JP4490654B2 - Accelerator control device for work equipment - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an accelerator control device that controls the engine speed during remote operation of a working machine or the like equipped with a hydraulic actuator that uses a hydraulic pump driven by a vehicle engine via a power take-off (PTO) as a hydraulic source. Is.
[0002]
[Prior art]
Usually used in a working machine that operates a hydraulic actuator using pressure oil discharged from a hydraulic pump driven by a PTO to a vehicle engine, for example, a vehicle-mounted crane as shown in FIG. The hydraulic pump is a constant discharge type hydraulic pump that is inexpensive and has a simple internal structure. In order to increase the discharge amount of the hydraulic pump, the number of rotations of the hydraulic pump is increased to increase the discharge amount by increasing the number of rotations of the engine connected to the PTO.
[0003]
In a vehicle-mounted crane 1 as shown in FIG. 1, a column 6 is pivotably provided on a base 4 having an outrigger 2, and a boom 7 that extends and contracts at the upper end of the column 6 is pivotally supported. ing.
A winch 11 is provided in the column 6, and a wire rope 12 is led from the winch 11 to the tip of the boom 7, and is attached to a hook 13 for a suspended load via a pulley (not shown) at the tip of the boom 7. By hooking, the hook 13 is suspended from the tip of the boom 7. In this crane 1, as a hydraulic actuator for turning the column 6, raising and lowering and extending and retracting the boom 7, and lifting and lowering the winch 11, the turning hydraulic motor 5, the boom raising and lowering hydraulic cylinder 9, and the boom extend and retract, respectively. The hydraulic cylinder 8 for winches and the hydraulic motor 10 for winches are provided.
[0004]
In the vehicle-mounted crane 1, the oil discharged from the hydraulic pump 17 is supplied to the hydraulic actuators 5, 8, 9, 10 via the switching control valve device 3 as shown in FIG. 2. The switching control valve device 3 is a multi-connecting valve device configured by connecting a plurality of switching control valves 31, 32, 33, 34 that respectively control the hydraulic actuators 5, 8, 9, 10. In such a vehicle-mounted crane 1, remote control using a remote controller is generally performed. In that case, switching control is performed using a remote controller 20 as shown in FIGS. 3 and 4. The valve device 3 is switched.
[0005]
The remote controller 20 has two operations, that is, a boom 7 raising / lowering operation, a winch 11 hoisting / lowering operation, a boom 7 extending / contracting operation, and a column 6 left / right turning operation necessary for operating the crane 1. The joysticks 21 and 22 are used, and the left joystick 21 is divided into 4 out of 8 operations, and the right joystick 22 is divided into the remaining 4 operations.
[0006]
The remote controller 20 is also provided with an accelerator lever 23 that controls the engine speed in order to vary the operating speed of the hydraulic actuator.
[0007]
The remote controller 20 operates a joystick and a pistol trigger so that the operator can hold the grip portion 24, operate each joystick 21 or 22 with the thumb, and operate the accelerator lever 23 with the index finger. The layout of the type accelerator lever is considered.
[0008]
The operation signal of the hydraulic actuator according to the tilt amount of each joystick 21 and 22 and the operation signal according to the pulling amount of the accelerator lever 23 are directed from the remote controller 20 to the receiver 25 provided on the switching control valve device 3 side. Wirelessly transmitted.
When the joysticks 21 and 22 are operated, the main spools for switching the hydraulic fluid paths of the hydraulic actuators 5, 8, 9, and 10 of the switching control valve device 3 are displaced according to the operation amount, and the respective hydraulic actuators are operated. Operates according to quantity.
[0009]
When the accelerator lever 23 is operated, the engine speed of the vehicle increases according to the amount of operation. The discharge amount of the hydraulic pump 17 increases in proportion to the increase in the engine speed, and the operating speed of each hydraulic actuator 5, 8, 9, 10 increases.
[0010]
However, when the operator operates each joystick 21 or 22 with the thumb while holding the grip portion 24 of the remote controller 20 with one hand and pulls the accelerator lever 23 with the index finger, the amount of operation of the joysticks 21 and 22 is increased. It is difficult to operate while adjusting the operation amount of the accelerator lever 23 individually. This is because only the accelerator lever 23 is pulled before operating the joysticks 21 and 22, or the pulling amount of the accelerator lever 23 with respect to the operation amount of the joysticks 21 and 22 becomes excessively large, and the engine is emptied. This is because it often happens.
[0011]
In addition, when only the accelerator lever 23 is operated without operating the joysticks 21 and 22, only the engine is left empty even though the hydraulic actuator does not operate. Since the amount of oil discharged from the hydraulic pump 17 is determined by the number of engine revolutions, a large amount of pressure oil is wasted from the hydraulic pump 17 and the pressure oil temperature rises accordingly. The engine noise increases as the engine speed increases.
[0012]
As an example of using a remote controller using a joystick, the tilt of the remote controller is controlled by a tilt sensor provided in the remote controller without using an accelerator lever for engine speed control as a control device for engine speed by remote control. There is one that senses and controls the engine speed by the amount of tilt angle. That is, in this remote controller, each hydraulic actuator is operated according to the amount of operation by joystick operation, and when the engine speed is increased to increase the operating speed of each hydraulic actuator, the remote controller is tilted. (See Patent Document 1).
[0013]
In this remote controller, in the neutral state where the joystick is not operated, even if the remote controller is tilted and the engine speed is increased, the signal from the tilt sensor becomes invalid on the arithmetic unit side, and the engine It is not possible to increase the rotation speed.
However, in order to control the engine speed by tilting the remote controller, it is necessary to finely control the inclination of the remote controller with the hand holding the remote controller, which is not intended by the operator during crane operation. If the remote controller is tilted without any change, the engine speed easily rises or falls, making it difficult to control the speed appropriately even if the operator is an expert.
[0014]
[Patent Document 1]
Japanese Patent Laid-Open No. 61-2692
[Problems to be solved by the invention]
The present invention solves the above-described problem in an accelerator control device for a work machine such as a crane, and discharges hydraulic oil necessary for the operation of a hydraulic actuator efficiently from a hydraulic pump by appropriately controlling the engine speed. Let Accordingly, it is an object of the present invention to provide an accelerator control device that suppresses unnecessary engine idling and an increase in pressure oil temperature and reduces noise generated by the engine as much as possible.
[0016]
[Means for Solving the Problems]
The accelerator control device of the present invention drives a joystick for remotely operating a predetermined hydraulic actuator and an accelerator of the engine in a work machine including a plurality of hydraulic actuators that operate using a hydraulic pump driven by a vehicle engine as a hydraulic source. A new accelerator function formula is generated by multiplying the basic accelerator function formula stored in advance and the basic accelerator function formula stored in advance by the operation ratio of the actual joystick manipulated variable. Substituting the operation amount of the accelerator lever into the obtained accelerator function formula, the accelerator operation amount is obtained, and the operation device that outputs the accelerator control signal is provided , and the operation ratio of the actual operation amount of the joystick decreases. As is, by reducing also the inclination of the obtained accelerator function formula, the problem Solution to that.
[0017]
In the arithmetic unit of the accelerator control device of this work machine, the operation ratio (%) of the operation amount actually performed with respect to the maximum operation amount with respect to the maximum operation amount of the joystick in the remote controller is obtained and stored. A new accelerator function equation is generated by multiplying the basic accelerator function equation by the operation ratio, and the accelerator lever operation amount is substituted into the obtained accelerator function equation to obtain the accelerator operation amount.
[0018]
When the operation amount of the joystick is 0, that is, in the neutral state, the operation ratio is 0%. Therefore, the accelerator function equation obtained by multiplying the basic accelerator function equation by 0% is a function equation in which the accelerator operation amount is 0 and is constant. It is. Therefore, even if the accelerator lever is operated, the accelerator operation amount becomes 0, and the engine speed of the vehicle does not increase.
[0019]
Further, when the operation amount of the joystick is half of the maximum operation amount of the joystick, the operation ratio is 50%. Therefore, the accelerator function equation obtained by multiplying the basic accelerator function equation by 50% is the basic accelerator function. This is a functional expression that gives an accelerator operating amount of 50% of the overall accelerator operating amount. Therefore, even if the accelerator lever is operated to the maximum, the accelerator operation amount is halved, and the engine speed of the vehicle does not reach the maximum speed.
[0020]
When the operation amount of the joystick is the maximum operation amount, the operation ratio is 100%. Therefore, the basic accelerator function equation is multiplied by 100%, so that the obtained accelerator function equation remains the basic accelerator function equation. Therefore, if the accelerator lever is operated to the maximum, the accelerator operation amount is also maximized, and the engine speed of the vehicle reaches the maximum rotation.
[0021]
In the case of multiple operations where multiple hydraulic actuators are operated simultaneously, the arithmetic unit selects the one with the largest operation amount from the input operation signals of each joystick, obtains the operation ratio, and determines the basic accelerator. The operation rate is multiplied by the operation ratio, and the accelerator lever operation amount is substituted into the obtained accelerator function equation to obtain the accelerator operation amount.
[0022]
Therefore, the accelerator control device of the working machine can perform efficient work by suppressing unnecessary engine idling and increase in pressure oil temperature, and reducing noise generated by the engine as much as possible. .
[0023]
DETAILED DESCRIPTION OF THE INVENTION
【Example】
Next, specific examples of the present invention will be described.
FIG. 1 is a configuration diagram of a crane 1, FIG. 2 is a configuration diagram of an accelerator control device for a working machine showing an embodiment of the present invention, FIG. 3 is a front view of a remote controller, and FIG. 4 is a side view of the remote controller. 5 and 6 are flowcharts when the accelerator control cylinder is controlled by the arithmetic unit, and FIG. 7 is a diagram showing an example of an accelerator function equation.
Since the construction of the crane is the same as the conventional one, it will be described with reference to FIG.
[0024]
In the vehicle-mounted crane 1 shown in FIG. 1, a column 6 is pivotably provided on a base 4 provided with an outrigger 2, and a boom 7 that extends and contracts at the upper end of the column 6 is pivotally supported. . A winch 11 is provided in the column 6, and a wire rope 12 is led from the winch 11 to the tip of the boom 7, and is attached to a hook 13 for a suspended load via a pulley (not shown) at the tip of the boom 7. By hooking, the hook 13 is suspended from the tip of the boom 7.
[0025]
The crane 1 includes a swing hydraulic motor 5, a boom hoisting hydraulic cylinder 9, and a boom telescopic hydraulic pressure as hydraulic actuators for turning the column 6, raising and lowering and extending and retracting the boom 7, and winding and unwinding the winch 11, respectively. A cylinder 8 and a winch hydraulic motor 10 are provided.
The turning hydraulic motor 5, the boom raising and lowering hydraulic cylinder 9, the boom telescopic hydraulic cylinder 8, and the winch hydraulic motor 10 are all switched from a hydraulic pump 17 driven by being connected to a PTO 16 of an engine 15 of the vehicle. It operates by supplying pressure oil through the device 3. The amount of pressure oil discharged from the hydraulic pump 17 increases as the rotational speed of the engine 15 increases.
[0026]
The switching control valve device 3 includes a swing switching control valve 31 for controlling the respective hydraulic actuators of the swing hydraulic motor 5, the boom hoisting hydraulic cylinder 9, the boom telescopic hydraulic cylinder 8, and the winch hydraulic motor 10. This is a multi-connected valve device configured by connecting a boom raising / lowering switching control valve 32, a boom expansion / contraction switching control valve 33, and a winch switching control valve 34. Remote operation by the joysticks 21 and 22 is possible.
[0027]
As shown in FIGS. 3 and 4, the remote controller 20 controls eight operations of the boom 7 undulation operation, the winch 11 hoisting and lowering operation, the boom 7 telescopic operation, and the column 6 swiveling operation to the left and right. Two joysticks 21 and 22 and an accelerator lever 23 for controlling the accelerator of the vehicle engine 15 provided separately from the joystick are provided. When the joystick 22 on the right side when viewed from the front of the remote controller 20 is tilted up and down, the main spool of the boom hoisting switching control valve 32 is displaced according to the tilting amount, and the boom 7 performs hoisting operation and tilts left and right. When the main spool of the winch switching control valve 34 is displaced according to the tilting amount, the winch 11 performs the hoisting / lowering operation, and when the other left joystick 21 tilts up and down, the main of the boom extension switching control valve 33 is controlled. The spool is displaced according to the tilt amount, the boom 7 is expanded and contracted, and when tilted to the left and right, the main spool of the turning switching control valve 31 is displaced according to the tilt amount, and the column 6 performs the left and right swing operation. Like to do. Note that the operation positions of the joysticks 21 and 22 are merely examples, and combinations thereof can be determined as appropriate.
[0028]
In the above example, when the joystick 22 is tilted to the upper right, the main spool of the boom raising / lowering switching control valve 32 and the main spool of the winch switching control valve 34 are displaced according to the tilting amount, and the boom 7 is raised. The winch 11 is operated to wind down. It goes without saying that the operation amount of each hydraulic actuator depends on the tilt amount based on the tilt direction of the joysticks 21 and 22.
[0029]
Although not shown, four joysticks of two operations are used to perform the hoisting operation of the boom 7, the hoisting and lowering operation of the winch 11, the telescopic operation of the boom 7, and the left and right pivoting operations of the column 6 with each joystick. You can also
[0030]
The joysticks 21 and 22 output potentiometers and capacitive sensors, such as those using the product name PicoPoint (registered trademark), and output analog signals. The analog signal changes according to the operation amount. The accelerator lever 23 is also configured to output an analog signal by using a potentiometer or a capacitive sensor such as one using the above-mentioned product name PicoPoint (registered trademark). The analog signal changes according to the amount.
[0031]
An operation signal corresponding to the tilt amount of the joysticks 21 and 22 and an operation signal corresponding to the pulling amount of the accelerator lever 23 are wirelessly transmitted from the remote controller 20 to the receiver 25 on the switching control valve device 3 side. And input to the arithmetic unit 30.
Each switching control valve 31, 32, 33, 34 has a built-in main spool, and a position detector 40 for detecting the displacement of each main spool and feeding it back to the arithmetic unit 30. The main spool is normally held in a neutral position by left and right springs, and one end of the main spool is connected to the operation lever 14 via a link.
[0032]
In addition, a pilot piston 37 is connected to the main spool, and a proportional electromagnetic pilot valve 41 is provided in each of the switching control valves 31, 32, 33, 34. The proportional electromagnetic pilot valve 41 has a port E to which the pilot pressure oil is supplied from the hydraulic pump 17 via the pressure reducing valve 35 is normally closed, and a port F for returning the hydraulic oil to the tank 18 is normally open. When a control current is input from 30 to the solenoid 42L or 42R, the pilot spool 43L or 43R slides, and the opening amount of the E port can be controlled by the input voltage value. Accordingly, the supply of pilot pressure oil to the left and right oil chambers 37L or 37R of the pilot piston 37 is controlled.
[0033]
When the pilot pressure oil is supplied to either one of the oil chambers 37R or 37L, the main spool moves to the left or right to connect the service port and the pump port, so that each control switching valve 31, 32, 33 , 34 actuate the respective hydraulic actuators of the swing hydraulic motor 5, the boom hoisting hydraulic cylinder 9, the boom telescopic hydraulic cylinder 8, and the winch hydraulic motor 10.
Between the pump port and the tank port, there is provided a main relief valve 38 and an unloading solenoid valve 39 for opening the main relief valve 38 when unloading is necessary and communicating the pump port and the tank port. It has been.
[0034]
The arithmetic unit 30 stores a basic accelerator function equation in advance, and this basic accelerator function equation is common to the hydraulic actuators 5, 8, 9, and 10. As will be described later, the arithmetic unit 30 obtains an accelerator control cylinder operation amount based on the basic accelerator function equation, the operation amounts of the joysticks 21 and 22 of the remote controller 20 and the operation amount of the accelerator lever 23, and determines the accelerator control cylinder 50. An accelerator control signal is output to the proportional electromagnetic pilot valve 51 to be operated.
The accelerator control cylinder 50 is provided with a position detector 53 for detecting the displacement of the piston 52 and feeding it back to the arithmetic unit 30.
[0035]
Next, the operation of the accelerator control device by the arithmetic device 30 will be described with reference to FIG.
For example, when the operation of reducing the boom 7 is described, the operator operates the joystick 21 on the left side of the remote controller 20 to the lower side, which is the reduction side of the boom 7, and pulls the accelerator lever 23. The arithmetic unit 30 reads the operation amount of the joystick 21 and calculates the operation ratio with respect to the maximum operation amount of the joystick.
[0036]
By multiplying the basic accelerator function equation by the calculated operation ratio, a new accelerator function expression after the operation ratio multiplication as shown in FIG. 7 is obtained. Next, the amount of operation of the accelerator lever 23 is read, the amount of operation of the accelerator lever is obtained by substituting the amount of operation of the accelerator lever into this function equation, and an accelerator control signal is output.
The arithmetic unit 30 sends the accelerator control cylinder operation amount A as an accelerator control signal to the proportional electromagnetic pilot valve 51 that operates the accelerator control cylinder 50 to operate the accelerator control cylinder 50. The position detector 53 of the accelerator control cylinder 50 feeds back the detected value to the arithmetic unit 30 and corrects if there is excess or deficiency.
[0037]
In addition, the order of the control flow shown in FIG. 5 can be changed and performed in the order shown in FIG. In this case, the calculation result of the accelerator control cylinder operation amount with respect to the operation amount of the joystick and the operation amount of the accelerator lever is finally the same as described above.
For example, when the operation for reducing the boom 7 is described, the operator operates the joystick 21 on the left side of the remote controller 20 to the lower side, which is the reduction side of the boom 7, and pulls the accelerator lever 23.
[0038]
The arithmetic unit 30 reads the operation amount of the accelerator lever 23, substitutes the accelerator lever operation amount into the basic accelerator function equation, and obtains the accelerator control cylinder operation amount B before the operation ratio multiplication. Next, the operation amount of the joystick 21 is read, the operation ratio with respect to the maximum operation amount of the joystick is calculated, the accelerator control cylinder operation amount B before the operation ratio multiplication is multiplied by the calculated operation ratio, and the accelerator control cylinder operation amount A is calculated. The accelerator control signal is output.
[0039]
The arithmetic unit 30 sends the accelerator control cylinder operation amount A as an accelerator control signal to the proportional electromagnetic pilot valve 51 that operates the accelerator control cylinder 50 to operate the accelerator control cylinder 50. The position detector 53 of the accelerator control cylinder 50 feeds back the detected value to the arithmetic unit 30 and corrects if there is excess or deficiency.
[0040]
When the left joystick 21 is operated in the diagonally downward direction in order to perform the boom 7 reduction operation and the column 6 left-turning operation simultaneously, or the boom 7 reduction operation and the winch 11 hoisting operation are performed simultaneously. When operating the left joystick 21 and the right joystick 22 simultaneously, the arithmetic unit 30 has the largest operation amount among the input operation signals of the joysticks 21 and 22. The larger one is calculated as the operation ratio with respect to the maximum operation amount of the joystick.
Further, the operation amount of the accelerator lever 23 and the operation amount of the accelerator control cylinder 50 may be calculated as a numerical value in mm as shown in FIG. 7, or may be performed at a ratio where the maximum operation amount and the maximum operation amount are 100%. Good.
[0041]
【The invention's effect】
According to the accelerator control device for a working machine according to the present invention, it is possible to prevent an unnecessary increase in the engine speed, and to perform appropriate accelerator control without causing the engine to empty. A large amount of pressure oil is discharged, the rise in pressure oil temperature is suppressed, engine noise is reduced, and efficient work can be performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a crane.
FIG. 2 is a configuration diagram of an accelerator control device for a working machine according to an embodiment of the present invention.
FIG. 3 is a front view of the remote controller.
FIG. 4 is a side view of the remote controller.
FIG. 5 is a flowchart when an accelerator control cylinder is controlled by an arithmetic unit.
FIG. 6 is a flowchart when the accelerator control cylinder is controlled by the arithmetic device.
FIG. 7 is a diagram illustrating an example of an accelerator function equation;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Crane 3 Switching control valve apparatus 4 Base 5 Turning hydraulic motor 6 Column 7 Boom 8 Boom expansion / contraction hydraulic cylinder 9 Boom raising / lowering hydraulic cylinder 10 Winch hydraulic motor 11 Winch 12 Wire rope 15 Engine 17 Hydraulic pump 20 Remote controller 21 Joystick 22 Joystick 23 Accelerator lever 24 Grasping part 25 Receiver 30 Arithmetic unit 31 Switching control valve for turning 32 Switching control valve for raising / lowering boom 33 Switching control valve for boom expansion / contraction 34 Switching control valve for winch 37 Pilot piston 40 Position detector 41 Proportional Electromagnetic pilot valve 50 Accelerator control cylinder 53 Position detector

Claims (1)

In a working machine having a plurality of hydraulic actuators that operate using a hydraulic pump driven by a vehicle engine as a hydraulic source, a joystick that remotely operates a predetermined hydraulic actuator, and an accelerator lever that remotely controls an actuator that drives an engine accelerator A new accelerator function expression is generated by multiplying the basic accelerator function expression stored in advance and the basic accelerator function expression stored in advance by the operation ratio of the actual operation amount of the joystick, and the accelerator lever is added to the obtained accelerator function expression. The operation amount is obtained by substituting the operation amount of the control unit, and an operation device that outputs an accelerator control signal is provided, and as the operation ratio of the actual operation amount of the joystick decreases, the obtained operation amount is obtained. the accelerator control of the working machine, characterized in that also decreases the inclination of the accelerator function formula

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