JP2922677B2 - How to store engine limit output - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing an engine limit output in a hydraulic pump.

[0002]

2. Description of the Related Art The output torque of an engine constantly changes due to atmospheric conditions, fuel quality, aging and the like. However, at present, there is no means for compensating for this, so the torque is limited by a torque lower than the actual output torque on the load side of the engine with a margin. For this reason, at present, the engine output is not sufficiently used effectively.

There is also a method of controlling the load side of the engine based on the output characteristics of the engine. In this case, however, there are individual differences and changes in characteristics of the engine. There is a need to.

[0004]

SUMMARY OF THE INVENTION In view of the problems of the prior art, it is an object of the present invention to effectively measure and store the output characteristics of an engine in an actual operating state to effectively use the output of the engine.

[0005]

[Means for Solving the Problems]

(a) By means of setting the engine load to an arbitrary value,
By setting the load torque to zero and (b) setting the engine speed to an arbitrary value,
After setting a certain engine speed, (c) increasing the load torque by means for setting the load to an arbitrary value; (d) detecting the engine speed by means for detecting the engine speed at this time. The control rack position detection voltage detected by the means for detecting the engine speed and the control rack position is read. (E) The control rack position detection voltage corresponds to the read engine speed and the read engine speed. If it is determined that the voltage is less than or equal to the limit control rack position detection voltage at the time of the engine limit output stored in the memory,
The engine speed and load torque at that time are stored. (F) If the set engine speed is repeated by a predetermined number of points, the process is terminated. If not, the above (a) to ( The procedure of e) was performed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. Reference numeral 1 denotes a trial engine whose torque characteristics are to be checked, reference numeral 2 denotes an engine throttle position control device, and reference numeral 3 denotes a governor, which controls the fuel injection amount of the engine. Reference numeral 4 denotes a rack position detector for detecting a position RW of a control rack for controlling a fuel injection amount in the governor. Reference numeral 5 denotes a rotation speed detector for detecting the rotation speed NE of the engine. 6 is engine 1
Numeral 7 denotes a hydraulic proportional relief valve. Reference numeral 8 denotes a detector for the discharge pressure P of the hydraulic pump 6. Reference numeral 9 denotes a load setting device, and this output U is a relief valve 7
It is connected to the. Reference numeral 10 denotes a storage device for storing the torque characteristics of the engine 1. An engine throttle position setting device 11 is connected to the throttle position control device 2.

FIG. 2 shows a variable displacement pump 12 as a load device.
And a detector 13 for detecting the displacement of the pump 12. In this case, the load setting device 9 is connected to the control unit 14 of the pump 12.

FIG. 3 shows a braking device 15 as a load of the pump 1.
This is an example using. For example, the braking torque is controlled by the secondary pressure of the electromagnetic proportional pressure reducing valve 17. In this case, the load setting device 9 is connected to the electromagnetic proportional pressure reducing valve 17. The secondary pressure of the pressure reducing valve 17 is detected by the detector 16 and is connected to the storage device 10.

The load device is not limited to the above three examples, but may be any device capable of arbitrarily setting the load torque of the engine 1 by an external signal and detecting the load torque directly or indirectly. I just need.

FIG. 4 shows the relationship between the engine speed NE and the control rack position detection voltage RW at the time of engine limit output. RW = RWF (NE) ... where RWF is a function and engine speed NE and control as shown in FIG.
By monitoring the lurac position detection voltage RW, it is possible to make a determination at the time of engine limit output.

FIG. 5 is a flow chart for actually measuring and storing torque characteristics.
Is shown. The flow in the configuration example of FIG. 1 will be described.
(1) The command value U is output from the load setting device 9 so that the relief pressure of the relief valve 7 becomes zero, that is, the load becomes zero. (2) The throttle position is set via the throttle position control device 2 by the engine throttle position setting device 11. (3) A command value is output from the load setting device 9 so that the relief pressure of the relief valve 7 increases by ΔP to increase the load. (4) Engine speed N
E and the control rack position detection voltage RW are read.
(5) Compare the read RW with the RWF (NE) obtained by the equation. If RW ≦ RWF (NE), go to (6) and store. If RW> RWF (NE), go back to (3) to increase the load. . (6) From the relief pressure P and the displacement D of the hydraulic pump 6, a load torque TL is obtained from the following equation. TL = kD · P The engine speed NE and TL at this time are stored. (7) When the number of throttle points has been repeated, the process is completed. If not, go to the next throttle position
(1) to (6) are performed. The torque characteristics as shown in FIG. 6 are obtained by the above procedures (1) to (7).

In the configuration example of FIG. 2, the pump discharge amount is changed as a means for changing the engine load, and the load torque TL is obtained in the same manner as described above.

In the configuration example of FIG. 3, the braking torque is controlled as a means for changing the engine load. It is obtained by multiplying the secondary pressure P detected by the torque detector 16 by a proportional constant such as a reduction ratio.

[0014]

[Effect] In this way, the effective torque of the engine can be easily measured and stored for each system as it is on the vehicle, and it is possible to flexibly cope with individual differences and characteristic changes of the engine.
Further, if the torque on the load side is limited based on the torque characteristics obtained as described above, the engine output torque can be effectively used in the entire rotation speed region.

[Brief description of the drawings]

FIG. 1 is a wiring diagram of an apparatus for implementing the method of the present invention.

FIG. 2 shows another example of the means for changing the engine load.

FIG. 3 shows still another example of the means for changing the engine load.

FIG. 4 is a diagram showing a relationship between an engine speed NE and a control rack position detection voltage RW at an engine limit output.

FIG. 5 is a flowchart of the present invention.

FIG. 6 is a torque characteristic diagram obtained by the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sample engine 2 Throttle position control device 3 Governor 4 Rack position detector 5 Detector 6 Hydraulic pump 7 Relief valve 8 Detector 9 Load setting device 10 Storage device 11 Setting device 12 Variable displacement pump 13 Detector 14 Controller 15 Braking device 16 Detector 17 Electromagnetic proportional pressure reducing valve

Claims (1)

(57) [Claims] 1. A means for setting the load of an engine to an arbitrary value to zero the load, and (b) a means for setting the engine speed to an arbitrary value.
After setting a certain engine speed, (c) by means for setting the load torque to an arbitrary value,
(D) At this time, read the engine speed detected by the means for detecting the engine speed and the control rack position detection voltage detected by the means for detecting the control rack position. e) When the read control rack position detection voltage corresponds to the read engine speed and is determined to be equal to or less than the limit control rack position detection voltage at the time of engine limit output stored in the memory in advance. Is
The engine speed and load torque at that time are stored. (F) If the set engine speed is repeated by a predetermined number of points, the process is terminated. If not, the above (a) to ( A method for storing engine limit output, wherein the procedure of e) is performed.