JPS63105250A - Engine speed control device for digging work machine - Google Patents

Abstract

PURPOSE:To enable the cost to be cheap reduced providing a less number of sensors for detection, by detecting a bucket for whether or not it is in moving so that work is decided to be stopped. CONSTITUTION:A sensor 7, provided in a bucket, detects the bucket to be moved or stopped, outputting a signal of moving or stopping to a controller 18. A control means 17 is switched to a position, in which the control means 17 intervenes in the action of an engine control device by an output signal from the controller 18 based on a stop signal of the bucket controlling an instruction engine speed so as to be in a low speed, and to a position in which the control means 17 intervenes not in the action of the engine control device by an output signal from the controller 18 based on a moving signal of the bucket. In this way, stoppage of work can be decided by detecting whether or not the bucket is in moving through the sensor 7, accordingly, the necessity for providing a sensor, for detecting whether or not a control lever is placed in the neutral position, in all the control levers is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine rotation speed control device for excavating machines such as hydraulic excavators and wheel loaders.

(Prior art) For example, Japanese Patent Publication No. 60-38561 discloses a device for controlling the engine rotation speed to a low rotation speed during short breaks in work in order to save fuel in excavation machines. It is being

In this conventional device, when all operating levers are in the neutral position, it is determined that the work is in a short rest state, and after this all-lever neutral state has elapsed for a preset delay time, the engine speed is reduced to a low speed. It was reduced to a number.

However, according to this conventional device, it is necessary to use sensors to detect whether or not all operating levers are in the neutral position, which requires a large number of expensive sensors. For example, in the case of a hydraulic excavator, when mechanically detecting the lever position, there is a Twelve sensors are required. Alternatively, in a machine that uses a hydraulic remote control system, in the case of a system that detects remote control pressure, if high pressure selection is performed downstream of a pair of remote control valves, a total of six sensors (pressure sensors) are required. This has resulted in high costs. In addition, when using a mechanical detection method for existing machines, it becomes troublesome to incorporate the sensor due to space constraints, and when using a remote control pressure detection method,
There is a problem in that the entire block of the hydraulic remote control circuit must be replaced in order to incorporate the sensor.

Furthermore, when a hydraulic excavator continues to turn by inertia with the swing lever returned to neutral, so-called neutral drift,
If the turning time exceeds the above-mentioned certain delay time, the engine speed will drop, which causes a problem in that there will be a delay in the engine returning to high speed when it is desired to immediately turn in the opposite direction after the turn. .

(Objective of the Invention) Therefore, the present invention reduces the number of sensors, makes it easy to incorporate the sensors, and furthermore, the engine An object of the present invention is to provide an engine rotation speed control device for an excavation work machine that can control the rotation speed.

(Structure of the Invention) The present invention is characterized in that a work attachment including a bucket as an element is attached to an excavation work machine main body, and an engine mounted on the main body and driven by the engine. A hydraulic pump, an actuator driven by pressure oil from the hydraulic pump, an actuation control t11 device that controls the operation of the actuator, an engine rotation speed setting device that sets the rotation speed of the engine, and this engine rotation speed setting device. An excavation work machine equipped with an engine control device that commands a set engine rotation speed by operating the engine control device, a control means for controlling the operation of the engine control device, and a control means provided on the bucket of the work attachment to move or stop the bucket. and a controller that receives a bucket movement signal or a bucket 1 stop signal from the sensor and outputs a signal corresponding to the input signal to the control means, and the control means The output signal from the controller based on the Bucket 1 stop signal from the sensor intervenes in the operation of the engine control device. and an engine rotation speed control device for an excavating work machine, which is configured to be switched to a position that does not intervene in the operation of the engine control device by an output signal from a controller based on a bucket movement signal from the sensor.

(Example) In this example, a hydraulic excavator is taken as an example to which the present invention is applied. The overall configuration of this hydraulic excavator is explained in the third section.
Shown in the figure.

In FIG. 3, A is the excavator main body which can run and turn, and B is a work attachment attached to this main body 1. This working attachment B consists of a boom 1, an arm 2, a bucket 3, and cylinders 4, 5, 6 for raising and lowering the boom, for rotating the arm, and for operating the bucket. Bucket 3 in this work attachment B
A speed sensor 7 is provided at the speed sensor 7.
This causes hyperactivity of the bucket 3 in the up and down, left and right, front and back directions (
displacement) is detected. That is, the speed sensor 7 detects the independent operation of the bucket 3 (excavation, dumping), the vertical movement of the bucket 3 due to the rotation of the arm 2 or the up-and-down movement of the boom 1, and the movement of the bucket 3 due to the running or turning of the main body 1. Detected. By detecting all movements of the bucket 3 in this way, it is detected whether the hydraulic excavator is working or not working.

The speed sensor 7 uses an accelerometer or the like that uses a position detector to detect the rotation (angular displacement) of the pendulum that occurs when acceleration acts on the pendulum, and when acceleration occurs due to the movement of the bucket 3, the bucket moves. It emits a signal, and when the acceleration is gone, it emits a bucket stop signal. Further, as this sensor, any of a uniaxial sensor whose measurement direction is limited to one direction, a biaxial sensor which can measure in two directions, and a triaxial sensor which can measure in three directions can be used. If a three-axis sensor is used, only one sensor 7 needs to be installed in the bucket 3, if a two-axis sensor and a single-axis sensor are combined, two sensors 7 are required, and if only a -axis sensor is used, three sensors 7 are required. becomes. However, - uniaxial sensors are placed at 45° with respect to each of the vertical, horizontal, and front/back reference axes.
If it is attached to the bucket 3 in an inclined state, it can essentially function as a three-axis sensor, so only one sensor 7 is required.

Similarly, it is also possible to provide two -axis sensors, one of which functions as a two-axis sensor.

In this way, in this device, the bucket 3 is provided with three sensors 7 at the most and one sensor 7 at the minimum. The sensor 7 is attached to the bucket 3 at a position where it is subjected to as little impact as possible during operation (usually a position near the attachment part to the arm 2 as shown) via a mounting bracket (not shown). Further, this sensor 7 and a controller (described later) installed in the excavator main body A are connected by a cable (not shown).

Next, in FIG. 1, 8 is an engine, and 9 is an engine 8.
1o is a hydraulic pump driven by a hydraulic pump, 1o is a hydraulic motor driven by pressure oil from a hydraulic pump 9; pumps 9 and 7
The structure provided between the cutter 10 and the
This is a directional control valve as a HIn device.

Further, 12 is a governor that adjusts the fuel injection amount of the engine 8 and sets the engine speed, and 13 is an engine control device that operates this governor 12 to command the set engine speed. It is. This engine control device 13 includes a throttle lever 1
a main control section 13a that applies an operating force of 4 to the lever 12 via the rod 15 and the governor lever 16;
It consists of a stop lever 13b. This stop lever 13b is in a normal position that does not participate in the control of the governor 12! ? Pt, a stop position P3 that commands the governor 12 to set zero rotation speed, that is, stops the engine rotation, regardless of the operation of the main control unit 13a, and a low speed position IFf P2 that is an intermediate position between these positions. iP
2, the number of rotations commanded by the main control section 13a is discounted (for example, reduced by half) to be the number of rotations commanded to the vane 12. Hereinafter, this discounted engine speed will be referred to as the low speed speed.

Reference numeral 17 denotes an electromagnetic lever drive device as a control means for controlling the stop lever 13b, which includes a boxed electromagnetic coil 17.
a and a rod 17b as a movable iron core, and this rod 17b is connected to a stop lever 13b. This lever drive device 17 becomes a control device that operates the stop lever 13b to a low speed position faP2 when the electromagnetic coil 17a is excited (intervenes in the operation of the engine control device 13), and when the electromagnetic coil 17a is energized, the stop lever 13b is
3b is kept at the normal position P1 (no intervention is made in the operation of the engine control device 13), which is a non-control position. Note that the stop lever 13b is manually operated to the stop position P3.

18 is a controller, and the detection signal from the speed sensor 7 is input to this controller 18. The controller 18 outputs an activation signal to the electromagnetic coil 17a of the lever drive device 17 when the bucket stop signal is input from the sensor 7, and otherwise outputs O (when the bucket movement signal is input). Become. Therefore, the electromagnetic coil 17a is in a non-excited state while the bucket 3 is moving, and is in an energized state when the bucket 3 is stopped. 1
9 is a battery.

In the above configuration, when the bucket 3 is performing some kind of movement alone or together with the arm 2 and boom 1, that is, when the hydraulic excavator is performing some kind of work including traveling to the main body and turning, the speed sensor 7 detects the movement of the bucket 3 and inputs a bucket movement signal to the controller 18, so the output from the controller 18 to the electromagnetic coil 17a of the lever drive device 17 becomes O. Therefore, the lever drive device @17 is non-1. lI!
At the i11 position, the stop lever 13b of the engine control device 13 is held at the normal position @P1, so that the governor 12 can be freely operated by the main control section 13a. That is, engine 8
is operated at the set rotational speed commanded by the throttle lever 14.

A hydraulic pump 9 is driven by the engine 8, and its discharged oil is guided to a directional control valve 11, and an actuator 10 is driven by the operation of the directional control valve 11 in response to operation of an operating lever (not shown).

In this way, the steady operating state of the engine 8 is maintained while the bucket 3 is making some movement, that is, while the hydraulic excavator is in the working state.

Therefore, not only while the control lever is being operated, but even if the control lever is returned to the neutral position, the steady engine operating state is maintained while the bucket 3 is actually moving, such as when turning in neutral flow. It will be done. Therefore, there is no response delay even when a reverse rotation is made immediately after a neutral flow rotation.

Next, when the movement of the bucket 3 stops, the speed sensor 7 reads the bucket speed O and outputs a bucket stop signal to the controller 18, so that an actuation signal is input from the controller 18 to the electromagnetic coil 17a of the lever drive device 17. The device 17 switches to the control position. As a result, the stop lever 13b is switched to the low speed position faPz, so that the governor 12 is commanded to have a low rotational speed, and the engine 8 is automatically set to low rotational speed. In this way, fuel consumption during downtime is saved and engine noise is suppressed.

When the work is restarted, the speed sensor 7 detects the bucket movement, inputs this bucket movement signal to the controller 18, stops outputting the actuation signal from the controller 18 to the lever drive device 17, and stops the stop lever 13.
By returning b to the normal position P1, the engine 8 returns to a steady operating state.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and repeated explanation thereof will be omitted.

20 is an engine control device in which a throttle lever 14 and a governor lever 16 are connected to a loose spring 21;
They are interlocked and connected via a link 22 and a rod 23.

24 controls the operation of this engine control device 20 by υI.
A deceleration solenoid serves as a control means for controlling the deceleration solenoid 24, and a case 24a of the deceleration solenoid 24 is connected to a link 22 of the engine control device 20. In addition, a connecting tool 25 is fixed to a movable iron core (piston) 24b of the solenoid 24, and a long hole 25a of this connecting tool 25 has a
A pin 26 fixed to the intermediate portion of the governor lever 16 is engaged.

On the other hand, in this second embodiment, the controller 18 outputs an activation signal to the deceleration solenoid 24 when the bucket movement signal is input from the speed sensor 7, and the output becomes 0 when the bucket stop signal is input. Become.

The decel solenoid 24 is in an extended state as shown in the figure when the output from the controller 18 is O (de-energized), and is energized by an actuation signal from the controller 18 when the bucket is moved, and becomes a contracted state. At this time, the connector 25 is pulled to the left as shown by the imaginary line in the figure, so that the bottle 26 is positioned in the middle of the elongated hole 25a of the connector 25. That is, the elongated hole 25a is in the non-control position where the movement of the bin 26 is not restricted (the deceleration solenoid 24 does not intervene in the operation of the engine control device 20), and the governor lever 16 freely rotates from the engine stop position A to the full rotation position C. be kept in good condition.

When the bucket 3 stops moving, a bucket stop signal is input from the speed sensor 7 to the controller 18, and the actuation signal from the controller 18 to the deceleration solenoid 24 is released, so that the deceleration solenoid 24 is demagnetized. As a result, the connector 25 is returned to the position shown by the solid line in FIG. 2, the deceleration solenoid 24 is switched to a control position that intervenes in the operation of the engine control device 20, and the governor lever 16 is set to the low speed position. In this way, the engine 8 shifts to low speed rotation.

By the way, as a control means of the engine control device, instead of the lever driving device @17 of the first embodiment and the deceleration solenoid 24 of the second embodiment, a [1 valve] which is turned on and off by a signal from the controller 18 is used. A hydraulic cylinder that expands and contracts by turning on and off this solenoid valve may be used.

Furthermore, the present invention is not limited to hydraulic excavators, but can also be applied to other excavating machines, such as wheel loaders, that include a bucket as a work attachment element.

(Effect of the invention) As described above, according to the present invention, the judgment of work stoppage is
This is not done by detecting whether the operating lever is in the neutral position as in the past, but by detecting whether the bucket is moving or not, so the sensor for detection is not connected to the bucket. At most three, at least one. Therefore, the sensor cost is much lower than in the conventional device, which requires at least six sensors for each operating lever. Furthermore, since the sensor is provided in the bucket, it is easy to attach the sensor to existing machines.

Furthermore, regardless of the neutral position of the operating lever, the engine rotation is not switched to low speed while the bucket is actually moving, so for example, when a hydraulic excavator immediately shifts to reverse rotation after turning in neutral flow, There is no delay in high-speed recovery.

[Brief explanation of the drawing]

FIG. 1 is a control system explanatory diagram showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram of a control system showing a second embodiment, and FIG. 3 is a side view of a hydraulic excavator to which the present invention is applied. A... Excavation work machine main body, B... Work attachment, 1... Boom of the same attachment, 2... Same arm, 3... Same bucket, 7... Sensor, 8...
Engine, 9... Hydraulic pump, 10... Actuator, 11... Direction control valve, 12... Governor (engine speed setting device), 13... Engine control device, 13a... The same device main control section, 13b...stop lever, 17...lever drive device as control means, 1B...controller, 2
0... Engine control device, 24... Deceleration solenoid as control means.

Claims (1)

[Claims] 1. The excavation work machine is equipped with a work attachment including a bucket as an element, and is driven by an engine mounted on the main body, a hydraulic pump driven by this engine, and pressure oil from the hydraulic pump. an actuator that is operated, an operation control device that controls the operation of the actuator, an engine speed setting device that sets the engine speed, and an engine control that operates the engine speed setting device to command a set engine speed. an excavation work machine comprising: a control means for controlling the operation of the engine control device; a sensor provided on the bucket of the work attachment to detect movement or stoppage of the bucket; and a bucket movement signal from the sensor. or a controller that receives a bucket stop signal and outputs a signal corresponding to the input signal to the control means, and the control means controls the engine by controlling the output signal from the controller based on the bucket stop signal from the sensor. The engine control device is controlled by a position that intervenes in the operation of the control device and controls the engine control device so that the engine speed commanded by the device becomes a low speed rotation speed, and an output signal from the controller based on the bucket movement signal from the sensor. An engine speed control device for an excavating machine, characterized in that it is configured to be switched to a position that does not interfere with the operation of the engine.