JP3172273B2 - Engine speed control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine speed control device suitable for controlling the engine speed of a diesel engine mounted on a construction machine or the like.

[0002]

2. Description of the Related Art Generally, construction machines such as cranes are equipped with an accelerator lever for controlling the engine speed, and an accelerator pedal for finely controlling the engine speed during operation. In this case, the governor lever of the engine is rotationally controlled such that the accelerator lever and the accelerator pedal are mechanically connected and the engine speed is controlled at the maximum value of the two.

On the other hand, when performing a bucket operation with a crawler crane, the operator always uses the main winding brake and the auxiliary winding brake, so that the engine cannot be controlled using the accelerator pedal. For this reason, an accelerator grip is provided on a grip portion such as a turning operation lever, so that the engine speed can be finely controlled even during bucket work.

As described above, in order to prevent the operability of the engine speed control from being impaired in both cases where the crawler crane is used for both the crane work and the bucket work, it is necessary to (1) set a constant rotation. Suitable accelerator lever (2) Accelerator pedal suitable for crane work (3) Accelerator grip suitable for bucket work is required. In this case, mechanically connecting the accelerators not only complicates the device and increases the cost, but also has the disadvantage of increasing the operating force and deteriorating the operability.

Therefore, it is conceivable that the operation of the plurality of accelerator operation members is electrically detected to electrically control the engine governor. JP-A-51-138235
The engine speed control device disclosed in Japanese Patent Application Laid-Open Publication No. H11-209703 detects an accelerator operation amount and a throttle opening with a potentiometer, and opens and closes a throttle valve with a reversible motor based on these values. The rotation speed control device disclosed in Japanese Patent Application Laid-Open No. 61-145849 detects an accelerator operation amount and a governor adjustment amount with a potentiometer or the like, and controls the governor adjustment amount with a reversible motor based on these detected values.

[0006]

When such a conventional engine speed control method is applied to an apparatus having a plurality of operating members as described above, the number of rotations is controlled by the maximum operation amount of each operating member. It is possible that
There are the following problems.

(1) In general, since the accelerator lever and the accelerator grip are configured to be fixed at an arbitrary operation position, if one of the accelerator levers and the accelerator grip is fixed to the high rotation side, the engine speed suddenly increases when the engine is started. Starts the engine. (2) The accelerator pedal is normally biased by a spring so as to return to the low speed (idle speed) side. However, if the return operation by the return spring is impaired, the accelerator pedal is mechanically restrained, The engine is started at a high speed when the engine is started. In addition, when the engine speed is controlled by the maximum operation amount among the plurality of operation members as described above, if the return operation is impaired, the engine speed is reduced to a speed equal to or lower than the rotation speed determined by the restrained position of the accelerator pedal. Can not lower.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an engine speed control device that starts an engine at a low speed when the engine is started and does not impair the operability of an accelerator.

[0009]

The present invention will be described with reference to FIG. 1 which is a claim correspondence diagram . (1) A first operation member 101a capable of instructing an arbitrary engine speed according to an operation amount and holding the engine speed even when the operating force is released, and an operation amount At least a second operating member 101b capable of returning to a predetermined engine speed when the operating force is released, based on a command of the engine speed from each operating member. The present invention is applied to an engine speed control device that controls the engine speed. The object is to respond to input of a timing signal and first and second detecting means 102a and 102b for detecting command values Na and Nb of the engine speed by the first and second operating members 101a and 101b, respectively. Command value N of the engine speed by the first and second operating members 101a and 101b.
ai, Nbi, respectively, first and second storage means 103a, 103b, and at least detection means 102
a, Nb detected in the storage means 103a, 103b and the command values Nai, Nb detected in the storage means 103a, 103b.
the first and second operating means 101 based on
a, 101b when the timing signal is input
Judging means 104 for judging whether or not the operation state has changed
When the determination means 104 determines that none of the operation means has changed its operation state, the reference rotation speed command value Ni is output, and the operation state of any of the operation means is
When it is determined that the detection means 102a, 1
Switching means 105 for outputting a rotation number command value of the operation means determined to have changed in the operation state among the rotation number command values Na and Nb detected at 02b, and a rotation number command value from this switching means 105 And control means 106 for controlling the engine speed so that (2) According to a second aspect of the present invention, the control device outputs a timing signal in response to power-on. (3) According to a third aspect of the present invention, the control device outputs a timing signal in response to starting of the engine. (4) The control device according to claim 4 has a manual switch that outputs a timing signal by operation. (5) The determining means 104 according to claim 5 includes the detecting means 102
a, Nb detected in steps 102a, 102b and the command values Nai, N stored in storage means 103a, 103b.
the first and second operating means 101 based on
a, change amount of command value ΔN of engine speed by 101b
a and ΔNb, respectively, and the absolute values of the command value change amounts ΔNa and ΔNb calculated by the first and second calculation means, respectively, are used as reference command value change amounts. ΔNr and first and second comparing means 104c and 104d, respectively.
When the absolute value of the command value change amount is equal to or less than the reference command value change amount, any operating means determines that the operation state has not changed, and the absolute value of the command value change amount exceeds the reference command value change amount. When there is, it is configured to determine that the operation state of the corresponding operation means has changed . (6) The switching means 105 according to claim 6 includes the first and second switching means.
Operating state of both operating means 101a and 101b change
When it is determined that the detecting means 102a, 10
It has a maximum value selecting means 105a for selecting and outputting the larger one of the rotational speed command values detected in 2b.

[0010]

(1) At least detecting means 102a, 102b
Command values Na and Nb detected by the storage means 103a and 1
Based on the command values Nai and Nbi stored in the register 03b, the determining unit 104 determines whether the operating states of the first and second operating units 101a and 101b have changed . If it is determined that none of the operation means has changed its operation state, the reference rotation number command value Ni is output, and it is determined that the operation state of any of the operation means has changed. In this case, among the rotational speed command values detected by the detecting means 102a and 102b, the rotational speed command value of the operating means for which it is determined that the operating state has changed is output from the switching means 105. The engine speed is controlled so as to be the engine speed command value. Therefore, if the operating state of any of the operation means does not change , the engine speed is controlled to the reference speed which is a relatively low speed. The operation status of one of the operation
Is turned into which a tree, the engine rotational speed is controlled such that the rotational speed corresponding to the operation amount. (2) When the timing signal is output at the time of starting the engine as in the control device according to the third aspect, the engine is reliably started at the reference rotation speed Ni, which is a low rotation speed, at the time of starting the engine. (3) When the timing signal is output by operating the manual switch as in claim 4, the engine that has been rotating at a rotational speed corresponding to the operation amount of any of the operating means until then is reset to the reference rotational speed Ni. Is done. (4) In the control device according to the fifth aspect, the difference between the rotation speed command value determined by the operation amount at the time of outputting the timing signal and the rotation speed command value determined by the operation amount detected by the detection unit is a reference change amount. A change in the operation state is determined depending on whether the value is larger or smaller than the command value. (5) In the control device according to claim 6, when a plurality of rotation speed command values are input, the maximum value is selected to control the engine rotation speed.

[0011]

FIG. 2 shows a case where the present invention is applied to an engine speed control device of a diesel engine having a governor mechanism. In this embodiment, an accelerator lever 1A, an accelerator pedal 1B, and an accelerator grip 1C are provided as accelerator operation members, and the governor operation amount is controlled based on the operation amount of each accelerator operation member to control the engine speed.

The accelerator lever 1A is provided on a side stand in the driver's seat and includes a well-known lever mechanism and a potentiometer 1a for detecting a lever operation amount and outputting a rotation speed command signal (rotation speed command value) Na. The mechanism is configured to be rotatable in the vehicle longitudinal direction. The accelerator lever 1A can be fixed at a predetermined rotation position, and the engine speed can be set to an arbitrary value. The accelerator pedal 1B is provided on the floor of the driver's seat, and has a lever mechanism provided with a well-known foot pedal at the tip thereof, and a potentiometer 1b that detects a pedal depression amount and outputs a rotation speed command signal (rotation speed command value) Nb. It is composed of The foot pedal is constantly biased and held at an initial position by a spring, and the engine speed is set to a desired idle speed at the initial position. The accelerator grip 1C is, for example, rotatably provided on the grip of the turning operation lever SL, and includes a well-known rotation mechanism and a potentiometer 1c that detects the amount of rotation and outputs a rotation speed command signal (rotation speed command value) Nc. Thus, even when the foot brake is used, the engine speed can be controlled without releasing the hand from the turning lever.

Reference numerals 2a, 2b, and 2c denote storage units, each of which operates in response to an input timing signal.
Rotational speed command values Nai, Nb corresponding to the operation amounts of the accelerator operation members output from potentiometers 1a to 1c constituting the accelerator pedal 1B and the accelerator grip 1C.
i and Nci are respectively stored. The timing signal is output, for example, when the power switch is turned on. 3a,
Reference numerals 3b and 3c denote addition points, which are output from the rotational speed command values Nai, Nbi, and Nci stored in the storages 2a to 2c, and the potentiometers 1a to 1c of the accelerator lever 1A, the accelerator pedal 1B, and the accelerator grip 1C. Speed command values Na, N corresponding to those manipulated variables
b, Nc and the differences ΔNa, ΔNb, ΔNc are calculated and output.

4 is a first accelerator operation amount setting device,
For example, a first reference value ΔNr of about 50 rpm is set in advance. Reference numerals 5a, 5b, and 5c denote comparators, which respectively output difference signals ΔNa, ΔNb, ΔNc from the addition points 3a to 3c and the first signals.
The reference value ΔN set in the accelerator operation amount setting device 4
r (for example, 50 rpm), and outputs a high-level signal when the difference signal is equal to or greater than the reference value.
The contacts b and 6c are switched to the b side. When the difference signal is less than the reference value, a low level signal is output, and the switches 6a,
The contacts 6b and 6c are switched to the a side. Reference numeral 7 denotes a second accelerator operation amount setting device, for example, an idle rotation speed Ni of about 1300 rpm is preset as a second reference value. The second accelerator operation amount setting device 7 has a switch 6a.
Switches 6a to 6c are set respectively by the second reference value Ni or the accelerator lever 1A, the accelerator pedal 1B, and the accelerator grip 1C based on the comparison results of the comparators 5a to 5c. The rotation speeds Na, Nb, and Nc are output. Reference numeral 8 denotes a maximum value selection circuit that selects the maximum value among the rotation speed command values output from the switches 6a to 6c.

Reference numeral 9 denotes a motor drive control circuit which controls the rotation speed command value selected by the maximum value selection circuit 8 and the governor lever 1.
1 and a detection signal from the sensor 12 for detecting the amount of rotation of the motor 1, and the governor motor 1 in the subsequent stage until the two signals become equal.
A drive signal is output to 0.

The operation of the thus configured rotation speed control device will be described. When the power switch is turned on, a timing signal is input to the storage units 2a to 2c. At that time, rotation speed command values Na, Nb, and Nc corresponding to the operation amounts of the accelerator lever 1A, the accelerator pedal 1B, and the accelerator grip 1C are respectively obtained. Initial values Nai, Nbi,
It is stored as Nci. When none of the accelerator lever 1A, the accelerator pedal 1B, and the accelerator grip 1C is operated after the power switch is turned on, the outputs of the addition points 3a to 3c are zero, and the first reference value ΔNr is larger than the addition point output. Each output of the switches 5a to 5c keeps a low level, and switches the switches 6a to 6c to the contact a side.
Therefore, since each of the switches 6a to 6c outputs the second reference value Ni, the maximum value selection circuit 8 also outputs the second reference value Ni, and the engine speed becomes the second reference value, that is, the idle speed. It is set to the number Ni.

After turning on the power switch, the accelerator lever 1
When any one of A, accelerator pedal 1B, and accelerator grip 1C is operated by a predetermined amount or more (first reference value or more), the output of the corresponding one of comparators 5a to 5c becomes high level, and switch 6a 6c is switched to the contact b side. Accelerator lever 1
A, the output of the comparator corresponding to one of the accelerator pedal 1B and the accelerator grip 1C whose operation is less than a predetermined amount is maintained at a low level, and the corresponding switch is switched to the contact a side. Therefore, when any one of the switches is switched to the contact b, the output from the contact b is selected by the maximum value selection circuit 8, and when a plurality of switches are switched to the contact b, each of the contacts b The maximum output among the outputs from is selected by the maximum value selection circuit 8, and the governor lever of the governor 11 is controlled by the motor 10 so that the engine speed becomes the selected speed command value.

According to such a rotational speed control device, even if the engine is started while any one of the accelerator lever 1A, the accelerator pedal 1B, and the accelerator grip 1C is operated, the outputs of the addition points 3a to 3c are maintained. Since all of them are zero, the comparators 5a to 5c hold the low level, and the switches 6a to 6c output the second reference value, so that the engine is started at the idle speed. Further, even when the accelerator pedal 1b is restrained at a predetermined position and does not completely return to the initial position when the engine is started, the engine speed can be controlled to be equal to or lower than the speed determined by the restrained position of the accelerator pedal 1b.

In the correspondence between the above embodiment and the claims, the accelerator lever 1A and the accelerator pedal 1B correspond to the first and second operating means 101a and 101b, respectively, and the potentiometers 1a and 1b correspond to the first and second actuators, respectively. Detecting means 102a and 102b are stored in storage devices 2a and 2b, respectively, as first and second storage means 103a and 103b.
, The addition points 3a and 3b constitute first and second calculation means, respectively, and the comparators 5a and 5b constitute comparison means, respectively. The addition points 3a and 3b, the comparators 5a and 5b, etc., determine the determination means 104, and the switches 6a, 6b determine the switching means
The motor drive circuit 9 and the governor motor 10 constitute control means 106 in FIG.

The configuration of the above embodiment can be modified as follows. (1) The number of accelerators is not limited to three, but may be two or four or more. For example, the accelerator pedals for the right foot and the left foot may be provided independently. (2) The present invention can also be applied to an engine speed control device in which an up / down switch is provided instead of the accelerator bar, and the engine speed is controlled so that the target speed set by the switch is attained. (3) The detector of the accelerator operation amount is not limited to the potentiometer, and a differential transformer type detector may be used. (4) Although the rotation speed command value corresponding to the operation amount of each accelerator is stored in the storage device in response to the power-on, it is also possible to use an engine start signal or a signal output by operating a dedicated manual switch. Good. When the manual switch signal is also used, all the accelerators can be temporarily disabled during the engine speed control, and the engine speed can be forcibly set to the second reference value. (4) A stepping motor or various types of fluid-type or solenoid-type cylinders may be used as the governor lever drive actuator.

[0021]

As described above, according to the present invention, the first and second engine speed setting for inputting the timing signal are performed.
The change in the operation state of the first and second operation means is determined by comparing the operation amount of the second operation means with the current operation amount, and the operation state of each operation means has changed. and when it is determined, so as to control the engine speed so that the engine revolution speed corresponding to the operation of the the determined operating means operating state has changed, the change in the operation state of the operation means <br When /> is not determined, the engine speed is controlled to a preset relatively low speed, so that, for example, the engine can always be started at a low speed when the engine is started.

[Brief description of the drawings]

[Fig. 1] Claim correspondence diagram

FIG. 2 is a block diagram showing an example of an engine speed control device according to the present invention.

[Explanation of symbols]

 Reference Signs List 1A Accelerator lever 1B Accelerator pedal 1C Accelerator grip 1a-1c Potentiometer 2a-2c Storage 3a-3c Addition point 4 First accelerator operation amount setting device 5a-5c Comparator 6a-6c Switch 7 Second accelerator operation amount setting device 8 Maximum value selection circuit 9 Motor drive control circuit 10 Governor motor 11 Governor 12 Governor lever operation amount detector 101a First operation means 101b Second operation means 102a, 102b Detection means 103a, 103b Storage means 104 Judgment means 105 Switching means 106 Control means

Claims (6)

(57) [Claims] A first operating member capable of instructing an arbitrary engine speed according to an operation amount and maintaining the engine speed even when the operating force is released, and an arbitrary engine according to the operation amount An engine for instructing the engine speed and returning to a predetermined engine speed when the operating force is released, the engine controlling the engine speed based on the engine speed command from each operating member A rotation speed control device, wherein first and second detection means for detecting command values of an engine rotation speed by the first and second operation members, respectively; and the first and second detection units in response to a timing signal input. First and second storage means for respectively storing a command value of the engine speed by the operating member, and at least a command value detected by the detection means and a command stored in the storage means. Based on the door, the first contact
And the operation state of the second operation means is the timing signal input.
A determination unit configured to determine whether changes from the operating state at the time of force, none of the operating means by the judging means that the operation state
Outputs the reference rotation speed command value when it is determined not to change, when the operation state of any of the operation means is determine <br/> constant and the changes are detected by the detection means Switching means for outputting a rotation speed command value of the operating means determined to have changed the operation state among the rotation speed command values; and control for controlling the engine speed so that the rotation speed command value from the switching means is obtained. Means for controlling the engine speed. 2. The engine speed control device according to claim 1, wherein said timing signal is output in response to power-on. 3. The control device according to claim 1, wherein the timing signal is output in response to starting of the engine. 4. The engine speed control device according to claim 1, further comprising a manual switch for outputting the timing signal when operated. 5. The control device according to claim 1, wherein the determination unit determines the first and second values based on a command value detected by the detection unit and a command value stored in the storage unit. First and second calculating means for calculating a command value change amount of the engine speed by the operating means, respectively, and a reference command value based on the absolute value of the command value change amount calculated by the first and second calculating means, respectively. First and second comparing means for respectively comparing the change amount with the change amount, and when the absolute value of the command value change amount is equal to or less than the reference command value change amount, none of the operation means has changed its operation state. When the absolute value of the command value change amount exceeds the reference command value change amount, the operation state of the corresponding operating means changes.
Engine speed control apparatus characterized by determining a phased. 6. The control device according to claim 1, wherein
Said switching means, Misao of the first and second operating means
When it is determined that both of the working states are changing, a maximum value selecting means for selecting and outputting the larger one of the rotational speed command values detected by the detecting means is characterized in that it is provided. Engine speed control device.