JP7269004B2 - air supply system - Google Patents

Description

The present invention relates to an air supply system for supplying compressed air to equipment.

2. Description of the Related Art In vehicles such as trucks, buses, and construction machines, pneumatic systems such as brakes and suspensions are controlled using compressed air sent from compressors. This compressed air contains liquid impurities such as moisture contained in the atmosphere and oil that lubricates the inside of the compressor. When compressed air containing a large amount of water and oil enters the pneumatic system, it causes rust and swelling of rubber members, resulting in malfunction. For this reason, an air dryer is provided downstream of the compressor for removing impurities such as moisture and oil from the compressed air.

The air dryer performs a dehumidifying operation for removing oil and moisture, and a regeneration operation for removing oil and moisture adsorbed by the desiccant and discharging the oil and moisture as drain. For example, Patent Literature 1 describes an example of a technique for an air dryer to perform a regeneration operation.

The air supply system described in Patent Literature 1 stores air compressed by a compressor in an air tank. When the air pressure in the air tank is below the first pressure, the compressor is driven to supply compressed air to the air tank until the air pressure rises to reach the second pressure. When the air pressure reaches the second pressure, the supply of compressed air from the compressor to the air tank is stopped and the purge valve is opened. Thereafter, by maintaining this valve open state until the air pressure drops to the third pressure, a regeneration operation is performed in which the compressed air in the air tank is passed through the air dryer and discharged to the atmosphere. Then, when the air pressure in the air tank reaches the third pressure, the discharge valve is closed.

JP 2015-229127 A

By the way, when the vehicle runs downhill or when the vehicle is decelerated or stopped due to traffic jam, the compressed air in the air tank is consumed by driving the brakes. Compressed air is consumed by driving the brake, etc., during the supply operation of the air dryer that supplies the compressed air from the compressor to the air tank, and during the regeneration operation that consumes the compressed air from the air tank. As a result, for example, in the technology described in Patent Document 1, in the supply operation, the compressed air including the amount consumed in driving the brake is supplied in the supply operation, and in the regeneration operation after the supply operation, Air dryer desiccant may not fully regenerate dehumidification performance. In addition, as in the technique described in Patent Document 1, if the air pressure determines whether or not the regeneration operation is performed, a large amount of compressed air is consumed by the brake or the like at the same time as the regeneration operation, until the regeneration operation ends. Air pressure drops in a short time. In other words, an excessive supply of compressed air increases the amount of dehumidification required of the air dryer, and a large amount of compressed air consumed during the regeneration operation results in insufficient regeneration of the air dryer, thereby deteriorating the performance of the air dryer. There is a risk.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air supply system capable of suppressing performance deterioration of an air dryer.

An air supply system that achieves the above object is an air supply system that performs a supply operation to flow compressed air from a compressor through an air dryer having a desiccant and a check valve, from upstream to downstream, the supply operation and a non-return valve. a control device that switches between the supply operation and the non-supply operation and includes a regeneration operation for regenerating the desiccant in the non-supply operation, wherein the control device controls the supply operation from before the start of the previous regeneration operation to before the start of the current regeneration operation. If the amount of compressed air in operation is greater or less than that suitable for regeneration in a predetermined period, the regeneration period, which is the length of time during which the regeneration operation is performed, is adjusted.

With such a configuration, the length of the regeneration period is adjusted for a predetermined period based on the amount of compressed air in the supply operation. As a result, deterioration in the performance of the air dryer in the air supply system can be suppressed.

As a preferred configuration, the control device can acquire the rotation speed of the compressor, and acquires the ventilation amount based on the rotation speed of the compressor.
According to such a configuration, the length of the regeneration period is adjusted based on the ventilation amount of the compressed air.

As a preferred configuration, the control device adjusts the regeneration period to be longer than the predetermined period in response to the fact that the ventilation amount is greater than the reference ventilation amount used as a reference, thereby achieving the reference ventilation amount. The regeneration period is adjusted to be shorter than the predetermined period according to the fact that the ventilation amount is smaller than the predetermined period.

According to such a configuration, it is possible to adjust the length of the predetermined period based on the comparison between the ventilation amount and the reference ventilation amount.
An air supply system that achieves the above object is an air supply system that performs a supply operation to flow compressed air from a compressor through an air dryer having a desiccant and a check valve, from upstream to downstream, the supply operation and a non-return valve. a control device for switching between the supply operation and the non-supply operation and including a regeneration operation for regenerating the desiccant in the non-supply operation, wherein the control device controls the amount of the compressed air after the supply operation is started. It is reset according to the start of the regeneration operation, and the difference between the ventilation amount before the reset and the ventilation amount suitable for regeneration in a predetermined period in which the regeneration operation is performed is used as the ventilation amount after the reset. to add.

According to such a configuration, the amount of ventilation that is insufficiently regenerated during the regeneration period is added to the next amount of ventilation, so that insufficient regeneration is not cumulatively accumulated. Therefore, deterioration of the performance of the air dryer can be suppressed.

ADVANTAGE OF THE INVENTION According to this invention, the performance fall of an air dryer can be suppressed.

1 is a block diagram showing a schematic configuration of an embodiment of an air supply system used in a pneumatic system; FIG. The block diagram which shows the schematic structure of the air supply system in the same embodiment. FIG. 4 is a diagram showing operation modes of the air dryer in the same embodiment, where (a) is a diagram showing a supply operation, (b) is a diagram showing a purge operation, and (c) is a diagram showing a regeneration operation. 4 is a graph showing the relationship between the amount of ventilation and the extended time of regeneration operation in the same embodiment. 5 is a graph showing the excess amount of air ventilation at the start of regeneration operation in the same embodiment. 4 is a graph showing excess air pressure at the start of regeneration operation in the same embodiment.

One embodiment of an air supply system included in a pneumatic system will be described with reference to FIGS. 1 to 6. FIG. Air supply systems are installed in automobiles such as trucks, buses, and construction machines.

An overview of the pneumatic system will be described with reference to FIG.
In the pneumatic system, a compressor 4, an air dryer 11, a protection valve 12, an air tank 13, a brake valve 14, and a brake chamber 15 are sequentially connected via air supply paths 4E, 11E, 12E, 13E, 14E. Among them, the compressor 4 , the air dryer 11 and the protection valve 12 constitute an air supply system 10 .

The compressor 4 is driven by the power of an automobile engine (not shown), compresses air, and supplies it to the air supply system 10 . An air dryer 11 is provided in an air supply path 4E connected to the compressor 4. As shown in FIG.

In the air dryer 11, the compressed air sent from the compressor 4 passes through the desiccant 17 (see FIG. 2) to capture impurities and purify the compressed air. The compressed air cleaned in this way is supplied from the air dryer 11 to the air tank 13 via the air supply path 11E, the protection valve 12 and the air supply path 12E.

The air tank 13 is connected via an air supply path 13E to a brake valve 14 operated by the driver. The brake valve 14 is connected to the brake chamber 15 via an air supply passage 14E. Therefore, according to the operation of the brake valve 14, compressed air is supplied to the brake chamber 15 to operate the service brake.

The air supply system 10 also includes an ECU 80 as a control device. The ECU 80 is electrically connected to the air dryer 11 via wires E62 and E63. Further, the ECU 80 is electrically connected to the pressure sensor 65 via the wiring E65. A pressure sensor 65 detects the air pressure in the protection valve 12 and outputs it to the ECU 80 . The ECU 80 acquires the detected air pressure corresponding to the air pressure in the air tank 13 from the detection signal of the pressure sensor 65 . The ECU 80 is also electrically connected to the temperature/humidity sensor 66 via the wiring E66. The temperature/humidity sensor 66 detects the humidity of the compressed air in the air tank 13 and outputs it to the ECU 80 . Also, the temperature/humidity sensor 66 may be arranged immediately downstream of the air dryer 11 to detect the humidity of the compressed air in the air tank 13 . Further, the ECU 80 is electrically connected to the vehicle ECU 100 so as to be able to acquire various signals of the vehicle in which the air supply system 10 is installed. For example, the signals that can be obtained include the number of revolutions of the compressor.

The ECU 80 includes an arithmetic unit, a volatile storage unit, and a nonvolatile storage unit, and provides signals and the like for instructing various operations to the air dryer 11 according to programs stored in the nonvolatile storage unit.

The air supply system 10 will be described with reference to FIG.
The air dryer 11 has a maintenance port P12. The maintenance port P12 is a port for supplying compressed air upstream of the desiccant 17 of the air dryer 11 during maintenance.

The ECU 80 is electrically connected to the regeneration control valve 21 of the air dryer 11 via wiring E63, and is electrically connected to the governor 26 of the air dryer 11 via wiring E62.
The air dryer 11 has a desiccant 17 inside 11A (see FIG. 3). The desiccant 17 is provided in the middle of the air supply passage 18 connecting the air supply passage 4E from the compressor 4 on the upstream side and the air supply passage 11E leading to the protection valve 12 on the downstream side.

The desiccant 17 is silica gel, zeolite, or the like, and dries the compressed air by removing moisture contained in the compressed air by allowing the compressed air to pass through, and also removes oil contained in the compressed air to purify the air. Compressed air that has passed through the desiccant 17 is supplied to the protection valve 12 via a check valve 19 as a check valve that allows air to flow only downstream from the desiccant 17 . In other words, the check valve 19 allows air to flow only from upstream to downstream when the desiccant 17 is upstream and the protection valve 12 is downstream.

The check valve 19 is provided with a bypass flow path 20 that bypasses the check valve 19 in parallel with the check valve 19 . A regeneration control valve 21 is connected to the bypass flow path 20 .

The regeneration control valve 21 is an electromagnetic valve whose operation is switched by turning on/off (driving/non-driving) the power from the ECU 80 via the wiring E63. The regeneration control valve 21 is closed to seal the bypass channel 20 when the power is off, and is opened to communicate the bypass channel 20 when the power is on. For example, the regeneration control valve 21 is driven when the detected air pressure value exceeds the supply stop value.

The bypass flow path 20 is provided with an orifice 22 between the regeneration control valve 21 and the desiccant 17 . When the regeneration control valve 21 is energized, the compressed air in the air tank 13 is sent through the protection valve 12 to the desiccant 17 through the bypass flow path 20 with the flow rate regulated by the orifice 22 . The compressed air sent to the desiccant 17 flows back through the desiccant 17 from the downstream side to the upstream side of the desiccant 17 . Such a process is a process for regenerating the desiccant 17, and is called a dryer regenerating process. At this time, the dried and cleaned compressed air in the air tank 13 flows back through the desiccant 17 , thereby removing moisture and oil trapped in the desiccant 17 . For example, the regeneration control valve 21 is opened only for a predetermined period. The predetermined period is a period during which the desiccant 17 can be regenerated, and is set logically, experimentally, or empirically.

A branch passage 16 connected to a drain discharge valve 25 is provided between the compressor 4 and the desiccant 17 . A drain outlet 27 is provided at the end of the branch passage 16 .
The drain containing moisture and oil removed from the desiccant 17 is sent to the drain discharge valve 25 together with the compressed air. The drain discharge valve 25 is a pneumatically driven valve, and is provided between the desiccant 17 and the drain discharge port 27 in the branch passage 16 of the air supply passage 18 . The drain discharge valve 25 is a two-port, two-position valve that changes positions between a closed position and an open position. The drain discharge valve 25 sends the drain to the drain discharge port 27 in the open position. The drain discharged from the drain outlet 27 may be collected by an oil separator (not shown).

Drain discharge valve 25 is controlled by governor 26 . The governor 26 is an electromagnetic valve whose operation is switched by turning on/off (driving/non-driving) the power from the ECU 80 via the wiring E62. When the power is turned on, the governor 26 opens the drain discharge valve 25 by inputting an unload signal to the drain discharge valve 25 . When the power is turned off, the governor 26 closes the drain valve 25 by setting the pressure to the atmospheric pressure without inputting the unload signal to the drain valve 25 .

The drain discharge valve 25 is maintained at the closed position when the unload signal of the predetermined air pressure is not input from the governor 26, and becomes the open position when the unload signal is input from the governor 26. Further, when the input port of the drain discharge valve 25 on the compressor 4 side exceeds the upper limit value and becomes high pressure, the drain discharge valve 25 is forcibly switched to the open position.

The compressor 4 is controlled by the governor 26 to switch between load operation in which compressed air is supplied and no-load operation in which compressed air is not supplied. When the power is turned on, the governor 26 sends an unload signal to the compressor 4 to put the compressor 4 into no-load operation. Further, when the power is turned off, the governor 26 does not input an unload signal to the compressor 4 and causes the compressor 4 to operate under load by maintaining atmospheric pressure.

The ECU 80 turns on (drives) the power based on the air pressure detected by the pressure sensor 65 to bring the governor 26 to the supply position where the unload signal is output. Further, the ECU 80 turns off the power (disables driving) based on the air pressure detected by the pressure sensor 65 (see FIG. 1), thereby placing the governor 26 in the non-supply position where the unload signal is not output.

The supply operation, purge operation and regeneration operation of the air dryer 11 will be described with reference to FIG. The supply operation is an operation of supplying compressed air to the air tank 13 . The purge operation is an operation of stopping the compressor for purge processing or the like. The regeneration operation is an operation to regenerate the desiccant 17 . Regeneration and purge operations constitute non-supply operations.

Referring to FIG. 3(a), in the supply operation, the ECU 80 closes the regeneration control valve 21 and the governor 26 (denoted as "CLOSE" in the figure). At this time, the drive signal (power supply) from the ECU 80 is not supplied to the regeneration control valve 21 and the governor 26, respectively. Therefore, the governor 26 opens the port of the compressor 4 and the port of the drain discharge valve 25 connected downstream to the atmosphere. In the supply operation, the compressor 4 supplies compressed air (indicated as “ON” in the figure), and the compressed air supplied to the air dryer 11 (indicated as “IN” in the figure) contains moisture and oil as the desiccant 17 . and supplied to the air tank 13 via the protection valve 12 (denoted as "OUT" in the figure).

Referring to FIG. 3(b), in the purge operation, the ECU 80 closes the regeneration control valve 21 and opens the governor 26 (shown as "OPEN" in the figure). At this time, the governor 26 is supplied with a drive signal (power supply) from the ECU 80 to open the valves, and the port of the compressor 4 and the port of the drain discharge valve 25 connected to the downstream side are moved to the upstream side (protection valves). 12 side). In the purge operation, the compressor 4 is placed in a no-load operation state (represented as "OFF" in the figure) by an unload signal (represented as "CONT" in the figure) from the governor 26, and the inside of the desiccant 17 and the air supply Compressed air in the passage 18 is discharged from the drain outlet 27 together with moisture, oil, and the like.

Referring to FIG. 3(c), in the regeneration operation, the ECU 80 opens the regeneration control valve 21 and the governor 26, respectively. At this time, a drive signal (power supply) from the ECU 80 is supplied to the regeneration control valve 21 and the governor 26 . In the regeneration operation, an unload signal from the governor 26 brings the compressor 4 into a no-load operation state. In the regeneration operation, the regeneration control valve 21 and the drain discharge valve 25 are opened, so that the compressed air on the side of the protection valve 12 reversely flows the desiccant 17 from downstream to upstream, thereby regenerating the desiccant 17. processing takes place. That is, the compressed air that has passed through the desiccant 17 from downstream to upstream is discharged from the drain outlet 27 together with moisture, oil, and the like.

The operation of the air supply system 10 will be described with reference to FIGS. 4-6.
The ECU 80 is provided with a supply start value CI (see FIG. 6), which is the air pressure for starting air supply by the compressor 4, and a supply stop value CO (see FIG. 6), which is the air pressure for stopping the air supply by the compressor 4. ing. Further, the ECU 80 is provided with a reference ventilation amount VO (see FIG. 5) as a reference for the ventilation amount of compressed air. In other words, the reference ventilation amount VO is a ventilation amount suitable for regeneration in a predetermined period. In the ECU 80, as shown in the graph L1 of FIG. 4, an extension time Ta is set which is required for the difference in which the ventilation amount of compressed air exceeds the reference ventilation amount VO. The ECU 80 sets the length obtained by adding the extension time Ta to the predetermined period as the reproduction period. That is, the regeneration period including the extended time Ta may be determined by the ventilation amount of compressed air. In the ECU 80, a recovery amount (aeration amount conversion value) for a predetermined period and a recovery amount (aeration amount conversion value) corresponding to the extension time Ta are set. For example, when the ventilation amount of compressed air exceeds the reference ventilation amount VO, the regeneration time required for the ventilation amount is set by a correction time obtained by interpolation using a map. A regeneration period corrected from a predetermined period is set in the ECU 80 .

For example, the supply stop value CO, the supply start value CI, the reference ventilation amount VO, and the regeneration time map may be stored in the non-volatile storage unit of the ECU 80 or the like. The compressed air flow rate is calculated from the cumulative number of rotations of the compressor 4 and the capacity of the cylinder chamber of the compressor 4 . Also, the ventilation amount is the amount of compressed air discharged from the compressor 4 during the supply operation from before the start of the previous regeneration operation to before the start of the current regeneration operation.

As shown in the graph L1 in FIG. 4, the extension time Ta is proportional to the magnitude of the difference exceeding the reference ventilation amount VO (for example, the difference ΔV1, the difference ΔV2, and the difference ΔV3 in FIG. 5). To increase. The ECU 80 may hold the extension time Ta as a map or a formula.

Referring to graph L3 in FIG. 6, ECU 80 compares the detected air pressure, which is the air pressure detected by pressure sensor 65, with supply start value CI. Then, when the detected air pressure becomes equal to or less than the supply start value CI (time t1), the ECU 80 causes the air dryer 11 to operate to supply compressed air to the air tank 13 . As a result, the governor 26 of the air dryer 11 is closed and the output of the unload signal is stopped. The compressor 4 performs load operation according to the stop of the unload signal (from time t1 to time t21 via time t2). The detected air pressure of the air tank 13 increases as the supply operation of the air dryer 11 continues. Then, the ECU 80 ends the supply operation when the detected air pressure reaches the supply stop value CO (time t21).

Referring to graph L2 in FIG. 5, the ECU 80 performs a regeneration operation when the detected air pressure reaches the supply stop value CO, but the ventilation amount of compressed air does not reach the reference ventilation amount VO (for example, time t21). First, a non-supply operation consisting only of a purge operation is performed. Thus, even if the detected air pressure reaches the supply stop value CO, the ECU 80 repeats the supply operation and the non-supply operation without the regeneration operation until the ventilation amount of the desiccant 17 reaches the reference ventilation amount VO. That is, the air dryer 11 cumulatively increases the amount of compressed air that passes through the desiccant 17 and is dehumidified (ventilation amount) until the regeneration operation is performed (for example, from time t1 to time t5). It should be noted that the ECU 80 resets the ventilation amount of the air dryer 11 by the regeneration operation, or resets it to a predetermined value.

By the way, as shown in the graph L3 of FIG. 6, the air dryer 11 supplies compressed air including the amount consumed by the brake etc. during the supply operation until the air pressure reaches the supply stop value CO (from time t3). until time t5). Therefore, as shown in FIG. 5, even if the ventilation amount exceeds the reference ventilation amount VO, the supply operation continues (from time t4 to time t5), and the dehumidification performance of the desiccant of the air dryer remains degraded. There is a risk. That is, the dehumidification amount of the air dryer 11 exceeds the reference ventilation amount VO by supplying compressed air exceeding the reference ventilation amount VO.

Further, the air dryer 11 is defined to have a range of air pressure for executing the regeneration operation from the supply start value CI to the supply stop value CO. For this reason, the time of the regeneration operation is shortened according to the pressure drop caused by the large amount of compressed air consumed by the brakes, etc. during the regeneration operation, and the regeneration operation can be performed with a smaller amount of regeneration than the amount of regeneration in a predetermined period. finish. That is, even if the regeneration operation is performed, the regeneration amount of the air dryer 11 may be insufficient.

As described above, in the regeneration operation, if the ventilation amount is excessive, the regeneration amount is insufficient for a predetermined period, and if the execution time of the regeneration operation is shortened, the regeneration amount is insufficient. Dehumidification performance may be lowered.

Therefore, as shown in FIG. 5, the ECU 80 detects the ventilation amount from when the reference ventilation amount VO is exceeded until the regeneration operation is started (from time t4 to time t5) as an excess amount ΔV1, and this excess amount ΔV1 The reproduction operation is performed for the time obtained by adding the extension time Ta corresponding to the predetermined period. As a result, the regeneration operation is carried out in such a manner that it includes the time corresponding to the amount of ventilation for the excess ΔV1.

In addition, the ECU 80 acquires the regeneration amount of the desiccant 17 in the regeneration operation based on the recovery amount (in terms of ventilation amount) when the regeneration period is a predetermined period and the recovery amount (in terms of ventilation amount) corresponding to the extended time. do. Then, the ECU 80 subtracts the acquired regeneration amount from the ventilation amount at the start of the regeneration immediately before (time t4) to obtain the unregenerated ventilation amount. It is set as the permeation amount VI1 of the desiccant 17 immediately after the regeneration operation (time t6). For example, the ECU 80 adds the unregenerated ventilation amount to the once reset ventilation amount, so that if there is an unregenerated ventilation amount, the unregenerated ventilation amount remains in resetting the ventilation amount VI1.

Thereafter, when the supply operation ends, the ECU 80 does not perform the regeneration operation and performs the non-supply operation consisting of only the purge operation if the ventilation amount has not reached the reference ventilation amount VO. The ECU 80 accumulates the amount of compressed air that passes through the desiccant 17 and is dehumidified (ventilation amount) when the regeneration operation is not performed. On the other hand, when the ventilation amount exceeds the reference ventilation amount VO, the ECU 80 detects the ventilation amount from when the reference ventilation amount VO is exceeded until the regeneration operation is started, for example, as the excesses ΔV2 and ΔV3. Then, the ECU 80 adds the extension time Ta corresponding to the excesses ΔV2 and ΔV3 to the predetermined period to obtain the regeneration period. As a result, the dehumidification performance of the desiccant 17 is regenerated with a regeneration amount corresponding to the aeration amount obtained by adding the normal aeration amount and the aeration amounts corresponding to the excesses ΔV2 and ΔV3.

Further, the ECU 80 resets the ventilation amounts VI2 and VI3 after the regeneration operation. The ECU 80 calculates the ventilation amount corresponding to the regeneration operation. The ventilation amount includes the regeneration amount (ventilation amount equivalent value) corresponding to the predetermined period and the regeneration amount (ventilation amount equivalent value) corresponding to the extended time Ta. The ECU 80 acquires the reset ventilation amounts VI2 and VI3 by subtracting the regeneration amount corresponding to the regeneration operation from the value of the ventilation amount of the desiccant 17 at the start of the regeneration immediately before.

As described above, according to this embodiment, the following effects can be obtained.
(1) The length of the regeneration period is adjusted for a given period based on the amount of compressed air in the supply operation. As a result, deterioration in the performance of the air dryer in the air supply system can be suppressed.

(2) The length of the regeneration period is adjusted based on the ventilation rate of the compressed air.
(3) The length of the predetermined period can be adjusted based on a comparison of the ventilation rate and the reference ventilation rate.

(4) The regeneration period is adjusted based on the regeneration start air pressure detected by the pressure sensor.
(5) The amount of ventilation that is insufficiently regenerated during the regeneration period (unregenerated amount) is added to the next amount of ventilation, so that insufficient regeneration is not cumulatively accumulated.

It should be noted that the above embodiment can be implemented with the following modifications. The above embodiments and the following modifications can be combined with each other within a technically consistent range.

- The air tank 13 may supply compressed air to a device that consumes compressed air other than the brake valve 14, such as a parking brake.
The pressure sensor 65 may detect the air pressure at any position downstream of the check valve 19 as long as it can detect the air pressure corresponding to the air pressure in the air tank 13 . For example, a pressure sensor may detect air pressure within an air tank. Thereby, it may be possible to control the supply operation, the non-supply operation, and the regeneration operation based on the detected air pressure in the air tank.

- In the above embodiment, the reproduction period is obtained by adding the extension time Ta to the predetermined period, but the reproduction period may be obtained by subtracting the shortened time from the predetermined period. For example, with respect to the shortage of the ventilation amount, which is a region obtained by extending the graph L1 in FIG. .

・In the above embodiment, the case where the ventilation amount is calculated from the cumulative number of revolutions of the compressor 4 and the capacity of the cylinder chamber was exemplified. can be measured by

- In the above embodiment, the case where the regeneration period is extended according to the excess ventilation amount at the start of the regeneration operation was exemplified. The reproduction operation may be performed during the reproduction period. At this time, by subtracting the ventilation amount corresponding to the normal regeneration period from the ventilation amount at the start of the regeneration operation, the ventilation amount for the unregenerated portion may be taken over to the next time. By taking over the unregenerated amount in the aeration amount, the aeration amount until the next regeneration is reduced, so that the performance deterioration of the desiccant can be suppressed.

- If the ventilation amount at the start of regeneration is less than a predetermined value (reference ventilation amount VO), the regeneration time may be shortened.
Also, if the air pressure at the start of regeneration is less than the supply stop value CO, the regeneration time may be lengthened.

- In the above-described embodiment, the desiccant 17 is provided, but a filter may be provided.
- Although the case where the desiccant 17 is provided has been illustrated in the above embodiment, the oil mist separator may be provided upstream of the desiccant 17 without being limited thereto.

The oil mist separator has a desiccant that separates gas and liquid by collision with the compressed air, and captures oil contained in the compressed air sent from the compressor 4 . The desiccant may be a compression-molded metal material or a porous material such as sponge. By providing this oil mist separator, the cleaning performance of the compressed air can be further enhanced.

- In the above-described embodiment, the air supply system 10 is described as being mounted on an automobile such as a truck, a bus, or a construction machine. Alternatively, the air supply system may be installed in other vehicles such as passenger cars and railroad vehicles.

4 Compressor 10 Air supply system 11 Air dryer 11A Interior 12 Protection valve 13 Air tank 14 Brake valve 4E, 11E, 12E, 13E, 14E Air supply path 15 Brake chamber , 16... branch passage, 17... desiccant, 18... air supply passage, 19... check valve, 20... bypass flow path, 21... regeneration control valve, 22... orifice, 25... drain discharge valve, 26... governor, 27... Drain outlet 65 Pressure sensor 66 Temperature and humidity sensor 80 ECU 100 Vehicle ECU E62, E63, E65, E66 Wiring P12 Maintenance port.

Claims (3)

a desiccant for removing moisture from the compressed air delivered from the compressor ;
a check valve that allows air to flow from the desiccant in a direction opposite to the compressor ;
A regeneration control valve provided in the middle of a bypass passage parallel to the check valve, wherein the regeneration control valve seals the bypass passage when the valve is closed and communicates the bypass passage when the valve is opened. An air supply system that performs a supply operation to flow the compressed air from upstream to downstream via an air dryer,
A regeneration operation of switching between the supply operation and the non-supply operation , and opening the regeneration control valve during the non-supply operation to allow the compressed air to flow from the downstream to the upstream to regenerate the desiccant. a control device including
The controller controls that the amount of compressed air in the supply operation from before the start of the previous regeneration operation to before the start of the current regeneration operation is greater than a reference ventilation amount that is an amount of ventilation suitable for regeneration in a predetermined period. Depending on the situation, the regeneration period, which is the length of time during which the regeneration operation is performed, is adjusted to be longer than the predetermined period . an air supply system that adjusts the life duration to be shorter than the predetermined duration . 2. The air supply system according to claim 1, wherein the control device is capable of acquiring the rotation speed of the compressor, and acquires the ventilation amount based on the rotation speed of the compressor. a desiccant for removing moisture from the compressed air delivered from the compressor ;
a check valve that allows air to flow from the desiccant in a direction opposite to the compressor ;
A regeneration control valve provided in the middle of a bypass passage parallel to the check valve, wherein the regeneration control valve seals the bypass passage when the valve is closed and communicates the bypass passage when the valve is opened. An air supply system that performs a supply operation to flow the compressed air from upstream to downstream via an air dryer,
A regeneration operation of switching between the supply operation and the non-supply operation , and opening the regeneration control valve during the non-supply operation to allow the compressed air to flow from the downstream to the upstream to regenerate the desiccant. a control device including
The control device resets the ventilation amount of the compressed air after the supply operation is started in response to the start of the regeneration operation, and the ventilation amount before the reset and the predetermined amount at which the regeneration operation is performed are adjusted. an air supply system that adds a difference from a reference ventilation amount, which is an ventilation amount suitable for regeneration in the period of , to the ventilation amount after the reset.

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