152 and the speed regulator The introduction of the operating pressure into the pressure receiving chamber of 160 is started, the intake control valve 150 throttles the intake port 121 of the compressor main body 120 according to the pressure of the introduced compressed gas, and the speed regulator 160 sets the rotation speed of the engine 130. To reduce.

After that, when the pressure in the receiver tank 132 rises above the predetermined no-load operation start pressure, such as when the consumption of compressed gas continues to stop, the pressure regulator 170 is fully opened, and the compressor main body is operated by the intake control valve 150. When the intake port 121 of 120 is closed, the speed regulator 160 shifts to no-load operation at a low speed of the engine 130, and the consumption of compressed gas on the consuming side is restarted, the pressure in the receiver tank 132 drops. The above operation is repeated.

In this way, the capacity control device 105 performs intake control of the compressor main body 120 and speed control of the engine 130 according to the consumption amount of the compressed gas on the consumption side during operation of the engine drive compressor 100, thereby performing the consumption side. It is configured to be able to supply a compressed gas with a stable pressure.

In the engine drive compressor 100, since the compressor main body 120 is connected to the engine 130, the rotational resistance of the compressor main body 120 is always applied to the engine 130 as a load, but the operating state is unstable. When a load is applied to the engine 130 immediately after starting, the engine is easily stopped.

Therefore, the capacity control device 105 described in Patent Document 1 includes the primary side and the secondary side of the pressure regulator 170 for the purpose of reducing the load received by the engine 130 from the compressor main body 120 when the engine drive compressor 100 is started. A starting load reducing mechanism 104 including a bypass flow path 184 communicating with the next side and an on-off valve 141 for opening and closing the bypass flow path 184 is provided.

As a result, when the engine drive compressor 100 is started with the on-off valve 141 operated to open the bypass flow path 184, the bypass flow path 184 bypasses the pressure regulator 170 and the bypass flow path 184 unloads the compressed gas in the receiver tank 132. It was introduced into the pressure receiving chamber of 152 and the pressure receiving chamber of the speed regulator 160, respectively. As a result, the starting operation of the engine drive compressor 100 was performed by closing the intake port 121 of the compressor main body 120 and reducing the rotation speed of the engine 130. , It can be performed in the state of no-load operation (see FIG. 5 of Patent Document 1).

JP-A-2002-168177

In the configuration of the capacitance control device 105 described in Patent Document 1 described above, the control flow path 181 communicating with the secondary side of the pressure regulator 170 is branched, and one flow path 181a is used as the pressure receiving chamber of the speed regulator 160. A configuration is adopted in which the other flow path 181b communicates with the pressure receiving chamber of the unloader regulator 152 in parallel.

As a result, when the pressure in the receiver tank 132 rises and shifts from full-load operation to no-load operation, the introduction of operating pressure into the pressure receiving chamber of the unloader regulator 152 and the pressure receiving chamber of the speed regulator 160 is started almost at the same time. Therefore, it is possible to reduce the rotation speed of the engine 130 and close the intake port 121 of the compressor main body 120 at substantially the same time.

However, from the viewpoint of improving the fuel efficiency of the engine-driven compressor 100, when shifting from full-load operation to no-load operation, the rotation speed of the engine 130 is first reduced, and then the intake port 121 of the compressor body 120 is closed. It is more advantageous to have a configuration that operates.

On the other hand, in order to reduce the rotation speed of the engine 130 and operate the intake control valve 150 in the order described above, the device configuration becomes complicated when large-scale components are added or electronic control is adopted. Not only that, the manufacturing cost of the capacity control device increases due to the increase in the number of parts and the addition of an expensive electronic control device.

Therefore, in order to solve the above problems, the inventors of the present invention have conducted extensive research, and as a result, full-load operation is performed by changing the pipe connection without adding a large-scale component or electronically controlling it. We succeeded in developing a new capacity control device that first slows down the engine speed and then closes the intake control valve when shifting from to no-load operation.

However, with the newly developed capacity control device, when shifting from full-load operation to no-load operation, fuel efficiency is improved by reducing the engine speed prior to the valve closing operation of the intake control valve. However, the configuration of this capacitance control device follows the capacitance control device 105 described with reference to FIG. 7, and a bypass flow path 184 that bypasses the pressure regulator 170 and an on-off valve that opens and closes the bypass flow path 184. When the starting load reducing mechanism 104 composed of 141 is provided, even at the time of starting by opening the bypass flow path 184, the intake control valve 150 is set to the compressor main body after the rotation speed of the engine 130 is reduced as in the normal operation. The intake port 121 of 120 will be closed.

As a result, the rotation speed of the engine 130, which is in an unstable state at the time of starting, is reduced while the intake port 121 of the compressor body 120 is kept open and a high load is applied, and then the compressor body 120 Since the intake port 121 is closed to reduce the load, a new problem has arisen in which the engine 130 stalls when the rotation speed is reduced.

The present invention has been made to solve these problems, and the mechanical capacity control device can be operated from full load operation by changing the piping configuration without significant addition of component parts or electronic control. The fuel efficiency of the engine-driven compressor can be improved by modifying the intake control valve so that it can be closed after the engine speed is reduced when shifting to no-load operation. The first object is to provide a capacity control device.

Further, as described above, the present invention has a configuration in which the intake control valve closes after the engine speed is reduced when shifting from full-load operation to no-load operation during normal operation. Occasionally, at the same time as the engine speed decreases, or prior to the engine speed decrease, the intake control valve is closed to reduce the load, which is contrary to the operation during normal operation. A second object is to provide a capacity control device provided with a starting load reducing mechanism.

The means for solving the problem are described below together with the reference numerals used in the embodiment of the invention. This reference numeral is for clarifying the correspondence between the description of the claims and the description of the form for carrying out the invention, and needless to say, it is used in a restrictive manner in the interpretation of the technical scope of the present invention. It is not something that can be done.

In order to achieve the above object, the capacity control device 5 of the engine drive compressor 1 of the present invention is
In an engine-driven compressor 1 having an engine and a compressor main body 2 driven by the engine, and having a supply flow path 3 for supplying the compressed gas discharged by the compressor main body 2 to the consumption side.
A pressure-receiving valve-type intake control valve 50 that controls the opening and closing of the intake port 21 of the compressor body 2, a speed regulator 60 that reduces the rotation speed of the engine in response to a pressure increase in the pressure receiving chamber 61, and the supply flow. When the pressure on the primary side connected to the passage 3 (the receiver tank 32 constituting the supply flow path 3 in the illustrated example) becomes equal to or higher than a predetermined operation start pressure, the valve is opened to release the compressed gas in the supply flow path 3. A pressure regulator 70 to be introduced on the secondary side is provided.
The first flow path 81 that communicates the secondary side of the pressure regulator 70 with the pressure receiving chamber 61 of the speed regulator 60 and the pressure receiving chamber 61 of the speed regulator 60 are connected to the closed pressure receiving chamber of the intake control valve 50. A second flow path 82 communicating with the throttle 91 via a throttle 91 is provided in 51, and the pressure receiving chamber 61 of the speed regulator 60 and the valve closing pressure receiving chamber 51 of the intake control valve 50 are provided on the secondary side of the pressure regulator 70. It is characterized in that it communicates in series (claim 1; see FIG. 1).

In the capacitance control device 5 having the above configuration, one end 84a is further communicated to the supply flow path 3 (in the illustrated example, the receiver tank 32 constituting the supply flow path 3) by bypassing the pressure regulator 70. The other end 84b of the speed regulator 60 receives pressure from the speed regulator 60 via a flow path (82, 85, 86) communicated with the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50. A starting load reducing mechanism 4 including a bypass flow path 84 that is communicated in parallel with the chamber 61 and the valve closing pressure receiving chamber 51 of the intake control valve 50, and an on-off valve 41 that opens and closes the bypass flow path 84 is provided. (Claim 2; see FIGS. 5 and 6).

The starting load reducing mechanism 4 having the above configuration communicates the other end 84b of the bypass flow path 84 with the second flow path 82 on the secondary side of the throttle 91, and passes through the second flow path 82. The other end 84b of the bypass flow path 84 may be communicated in parallel with the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50, respectively (claim 3; (See FIG. 5).

Further, in the capacitance control device 5 of the present invention, the secondary of the throttle 91 is connected to the second flow path 82 that communicates the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50. A branch flow path 83 branched on the side may be provided, a throttle 92 may be provided in the branch flow path 83, and the branch flow path 83 may be opened to the atmosphere (see claim 4; FIGS. 1, 4 to 6).

In this way, a branch flow path 83 branched from the second flow path 82 communicating the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50 on the secondary side of the throttle 91 is provided, and the branch is provided. In the configuration in which the flow path 83 is provided with the throttle 92 and the branch flow path 83 is open to the atmosphere, two flow paths 85 and 86 branched from the other end 84b of the bypass flow path 84 via, for example, a manifold 95 are provided. The other end 84b of the bypass flow path 84 is communicated with the pressure receiving chamber 61 of the speed regulator 60 via one of the branched flow paths 85, and the bypass flow path 84 is communicated through the other branched flow path 86. The other end 84b of the above is communicated with the closed valve pressure receiving chamber 51 of the intake control valve 50.
A check valve 97 that allows the flow of compressed gas toward the pressure receiving chamber 61 of the speed regulator 60 is provided in one of the flow paths 85, and the intake control valve 50 is closed in the other flow path 86. A check valve 98 that allows the flow of compressed gas toward the valve pressure receiving chamber 51 may be provided (claim 5; see FIG. 6).

With the configuration of the present invention described above, the capacity control device 5 of the engine drive compressor 1 of the present invention was able to obtain the following remarkable effects.

In the capacitance control device 5 of the present invention, the pressure receiving chamber 61 of the speed regulator 60 and the intake control valve are placed on the secondary side of the pressure regulator 70 by the above-mentioned first flow path 81 and the second flow path 82 provided with the throttle 91. By adopting a configuration in which the valve closing pressure receiving chambers 51 of 50 are communicated in series, when the pressure in the supply flow path 3 (receiver tank 32) rises during normal operation and the pressure regulator 70 opens, the pressure regulator 70 passes through. The compressed gas is first introduced into the pressure receiving chamber 61 of the speed regulator 60 to increase the pressure in the pressure receiving chamber 61 of the speed regulator 60, and then introduced into the closed pressure receiving chamber 51 of the intake control valve 50. The pressure in the closed valve pressure receiving chamber 51 of the intake control valve 50 is increased.

As a result, when shifting from full-load operation to no-load operation, the speed regulator 60 first reduces the engine rotation speed, and then the intake control valve 50 closes the intake port 21 of the compressor body 2. , The fuel efficiency of the engine drive compressor 1 could be improved.

Bypassing the pressure regulator 70, one end 84a is communicated with the supply flow path 3 (receiver tank 32 in the embodiment), and the other end 84b is the pressure receiving chamber 61 of the speed regulator 60 and the intake control valve 50. Bypasses that are communicated in parallel with the pressure receiving chamber 61 of the speed regulator 60 and the valve closing pressure receiving chamber 51 of the intake control valve 50 via the flow paths (82, 85, 86) communicated with the valve closing pressure receiving chamber 51. In the capacity control device 5 provided with the start load reducing mechanism 4 including the flow path 84 and the on-off valve 41 for opening and closing the bypass flow path 84, the on-off valve 41 is operated to operate the bypass flow path when the engine drive compressor 1 is started. By opening 84, compressed gas can be introduced into the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50 at the same time, and the operation shifts from full load operation to no load operation during normal operation. When the engine speed is reduced, the engine speed can be reduced prior to the closing operation of the intake control valve 50. However, at the time of starting, the intake control valve 50 can be started at the same time as the engine speed is reduced or prior to the engine speed reduction. It was possible to perform the contradictory operations of causing the engine to perform the valve closing operation, and thereby the startability of the engine drive compressor 1 could be improved.

The other end 84b of the bypass flow path 84 is communicated with the second flow path 82 on the secondary side of the throttle 91, and the bypass flow path 84 is connected to the pressure receiving chamber 61 of the speed regulator 60 and the intake control. In the configuration in which the valve 50 communicates with the closed valve pressure receiving chamber 51 in parallel, not only the circuit configuration can be simplified by sharing the piping, but also the pressure receiving chamber 61 of the speed regulator 60 is connected to the pressure receiving chamber 61 of the speed regulator 60 via the throttle 91 at the time of starting. Since the compressed gas is introduced, the pressure increase in the pressure receiving chamber 61 of the speed regulator 60 can be delayed with respect to the pressure increase in the closed pressure receiving chamber 51 of the intake control valve 50.

As a result, at the time of starting, the intake control valve 50 closes the intake port 21 of the compressor main body 2 to reduce the load, and then the engine is shifted to a low speed, which further improves the startability of the engine-driven compressor 1. I was able to.

A branch flow path 83 is provided in which the second flow path 82 communicating the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50 is branched on the secondary side of the throttle 91, and the branch flow is provided. In the configuration in which the road 83 is opened to the atmosphere via the throttle 92, when the engine drive compressor 1 is stopped, the on-off valve 41 provided in the bypass flow path 84 is opened to drive the engine to the above-mentioned starting load reduction mechanism 4. It was possible to provide a function as a purge mechanism for releasing the compressed gas in the receiver tank 32 when the compressor 1 is stopped.

When the compressed gas filled in the receiver tank 32 is released in a short time and the inside of the receiver tank 32 is rapidly depressurized, the lubricating oil in the receiver tank 32 foams, so-called "forming" occurs. A branch flow path 83 is provided, two flow paths 85 and 86 branched from the other end 84b of the bypass flow path 84 are provided, and check valves 97 and 98 are provided in the respective flow paths 85 and 86 to branch. The other end 84b of the bypass flow path 84 communicates with the pressure receiving chamber 61 of the speed regulator 60 through one of the flow paths 85, and the bypass flow path 84 passes through the other branched flow path 86. In the configuration in which the other end 84b is communicated with the valve closing pressure receiving chamber 51 of the intake control valve 50, when the above-mentioned purging is performed using the starting load reducing mechanism 4, the compressed gas in the receiver tank 32 becomes a second flow. After passing through the throttle 91 provided in the road 82 and the throttle 92 provided in the branch flow path 83, the compressed gas in the receiver tank 32 is slowly released to the atmosphere, and the forming described above is performed. Was able to be prevented.

Explanatory drawing of the capacity control device of the engine drive compressor of this invention. Sectional view of the speed regulator. It is a cross-sectional view of an intake control valve, (A) is a cross-sectional view of an intake control valve in a state where the compressed gas is not introduced into the closed valve pressure receiving chamber 51, and (B) is a cross-sectional view of the compressed gas in the closed valve pressure receiving chamber 51. Sectional view of the intake control valve in the introduced state. A configuration obtained when the starting load reduction mechanism (FIG. 7) of Patent Document 1 is simply applied to the capacity control device (FIG. 1) of the engine drive compressor of the present invention, and problems newly occurring in the configuration. Explanatory drawing. (A) of the capacity control device of the engine drive compressor of the present invention provided with a starting load reduction mechanism shows the flow of compressed gas at the time of starting, (B) at the time of normal operation, and (C) at the time of stopping (purge). Explanatory drawing. The flow of compressed gas in the capacity control device of the engine drive compressor of the present invention provided with another starting load reducing mechanism (A) at the time of starting, (B) at the time of normal operation, and (C) at the time of stopping (purge). Explanatory drawing which showed. Explanatory drawing of the capacity control device of the conventional engine drive compressor equipped with a start load reduction mechanism.

The capacity control device for the engine-driven compressor of the present invention will be described below with reference to the accompanying drawings.

[Overall configuration of engine-driven compressor]
Reference numeral 1 in FIG. 1 is an engine-driven compressor provided with the capacitance control device 5 of the present invention, and the engine-driven compressor 1 is an engine for driving the compressor main body 2 and the compressor main body 2 (FIG. 1). (Not shown), the receiver tank 32 that introduces the compressed gas discharged from the compressor body 2 via the discharge pipe 31, the air work machine that does not show the compressed gas in the receiver tank, etc. are connected to the consumption side. The service pipe 33 for supplying is provided so that the compressed gas discharged by the compressor main body 2 can be introduced to the consumption side via the supply flow path 3 including the discharge pipe 31, the receiver tank 32, and the service pipe 33. It is configured.

In the embodiment shown in FIG. 1, an oil-cooled compressor body 2 that compresses the compressed gas together with the lubricating oil for lubrication, cooling, and sealing of the compression working space is adopted as the compressor body 2. Therefore, the above-mentioned receiver tank 32 is provided on the discharge side of the compressor main body 2 in order to separate the lubricating oil from the compressed gas discharged as a gas-liquid mixed fluid with the lubricating oil. , When an oil-free compressor body that does not need to inject lubricating oil into the compression action space for lubrication, cooling, and sealing is adopted as the compressor body 2, the receiver tank 32 is installed in the supply flow path 3. It may be configured not to be provided.

As described above, in the present embodiment in which the oil-cooled screw compressor is adopted as the compressor main body 2, the lubricating oil recovered in the receiver tank 32 is contained in the receiver tank 32, such as an oil cooler or oil (not shown). It is configured so that it can be supplied to the compressor main body 2 again via a filter.

[Capacity control device]
The capacity control device 5 of the present invention provided in the engine drive compressor 1 configured as described above includes a pressure-receiving closed valve type intake control valve 50 that controls the opening and closing of the intake port 21 of the compressor body 2 and an engine (FIG. A speed regulator 60 connected to a governor lever (not shown) (not shown) and a supply flow path 3 (in the illustrated example, the supply flow path 3) for supplying the compressed gas discharged by the compressor body to the consumption side are configured. A pressure regulator 70 communicated with the receiver tank 32) is provided.

In this capacity control device 5, when the pressure in the supply flow path 3 (receiver tank 32 in the illustrated example) rises above the operation start pressure of the pressure regulator 70, the speed regulator 60 starts decelerating the engine and takes in air. When the control valve 50 throttles the intake port 21 of the compressor main body 2, the pressure in the supply flow path 3 (receiver tank 32) rises above the no-load operation start pressure, and the pressure regulator 70 is fully opened, the speed regulator 60 is activated. It will be described with reference to FIG. 7 that the rotation speed of the engine is set to a low speed and the intake control valve 50 closes the intake port 21 of the compressor main body 2 to perform capacity control for shifting to no-load operation. It is common with the conventional capacity control device 105.

However, in the capacitance control device 105 described with reference to FIG. 7, the control flow path 181 communicating with the secondary side of the pressure regulator 170 is branched and parallel to the pressure receiving chamber of the speed regulator 160 and the pressure receiving chamber of the unloader regulator 152. In contrast to the capacity control device 5 of the present invention, the pressure receiving chamber 61 of the speed regulator 60 is provided on the secondary side of the pressure regulator 70 communicating with the supply flow path 3 (receiver tank 32). By communicating with the pressure receiving chamber 61 of the speed regulator 60 and communicating with the closed valve pressure receiving chamber 51 of the intake control valve 50 via the throttle 91, the pressure receiving chamber 61 of the speed regulator 60 is connected to the secondary side of the pressure regulator 70. The difference is that the closed valve pressure receiving chamber 51 of the intake control valve 50 is communicated in series.

The pressure regulator 70 described above opens and closes according to the pressure in the receiver tank 32 to start and stop the introduction of compressed gas to the secondary side, and the pressure in the receiver tank 32 is the operation start pressure of the pressure regulator 70. If it is less than, it is in a closed state and the introduction of compressed gas to the secondary side is stopped, while when the pressure in the receiver tank 32 becomes equal to or higher than the operation start pressure of the pressure regulator 70, the flow path provided inside begins to open. When the compressed gas in the receiver tank 32 exceeds a predetermined no-load operation start pressure, the pressure is fully opened, and the introduction of the compressed gas to the secondary side is controlled in this way.

The speed regulator 60 that communicates with the secondary side of the pressure regulator 70 is a diaphragm type air cylinder as shown in FIG. 2 in the present embodiment, and is attached to the diaphragm 67 that defines the pressure receiving chamber 61 of the speed regulator 60. When the governor lever of the engine (not shown) is connected to the tip of the shaft 62 and the compressed gas is not introduced into the pressure receiving chamber 61, the shaft 62 is retracted into the cylinder 63 by the return spring S. When the governor lever of the engine is moved to a high-speed position and the introduction of compressed gas into the pressure receiving chamber 61 is started, the shaft 62 is pushed out of the cylinder 63 as the pressure in the pressure receiving chamber 61 rises, and the engine Move the governor lever to a low speed position.

As shown in FIGS. 1 and 2, a plurality of communication holes 64 to 66 communicating with the pressure receiving chamber 61 described above are formed in the cylinder 63 of the speed regulator 60, and one of the communication holes 64 is pressed. A first flow path 81 is formed which communicates with the secondary side of the regulator 70 and communicates between the secondary side of the pressure regulator 70 and the pressure receiving chamber 61 of the speed regulator 60.

Of the communication holes 64 to 66 provided in the cylinder 63 of the speed regulator 60, in the communication hole 65 in which the throttle (orifice) 91 is built, the valve closing pressure receiving chamber 51 of the intake control valve 50 is provided in the communication hole 59 (59a). A second flow path 82 having a throttle 91 is formed so as to communicate between the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50. ..

In the configuration of the capacitance control device 5 shown in FIG. 1, the speed regulator 60 is not connected to the communication hole 66, and the communication hole 66 is closed with a lid or the communication hole 66 itself is not provided.

Further, the configuration of the intake control valve 50 shown in FIG. 3 shows a configuration in which two communication holes 59a (59) and 59b communicating with the closed valve pressure receiving chamber 51 are provided, but the capacity control shown in FIG. 1 is shown. In the configuration of the device 5, since the pipe is not connected to the communication hole 59b, the communication hole 59b is similarly closed with a lid, or the communication hole 59b itself is not provided.

The intake control valve 50 into which the compressed gas that has passed through the pressure receiving chamber 61 of the speed regulator 60 is introduced opens and closes the intake port 21 provided in the compressor main body 2 to control the intake amount of the compressor main body 2. In the present embodiment, the intake control valve 50 allows the passage of gas from the primary side to the secondary side when the valve is opened, but is a check valve that prevents the backflow of gas from the secondary side to the primary side. It is configured as a normally open valve with a function.

In order to impart the above-mentioned check function, in the present embodiment, the piston valve type intake control valve 50 shown in FIG. 3 is adopted, and among the intake flow paths 53 formed in the body 52, the valve The primary side of the seat 54 is opened to the atmosphere through an air filter (not shown), and the secondary side of the valve seat 54 is communicated with the intake port 21 of the compressor main body 2.

The valve body 55 of the intake control valve 50 has a mushroom shape provided with a valve shaft 55a and a disk-shaped flange 55b attached to one end of the valve shaft 55a, and the peripheral portion of the flange 55b of the valve body 55 is formed. The suction flow path 53 can be closed by being seated on the valve seat 54 provided in the suction flow path 53.

A cylinder 56 is provided in the body 52, and a bottomed hollow piston 57 is housed in the cylinder 56 together with a return spring S1. In the hollow space of the piston 57, the valve body 55 is described. Valve shaft 55a is inserted together with the return spring S2.

A valve closing pressure receiving chamber 51 is formed below the bottom of the piston 57, and when the compressed gas is not introduced into the valve closing pressure receiving chamber 51, the piston 57 returns as shown in FIG. 3 (A). The valve shaft 55a of the valve body 55 is pushed up by the return spring S2 housed in the hollow space of the piston 57 while being urged to the lower end position in the cylinder 56 by the spring S1, and the flange 55b is pushed up by the valve seat 54. The movement of the fluid from the secondary side to the primary side of the valve seat 54 in the suction flow path 53 is restricted, but the intake of the compressor body 20 regulates the movement of the fluid on the secondary side of the valve seat 54. When the pressure in the suction flow path 53 becomes negative, the flange 55b of the valve body 55 is configured to be separated from the valve seat 54 to allow the intake air to pass therethrough.

On the other hand, when the compressed gas is introduced into the valve closing pressure receiving chamber 51, the piston 57 rises in the cylinder 56, and the upper end of the piston 57 pushes up the back surface of the flange 55b of the valve body 55, as shown in FIG. 3 (B). As described above, the flange 55b of the valve body 55 is pressed against the valve seat 54 to close the suction flow path 53, so that the suction port 21 of the compressor main body 2 can be closed.

In the present embodiment, the intake control valve 50 has been described as having the above-mentioned structure with a check function, but the intake control valve 50 used in the capacitance control device 5 of the present invention has such a check function. Similar to the intake control valve 150 of the conventional capacitance control device described with reference to FIG. 7, the intake control valve of various known configurations such as the intake control valve 150 composed of a combination of the butterfly valve 151 and the unloader regulator 152 is not limited to the above. In the configuration shown in FIG. 7, the pressure receiving chamber of the unloader regulator 152 becomes the closed valve pressure receiving chamber 51 of the intake control valve described above.

The second flow path 82 that communicates between the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50 is branched on the secondary side of the throttle 91 to provide a branch flow path 83. A throttle 92 may be provided in the branch flow path 83 and may be opened to the atmosphere.

In the illustrated embodiment, the branch flow path 83 is communicated with the suction flow path 53 on the primary side of the valve seat 54 of the intake control valve 50 via the communication hole 59'in which the throttle 92 is built. The compressed gas released through the flow path 83 is released to the atmosphere through an air filter (not shown) provided on the primary side of the intake control valve 50 to reduce the air release noise.

In this way, in the configuration in which the branch flow path 83 branched from the second flow path 82 is open to the atmosphere, when the pressure in the receiver tank 32 drops below the operation start pressure of the pressure regulator 70 and the pressure regulator 70 closes, the speed is increased. The compressed gas introduced into the pressure receiving chamber 61 of the regulator 60 is released to the atmosphere, and the speed regulator 60 can be returned to the original position where the governor lever of the engine is in the high speed position.

On the other hand, the valve closing pressure receiving chamber 51 of the intake control valve 50 is provided with an air outlet 58 having a built-in throttle 93, and the compressed gas in the valve closing pressure receiving chamber 51 is throttled and released through the air vent 58. Then, the compressed gas introduced into the valve closing pressure receiving chamber 51 of the intake control valve 50 can be released, and when the introduction of the compressed gas from the receiver tank 32 is stopped, the pressure in the valve closing pressure receiving chamber 51 decreases. Therefore, the intake control valve 50 can be returned to the open position.

In this configuration, the check valve 96 may be provided in the second flow path 82 on the secondary side of the branch point with the branch flow path 83 described above.

In the engine drive compressor 1 provided with the capacity control device 5 of the present invention configured as described above, when the pressure in the receiver tank 32 rises and the pressure regulator 70 opens, the receiver tank passes through the pressure regulator 70. The compressed gas in 32 is introduced into the pressure receiving chamber 61 of the speed regulator 60 via the first flow path 81.

The compressed gas introduced into the pressure receiving chamber 61 of the speed regulator 60 is also introduced into the closed pressure receiving chamber 51 of the intake control valve 50 via the second flow path 82, but the throttle 91 is introduced into the second flow path 82. The pressure in the pressure receiving chamber 61 of the speed regulator 60 rises prior to the pressure rise in the closed valve pressure receiving chamber 51 of the intake control valve 50.

As a result, in the capacity control device 5 of the present invention, when shifting to the no-load operation due to the pressure increase in the receiver tank 32, the engine rotates prior to the blockage of the intake port 21 of the compressor main body 2 by the intake control valve 50. Since the speed is shifted to a low speed, the fuel efficiency of the engine-driven compressor 1 can be improved.

[Starting load example reduction mechanism]
FIG. 4 shows that the starting load reducing mechanism 104 provided in the conventional capacitance control device 105 described with reference to FIG. 7 is used as it is for the configuration of the capacitance control device 5 of the present invention described with reference to FIG. This is the configuration that is expected when

In this configuration, when the on-off valve 141 is operated to open the bypass flow path 184 when the engine drive compressor 1 is started, the compressed gas in the receiver tank 32 bypasses the pressure regulator 70 and the speed regulator 60 and the intake control valve 50. By introducing the engine drive compressor 1, the engine drive compressor 1 can be started in a state of no-load operation.

However, in the configuration of the capacitance control device 5 of the present invention, as described above, the pressure regulator operates the intake control valve 50 later than the operation of the speed regulator 60 when shifting to the no-load operation during the normal operation. The pressure receiving chamber 61 of the speed regulator 60 is communicated with the secondary side of the 70, and the closed pressure receiving chamber 51 of the intake control valve 50 is communicated in series with the pressure receiving chamber 61 of the speed regulator 60 via the throttle 91. Therefore, in the configuration of the starting load reducing mechanism 104 shown in FIG. 4, the engine first shifts to low-speed operation even at the time of starting, and then the intake control valve 50 closes the intake port 21 of the compressor main body 2. Therefore, an engine in an unstable operating state immediately after starting will reduce the rotation speed before the load is reduced due to the blockage of the intake port 21, so that the engine is likely to stall. Problems arise.

Therefore, in the capacity control device 5 of the present application, when shifting to the no-load operation during the normal operation, the rotation speed of the engine is first reduced, and the intake port 21 of the compressor main body 2 by the intake control valve 50 is delayed. At the time of starting, the engine speed is reduced and the intake port 21 of the compressor main body 2 is closed at the same time, or the intake air of the compressor main body 2 is taken in, while the engine is closed to perform no-load operation. The startability of the engine-driven compressor is improved by providing a starting load reducing mechanism 4 capable of reducing the rotation speed of the engine after closing the mouth 21 to reduce the load.

As a configuration of such a starting load reducing mechanism 4, the capacity control device 5 of the engine drive compressor 1 of the present invention bypasses the pressure regulator 70 and has one end 84a of the receiver tank 32 as shown in FIGS. 5 and 6. A bypass flow path 84 communicating with the bypass flow path 84 and an on-off valve 41 for opening and closing the bypass flow path 84 are provided, and the other end 84b of the bypass flow path 84 is closed with the pressure receiving chamber 61 of the speed regulator 60 and the intake control valve 60. The valve pressure receiving chamber 61 is communicated in parallel to form the starting load reducing mechanism 4.

In the embodiment shown in FIG. 5, the other end 84b of the bypass flow path 84 is communicated with the above-mentioned second flow path 82 on the secondary side of the throttle 91 to form a pressure receiving chamber 61 of the speed regulator 60 and an intake control valve 50. The other end 84b of the bypass flow path 84 is communicated in parallel with both of the valve closing pressure receiving chambers 51.

With this configuration, in the circuit configuration shown in FIG. 5, when the engine drive compressor 1 is started with the bypass flow path 84 opened by operating the on-off valve 41, as shown in FIG. 5 (A). In addition, the compressed gas in the receiver tank 32 can be introduced into the pressure receiving chamber 61 of the speed regulator 60 and the closed valve pressure receiving chamber 51 of the intake control valve 50 at the same time by bypassing the pressure regulator 70.

In the configuration shown in FIG. 5, the compressed gas is introduced into the pressure receiving chamber 61 of the speed regulator 60 via the bypass flow path 84 through the throttle 91 provided in the second flow path 82, and thus such a throttle. There is a delay in the pressure rise with respect to the valve closing pressure receiving chamber 51 of the intake control valve 50 in which the compressed gas is introduced without passing through the valve.

As a result, at the time of starting, the intake control valve 50 operates before the speed regulator 60, and after the intake control valve 50 closes the intake port 21 of the compressor main body 2 to reduce the load on the engine, the speed regulator 60 operates. By controlling the rotation speed of the engine to be reduced, the startability of the engine-driven compressor 1 can be improved.

In this way, the engine drive compressor 1 is started, the warm-up operation is performed for a predetermined time, and then the on-off valve 41 is operated to close the bypass flow path 84, so that the capacity is controlled by the pressure regulator 70. Move to operation.

In the illustrated example, the on-off valve 41 that opens and closes the bypass flow path 84 is configured by a solenoid valve, but the on-off valve 41 is not limited to the solenoid valve and is configured by an on-off valve that opens and closes manually. It may be something to do.

Further, in the configuration of the illustrated capacity control device 5 in which the branch flow path 83 provided by branching the second flow path is open to the atmosphere, the on-off valve 41 provided in the bypass flow path 84 is as shown in FIG. 5 (C). , This is opened not only at the time of starting but also when the engine drive compressor 1 is stopped, and the starting load reducing mechanism 4 is released from the compressed gas in the receiver tank 32 when the engine drive compressor 1 is stopped. It may be used as a mechanism.

In the capacitance control device 5 described with reference to FIG. 5, a configuration example in which the other end 84b of the bypass flow path 84 is communicated with the second flow path 82 on the secondary side of the throttle 91 has been described. Instead, in FIG. 6, the other end 84b of the bypass flow path 84 is branched in two directions via the manifold 95, and one of the branched flow paths 85 is connected to the pressure receiving chamber 61 of the speed regulator 60 via a check valve 97. The other branched flow path 86 is communicated with the closed valve pressure receiving chamber 51 of the intake control valve 50 via the check valve 98.

In the embodiment shown in FIG. 6, in addition to the communication hole 59a to which the second flow path 82 is connected, a communication hole 59b for communicating the other flow path 86 with the closed valve pressure receiving chamber 51 of the intake control valve 50 is provided. The other flow path 86 is communicated with the communication hole 59b. Instead of this configuration, for example, the other flow path 86 is communicated with the second flow path 82 on the secondary side of the check valve 96. As a result, the intake control valve 50 may be communicated with the closed valve pressure receiving chamber 51.

Also in the configuration of the starting load reducing mechanism 4 shown in FIG. 6, the pressure regulator 70 is bypassed and the speed regulator is started by starting the engine drive compressor 1 with the bypass flow path 84 opened by operating the on-off valve 41. The introduction of the compressed gas can be started at the same time in the pressure receiving chamber 61 of the 60 and the closed pressure receiving chamber 51 of the intake control valve 50.

As a result, when the engine drive compressor 1 is started, the timing at which the intake control valve 50 closes the intake port 21 of the compressor main body 2 can be made simultaneous with the timing at which the engine shifts to a low rotation speed, for example. The intake control valve 50 determines the timing at which the speed regulator 60 shifts the engine to low-speed operation by providing a throttle (not shown) in one of the flow paths 85 formed by branching the bypass flow path 84. It may be performed after closing the intake port 21 of 2.

As described above, in the capacity control device 5 provided with the starting load reducing mechanism 4 described with reference to FIG. 6, when the on-off valve 41 is opened when the engine drive compressor 1 is stopped, the compressed gas in the receiver tank 32 is purged. As shown by an arrow in FIG. 6C, the compressed gas in the receiver tank 32 has two throttles, a throttle 91 provided in the second flow path 82 and a throttle 92 provided in the branch flow path 83 (described above). As described above, when one of the flow paths 85 formed by branching the other end 84b of the bypass flow path 84 is provided with a throttle (not shown), the air is released through the three throttles). The compressed gas in the receiver tank 32 is released through only the throttle 92 provided in the branch flow path 83, which is slower than the configuration of the capacitance control device 5 described with reference to FIG. 5 (C). Be degassed.

Here, the sudden depressurization of the receiver tank 32 causes foaming of the lubricating oil stored in the receiver tank 32, which causes forming. The capacity of the engine drive compressor 1 described with reference to FIG. 6 In the configuration of the control device 5, as compared with the configuration of the capacitance control device 5 described with reference to FIG. 5 as described above, the decompression in the receiver tank 32 is performed more slowly, and as a result, more forming occurs. It has a difficult structure.

1 Engine drive compressor 2 Compressor body 21 Intake port (of compressor body)
3 Supply flow path 31 Discharge piping 32 Receiver tank 33 Service piping 4 Starting load reduction mechanism 41 On / off valve (solenoid valve)
5 Capacity control device 50 Intake control valve 51 Closed valve pressure receiving chamber 52 Body 53 Intake flow path 54 Valve seat 55 Valve body 55a Valve shaft 55b Flange 56 Cylinder 57 Piston 58 Air outlet 59, 59', 59a, 59b Communication hole 60 Speed Regulator 61 Pressure receiving chamber 62 Shaft 63 Cylinder 64, 65, 66 Communication hole 67 Diaphragm 70 Pressure regulator 81 1st flow path 82 2nd flow path 83 Branch flow path 84 Bypass flow path 84a One end (of bypass flow path)
84b The other end (of the bypass flow path)
85 One flow path 86 The other flow path 91-93 Squeezing 95 Manifold 96-98 Check valve 100 Engine drive compressor 104 Starting load reduction mechanism 105 Capacity control device 120 Compressor body 121 Intake port 130 Engine 132 Receiver tank 135 Governor lever 141 On-off valve 150 Intake control valve 151 Butterfly valve 152 Unloader regulator 160 Speed regulator 170 Pressure regulator 181 Control flow path 181a One flow path 181b The other flow path 184 Bypass flow path S, S1, S2 Return spring

Claims (5)

In an engine-driven compressor having an engine and a compressor body driven by the engine, and having a supply flow path for supplying the compressed gas discharged by the compressor body to the consumption side.
A pressure-receiving valve-type intake control valve that controls the opening and closing of the intake port of the compressor body, a speed regulator that reduces the rotation speed of the engine in response to a rise in pressure in the pressure receiving chamber, and a primary connected to the supply flow path. A pressure regulator is provided to open the valve when the pressure on the side exceeds the predetermined operation start pressure and introduce the compressed gas in the supply flow path to the secondary side.
The first flow path that communicates the secondary side of the pressure regulator with the pressure receiving chamber of the speed regulator and the pressure receiving chamber of the speed regulator communicate with the closed pressure receiving chamber of the intake control valve via a throttle. An engine-driven compressor, characterized in that a second flow path is provided and the pressure receiving chamber of the speed regulator and the closed valve pressure receiving chamber of the intake control valve are communicated in series on the secondary side of the pressure regulator. Capacity control device. Bypassing the pressure regulator, one end communicates with the supply flow path, and the other end communicates with the pressure receiving chamber of the speed regulator and the closed valve pressure receiving chamber of the intake control valve. A starting load reducing mechanism including a bypass flow path that communicates in parallel with the pressure receiving chamber of the speed regulator, the closed valve pressure receiving chamber of the intake control valve, and an on-off valve that opens and closes the bypass flow path is provided. The capacity control device for an engine-driven compressor according to claim 1. The other end of the bypass flow path is communicated with the second flow path on the secondary side of the throttle, and the other end of the bypass flow path is connected to the speed regulator via the second flow path. The capacity control device for an engine-driven compressor according to claim 2, wherein the pressure receiving chamber and the closed valve pressure receiving chamber of the intake control valve are communicated in parallel with each other. A branch flow path branched from the second flow path communicating the pressure receiving chamber of the speed regulator and the closed valve pressure receiving chamber of the intake control valve on the secondary side of the throttle is provided, and the throttle is provided in the branch flow path. The capacity control device for an engine drive compressor according to any one of claims 1 to 3, wherein the branch flow path is opened to the atmosphere. A branch flow path branched from the second flow path communicating the pressure receiving chamber of the speed regulator and the closed valve pressure receiving chamber of the intake control valve on the secondary side of the throttle is provided, and the throttle is provided in the branch flow path. At the same time, open the branch flow path to the atmosphere.
Two flow paths branched from the other end of the bypass flow path are provided, and the other end of the bypass flow path is communicated with and branched to the pressure receiving chamber of the speed regulator via one of the branched flow paths. The other end of the bypass flow path is communicated with the closed valve pressure receiving chamber of the intake control valve via the other flow path.
A check valve that allows the flow of compressed gas toward the pressure receiving chamber of the speed regulator is provided in one of the flow paths, and compression toward the closing pressure receiving chamber of the intake control valve is provided in the other flow path. The capacity control device for an engine-driven compressor according to claim 2, further comprising a check valve that allows the flow of gas.

Images