JP2974336B2 - Engine speed control method for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an engine speed control method applied to a construction machine such as a hydraulic shovel.

<Conventional Technology> Some conventional construction machines, for example, hydraulic shovels, electrically control the engine speed. In such a hydraulic shovel, an auto-idle mode selection switch connected to a controller having storage and calculation functions,
A work mode selection switch, an engine speed control switch, and the like are provided. The above-mentioned auto idle mode selection switch automatically lowers the engine speed to the value corresponding to the auto idle mode set value stored in the controller in advance when the machine is in an idle state when the machine is not working, thereby reducing unnecessary energy consumption. It is a switch to hold down. In addition, the above-mentioned work mode selection switch is, for example, a maximum engine speed suitable for a work mode requiring power such as a rock removal work requiring maximum capacity (hereinafter referred to as P mode), that is, stored in the controller in advance. The engine mode is automatically controlled to the engine speed corresponding to the set P-mode setting value, or the most efficient work mode (hereinafter referred to as E) in consideration of fuel efficiency of an object requiring a moderate force such as excavation of earth and sand. Mode), which is automatically controlled to a relatively high engine speed, ie, the engine speed corresponding to the E-mode set value stored in the controller in advance, or with extremely small force such as bucket leveling work. A low engine speed suitable for a sufficient work mode (hereinafter referred to as L mode), Or automatically controlled by the engine speed corresponding to the stored is L mode setting value is selected to switch.

The above-described engine speed control switch may be, for example, a dial-type switch or a switch configured with two switches, ie, a switch for increasing the number of revolutions and a switch for decreasing the number of revolutions. Unlike an automatic idle mode selection switch or a work mode selection switch for automatically controlling the engine speed, the electric control is manually performed at the engine speed intended by the operator.

In a conventional hydraulic shovel equipped with such an automatic idle mode selection switch or a work mode selection switch,
In each normal work, from the viewpoint of easiness of operation and securing of work accuracy, etc., the operation of the automatic idle mode selection switch without manual manual complicated engine speed control by the engine speed control switch, The engine speed is automatically controlled by operating a work mode selection switch according to the type of work, and the corresponding work is performed.

<Problems to be Solved by the Invention> However, the work mode setting values such as the auto idle mode setting value, the P mode setting value, the E mode setting value, and the L mode setting value in the conventional hydraulic shovel described above are standard. It is set in advance in consideration of various working conditions, and therefore cannot always be a mode setting value that gives a suitable engine speed under actual working conditions. If it is desired to cope with work conditions different from the standard work conditions, the controller has to be replaced conventionally, which increases the cost, and requires complicated work such as adjustment of each device. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances in the related art, and an object thereof is to provide a method of controlling an engine speed of a construction machine that can easily change a mode setting value without requiring replacement of a controller. It is in.

<Means for Solving the Problems> In order to achieve this object, the present invention stores, in advance, a set value of the engine speed corresponding to each of a plurality of different modes individually as a mode set value,
A corresponding predetermined mode setting value among the individually stored mode setting values is selected according to a mode selection signal related to a predetermined mode among the plurality of different modes, and the selected predetermined mode setting is selected. In the engine speed control method for a construction machine, which automatically controls the engine speed to be equal to the value, in a state where a mode selection signal relating to a predetermined mode among the plurality of different modes is output. When a predetermined specific signal is output, a mode setting value corresponding to the mode selection signal among the individually stored mode setting values and the predetermined specific signal are added to add the predetermined mode. The new mode setting value according to the above, and a value within a range of a predetermined minimum rotation speed and a predetermined maximum rotation speed set in advance in relation to the predetermined mode, Shall apply in the output of the mode selection signal according to the mode are the configuration for controlling so that the engine rotational speed corresponding to the new mode setting.

<Operation> Since the present invention is configured as described above, the mode set value can be changed only by performing the signal processing using the specific signal and the mode selection signal, that is, the engine speed corresponding to the mode set value is set to the working condition. The engine speed can be easily changed to a suitable one, and there is no need to replace the controller.

<Embodiment> Hereinafter, a method for controlling an engine speed of a construction machine according to the present invention will be described with reference to the drawings.

1 to 3 are explanatory views showing an embodiment of the present invention.
FIG. 1 is a block diagram showing a basic configuration of a control portion of a hydraulic shovel to which this embodiment is applied. FIG. 2 is a flowchart showing a processing procedure performed by a controller constituting the control portion shown in FIG. FIG. 3 is a characteristic diagram showing the contents of processing in a controller constituting the control part shown in FIG.

FIG. 1 shows a configuration of a control portion of a hydraulic shovel, which is an example of a construction machine. A controller 1 having storage and calculation functions is provided with an auto idle mode selection switch 2, a work mode selection switch 3, and An engine speed control switch 6 having a number increasing switch 4 and a speed decreasing switch 5 is connected to a step motor 8 for controlling the driving of an engine governor 7 for controlling the fuel injection amount of the engine. Mode setting values shown in FIG. 3 corresponding to each work mode are stored in the controller 1 in advance. That is, the third is the figure is a characteristic diagram showing the relationship between engine speed and (rpm) engine output (PS) and a hydraulic pump absorption horsepower in the FIG. 3, N ₁ is the reference value of the P-mode, i.e. the standard a maximum speed which is preset in consideration of the specific operating conditions, Ns ₁ is the engine rotation speed which is preset as a minimum value of P mode setting. That is, the P-mode set value is determined in advance so as to take a range from Ns ₁ to N ₁ . Similarly, N ₂ is the reference value of the E-mode, that is, a value smaller than N ₁ at a rotation speed that is set in advance in consideration of the standard working conditions, Ns ₂ is the minimum value of the E-mode setpoint Ne ₂ is an engine speed preset in advance as the maximum value of the E mode set values. That is, the E mode setting value is
It is predetermined so that the range from Ns ₂ to Ne ₂ can be taken. Furthermore, N ₃ is the reference value of the L mode, and the reference value of the auto idle mode, that is, less than N ₂ at a rotation speed that is set in advance in consideration of the standard working conditions, Ns ₃ is L mode As the minimum value of the set value and the auto idle mode set value, Ne ₃ is an engine speed previously set as the maximum value of the L mode set value and the auto idle mode set value, respectively. That is, the L mode set value and the auto idle mode set value are predetermined so as to be in a range from Ns ₃ to Ne ₃ . The range of the engine speed Ns ₁
And to N _1, and Ns ₂ ~Ne _2, Ns ₃ ~Ne3 without overlapping each other and the engine rotational speed Ns ₃ is are the large value sufficiently higher than the engine rotational speed of the engine stall range.

In this embodiment, a plurality of specific signals, for example, a rotational speed increasing signal output from the rotational speed increasing switch 4, a rotational speed decreasing signal output from the rotational speed decreasing switch 5, and the aforementioned auto signal The idle mode selection signal is processed to change the set value of the auto idle mode. The signal for increasing the number of revolutions and the signal for decreasing the number of revolutions, and the above-mentioned working mode selection signals, that is, the P mode selection signal and the E mode The work mode setting value corresponding to either the selection signal or the L mode selection signal, that is, P
One of the mode set value, the E mode set value, and the L mode set value is changed.

The signal processing for changing the mode setting value as described above will now be described with reference to the flowchart of FIG.

First, as shown in step S1 of FIG. 2A, each signal, that is, an auto idle mode selection signal, a work mode selection signal, a rotation speed increasing signal, and a rotation speed decreasing signal is input to the controller 1. Next, the procedure proceeds to step S2, where it is determined whether the rotation speed increasing signal and the rotation speed decreasing signal are both input. Here, when both the rotation speed increasing signal and the rotation speed decreasing signal are input and the determination in step S2 is satisfied, the two switches 4 and 5 are simultaneously pressed,
The case where the change of the mode set value is intended, and the case where the determination in the step S2 is not satisfied, is the case where the change of the mode set value is not intended.

First, a case where the determination in step S2 is not satisfied will be described. Proceeding to step S3, it is determined whether an auto idle mode selection signal has been input. If the determination in step S3 is satisfied, the process proceeds to step S4, in which a preset auto idle mode set value, for example, the above-described reference value N ₃
Drive signal corresponding to the output from the controller 1 when the neutral of the machine stepper motor 8, which in Yotsute engine cabana 7 is controlled, auto idle control is performed so that the engine rotational speed is N _3. If the determination in step S3 is not satisfied, or after the processing in step S4, the process proceeds to step S5. In this step S5, it is determined whether or not a work mode selection signal has been input. If this determination is satisfied, the procedure moves to step S6. Execution of the corresponding working mode, i.e. the working mode so that the engine speed corresponding to the reference value N ₁ If for example the above-mentioned case of a P mode, and corresponds to the reference value N ₂ if for example the aforementioned case of the E mode as the engine speed and the drive signal to the step motor 8 from the controller 1 so that the engine speed corresponding to the reference value N ₃ if for example the above-mentioned case of the L-mode is output, desired working mode execution Is done. Also,
If the judgment in step S5 is not satisfied, or
After the processing in S6, the procedure moves to step S7. In this step S7, it is determined whether or not the rotation speed increasing signal is input. If this determination is satisfied, the operator is trying to increase the engine speed by manual operation by operating the engine speed control switch 6;
In step S8, a drive signal corresponding to the value of the rotation speed increasing signal is output from the controller 1 to the step motor 8, thereby increasing the engine rotation speed. If the determination in step S7 is not satisfied, or after the process in step S8, the process proceeds to step S9. In this step S9, it is determined whether or not a signal for reducing the number of revolutions is input. If this determination is satisfied, the operator is trying to reduce the engine speed by manual operation, and the process proceeds to step S10, where a drive signal corresponding to the value of the speed reduction signal is sent from the controller 1. The output is output to the step motor 8, whereby the engine speed decreases. If the determination in step S9 is not satisfied, and after the processing in step S10, the process returns to the beginning.

Then, when the determination of the above-described procedure S2 is satisfied, that is, when the change of the mode setting value is intended, the process proceeds to procedure S11. This procedure S11, and sets the reference value N ₃ defined the auto idle mode setting value in advance, set to a reference value determined working mode setting value in advance. That is, N ₁ is a reference value P mode setting value, the N ₂ is the reference value E mode setting value, respectively set L mode setting value N ₃ is the reference value. Next, the procedure moves to step S12. In this step S12, it is determined whether or not the auto idle mode selection signal has been input.

If the determination in step S12 is satisfied, it is intended to change the set value of the auto idle mode.
Move on to step S13. This procedure S13, and sets the auto idle mode setting value Ns ₃ for example, the minimum value, then proceeds to step S14. Predetermined value the auto idle mode setting value in this procedure S14, i.e. performs calculation increases by a unit change amount .DELTA.N _3. Next, the procedure moves to step S15. This procedure S15, auto idle mode setting value is determined whether the maximum value Ne ₃ smaller. If the determination in step S15 is satisfied, the process moves to step S16. In this step S16, it is determined whether or not both the rotational speed increasing signal and the rotational speed decreasing signal are input. If the determination in step S16 is satisfied, both the speed increasing switch 4 and the speed decreasing switch 5 are subsequently operated, and the operator sets the auto idle mode set value to a value larger than Ns ₃ + ΔN _3. It is the case that it is intended to
Return to Then, in the procedure S14, calculation adding unit variation .DELTA.N ₃ to auto idle mode setting value Ns ₃ + _{ΔN 3} is performed. Hereinafter, similarly, the processing of steps S14 to S16 is repeated until the set value of the auto idle mode becomes a value intended by the operator. When the set value of the auto idle mode becomes the value intended by the operator, it means that the operation of the rotation speed increasing switch 4 and the rotation speed decreasing switch 5 is stopped, and the determination in the step S16 is satisfied. Since it is gone, return to the beginning. Note that the above procedure
The decision of step S15 is not satisfied, the process proceeds to step S17, if the auto idle mode setting value exceeds the maximum value Ne _3, this procedure
S17 process of setting the auto idle mode setting value to the maximum value Ne ₃ is performed, the flow returns to the beginning. That is, in this embodiment, the set value of the auto idle mode can be set to a predetermined value desired by the operator within a range from Ns ₃ + ΔN ₃ to Ne ₃ , and the maximum value is forcibly limited to Ne ₃ . In this state, when only the auto idle mode selection switch 2 is operated and the auto idle mode selection signal is input to the controller 1, the above-described procedures 1, 2, 3, and 4 of FIG. After that, the auto idle control is executed. That is, when the machine is in neutral,
Control is performed to automatically reduce the engine speed to the auto idle mode set value changed in S14 to S16 or step S17.

If the determination in step S12 in FIG. 2A is not satisfied, the process proceeds to step S18 in FIG. 2B. This step S18
Then, it is determined whether a work mode selection signal has been input. If the determination in step S18 is not satisfied, the process returns to the beginning when it is intended to simply reset the set values of the auto idle mode and the work mode to the reference values.

If the determination in step S18 is satisfied, it means that a change in the work mode set value is intended, and the process proceeds to step S19. In this step S19, it is determined whether the work mode selection signal is a P mode selection signal.

If the determination in step S19 is satisfied, the process moves to step S20. This procedure S20, sets the P mode set value Ns ₁ is the minimum value, for example, then proceeds to step S21. This step S2
In 1, the P mode set value is set to a predetermined value, that is, a unit change amount ΔN ₁
Perform an operation to increase only Next, the procedure moves to step S22. This procedure S22, P mode setting value is determined whether the maximum value N ₁ is smaller than. If the determination in step S22 is satisfied, the process moves to step S23. In this step S23, it is determined whether both the rotational speed increasing signal and the rotational speed decreasing signal are input. If the determination in step S23 is satisfied, both the rotation speed increasing switch 4 and the rotation speed decreasing switch 5 are subsequently operated, and the operator sets the P mode set value to a value larger than Ns ₁ + ΔN _1. This is the case, and the process returns to the above-described step S21. And in this procedure S21, calculation applied to the auto idle mode setting value Ns ₁ + _{ΔN 1} to unit variation .DELTA.N ₁ is performed. Hereinafter, similarly, the processing of steps S21 to S23 is P
The mode setting value is repeated until the operator's intended value is reached. When the set value of the P mode becomes the value intended by the operator, it means that the operation of the switch 4 for increasing the number of revolutions and the switch 5 for decreasing the number of revolutions are stopped, and the judgment in the step S23 is not satisfied. So return to the beginning. Incidentally, not satisfied a determination is above procedure S22, the process P mode setting value is shifted to step S24, when exceeding the maximum value N _1, to set the P mode setting value in this step S24 to the maximum value N ₁ It is done and returns to the beginning. That is, in this embodiment, the P-mode set value can be set to a value desired by the operator in a range from Ns ₁ + ΔN ₁ to N ₁ , and the maximum value is forcibly limited to N ₁ . When the work mode selection switch 3 is operated to select the P mode in such a state, the steps S1, 2, and S3 in FIG.
The control in the P mode is executed via 3, 5, and 6. That is, the engine speed is automatically controlled to the engine speed corresponding to the P-mode set value changed in steps S21 to S23 or S24.

If the determination in the step S19 is not satisfied, the process moves to the step S25. In this step S25, it is determined whether the work mode selection signal is an E mode selection signal. This step S25
If the determination is satisfied, the process moves to step S26. This step S
In 26 sets the E mode setting value Ns ₂ is a minimum value, for example, then proceeds to step S27. Predetermined value E mode setting value in this procedure S27, i.e. performs calculation increases by a unit change amount .DELTA.N _2. Next, the procedure moves to step S28. This step S28
In, E mode setting value is determined whether the maximum value Ne ₂ smaller. If the determination in step S28 is satisfied, the process moves to step S29. In this step S29, it is determined whether both the rotational speed increasing signal and the rotational speed decreasing signal are input. If the determination in step S29 is satisfied, both the rotation speed increasing switch 4 and the rotation speed decreasing switch 5 are subsequently operated, and the operator sets the E mode set value to a value larger than Ns ₂ + ΔN _2. This is the case when the user intends to do so, and the process returns to step S27 described above. Then, in this step S27, an operation of adding the unit change amount ΔN ₂ to the E mode set value Ns ₂ + ΔN ₂ is performed. Hereinafter, similarly, the processing of steps S27 to S29 is repeated until the E-mode set value becomes a value intended by the operator. When the E-mode setting value reaches the value intended by the operator, it means that the operation of the rotation speed increasing switch 4 and the rotation speed decreasing switch 5 is stopped, and the determination in step S29 is satisfied. Return to the beginning because it is gone. Incidentally, not satisfied a determination is above procedure S28, if the E mode setting value exceeds the maximum value Ne ₂ moves to Step S30, a process of setting the E mode setting value in this step S30 the maximum value Ne ₂ It is done and returns to the beginning.
That is, in this embodiment, the E mode set value is set to Ns ₂ + ΔN ₂
To Ne ₂ can be set as desired by the operator, and the maximum value is forcibly limited to Ne ₂ . When the work mode selection switch 3 is operated to select the E mode in such a state, the control of the E mode is executed through the procedures S1, 2, 3, 5, and 6 in FIG. Is done. That is, the engine speed is automatically controlled to the engine speed corresponding to the E-mode set value changed in steps S27 to S28 or S30.

If the determination in the step S25 in FIG. 2B is not satisfied, the process proceeds to the step S31. In this step S31, L
Set the mode setting value Ns ₃ for example, the minimum value, then proceeds to step S32. In this step S32, a calculation for increasing the L mode set value by a predetermined value, that is, the unit change amount ΔN ₃ is performed. Next, the procedure moves to step S33. This procedure S33, L mode setting value is determined whether the maximum value Ne ₃ smaller. If the determination in step S33 is satisfied, the process moves to step S34. In this step S34, it is determined whether both the rotational speed increasing signal and the rotational speed decreasing signal are input. If the determination in step S34 is satisfied, both the rotation speed increasing switch 4 and the rotation speed decreasing switch 5 are subsequently operated, and the operator sets the L mode set value.
This is the case where it is intended to make the value larger than Ns ₃ + ΔN ₃ , and the process returns to the above-described step S32. And in this procedure S32, operations become to put adding unit variation .DELTA.N ₃ to L mode setting value Ns ₃ + _{ΔN 3.} In the same manner, the processes in steps S32 to S34 are repeated until the L mode set value reaches the value intended by the operator. When the L mode set value reaches the value intended by the operator, it means that the operation of the rotation speed increasing switch 4 and the rotation speed decreasing switch 5 is stopped, and the determination in step S34 is not satisfied. Return to the beginning. Note that the determination in the above step S33 is not satisfied, and L
If the mode setting value exceeds the maximum value Ne ₃ moves to step S35, processing for setting the L mode setting value in this step S35 the maximum value Ne ₃ is performed, the flow returns to the beginning. That is, in this embodiment, the L mode set value can be set to a value desired by the operator within the range from Ns ₃ + ΔN ₃ to Ne ₃ , and the maximum value is forcibly limited to Ne ₃ . When the work mode selection switch 3 is operated to select the L mode in such a state, the procedures S1, 2, and S3 shown in FIG.
The control in the P mode is executed via 3, 5, and 6. That is, the engine speed is automatically controlled to the engine speed corresponding to the L mode set value changed in the above-described steps S32 to S34 or step S35.

As described above, in this embodiment, by operating the auto idle mode selection switch 2 or the work mode selection switch 3 together with the rotation speed increasing switch 4 and the rotation speed decreasing switch 5, the automatic idle mode is switched. The set values can be easily changed in the range of approximately Ns _{3 to} Ne ₃ , and each work mode set value, that is, the P mode set value, the E mode set value, and the L mode set value are respectively substantially set to Ns ₁ to N 3 shown in FIG. N _1, Ns ₂ ~Ne can be easily changed in the range of _2, Ns _{3 ~Ne 3.} Therefore, the mode setting value can be changed to a mode setting value suitable for special working conditions different from the standard working conditions without any replacement of the controller 1, and the cost associated with the replacement of the controller 1 is not increased. Also, there is no need for complicated equipment adjustment work.

FIG. 4 is a block diagram showing a basic configuration of a control portion of a hydraulic shovel to which another embodiment of the present invention is applied. The engine speed control switch 6a shown in FIG. 4 is configured, for example, as a dial type,
The counterclockwise operation manually increases or decreases the engine speed. Reference numeral 9 denotes an engine speed setting switch. In this alternative embodiment, the signal output from the engine speed setting switch 9 is a specific signal relating to a change in the mode setting value.

That is, when changing the set value of the auto idle mode, the operator only has to operate the switch 9 for setting the engine speed together with the switch 2 for selecting the automatic idle mode, or the switch 9 for setting the engine speed together with the switch 3 for selecting the work mode. By doing so, the corresponding mode setting value can be changed by the signal processing in the controller 1 in the same manner as in the procedure shown in FIGS. 2 (a) and 2 (b) described above.

In the control method performed in this manner, the mode set value can be easily changed without changing the controller 1, that is, the engine speed corresponding to the mode set value can be easily changed. The same operation and effect as those of the embodiment shown in FIG.

<Effect of the Invention> Since the method for controlling the engine speed of a construction machine according to the present invention is configured as described above, the mode setting value can be easily changed without requiring replacement of the controller. That is, when the mode selection signal relating to the predetermined mode is being output, the mode setting value of the predetermined mode is changed to a predetermined minimum rotation speed and a predetermined maximum speed preset in association with the predetermined mode. It can be easily changed as a value within the range of the number of revolutions, so that when changing the mode setting value, the cost can be reduced as compared with the conventional one, and complicated adjustment work of the equipment is not required. it can.

[Brief description of the drawings]

1 to 3 are explanatory views showing an embodiment of a method of controlling the engine speed of a construction machine according to the present invention. FIG. 1 shows a basic configuration of a control part of a hydraulic shovel to which this embodiment is applied. FIG. 2 is a flowchart showing a processing procedure performed by a controller constituting the control section shown in FIG. 1, and FIG. 3 is a characteristic showing the contents of processing in the controller constituting the control section shown in FIG. FIG. 4 is a block diagram showing a basic configuration of a control portion of a hydraulic shovel to which another embodiment of the present invention is applied. 1 ... Controller, 2 ... Auto-idle mode selection switch, 3 ... Work mode selection switch, 4 ... Rotation increase switch, 5 ... Rotation decrease switch, 6,
6a: Engine speed control switch, 7: Engine governor, 8: Step motor, 9: Engine speed setting switch

Claims (1)

(57) [Claims] An engine speed setting value corresponding to each of a plurality of different modes is individually stored in advance as a mode setting value, and a mode selection signal relating to a predetermined mode among the plurality of different modes is provided. And selects a corresponding predetermined mode setting value among the individually stored mode setting values, and automatically controls the engine speed to be equal to the selected predetermined mode setting value. In the method for controlling the engine speed of a construction machine, when a predetermined specific signal is output in a state where a mode selection signal relating to a predetermined mode among the plurality of different modes is output, the individual storage is performed. A mode setting value corresponding to the mode selection signal of the set mode setting values, and the predetermined specific signal are added to add a new mode related to the predetermined mode. The mode setting value is obtained as a value within a range between a predetermined minimum rotation speed and a predetermined maximum rotation speed that are set in advance in relation to the predetermined mode, and is set during the output of the mode selection signal related to the predetermined mode. A method for controlling an engine speed of a construction machine, wherein the engine speed is controlled to be equal to the new mode setting value.