JP2914730B2 - Work machine operation control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling operations of a construction machine, a working machine, or the like having a remote control type control system.

[Conventional technology]

FIG. 8 is a diagram showing a cross section of a main part of a hydraulic remote control valve (hereinafter, referred to as a remote control valve). In general, push rods 3a are radially arranged in four directions around operation lever 2a at equal intervals. , The hydraulic signal generating means 4a is disposed, and by tilting the operating lever 2a forward, backward, left, or right, one or two push rods 3a are pushed down, and only the movement amount thereof, The hydraulic signal generating means 4a corresponds to the amount corresponding to the tilt angle and direction of the operation lever.
Since the built-in spring is compressed, the reaction force increases, and the pressure oil of the hydraulic source 6a flows into the hydraulic signal port 10a until a pressure corresponding to the increased repulsion is generated. .

On the other hand, from the state where the signal pressure is held at the hydraulic signal port 10a, the operation lever 2a returns to the neutral direction, and when the repulsive force of the spring built in the hydraulic signal generating means 4a decreases, the hydraulic signal port 10a is connected to the tank port 7a. In communication, the signal pressure is decreasing.

FIG. 9 is a diagram showing a hydraulic system diagram of hydraulic signal generating means 4a, 4a 'arranged in the left-right direction of the operation lever 2a. The signal pressure in proportion to the angle at which the operation lever 2a is tilted left and right is controlled by a pilot line. 8a and 8a '. Tenth
FIG. 9 is a diagram showing the relationship between the operating lever stroke S and the signal pressure Pi in the proportional hydraulic signal generating means 4a or 4a 'in FIG. 9. This characteristic is used to control, for example, the opening degree of a hydraulic switching valve. Remote control such as is performed.

Next, FIG. 11 is a cross-sectional view of a main part of a device that generates an electric signal proportional to the tilt angle of the operation lever 2b.
As with the remote control valve described above, 4
In the direction, a push rod 3b and a proportional electric signal generating means 5a interlocked with the push rod 3b are radially arranged, which is a so-called joystick. An example of a constituent symbol of the proportional electric signal generating means 5a is constituted by a potentiometer as shown in FIG. 12, and when the operating lever 2b is operated in a certain direction, one or two push rods 3b in that direction are operated.
Moves downward, and changes the internal electric resistance at the contact point interlocked therewith, thereby causing a change in the electric signal. As shown in FIG. 13, the signal voltage Ei increases in proportion to the operation lever stroke S as shown in FIG. 13. However, it is naturally easy to make the characteristic decrease Ei.

[Problems to be solved by the invention]

As described above, the hydraulic signal generating means 4a or 4a 'for remote control and the electric signal generating means 5a are only separate products in the related art, and require a strong operating force in a remote control system. The above-mentioned remote control valve is mainly used for control, and the joystick is used for so-called mechatronic control that issues a command as a new electric signal that takes into account the operation lever stroke and the electric signal detected from the operation and state of a certain part. doing.

However, in a working machine, for example, a hydraulic excavator, there is a case (not shown) in which it is desired to perform control by simultaneously applying a pilot signal pressure and an electric signal voltage to a control system of an operation control device. However, as shown in FIG. 10, the shape of the characteristic curve E indicating the relationship between the operation lever stroke S of the remote control valve and the pilot signal pressure Pi is bent. Further, as shown in FIG. 13, the shape of the characteristic curve showing the relationship between the operation lever stroke S of the joystick and the electric signal voltage Ei is linear. Therefore, when the pilot signal pressure Pi and the electric signal voltage Ei are applied to the control system synchronously, perfect matching cannot be obtained, and the control effect cannot be sufficiently exhibited.

[Means for solving the problem]

As a means for solving the above problems, the present invention
An operating lever, a hydraulic signal generating means for generating a hydraulic signal corresponding to the operating amount of the operating lever, and an electric signal corresponding to the operating amount of the operating lever separately from the hydraulic signal generated by the hydraulic signal generating means And a characteristic curve indicating a relationship between an operation amount of the operation lever and a hydraulic signal generated by the hydraulic signal generation unit, and an operation amount of the operation lever and an electric signal generated by the electric signal generation unit. And a characteristic curve indicating a relationship with the electrical signal to be generated (claim 1).

The electric signal generating means includes: a resistance unit that connects at least a plurality of electric resistances having different resistance values; and contact means that moves in accordance with the operation amount of the operation lever and slidably contacts the resistance unit. And a resistance portion having at least a plurality of electric resistances having different resistance values arranged in parallel, and a plurality of the plurality of electric resistances, each of which moves in accordance with an operation amount of the operation lever. A plurality of variable resistors each including a plurality of contact means slidably in contact with each of the electrical resistors; and a high potential difference setting unit to which a plurality of electrical signals generated by a potential difference before and after the plurality of variable resistors are input. It is preferable that the high potential difference setting means generates an electric signal having a characteristic in which the plurality of electric signals are selected at a high level (claim 3).

In the apparatus according to claim 2 or 3, the hydraulic signal generating means is a pilot valve having a spool that can be linked to a push rod that moves in accordance with the operation amount of the operation lever, and the push rod has By fixing the contact means, more excellent effects as described below can be obtained (claim 4).

[Operation] According to the device of the first aspect, the characteristic curves of the hydraulic signal and the electric signal that are individually generated corresponding to the operation amount of the common operation lever substantially match each other. Can be matched with each other based on
The control effect can be sufficiently exhibited.

Further, according to the device described in claim 2 and the device described in claim 3, it is possible to obtain the characteristics of the electric signal in accordance with the characteristics of the hydraulic signal by only taking out the electric signal proportional to the operation amount of the operation lever. Can be.

According to the device described in claim 4, the contact means of the variable resistance is fixed to the push rod for moving the spool of the pilot valve in accordance with the operation amount of the operation lever.
With a simple configuration, the hydraulic signal and the electric signal can be simultaneously taken out and these signals can be applied to the control system.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a main part circuit diagram showing an operation control device 1 according to a first embodiment of the present invention. In the figure, 2 is a remote control valve for remote control, 3 is an operation lever of the remote control valve 2,
4 is a cam integrated with the operating lever 3; 5 is a pivot pin for supporting the cam 4; 6, 6 'are pilot valves, 7, 7' are push rods of pilot valves 6, 6 ', respectively; The electrical signal generators 9 and 9 'of the control device 1 are variable resistor resistors formed by connecting an electrical resistor a and an electrical resistor b in series, 25 is a brush which is a contact means of the variable resistor,
10, 11, 12, 10 ', 11', 12 'are connection terminals, 13 is a pilot pump, 14 is a hydraulic actuator, for example, an arm cylinder, 15 is a pilot switching valve for controlling the arm cylinder 14, 16, 16' Are pilot switching valves 15
Pilot pressure receiving part, 17 is a main pump, 18 is a tank, P is a pilot pressure introduction port, T is a tank port,
Z and Z 'are pilot pressure derivation ports, respectively. A potential difference (voltage) is set between the connection terminals 11 and 12 and between the connection terminals 11 'and 12'. Second
FIG. 3 is a table showing a signal characteristic curve of an electric signal output from the electric signal generator 8 in FIG. 1. FIG. 3 is a vertical sectional view of a main part of the remote control valve 2 in FIG. In the figure, 19 is the valve element of the remote control valve 2, and 20 is the pilot valve 6
Is a vertical center line of the remote control valve 2.

 FIG. 4 is a sectional view taken along line XX of FIG.

In the figure, reference numeral 21 denotes an insulator that moves together with the push rod 7, and reference numeral 22 denotes a main body of the insulator 21. On the inner surface of the main body 22, there are a resistance element 23 electrically insulated from each other and a conductor 24 parallel to the resistance element 23. The resistance element 23 and the conductor 24
The brush 25 is fixed to the side surface of the insulator 21 so as to simultaneously contact with and slide in the longitudinal direction. Then, both ends of the resistance element 23 and the conductor 24 are connected to connection terminals 10 (not shown in FIG. 4), 11, and 12, respectively.

Next, an operation control method of the hydraulic excavator and the operation control device 1 of the first embodiment will be described with reference to FIGS. Since the variable resistors 9 and 9 'are provided symmetrically to each other, only the variable resistor 9 will be described.

When the operation lever 3 is operated in the direction A from the neutral position, the push rod 7 is pushed downward. The brush 25 moves in conjunction with the push rod 7. When the operating lever 3 is operated from the stroke S1 to SK, the brush 25 slides from the position G of the electric resistance a to the position H. Therefore, it is possible to take out an electric signal that varies proportionally between the connection terminals 11 and 10. The signal characteristic of the electric signal at that time is indicated by a straight line in FIG. When the operating lever 3 is further operated from the stroke SK to S2, the brush 25 slides and moves along the electric resistance b from the connection position H between the electric resistances a and b,
Re-position is reached. Therefore, the signal characteristics of the electric signal taken out between the connection terminals 11 and 10 are as follows.
It changes to a straight line after exceeding SK. As a result, the signal characteristic curve of the electric signal taken out between the connection terminals 11 and 10 is formed in a V-shape as shown in FIG. 2, and the signal characteristic curve E of the pilot pressure derived from the pilot valve 6 (operation in FIG. (Between lever strokes S1 and S2). Therefore, when the operating lever 3 is operated, the pilot signal pressure Pi and the electric signal voltage Ei that are perfectly matched can be synchronously applied to the control system of the hydraulic excavator.

FIG. 5 is a main part circuit diagram of a hydraulic shovel equipped with the operation control device 1 of the present invention. In the figure, reference numeral 26 denotes a work attachment of a hydraulic shovel 27 denotes an arm in the work attachment 26, 14a denotes a head side oil chamber of the arm cylinder 14, 14b denotes a rod side oil chamber, 28 denotes an engine, 29 denotes an engine speed detector, 30 Is the controller, 31 is the controller 30
And 32, a variable slow return valve provided with an electrohydraulic converter 33 as an additional control system. When the operation lever 3 is operated, the pilot hydraulic signal derived from the remote control valve 2 acts on the pilot switching valve 15, so that the pilot switching valve 15 performs a switching operation. At the same time, the electric signal from the electric signal generator of the remote control valve 2 is
30 is input to the calculation unit 31. The controller 30 judges,
A signal is output from the electro-hydraulic converter 32 to the variable throttle valve of the slow return valve 33. Since the signal characteristics of the pilot hydraulic signal generated when the remote control valve 2 is operated and the signal characteristics of the electric signal match, the switching opening of the pilot switching valve 15 and the variable throttle effect of the slow return valve 33 are perfectly matched. I do. Therefore, for example, when an overload is applied to the tip of the work attachment 26 during the operation of the hydraulic excavator, the pump supply oil amount can accurately follow the extension operation of the arm cylinder 14 to prevent cavitation of the arm cylinder 14. it can.

Next, FIG. 6 is a main part circuit diagram showing an operation control device 40 according to a second embodiment of the present invention. In the drawing, components using the same components as those of the operation control device 1 of the first embodiment are denoted by the same reference numerals. 41 is a remote control valve, 42 is an operation control device 40
The electric signal generators 43 and 43 'each have an electric resistance a'
And a variable resistor formed by connecting the resistance b ′ in parallel with
Reference numerals 44, 44 'denote high potential difference setting devices for selecting a high potential difference from a plurality of inputted high / low potential differences.

FIG. 7 is a table showing a signal characteristic curve of an electric signal output from the high potential difference setting device 44 in FIG.

Next, an operation control device 40 according to a second embodiment will be described with reference to FIGS. Since the variable resistors 43 and 43 'are provided symmetrically to each other, only the variable resistor 43 will be described.
A set constant voltage is applied between the high potential difference setting device 44 and the connection terminal 12. When the operation lever 3 is operated in the direction a from the neutral position, the push rod 7 is pushed downward. The brushes 45 and 46 move in conjunction with the push rod 7. When the operation lever 3 is operated from the stroke S1 to the stroke S2, a plurality of potential differences act on the high potential difference setting device 44 due to the sliding movement of the brushes 45 and 46. Electric resistance a '
And the signal characteristic of the electric signal generated through the brush 45 is
In FIG. 7, the signal characteristics of the electric signal generated via the straight line o 'and the electric resistance b' and the brush 46 are expressed by a linear warp.
Wa '. The two straight lines O 'and W' are set so that they cross each other when the operating lever 3 is operated to the stroke SK. Accordingly, the signal characteristic curve of the electric signal selected by the high potential difference setting device 44 is represented by a rectangular O-shaped curve in FIG.
It becomes a w curve. Therefore, the second embodiment of the operation control device 40
In this case, the same operation and function as those of the operation control device 1 of the first embodiment are exhibited.

〔The invention's effect〕

In the conventional operation control device, the characteristic curves of the hydraulic signal and the electric signal that are individually generated according to the operation of the common operation lever are completely different. Therefore, if the hydraulic signal and the electric signal are applied to the control system, for example, synchronously, perfect matching cannot be obtained, and the control effect cannot be sufficiently exerted.

However, in the operation control device according to the present invention, the characteristic curve of the electric signal generated in response to the operation of the operation lever,
The characteristic curve of the hydraulic signal generated in response to the operation of the same operation lever is substantially matched. As a result, the hydraulic signal and the electric signal, which are completely matched, act synchronously and completely on the control system of the work machine, and an accurate control effect can be sufficiently exhibited.

[Brief description of the drawings]

FIG. 1 is a main part circuit diagram showing an operation control device according to a first embodiment of the present invention, FIG. 2 is a signal characteristic curve diagram of an electric signal output from an electric signal generator in FIG. 1, and FIG. FIG. 4 is a longitudinal sectional view of a main part of the remote control valve in FIG.
FIG. 5 is a cross-sectional view taken along line XX of FIG. 5, FIG. 5 is a main part circuit diagram of a hydraulic shovel equipped with the operation control device of the present invention, FIG. 6 is a main part circuit diagram of a second embodiment operation control device of the present invention, FIG. 7 is a signal characteristic curve diagram of an electric signal outputted from the high potential difference setting device in FIG. 6, FIG. 8 is a sectional view of a main part of a conventional hydraulic remote control valve, and FIG. Hydraulic system configuration diagram, FIG. 10 is a characteristic diagram of the hydraulic signal of the remote control valve,
FIG. 11 is a sectional view of a main part of a conventional joystick, FIG. 12 is a configuration diagram using the symbols in FIG. 11, and FIG. 13 is a characteristic diagram of electric signals of the joystick. 1,40… Operation controller 2,41… Remote control valve 3,2a, 2b… Operation lever 6,6 ′… Pilot valve 8,42 …… Electrical signal generator 9,9 ′, 43,43 ′ …… Variable resistance 15 …… Pilot switching valve 25,45,46 …… Brush 44,44 '…… High potential difference setting device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-234906 (JP, A) JP-A-56-97604 (JP, A) JP-A-2-213528 (JP, A) JP-A-64 10566 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) E02F 9/20 F term 3J070

Claims (4)

(57) [Claims] 1. An operating lever, a hydraulic signal generating means for generating a hydraulic signal corresponding to an operating amount of the operating lever, and a hydraulic signal generated by the hydraulic signal generating means corresponding to an operating amount of the operating lever separately from the hydraulic signal generated by the hydraulic signal generating means. And a characteristic curve indicating a relationship between an operation amount of the operation lever and a hydraulic signal generated by the hydraulic signal generation unit, an operation amount of the operation lever and the electric signal. A control device for a work machine, wherein a characteristic curve indicating a relationship with an electric signal generated by a signal generating means is substantially matched. 2. The electric signal generating means according to claim 1, wherein said electric signal generating means is connected to at least a plurality of electric resistances each having a different resistance value, and said electric signal generating means is movable and slidable in accordance with an operation amount of said operation lever. 2. The control device for a working machine according to claim 1, further comprising a variable resistor including a contact means that contacts the contact. 3. An electric signal generating means, comprising: a resistance portion having at least a plurality of electric resistances having different resistance values arranged side by side; A plurality of variable resistors formed by a plurality of contact means slidably contacting the plurality of variable resistors; and a high potential difference setting means to which a plurality of electric signals generated by a potential difference before and after the plurality of variable resistors are input. 2. The control device for a work machine according to claim 1, wherein the potential difference setting means generates an electric signal having a characteristic obtained by selecting the plurality of electric signals at a high level. 4. The hydraulic signal generating means is a pilot valve having a spool that can be linked to a push rod that moves in accordance with the operation amount of the operation lever, and the contact means is fixed to the push rod. The control device for a work machine according to claim 2 or 3, wherein: