JP4398837B2 - Air leak detection relief valve and internal combustion engine air starter system - Google Patents

Description

  The present invention relates to an air leak detection relief valve and an air starter system for an internal combustion engine including the same.

  Conventionally, an air starter system has been widely used as a starting device for an internal combustion engine. This air starter system includes an air starter, an air tank that stores compressed air compressed by a compressor, and a pilot-operated pressure reducing valve including a main valve and a pilot pressure reducing valve. The main valve of the pressure reducing valve is connected between them. The air starter is well known, and has a piston for projecting and retracting a pinion gear and a turbine for rotating the pinion gear, and an air pressure is applied to the piston to cause the pinion gear to protrude to connect the ring gear and the pinion gear of the internal combustion engine. The pinion gear is rotated through the turbine by meshing.

  When the internal combustion engine is started, the main valve is controlled via the pilot pressure reducing valve, the secondary pressure of the main valve is controlled to the operating pressure of the air starter, and the air starter is driven.

  On the other hand, during operation other than when the internal combustion engine is started or stopped, the main valve of the pressure reducing valve is closed so that compressed air is not supplied to the air starter.

  By the way, when leakage occurs in the main valve due to dust biting into the seat portion of the main valve of the pressure reducing valve or deterioration or damage of the seat portion, the pressure drop of the air tank or the pinion gear of the air starter during operation Damage to the pinion gear, etc. due to the jumping out of the gear. For this reason, management of the closing function of the main valve of the pressure reducing valve is indispensable for the maintenance of the air starter system.

  However, in the past, the leakage of the main valve of the pressure reducing valve of the air starter system and the management of the closing function have been performed by disassembling and testing the pressure reducing valve. The pinion gear can not be detected reliably and accidents such as a pinion gear jump-out accident cannot be reliably prevented, and a decrease in the closing function of the seat part of the pressure reducing valve cannot be detected at the initial minute air leakage stage. There was a problem that the compressed air was consumed wastefully.

  Accordingly, an object of the present invention is to reliably prevent a pinion gear jump-out accident or the like even if the pressure reducing valve closing function is lowered, and to prevent the pressure reducing valve seat function from being lowered initially. It is an object of the present invention to provide an air leak detection relief valve that can be detected at the stage of various air leaks.

  Another object of the present invention is to provide an internal combustion engine that can reliably prevent a pinion gear jump-out accident and the like and can detect a decrease in the closing function of the seat portion of the pressure reducing valve at the initial minute air leakage stage. It is to provide an air starter system for an engine.

In order to solve the above problem, the air leak detection relief valve of the present invention is
A valve body that is housed in a main body having an inlet and a discharge port so as to freely advance and retreat, and is pressed toward a closed position by control air supplied to the control port;
A spring for urging the valve body toward the open position;
And a detection tube that is movably fitted to the main body and moves by the air discharged from the discharge port and represents the degree of air leakage ,
The detection cylinder is rotated with respect to the main body by the air discharged from the discharge port .

  According to the air leak detection relief valve having the above-described configuration, for example, when the air starter is stopped, the valve body is positioned at the open position by the spring by not supplying the control air to the control port. . Therefore, even if the compressed air leaks from the pressure reducing valve or the like, the compressed air is discharged to the outside from the inlet of the air leak detection relief valve through the outlet. Accordingly, even if the closing function of the pressure reducing valve or the like is lowered, it is possible to prevent an accidental jumpout of the pinion gear of the air starter.

In addition, when compressed air is discharged from the inlet of the air leak detection relief valve to the discharge port, the detection cylinder is moved by the air discharged from the discharge port to indicate the degree of air leak. Accordingly, it is possible to easily and reliably detect a decrease in the function of closing the seat portion of the pressure reducing valve at the initial minute air leakage stage.
Further, if there is an air leak, the detection cylinder rotates, so that the air leak can be detected easily and reliably.

  In one embodiment of the air leak detection relief valve, the detection cylinder is lifted with respect to the main body by the air discharged from the discharge port.

  According to the embodiment, since the detection cylinder is lifted with respect to the main body by the air discharged from the discharge port, it is possible to easily detect an air leak due to a decrease in the closing function of the seat portion of the pressure reducing valve.

An air starter system for an internal combustion engine of the present invention is
A pneumatic drive air starter for rotating and rotating the pinion gear while rotating the pinion gear to rotate the ring gear of the internal combustion engine;
A pressure reducing valve;
The air leak detection relief valve having the inlet connected to the air pipe between the pressure reducing valve and the air starter,
When the air starter is driven, the air leak detection relief valve is positioned at the closed position by the control air supplied to the control port, and when the air starter is stopped, the control port is opened to detect the air leak. The relief valve is located in the open position.

  According to the air starter system of the internal combustion engine configured as described above, even if the closing function of the pressure reducing valve is lowered, the compressed air leaked by the air leak detection relief valve is discharged to the outside. Therefore, it is possible to prevent the pinion gear from popping out.

In addition, when compressed air leaks from the pressure reducing valve , the detection cylinder of the air leakage detection relief valve moves and rotates, so that the function of closing the seat portion of the pressure reducing valve is reduced at the initial minute air leakage stage. Can be detected.

  According to the present invention, it is possible to reliably prevent a pinion gear jump-out accident and the like, and to reliably and easily detect a decrease in the closing function of the seat portion of the pressure reducing valve at the initial minute air leakage stage. it can.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

First, the reference example shown in FIG. 1 will be described. As shown in FIG. 1, the air leak detection relief valve 10 of this reference example is provided with a plurality of outlets a around the cylindrical main body 1, an inlet b at the lower end, and a stepped valve seat 5 inside. Is provided. A valve body 2 is provided in the main body 1 so as to be able to advance and retreat, and the valve body 2 is brought into contact with and separated from the valve seat 5 so that the space between the inlet b and the plurality of outlets a can be closed or opened. It has become. The total area of the plurality of discharge ports a is larger than the area of the inlet b. The main body 1 and the valve body 2 are sealed with a seal member (O-ring) 13.

  The air leak detection relief valve 10 has a normally open structure in which the valve body 2 is biased by the spring 3 so as to be separated from the valve seat 5. A screw of a cap 6 having a control port 7 is screwed to the upper end of the main body 1. Compressed air is supplied to the control port 7 to bring the valve body 2 into close contact with the valve seat 5 so that the space between the inlet b and the plurality of outlets a can be closed.

  On the other hand, the detection cylinder 11 is fitted up and down and rotated freely around the outer peripheral portion of the main body 10 and around the discharge port a. As shown in FIGS. 2A and 2B, the detection cylinder 11 has a large-diameter inner peripheral portion 12 and a small-diameter inner peripheral portion 14. As shown in FIG. 1, the small-diameter inner peripheral portion 14 is disposed on the upper side and the large-diameter inner peripheral portion 12 is disposed on the lower side. It faces the outlet a.

  The detection cylinder 11 is made of a resin having a small specific gravity, for example, polytetrafluoroethylene (PTFE (for example, trade name: Teflon)).

  The main body 1 of the air leak detection relief valve 10 is screwed and fixed to the air pipe 40.

  When flowing compressed air for operating the equipment through the air pipe 40, the control air is led from the control line 41 to the control port 7 of the air leakage detection relief valve 10, and the valve body 2 is moved to the spring of the spring 3. The valve seat 5 is brought into close contact with the force to close the space between the inlet b and the outlet a.

  On the other hand, when compressed air for operating the device does not flow through the air pipe 40, the control line 41 is opened to the atmosphere, the control port 7 is opened to the atmosphere, and the valve body 2 is spring force of the spring 3. To separate from the valve seat 5 and open between the inlet b and the outlet a.

  In this state, if there is compressed air due to leakage in the air pipe 40, the compressed air is discharged from the inlet b of the air leak detection relief valve 10 to the outlet a. The compressed air from the discharge port a acts as a levitation force on the step d at the upper end of the large-diameter inner peripheral portion 12 of the detection cylinder 11 to lift the light detection cylinder 11 made of resin, It is discharged from between the lower end e and the outer surface of the air pipe 40.

  It is clearly understood that the compressed air leaks reliably and easily at the stage of the slight leak of compressed air by the rising of the detection cylinder 11. Further, the degree of leakage of the compressed air can be clearly understood from the lift amount of the detection cylinder 11.

  Since the total area of the plurality of outlets a of the air leak detection relief valve 10 is larger than the area of the inlet b, the air leak detection relief valve 10 functions reliably as a safety valve.

FIGS. 3A and 3B show a detection cylinder 21 of an air leak detection relief valve according to an embodiment of the present invention . In this air leak detection relief valve, the components other than the detection cylinder 21 are the same as those shown in FIG. 1, and FIG. 1 is used as necessary. The detection cylinder 21 is formed of a resin having a small specific gravity. The detection cylinder 21 is provided with small-diameter inner peripheral portions 23 and 24 on both sides of the central large-diameter inner peripheral portion 25. The inclined groove 26 is provided. Although not shown, the detection cylinder 21 is fitted to the main body 1 of FIG. 1 in the same manner as the detection cylinder 11 of FIG. 2, and the large-diameter inner peripheral portion 25 is opposed to the plurality of discharge ports a, and a plurality of inclinations. The small diameter inner peripheral portion 24 having the groove 26 is positioned on the lower side, and the small diameter inner peripheral portion 23 is positioned on the upper side.

  The detection cylinder 21 is rotated and lifted by an air flow discharged to the outside from the discharge port a through the plurality of inclined grooves 26. Thus, since the detection cylinder 21 rotates and lifts when there is a leak of compressed air, visual confirmation is easier.

  Furthermore, a pattern such as a spiral pattern may be provided on the outer surface of the detection cylinder 21 so that the rotation of the detection cylinder 21 can be easily understood.

FIG. 4 shows an air starter system of an internal combustion engine of a reference example .

  The compressed air stored in the air tank 29 is decompressed by the main valve 30 which is a so-called relay valve, and is supplied to the air starter 50 through the air pipe 40.

  The air starter 50 has a well-known structure (not shown), and has a piston for projecting and retracting the pinion gear 51 and a turbine for rotating the pinion gear 51. Then, compressed air is caused to act on the piston to cause the pinion gear 51 to protrude to mesh the ring gear 61 and the pinion gear 51 of the flywheel of the internal combustion engine, and then the pinion gear 51 is rotated via the turbine while being moved to the piston. If compressed air is not supplied, the piston is retracted by a spring, the pinion gear 51 is retracted to disengage the ring gear 61 and the pinion gear 51, and then the supply of compressed air to the turbine is stopped to stop the pinion gear 51. The rotation is stopped.

  The main valve 30 and the pilot pressure reducing valve 36 constitute a pilot operated pressure reducing valve. The control pressure (secondary pressure) subjected to pressure reduction control of the pilot pressure reducing valve 36 acts on one side of the piston 33 of the main valve 30 via the passage of the first switching position S1 of the switching valve 38 and the control line 41. On the other hand, the secondary pressure of the main valve 30 acts on the other side of the piston 33. Accordingly, the main valve 30 contacts and separates the valve body 32 from the valve seat 35 so that the pressure difference between the secondary pressure of the main valve 30 and the control pressure corresponds to the spring force of the spring 34. Thus, the secondary pressure is controlled to a desired pressure corresponding to the control pressure.

  On the other hand, the air leak detection relief valve 10 has the same structure as the air leak detection relief valve 10 of FIG. 1 and connects the inlet b to the air pipe 40.

  In the above configuration, when the switching valve 38 is positioned at the first switching position S1 in order to drive the air starter 50, the pilot pressure reducing valve 36 and the main valve 30 operate, and the control pressure of the pilot pressure reducing valve 36 is increased. Compressed air having a corresponding pressure is supplied from the main valve 30 to the air starter 50, and the ring gear 61 is rotationally driven via the pinion gear 51.

  At this time, the control air from the pilot pressure reducing valve 36 is guided to the control port 7 of the air leak detection relief valve 10 shown in FIG. 1 via the control line 41, and the valve body 2 resists the spring force of the spring 3. The valve seat 5 is brought into close contact with each other, and the space between the inlet b and the outlet a is closed.

  On the other hand, when the internal combustion engine is not operating or stopped, the switching valve 38 is positioned at the second switching position S2 to close the outlet side of the pilot pressure reducing valve 36 and the piston 33 of the main valve 31. Is opened to the atmosphere via the control line 41 and the passage of the second switching position S2 of the switching valve 38, the main valve 30 is closed, and the air starter 50 is not driven. At the same time, the control port 7 of the air leak detection relief valve 10 is opened to the atmosphere via the control line 41 and the passage of the second switching position S2 of the switching valve 38.

  Therefore, the valve element 2 of the air leak detection relief valve 10 is separated from the valve seat 5 by the spring force of the spring 3, and the space between the inlet b and the outlet a is opened.

  In this state, suppose that compressed air leaks to the main valve 30 due to dust biting between the valve body 32 and the valve seat 35 of the main valve 30 or deterioration or damage of the valve body 32 and the valve seat 35 over time. The leaked compressed air is discharged from the inlet b of the air leak detection relief valve 10 to the outlet a. The compressed air discharged from the discharge port a acts as a levitation force on the step portion d at the upper end of the large-diameter inner peripheral portion 12 of the detection cylinder 11 to lift the light detection cylinder 11 made of resin, thereby detecting the detection cylinder. 11 and the outer surface of the air pipe 40 are discharged. Therefore, even if compressed air leaks, the drive of the air starter 30 is prevented, and damage to the pinion gear 51 and the like due to the pinion gear 51 jumping out is prevented.

Further, it can be clearly seen that the compressed air leaks reliably and easily at the stage of a slight leak of compressed air due to the floating of the detection cylinder 11 caused by the leak of compressed air. Further, the degree of leakage of the compressed air can be clearly understood from the lift amount of the detection cylinder 11. Therefore, maintenance work can be performed quickly and appropriately.
When the air leak detection relief valve 10 of the air starter system of the internal combustion engine of this reference example is replaced with the air leak detection relief valve having the detection cylinder 21 of FIG. 3, the air starter system of the internal combustion engine of the embodiment of the present invention is configured. it can.

  In the above-described embodiment, the pilot operated pressure reducing valve including the main valve 30 and the pilot pressure reducing valve 36 is used as the pressure reducing valve. However, a direct acting pressure reducing valve may be used.

FIG. 1 is a sectional view of an air leak detection relief valve of a reference example . 2A and 2B are a cross-sectional view and a side view of a detection cylinder of a reference example . 3A and 3B are a cross-sectional view and a side view of a modified example of the detection cylinder. FIG. 4 is a schematic diagram of an air starter system of a reference example .

DESCRIPTION OF SYMBOLS 1 Main body 2 Valve body 3 Spring 4 Valve seat 7 Control port 10 Air leak detection relief valve 11, 21 Detection cylinder 26 Inclined groove 30 Main valve 36 Pilot pressure reducing valve 38 Switching valve 50 Air starter 51 Pinion gear 61 Ring gear a Exhaust port b Inlet

Claims (3)

A valve body that is housed in a main body having an inlet and a discharge port so as to freely advance and retreat, and is pressed toward a closed position by control air supplied to the control port;
A spring for urging the valve body toward the open position;
And a detection tube that is movably fitted to the main body and moves by the air discharged from the discharge port and represents the degree of air leakage ,
The air leak detection relief valve , wherein the detection cylinder is rotated with respect to the main body by air discharged from the discharge port .   The air leak detection relief valve according to claim 1, wherein the detection cylinder is lifted with respect to the main body by the air discharged from the discharge port. A pneumatic drive air starter for rotating and rotating the pinion gear while rotating the pinion gear to rotate the ring gear of the internal combustion engine;
A pressure reducing valve;
The air leak detection relief valve according to claim 1 or 2 , wherein the inlet is connected to an air pipe between the pressure reducing valve and an air starter.
When the air starter is driven, the air leak detection relief valve is positioned at the closed position by the control air supplied to the control port, and when the air starter is stopped, the control port is opened to detect the air leak. An air starter system for an internal combustion engine, wherein the relief valve is located at an open position.

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