JP4112057B2 - Air supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air supply device, for example, a technique effective when used in an air brake device of a large automobile such as a truck or a bus.
[0002]
[Prior art]
In general, air brake devices are widely used in large vehicles such as trucks and buses. Air brake devices used in large vehicles such as trucks and buses are displacement compressors (hereinafter referred to as compressors) driven by automobile engines, main air tanks, brake valves, brake actuators, pressure regulators, and check valves. When the pressure of the air stored in the main air tank by the compressor reaches the set value of the pressure regulator, the unloader is controlled to keep the compressor inlet open. The compressor load on the engine is reduced.
[0003]
Compressed air (hereinafter referred to as air) as a working fluid used in the air brake device contains water vapor sucked from the atmosphere. This water vapor condenses into water in the air circuit, and causes corrosion, malfunction and freezing in each part of the air circuit components. Therefore, in the air brake device, moisture in the air in the circuit is removed by providing a dehumidifier in the air circuit.
[0004]
As a conventional dehumidifier of this type, there is one configured to store a granular adsorbent (drying agent) in a housing and interpose it in an air circuit. If the adsorbent stored in the dehumidifier is in a state where it has absorbed moisture, the moisture adsorption capacity will decrease, so a regeneration process is required to dry the adsorbent by causing dry air to flow back to the absorbent that has absorbed moisture. become. Therefore, the dehumidifier is configured to open the exhaust port of the dehumidifier by the air signal pressure of the pressure regulator to cause the air in the regeneration air tank to flow backward into the adsorbent storage chamber and dry the adsorbent.
[0005]
[Problems to be solved by the invention]
However, in the conventional air brake device, since the unloader is incorporated in the compressor, the structure of the compressor becomes extremely complicated, the number of parts and the number of assembling steps increase, and there is a problem that maintenance becomes troublesome.
[0006]
An object of the present invention is to provide an air supply device that can omit the incorporation of an unloader into a compressor.
[0007]
[Means for Solving the Problems]
An air supply device according to the present invention includes a compressor for supplying air to an air tank to which an air actuator is connected, a dehumidifier interposed between the air tank and the compressor, and an internal pressure of the air tank as a set value. In the air supply device comprising a pressure regulator for controlling
A switching valve is interposed between the compressor and the dehumidifier ,
An oil separator having an exhaust port and a built-in oil filter is connected to this switching valve,
The switching valve is configured to switch the supply of air from the compressor to the dehumidifier to supply to the oil separator during unloading by the pressure regulator .
[0008]
According to the above-described means, the switching valve is switched from the dehumidifier side to the oil separator side by the pressure regulator when the air tank exceeds the set value, so that the discharge air of the compressor is released to the atmosphere via the oil separator. . Therefore, unloading can be performed without incorporating the unloader into the compressor.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view showing an air brake device according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing the switching operation.
[0010]
In the present embodiment, the air supply device according to the present invention is configured to be used for an air brake device mounted on a large automobile such as a truck or a bus. The air brake device includes a positive displacement air compressor (hereinafter referred to as a compressor) 1 driven by an automobile engine, a main air tank (hereinafter referred to as a main tank) 2 supplied with air by the compressor 1, and a brake valve 3. A brake actuator 4 serving as an air actuator connected to the main tank 2 via the pressure regulator 5, a pressure regulator 5 for controlling the internal pressure of the main tank 2 to a set value, a check valve 6, a dehumidifier 7, and a switching valve 8 are provided. .
[0011]
The dehumidifier 7 includes a substantially cylindrical main body 11 whose upper surface is open and whose lower surface is closed, and a lid 12 that is detachably attached to the upper surface opening of the main body 11. The lid 12 is bolted to the main body 11. The hollow housing 10 is configured by being fastened via the like (not shown). On the housing 10, a regenerative air tank 13 having a cylindrical shape with a closed top surface is detachably fitted to the lid body 12, and the regeneration air tank 13 is fastened to the main body 11 together with the lid body 12. . The housing 10 includes an inlet 14 connected to the discharge port of the compressor 1, a control port 15 connected to the pressure regulator 5, and an exhaust port 16 communicating with the atmosphere. Further, the cover 12 of the housing 10 includes an outlet 17 that communicates with the regeneration air tank 13 via a check valve 18 and a throttle port 19 that directly communicates with the regeneration air tank 13 with a slight passage. The regeneration air tank 13 includes an outlet 20 that communicates with the main tank 2 via the check valve 6.
[0012]
A dehumidifying cylinder 21 having an outer diameter smaller than the inner diameter of the main body 11 is concentrically fitted inside the housing 10, and the upper end portion of the dehumidifying cylinder 21 is fitted to the lid 12. An air passage 22 is formed between the outer periphery of the dehumidifying cylinder 21 and the inner periphery of the housing 10, and a wire mesh 23 is attached in the middle of the air passage 22. An oil filter 24 is concentrically arranged on the downstream side of the air passage 22. On the other hand, a bottom plate 25, a top plate 26, and a plurality of partition plates 27 are spaced apart from each other in the dehumidifying cylinder 21 and arranged horizontally, and the outer peripheral surface of each plate is detachably supported on the inner wall surface of the dehumidifying cylinder 21. ing. The bottom plate 25, the top plate 26, and the plurality of partition plates 27 are provided with a large number of vent holes over the entire surface, and a granular adsorbent 28 is provided between each partition plate 27, the bottom plate 25, and the top plate 26. Are stored.
[0013]
A regeneration control valve 30 is provided at a lower portion of the housing 10 with the valve box 31 fixed to the main body 11. This regeneration control valve 30 is configured as a normally closed pneumatic pilot operated switching valve, and is interposed between the regeneration port 32 communicating with the inside of the dehumidifying cylinder 21 in the adsorbent accommodating chamber and the exhaust port 16. The exhaust port 16 is opened by the air signal pressure to the control port 15. That is, the regeneration control valve 30 includes a valve port 33 established in the middle of the regeneration port 32 and the exhaust port 16 established in the valve box 31, and a valve seat formed around the valve port 33. 34, a valve body 35 that opens and closes the valve port 33, a piston 37 that is linked to a valve rod 36 that is connected to the valve body 35, and a piston 37 that is slidably fitted to the control port. 15 is provided with a valve chamber 38 connected to the upper pressure chamber 38a opposite to the valve body 35, and a valve spring 39 urging the piston 37 in the direction in which the valve body 35 is seated on the valve seat 34. Yes.
[0014]
The switching valve 8 is configured as a three-port two-position pneumatic offset direct pneumatic pilot operated switching valve, and is interposed between the discharge port of the compressor 1 and the inlet 14 of the dehumidifier 7. The switching valve 8 includes a main body 41 formed in a substantially cylindrical shape, and the main body 41 is attached to the inlet 14 of the dehumidifier 7. A discharge port of the compressor 1 is connected to a pump port 42 formed at one end of the main body 41, and an inlet 14 is connected to a load port 43 formed at the other end of the main body 41. A cylinder chamber 44 is formed at the end of the main body 41 on the pump port 42 side, and a piston 45 is fitted into the cylinder chamber 44 so as to be slidable in the axial direction of the main body 41. A control port 46 is opened at a position near the load port 43 with respect to the piston 45 in the main body 41 so as to communicate with the pressure chamber 44 a on the load port 43 side with respect to the piston 45 of the cylinder chamber 44. The output terminal of the pressure regulator 5 connected to the dehumidifier 7 is connected to 46.
[0015]
A communication chamber 47 is formed at the end of the main body 41 on the load port 43 side so as to communicate with the load port 43, and a valve hole 48 is formed between the communication chamber 47 of the main body 41 and the cylinder chamber 44. 47 and the cylinder chamber 44 are opened. A spool 49 is fitted into the valve hole 48 so as to be slidable in the axial direction. The end of the spool 49 on the pump port 42 side is connected to the end surface of the piston 45 on the side of the load port 43 so as to move together. The end of the spool 49 on the side of the load port 43 is inserted into the communication chamber 47. The piston 45 and the spool 49 are opened with a valve path 50 opened at the end face of the piston 45, and the pump port 42 side end of the valve path 50 is communicated with the pump port 42 via the cylinder chamber 44. The valve port 51 is opened at the end of the outer peripheral surface of the spool 49 on the side of the load port 43 so as to communicate with the valve passage 50. In this state, the valve passage 50 and the communication chamber 47 are communicated with each other.
[0016]
At a predetermined position on the inner peripheral surface of the valve hole 48, a drain port 52 connected to an oil separator 60, which will be described later, via a drain passage 53 is opened so as to face the outer peripheral surface of the spool 49. 52 is configured to be connected to a valve port 51 opened on the outer peripheral surface of the spool 49. A seal ring 54 is interposed between the drain port 52 and the cylinder chamber 44 in the valve hole 48 so as to seal the clearance between the inner peripheral surface of the valve hole 48 and the outer peripheral surface of the spool 49.
[0017]
The oil separator 60 includes a sealed container 61, and an inlet 62 and an exhaust outlet 63 are opened on the upper side wall of the container 61. A drain path 53 of the switching valve 8 is connected to the inlet 62, and the exhaust port 63 is open to the atmosphere. Inside the container 61, a wire mesh layer 64 and an oil filter 65 made of a fiber layer made of synthetic resin or the like are disposed in order from the top, and the wire mesh layer 64 communicates with the inlet 62. A communication path 66 is opened at the center of the metal mesh layer 64 and the oil filter 65 so as to penetrate in the vertical direction, and the upper end of the communication path 66 is connected to the exhaust port 63. An inclined surface portion 67 is formed at the bottom of the oil filter 65 of the container 61, and an oil reservoir 68 is formed at the lower end portion of the inclined surface portion 67. One end of an oil drain passage 69 is connected to the oil reservoir 68, and the other end of the oil drain passage 69 is connected to an oil pan 71 of the engine via a stop valve 70.
[0018]
Next, the operation will be described. First, a case where the internal pressure of the main tank 2 is less than a set value will be described. When the internal pressure of the main tank 2 is equal to or lower than the set value, the air signal pressure from the pressure regulator 5 is not applied to the control port 46 of the switching valve 8, and as shown in FIG. The valve port 51 is maintained in a state opened to the communication chamber 47. The air sent from the compressor 1 flows into the pump port 42 of the switching valve 8 of the dehumidifier 7, and the air that flows into the pump port 42 passes through the valve path 50, the valve port 51 and the communication chamber 47 and enters the inlet 14 of the dehumidifier 7. Flow into.
[0019]
The air flowing into the inlet 14 passes from the bottom side of the dehumidifying cylinder 21 into the dehumidifying cylinder 21 through the wire mesh 23 and the oil filter 24 of the air passage 22 formed between the housing body 11 and the dehumidifying cylinder 21. When the air passes through the air passage 22, the flow direction of the air is changed by the wire mesh 23 and gas-liquid separation is performed, so that the oil mist gradually increases. Oil mist rides on the air flow and is collected by the oil filter 24. The air from which the oil mist has been removed by the oil filter 24 passes through the vent holes of the bottom plate 25, the top plate 26 and the plurality of partition plates 27 and passes through the adsorbent 28 group and reaches the regeneration air tank 13 from the outlet 17. . At this time, since the air that has passed through the vent hole group effectively contacts the adsorbent 28 in the dehumidifying cylinder 21, the moisture of the air introduced into the dehumidifying cylinder 21 is adsorbed and captured by the adsorbent 28 and dehumidified. .
[0020]
Dry air in the regeneration air tank 13 is stored in the main tank 2 from the outlet 20 through the check valve 6. The air in the main tank 2 is sent to the brake actuator 4 at any time when the brake valve 3 is operated to execute the brake operation. Then, the air pressure in the main tank 2 gradually increases.
[0021]
Next, an operation when the internal pressure of the main tank 2 reaches a set value will be described. When the internal pressure of the main tank 2 becomes equal to or higher than the set value, the pressure regulator 5 is operated to apply the air signal pressure to the control port 46 of the switching valve 8 and the control port 15 of the dehumidifier 7. When an air signal pressure is applied to the control port 46 of the switching valve 8, the piston 45 moves to the pump port 42 side, and the valve port 51 of the spool 49 is connected to the drain port 52 as shown in FIG. . For this reason, the air sent from the compressor 1 to the pump port 42 flows into the inlet 62 of the oil separator 60 via the valve passage 50, the valve port 51, the drain port 52 and the drain passage 53. Therefore, the dehumidifier 7 is not supplied with air from the compressor 1.
[0022]
The air flowing into the container 61 from the inlet 62 of the oil separator 60 is discharged to the atmosphere from the exhaust port 63 of the container 61 through the wire mesh layer 64, the oil filter 65 and the communication path 66.
Thus, when the internal pressure of the main tank 2 becomes equal to or higher than the set value, the air discharged from the compressor 1 is released to the atmosphere without passing through the dehumidifier 7, so that the load applied to the compressor 1 is greatly reduced. It becomes a state. Therefore, the load on the engine for driving the compressor 1 is reduced.
[0023]
On the other hand, the air flowing into the container 61 of the oil separator 60 is gas-liquid separated because the flow direction is changed by the wire mesh layer 64 when passing through the container 61. The oil (mist) separated from the air (gas) and gas and liquid gradually enlarges and is collected by the oil filter 65 along the air flow. When the oil collected by the oil filter 65 is further enlarged, it is dropped onto the inclined surface portion 67 by its own weight and stored in the oil reservoir 68. The oil stored in the oil sump 68 is collected in the oil pan 71 by opening the stop valve 70 during regular or irregular maintenance inspection.
[0024]
That is, since the oil sent from the compressor 1 and released into the atmosphere is removed by the oil separator 60, the air released into the atmosphere is purified into clean air that does not contain oil. Therefore, even if the air discharged from the compressor 1 is released to the atmosphere, the atmosphere is not polluted. Moreover, since the oil used for lubricating the compressor 1 can be finally collected in the oil pan 71, oil loss can be prevented.
[0025]
On the other hand, the air signal pressure applied to the control port 15 of the dehumidifier 7 is guided to the valve chamber 38 to lower the piston 37, so that the valve port 33, that is, the exhaust port 16 is opened by the valve body 35 of the regeneration control valve 30. Is done. When the exhaust port 16 is opened, the inside of the dehumidifying cylinder 21 of the housing 10 communicates with the atmosphere, so that the air in the regeneration air tank 13 gradually flows into the dehumidifying cylinder 21 through the throttle port 19. The inflowing air flows back through each vent, adsorbent 28, oil filter 24, regeneration port 32, valve port 33, and exhaust port 16, and is released to the atmosphere. At this time, since the air effectively contacts the adsorbent 28 in the dehumidifying cylinder 21, the adsorbent 28 is effectively dried and regenerated. Air that is relatively moistened by drying the adsorbent 28 is discharged from the exhaust port 16 to the atmosphere.
[0026]
According to this embodiment, since it is not necessary to incorporate an unloader in the compressor, the structure and maintenance of the compressor can be greatly simplified, and the air piping between the compressor and the pressure regulator can be omitted. As a result, the number of parts of the air brake device can be reduced, and the manufacturing cost of the entire air brake and thus the entire automobile can be reduced.
[0027]
In addition, when the internal pressure of the main tank reaches the set value, the discharge air from the compressor can be released to the atmosphere via the oil separator without passing through the dehumidifier, so that unloading can be ensured.
In addition, when the discharge air of the compressor is released to the atmosphere, the oil in the discharge air can be recovered, so that contamination of the air can be prevented and oil loss can be prevented.
[0028]
Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.
[0030]
The air in the main tank is not limited to use in a brake actuator, but may be configured to be used in an air actuator such as an air cylinder, an air motor, or an air spring that assists a clutch, a transmission shift lever, or the like.
[0031]
In the above-described embodiment, the air brake device for large vehicles such as trucks and buses has been described. However, the present invention relates to clutch assist devices and air spring devices for large vehicles, and air brake systems and air spring systems for railway vehicles. It can be applied to all feeding devices.
[0032]
【The invention's effect】
As described above, according to the present invention, since it is not necessary to incorporate an unloader in the compressor, the structure and maintenance of the compressor can be greatly simplified, and the air piping between the compressor and the pressure regulator is omitted. As a result, the productivity of the entire air supply device can be greatly improved, and the manufacturing cost of the entire air supply device can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an air brake device according to an embodiment of the present invention.
FIG. 2 is a circuit diagram showing the switching operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Positive displacement air compressor, 2 ... Main air tank, 3 ... Brake valve, 4 ... Brake actuator, 5 ... Pressure regulator, 6 ... Check valve, 7 ... Dehumidifier, 8 ... Switching valve, 10 ... Housing, 11 ... Main body, 12 ... Lid, 13 ... Air tank for regeneration, 14 ... Inlet, 15 ... Control port, 16 ... Exhaust port, 17 ... Outlet, 18 ... Check valve, 19 ... Throttle port, 20 ... Outlet, 21 ... Dehumidification cylinder (Adsorbent storage chamber), 22 ... air passage, 23 ... wire mesh, 24 ... oil filter, 25 ... bottom plate, 26 ... top plate, 27 ... partition plate, 28 ... adsorbent, 30 ... control valve for regeneration, 31 ... valve Box, 32 ... Port for regeneration, 33 ... Valve port, 34 ... Valve seat, 35 ... Valve body, 36 ... Valve rod, 37 ... Piston, 38 ... Valve chamber, 38a ... Upper pressure chamber, 39 ... Valve spring, 41 ... Main body 42 ... Pump port 43 ... Load port 44 ... Linda chamber, 44a ... pressure chamber, 45 ... piston, 46 ... control port, 47 ... communication chamber, 48 ... valve hole, 49 ... spool, 50 ... valve path, 51 ... valve port, 52 ... drain port, 53 ... drain path 54 ... Seal ring, 60 ... Oil separator, 61 ... Container, 62 ... Inlet, 63 ... Exhaust port, 64 ... Wire mesh layer, 65 ... Oil filter, 66 ... Communication path, 67 ... Inclined surface portion, 68 ... Oil sump, 69 ... oil drain path, 70 ... stop valve, 71 ... oil pan.

Claims (3)

A compressor for supplying air to an air tank to which an air actuator is connected; a dehumidifier interposed between the air tank and the compressor; and a pressure regulator for controlling the internal pressure of the air tank to a set value. In the air supply device
A switching valve is interposed between the compressor and the dehumidifier ,
An oil separator having an exhaust port and a built-in oil filter is connected to this switching valve,
The switching valve is configured to switch the supply of air from the compressor to the dehumidifier to the supply to the oil separator during unloading by the pressure regulator. . The air supply device according to claim 1, wherein the switching valve is assembled to an inlet of the dehumidifier. The switching valve is configured to be switched from the dehumidifier to the oil separator by an air signal pressure for adsorbent regeneration to the dehumidifier of the pressure regulator. The air supply device described.

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