JPH0310369B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to compressed air pressure sources for use in pneumatic systems.

In a pneumatic system, if condensed water is contained in the compressed air discharged from the air compressor, rust will form inside each device in the system, leading to deterioration of the devices and causing problems such as reduced functionality. . In particular, if condensed water is contained in the compressed air in a vehicle's air brake system, this condensed water will freeze inside each device in cold weather, and as a result, each device will become inoperable and the vehicle will not be able to brake. There is a risk.

In order to avoid such risks, the compressed air pressure source of conventional pneumatic systems contains an air dryer device that houses a drying cylinder filled with a desiccant and has a compressed air inlet and a compressed air outlet, and a drive source. an air compressor driven and connected to the compressed air inlet; a desiccant regeneration tank connected to the compressed air outlet; and a compressor connected to the desiccant regeneration tank via a check valve. an air storage tank; a pressure governor that outputs an unload signal when the pressure in the compressed air storage tank reaches a specified upper limit pressure; and releases the unload signal when the pressure reaches the specified lower limit; an unloader control section that puts the air compressor into a no-load operating state in response to an unload signal supplied; and an unloader control section that communicates the inside of the drying cylinder with the atmosphere in response to an unload signal supplied from the pressure governor. It is equipped with a drain valve that opens and closes in response to release of the unload signal.
As a result, when the pressure inside the compressed air storage tank is below the specified lower limit pressure, the compressed air from the air compressor passes through the drying cylinder filled with desiccant, at which time water is removed and the desiccant is regenerated. The compressed air is supplied to the compressed air storage tank via the storage tank and check valve. Although dry compressed air is thus supplied to the compressed air storage tank, the desiccant itself becomes saturated with moisture over time. In order to remove this moisture, i.e. to regenerate the desiccant, furthermore in the above pneumatic system,
When the pressure in the compressed air storage tank exceeds the specified upper limit pressure, for example 8 kg/ ^cm2 , the pressure governor detects this and supplies an unload signal to the unloader control section of the air compressor and the control input port of the drain valve. Then, the air compressor is put into a no-load operation state and the drain valve is opened. When the drain valve is opened, the compressed air in the desiccant regeneration tank passes through the drying cylinder and closes the drain valve. is discharged from. At this time, the moisture in the desiccant is removed and regenerated. In other words, in a pneumatic system, it is generally required that the pressure in the storage tank be maintained within a specified range, but in the above pneumatic system, when this pressure exceeds the specified upper limit pressure, the air compressor is activated. The desiccant is regenerated in synchronization with the no-load operation state.

However, if a truck equipped with such a pneumatic system is left outdoors in the winter with the ignition key turned off when the drain valve is opened, the moisture adhering to the drain valve body may freeze, causing the drain to close. The valve may remain open and freeze. To prevent this, a heater is usually installed near the drain valve, but it only works when the engine is running, so it is necessary to turn on the heater when the ignition key is turned in to release the frozen state. During this period, if the pressure in the compressed air storage tank is below the specified lower limit pressure, the compressed air from the air compressor will leak from the drain valve and the pressure in the tank will not rise. This not only hinders the operation of external equipment connected to the tank, but also wastes energy.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a compressed air pressure source that always operates normally even in winter. According to the present invention, this object is achieved by an air dryer device containing a drying cylinder filled with a desiccant and having a compressed air inlet and a compressed air outlet; a desiccant regeneration tank connected to the compressed air outlet; a compressed air storage tank connected to the desiccant regeneration tank via a check valve; a pressure governor that outputs an unload signal when the pressure reaches a specified upper limit pressure, and releases the unload signal when the pressure reaches the specified lower limit; - An unload control unit that puts the compressor in a no-load operating state, and an unload control unit that opens a valve to communicate the interior of the drying cylinder with the atmosphere in response to an unload signal supplied from the pressure governor, and releases the unload signal. In the compressed air pressure source, the compressed air pressure source is equipped with a drain valve that closes when the drive source stops operating, and a detector that detects the stoppage of operation of the air compressor due to stoppage of the operation of the drive source and outputs a detection signal, and a detection signal from the detector. The unload signal supplied from the pressure governor to the drain valve is forcibly canceled in response to the signal, and the unload signal can be supplied from the pressure governor to the drain valve in response to the cancellation of the detection signal. This is accomplished by a compressed air pressure source provided with a switching device.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a compressed air pressure source showing one embodiment of the present invention, and shows the case where it is installed in a truck, for example. An inner hole 4 having an opening 3 at the top is formed, and an inlet 5 communicating with the inner hole 4 is provided on the upper side periphery of the main body 2 . At the bottom of the main body 2, a drain valve main body 7 of the drain valve 6 is integrally formed with the main body 2. On the other hand, a lid member 8 covering the inner hole 4 of the main body 2 is attached to the upper part of the main body 2 by fitting the fitting protrusion 9 into the opening 3. An outer seal ring 10 attached to the fitting protrusion 9 maintains airtightness between the inside of the inner hole 4 and the atmosphere. The lid member 8 and the main body 2 are integrally fixed to each other by a plurality of bolts 12 at their flange portions.

A boss portion 13 is formed in the center of the upper surface of the lid member 8, and the boss portion 13 has a pipe connection port 15 having a passage 14 therein communicating with the inside of the main body 2.
is provided. A valve seat 18 is formed in the passage 14, and a ball valve member 19 that can be seated on the valve seat 18 is arranged. This constitutes a check valve 20 that allows only a certain amount of air to flow.
Further, the passage 14 is provided with a throttle passage 21 that bypasses the check valve 20 and constantly communicates the inside of the main body 2 with the connection port 15. Piping connection port 15
The stop plate 11, which is press-fitted into the pilot hole of the pipe thread 61 formed in FIG.

The above-mentioned pipe connection port 15 is connected to the regeneration tank 17 via the pipe line 16, while the inlet port 5 is connected to the pipe line 22.
The outlet of the regeneration tank 17 is connected to the main tank 27 through a conduit 25 and a check valve 26. Governor 28 connected to main tank 27
For example, set the air pressure in the main tank 27 to 7 to 8 kg/
This governor is used to regulate the pressure within a range of cm ² .
Unloader 3 provided on compressor 23
0, and the pipe line 93 and the switching valve 9
0, drain valve 6 by line 94 and line 31
is connected to the control port 32 of. When the pressure in the main tank 27 reaches the specified upper limit pressure of 8 kg/cm ² , the governor 28 outputs an unload signal (air pressure signal) and supplies it to the unloader 30 and drain valve 8, so that the pressure in the main tank reaches the specified limit. When the lower limit pressure of 7Kg/cm ² is reached, the unload signal is released. When the unloader 30 is supplied with an unload signal from the governor 28, the air compressor 23
is in a no-load operating state.

One terminal of the solenoid of the electromagnetic switching valve 90 is connected to the positive electrode of a battery 91 via an ignition switch 92 that controls driving and stopping of the engine that is the driving source for the air compressor 23. The other terminal of the solenoid and the negative electrode of battery 91 are grounded. Therefore, when the ignition switch 92 is turned off, the solenoid is not energized and the electromagnetic switching valve 90 is in the state shown (in the upper position), and when the ignition switch 92 is turned on, the solenoid is energized and the electromagnetic switching valve 90 is in the state shown (in the upper position). 90 takes the lower position. That is, the solenoid acts as a detector that detects whether the engine, which is the drive source of the air compressor 23, is running or stopping.

A drying cylinder 34 that is inserted into the inner hole 4 from the opening 3 of the main body 2 and whose upper outer periphery fits into the recess 33 of the lid member 8.
A plurality of openings are formed at the bottom, a plurality of protrusions 35 are formed on the inner surface, and a positioning protrusion 36 is formed at the center of the outer surface of the bottom. The positioning protrusion 36 of the drying cylinder 34 is located in a hole 38 formed in the boss portion 37 of the drain valve body 7.
It is positioned relative to the main body 2 by being fitted into the main body 2. Inside the drying cylinder 34, a pair of upper and lower partition walls 39 and 40, an enlarged view of which is shown in FIG. Chamber 47 filled with 43
are divided.

The pair of partition walls 39 and 40 have the same configuration,
As clearly shown in FIG. 3, the lower partition wall 40 is arranged symmetrically in the upper and lower directions, but now the lower partition wall 40 will be explained with reference to FIG. 2.
1. It consists of a partition plate 42 having a large number of holes and a clamping band 43 for clamping these. The clamping band 43 is made of rubber, and has a pair of flange parts 44 and 45 that protrude in the inner diameter direction, and an outer flange part 46 that protrudes in the outer diameter direction on the same plane as the upper flange part 45. ing.
The filter cloth 41 is superimposed on the partition plate 42, and their peripheral edges are elastically clamped by a pair of inner flanges 44, 45 of a clamping band 43. The lower inner flange portion 44 is formed to be slightly thicker than the upper inner flange portion 45, and the tip of the upper inner flange portion 45 is slightly bulged downward. The peripheral edge of the partition plate 42 is received by the lower inner flange 44, and the peripheral edge of the filter cloth 41 superimposed on the partition plate 42 is pressed by the tip of the upper inner flange 45. As a result, the partition plate 42 and the filter cloth 41 are fixed to each other.

When the air dryer device 1 is assembled, the lower partition wall 40 configured as described above has a filter cloth 41.
At this time, the outer flange portion 46 of the clamping band 43 is bent upward along the inner surface of the drying tube 34, as shown in FIG. Partition wall 40 in condition
is slid downward and is received by a protrusion 35 at the bottom of the drying tube 34. Next, a predetermined amount of desiccant 48 is filled into the drying tube 34, and the upper partition wall 39 is inserted into the drying tube 34 with the filter cloth 41 facing downward as shown in FIG. In this case as well, the outer flange portion 46' of the clamping band 43' is attached to the drying tube 3.
Bend upward along the inner surface of 4.

The drying tube 34 filled with the desiccant 43 as described above is inserted into the main body 2, and the positioning protrusion 35 is fitted into the hole 38 of the boss portion 37, so that the drying cylinder 34 is positioned with respect to the main body 2. When the spring 49 is interposed between the upper partition wall 39 and the lid member 8, and the lid member 8 is fixed to the main body 2 with the bolts 12, the desiccant 48 in the chamber 47 of the drying tube 34 passes through the upper partition wall 39. and placed in a compressed state. In addition,
A seal ring 59 is interposed between the upper end of the drying cylinder 34 and the lid member 8.

The filter section 50 located below the drying tube 34 is incorporated into the main body 2 before the drying tube 34, and this filter section 50 will be explained next.

The filter section 50 consists of an annular upper holding member 52, a cone-shaped lower holding member 53, and an annular oil filter 54 held by these.
A filter portion 50 is disposed within the main body 2 so as to be aligned with the hole 38 of
A sealing member 51 whose details are shown in FIG. 4 is interposed between the drying tube 34 and the filter section 50.

The sealing member 51 is made of rubber and has a substantially annular shape, and includes a peripheral wall portion 55 and a pair of ring-shaped protrusions 56,5.
7 are integrally formed. Lower surface 5 of sealing member 51
8 has a shape that almost matches the outer surface shape of the upper peripheral edge 52a of the upper holding member 52 of the filter section 50, and when the sealing member 51 is set on the upper holding member 52, the peripheral edge 55 of the sealing member 51 is The sealing member 51 is engaged with the peripheral edge 52 a of the upper holding member 52 , thereby positioning the sealing member 51 with respect to the upper holding member 52 , that is, the filter portion 50 . Next, as described above, by inserting the drying cylinder 34 into the main body 2 and fixing the lid member 8 to the main body 2 with the bolts 12 via the spring 49, the drying cylinder filled with the desiccant 48 and the pressing force of the spring 49 are removed. The ring-shaped protrusions 56 and 57 of the sealing member 51 interposed between the drying tube 34 and the filter section 50 are crushed by the weight of the drying tube 34, thereby ensuring the sealing action of the main member 51. A passage 62 formed by the main body 2 and the drying cylinder 34 communicates with the inlet 5 on the one hand, and on the other hand, the passage 14 having the oil filter 54, the chamber 47, the check valve 20, and the throttle passage 21, and piping. Regeneration tank 17 via connection port 15 pipe line 16
communicate with.

On the other hand, the drain valve 6 has a hole 63 in the drain valve main body 7, and the hole 63 communicates with the control port 32 via a passage 64 and communicates with the inside of the main body 2 via a passage 65. The plug 60 inserted into the hole 63 has a hole 66 inside it.
and a hole 67 are formed, and a control piston 68 is slidably disposed within the hole 66. A discharge valve seat 69 is formed in the upper part of the hole 67, and the lower part of the hole 67 is open to the atmosphere.
A chamber 70 within the bore 63 defined by the plug 60 and the control piston 68 communicates with the control port 32 via a passage 64 . A valve member 71 made of an elastic material is fixed to the lower end of the control piston 68 with a bolt 73 via a stopper 72, and the valve member 71 cooperates with a discharge valve seat 69 to connect the inside of the main body 2 to the atmosphere. Control communication.
Hole 6 formed by control piston 68
A chamber 74 within 6 communicates with the passage 65 by a cutout passage 75 and a passage 76. A spring 77 tensioned within the chamber 74 always urges the control piston 68 upward. The plug 60 is prevented from coming off via a discharge pipe 78 by a retaining ring 79. 80,8
1 and 82 are seal rings.

Next, the operation of this embodiment will be explained.

In the illustrated state, the ignition switch 92 is turned off and the engine and air compressor 23 are inoperative, but if the ignition switch 92 is turned on now, the engine and air compressor will be activated. Then, the solenoid of the electromagnetic switching valve 90 is energized, the switching valve 90 takes the downward position, and the pipe line 93 and the pipe line 94 are connected. At this time, if the pressure inside the main tank 27 is below the specified lower limit pressure, for example 7 kg/cm ² , the governor 2
8 does not output an unload signal, the air compressor 23 is operated under load, and the drain valve 6 is in the illustrated state, that is, in the closed state.

When the air compressor 23 is operated under load, moist compressed air is sent out from the discharge port 24 through the pipe 2.
2 to the inlet 5. This compressed air is further supplied to the chamber 47 through the passage 62 and the oil filter 54, where it is dried by the desiccant 48 and becomes dry compressed air, which opens the check valve 20 and opens the passage 14 and the piping connection port 15. Through the regeneration tank 17
stored within. This dry compressed air is further stored in the main tank 27 from the outlet of the regeneration tank through a line 25 and a check valve 26. Main tank 2
The dry compressed air stored in 7 is supplied to various devices not shown in the figure, such as in an air brake system, as indicated by arrows.

When the air pressure in the main tank 27 reaches a predetermined value, for example 8 kg/cm ² , the governor 28 supplies an unloading signal to the unloader and the air compressor 2
3 is put into no-load operation, and this air pressure signal is supplied to the control port 32 of the drain valve 6. The signal pressure from the governor 28 supplied to the control port 32 is introduced into the chamber 70, and as this air pressure acts on the control piston 68, the control piston 68 compresses the spring 77 and moves downward in the figure. As the control piston 68 moves downward, the valve member 71
When the valve is removed from the discharge valve seat 69, the interior of the main body 2 is communicated with the atmosphere through the passage 65 and the passage 76. Then, the dry compressed air in the regeneration tank 17 passes through the pipe connection port 15 and the throttle passage 21 and enters the chamber 4.
The condensed water that is returned to the desiccant 7 and adhered to the surface of the desiccant 48 is discharged to the atmosphere through the filter 54, the passage 65, and the passage 76, and the desiccant 48 is regenerated.

When the compressed air in the main tank 27 is consumed by each device in the air brake system and the air pressure in the main tank 27 falls below the specified lower limit pressure of 7 kg/cm ² , the governor 28 sends an unload signal to the unloader 30. A signal is given to release the air compressor 23 and put the air compressor 23 into load operation again. That is, the signal pressure supplied to the drain valve 6 is released to the atmosphere, and the air pressure in the pipe line 31 is made zero. Then, the control piston 68 is pressed by the spring 77 and moves upward in the figure, and the valve member 71 is seated on the discharge valve seat 69, cutting off communication between the inside of the main body 2 and the atmosphere.
Thereafter, by repeating the above series of operations, dry compressed air whose pressure is regulated within a predetermined pressure range is constantly stored in the main tank 27.

Now, when the ignition switch 92 is turned off to stop the operation of the illustrated engine and the associated operation of the air compressor 23, the electromagnetic switching valve 9
0 assumes the upper position, that is, the position shown, and the conduit 94 is connected to the exhaust port EXH. As a result, the control port 32 of the drain valve 6 is communicated with the atmosphere, and if the drain valve 6 is in the open state at this time, the control piston 68 rises to the state shown in the figure. That is, at the same time as the ignition switch 92 is turned off, the unload signal supplied to the drain valve 6 is released.
The drain valve 6 is closed.

The embodiment of the present invention is constructed and operates as described above, and has the following effects.

That is, the upper and lower partition walls 39, 4 in the drying cylinder 34
0 consists of a filter cloth 41, a partition plate 42, and a clamping band 43, respectively.
Since they are fixed to each other simply by sandwiching their peripheral edges, the fixing work is extremely simple compared to the conventional method of applying adhesive. There is no risk of quality deterioration due to adhesive extrusion.

Also, as shown in FIG. 3, partition walls 39, 40
When inserting into the drying cylinder 34, the clamping band 43
The outer flange portions 46, 46' are bent upward and slid onto the inner wall surface of the drying tube 34, which is easier to insert into the drying tube 34 than with a conventional partition wall. That is, the partition walls 39 and 40 are connected to the drying cylinder 34.
Although it is not necessary to provide an airtight seal to the inner wall of the container, it is necessary to provide a slidable seal to prevent the desiccant 48 from leaking outside. For this reason, in the conventional partition wall, considerable precision was required in the value of the diameter, but in this embodiment, the clamping band 43
Since the outer flange portion 46 is bent, elastically comes into close contact with the inner wall of the drying cylinder 34, and is slidable against the inner wall, the diameter of the clamping band 43 does not require very high precision. Therefore, the processing of the partition wall of this embodiment is simpler than that of the conventional partition wall, and moreover, it is easier to set it in the drying cylinder.

Further, a sealing member must be interposed between the drying cylinder 34 and the filter section 50, but conventionally, a flat ring-shaped leather packing is used as the upper holding member 52.
Since it was only placed on the top surface, it sometimes moved when the drying cylinder was set on top of it, which made it difficult to accurately position the skin packing and assemble the device. In the example, simply engaging the sealing member 51 with the upper holding member 52 ensures accurate positioning at all times, which facilitates assembly of the device.

Furthermore, in this embodiment, when the ignition switch is turned off, the control of the drain valve 6 is also turned off.
Since the port 32 is communicated with the atmosphere and the drain valve 6 is forcibly closed, it is possible to leave the truck outdoors in the winter, unlike in the past.
This prevents the drain valve 6 from freezing in the open state, and the pneumatic system can always start operating stably when the ignition switch 92 is turned on.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the electromagnetic switching valve 90 is connected between the conduit 93 and the conduit 94, but it may be connected within the conduit 31 instead.

Furthermore, although the above embodiments have been described with reference to applications to trucks, the present invention is not limited thereto and can also be applied to general vehicles and other equipment using pneumatic pressure.

Furthermore, although the ignition switch 92 has been described as a means for stopping and starting the operation of the engine that is the drive source of the air compressor 23, the present invention is not limited to this, and various means can be considered depending on the applicable equipment.

Furthermore, in the above embodiment, the air compressor 23
The drain valve 6 is forcibly closed in response to stopping the operation of the engine, which is the driving source of the engine, that is, turning off the ignition switch 92. However, instead of stopping the operation of other equipment, such as an air compressor, the drain valve 6 is forcibly closed. The drain valve 6 may be forcibly closed in response to the stoppage of the operation of the drain valve 23.

Further, in the above embodiment, in order to close the drain valve 6, the unload signal is canceled and the pressure supplied to the drain valve 6 is set to atmospheric pressure, but the valve may be closed by an air pressure signal higher or lower than this. Depending on the drain valve, a pneumatic signal may be converted into an electrical signal and then provided.

As described above, the compressed air pressure source of the present invention is
a detector that detects the stoppage of operation of the air compressor due to stoppage of operation of the drive source and outputs a detection signal; and an unload that is supplied from the pressure governor to the drain valve in response to the detection signal from the detector. A switching device is provided that forcibly cancels the signal and switches so that an unload signal can be supplied from the pressure governor to the drain valve in response to the cancellation of the detection signal. The compressed air from the air compressor does not leak from the drain valve when starting operation.
It can always operate stably.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a compressed air pressure source showing an embodiment of the present invention, FIG. 2 is an enlarged side sectional view of a lower partition wall in the air dryer device shown in FIG. 1, and FIG. 3 is a block diagram of the air dryer shown in FIG. 1. FIG. 4 is an enlarged side sectional view of essential parts of a pair of partition walls incorporated in the device, and FIG. 4 is an enlarged side sectional view showing the sealing member in the air dryer device of FIG. 1 together with related parts. In the figure, 1... air dryer device,
2... Main body, 6... Drain valve, 17... Regeneration tank, 23... Air compressor, 26... Check valve, 27... Main tank, 28... Governor, 29
...Pipe line, 30...Unloader, 31...Pipe line,
32...Control port, 34...Drying tube,
48... Desiccant, 68... Control piston, 69... Discharge valve seat, 90... 2-position electromagnetic switching valve, 92... Ignition switch, 93,
94...Pipeline.

Claims (1)

[Claims] 1. An air dryer device containing a drying tube filled with a desiccant and having a compressed air inlet and a compressed air outlet, an air compressor driven by a drive source and connected to the compressed air inlet, and the compressor. A desiccant regeneration tank connected to the air outlet, a compressed air storage tank connected to the desiccant regeneration tank via a check valve, and a pressure inside the compressed air storage tank that reaches a specified upper limit pressure. a pressure governor that then outputs an unload signal and releases the unload signal when a specified lower limit pressure is reached;
an unload control section that puts the air compressor into a no-load operating state in response to an unload signal supplied from the pressure governor; The valve opens to communicate with the atmosphere,
In a compressed air pressure source equipped with a drain valve that closes in response to cancellation of an unload signal, a detector that detects a stoppage of operation of the air compressor due to a stoppage of operation of the drive source and outputs a detection signal;
In response to a detection signal from the detector, the unload signal supplied from the pressure governor to the drain valve is forcibly canceled, and in response to the cancellation of the detection signal, the unload signal is supplied from the pressure governor to the drain valve. A compressed air pressure source equipped with a switching device that can switch to supply a load signal.