JP4142169B2 - Compressed air filling device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressed air filling device for a vehicle, and more particularly to a compressed air filling device for a vehicle that quickly restores the pressure of compressed air in a reserve tank to a normal pressure even at an extremely low rotational speed such as during idling.
[0002]
[Prior art]
In general, an air compressor is mounted on a diesel engine for use in various air devices such as a braking device mounted on a vehicle, and compressed air generated by the air compressor is fed to a reserve tank.
The reserve tank contains compressed air at the normal pressure P. However, if the consumption of compressed air by the air device is large for extremely low speed operation such as idling, the reserve tank is not filled with compressed air. There is a fear. In particular, when an air compressor having a small discharge capacity is installed, it is required to rapidly restore the compressed air filling amount.
[0003]
Therefore, for example, as shown in Japanese Utility Model Publication No. 62-30905, a compressed air filling device for a vehicle is disclosed.
The compressed air filling device for a vehicle includes a pressure governor for controlling the operation of the air compressor so that the supply pressure from the air compressor falls within a predetermined range. Means for detecting the rapid filling state of air and means for forcibly holding the air compressor in the loaded state by releasing the control signal of the pressure governor based on the detection results of both means.
[0004]
[Problems to be solved by the invention]
However, in the above-described compressed air filling device for a vehicle, even when the vehicle is stopped and when the filling of compressed air is required rapidly, it still takes time to restore the compressed air in the reserve tank to the normal pressure. There is a problem that it takes. For example, it may be possible to fill the reserve tank with compressed air at a higher rotational speed than the normal idling rotational speed by depressing the accelerator pedal when the vehicle is stopped. It is difficult to determine the amount, and it is also difficult to determine how much the accelerator pedal is operated, and the operation is troublesome.
[0005]
Of course, if the discharge capacity of the air compressor is increased and the size is increased, the discharge amount of compressed air increases and the time required to restore the compressed air in the reserve tank to the normal pressure can be reduced. However, the weight of the air compressor itself increases and the vehicle It is not preferable in terms of weight reduction.
In addition, when the size of the air compressor is increased, part of the oil that lubricates the inside of the air compressor is mixed into the compressed air supplied from the air compressor (so-called oil take-out), and the oil in the compressed air enters the air equipment. There is a risk of adverse effects.
[0006]
The present invention has been made to solve the above-described problems, and its purpose is to use the compressed air when the pressure of the compressed air in the reserve tank decreases at an extremely low rotational speed such as during idling operation. It is an object of the present invention to provide a compressed air filling device for a vehicle that can quickly restore pressure.
[0007]
[Means for Solving the Problems]
The present invention relates to an electronic control device, a diesel engine equipped with an electronically controlled fuel injection device having an injection pump controlled by a command of the electronic control device, an air compressor that obtains compressed air by the power of the diesel engine, and the air In a compressed air filling device for a vehicle comprising a reserve tank for storing compressed air sent from a compressor at a normal pressure P2, a pressure sensor for detecting the pressure of the compressed air in the reserve tank is attached to the reserve tank, a pressure sensor on the input side of the electronic control unit, an engine rotational speed sensor is connected, the electronic control unit is set lower than the pressure P is the conventional pressure P2 of the compressed air in the reservoir tank at very low rotational speed operation becomes smaller than the threshold pressure P1 was injection a high signal of the rotational speed N2 than normal ultra-low rotational speed N1 Ri sent to pump, the reserve of compressed air in the tank rapidly filling the pressure P of the compressed air in the reservoir tank is higher than the threshold pressure P1, the internal pressure P is the conventional compressed air in the reservoir tank When the pressure becomes higher than the pressure P2, there is provided a rotation speed increasing means for sending a signal for returning to the normal extremely low rotation speed N1 to the injection pump .
[0008]
(Function)
In the present invention, the pressure P of the compressed air in the reserve tank is detected by the pressure sensor. A pressure signal is sent from the pressure sensor to the electronic controller. The engine speed sensor detects the speed of the diesel engine. A rotational speed signal is sent from the engine rotational speed sensor to the electronic control unit.
[0009]
The following processing is performed by the electronic control unit during extremely low speed operation such as idling operation. That is, it is determined by the electronic control unit whether or not the pressure P in the reserve tank is lower than the limit pressure P1, and the pressure P is lower than the limit pressure P1 set lower than the normal pressure P2 at the time of extremely low speed operation. If so, a signal having a rotational speed N2 higher than the normal extremely low rotational speed N1 is sent to the injection pump.
[0010]
As a result, the reserve tank is rapidly filled with compressed air, and the pressure P in the reserve tank increases. The pressure P exceeds the set pressure P1 and is restored to the normal pressure P2.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
A vehicle compressed air filling apparatus according to the present embodiment will be described with reference to FIGS. In the present embodiment, the idling operation will be described as an example at the time of extremely low speed operation.
In FIG. 1, an air compressor 2 is attached to a diesel engine 1. The rotation of the crankshaft (not shown) of the diesel engine 1 is transmitted to the input shaft 2A of the air compressor 2 via the gears 3 and 4. The air compressor 2 has a structure that obtains compressed air by the power of the diesel engine 1, as is well known. The structure of the air compressor 2 is, for example, the structure of the chassis edited by the National Institute of Automotive Maintenance Association [II] P76, 77 May 25, the second edition was issued).
[0013]
An input port 6 </ b> A of the reserve tank 6 is connected to the output port 2 </ b> B of the air compressor 2 through a supply pipe 5. The adjustment valve 2C of the air compressor 2 and the reserve tank 6 are connected via a pilot pipe 7. A pressure governor 8 is attached in the middle of the pilot pipe 7. The pressure governor 8 controls the operation of the air compressor 2 so that the compressed air from the air compressor 2 to the reserve tank 6 becomes the normal pressure P2 (see, for example, Japanese Utility Model Publication No. 62-30905). Here, the normal pressure P2 is set to a certain pressure range between the upper limit value and the lower limit value.
[0014]
The reserve tank 6 is equipped with a pressure sensor 9 that detects the pressure of the compressed air in the reserve tank 6.
On the other hand, the diesel engine 1 includes an electronic fuel injection device 10. The electronic fuel injection device 10 controls an amount of movement of a fuel injection pump 11 and a control rack (not shown) of the fuel injection pump 11. 12. The pressure sensor 9, the engine speed sensor 13, and the like are connected to the input side of the electronic control device 12. The output side of the electronic control unit 12 is connected to the fuel injection pump 11. The function of the electronic control unit 12 is well known, and the control rack of the fuel injection pump 11 is moved by a command from the electronic control unit 12, the amount of fuel injection in the fuel injection pump 11 is increased or decreased, and the engine speed changes.
[0015]
The operation in this embodiment will be described with reference to the flowchart of FIG.
The electronic control unit 12 stores a normal pressure P2, a limit pressure P1, a normal idling set rotational speed N1 , and a rotational speed N2. The limit pressure P1 is a value lower than the normal pressure P2 (lower limit value). The rotation speed N2 is a rotation speed set higher than the normal idling setting rotation speed N1.
[0016]
In the figure, the pressure sensor 9 detects the pressure of the compressed air in the reserve tank 6 and sends a pressure signal to the electronic control unit 12.
The engine speed sensor 13 detects the speed of the diesel engine 1 and sends a speed signal to the electronic control unit 12.
The electronic control device 12 performs the following operations as shown in the flowchart of FIG.
[0017]
The electronic control unit 12 determines whether or not the compressed air filling amount in the reserve tank 6 is sufficient through the determination of the pressure P of the compressed air in the reserve tank 6. That is, the electronic control unit 12 determines whether or not the pressure P of the compressed air in the reserve tank 6 is lower than the limit pressure P1 (S1). If the pressure P is lower than the limit pressure P1, the pressure sensor 9 is A signal to that effect is sent to the electronic control unit 12, and when the pressure P is higher than the limit pressure P1, normal fuel injection control is performed (S8).
[0018]
Subsequently, the electronic control unit 12, the rotational speed N is determined Do dolphin not exceed idling set rotational speed N1, when the rotation speed N is lower than the idle set speed N1, the rotational speed N is speed N2 (S2, S3, S4). Here, the rotation speed N2 is a rotation speed set higher than the normal idling setting rotation speed N1. The reason why the idling set rotational speed N1 is used as a reference is as follows. When the rotation speed N is lower than the idling setting rotation speed N1, if the pressure P of the compressed air in the reserve tank 6 decreases , the time until the pressure P of the compressed air in the reserve tank 6 is restored to the normal pressure P2 On the other hand, if the rotational speed N is higher than the idling set rotational speed N1, the time until the compressed air pressure P is restored to the normal pressure P2 even if the compressed air pressure P in the reserve tank 6 decreases. This is because it is short.
[0019]
By the above-described processing of the electronic control device 12, a signal of the rotational speed N2 is sent to the fuel injection pump 11, the compressed air is rapidly filled in the reserve tank 6, and the pressure P of the compressed air in the reserve tank 6 is increased. The
At the time of idling, again, by the electronic control unit 12, the pressure P is dolphin whether it is determined beyond the limit pressure P1 (S5), when the pressure P is lower than the limit pressure P1 is at a rotational speed N2 Filling with compressed air continues . Here, the determination of whether or not the pressure P has increased and exceeded the limit pressure P1 (S5) is performed again in the normal fuel injection control process in a state where the pressure P has increased and exceeded the limit pressure P1. This is for continuing the series of processes for filling the compressed air without performing (S8).
[0020]
When the pressure P of the compressed air in the reserve tank 6 becomes higher than the limit pressure P1 by the electronic control unit 12, the following processing (S6, S7) is performed. That is, with increasing pressure P of the compressed air in the reserve tank 6, by the electronic control unit 12, the pressure P is determined whether greater than usual pressure P2, if the pressure P is lower than the conventional pressure P2 is Then, it is continued to fill the reserve tank 6 with the compressed air at the rotational speed N2 (S6) , and when the pressure P becomes higher than the normal pressure P2, it is determined that the filled amount of the compressed air in the reserve tank 6 is sufficient, The rotational speed is returned to the idling set rotational speed N1 (S7).
[0021]
Thereby, only when the filling amount of the compressed air in the reserve tank 6 is insufficient, the filling of the compressed air into the reserve tank 6 at the rotational speed N2 is continued, and the filling amount of the compressed air in the reserve tank 6 is continued. When there is a sufficient amount of fuel, wasteful consumption of fuel is prevented without unnecessarily increasing the rotational speed. The above processing is repeatedly performed by the electronic control unit 12.
[0022]
According to the above configuration, the following effects can be obtained.
When the pressure P of the compressed air detected by the pressure sensor 9 during the idling operation becomes lower than the limit pressure P1, the electronic control device 12 sends a signal of the rotational speed N2 higher than the normal idling set rotational speed N1 to the fuel injection pump 11. Sent.
Therefore, the air compressor 2 is operated by the electronic control device 12 at a set rotational speed N2 higher than the normal idling set rotational speed N1, the compressed air is filled in the reserve tank 6 in a short time, and the compressed air becomes the normal pressure P2. Time to restore can be shortened.
[0023]
As a result, the air compressor 2 can be reduced in size, and even with such a design, it is possible to prevent insufficient supply of compressed air during idling operation. Further, as the air compressor 2 is reduced in size, the weight of the vehicle is reduced, so that the capacity of the auxiliary machinery can be reduced and fuel consumption can be reduced.
Furthermore, along with the downsizing of the air compressor 2, it is possible to prevent a part of the oil that lubricates the air compressor 2 from being mixed into the compressed air supplied from the air compressor 2, and the oil in the compressed air is compressed into the air. The effect which can eliminate the possibility of having a bad influence on an apparatus is produced.
[0024]
In the present embodiment, the idling operation is described as an example at the time of extremely low speed operation, but the operation other than the idling operation is also included at the time of extremely low speed operation.
[0025]
In the present embodiment, the example in which the normal pressure P2 is set to a constant pressure range between the upper limit value and the lower limit value has been described. However, the normal pressure P2 may be a constant value.
[0026]
【The invention's effect】
According to the present invention, even when the pressure of the compressed air in the reserve tank decreases during an extremely low speed operation such as an idling operation, the electronic control device causes the set rotational speed N2 to be higher than the normal idling set rotational speed N1. Since the air compressor is activated and the reserve tank is filled with compressed air in a short time, the time until the compressed air is restored to the normal pressure P2 can be shortened.
[0027]
As a result, the air compressor can be reduced in size, and even with such a design, it is possible to prevent insufficient supply of compressed air during idling operation of the diesel engine. Further, as the air compressor is reduced in size, the weight of the vehicle is reduced, so that the capacity of the auxiliary equipment is reduced and fuel consumption can be reduced.
Furthermore, along with the downsizing of air compressors, the compressed air supplied from the air compressor is prevented from mixing part of the oil that lubricates the inside of the air compressor, and the oil in the compressed air adversely affects the air equipment. The effect which can eliminate the fear of giving is produced.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a compressed air filling device for a vehicle according to the present embodiment.
FIG. 2 is a flowchart in the present embodiment.
[Explanation of symbols]
1 diesel engine 2 air compressor 6 reserve tank 9 pressure sensor 10 electronic fuel injection device 11 fuel injection pump 12 electronic control device 13 engine speed sensor

Claims (1)

An electronic control device, a diesel engine equipped with an electronically controlled fuel injection device having an injection pump controlled by a command of the electronic control device; and
An air compressor that obtains compressed air with the power of the diesel engine;
In a compressed air filling apparatus for a vehicle, comprising a reserve tank that accommodates compressed air sent from the air compressor at a normal pressure P2.
A pressure sensor for detecting the pressure of compressed air in the reserve tank is attached to the reserve tank,
A pressure sensor and an engine speed sensor are connected to the input side of the electronic control unit;
The electronic control device
When the pressure P of the compressed air in the reservoir tank at very low rotational speed operation becomes smaller than the threshold pressure P1, which is set lower than the conventional pressure P2, high speed N2 signal than normal ultra-low rotational speed N1 skip forward to the injection pump, the pressure P of the compressed air in the reserve tank rapidly filled with compressed air in the reserve tank is higher than the threshold pressure P1, the internal pressure P of the compressed air in the reserve tank A compressed air filling device for a vehicle, comprising a rotation speed increasing means for sending a signal for returning to the normal extremely low rotation speed N1 to the injection pump when the pressure becomes higher than the normal pressure P2 .

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