JP2003182974A - Controller for control valve of hydraulic working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase a control range of driving speed only by an operation of an accelerator pedal 1 for an engine 2, in a hydraulic working machine designed to control discharge oil of a pump 3 driven by the engine 2 with a control valve 5 in driving an actuator 4. <P>SOLUTION: A controller for a control valve of a hydraulic working machine comprises an operating lever signal outputting means 7, an accelerator signal outputting means 9, an operating-lever-responsive changeover range upper limit setting means 10 for setting an upper limit of a changeable range of the control valve 5 by an operating lever signal, to an arbitrary value not higher than a changeover level of the control valve 5 necessary and sufficient to supply the total discharge rate of the pump 3 to the actuator under a low engine speed, and a valve control signal output part 8 for receiving a signal from each of the means 7, 9 and 10 and outputting valve control signals b1 and b2 for controlling the control valve 5. The valve control signal output part 8 controls the control valve 5 in the operating-lever-responsive changeover range according to the operating lever signal (a), and controls the control valve 5 beyond the operating-lever-responsive changeover range according to the signal from the accelerator signal outputting means 9. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a control valve of a hydraulic working machine such as a mobile crane or an aerial work vehicle. 2. Description of the Related Art As shown in FIG. 3, a hydraulic working machine to which the present invention is applied has its rotation speed arbitrarily controlled between a low rotation speed and a high rotation speed by operating an accelerator pedal 1. It comprises a possible engine 2, a hydraulic pump 3 driven by the engine 2, and a control valve 5 for controlling the amount of hydraulic oil supplied to the hydraulic actuator 4 from the hydraulic pump 3. The control valve 5 has a maximum switching amount (maximum opening degree), and a substantially entire amount of a maximum discharge oil amount of the hydraulic pump 3 (discharge oil amount when the engine 2 is set to a high rotational speed) is set as a control oil amount. 4 can be supplied. A conventional control device for controlling the switching of the control valve 5 includes an operation lever signal output means 7 which is attached to the operation lever 6 and outputs an operation lever signal a in response to the operation of the operation lever 6; Operation lever signal output means 7
And a valve control signal output unit 8 for receiving valve lever signals a from the controller and outputting valve control signals b1 and b2 for switching control of the control valve 5. When the operating lever 6 is tilted from the neutral position in the forward or reverse direction, an operating lever signal a corresponding to the tilting operation is output from the operating lever signal output means 7 to the valve control signal output section 8. The valve control signal output unit 8 outputs valve control signals b1 and b2 corresponding to the received operation lever signal a to the drive unit of the control valve 5. As a result, the control valve 5 (the spool of the control valve 5) is switched to the switching amount (opening degree) corresponding to the forward or backward tilt operation amount of the operation lever 6 from the neutral position to the neutral position.
In the forward or reverse direction. In this case, the relationship between the operation lever 6 and the control valve 5 is such that when the operation lever 6 is tilted in the forward or reverse direction from the neutral position to the maximum, the control valve 5 (control valve 5 spool) moves from the neutral position to the maximum switching amount ( (Maximum opening). [0005] In the hydraulic working machine provided with the conventional control valve control device configured as described above, the control valve 5 by the mounting lever 6 is used.
By using both the spool switching amount (opening degree) control and the individual operation of controlling the engine 2 rotation speed by the accelerator pedal 1, the control oil amount can be reduced from zero to the high rotation speed of the engine 2. The drive speed of the hydraulic actuator 4 can be controlled by arbitrarily controlling the discharge oil amount (maximum discharge oil amount). In this type of hydraulic working machine, a state in which the operating lever 3 is maximally tilted in a forward or reverse direction from a neutral position (hereinafter referred to as a maximum tilting state).
In many cases, the driving speed of the hydraulic actuator 4 is controlled by the operation of the accelerator pedal 1 of the engine 2 while maintaining the pressure. According to such a method of use, since the drive speed of the hydraulic actuator 4 can be changed and controlled only by operating the accelerator pedal 1, there is an advantage that the degree of fatigue of the operator is small. This advantage is particularly significant when the operation lever 6 is of a dendescent type (having a function of maintaining the maximum tilting position even when the hand is released at the maximum tilting position). When such a method of use is used in the above-described conventional control valve control device, the fluctuation range of the driving speed of the hydraulic actuator 4 which can be realized only by operating the accelerator pedal 1 is limited to the low rotation speed of the engine 2. The lower limit speed at which the entire amount of oil discharged from the hydraulic pump 3 is supplied to the hydraulic actuator 4 as control oil for the control valve 5 and the substantially entire amount of oil discharged from the hydraulic pump 2 at a high rotational speed of the engine 2 It is between the upper limit speed obtained by being supplied to the hydraulic actuator 4 as control oil. In other words, the lower limit speed of the hydraulic actuator 4 that can be realized only by the operation of the accelerator pedal 1 is such that the entire amount of oil discharged from the hydraulic pump 3 at a low rotational speed of the engine 2 is used as control oil for the control valve 5. , And cannot be realized at a lower speed. According to the present invention, in the above-mentioned operation method,
The lower limit speed of the hydraulic actuator 4 that can be realized only by the operation of the accelerator pedal 1 is the speed obtained by supplying the entire amount of the discharge oil of the hydraulic pump 3 at the low rotation speed of the engine 2 to the hydraulic actuator 4 as the control oil of the control valve 5. It is an object of the present invention to provide a control device for a control valve which can be lower than the above. [0011] To achieve the above object, a control device for a control valve of a hydraulic working machine according to the present invention is configured as follows. An engine 2 whose rotation speed can be arbitrarily controlled between a low rotation speed and a high rotation speed by operating an accelerator pedal 1, a hydraulic pump 3 driven by the engine 2, and a hydraulic pump 3 A control valve for controlling the control valve 5 of the hydraulic working machine, comprising: a control valve 5 for controlling a supply amount of hydraulic oil from the control lever; and an operation lever that outputs an operation lever signal a in response to operation of the operation lever 6. Signal output means 7 ・ the accelerator pedal 1 being linked to the accelerator pedal 1
Accelerator signal output means 9 for outputting an accelerator signal c in response to the operation of the control valve 5. The upper limit of the control valve 5 spool switchable area by the operation lever signal a is set to the total amount of the oil discharged from the hydraulic pump 3 at the low rotation speed of the engine 2. Control valve 5 that is necessary and sufficient to supply the hydraulic actuator 4 with an operating lever response control range upper limit setting signal for outputting an operating lever response control range upper limit setting signal d for setting to an arbitrary value equal to or less than the spool switching amount. Means 10, a valve control signal b for receiving signals a, c, d from the means 7, 9, 10 to switch and control the control valve.
1, a valve control signal output unit 8 for outputting b2,
The valve control signal output unit 8 controls the switching of the control valve 5 spool within the operation lever response switching area defined by the operation lever response switching area upper limit setting signal d based on the operation lever signal a. The control valve 5 is configured to generate and output the valve control signals b1 and b2 so that the switching control of the control valve 5 spool exceeding the operation lever response switching area defined by the switching area upper limit setting signal d is performed in response to the accelerator signal c. A control device for a control valve of a hydraulic working machine, comprising: In the control device for a control valve of a hydraulic working machine according to the present invention configured as described above, the lower limit speed of the hydraulic actuator 4 that can be realized only by the operation of the accelerator pedal 1 is set at the low rotational speed of the engine 2. When the total amount of the discharge oil of the hydraulic pump 3 is to be lower than the speed obtained by being supplied to the hydraulic actuator 4 as the control oil of the control valve 5, the operation lever response switching range upper limit setting means is operated. The upper limit of the switchable range of the control valve spool based on the operation lever signal a is as follows: “The entire amount of oil discharged from the hydraulic pump 3 at the low rotation speed of the engine 2 is
Control valve spool switching amount necessary to supply
An operation lever response switching range upper limit setting signal d to be set to the following arbitrary switching amount is output. The valve control signal output unit 8 which has received the operation lever response switching area upper limit setting signal d receives the operation lever response upper limit of the operation lever response switching area of the control valve 5 which can be switched by operating the operation lever 6. It is changed according to the response switching range upper limit setting signal d. The operation lever response switching region is a switching region in which the control valve 5 has a switching amount of zero (neutral position) to an upper limit set by the operation lever response switching region upper limit setting signal d. Next, the operation lever 6 is tilted to the maximum tilt state. In this state, the operation lever signal a responds to the maximum tilting operation of the operation lever 6, but the upper limit of the operation lever response switching area in the valve control signal output unit 8 indicates “the hydraulic pressure at the low rotational speed of the engine 2. The control valve spool is set to an arbitrary switching amount equal to or less than "a control valve spool switching amount necessary and sufficient to supply the entire amount of the discharge oil of the pump 3 to the hydraulic actuator 4". A part of the discharge amount of No. 3 is switched to a switching amount to be supplied to the hydraulic actuator 4 as its control oil. The remaining part of the discharge amount of the hydraulic pump returns to the tank through a relief valve or the like arranged in the pump oil passage. In this state, the driving speed of the hydraulic actuator 4 is lower than the speed obtained by supplying the entire amount of the discharge oil of the hydraulic pump 3 to the hydraulic actuator 4 at the low rotation speed of the engine 2. The valve control signal output means 8 has an operating lever response switching area defined by the operating lever response switching area upper limit setting signal d (the upper limit of which can be arbitrarily set by the operating lever response switching area setting means). The control switching of the control valve 5 spool is performed based on the operation lever signal a, and the control valve 5 exceeds the operation lever response switching area defined by the operation lever response switching area upper limit setting signal d.
Since the spool switching control is performed in response to the accelerator signal c, the valve control signals b1 and b2 are generated and output. Therefore, in the above-described state, the rotation speed of the engine 2 is reduced by the accelerator pedal 1. By controlling the rotational speed from the rotational speed to the high rotational speed, the control valve 5 can be switched and controlled beyond the operation lever response switching range. Therefore, according to the control device for a control valve of a hydraulic working machine according to the present invention, the lower limit speed of the hydraulic actuator 4 which can be realized only by the operation of the accelerator pedal 1 is reduced by the hydraulic pump 3 at the low rotational speed of the engine 2. It is possible to set an arbitrary speed lower than the speed obtained by supplying the entire amount of the discharged oil to the hydraulic actuator 4 as the control oil of the control valve 5. An embodiment of a control device for a control valve according to the present invention will be described below with reference to FIG. The hydraulic working machine to which the control device of the control valve according to the present invention is applied, as described in the above-described prior art, can operate the accelerator pedal 1 so that the rotation speed thereof is arbitrary between a low rotation speed and a high rotation speed. The engine 2 includes a controllable engine 2, a hydraulic pump 3 driven by the engine 2, and a control valve 5 for controlling a hydraulic oil supply amount from the hydraulic pump 3 to a hydraulic actuator 4. In this embodiment, the control valve 5 is a four-way three-position type directional control valve capable of switching from a neutral position with a switching amount of zero to a forward direction and a reverse direction. The control valve is provided with a switching amount (hereinafter referred to as a “saturation switching amount at a high engine rotation speed”) required to supply the hydraulic actuator 4 with substantially all of the discharge oil of the hydraulic pump 3 at a high rotation speed of the engine 2. ) Can be switched in the forward and reverse directions. In the control valve 5, the amount of switching from the neutral position in the forward direction and the reverse direction is controlled by valve control signals b1 and b2 input to a drive unit (not shown). The control device for a control valve according to the present invention is provided with an operation lever signal output means 7 attached to the operation lever 6 for outputting an operation lever signal a in response to the operation of the operation lever 6, and is operatively connected to the accelerator pedal 1. An accelerator signal output means 9 for outputting an accelerator signal c in response to the operation of the accelerator pedal 1, a control valve 5 switchable by an operating lever signal a, and an upper limit of a switching area of the spool (an operating lever response switching area) is arbitrarily set. Lever response switching area upper limit setting means 1 for outputting an operation lever response switching area upper limit setting signal d for performing
0, and each of the means (operation lever signal output means 7,
Signals from the accelerator signal output means 9 and the operation lever response switching range upper limit setting means 10) (operation lever signal a,
A valve control signal output unit 8 which receives an accelerator signal c and an operation lever response switching range upper limit setting signal d) and outputs valve control signals b1 and b2 for switching control of the control valve 5. The operation lever signal a output from the operation lever signal output means 7 is a signal indicating the forward / reverse tilt direction and the amount of tilt from the neutral position of the operation lever 6. The accelerator signal a output from the accelerator signal output means 9 is a signal corresponding to the amount of depression of the accelerator pedal 1. The operation lever response switching area upper limit setting means 1
The operation lever response switching range upper limit setting signal d output by 0 is:
The upper limit of the switching area (switching area from the neutral position to the forward direction and switching area from the neutral position to the reverse direction) of the control valve 5 (spool of the control valve 5) switchable by the operation lever signal a is arbitrarily set. It is for doing. The upper limit of the operating lever response switching area by the operating lever response switching area upper limit setting means 10 is a control valve necessary and sufficient for causing the hydraulic actuator 4 to supply the entire amount of oil discharged from the hydraulic pump 3 at a low rotation speed of the engine 2. 5 switching amount (hereinafter, “saturation switching amount at low engine speed”)
) (Including the neutral position of the control valve 5) and a value equal to or greater than the "saturation switching amount at low engine speed" (including the "saturation switching amount at high engine speed"). It can be set arbitrarily stepwise or continuously between them. FIG. 2 is an explanatory diagram of the operation lever response switching area in which the upper limit is set by the operation lever response switching area upper limit setting means 10. FIG. 2 shows only the forward switching area of the control valve 5. In FIG. 2, the switching range of the switching valve 5 is from the neutral position O to the “saturation switching amount at high engine speed” X2 (substantially the entire amount of oil discharged from the hydraulic pump 3 at high engine speed (The amount of switching required to supply). The upper limit of the operation lever response switching area is set to “the saturation switching amount at low engine speed” by the operation lever response switching area upper limit setting means X.
It is possible to arbitrarily set stepwise or continuously between a value Y1 sufficiently smaller than 1 and a value Y2 equal to or greater than the "saturation switching amount at low engine speed" X1. In this example, Y1 is set between the neutral position O and the "saturation switching amount at low engine speed" Y1. However, Y1 may be set to the neutral position. Y2 is set at a position that slightly exceeds the "saturation switching amount at low engine speed" Y1, but this Y2 is set at "saturation switching amount Y2 at high engine speed". The operation lever response switching area in which the upper limit of the switching area is changed stepwise or continuously in the range of Y1 to Y2 by the operation lever response switching area upper limit setting means 10 is from the neutral position O to Y1. In the range from the neutral position O to Y2, it can be changed in a stepwise or continuous manner [0028] Returning to Fig. 1, the valve control signal output section 8 includes an operation lever signal output means 7, an accelerator, An operation lever signal a, an accelerator signal c, and an operation lever response switching area upper limit setting signal d are received from the signal output means 9 and the operation lever response switching area upper limit setting means 10, and are subjected to arithmetic processing. It outputs valve control signals b1 and b2 for switching control of the control valve 5. The valve control signal output section 8 is provided for controlling the operation lever response defined by the operation lever response switching range upper limit setting signal d. The switching control of the control valve 5 spool in the switching area is performed based on the operating lever signal a, and the switching control of the control valve 5 spool exceeding the operating lever response switching area defined by the operating lever response switching area upper limit setting signal d is performed. A valve control signal is generated and output so as to be performed in response to the accelerator signal c.Effects of the present invention A control device for a hydraulic working machine according to the present invention configured and operated as described above. Is the lower limit speed of the hydraulic actuator 4 which can be realized only by the operation of the accelerator pedal 1, and the total amount of the discharge oil of the hydraulic pump 3 at the low rotation speed of the engine 2 is It is possible to set an arbitrary speed lower than the speed obtained by being supplied as the control oil to the hydraulic actuator 4. In other words, the range in which the drive speed of the hydraulic actuator 4 can be changed and controlled only by operating the accelerator pedal 1 is greatly increased. There is the advantage that it can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a control device for a control valve of a hydraulic working machine according to the present invention. FIG. 2 is an explanatory diagram of an operation lever response switching area in the control device of the present invention. FIG. 3 is an explanatory diagram of a conventional control device for a control valve of a hydraulic working machine. [Description of Signs] 1; accelerator pedal, 2; engine, 3; hydraulic pump,
4; hydraulic actuator; 5; control valve; 6; operating lever; 7; operating lever signal output means; 8; valve control signal output section; 9; accelerator signal output means; 10; operating lever response switching range upper limit setting means; X2: saturation switching amount at low engine speed (FIG. 2); Y1 to Y2; stepwise or continuous by operating lever response switching range upper limit setting means 10 The upper limit of the operation lever response switching area changed to (a): a: lever operation signal, b1, b2: valve control signal, c: accelerator signal, d: operation lever response switching area upper limit setting means,

Claims (1)

1. An engine 2 whose rotation speed can be arbitrarily controlled between a low rotation speed and a high rotation speed by operating an accelerator pedal 1, and a hydraulic pump 3 driven by the engine 2. And the hydraulic pump 3 to the hydraulic actuator 4
A control valve for controlling the control valve 5 of the hydraulic working machine, comprising: a control valve 5 for controlling a supply amount of hydraulic oil from the control lever; and an operation lever that outputs an operation lever signal a in response to operation of the operation lever 6. Signal output means 7 ・ the accelerator pedal 1 being linked to the accelerator pedal 1
Accelerator signal output means 9 for outputting an accelerator signal c in response to the operation of the control valve 5. The upper limit of the control valve 5 spool switchable area by the operation lever signal a is set to the total amount of the oil discharged from the hydraulic pump 3 at the low rotation speed of the engine 2. Control valve 5 that is necessary and sufficient to supply the hydraulic actuator 4 with an operating lever response control range upper limit setting signal for outputting an operating lever response control range upper limit setting signal d for setting to an arbitrary value equal to or less than the spool switching amount. Means 10, a valve control signal b for receiving signals a, c, d from the means 7, 9, 10 to switch and control the control valve.
1, a valve control signal output unit 8 for outputting b2,
The valve control signal output unit 8 controls the switching of the control valve 5 spool within the operation lever response switching area defined by the operation lever response switching area upper limit setting signal d based on the operation lever signal a. The control valve 5 is configured to generate and output the valve control signals b1 and b2 so that the switching control of the control valve 5 spool exceeding the operation lever response switching area defined by the switching area upper limit setting signal d is performed in response to the accelerator signal c. A control device for a control valve of a hydraulic working machine, comprising: