JP2020104069A - Air supply system - Google Patents

Abstract

To provide an air supply system that can suppress deterioration in performance of an air dryer.SOLUTION: An air supply system 10 performs supply operation by which compressed air is flown from an upstream to a downstream through an air drier 11 having a desiccant 17 and a check valve 19. The air supply system 10 comprises: a pressure sensor that detects air at a downstream of the check valve 19; and an ECU 80 that switches between the supply operation and non-supply operation, where the non-supply operation includes regeneration operation of regenerating the desiccant 17. The ECU 80 performs the regeneration operation for a first prescribed period of time after starting the non-supply operation. The ECU 80 further executes the regeneration operation temporarily for a second prescribed period of time, in the middle of the supply operation, and when detected air pressure by the pressure sensor is lower than a supply stoppage value at which the non-supply operation is started and when a temporary execution condition is satisfied.SELECTED DRAWING: Figure 2

Description

The present invention relates to an air supply system that supplies compressed air to equipment.

In vehicles such as trucks, buses, and construction machines, compressed air sent from a compressor is used to control pneumatic systems such as brakes and suspensions. The compressed air contains liquid impurities such as water contained in the atmosphere and oil that lubricates the inside of the compressor. If compressed air containing a large amount of water or oil enters the pneumatic system, it causes rust or swelling of the rubber member, causing malfunction. Therefore, an air dryer that removes impurities such as water and oil in the compressed air is provided downstream of the compressor.

The air dryer performs a dehumidifying operation for removing oil and water and a regenerating operation for removing oil and water adsorbed on the desiccant and discharging the oil and water as drain. For example, Patent Document 1 describes a technique for an air dryer to perform a reproducing operation.

The air supply system described in Patent Document 1 stores air compressed by a compressor in an air tank. When the air pressure in the air tank is equal to or lower than the first pressure, the compressor is driven to supply the compressed air to the air tank until the air pressure rises and reaches the second pressure. When the air pressure reaches the second pressure, the supply of compressed air to the air tank by the compressor is stopped and the discharge valve (purge valve) is opened. After that, the regenerating operation is performed in which the compressed air in the air tank is passed through the air dryer and discharged to the atmosphere by maintaining the valve open state until the air pressure decreases to the third pressure. Then, when the air pressure in the air tank reaches the third pressure, the discharge valve is closed.

JP, 2005-229127, A

By the way, on a downhill with a long distance or a long traffic jam, a large amount of compressed air in the air tank is consumed by a brake or the like even during the supply operation in which the compressor supplies compressed air to the air tank. For example, the technique described in Patent Document 1 increases the air pressure of the air tank from the first pressure to the second pressure by supplying compressed air including the amount consumed by the brake or the like by the supply operation. Therefore, in the air dryer, the dehumidifying operation may continue without performing the regenerating operation until the air pressure in the air tank reaches the second pressure, and the dehumidifying performance may deteriorate.

The present invention has been made in view of such circumstances, and an object thereof is to provide an air supply system capable of suppressing the 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 of flowing compressed air from a compressor through an air dryer having a desiccant and a check valve to a downstream side, and a downstream of the check valve. A pressure sensor for detecting the air pressure, a control device including a regeneration operation for switching the supply operation and the non-supply operation and regenerating the desiccant in the non-supply operation, and the control device includes the regeneration operation. Is performed for a first predetermined period after the non-supply operation is started, and the control device is in the middle of the supply operation, and the detected air pressure detected by the pressure sensor starts the non-supply operation. When it is lower than the supply stop value and when the temporary execution condition is satisfied, the regeneration operation is temporarily executed for the length of the second predetermined period.

According to such a configuration, since the temporary execution condition is satisfied, the reproducing operation can be temporarily executed for the length of the second predetermined period even during the supply operation. For example, when the supply operation continues for a long time, the regeneration operation is performed during the supply operation due to the establishment of the temporary execution condition, and the dehumidifying performance of the air dryer can be recovered to some extent. As a result, it is possible to prevent the performance of the air dryer from deteriorating.

As a preferred configuration, the control device sets the second predetermined period to be shorter than the first predetermined period.
With such a configuration, by shortening the period of the regenerating operation performed during the supply operation due to the establishment of the temporary execution condition to be shorter than the period of the regenerating operation performed during the non-supply operation, consumption of compressed air by the regenerating operation is performed. Can be suppressed, and the supply operation can be restored in a short time.

As a preferred configuration, the temporary execution condition includes that the duration of the supply operation is longer than a third predetermined period.
With such a configuration, the temporary execution condition is satisfied on the basis that the duration of the supply operation is longer than the third predetermined period. For example, the third predetermined period is preferably set longer than the time normally required from the start to the end of the supply operation.

As a preferred configuration, the control device includes a re-execution period shorter than the third predetermined period, and the temporary execution condition is the supply after the reproduction operation executed based on the establishment of the temporary execution condition. The duration of the operation is longer than the re-execution period.

With such a configuration, even when the supply operation is continued for a long time, the reproduction operation can be temporarily executed a plurality of times.
As a preferred configuration, the temporary execution condition includes that the supply amount of the compressed air in the supply operation is larger than a predetermined amount, and corresponds to the reproduction process by the reproduction operation executed based on the establishment of the temporary execution condition. The supply amount to be supplied is subtracted from the supply amount of the compressed air.

According to such a configuration, the temporary execution condition is satisfied on the basis that the supply amount of the compressed air in the supply operation is larger than the predetermined amount. For example, it is preferable that the predetermined amount is set to be larger than the supply amount normally required from the start to the end of the supply operation. Further, by subtracting the supply amount corresponding to the reproduction process by the temporarily executed reproduction operation from the supply amount of the compressed air, it is possible to suppress the reproduction shortage while reducing the reproduction amount.

As a preferred configuration, the control device stops the supply operation during the second predetermined period.
With such a configuration, the supply operation is stopped even during the temporary regeneration operation, so that the regeneration by the reverse flow of the compressed air is efficiently performed.

According to the present invention, it is possible to suppress the performance deterioration of the air dryer.

The block diagram which shows the schematic structure of one Embodiment of the air supply system used for the pneumatic system. The block diagram which shows schematic structure of the air supply system in the same embodiment. FIG. 4 is a diagram showing an operation mode of the air dryer in the same embodiment, (a) is a diagram showing a supply action, (b) is a diagram showing a purge action, and (c) is a diagram showing a regenerating action. The graph which shows an example of the time change of the air pressure of the compressed air in the air tank in the embodiment. The graph which shows an example of the time change of the ventilation volume of the compressed air dehumidified by the air dryer in other embodiment of the air supply system used for the pneumatic system.

An embodiment of an air supply system included in a pneumatic system will be described with reference to FIGS. 1 to 4. The air supply system is installed in automobiles such as trucks, buses, and construction machines.

An outline 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 respective air supply passages 4E, 11E, 12E, 13E, 14E. Of these, the compressor 4, the air dryer 11, and the protection valve 12 constitute an air supply system 10.

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

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 clean the compressed air. The compressed air thus purified is supplied from the air dryer 11 to the air tank 13 via the air supply passage 11E, the protection valve 12 and the air supply passage 12E.

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

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 wirings E62 and E63. Further, the ECU 80 is electrically connected to the pressure sensor 65 via the wiring E65. The 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 of the air tank 13 from the detection signal of the pressure sensor 65. The ECU 80 is electrically connected to the temperature/humidity sensor 66 via a 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. Further, the ECU 80 is electrically connected to the vehicle ECU 100 so as to obtain various signals of the vehicle equipped with the air supply system 10.

The ECU 80 includes a calculation unit, a volatile storage unit, and a non-volatile storage unit, and gives signals to the air dryer 11 to instruct various operations in accordance with a program stored in the non-volatile 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 at the time of maintenance.

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

The desiccant 17 is silica gel, zeolite, or the like, and removes water contained in the compressed air to dry it by passing compressed air, and also removes oil contained in the compressed air to clean the air. The 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 only the flow of air downstream from the desiccant 17. That is, the check valve 19 allows only the flow of air from upstream to downstream when the desiccant 17 is located upstream and the protection valve 12 is located 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 passage 20.

The regeneration control valve 21 is an electromagnetic valve whose operation is switched by turning on/off (driving/not driving) the power from the ECU 80 via the wiring E63. The regeneration control valve 21 is closed when the power is off to seal the bypass passage 20, and is opened when the power is on to connect the bypass passage 20. For example, the regeneration control valve 21 is driven when the value of the detected air pressure exceeds the supply stop value.

The bypass passage 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 passage 20 in a state where the flow rate is regulated by the orifice 22. The compressed air sent to the desiccant 17 flows backward 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, so that the moisture and oil components captured by the desiccant 17 are removed from the desiccant 17. For example, the regeneration control valve 21 is opened for a predetermined period. The predetermined period is a period in which the desiccant 17 can be regenerated, and is set logically, experimentally or empirically.

A branch passage 16 connected to the 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 water 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 that is driven by air pressure, 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 2-port 2-position valve that changes its position between a closed position and an open position. The drain discharge valve 25 sends the drain to the drain discharge port 27 at the open position. The drain discharged from the drain outlet 27 may be collected by an oil separator (not shown).

The drain discharge valve 25 is controlled by the governor 26. The governor 26 is a solenoid valve whose operation is switched by turning on and off (driving/non-driving) the power from the ECU 80 via the wiring E62. When the power is turned on, the governor 26 inputs the unload signal to the drain discharge valve 25 to open the drain discharge valve 25. Further, when the power is turned off, the governor 26 closes the drain discharge valve 25 by setting the atmospheric pressure without inputting the unload signal to the drain discharge valve 25.

The drain discharge valve 25 is maintained in the valve closed position in the state where the unload signal of the predetermined air pressure is not input from the governor 26, and is in the valve open position when the unload signal is input from the governor 26. Further, when the input port on the compressor 4 side of the drain discharge valve 25 exceeds the upper limit value and becomes high in 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 a load operation in which compressed air is supplied and a 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 a no-load operation. When the power is turned off, the governor 26 does not input an unload signal to the compressor 4 to bring it to atmospheric pressure, thereby causing the compressor 4 to operate under load.

The ECU 80 turns on (drives) the power source 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 supply (sets it into a non-driving state) based on the air pressure detected by the pressure sensor 65, thereby placing the governor 26 in the non-supply position where the unload signal is not output.

A supply operation, a purging operation, and a regenerating 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 purging operation is an operation in which the compressor is stopped for purging processing or the like. The regenerating operation is an operation of regenerating the desiccant 17. The regeneration operation and the purging operation constitute a non-supplying operation.

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

Referring to FIG. 3B, in the purging operation, the ECU 80 closes the regeneration control valve 21 and opens the governor 26 (indicated as "OPEN" in the figure). At this time, the governor 26 opens when a drive signal (power source) from the ECU 80 is supplied, and the port of the compressor 4 and the port of the drain discharge valve 25, which are connected to the downstream side, are respectively connected to the upstream side (protection valve). 12 side). In the purging operation, the unload signal from the governor 26 (described as “CONT” in the figure) causes the compressor 4 to be in the no-load operation state (described as “OFF” in the figure), and the interior of the desiccant 17 and the air supply. The compressed air in the passage 18 is discharged from the drain discharge port 27 together with water, oil and the like.

Referring to FIG. 3C, 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 source) from the ECU 80 is supplied to the regeneration control valve 21 and the governor 26. In the regenerating operation, the unload signal from the governor 26 puts the compressor 4 into a no-load operation state. Further, in the regeneration operation, the regeneration control valve 21 and the drain discharge valve 25 are opened, whereby the compressed air on the side of the protection valve 12 flows back the desiccant 17 from the downstream side to the upstream side, and the desiccant 17 is regenerated. Processing is performed. That is, the compressed air that has flowed through the desiccant 17 from the downstream side to the upstream side is discharged from the drain discharge port 27 together with water, oil, and the like.

The operation of the air supply system 10 will be described with reference to FIG.
The ECU 80 stores various parameters in a non-volatile storage unit or the like. For example, the ECU 80 stores a supply start value CI that is the air pressure that starts the air supply by the compressor 4 and a supply stop value CO that is the air pressure that stops the air supply by the compressor 4. Further, the ECU 80 stores a temporary reproducible value CR that is less than the supply stop value CO and higher than the supply start value CI. Further, the ECU 80 stores a first predetermined period Rt1 which is a period of a normal reproduction operation and a second predetermined period Rt2 which is a period of a temporary reproduction operation. The ECU 80 also stores a supply period th1, a temporary regeneration start period th2, and a re-execution period th3. The supply period th1 is a normal period in which the supply operation is continued because the detected air pressure reaches the supply stop value CO. The temporary reproduction start period th2 is a period for determining that the duration of the reproduction operation is a period necessary for performing the temporary reproduction operation. The re-execution period th3 is a continuation period of the reproduction operation that is shorter than the temporary reproduction start period th2.

As shown in the graph L1 of FIG. 4, the ECU 80 compares the detected air pressure, which is the air pressure detected by the pressure sensor 65, with the supply start value CI. When the detected air pressure becomes equal to or lower than the supply start value CI (time t0), the ECU 80 causes the air tank 13 to supply compressed air, and thus causes the air dryer 11 to perform a supply operation. 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 in response to the stop of the unload signal. In the air tank 13, the detected air pressure rises as the supply operation of the air dryer 11 continues (from time t0 to time t1).

At this time, as shown in the graph L2 of FIG. 4, normally, the supply corresponding to time t0 to time t2, which is the time until the air pressure of the compressed air during the supply operation reaches the supply stop value CO. The supply operation is continued during the period th1. When the supply stop value CO is reached, the regeneration operation is performed for the first predetermined period Rt1 after the non-supply operation is started. The first predetermined period Rt1 is necessary for recovering (regenerating) the dehumidification performance of the desiccant 17, which has been reduced due to the dehumidification treatment of the supply amount of compressed air normally required to reach the supply stop value CO. Is the period. The first predetermined period Rt1 can be set experimentally, theoretically, or empirically.

However, in the present embodiment, since the vehicle is traveling on a long downhill, a long traffic jam, etc., a large amount of compressed air in the air tank 13 is consumed by the brake chamber 15 and the like. Therefore, the air pressure of the compressed air in the air tank 13 is maintained in a reduced state (from time t1 to time t3) even though the compressor 4 is in the supply operation of supplying the compressed air to the air tank 13. Then, as the time t3 approaches, the detected air pressure increases due to the continuous supply operation of the air dryer 11 (before the time t3). At this time, normally, even though the supply period th1 in which the regenerating operation is performed exceeds the dehumidifying performance, the desiccant 17 is supposed to be continuously dehumidified without being regenerated. Remains low. When the desiccant 17 is continuously used while the dehumidifying performance is still lowered, the dehumidifying performance tends to be further deteriorated.

Therefore, the ECU 80 temporarily executes the regenerating operation in order to reduce the continuous use of the desiccant 17 in a state where the dehumidifying performance is lowered. More specifically, the temporary regeneration operation is in the middle of the supply operation, when the detected air pressure is lower than the supply stop value CO, and when the temporary execution condition is satisfied, the second predetermined period Rt2. Executed in the length of. Here, the temporary execution condition is satisfied when the duration of the supply operation is longer than the temporary reproduction start period th2 as the third predetermined period which is longer than the supply period th1 (time t3). As a result, the continuous use of the desiccant 17 in a state where the dehumidifying performance is lowered is reduced, and the deterioration of the dehumidifying performance of the desiccant 17 is suppressed. In the temporary regeneration operation, the air dryer 11 is in the regeneration operation, so that the compressor 4 is in the non-supply operation (non-driving state). As a result, the compressed air appropriately flows back through the desiccant 17, so that the regenerating operation is efficiently performed. Further, since unnecessary supply operation is suppressed, fuel consumption associated with the operation of the compressor 4 can be reduced.

When the regeneration operation is performed temporarily (time t3), the detected air pressure is lower than the supply stop value CO, so it is preferable to suppress the consumption of compressed air. Therefore, the second predetermined period Rt2 (time t3), which is a period in which the reproducing operation is temporarily performed, is shorter than the first predetermined period Rt1, which is a period in which the normal reproducing operation is performed.

The temporary execution condition may further include that the detected air pressure is equal to or higher than the temporarily reproducible value CR. The temporarily reproducible value CR is lower than the supply stop value CO and higher than the supply start value CI. If the detected air pressure is less than the temporarily reproducible value CR (for example, at time t2 or before and after the time t2), the ECU 80 increases the relative ratio of the amount of compressed air consumed by the temporary regenerating operation to the remaining amount of compressed air. Therefore, the temporary reproduction operation is not performed.

Further, the temporary execution condition may be satisfied when the period during which the reproducing operation is not performed after the temporary reproducing operation has passed the re-execution period th3. That is, the ECU 80 performs a temporary regeneration operation (time t4) and then continues the supply operation (time t5), but does not perform the regeneration operation (from time t4 to time t6). ) Executes the re-execution period th3, the temporary reproduction operation is executed for the length of the second predetermined period Rt2 (from time t6 to time t7).

This also reduces the continuous use of the desiccant 17 in a state where the dehumidifying performance is lowered, and suppresses the progress of the deterioration of the dehumidifying performance of the desiccant 17.
As described above, according to this embodiment, the following effects can be obtained.

(1) When the temporary execution condition is satisfied, even if the air dryer 11 is in the middle of the supplying operation, the reproducing operation is temporarily executed for the length of the second predetermined period Rt2. For example, when the supply operation continues for a long time, the regeneration operation is performed during the supply operation due to the establishment of the temporary execution condition, and the dehumidifying performance of the air dryer 11 (desiccant 17) can be recovered to some extent. This can prevent the performance of the air dryer 11 from deteriorating.

(2) The second predetermined period Rt2, which is the period of the reproducing operation performed during the supply operation due to the establishment of the temporary execution condition, is the first period, which is the period of the reproducing operation (normal reproduction operation) performed during the non-supply operation. Since it is shorter than the predetermined period Rt1, consumption of compressed air due to the regeneration operation can be suppressed, and the supply operation can be restored in a short time.

(3) The temporary execution condition is satisfied on the basis that the duration of the supply operation is longer than the temporary regeneration start period th2. For example, it is preferable that the temporary reproduction start period th2 is set longer than the time normally required from the start to the end of the supply operation.

(4) Since the temporary execution condition is satisfied because the duration of the supply operation is longer than the re-execution period after the temporary reproduction operation, even if the supply operation is continued for a long time, the reproduction operation is temporarily stopped. Can be performed multiple times.

(5) Since the supply operation is stopped even during the temporary regeneration operation, the regeneration by the reverse flow of the compressed air is efficiently performed.
The present embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

In the above embodiment, when the temporary execution condition is satisfied when the duration of the supply operation is longer than the temporary reproduction start period th2, or when the reproduction operation is not performed after the temporary reproduction operation is performed, The case where it is established when the re-execution period th3 has been included is illustrated. However, the present invention is not limited to this, and the temporary execution condition may be established based on the amount of compressed air flowing through the desiccant 17 from the upstream side to the downstream side. The ventilation amount here is a cumulative ventilation amount.

This will be described with reference to the graph L3 in FIG. The ventilation amount of the desiccant 17 is an index for determining the deterioration of the desiccant 17, and is normally reset by performing the regeneration operation, or the ventilation amount corresponding to the regeneration amount is subtracted. Therefore, if the regenerating operation is performed regularly, the ventilation amount does not reach the dehumidification upper limit amount VO, and is reset or decreases before reaching. The dehumidification upper limit amount VO is the maximum value of the ventilation amount with which the desiccant 17 can exhibit appropriate dehumidification performance.

However, in this modified example, the vehicle is on a downhill with a long distance, a long traffic jam, and the like, and a large amount of compressed air in the air tank 13 is consumed by the brake chamber 15 and the like. Therefore, although the compressor 4 continues the supply operation (from time t10 to time t11), the regeneration operation is not executed during that time, and the ventilation amount reaches the dehumidification upper limit amount VO (time t11). Further, by continuing the supply operation, the supply amount reaches the temporary regeneration start amount VLO, which is larger than the predetermined amount (time t12). In the ECU 80, the temporary execution condition is satisfied in response to the temporary regeneration start amount VLO being reached. That is, the ECU 80 determines that the temporary operation condition is satisfied when the supply air is in the middle of the supply operation, the detected air pressure is lower than the supply stop value CO, and the temporary regeneration operation is performed by the second operation. The process is executed for the length of the predetermined period Rt2 (time t12 to time t13). As a result, the continuous use of the desiccant 17 in a state where the dehumidifying performance is lowered is reduced, and the deterioration of the dehumidifying performance of the desiccant 17 is suppressed.

When performing the temporary regeneration operation, the ECU 80 subtracts the corresponding amount ΔV1 corresponding to the supply amount recovered by the regeneration operation from the ventilation amount of the compressed air (time t12).
Then, after that, the supply amount increases again (from time t13 to time t14) and reaches the temporary regeneration start amount VLO (time t14), so that the temporary execution condition is satisfied, so that the ECU 80 temporarily operates. The reproduction operation is executed for the length of the second predetermined period Rt2 (time t14 to time t15). The temporary execution condition is satisfied when the supply amount reaches the temporary regeneration start amount VLO. Then, when performing a temporary regeneration operation, the ECU 80 subtracts the corresponding amount ΔV1 corresponding to the supply amount recovered by the regeneration operation from the ventilation amount of the compressed air (time t14).

At this time, since the corresponding amount ΔV1 is smaller than the amount corresponding to the ventilation amount recovered in the normal regeneration operation, the compressed air is supplied by the corresponding amount ΔV1 until the normal regeneration operation is performed, and the supply amount is reduced. A temporary playback operation may be performed each time when reaches the temporary playback start amount VLO.

This also reduces the continuous use of the desiccant 17 in a state where the dehumidifying performance is lowered, and suppresses the deterioration of the dehumidifying performance of the desiccant 17.
In the above modification, when the supply amount reaches the temporary regeneration start amount VLO which is larger than the predetermined amount, the length of the second predetermined period Rt2 for performing the temporary regeneration operation is changed according to the air pressure of the air tank 13. You may.

The air tank 13 may supply the compressed air to a device other than the brake valve 14 that consumes the compressed air, 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 of the air tank 13. For example, the pressure sensor may detect the air pressure in the 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-described embodiment, the desiccant 17 is configured to include the desiccant and the filtering unit, but the desiccant 17 may be configured to include any one of them.
-In the said embodiment, although the case where the desiccant 17 was provided was illustrated, it is not restricted to this and an oil mist separator may be provided upstream of the desiccant 17.

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

Although the period of the reproduction operation performed after the re-execution period th3 is the second predetermined period Rt2 is illustrated, the period of the reproduction operation is not limited to this and may be shorter than the second predetermined period Rt2. It may be longer or, conversely, longer. If it is shortened, the amount of regeneration is small but the consumption of compressed air is suppressed. Conversely, if the length is increased, the amount of compressed air consumed increases, but the amount of regeneration of the desiccant 17 increases and the progress of deterioration can be suppressed.

In the above embodiment, the air supply system 10 has been described as being installed in an automobile such as a truck, a bus, and a construction machine. As an aspect other than this, the air supply system may be mounted in another vehicle such as a passenger car or a railroad vehicle.

4... Compressor, 10... Air supply system, 11... Air dryer, 11A... Inside, 12... Protective 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 passage, 21... Regeneration control valve, 22... Orifice, 25... Drain discharge valve, 26... Governor, 27... Drain discharge port, 65... Pressure sensor, 66... Temperature and humidity sensor, 80... ECU, 100... Vehicle ECU, E62, E63, E65, E66... Wiring, P12... Maintenance port.

Claims (6)

An air supply system that performs a supply operation of flowing compressed air from a compressor through an air dryer having a desiccant and a check valve, from an upstream side to a downstream side,
A pressure sensor for detecting the air pressure downstream of the check valve,
A supply device and a control device including a regenerating operation for regenerating the desiccant in the non-supplying operation by switching between the non-supplying operation,
The control device performs the reproduction operation for a first predetermined period after the non-supply operation is started,
The control device is further in the middle of the supply operation, and when the detected air pressure detected by the pressure sensor is lower than a supply stop value for starting the non-supply operation, and when a temporary execution condition is satisfied, An air supply system for temporarily executing the regeneration operation for a length of a second predetermined period. The air supply system according to claim 1, wherein the control device sets the second predetermined period to be shorter than the first predetermined period. The air supply system according to claim 1, wherein the temporary execution condition includes that the duration of the supply operation is longer than a third predetermined period. The control device includes a re-execution period shorter than the third predetermined period,
The air supply system according to claim 3, wherein the temporary execution condition includes that the duration of the supply operation is longer than the re-execution period after the regeneration operation executed based on the satisfaction of the temporary execution condition. .. The temporary execution condition includes that the supply amount of the compressed air in the supply operation is larger than a predetermined amount,
The air supply system according to any one of claims 1 to 4, wherein the supply amount corresponding to the regeneration processing by the regeneration operation performed based on the establishment of the temporary execution condition is subtracted from the supply amount of the compressed air. .. The air supply system according to any one of claims 1 to 5, wherein the control device stops the supply operation during the second predetermined period.