JP2021160366A - Purge system and vehicle - Google Patents

Abstract

To provide a purge system capable of extending the life of the desiccant of an air dryer.SOLUTION: A purge system includes: an air dryer; a purge control valve controlled in either of a first control mode in which to start supplying instruction pressure when tank pressure being the pressure inside a main tank has reached a first pressure value and to stop the supply of the instruction pressure when the tank pressure has decreased to a second pressure value being smaller than the first pressure value, and a second control mode in which to stop the supply of the instruction pressure regardless of the tank pressure; and a control part for switching to the second control more from the first control mode in a case where at least any of the following conditions is met, i.e., a given operation is detected, an air supply volume by the compressor in a given period is determined to be equal to or more than a first threshold, and a period of time from a clock time when the supply of instruction pressure has been started by the purge control valve to a clock time when the supply of instruction pressure has been stopped by the purge control valve is shorter than a reference time.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to purge systems and vehicles.

In a system that supplies air used for the operation of air equipment such as an air brake (for example, Patent Document 1), air compressed by an air compressor is sent to an air dryer, and moisture and oil content in the compressed air in the air dryer is sent. Is removed, and the air from which water and oil have been removed is stored in the tank. A desiccant is provided inside the air dryer, and the desiccant removes water and oil in the air flowing into the air dryer.

The air dryer disclosed in Patent Document 1 includes a purge valve, and when air is supplied from the tank to the purge valve, the purge valve is opened and the inside of the air dryer is opened to the atmosphere. As a result, when the dried air inside the air dryer moves toward the atmosphere, the desiccant is regenerated by removing the water and oil absorbed by the desiccant in the air dryer.

Japanese Unexamined Patent Publication No. 8-301100

In the system disclosed in Patent Document 1, a pressure governor is provided in the pipe connecting the tank and the purge valve, and the pressure governor is used as a purge valve when the pressure in the tank becomes relatively high. Supply air.

When the amount of air used in the tank by the air equipment is large, the amount of air in the tank is unlikely to increase. Therefore, it takes a long time for the pressure in the tank to reach the pressure at which the pressure governor starts supplying air to the purge valve, so that the time when the desiccant is not regenerated in the air dryer is prolonged. Therefore, the desiccant tends to deteriorate, and as a result, the life of the desiccant in the air dryer may be shortened.

The present disclosure has been made in consideration of the above points, and an object of the present disclosure is to provide a purging system and a vehicle equipped with a purging system capable of extending the life of the desiccant of an air dryer.

One aspect of the purge system of the present disclosure includes a main tank, a compressor for discharging air, a purge valve, an air dryer for supplying the air discharged from the compressor to the main tank, and the inside of the main tank. When the tank pressure, which is the pressure of, reaches the first pressure value, the supply of the indicated pressure from the main tank to the purge valve is started, and the tank pressure is smaller than the first pressure value. It is controlled in either a first control mode in which the supply of the indicated pressure is stopped when the value drops to a value, or a second control mode in which the indicated pressure is supplied regardless of the tank pressure. It is determined that the purge control valve and the purge control valve are controlled and a predetermined operation is detected, and that the amount of air supplied to the air dryer by the compressor in a predetermined period is equal to or higher than the first threshold value. And, when at least one of the time from the time when the purge control valve starts supplying the indicated pressure to the time when the purge control valve stops supplying the indicated pressure is less than the reference time is satisfied. A control unit that switches the control mode of the purge control valve from the first control mode to the second control mode is provided.

One aspect of the vehicle of the present disclosure comprises the purge system described above.

According to the present disclosure, it is possible to provide a vehicle equipped with a purge system and a purge system capable of extending the life of the desiccant of the air dryer.

The figure which shows the main structure of the purge system provided in the vehicle which concerns on embodiment The figure explaining the drive start and drive stop of the compressor executed by the purge system according to the embodiment. A flowchart showing a control example of a purge control valve executed by the purge system according to the embodiment. Flow chart showing a control example of the purge control valve executed by the purge system according to the first modification The figure which shows the purge control valve provided in the purge system which concerns on modification 2. The figure which shows the purge control valve provided in the purge system which concerns on modification 2. The figure which shows the main structure of the purge system which concerns on modification 3.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

<Structure>
FIG. 1 is a diagram showing a main configuration of a purge system 1 included in a vehicle 100 according to an embodiment of the present disclosure. Hereinafter, the vehicle 100 will be described as being a large vehicle such as a bus or a truck.

The purge system 1 includes a compressor 11, a motor 12, an air dryer 13, a main tank 14, a purge control valve 16, a pressure sensor 17, a flow rate sensor 41, a stop operation detection unit 42, an instruction operation detection unit 43, and a control unit 60. ing.

The compressor 11 discharges the sucked air at a desired flow rate, and supplies the discharged air to the air dryer 13. The compressor 11 is an electric compressor driven by a motor 12.

The motor 12 drives the compressor 11 at a predetermined rotation speed under the control of the control unit 60.

The air dryer 13 removes water and oil contained in the air discharged from the compressor 11, and supplies the removed air to the main tank 14.

A desiccant D is arranged inside the air dryer 13. The desiccant D absorbs water and oil in the air that has flowed into the air dryer 13.

The air dryer 13 includes a purge valve 131, and when an indicated pressure is supplied to the purge valve 131, the air dryer 13 executes a regeneration process of the desiccant D, a so-called purge process. Here, the indicated pressure is air that triggers the air dryer 13 to execute the purge process, and is supplied from the main tank 14.

When the indicated pressure is supplied to the purge valve 131, the purge valve 131 is opened and the inside of the air dryer 13 is opened to the atmosphere. Then, the dry air inside the air dryer 13 removes the water and oil components absorbed by the desiccant D when it is discharged to the atmosphere. As a result, the desiccant D is regenerated.

The main tank 14 stores air from which water and oil have been removed by the air dryer 13. The air stored in the main tank 14 is supplied to air equipment (not shown) such as air brakes, air suspensions, equipment related to opening and closing doors, and equipment related to kneeling operation at appropriate timings.

The purge control valve 16 is a solenoid valve. It is provided in a pipe (hereinafter, referred to as an indicated pressure supply pipe) 21 connecting the main tank 14 and the purge valve 131. The purge control valve 16 opens and closes the indicated pressure supply pipe 21 under the control of the control unit 60 to supply the indicated pressure from the main tank 14 to the purge valve 131 and stop the supply of the indicated pressure. Note that supplying the indicated pressure means supplying the air in the main tank 14 to the purge valve 131. The indicated pressure is supplied to the purge valve 131 when the purge control valve 16 opens the indicated pressure supply pipe 21, and is not supplied to the purge valve 131 when the purge control valve 16 closes the indicated pressure supply pipe 21.

The purge control valve 16 is a directional valve, and when the instruction pressure supply pipe 21 is closed, the purge valve 131 communicates with the atmosphere.

The pressure sensor 17 is attached to the main tank 14. The pressure sensor 17 measures the pressure inside the main tank 14 (hereinafter, referred to as tank pressure), and transmits the measured value D0 to the control unit 60. The pressure sensor 17 may be provided in a pipe connecting the air dryer 13 and the main tank 14. Further, the pressure sensor 17 may be provided in a pipe connecting the air dryer 13 and the main tank 14.

The flow rate sensor 41 is provided in a pipe connecting the compressor 11 and the air dryer 13. The flow rate sensor 41 measures the air flow rate in the pipe connecting the compressor 11 and the air dryer 13, that is, the flow rate of air from the compressor 11 to the air dryer 13, and transmits the measured value D1 to the control unit 60. The flow rate sensor 41 is, for example, an instantaneous flow rate sensor that measures the instantaneous flow rate in the pipe connecting the compressor 11 and the air dryer 13, or a cumulative flow rate sensor that measures the cumulative flow rate in the pipe.

The stop operation detection unit 42 is a switch, and when it detects an operation to stop the operation of the vehicle 100, it transmits a stop operation detection signal S3 notifying that the operation to stop the operation has been detected to the control unit 60. The operation of stopping the operation of the vehicle 100 is, for example, an operation of turning off the ignition key and the engine key.

The instruction operation detection unit 43 includes a purge button provided near the driver's seat of the vehicle 100. When the instruction operation detection unit 43 detects the operation instructing the purge, the instruction operation detection unit 43 transmits the instruction operation detection signal S5 notifying that the operation instructing the purge has been detected to the control unit 60. In the present embodiment, the operation of instructing the purge is to press the purge button. The operation of pressing the purge instruction button and the operation of stopping the operation of the vehicle 100 are both predetermined operations for forcibly executing the purge process.

The control unit 60 controls the entire purge system 1. More specifically, the control unit 60 controls the opening and closing of the purge control valve 16 and the drive control of the motor 12 (that is, based on the various signals S3 and S5 and the measured values D0 and D1 and the like). Compressor drive control).

The control unit 60 has, for example, a CPU (Central Processing Unit), a storage medium such as a ROM (Read Only Memory) in which a control program is stored, and a working memory such as a RAM (Random Access Memory). The operation of the purge system 1 is controlled by executing the control program.

<Control of purge control valve>
The control unit 60 controls the purge control valve 16 in either a normal mode or a purge mode.

In the normal mode, the indicated pressure supply pipe 21 is opened by the purge control valve 16 when the tank pressure reaches the pressure value Pt1, and the indicated pressure supply pipe 21 is opened by the purge control valve 16 when the tank pressure drops to the pressure value Pt2. This is a control mode in which the block is closed by 16. Opening the indicated pressure supply pipe 21 by the purge control valve 16 corresponds to starting the supply of the indicated pressure to the purge valve 131, and closing the indicated pressure supply pipe 21 by the purge control valve 16 corresponds to the purge valve 131. Corresponds to stopping the supply of the indicated pressure to. When the control mode is the normal mode, the control unit 60 controls the purge control valve 16 based on the measured value D0 of the pressure sensor 17.

The pressure value Pt1 is larger than the pressure value Pt2. For example, the pressure value Pt1 is 900 kPa and the pressure value Pt2 is 800 kPa. The pressure value Pt1 is the value of the pressure supplied from the main tank 14 to the purge valve 131, which is the value of the tank pressure when the filling rate of air in the main tank 14 is 100%. The pressure value Pt2 is a pressure value that serves as a guide for executing the operation of supplying air to the main tank 14 by the compressor 11.

The purge mode is a control mode in which the purge control valve 16 keeps opening the indicated pressure supply pipe 21 regardless of the magnitude of the tank pressure. When the control mode is the purge mode, the control unit 60 continues to supply the indicated pressure from the main tank 14 to the purge valve 131 regardless of the tank pressure.

<Compressor control>
When the control unit 60 determines that the measured value D0 of the pressure sensor 17 has reached the pressure value Pt1, the drive of the compressor 11 is stopped. Further, when the control unit 60 determines that the measured value D0 of the pressure sensor 17 has dropped to the pressure value Pt2, the control unit 60 starts driving the compressor 11. In the present embodiment, when the compressor 11 is driven, the control unit 60 is driven so that the supply speed becomes a constant value.

When the control unit 60 determines that the measured value D0 of the pressure sensor 17 has reached the pressure value Pt1, the motor 12 may be rotated at a minute rotational speed instead of stopping the driving of the compressor 11. .. The minute rotation speed is the rotation speed of the motor 12 that can drive the compressor 11 toward the air dryer 13 to the extent that air is not supplied. That is, when the control unit 60 determines that the measured value D0 of the pressure sensor 17 has reached the pressure value Pt1, the air supply to the air dryer 13 by the compressor 11 is stopped, and the measured value D0 of the pressure sensor 17 is the pressure value. If it is determined that the pressure has dropped to Pt2, the air supply to the air dryer 13 by the compressor 11 may be started. In the following description, when the control unit 60 determines that the measured value D0 of the pressure sensor 17 has reached the pressure value Pt1, the drive of the compressor 11 will be stopped.

Hereinafter, the drive control of the compressor 11 by the control unit 60 of the present embodiment will be described with reference to FIG.

FIG. 2 is a diagram illustrating drive start and drive stop of the compressor 11 executed by the purge system 1 according to the embodiment. The upper graph of FIG. 2 shows the time change of the tank pressure. Note that P0 in the upper graph of FIG. 2 indicates atmospheric pressure. The lower graph of FIG. 2 shows the timing at which the drive state (that is, the on state) and the drive stop state (that is, the off state) of the compressor 11 are switched with time. At time T00, the compressor 11 is in the off state, and the purge control valve 16 is in the state of supplying the indicated pressure.

The tank pressure drops due to the use of air in the main tank 14 by each air device of the vehicle 100, and when the tank pressure drops to Pt2 at time T01, the control unit 60 determines the measured value D0 of the pressure sensor 17. It is determined that the pressure has decreased to Pt2. Then, at time T01, the control unit 60 starts driving the compressor 11 and closes the instruction pressure supply pipe 21 by the purge control valve 16. When the indicated pressure supply pipe 21 is closed, the supply of the indicated pressure to the purge valve 131 is stopped.

When the driving of the compressor 11 is started, air is supplied to the main tank 14, and the tank pressure rises.

Then, when the tank pressure reaches Pt1 at time T02, the control unit 60 determines that the measured value D0 of the pressure sensor 17 has reached Pt1. Then, at time T02, the control unit 60 stops the drive of the compressor 11 and opens the instruction pressure supply pipe 21 by the purge control valve 16. When the indicated pressure supply pipe 21 is opened, supply of the indicated pressure to the purge valve 131 is started.

When the drive of the compressor 11 is stopped, the tank pressure drops due to the use of air in the main tank 14 by each air device of the vehicle 100.

When the tank pressure drops to Pt2 at time T03, the control unit 60 determines that the measured value D0 of the pressure sensor 17 has dropped to Pt2. Then, at time T03, the control unit 60 starts driving the compressor 11 and closes the instruction pressure supply pipe 21 by the purge control valve 16. When the indicated pressure supply pipe 21 is closed, the supply of the indicated pressure to the purge valve 131 is stopped.

When the driving of the compressor 11 is started, air is supplied to the main tank 14, and the tank pressure rises.

Then, when the tank pressure reaches Pt1 at time T04, the control unit 60 determines that the measured value D0 of the pressure sensor 17 has reached Pt1. Then, at time T04, the control unit 60 stops the drive of the compressor 11 and opens the instruction pressure supply pipe 21 by the purge control valve 16. When the indicated pressure supply pipe 21 is opened, supply of the indicated pressure to the purge valve 131 is started.

After the time T04, the same operation is repeated.

In this way, the purge control valve 16 supplies the indicated pressure and stops the supply of the indicated pressure according to the change in the tank pressure. When paying attention to the operation of the purge control valve 16, the time from the time when the purge control valve 16 starts supplying the indicated pressure to the time when the purge control valve 16 starts supplying the indicated pressure again, or the time when the purge control valve 16 starts supplying the indicated pressure. One cycle is from the time when the supply of the indicated pressure is stopped to the time when the purge control valve 16 stops supplying the indicated pressure again. For example, in FIG. 2, the time from time T02 to time T04 corresponds to one cycle.

<Switching the control mode of the purge control valve>
FIG. 3 is a flowchart showing a control example of the purge control valve 16 executed by the purge system 1 according to the embodiment. Before the process shown in FIG. 3 is started, the control unit 60 controls the purge control valve 16 in the normal mode.

The control unit 60 determines whether or not the tank pressure is equal to or higher than the first pressure threshold value (step S11). Here, the control unit 60 compares the measured value D0 of the pressure sensor 17 with the first pressure threshold value. The first pressure threshold value may be set in a range of Pt2 or less and larger than the atmospheric pressure. For example, the first pressure threshold value may be 760 kPa, 780 kPa, or 800 kPa. In the following description, the first pressure threshold value will be described as being less than Pt2 and smaller than the pressure value at which the purge control valve 16 stops supplying the indicated pressure. In the following description, the fact that the tank pressure is equal to or higher than the first pressure threshold value may be referred to as the minimum pressure auxiliary condition.

When the tank pressure is smaller than the first pressure threshold value, it can be considered that the amount of air inside the main tank 14 is considerably small. On the other hand, when the tank pressure is equal to or higher than the first pressure threshold value, it can be considered that the amount of air inside the main tank 14 has a relatively large margin even if the supply of the indicated pressure is continued.

When the tank pressure is smaller than the first pressure threshold value (NO in step S11), the control unit 60 maintains the control mode of the purge control valve 16 in the normal mode (step S14), and returns to the process of step S11.

When the tank pressure is equal to or higher than the first pressure threshold value (YES in step S11), the control unit 60 determines whether or not the purge instruction button has been pressed (step S12). The control unit 60 determines that the purge instruction button has been pressed when the instruction operation detection signal S5 is received from the instruction operation detection unit 43, and purges when the instruction operation detection signal S5 is not received from the instruction operation detection unit 43. It is determined that the instruction button is not pressed. In the following description, pressing the purge instruction button of the instruction operation detection unit 43 may be referred to as an intention condition.

When it is determined that the purge instruction button has been pressed (YES in step S12), the control unit 60 starts from the time when the air supply to the air dryer 13 by the compressor 11 is started (hereinafter, referred to as the air supply start time). It is determined whether or not the air supply amount has reached the first flow rate threshold value (step S13).

The air supply start time is the latest time when the control unit 60 receives the measured value D1 whose pressure value is Pt2 or less while the control unit 60 is controlled in the normal mode.

The control unit 60 acquires the measured value D1 by the flow sensor 41 from the air supply start time to the current time, and based on the acquired measured value D1, the period from the air supply start time to the current time (hereinafter, a predetermined period). The cumulative amount of air in the pipe connecting the compressor 11 and the air dryer 13 is calculated. Then, the control unit 60 compares the calculated cumulative air flow rate with the first flow rate threshold value. Here, the cumulative air volume in the predetermined period corresponds to the air supply amount in the predetermined period. Hereinafter, the cumulative air volume of the pipe connecting the compressor 11 and the air dryer 13 is simply referred to as the cumulative air volume.

The first flow rate threshold is determined based on the permissible amount of air passing through the desiccant D. For example, when the allowable amount of air in the desiccant D is 300 L, 330 L, which is 110% of 300 L, may be determined as the first flow rate threshold value, or 240 L, which is 80% of 300 L, may be set as the first flow rate threshold value. It may be decided. The allowable amount of air passing through the desiccant D is determined based on the amount of water and oil that the desiccant D can absorb.

When the amount of air supplied in a predetermined period reaches the first flow rate threshold value, it means that the amount of water or oil that can be additionally absorbed by the desiccant D is relatively small. In the following description, the fact that the air supply amount for a predetermined period is equal to or greater than the first flow rate threshold value is referred to as a supply amount condition (1).

When the air supply amount in the predetermined period has not reached the first flow rate threshold value (NO in step S13), the control unit 60 maintains the control mode of the purge control valve 16 in the normal mode (step S14), and processes in step S11. Return to.

When the air supply amount in the predetermined period reaches the first flow rate threshold value (YES in step S13), the control unit 60 determines whether or not the time when the tank pressure does not reach Pt1 is less than the reference pressure time TS1 (YES in step S13). Step S15).

The control unit 60 measures the time from the time when the tank pressure reaches Pt1 most recently, and compares the measured time with the reference pressure time TS1. Here, the longer the measured time, the longer the period during which the filling rate of the main tank 14 does not reach close to 100%, and the period during which the indicated pressure is not supplied to the purge valve 131 by the purge control valve 16. It means that it may be prolonged. The reference pressure time TS1 is a value set to prevent the period in which the filling rate of the main tank 14 does not reach close to 100% from being prolonged, and is, for example, 10 minutes.

When the measurement time in step S15 is equal to or longer than the reference pressure time TS1, for example, although the tank pressure exceeds Pt2, the tank pressure remains flat due to a large amount of air used by the air equipment. Therefore, it is assumed that it takes time for the tank pressure to reach Pt1. In the following description, the time when the tank pressure does not reach Pt1, that is, the time when the tank pressure is less than Pt1 is less than the reference pressure time TS1, is referred to as the air amount auxiliary condition (1).

When the time when the tank pressure does not reach Pt1 is equal to or longer than the reference pressure time TS1 (NO in step S15), the control unit 60 maintains the control mode of the purge control valve 16 in the normal mode (step S14), and in step S11. Return to processing.

When the time when the tank pressure does not reach Pt1 is less than the reference pressure time TS1 (YES in step S15), the control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode (step S16).

As a result, the indicated pressure supply pipe 21 is opened, so that the indicated pressure is always supplied to the purge valve 131. As soon as the control mode of the purge control valve 16 is switched to the purge mode, the indicated pressure is supplied from the main tank 14 to the purge valve 131. Therefore, in the air dryer 13, the purge process is performed in response to the indicated pressure supplied from the main tank 14. By supplying the indicated pressure to the purge valve 131, the amount of air in the main tank 14 gradually decreases.

Next, the control unit 60 determines whether or not the tank pressure is smaller than the second pressure threshold value (step S17). The control unit 60 compares the measured value D0 of the pressure sensor 17 with the second pressure threshold value. The second pressure threshold value may be set in a range of Pt2 or less and larger than the atmospheric pressure. The second pressure threshold is, for example, 750 kPa. The second pressure threshold value may be a value equal to or less than the first pressure threshold value. In the following description, the fact that the tank pressure is smaller than the second pressure threshold value may be referred to as the pressure release condition (1).

When the tank pressure is smaller than the second pressure threshold value (YES in step S17), the control unit 60 switches the control mode of the purge control valve 16 from the purge mode to the normal mode (step S18). That is, the control unit 60 controls the opening and closing of the purge control valve 16 in the control mode in which the supply of the instruction pressure to the purge valve 131 and the supply of the instruction pressure are stopped according to the tank pressure.

At the timing when the control mode of the purge control valve 16 is switched from the purge mode to the normal mode, the tank pressure is less than Pt2 at the maximum. Therefore, when the control unit 60 switches the control mode of the purge control valve 16 from the purge mode to the normal mode, the indicator pressure supply pipe 21 is blocked by the purge control valve 16. Therefore, by switching from the purge mode to the normal mode, the supply of the indicated pressure from the main tank 14 to the purge valve 131 is stopped. Therefore, the purge process in the air dryer 13 is stopped.

When the tank pressure is equal to or higher than the second pressure threshold value (NO in step S17), it is determined whether or not the time when the tank pressure does not reach Pt1 is equal to or longer than the reference pressure time TS3 (step S19). The control unit 60 measures the time from the time when the tank pressure reaches Pt1 most recently, and compares the measured time with the reference pressure time TS3. The reference pressure time TS3 is a value set to prevent the period in which the filling rate of the main tank 14 does not reach close to 100% from being prolonged, and is, for example, 15 minutes. The reference pressure time TS3 may be at least the reference pressure threshold value TS1 or higher. In the following description, the time from the time when the tank pressure reaches Pt1 most recently is the reference pressure time TS3 or more, which is referred to as the air amount release condition (1).

When the time when the tank pressure does not reach Pt1 is less than the reference pressure time TS3 (NO in step S19), the control unit 60 executes the process of step S17. When the time when the tank pressure does not reach Pt1 is equal to or longer than the reference pressure time TS3 (YES in step S19), the control unit 60 executes the process of step S18.

When it is determined that the purge instruction button is not pressed (NO in step S12), the control unit 60 determines whether or not the latest purge time is less than the reference time (step S20). The purge time is the time from the time when the tank pressure reaches Pt1 to immediately before the time when the tank pressure drops to Pt2 while the purge control valve 16 is controlled in the normal mode. In other words, it is the time from the time when the control unit 60 receives the measured value D0 whose tank pressure is Pt1 or more to immediately before the time when the measured value D0 whose tank pressure is Pt2 or less is received. For example, the purge time is the time from time T02 to immediately before time T03 in FIG. The purge time is measured by the control unit 60. In the following description, the fact that the latest purge time is less than the reference time is referred to as a purge time condition.

The reference time is determined based on a guideline for the execution time of the purge process per cycle. For example, when the guideline of the execution time of the purge process is 60 seconds, the reference time may be determined to be 60 seconds or 30 seconds, which is a value of 50% of the guideline.

When the latest purging time is equal to or longer than the reference time, it is assumed that the water and oil in the desiccant D have been sufficiently removed. On the other hand, when the purge time is less than the reference time, the indicated pressure supply pipe 21 is blocked by the purge control valve 16 and the purge process is completed in a situation where the water and oil content of the desiccant D is not sufficiently removed. is assumed.

When the purge time is equal to or longer than the reference time (NO in step S20), the control unit 60 executes the process of step S14.

When the purge time is less than the reference time (YES in step S20), the control unit 60 determines whether or not the air supply amount in the predetermined period described above has reached the second flow rate threshold value (step S21). The control unit 60 acquires the measured value D1 by the flow rate sensor 41 in the predetermined period, and calculates the cumulative air flow rate of the air in the pipe connecting the compressor 11 and the air dryer 13 in the predetermined period based on the acquired measured value D1. Then, the control unit 60 compares the calculated cumulative air flow rate with the second flow rate threshold value.

The second flow rate threshold is determined based on the permissible amount of air passing through the desiccant D. For example, when the allowable amount of air in the desiccant D is 300 L, 450 L, which is 150% of 300 L, may be determined as the second flow rate threshold value, or 300 L may be determined as the second flow rate threshold value.

When the amount of air supplied in a predetermined period reaches the second flow rate threshold value, it means that the amount of water or oil that can be additionally absorbed by the desiccant D is very small. In the following description, the fact that the air supply amount for a predetermined period is equal to or greater than the second flow rate threshold value is referred to as a supply amount condition (2). The second flow rate threshold value may be the same value as the first flow rate threshold value. In this case, the supply amount conditions (1) and (2) are the same as each other.

When the air supply amount for a predetermined period has not reached the second flow rate threshold value (NO in step S21), the control unit 60 executes the process of step S14.

When the air supply amount in the predetermined period reaches the second flow rate threshold value (YES in step S21), the control unit 60 determines whether or not the time when the tank pressure does not reach Pt1 is less than the reference pressure time TS2 (YES in step S21). Step S22). The reference pressure time TS2 is a value set to prevent the period in which the filling rate of the main tank 14 does not reach close to 100% from being prolonged, and is, for example, 5 minutes. The reference pressure time TS2 is shorter than the reference pressure time TS1. Therefore, when the purge instruction button is pressed, the control mode of the purge control valve 16 is more likely to be switched to the purge mode than when the purge instruction button is not pressed. Therefore, since the indicated pressure can be easily supplied to the purge valve 131, the purge process can be easily performed by the air dryer 13. The reference pressure time TS2 may be the same as the reference pressure time TS1. In the following description, the time when the tank pressure does not reach Pt1, that is, the time when the tank pressure is less than Pt1 is less than the reference pressure time TS2 is referred to as the air amount auxiliary condition (2). When the reference pressure time TS2 is the same time as the reference pressure time TS1, the air amount auxiliary condition (2) is the same as the air amount auxiliary condition (1).

When the time when the tank pressure does not reach Pt1 is equal to or longer than the reference pressure time TS2 (NO in step S22), the control unit 60 executes the process of step S14. When the time when the tank pressure does not reach Pt1 is less than the reference pressure time TS2 (YES in step S22), the control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode (step S23).

As soon as the control mode of the purge control valve 16 is switched to the purge mode, the indicated pressure is supplied from the main tank 14 to the purge valve 131. Therefore, in the air dryer 13, the purge process is performed in response to the indicated pressure supplied from the main tank 14. By supplying the indicated pressure to the purge valve 131, the amount of air in the main tank 14 gradually decreases.

Next, the control unit 60 determines whether or not the tank pressure is smaller than the third pressure threshold value (step S24). The control unit 60 compares the measured value D0 of the pressure sensor 17 with the third pressure threshold value. The third pressure threshold value may be set in a range of Pt2 or less and larger than the atmospheric pressure. The third pressure threshold value is larger than the second pressure threshold value and is the same value as the first pressure threshold value. In the following description, the fact that the tank pressure is smaller than the second pressure threshold value may be referred to as the pressure release condition (2). The third pressure threshold value may be smaller than the first pressure threshold value. Further, the third pressure threshold value may be the same value as the second pressure threshold value. When the third pressure threshold value is the same value as the second pressure threshold value, the pressure release condition (2) and the pressure release condition (1) are the same as each other.

When the tank pressure is smaller than the third pressure threshold value (YES in step S24), the control unit 60 switches the control mode of the purge control valve 16 from the purge mode to the normal mode (step S18). That is, the control unit 60 controls the opening and closing of the purge control valve 16 in the control mode in which the supply of the instruction pressure to the purge valve 131 and the supply of the instruction pressure are stopped according to the tank pressure.

Therefore, the supply of the indicated pressure from the main tank 14 to the purge valve 131 is stopped. Therefore, the purge process in the air dryer 13 is stopped.

When the tank pressure is equal to or higher than the third pressure threshold value (NO in step S24), it is determined whether or not the time when the tank pressure does not reach Pt1 is equal to or longer than the reference pressure time TS4 (step S25). The control unit 60 measures the time from the time when the tank pressure reaches Pt1 most recently, and compares the measured time with the reference pressure time TS4. The reference pressure time TS4 is a value set to prevent the period in which the filling rate of the main tank 14 does not reach close to 100% from being prolonged, and is, for example, 12 minutes. The reference pressure time TS4 is shorter than the reference pressure time TS3. Therefore, when the purge instruction button is pressed, it is more difficult to switch the control mode to the normal mode than when the purge instruction button is not pressed, so that the instruction pressure is continuously supplied for a longer time. That is, when the purge instruction button is pressed, the purge process by the air dryer 13 can be easily continued. The reference pressure time TS4 may be the same as the reference pressure time TS3. The reference pressure time TS4 may be a value equal to or greater than the reference pressure time TS3. In the following description, the time from the time when the tank pressure reaches Pt1 most recently is the reference pressure time TS4 or more, which is referred to as the air amount release condition (2).

When the time when the tank pressure does not reach Pt1 is less than the reference pressure time TS4 (NO in step S25), the control unit 60 moves to the process of step S24. When the time when the tank pressure does not reach Pt1 is equal to or longer than the reference pressure time TS4 (YES in step S25), the control unit 60 executes the process of step S18. After that, the control unit 60 proceeds to step S11.

<Notification>
The control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode (steps S15 and S23), and notifies the occupant of the vehicle 100 that the forced purge period is in progress through the output unit (not shown). .. At this time, the control unit 60 may announce through the output unit that the forced purge period is in effect, may display a screen for displaying characters indicating that the forced purge period is in effect, or display the announcement and the screen display. It may be notified in combination.

The forced purge period is a period in which the purge control valve 16 is controlled in the purge mode. In other words, the indicated pressure supply pipe 21 is open and the indicated pressure is transferred from the main tank 14 to the purge valve 131. It is the period of supply.

Similarly, the control unit 60 switches the control mode of the purge control valve 16 from the purge mode to the normal mode (step S18), and notifies the occupant of the vehicle 100 that the forced purge period has been canceled through the output unit. At this time, the control unit 60 may announce through the output unit that the forced purge period has been released, or may display a screen for displaying characters indicating that the forced purge period has been released. Notification may be performed in combination with screen display.

Note that the forced purge period is released means that the forced purge period is changed to the normal purge period in which the purge control valve 16 is controlled in the normal mode. The normal purge period is also a period in which the indicated pressure is supplied from the main tank 14 to the purge valve 131 according to the magnitude of the tank pressure.

Further, the control unit 60 may notify the forced purge period through the output unit as shown below.
(1) When the purge instruction button is not pressed (off state), the information regarding the forced purge period is not shown through the output unit.
(2) When the purge instruction button is pressed (on state) and the purge control valve 16 is controlled in the purge mode, the first color (for example, orange) indicates that the forced purge period is in effect. Display the screen indicated by in the output section.
(3) When the purge instruction button is pressed (on state) and the purge control valve 16 is controlled in the normal mode, the fact that the forced purge period cannot be entered is different from the first color. A screen shown in two colors (for example, green) is displayed on the output unit. When the control unit 60 gives the notification shown in (3) through the output unit, the occupant of the vehicle 100 is in a situation where the purge system 1 does not shift to the forced purge period even though the purge instruction button is pressed. You can know that there is.

<Other controls>
In the control shown by the flowchart of FIG. 3, the intention condition, the supply amount condition (1), the supply amount condition (2), the purge time condition, the minimum pressure auxiliary condition, the air amount auxiliary condition (1), and the air amount auxiliary condition ( 2) When only one condition is satisfied, the control unit 60 does not switch the control mode of the purge control valve 16 from the normal mode to the purge mode.

However, the control unit 60 controls the purge control valve on the condition that only one of the supply amount condition (1), the supply amount condition (2), and the purge time condition is satisfied. The 16 control modes can be switched from the normal mode to the purge mode.

Further, the control unit 60 can determine whether or not the supply amount condition (1) is satisfied by a method other than calculating the air supply amount based on the measured value D1 by the flow rate sensor 41.

(Supply amount condition (1): Time measurement)
When the first predetermined time elapses from the air supply start time, the control unit 60 can determine that the supply amount condition (1) is satisfied. The control unit 60 measures the time from the air supply start time to the current time, and compares the measured time with the first predetermined time.

The first predetermined time is determined based on the allowable amount of air passing through the desiccant D and the air supply speed of the compressor 11. For example, when the allowable amount of air in the desiccant D is 300 L and the air supply speed of the compressor 11 is 150 L / min, 1 minute and 36 seconds may be determined as the first predetermined time, and 2 minutes and 12 seconds may be determined. It may be determined at the first predetermined time. Note that 1 minute and 36 seconds is the time required for the air of 240 L from the compressor 11 to be supplied to the air dryer 13. Further, 2 minutes and 12 seconds is the time required for the air of 330 L from the compressor 11 to be supplied to the air dryer 13.

When the first predetermined time has elapsed from the air supply start time, it means that the amount of water or oil that can be additionally absorbed by the desiccant D is relatively small.

That is, by determining the first predetermined time so that the air supply amount based on the first predetermined time matches the first flow rate threshold value, the air supply amount from the compressor 11 to the air dryer 13 in the above-mentioned predetermined period becomes the first. It is possible to determine whether or not one flow rate threshold has been reached, that is, whether or not the supply amount condition (1) has been satisfied.

(Supply amount condition (1): Time measurement and air supply speed)
The control unit 60 measures the time elapsed from the air supply start time, and the measurement is performed based on the measured time and the air supply speed of the compressor 11 when the compressor 11 is supplying air to the air dryer 13. Calculate the cumulative air flow (that is, the air supply) over the time. Then, when the calculated cumulative air flow rate reaches the first flow rate threshold value, the control unit 60 can determine that the supply amount condition (1) is satisfied. In this way, by calculating the air supply amount based on the elapsed time from the air supply start time and the air supply speed of the compressor 11, the control unit 60 supplies air to the air dryer 13 by the compressor 11. Even if the air supply speed of the compressor 11 changes during that time, it is possible to accurately determine whether or not the supply amount condition (1) is satisfied. For example, the air supply start time is T11, the air supply speed from time T11 to time T12 one minute later is 100 L / min, and the air supply speed of the compressor 11 from time T12 to the current time one minute later is 150 L / min. If it is minutes, the control unit 60 can calculate the air supply amount from the air supply time to the current time as 250L (100L + 150L). The air supply speed depends on the rotation speed of the motor 12 that drives the compressor 11.

Similarly, the control unit 60 can determine whether or not the supply amount condition (2) is satisfied by a method other than calculating the air supply amount based on the measured value D1 by the flow rate sensor 41.

(Supply amount condition (2): Time measurement)
When the second predetermined time elapses from the air supply start time, the control unit 60 can determine that the supply amount condition (2) is satisfied. The control unit 60 measures the time from the air supply start time to the current time, and compares the measured time with the second predetermined time.

The second predetermined time is determined based on the allowable amount of air passing through the desiccant D and the air supply speed of the compressor 11. For example, when the allowable amount of air in the desiccant D is 300 L and the air supply speed of the compressor 11 is 150 L / min, 2 minutes may be determined as the second predetermined time, and 3 minutes may be determined as the second predetermined time. May be decided. 2 minutes is the time required for 300 L of air from the compressor 11 to be supplied to the air dryer 13. Further, 3 minutes is the time required for the air of 450 L from the compressor 11 to be supplied to the air dryer 13.

When the second predetermined time has elapsed from the air supply start time, it means that the amount of water or oil that can be additionally absorbed by the desiccant D is very small.

That is, by determining the second predetermined time so that the air supply amount based on the second predetermined time matches the second flow rate threshold value, the air supply amount from the compressor 11 to the air dryer 13 in the above-mentioned predetermined period becomes the second. 2 It is possible to determine whether or not the flow rate threshold has been reached, that is, whether or not the supply amount condition (2) has been satisfied.

(Supply amount condition (2): Time measurement and air supply speed)
The control unit 60 measures the time elapsed from the air supply start time, and the measurement is performed based on the measured time and the air supply speed of the compressor 11 when the compressor 11 is supplying air to the air dryer 13. Calculate the cumulative air flow (that is, the air supply) over the time. Then, when the calculated cumulative air flow rate reaches the second flow rate threshold value, the control unit 60 can determine that the supply amount condition (2) is satisfied.

As described above, the purge system 1 of the present embodiment satisfies only one of the supply amount condition (1), the supply amount condition (2), and the purge time condition. By controlling the purge control valve 16 in the purge mode in which the indicated pressure supply pipe 21 is opened regardless of the tank pressure, the indicated pressure can be supplied to the purge valve 131. As a result, the purge system 1 of the present embodiment can supply the indicated pressure to the purge valve 131 and cause the air dryer 13 to execute the purge process regardless of the tank pressure. As a result, the frequency of the purging treatment (that is, the regeneration treatment of the desiccant D) in the air dryer 13 can be increased, so that the load on the desiccant D of the air dryer 13 can be reduced. As a result, the desiccant D is less likely to deteriorate, and the life of the air dryer 13 and the desiccant D can be extended. By reducing the load on the desiccant D, poor moisture absorption of the desiccant D is less likely to occur. As a result, it is possible to prevent the piping connecting the air dryer 13 and the main tank 14 and the piping connecting the main tank 14 and each air device from freezing and blocking the piping. Further, it is possible to prevent rust on the piping and the main tank 14, and malfunction of the purge control valve 16 and the like.

Since the purge system 1 of the present embodiment does not have a governor, the number of parts of the purge system 1 can be reduced, so that the purge system 1 can be made smaller than the case where the governor is provided.

The purge system 1 of the present embodiment is provided with a pressure sensor 17 and a purge control valve 16 instead of being provided with a governor, and controls the purge control valve 16 in the normal mode to supply the indicated pressure to the purge valve 131. Can be prevented from becoming excessively large, and the air in the main tank 14 can be effectively utilized.

When any of the supply amount condition (1) and the supply amount condition (2) is satisfied, the control unit 60 can switch the control mode of the purge control valve 16 from the normal mode to the purge mode. .. Therefore, when the amount of air supplied to the main tank 14 by the compressor 11 during a predetermined period is large, the control mode is switched to the purge mode to open the indicated pressure supply pipe 21 to the purge control valve 16. As a result, the purging process is executed in consideration of the amount of water and fat that can be absorbed by the desiccant D of the air dryer 13 without waiting until the air filling rate of the main tank 14 becomes close to 100%. Therefore, it is possible to reduce the load on the desiccant D due to the fact that the purging treatment is not performed for a long period of time, and to make the desiccant D less likely to deteriorate. As a result, the life of the air dryer 13 and the desiccant D can be extended.

The compressor 11 and the air dryer 13 are used to determine whether or not the supply amount conditions (1) and (2) are satisfied by a method of calculating the air supply amount based on the measured value D1 of the flow rate sensor 41. Since the air flow rate of the pipe connecting the above is directly measured, a more accurate air supply amount can be calculated.

By using a method of determining whether or not the supply amount conditions (1) and (2) are satisfied based on the elapsed time from the air supply start time, the purge system 1 does not include the flow rate sensor 41. It is possible to determine whether the amount of air supplied to the air dryer 13 is large or small.

By using a method of determining whether or not the supply amount conditions (1) and (2) are satisfied based on the elapsed time from the air supply start time and the air supply speed of the compressor 11, the purge system 1 can be used. Without providing the flow rate sensor 41, it is possible not only to determine whether the amount of air supplied to the air dryer 13 is large or small, but also to accurately calculate the amount of air supplied even when the supply speed of the compressor 11 changes. can.

When the purge time condition is satisfied, the control unit 60 can switch the control mode of the purge control valve 16 from the normal mode to the purge mode. As a result, it is possible to detect that the desiccant D has not been sufficiently regenerated and to execute the purging process.

The control unit 60 not only satisfies any of the supply amount condition (1), the supply amount condition (2), and the purge time condition, but also satisfies the minimum pressure auxiliary condition, and the purge control valve. The 16 control modes can be switched from the normal mode to the purge mode. As a result, for example, when the tank pressure value is maintained below the first threshold pressure immediately after the vehicle 100 is started, the supply amount condition (1), the supply amount condition (2), and the purge Even if any of the time conditions is satisfied, the control unit 60 keeps the control mode of the purge control valve 16 as the normal mode. Therefore, when the tank pressure is low, the indicated pressure supply pipe 21 remains blocked by the purge control valve 16, and the air in the main tank 14 is not used as the indicated pressure. Therefore, it becomes easy to store air in the main tank 14.

The control unit 60 not only satisfies any of the supply amount condition (1), the supply amount condition (2), and the purge time condition, but also includes the air amount auxiliary condition (1) or the air amount auxiliary condition (2). The control mode of the purge control valve 16 can be switched from the normal mode to the purge mode on condition that the above conditions are satisfied. As a result, when the tank pressure is Pt2 or higher but it takes a long time to rise to Pt1, the instruction pressure supply pipe 21 is left closed and the air in the main tank 14 is used as the instruction pressure. Instead, it is possible to give priority to storing air in the main tank 14.

When the pressure release condition (1) or the pressure release condition (2) is satisfied, the control unit 60 switches the control mode to a normal mode in which the instruction pressure supply pipe 21 is opened and closed according to the tank pressure. As a result, the indicated pressure is no longer supplied to the purge valve 131, and the purge process is stopped. Therefore, the amount of air in the main tank 14 can be secured so that the air device can always use the air in the main tank 14.

When the air amount release condition (1) or (2) is satisfied, the control unit 60 switches the control mode of the purge control valve 16 from the purge mode to the normal mode. As a result, the air in the main tank 14 is not used as the indicated pressure. Therefore, when the tank pressure does not rise to Pt1 but drops, such as when the amount of air used is large, the filling rate of the main tank 14 increases. It is possible to shorten the period when it does not become close to 100%.

<Modification example 1>
In the above-described embodiment, when the supply amount condition (1) is satisfied in addition to the intention condition, the control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode. The purge system 1 of the modification 1 switches the control mode of the purge control valve 16 from the normal mode to the purge mode when the intention condition is satisfied regardless of the supply amount condition (1). Hereinafter, the purge system 1 according to the modified example 1 will be mainly described in that it differs from the above-described embodiment.

FIG. 4 is a flowchart showing a control example of the purge control valve 16 executed by the purge system 1 according to the modification 1. The steps showing the same control as in FIG. 3 are assigned the same step numbers. Before the process shown in FIG. 4 is started, it is assumed that the purge control valve 16 is controlled in the normal mode.

First, the control unit 60 determines whether or not the tank pressure is equal to or higher than the first pressure threshold value (step S11). When the tank pressure is smaller than the first pressure threshold value (NO in step S11), the purge control valve 16 is controlled so as to maintain the control mode of the purge control valve 16 in the normal mode (step S14), and the process in step S11 is performed. return.

When the tank pressure is equal to or higher than the first pressure threshold value (YES in step S11), the control unit 60 determines whether or not the purge instruction button has been pressed (step S31). If the purge instruction button is not pressed (NO in step S31), the control unit 60 executes the process of step S14 and returns to step S11.

When the purge instruction button is pressed (YES in step S31), the control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode (step S16). That is, when the purge instruction button is pressed, the control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode regardless of whether the supply amount condition (1) is satisfied.

After that, the control unit 60 determines whether or not the tank pressure is smaller than the first pressure threshold value (step S32). When the tank pressure is equal to or higher than the first pressure threshold value (NO in step S32), the control unit 60 repeats the process of step S32 until the tank pressure becomes smaller than the first pressure threshold value. When the tank pressure is smaller than the first pressure threshold value (YES in step S32), the control unit 60 switches the control mode of the purge control valve 16 from the normal mode to the purge mode (step S18). Then, the process returns to step S11.

In steps S11 and S32, the tank pressure may be compared with the second pressure threshold or the third pressure threshold.

According to the first modification, when the intention condition is satisfied, the control unit 60 switches the control mode of the purge control valve 16 to the purge mode regardless of whether the supply amount condition (1) is satisfied. .. Therefore, the purging process can be executed by giving priority to the intention of the occupant of the vehicle 100.

When the control unit 60 satisfies both the intention condition and the minimum pressure auxiliary condition, the control unit 60 switches the control mode of the purge control valve 16 to the purge mode, so that the occupant of the vehicle 100 desires to execute the purge process. Even so, when the tank pressure is small, the indicated pressure is not supplied, so that the amount of air in the main tank 14 can be secured.

<Modification 2>
The purge control valve 16 may be composed of a plurality of on-off valves as shown in FIGS. 5A and 5B. FIG. 5A is a diagram showing a purge control valve 16 included in the purge system 1 according to the second modification, showing the purge system 1 in a state where the instruction pressure supply pipe 21 is open. FIG. 5B is a diagram showing a purge control valve 16 included in the purge system 1 according to the second modification, showing the purge system 1 in a state where the instruction pressure supply pipe 21 is closed.

The purge control valve 16 is provided in a first valve 161 provided in the indicated pressure supply pipe 21 and a second valve provided in a pipe (hereinafter referred to as an air opening pipe) 22 for communicating the purge valve with the atmosphere. It may be composed of 162. When the second valve 162 opens the air opening pipe 22, the purge valve 131 communicates with the atmosphere. The first valve 161 and the second valve 162 are valves for switching between opening and closing of the pipe.

The control unit 60 opens the instruction pressure supply pipe 21 by the first valve 161 at the timing of opening the instruction pressure supply pipe 21, and closes the atmosphere release pipe 22 by the second valve 162 (see FIG. 5A). .. Further, the control unit 60 closes the instruction pressure supply pipe 21 by the first valve 161 at the timing of closing the instruction pressure supply pipe 21, and opens the atmosphere release pipe 22 by the second valve 162 (see FIG. 5B). ..

<Modification example 3>
Hereinafter, the purge system 1 according to the third modification will be described mainly different from the above-described embodiment. FIG. 6 is a diagram showing a main configuration of the purge system 1 according to the modified example 3. In the third modification, the purge control valve 16 is arranged inside the air dryer 13. Further, the instruction pressure supply pipe 21 connects the pipe that supplies the air of the air dryer 13 to the main tank 14 (hereinafter, referred to as a tank upstream pipe) and the purge valve 131 via the purge control valve 16. That is, in the modification 3, the indicated pressure is supplied to the purge valve 131 via the tank upstream pipe and the indicated pressure supply pipe 21.

The control content of the purge control valve 16 is the same as that of the above-described embodiment, and according to the purge system 1 according to the third modification, the same effect as that of the embodiment can be obtained. Further, the purge control valve 16 of the modification 3 may also be composed of a plurality of on-off valves as shown in the modification 2.

<Other modifications>
The control unit 60 sets the control unit 60 on the condition that only the intention condition is satisfied regardless of whether or not the minimum pressure auxiliary condition, the air amount auxiliary condition (1) and the air amount auxiliary condition (2) are satisfied. The control mode of the purge control valve 16 may be switched from the normal mode to the purge mode. As a result, the occupant of the vehicle 100 can execute the purge process at an arbitrary timing. Therefore, it is possible to execute the purge treatment at a high frequency to reduce the load on the desiccant D and prevent the desiccant D from deteriorating. As a result, the life of the air dryer 13 and the desiccant D can be extended.

The control unit 60 may switch the control mode of the purge control valve 16 from the normal mode to the purge mode when the operation of the vehicle 100 is stopped (stop condition), that is, when the vehicle 100 is turned off. When the control unit 60 receives the stop operation detection signal S3, the control unit 60 determines that the stop condition is satisfied. As a result, when the air equipment of the vehicle 100 is in a state of not using air for a certain period of time, such as when the vehicle 100 is parked, the purge process can be executed each time. Therefore, the frequency of purging can be further increased.

The purge system 1 further includes a start operation detection unit that transmits a start operation detection signal to the control unit 60 to notify that the start of the operation of the vehicle 100 has been detected when the operation to start the operation of the vehicle 100 is detected. You may be. Then, when the control unit 60 receives the start operation detection signal, the control mode of the purge control valve 16 may be switched from the purge mode to the normal mode. The operation of starting the operation of the vehicle 100 is, for example, an operation of turning on the ignition key or the engine key.

As a result, even if the operation of the vehicle 100 is turned off while the instruction pressure supply pipe 21 is opened by the purge control valve 16, if the operation of the vehicle 100 starts and the pressure becomes Pt2 or less, the instruction pressure is supplied. The pipe 21 can be returned to the state of being blocked by the purge control valve 16. Therefore, immediately after the operation of the vehicle 100 is started, it becomes easy to fill the main tank 14 with air.

Further, the control unit 60 may count the number of times the indicated pressure supply pipe 21 is opened by the purge control valve 16 (hereinafter, referred to as the number of times of opening) after the latest time when the tank pressure reaches Pt1. .. The control unit 60 then continues counting until the time when the tank pressure reaches Pt1. The number of times of opening corresponds to the number of times that the control mode is switched from the normal mode to the purge mode after the latest time when the tank pressure reaches Pt1.

When the number of times of opening is less than the threshold number (number of times auxiliary condition) and at least one of the intention condition, the supply amount condition (1), the supply amount condition (2), the purge condition, and the stop condition is satisfied. The control unit 60 may switch the control mode of the purge control valve 16 from the normal mode to the purge mode. The threshold number is a value set in order to prevent the period in which the filling rate of the main tank 14 does not reach close to 100% from being prolonged, and is, for example, three times.

When the tank pressure is Pt2 or higher but it takes a long time to rise to Pt1 by imposing the number-of-times auxiliary condition on the condition for switching the control mode of the purge control valve 16 to the purge mode, Since the indicated pressure supply pipe 21 remains closed, it is possible to give priority to storing air in the main tank 14 without using the air in the main tank 14 as the indicated pressure.

The control unit 60 imposes a number-of-times auxiliary condition, a minimum pressure auxiliary condition, an air amount auxiliary condition (1), and an air amount auxiliary condition (2) as conditions for switching the control mode of the purge control valve 16 to the purge mode. In the case, at least one of them may be set, and if two or more are imposed, any combination may be imposed.

Further, in the control unit 60, when the purge control valve 16 is controlled in the purge mode, the counted number of times of opening is equal to or greater than the threshold number (number release assisting condition), and the pressure release condition (1) and When any of the pressure release condition (2) is satisfied, the control unit 60 may switch the control mode of the purge control valve 16 to the normal mode.

Since the condition for switching the control mode of the purge control valve 16 to the normal mode is imposed with the condition for assisting the release of the number of times, it takes a long time for the tank pressure to rise to Pt1 such as when the amount of air used is large. In this case, the supply of the indicated pressure to the purge valve 131 can be stopped to shorten the period in which the filling rate of the main tank 14 does not approach 100%.

In the number-of-times auxiliary condition, the threshold number of times when the intention condition is not satisfied may be smaller than the threshold number of times when the intention condition is satisfied. In addition, the number of times determined when the intention condition is satisfied and the mode is switched to the purge mode is more than the number of times determined when the intention condition is not satisfied and the mode is switched to the purge mode, rather than the threshold number of the release auxiliary condition. The threshold number of cancellation assistance conditions may be small.

When the compressor 11 supplies air toward the air dryer 13, the control unit 60 may change the supply speed of the compressor 11. That is, the control unit 60 may change the rotation speed of the motor 12.

Further, in the above-described embodiment and each modification, a flow velocity sensor may be provided instead of the flow rate sensor 41. In this case, the flow velocity sensor measures the flow velocity of the air passing through the pipe of the flow velocity sensor and transmits the measured value to the control unit 60. The control unit 60 determines the measured value and the cross-sectional area of the pipe of the flow velocity sensor. Based on this, the cumulative air flow rate (that is, the air supply amount) can be calculated.

Further, the control unit 60 may switch the control mode of the purge control valve 16 from the normal mode to the purge mode when the humidity inside the air dryer 13 is equal to or higher than a predetermined humidity.

The purge system 1 of the present disclosure may have a configuration in which air is sent not only to the purge valve 131 but also to the compressor 11 by the operation of the purge control valve 16. Further, the compressor 11 does not necessarily have to be an electric compressor, and may be a compressor that operates in conjunction with the operation of a drive source such as an engine.

In the above-described embodiment, the vehicle 100 has been described as a large vehicle, but any vehicle may be used as long as it is equipped with a device that uses air. The vehicle 100 may be, for example, an electric vehicle. Further, since the purge system 1 does not necessarily have to stop the air supply to the air dryer 13 by the compressor 11, the vehicle 100 may be an engine vehicle.

Further, the purge system 1 described above may be mounted not only on the vehicle 100 but also on any device that uses air.

The above-described embodiments are merely examples of the embodiment of the present disclosure, and the technical scope of the present disclosure should not be construed in a limited manner by these. That is, the present disclosure can be carried out in various forms without departing from its gist or its main features.

The present disclosure may be suitably applied to a purge system that regenerates a desiccant in an air dryer by a purge process.

1 Purge system 11 Compressor 12 Motor 13 Air dryer 131 Purge valve 14 Main tank 16 Purge control valve 161 First valve 162 Second valve 17 Pressure sensor 21 Instructed pressure supply piping 22 Air release piping 41 Flow sensor 42 Stop operation detector 43 Instructed Operation detection unit 60 Control unit 100 Vehicle S3 Stop operation detection signal S5 Instructed operation detection signal D0, D1 Measured value

Claims (11)

With the main tank
A compressor that discharges air and
An air dryer that has a purge valve and supplies the air discharged from the compressor to the main tank, and
When the tank pressure, which is the pressure in the main tank, reaches the first pressure value, the supply of the indicated pressure from the main tank to the purge valve is started, and the tank pressure is smaller than the first pressure value. A control mode of either a first control mode in which the supply of the indicated pressure is stopped when the pressure drops to the second pressure value and a second control mode in which the indicated pressure is supplied regardless of the tank pressure. Purge control valve controlled by
The purge control valve is controlled, a predetermined operation is detected, it is determined that the amount of air supplied to the air dryer by the compressor in a predetermined period is equal to or higher than the first threshold value, and the purge control When at least one of the time from the time when the valve starts supplying the indicated pressure to the time when the purge control valve stops supplying the indicated pressure is less than the reference time is satisfied, the purge control valve is satisfied. A control unit that switches the control mode of the above from the first control mode to the second control mode, and
Purge system with. The control unit stops the air supply to the air dryer by the compressor when the tank pressure reaches the first pressure value, and the air when the tank pressure drops to the second pressure value. Start supply,
The purge system according to claim 1. The purge control valve has a first valve provided in a pipe connecting the main tank and the purge valve, and a second valve that allows the purge valve to communicate with the atmosphere by opening.
The control unit closes the first valve at the timing when the supply of the instruction pressure is stopped, opens the second valve, and starts the supply of the instruction pressure at the timing when the control unit starts supplying the instruction pressure. The first valve is opened and the second valve is closed.
The purge system according to claim 1 or 2. A flow rate sensor that measures the flow rate of air from the compressor to the air dryer and transmits the measured value of the flow rate to the control unit is further provided.
When the amount of air supplied from the time when the air supply to the air dryer by the compressor is started reaches the first threshold value, the control unit changes the control mode of the purge control valve from the first control mode. The purge system according to any one of claims 1 to 3, which switches to the second control mode. When a predetermined time has elapsed from the time when the air supply to the air dryer by the compressor is started, the control unit switches the control mode of the purge control valve from the first control mode to the second control mode. The purge system according to any one of claims 1 to 3. The control unit starts from the time when the indicated pressure is no longer supplied to the purge valve based on the time elapsed from the time when the air supply to the air dryer by the compressor is started and the air supply speed of the compressor. The air supply amount is calculated, and when the calculated air supply amount reaches the first threshold value, the control mode of the purge control valve is switched from the first control mode to the second control mode. The purge system according to any one of claims 1 to 3. A pressure sensor that measures the tank pressure and transmits the measured value of the tank pressure to the control unit is further provided.
The control unit switches the control mode of the purge control valve from the second control mode to the first control mode when the measured value is smaller than the pressure threshold value, any one of claims 1 to 6. Purge system described in. A vehicle comprising the purge system according to any one of claims 1 to 7. When an operation to stop the operation of the vehicle is detected, a stop operation detection unit for transmitting a stop operation detection signal notifying that the operation to be stopped has been detected is further provided.
When the control unit receives the stop operation detection signal, the control unit switches the control mode of the purge control valve from the first control mode to the second control mode.
The vehicle according to claim 8. 8. vehicle. When an operation instructing purging is detected, an instruction operation detection signal for notifying that the operation to be instructed has been detected and an instruction operation detection unit to be transmitted to the control unit are further provided.
When the control unit receives the instruction operation detection signal, the control unit switches the control mode of the purge control valve from the first control mode to the second control mode.
The vehicle according to claim 8.

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