JPH0932596A - Prime mover control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent operation of a prime mover in specific rotating speed areas where a noise and a vibration level are large, and enhance dwelling performance and durability or the like of a vehicle by judging whether or not rotating speed of the prime mover exists in the specific rotating speed areas, and outputting a preset constant driving signal to an electric motor when it is judged as Yes. SOLUTION: In the case of controlling rotating speed of a diesel engine in a construction machine such as a hydraulic shovel, first of all, engine rotating speed N is read in from a crank angle sensor 22. When constant time passes after a timer is started, whether or not the engine rotating speed N is changed over, for example, 10 to 50rpm during that time is judged. Here, when it is judged as Yes, whether or not the engine rotating speed N is in specific rotating speed areas N1, N2 and N3 is judged, and when it is judged as Yes, a driving pulse signal having a constant pulse is outputted to a stepping motor 6, and a governor lever of a governor is rotated in the speed increasing direction or the speed reducing direction by the stepping motor 6, and operation in the specific rotating speed areas is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prime mover control device provided in a construction machine such as a hydraulic excavator and suitable for controlling the rotation speed of a prime mover.

[0002]

2. Description of the Related Art Generally, a construction machine is equipped with a diesel engine as a prime mover, and the diesel engine drives a hydraulic pump or the like serving as a hydraulic source.

Therefore, the conventional construction machine is provided with a control lever such as a throttle lever in a driver's cab, and when a driver or the like tilts the control lever, the operation force at this time is transmitted through a control cable, a link rod or the like. The engine speed is controlled through the governor of the engine. However, in the case of mechanically connecting the control lever and the governor of the engine with a control cable, a link rod, or the like, there is a disadvantage that a large operating force is required due to a large mechanical resistance.

In order to improve such drawbacks and to remotely control the governor of the engine electrically, an electric motor for driving the governor lever of the governor is provided near the engine, and a fuel lever or an up / down switch is provided in the operator's cab. And a controller such as a microcomputer. The controller outputs a drive signal to the electric motor based on the command signal from the rotation speed command means, and the governor lever of the governor is electrically driven by open loop control. It is known to rotate by a motor.

Therefore, referring to FIGS. 3 and 4, an example in which a motor control device of this type according to the prior art is used in a construction machine will be described.

In the drawings, 1 is a diesel engine (hereinafter referred to as "engine") mounted as a prime mover on a construction machine, 2 is a governor provided in the engine 1,
The governor 2 includes a governor lever 3 and the governor lever 3
The target rotation speed and the actual rotation speed of the engine 1 are increased or decreased by rotating the engine 1 in the acceleration H direction or the deceleration L direction. The output shaft of the engine 1 is provided with a hydraulic pump (not shown) or the like serving as a hydraulic source, and by discharging pressure oil from the hydraulic pump, a hydraulic actuator such as a hydraulic cylinder or hydraulic motor (see FIG. (Not shown) is driven.

Further, the governor 2 is provided with stoppers 4A, 4B for restricting the turning range of the governor lever 3, and the governor lever 3 is constantly urged toward the stopper 4A by a spring 5 as an urging means. Then, when the governor lever 3 contacts the stopper 4A, the governor 2
Sets the rotation speed of the engine 1 to the minimum rotation speed (idle rotation speed or zero), and sets the rotation speed of the engine 1 to the maximum rotation speed (full rotation speed) when the governor lever 3 contacts the stopper 4B.

Reference numeral 6 denotes a stepping motor as an electric motor for rotating the governor lever 3 of the governor 2. A rotating lever 6A is attached to the output shaft of the stepping motor 6, and the rotating lever 6A is connected via a link 7. And is connected to the governor lever 3. Then, the stepping motor 6 is rotated forward or backward by the output of a drive pulse signal from the controller 9 described later, and the governor lever 3 is rotated via the link 7 in the speed-up H and speed-down L directions.

Reference numeral 8 denotes a command device provided in a driver's cab of the construction machine and serving as a rotation speed command means for commanding a target rotation speed of the engine 1. The command device 8 is constituted by a fuel lever, a dial, an up / down switch or the like. Then, the driver or the like manually outputs a command signal corresponding to the operation amount to the controller 9.

Reference numeral 9 denotes a controller which is provided in a driver's cab or the like, and which is constituted by a microcomputer or the like. The controller 9 inputs to the input unit 10 an input signal to which a command signal from the command device 8 is input. The target rotation speed of the engine 1 is calculated based on the command signal thus generated, and the drive pulse signal output from the output unit 11 and the operation unit 12 that causes the output unit 11 to output the drive pulse signal to the stepping motor 6 The counter 13 as a monitor means for counting the number of pulses and outputting the counted value to the arithmetic unit 12.

Here, the arithmetic unit 12 of the controller 9
Causes the output unit 11 to output a drive pulse signal until the count value of the counter 13 reaches a value corresponding to the target rotation speed. Then, the arithmetic unit 12 of the controller 9 outputs the output unit 1
1 constitutes drive signal output means, and the stepping motor 6 is rotated by the drive pulse signal, so that the rotation speed of the engine 1 is controlled to the target rotation speed.

The motor control device according to the prior art has the above-mentioned configuration. For example, when a driver or the like outputs a desired rotation speed command from the command device 8 to the controller 9, the arithmetic unit 12 of the controller 9 causes the command device to operate. The target rotation speed of the engine 1 is calculated on the basis of the command signal from 8, and the drive pulse signal is output from the output unit 11 until the count value of the counter 13 reaches a value corresponding to the target rotation speed.

The stepping motor 6 is normally and reversely rotated by the drive pulse signal at this time, so that the rotating lever 6A and the governor lever 3 are rotated in the speed increasing H and decelerating L directions to rotate the engine 1. The open loop control is performed so that the number becomes the target rotation speed corresponding to the command signal.

Here, it is known that the relationship between the actual speed of the engine 1 (engine speed N) and the output torque T generally changes along the characteristic line 14 shown in FIG.
The characteristic line portions 14a, 14b, etc., which are part of the characteristic line 14,
The change characteristic of the engine speed N when the target speed of the engine 1 is made constant is shown.

That is, when the target rotation speed of the engine 1 is set, for example, on the characteristic line portion 14a by the command signal from the command device 8, the engine rotation speed N depends on the load state (output torque T) of the engine 1. It changes along the characteristic line portion 14a, and the engine speed N becomes the actual speed Na1 during the load operation of the engine 1 (the operation of the hydraulic actuator), and the engine speed during the no-load operation of the engine 1 (the hydraulic actuator is stopped). The number N increases up to the actual rotation number Na2, for example, about 100 rpm.

Further, when the target rotation speed of the engine 1 is set on the characteristic line portion 14b by the command signal from the command device 8, the engine rotation speed N shows the characteristic line according to the load state (output torque T) of the engine 1. Changes along section 14b,
During load operation of the engine 1 (actuation of the hydraulic actuator), the engine speed N becomes the actual speed Nb1, and during no-load operation of the engine 1 (stop of the hydraulic actuator), the engine speed N reaches the actual speed Nb2. Increase by about 100 rpm.

[0017]

By the way, in the above-mentioned conventional technique, when the engine 1 is mounted on a construction machine such as a hydraulic excavator, the noise and vibration level of the construction machine are inspected, and the engine 1 is driven. Vibrations, intake and exhaust noises, vibrations from cooling fans, pulsations of hydraulic pumps directly connected to the output shaft of engine 1, resulting vibrations of hydraulic piping (abnormal noises), and resonance or resonance on the vehicle body side due to these However, there is a problem in that the habitability in the driver's cab, the durability of the construction machine, the service life, etc. are adversely affected.

Therefore, the inventors of the present invention have determined at which engine speed N (specific speed range) the resonance, the resonance, etc. occur in the entire normal speed range in the operating state of the engine 1. As a result of earnest research including the stages of design and trial manufacture, a plurality of specific rotation speed ranges (including a rotation speed range of about 5 to 8 rpm before and after the specific rotation speed) where the resonance and the resonance are likely to occur are found. , For example, the specific rotation speed range N shown in FIG.
1, N2, N3, etc., and these specific speed range N
The inventors reached the present invention by finding that the vibration levels of 1, N2 and N3 exceed the reference value R0 in a peak form.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can surely prevent the prime mover from operating in a specific rotation speed range where noise and vibration levels are high, and the vehicle or the like at the time of operation can be prevented. It is an object of the present invention to provide a prime mover control device capable of eliminating the resonance and the resonance phenomenon and effectively improving the habitability and durability of the vehicle.

[0020]

In order to solve the above-mentioned problems, the present invention provides a prime mover, a governor attached to the prime mover, for increasing or decreasing the number of revolutions of the prime mover according to a turning angle of a governor lever, An electric motor for rotating a governor lever of a governor, a rotation speed command means for commanding a rotation speed of the prime mover, and a drive signal output means for outputting a drive signal to the electric motor based on a command signal from the rotation speed command means. It is applied to the prime mover control device.

The features of the configuration adopted by the invention of claim 1 are the number of revolutions detecting means for detecting the number of revolutions of the prime mover, and the number of revolutions for storing a predetermined specific number of revolutions range of the prime mover. Range storage means, rotation speed determination means for determining whether or not the rotation speed of the prime mover detected by the rotation speed detection means is within a specific rotation speed range stored by the rotation speed range storage means, and the rotation speed And a constant drive signal output means for outputting a predetermined constant drive signal to the electric motor when the determining means determines that the rotational speed of the prime mover is within a specific rotational speed range.

In the invention according to claim 2, the specific rotation speed range stored by the rotation speed range storage means is a specific rotation speed range in a small range in which vibration generated during the operation of the prime mover sharply increases. The constant drive signal output means outputs a preset constant pulse drive signal to the electric motor so that the rotation speed of the prime mover falls outside the range of the specific rotation speed range.

Further, in the invention described in claim 3, there is provided a rotation speed fluctuation judging means for judging whether or not the rotation speed of the prime mover is in the middle of fluctuation based on a detection signal from the rotation speed detecting means, When the rotational speed variation determining means determines that the rotational speed of the prime mover is in the process of changing, the determination operation by the rotational speed determining means is interrupted.

[0024]

According to the first aspect of the present invention, the rotation speed of the prime mover detected by the rotation speed detecting means is stored by storing the predetermined rotation speed range of the prime mover determined in advance by the rotation speed range storing means. Whether or not it is within this specific rotational speed range can be determined by the rotational speed determination means, and when the rotational speed determination means determines that the rotational speed of the prime mover is within the specific rotational speed range, it is preset by the constant drive signal output means. By outputting a constant drive signal to the electric motor, it is possible to automatically change the rotation speed of the prime mover to a rotation speed higher or lower than the specific rotation speed range.

According to a second aspect of the present invention, a specific rotation speed range of a small range in which vibration generated during the operation of the prime mover sharply increases is stored in the rotation speed range storage means, and the prime mover is stored. By outputting a predetermined constant pulse drive signal from the constant drive signal output means to the electric motor so that the rotation speed of the motor is out of the range of the specific rotation speed range, the rotation speed of the prime mover is temporarily changed to the specific rotation speed. When the range is reached, the rotational speed of the prime mover can be automatically increased or decreased by a constant pulse drive signal (e.g., about 10 rpm), and the rotational speed of the prime mover can be changed outside the specific rotational speed range.

Further, as in the invention described in claim 3,
By including a rotation speed fluctuation determining unit that determines whether or not the rotation speed of the prime mover is changing based on a detection signal from the rotation speed detecting unit, when the rotation speed of the prime mover is changing, It is possible to interrupt the determination operation by the rotation speed determination means, and it is possible to prevent an extra drive signal from being output from the constant drive signal output means to the electric motor while the rotation speed is changing.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the conventional technique shown in FIGS. 3 to 5 are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 21 is a start switch for the engine 1, 22 is a crank angle sensor as a rotation speed detecting means for detecting the actual rotation speed of the engine 1, and the crank angle sensor 22 is a crank shaft (not shown). By detecting the rotation of the engine, a signal corresponding to the engine rotation speed N (actual rotation speed) is output to the controller 23 described later.

Reference numeral 23 denotes a controller composed of a microcomputer or the like, the input side of which is connected to the starting switch 21, the crank angle sensor 22, the command device 8 and the like, and the output side is connected to the stepping motor 6 and the like. There is. And the controller 2
In addition to having the same function as the controller 9 described in the prior art, the storage circuit 3 stores the program and the like shown in FIG. .

Further, in the memory circuit of the controller 23, in the memory area 23A thereof, the specific rotation speed ranges N1, N2, N3 in which the vibration level and the like illustrated in FIG.
Etc. are stored so that they can be updated, and a timer t and a fixed time t0 (for example, about 0.1 to 0.5 seconds) are stored. The storage area 23A of the controller 23 constitutes a rotation speed range storage means.

The prime mover control device according to the present embodiment has the above-mentioned configuration, and its basic operation is not particularly different from that of the prior art.

Therefore, the rotational speed change control processing of the engine 1 by the controller 23, which is a feature of this embodiment, will be described with reference to FIG.

First, when the processing operation is started, in step 1, the engine 1 is operated based on the signal from the start switch 21.
If it is determined to be "YES", the process moves to step 2 to start the timer t, and in step 3, the engine speed N at this time is read from the crank angle sensor 22.

Next, at step 3, a fixed time t0 (for example, about 0.1 to 0.5 seconds) has elapsed since the timer t was started.
Is determined, and while the determination is "NO", the process returns to step 3 to continue reading the engine speed N.
Then, if "YES" is determined in step 4, the process proceeds to step 5, and in step 5, whether the engine speed N fluctuates (increases or decreases) over 10 to 50 rpm or more during the elapse of the constant time t0. Determine whether or not.

When it is judged "YES" in step 5, for example, the characteristic line portion 1 of the characteristic line 14 shown in FIG.
4a, 14b, etc., the target rotation speed of the engine 1 by the command device 8 is a commanded constant value, but the engine 1
Engine speed N according to the load condition (output torque T) of
Can be determined to have changed along the characteristic line portions 14a, 14b, etc., so that the process returns to step 2 and the subsequent processing is repeated.

When it is judged "YES" in step 5, for example, a fixed time t0 of about 0.1 to 0.5 seconds.
Since the engine speed N is substantially constant during the period, the process proceeds to step 6 and it is determined whether the engine speed N at this time is within the specific speed range N1, N2, N3. If it is determined to be "NO", it means that the engine speed is outside the specific engine speed range N1, N2, N3. Therefore, the process returns to step 8 and the target engine speed control of the engine 1 by the command device 8 is continued.

Next, when "YES" is determined in step 5, the engine speed N is in the specific speed range N1, N2.
, N3, and the vibration level of the vehicle equipped with the engine 1 may greatly exceed the reference value R0 shown in FIG. 5, so the routine proceeds to step 7, where a constant pulse (for example, about 1 to 3 pulses) is applied to the stepping motor 6. 3 is output, and the governor lever 3 shown in FIG. 3 is rotated by the stepping motor 6 in the speed-increasing H direction or the speed-decelerating L direction, thereby increasing or decreasing the engine speed N by about 10 rpm, for example.

After that, by repeating the processes from step 1 onward, the engine speed N is kept within the specific speed range N1, N2 for a certain time t0 (for example, about 0.1 to 0.5 seconds) or more. The rotation speed changing control is continued so as to avoid staying within N3, and the vibration level of the vehicle equipped with the engine 1 is prevented from increasing beyond the reference value R0.

Thus, according to the present embodiment, the engine speed N, which is the actual speed of the engine 1, is read from the crank angle sensor 22, and this engine speed N is maintained for a certain time t0.
Specific rotation speed range N during (for example, about 0.1 to 0.5 seconds)
While determining whether the engine speed is within 1, N2 and N3, if the determination result is "YES", the engine speed N at this time is N.
Is changed by, for example, about 10 rpm (acceleration or deceleration)
Because of the configuration, it is possible to immediately avoid (change) that the engine 1 is operated in the specific rotation speed range N1, N2, N3 where the noise and vibration levels are large, and resonance or resonance phenomenon occurs in the vehicle equipped with the engine 1. Can be reliably prevented.

In the processing from step 2 to step 5, the engine speed N is, for example, 10 during the constant time t0 based on the detection signal from the crank angle sensor 22.
It is determined whether or not there is a change (increase or decrease) over 50 rpm or more, and when the change is in progress, the characteristic line 14 illustrated in FIG.
It is assumed that the engine speed N is changing according to the load state (output torque T) of the engine 1 as in the characteristic line portions 14a and 14b of FIG. Therefore, the target rotation speed control of the engine 1 by the command device 8 can be continued, and the rotation speed control of the engine 1 can be stably performed.

Therefore, according to this embodiment, it is possible to reliably prevent the engine 1 from operating within the specific rotational speed range N1, N2, N3 where the noise, vibration level, etc. are large, and to operate (operate) the engine 1. It is possible to effectively avoid the resonance and the resonance phenomenon of the vehicle at the time, and to significantly improve the comfortability and the durability of the vehicle.

In the above embodiment, step 5 of the program shown in FIG. 2 shows a specific example of the rotational speed fluctuation judging means which is a constituent feature of the present invention, and step 6 shows a specific example of the rotational speed judging means. The step 7 shows a specific example of the constant drive signal output means.

Further, in the above-described embodiment, the vibration level as shown in FIG. 5 is set as a plurality of specific rotation speed regions in which the resonance or the resonance is likely to occur in the entire normal rotation speed region in the operating state of the engine 1. Specific speed range N exceeding the reference value R0
1, N2, and N3 have been described as an example, but the present invention is not limited to this and, for example, depending on the size and type of the vehicle in which the engine 1 is mounted, these specific rotation speed ranges N
Since 1, N2, and N3 change, it may be obtained from experimental data for each vehicle. Depending on the type of vehicle, resonance or resonance may easily occur in a specific rotation speed range (before a specific rotation speed, (Including a rotation speed range of 5-8 rpm later)
Is a single specific rotational speed range (for example, specific rotational speed range N1, N
2 or N3), and the vibration level may exceed the reference value R0 in a peak state in a specific rotational speed range of 2 or 4 or more.

Further, in each of the above-mentioned embodiments, the stepping motor 6 is driven positively by the drive pulse signal from the controller 9.
Although it has been described that the rotation speed of the engine 1 is controlled by the open loop control by performing the reverse rotation, the present invention is not limited to this, and for example, a rotation of a potentiometer or the like for detecting the rotation angle of the rotation lever 6A. A dynamic angle detecting means may be separately provided, and the rotation speed of the engine 1 may be feedback-controlled based on the detection signal from the rotation angle detector.

[0045]

As described in detail above, according to the first aspect of the present invention, the rotational speed detecting means is stored by storing the predetermined specific rotational speed area of the prime mover in the rotational speed area storing means. When the number of revolutions of the prime mover detected in step 1 is determined by the number-of-rotations determination means, the number-of-rotations determination means determines that the number of revolutions of the prime mover is within the particular number of revolutions, Since the drive signal output means is configured to output a preset drive signal to the electric motor,
The number of revolutions of the prime mover can be automatically changed to a higher number of revolutions or a lower number of revolutions than the particular number of revolutions, for example, to ensure that the prime mover is operated in a particular number of revolutions with a high noise or vibration level. In addition to the prevention, resonance and resonance phenomenon of the vehicle and the like during driving can be eliminated, and habitability and durability of the vehicle and the like can be surely improved.

According to a second aspect of the present invention, a specific rotation speed range of a small range in which vibration generated during operation of the prime mover sharply increases is stored in the rotation speed range storage means, and the prime mover is stored. By outputting a predetermined constant pulse drive signal from the constant drive signal output means to the electric motor so that the rotation speed of the motor is out of the range of the specific rotation speed range, the rotation speed of the prime mover is temporarily changed to the specific rotation speed. When the range is reached, the number of revolutions of the prime mover can be automatically increased or decreased by a fixed pulse drive signal (equivalent to about 10 rpm, for example) to change the number of revolutions of the prime mover outside the specified number of revolutions range. It is possible to effectively reduce noise and vibration of a running vehicle or the like.

Further, as in the invention described in claim 3,
By including a rotation speed fluctuation determining unit that determines whether or not the rotation speed of the prime mover is changing based on a detection signal from the rotation speed detecting unit, when the rotation speed of the prime mover is changing, The determination operation by the rotation speed determination means can be interrupted, the control of the target rotation speed based on the command signal from the rotation speed command means can be continued, and the rotation speed control of the prime mover can be performed stably.

[Brief description of drawings]

FIG. 1 is a control block diagram showing a prime mover control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an engine speed change control process.

FIG. 3 is an overall configuration diagram showing a motor control device according to a conventional technique.

FIG. 4 is a characteristic diagram showing a relationship between engine speed and output torque of the engine.

FIG. 5 is a characteristic diagram showing a relationship between engine speed and vibration level.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 engine (motor) 2 governor 3 governor lever 4A, 4B stopper 6 stepping motor (electric motor) 7 link 8 command device (rotation speed command means) 21 start switch 22 crank angle sensor (rotation speed detection means) 23 controller (drive signal output) Means) 23A storage area (rotation speed range storage means) N1, N2, N3 specific rotation speed range

Claims (3)

[Claims] 1. A prime mover, a governor attached to the prime mover, for increasing or decreasing the number of revolutions of the prime mover according to a rotation angle of the governor lever, an electric motor for rotating the governor lever of the governor, and a number of revolutions of the prime mover. In a prime mover control device comprising: a rotation speed command means for instructing a rotation speed command means; and a drive signal output means for outputting a drive signal to the electric motor based on a command signal from the rotation speed command means. Number detection means, rotation speed range storage means for storing a predetermined specific rotation speed range of the prime mover, and rotation speed of the prime mover detected by the rotation speed detection means are stored in the rotation speed range storage means. A rotation speed determination means for determining whether or not the rotation speed is within a specific rotation speed range, and a preset value when the rotation speed of the prime mover is determined to be within the specific rotation speed range by the rotation speed determination means. Engine control apparatus characterized by a drive signal is configured to include a constant drive signal output means for outputting to said electric motor. 2. The specific rotational speed range stored in the rotational speed range storage means is a specific rotational speed range in a small range in which vibration generated during the operation of the prime mover sharply increases, and the constant drive signal output means 2. The prime mover control device according to claim 1, wherein a drive signal having a preset constant pulse is output to the electric motor so as to remove the revolution speed of the prime mover from the range of the specific revolution range. 3. A rotation speed variation determining means for determining whether or not the rotation speed of the prime mover is in the middle of variation based on a detection signal from the rotation speed detecting means, and the rotation speed variation determining means controls the rotation speed of the prime mover. The prime mover control device according to claim 1 or 2, wherein, when it is determined that the rotation speed is being changed, the determination operation by the rotation speed determination means is interrupted.