JPH10296038A - Compressed air supply system and air dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the technology to eliminate three pipes out of the five included in a conventional routine system and simplify the entire composition of the system significantly. SOLUTION: The compressed air supply system 100 is equipped with an air compressor 10 which discharges a compressed air, an air dryer 20 including a foreign matter removing means and an air tank 40 which stores the compressed air cleared of foreign matter by the air dryer 20. In this system 100, the drain valve 60 of the air dryer 20 is burdened with the unloading function of the air compressor 10 instead of incorporating the unloading mechanism in the air compressor 10. In addition, a check valve for preventing the compressed air contained in the air tank 40 from flowing back and a pressure governor for generating a pressure command to the drain valve 60 are incorporated or integrated into the air dryer 20. Thus it is possible to dispense with pipings (a third, a fourth and a fifth piping 33', 34', 35') around the pressure governor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle and the like, in which compressed air discharged from an air compressor is subjected to a process of removing foreign substances such as moisture by an air dryer, and then the processed compressed air is supplied to an air tank. The present invention relates to a compressed air supply system for storing in a predetermined pressure range, and more particularly to a technique effective for simplifying the configuration of the entire system.

[0002]

BACKGROUND OF THE INVENTION A compressed air supply system of this type basically includes an air compressor for discharging compressed air, an air dryer for removing foreign matter from the compressed air discharged from the air compressor, and an air dryer. And an air tank for storing the compressed air that has been subjected to the passage processing. Here, the removal of foreign matter by the air dryer generally includes, in addition to drying to remove moisture, other processing to remove foreign matter other than moisture, particularly oil. As means for removing foreign matter,
There are those that remove moisture and the like through a renewable desiccant, and those that condense and remove moisture and the like by cooling. In addition, the air dryer including foreign matter removing means
Usually, large water droplets and oil droplets are removed in advance by a filter or the like before the removal process using a desiccant. FIG. 1b is a schematic view of a conventional general compressed air supply system. As can be seen from this figure, the air compressor 1
0 'and the air dryer 20' are connected by a first pipe 31 ', and the air dryer 20' and the air tank 40 '
Are connected by a second pipe 32 ′. In order to keep the pressure inside the air tank 40 'within a predetermined range, a pressure governor 50' is connected to the air tank 40 'by a third pipe 33'.
The pressure command from 0 ′ (that is, the command pressure) is transmitted to the unloading mechanism in the air compressor 10 ′ by the fourth pipe 34 ′,
The fifth pipe 35 'communicates with the drain valve 60' of the air dryer 20 '. others,
The air tank 40 'is provided with a check valve 70' for preventing backflow of the compressed air. The above is described, for example, in FIG. 2 of JP-A-8-301100.
Has revealed. As described above, since the general system includes the first to fifth pipes 31 ′ to 35 ′,
The configuration of the system is complicated, and it is difficult to reduce the overall cost.

FIG. 1 of Japanese Patent Application Laid-Open No. 8-301100 shows an example in which the fourth piping 34 'is eliminated and the overall configuration of the system is slightly simplified. There, the air compressor 10 'is connected to the drain valve 60' of the air dryer 20 '.
Of the air compressor 10 ', and a pipe (a fourth pipe 34') from the pressure governor 50 'to the unload mechanism by providing an unload function for disabling the operation of the air compressor 10'. I'm trying to get rid of it.

[0004]

Here, further simplification of this kind of compressed air supply system is studied, and the air tank 4
Third pipe 3 from 0 'to pressure governor 50'
3 'and attention was paid to eliminating the fifth pipe 35' from the pressure governor 50 'to the drain valve 60'. That is, it has been found as a new problem to eliminate the third and fifth pipes 33 'and 35' in addition to the fourth pipe 34 '. Under this new problem, the inventor has noticed that the pressure governor 50 'and the check valve 70' are built in or integrated with the air dryer 20 '. However, it has been found that when the pressure governor 50 'and the check valve 70' are included in the air dryer 20 ', the opening of the exhaust passage of the pressure governor 50' may be blocked by icing or the like. This is because the air dryer 20 'is often mounted so as to be exposed to the outside of the vehicle body, and the amount of exhaust from the pressure governor 50' is small. If the exhaust port is blocked, the pressure governor 50 'cannot function normally,
The whole system including the air dryer 20 'will malfunction.

Accordingly, the present invention provides a technique capable of eliminating three of the five pipes included in the conventional general system, thereby greatly simplifying the entire configuration of the system. With the goal. Another object of the present invention is to provide a technique capable of effectively preventing the opening of the exhaust passage of the pressure governor from being blocked by icing or the like, even though the pressure governor and the check valve are included in the air dryer. The purpose of. Further, according to the present invention, it is possible to effectively prevent air including foreign matter discharged from the drain valve from intruding into the pressure governor although the exhaust passage from the pressure governor communicates with the exhaust passage of the drain valve. Yet another object is to provide technology.

[0006]

According to the present invention, an air dryer for removing foreign matter includes the following components A, B, C and D, that is, it is built in or integrated. A. Foreign matter removing means for removing foreign matter in compressed air to be treated B. B. A pressure governor that supplies and discharges a command pressure by opening and closing a valve in accordance with a change in the compressed air pressure in the air tank. D. A drain valve that opens in response to a command pressure from the pressure governor and discharges the foreign matter removed by the foreign matter removing means to the outside air as a drain, and performs an unload function of the air compressor. Check valve for preventing the compressed air stored in the air tank from flowing back to the foreign matter removing means side. Thus, the piping in the system is a first piping for connecting the air compressor and the air dryer, and an air dryer. And a second pipe for connecting the air tank and the air tank. Further, needless to say, since the drain valve performs the unloading function of the air compressor, it is not necessary to incorporate an unloading mechanism in the air compressor.

The pressure governor provided in the air dryer can be prevented from freezing by providing a heater at the opening of the exhaust passage. However, preferably, the exhaust passage from the pressure governor is
It is good to communicate with the exhaust passage of the drain valve. In this case, the exhaust air itself discharged from the drain valve in a large amount can prevent the opening of the exhaust passage of the pressure governor from freezing. In that case, in order to prevent exhaust air containing foreign matter from entering the pressure governor,
The junction of the exhaust passage from the pressure governor and the exhaust passage of the drain valve may be located closer to the opening of the exhaust passage of the drain valve than the seal of the drain valve. As a countermeasure for preventing the intrusion, an oil strap element having relatively low flow resistance such as crashed aluminum may be arranged in the exhaust passage or the opening of the pressure governor.

The present invention can be widely applied to a compressed air supply system and can be suitably applied to an air dryer, particularly an air dryer integrally including a regeneration purge tank. Among them, a drier containing a desiccant, including a base member having an inlet connected to an air compressor and an outlet connected to an air tank, and containing a desiccant at an upper portion or a side portion of the base member. It can be applied most effectively to an air dryer having a configuration in which a drain valve for regeneration is disposed below the base member. The base member of the air dryer having such a configuration is convenient for incorporating or integrating a pressure governor that generates a pressure command to the drain valve and a check valve that prevents backflow of compressed air from the air tank side.

The base member having the inlet and the outlet usually has a cylindrical portion extending downward and having an open lower end.
A drain valve is arranged at the back of the cylindrical portion. The inside of the cylindrical portion serves as an exhaust passage of the drain valve, and a silencer for reducing, for example, a drain discharge noise caused by the drain valve is disposed therein. As the silencer, a silencer having a tubular member forming a housing and a silencer element contained in the tubular member can be used.
Accordingly, by using the cylindrical member of the silencer as a partition wall, the confluence of the exhaust passage of the pressure governor and the exhaust passage of the drain valve is disposed at a position closer to the opening facing the outside than the seal portion of the drain valve. Exhaust air including the pressure can be prevented from entering the pressure governor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the overall configuration of a compressed air supply system according to the present invention will be described with reference to FIG. In the compressed air supply system 100 shown in FIG. 1A, similarly to the conventional one in FIG. 1B, an air compressor 10 driven by an engine of a vehicle to discharge compressed air and an air dryer including foreign matter removing means. 20 and an air tank 40 that stores compressed air that has been subjected to foreign matter removal processing by the air dryer 20. Therefore, the first piping 3 connecting the air compressor 10 and the air dryer 20
1, and the second pipe 32 connecting the air dryer 20 and the air tank 40 is necessary as in the conventional case. However, in this system 100, unlike the one shown in FIG. 1B, the air compressor 10 does not have a built-in unloading mechanism, but instead has the unloading function of the air compressor 10 on the drain valve 60 of the air dryer 20. I try to make it. Further, a check valve 70 for preventing the backflow of the compressed air in the air tank 40 and a pressure governor 50 for generating a pressure command for the drain valve 60 are both built in or integrated with the air dryer 20. As a result, pressure governor 5
0 pipes (third, fourth and fifth pipes 33 ′,
34 ', 35') are eliminated, and the piping configuration of the entire system is simplified.

Next, the air dryer 20 in which the features of the system 100 are summarized will be clarified with reference to FIGS. In addition, in each figure, a seal member is shown by the symbol s. As shown in the vertical sectional view of FIG. 2, the air dryer 20 has two pipe connection portions. One is an inlet 211 that communicates with the air compressor 10 through a first pipe 31, and the other is an air tank 4 through a second pipe 32.
Exit 213 that connects to zero. The compressed air entering from the inlet 211 is air before processing, and contains foreign matters such as moisture or oil. On the other hand, the compressed air after the processing exiting from the outlet 213 is the compressed air from which such foreign matter has been removed.
The compressed air after the treatment is used, for example, for operating an air brake device.

The inlet 211 and the outlet 213 are located on the side of the base member 210 which is a molded product of an aluminum-based metal. The base member 210 is a main component of the housing of the air dryer 20. The base member 210 serves as a mounting base for mounting the air dryer 20 itself to a fixed portion of the vehicle, and also serves as a support base for supporting the dryer 230 containing a renewable desiccant 238 therein. It becomes a housing for the drain valve 60 that discharges the drain containing the foreign matter to the outside air. The base member 210 has a cylindrical portion 212 extending downward. The diameter of the cylindrical portion 212 is smaller than that of the portion 214 having the inlet 211 and the outlet 213. The inside of the cylindrical portion 212 is a hole 215 having a substantially uniform inner diameter. The lower end of the hole 215 is open to the outside, and the upper end of the hole 215 is located at the center of the large-diameter portion 214 of the base member 210. The hole 216 is connected. Central hole 21
6 communicates with the entrance 211 and is also closed at the top by a lid plate 239. Lid plate 2
39 is similar to the outer cover 246 of the air dryer 20.
It is fixed to the upper surface of the base member 210 by mounting means 247 such as bolts and nuts. The lid plate 239 includes a concave portion 239a at the center, a small-diameter through hole 239b at the bottom of the concave portion 239a, and a large-diameter through hole 239c around the plate. The through hole 239b at the bottom of the concave portion 239a is
A hole for introducing compressed air to be processed into the central hole 216 from the inlet 211 to the dryer 230 side. And
The recess 239a following the through hole 239b is
This is a portion that, together with the casing 231, accommodates an oil mist filter 232 made of crashed aluminum or the like. The oil mist filter 232 in the concave portion 239a is a member for removing water and oil, not particularly minute oil mist, which have not been removed while passing through the central hole 216 from the inlet 211. The oil mist filter 232 removes the oil mist or the like in advance, thereby forming a renewable drying agent 238 inside the dryer 230.
Effectively prevent the deterioration of the function. The dryer 230 itself is the same as the conventional one, and in addition to the main drying agent 238,
A check valve 236 for defining a purge tank together with the outer cover 246 and the casing 231 and a throttle passage 237 for a regeneration cycle are included.
That is, the drier 230 effectively dries the compressed air passing through the desiccant 238 and removes the dried compressed air from the purge tank 2.
48, the air tank 40 is passed through the through hole 239c and the outlet 213 around the lid plate 239.
Supply to the side.

While the dryer 230 is located above the base member 210, the drain valve 60, which performs the function of discharging drain and the function of unloading the air compressor 10, is provided in the dryer 23.
It is inside the base member 210 located below the zero.
The drain valve 60 is located deep inside the cylinder 212, and a silencer 220 is disposed between the drain valve 60 and the opening of the cylinder 212 to reduce the drain sound of the drain valve 60. . Drain valve 60
Is provided with a valve body 62 that moves together with the control piston 61. The control piston 61 is normally urged upward by the force of a spring 63 to connect the valve body 62 to the plug 6.
It is in contact with the valve seat 646 on the fourth side. However, when a command pressure is applied to the control chamber 66 through the control passage 65 communicating with the pressure governor 50, the control piston 61 moves downward and separates the valve body 62 from the valve seat 646. As a result, the drain valve 60 is
6 is drained to the silencer 220 inside the cylinder 212 and the nipple 249 at the opening of the cylinder 212.
To the outside, that is, to the outside air. When the drain valve 60 is opened, the dry compressed air inside the purge tank 248 flows back through the throttle passage 237 inside the casing 231 of the dryer 230 to regenerate the desiccant 238. On the other hand, silencer 220
A cylindrical member 221 forming a housing;
1 and a silencer element 222 contained therein. The outer diameter of the cylindrical member 221 is suitable for the inner diameter of the cylindrical portion 212, but a part of the outer circumference is notched. The meaning of this notch will become apparent from the detailed description of the pressure governor 50 that appears later. The silencer element 222 itself is a mesh member such as crashed aluminum or a metal wire, and the same as the oil mist filter 232 can be used.
Note that the seal portion of the drain valve 60 (that is, the valve body 62)
And the valve seat 646) to prevent freezing.
The heater 68 is provided on the outer periphery of the cylindrical portion 212 near the seal portion (see FIG. 4).

The air dryer 20 according to an embodiment of the present invention not only integrates the pressure governor 50 into the air dryer 20 itself, but also inhibits the backflow of compressed air from the air tank 40 to the purge tank 248. , And a safety valve 80 that opens when the internal pressure of the air tank 40 becomes abnormally high and exhausts excess compressed air to the outside of the system. FIG. 2 shows a structure in which the check valve 70 and the safety valve 80 are integrated. Both valves 70 and 80 are located at a portion of base member 210 adjacent to outlet 213.
The base member 210 has a valve set hole 278 orthogonal to the outlet 213 extending in the horizontal direction. The check valve 70 and the safety valve 80 are set in the valve set hole 278 with their axes aligned. The check valve 70 is located at the back of the valve set hole 278 and includes a valve body 72 having a spherical shape, and a valve spring 73 for urging the valve body 72 toward a valve seat 2107 on the base member 210 side.
A cylindrical housing member 84 is screwed to the opening of the valve set hole 278 to support one end of the valve spring 73. The housing member 84 is a housing main body of the safety valve 80 and supports the rod 81 inside. The rod 81 supports a spring receiver 87 at one end on the inner side and a valve body 82 at the other end on the outer side. Valve 8
2 receives the urging force of the valve spring 83 on the outer periphery of the rod 81 and hits the valve seat 848 on the housing member 84 side, and the safety valve 80 is normally closed. Needless to say, the spring force of the valve spring 83 of the safety valve 80 is set to be larger than that of the valve spring 73 of the check valve 70. In the safety valve 80, when the acting force due to the pressure received at the upper end of the rod 81 exceeds the spring force of the valve spring 83, the rod 81 and the valve body 82 move downward in FIG. Thereby, the sealing of the seal portion by the valve seat 848 and the valve element 82 is released, that is, the valve is opened, and the abnormal pressure is released to the outside.

3 and a half cross-sectional view of FIG. 4 show a structure in which the pressure governor 50 is integrated with the base member 210 of the air dryer 20. In the base member 210, a governor set hole 250 orthogonal to the axis of the heater 68 is provided on the side of the drain valve 60 opposite to the side where the heater 68 for preventing freezing exists. The base member 210 itself defining the hole 250 constitutes a casing of the pressure governor 50. Therefore, components other than the casing of the pressure governor 50 are set inside the governor set hole 250. The governor set hole 250 is a hole that is closed at one end in the axial direction and is open at the other end, and has a gradually increasing diameter from the closed side to the open side. This is because each component of the pressure governor 50 can be easily set inside the governor set hole 250. The pressure governor 50 is substantially the same as the conventional one (for example, see Japanese Utility Model Registration No. 2504332) except for the way of taking the exhaust passage in addition to the casing. The piston 51 is located at the back of the hole 250, and the piston 51 partitions the inside of the governor set hole 250 into three chambers of a first chamber 251, a second chamber 252, and a third chamber 253. The first chamber 251 is located inside the hole 250 and communicates with the air tank 40 from the valve set hole 250 through the inlet passage 340. Also, the second
The chamber 252 is a chamber defined on the outer periphery of the piston 51 and communicates with the control chamber 66 on the drain valve 60 side through the control passage 65. The third chamber 253 is located on the opening side of the governor set hole 250 and communicates with the exhaust passage of the drain valve 60 through the exhaust passage 360.

The piston 51 has a valve member 52 urged toward a valve seat 514 on the piston 51 side by a spring 53 and a shaft member 5 urged toward a third chamber 253 by a spring 553.
5 is movably supported. The shaft member 55 has an internal passage 55t for exhaust, one end 55a facing the valve body 52, and the other end 55b abutting on the end of the pressure setting bolt 56. The pressure setting bolt 56, together with a nut 57 screwed thereto, can adjust the spring force of the pressure setting spring 58 to a predetermined set value. In the pressure governor, an exhaust port is usually provided at the opening of the hole 250. Here, the opening of the hole 250 is closed by the seal member 59.

In the pressure governor 50, the valve body 5
An air supply valve 540 is constituted by a peripheral portion of one surface of the valve body 2 and a valve seat 514 on the piston 51 side, and an exhaust valve 560 is constituted by a central portion of one surface of the valve body 52 and one end 55a of the shaft member 55. In the state shown in FIG. 3, the valve body 52 is seated on the valve seat 514 and closes the air supply valve 540, whereas it is separated from one end 55 a of the shaft member 55 and the exhaust valve 560 is opened. I have. The operation of the air compressor 10 causes the air tank 40
When the internal pressure rises and reaches the set pressure, the piston 51 overcomes the spring force of the pressure setting spring 58 and moves to the opening side. At this time, the valve element 52 follows the movement of the piston 51 under the force of the spring 53, and is in a state of sitting on one end 55a of the shaft member 55 (that is, a state in which the exhaust valve 560 is closed). Thereafter, when the piston 51 further moves to the opening side, the valve body 52 separates from the valve seat 514 of the piston 51,
The air supply valve 540 is opened and the control passage 65 is opened.
The command pressure is sent to the drain valve 60 through. As a result, the drain valve 60 opens, the air compressor 10 enters the unloading state, and the internal pressure of the air tank 40 does not increase and is kept at the upper limit. On the other hand, when the compressed air inside the air tank 40 is consumed and the internal pressure of the air tank 40 is reduced, the compressed air in the control chamber 66 moves in a direction opposite to the above-described operation, and the compressed air in the control chamber 66 is discharged from the control passage 66 through the exhaust valve 560. Through the third chamber 253 and the exhaust passage 360 to return to the load state shown in FIG.

Now, in the air dryer 20 or the system 100 including the same, the pressure governor 50 is connected to the governor set hole 2 in the base member 210 of the air dryer 20.
In addition, the inlet passage 340, the exhaust passage 360, and the control passage 65 for the pressure governor 50 are all provided inside the base member 210. Therefore, there is no external piping surrounding the pressure governor 50, and the piping system is greatly simplified. In addition, of these passages, the exhaust passage 36 which must be opened to the outside air
Since the opening of the pressure governor 50 is merged with the exhaust passage of the drain valve 60 in particular,
Can be effectively prevented from being frozen. Further, in order to prevent the drain discharged from the drain valve 60 from entering the pressure governor 50 through the opening of the exhaust passage 360 of the pressure governor 50, the drain is discharged to the outside air more than the seal portion of the drain valve 60. It may be provided at a position closer to the outlet (the opening of the exhaust passage on the drain valve 60 side, the opening of the nipple 249). As a particularly preferable means for that, there is a method of using a notched passage 362 on the outer periphery of the cylindrical member 221 of the silencer 220 as shown in FIG. According to this, the opening of the exhaust passage 360 opened on the inner wall of the cylindrical portion 212 of the base member 210 can be moved to the downstream side of the silencer 220 through the notch passage 362.

[Brief description of the drawings]

FIG. 1a is a piping diagram showing a system according to the present invention, and b is a piping diagram showing a conventional system.

FIG. 2 is a longitudinal sectional view showing one embodiment of an air dryer according to the present invention.

FIG. 3 is a partial cross-sectional view of the embodiment of FIG. 2;

FIG. 4 is a half sectional view of the embodiment of FIG. 2 from another direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Air compressor 20 Air dryer 31 1st piping 32 2nd piping 40 Air tank 50 Pressure governor 60 Drain valve 65 Control passage 70 Check valve 100 Compressed air supply system 210 Base member 211 Inlet 212 Tubular part 213 Outlet 220 Silencer 221 Tubular Member 230 Dryer 238 Desiccant 340 Inlet passage 360 Exhaust passage 362 Notch passage 540 Air supply valve 560 Exhaust valve

Claims (6)

[Claims] An air compressor for discharging compressed air, a compressed air discharged from the air compressor is received at an inlet side through a first pipe, and foreign matter contained in the compressed air is removed. A compressed air supply system comprising: an air dryer that is discharged from an outlet side; and an air tank that receives compressed air that has been subjected to foreign matter removal processing from the outlet side of the air dryer through a second pipe and stores the compressed air therein. A, B, C and D. A. Foreign matter removing means for removing foreign matter in compressed air to be treated B. B. A pressure governor that supplies and discharges a command pressure by opening and closing a valve in accordance with a change in the compressed air pressure in the air tank. D. A drain valve that opens in response to a command pressure from the pressure governor and discharges the foreign matter removed by the foreign matter removing means to the outside air as a drain, and performs an unload function of the air compressor. Check valve for preventing compressed air stored in the air tank from flowing back to the foreign matter removing means side 2. The compressed air supply system according to claim 1, wherein an exhaust passage from the pressure governor communicates with an exhaust passage of the drain valve. 3. A junction of an exhaust passage from the pressure governor and an exhaust passage of the drain valve is located closer to an opening of the exhaust passage of the drain valve than a seal portion of the drain valve. Compressed air supply system. 4. A base member having an inlet connected to the air compressor and an outlet connected to the air tank, and one end connected to the inlet and the other end connected to the outlet. A dryer containing a renewable desiccant therein, provided on the lower side of the base member than this dryer,
An air dryer having a valve that opens in response to a pressure command and a regeneration drain valve for regenerating the desiccant,
Inside the base member, a pressure governor that opens and closes a valve according to a change in compressed air pressure in the air tank to generate a pressure command for the drain valve, and a check valve that prevents backflow of dry compressed air stored in the air tank And an exhaust passage from the pressure governor communicates with an exhaust passage of the drain valve. 5. The base member includes a cylindrical portion extending downward and having a lower end opened, and a portion extending from the seal portion of the drain valve to an opening of the cylindrical portion at the back of the cylindrical portion. Is an exhaust passage of the drain valve, and on the inner wall of the cylindrical portion, at a position closer to the opening than the seal portion, an exhaust passage from the pressure governor and an exhaust passage of the drain valve are joined. The air dryer according to claim 4. 6. A silencer is provided inside the cylindrical portion for reducing a sound of discharging foreign matter by the drain valve,
The silencer includes a tubular member forming a housing, and a silencer element contained in the tubular member.
6. The cylindrical member functions as a partition wall for arranging a junction of an exhaust passage from the pressure governor and an exhaust passage of the drain valve closer to the opening than the seal portion. Air dryer.