JPH082728Y2 - Electric joystick device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an electric joystick device used for controlling a hydraulic control valve in a construction machine such as a hydraulic excavator or a crane.

(Prior Art) An operation lever supported so as to be tiltable in an arbitrary direction around a fulcrum, and a first voltage that outputs a voltage according to a tilt angle of the operation lever in a predetermined direction (hereinafter referred to as “X-axis direction”)
In the electric joystick device having a potentiometer of No. 2 and a second potentiometer that outputs a voltage according to a tilt angle of the operation lever in a direction orthogonal to the X-axis direction (hereinafter referred to as "Y-axis direction"), each potentiometer is conventionally provided. As the contact type, a contact type in which a contact element slides on a resistor is used. An example of the conventional electric joystick device is disclosed in Japanese Utility Model Laid-Open No. 62-183242.

(Problems to be Solved by the Invention) In the above conventional device, as each potentiometer, a contact type in which a contact element slides on a resistor is used, and therefore the resistor may be worn or disconnected, Due to this, noise was superimposed on the output, or it became unusable due to disconnection.

Also, for example, when applying a voltage of 10 V to both ends of the resistor, it is necessary to adjust the output to 5 V at the neutral position of the operating lever, but this adjustment is a fine adjustment of the potentiometer mounting position. Since it was done by doing, adjustment work was troublesome. More specifically, as shown in FIG. 8, for example, the mounting bolts 54 are inserted into the arc-shaped long holes 53 formed in the pair of flanges 52 projecting from the potentiometer 51, and the operation lever is neutralized. Position, move the potentiometer 51 slightly in the direction of the arrow so that the output is 5 volts, and in that state the mounting bolt 54
Therefore, the work of fixing it was necessary. Moreover, not only is this work troublesome, but if the potentiometer 51 is moved while the mounting bolt 54 is screwed, the
I had to find a position where the bolt output could be obtained.

(Means for Solving the Problems) In order to solve the above problems, an electric joystick device of the present invention is provided with an operating lever that is supported so as to be tiltable in an arbitrary direction around a fulcrum, and an inclination of the operating lever in a predetermined direction. An electric joystick device having a first potentiometer for outputting a voltage according to an angle and a second potentiometer for outputting a voltage according to an inclination angle of the operation lever in a direction orthogonal to the predetermined direction, wherein each potentiometer is provided. A magnet that moves according to the inclination of the operating lever, and a pair of magnetoresistive effect elements whose resistance values change due to the movement of the magnet,
Also, the first and second amplifier circuits for amplifying the outputs of the respective potentiometers and the amplification factors of the respective amplifier circuits are adjusted by using a structure in which an output is extracted from the connection point between the pair of magnetoresistive effect elements. The first and second amplification factor adjusting means and the first and second level adjusting means for adjusting the output level of each amplifier circuit are provided.

(Operation) The magnets of the first and second potentiometers move according to the tilt angles of the operation levers in the X and Y axis directions, and the resistance values of the magnetoresistive effect elements of each pair change to change the first and second The output voltage of the second potentiometer changes. The output voltages of the first and second potentiometers are amplified by the first and second amplifier circuits and output as a final output signal. At this time
The amplification factors of the first and second amplification circuits are adjusted by the first and second amplification factor adjustment means, and the first and second level adjustment means are used to adjust the first and second amplification factors.
The output level of the second amplifier circuit is adjusted.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

FIG. 6 is a vertical sectional front view of an electric joystick device according to an embodiment of the present invention, and FIG. 7 is a transverse plan view of the same, in which a central portion of an operating lever 3 is supported on a ceiling wall of a casing 1 via a universal bearing 2. The operation lever 3 can be tilted in any direction by a predetermined angle. Inside the casing 1, a substantially U-shaped first arm 4 and a second arm 5 are arranged, and the first arm 4 is a horizontal axis along the Y-axis direction (vertical direction in FIG. 7). The second arm 5 is rotatable around the core.
Is rotatable about a horizontal axis along the X-axis direction (left-right direction in FIG. 7). That is, the first arm 4 has one end rotatably supported by the pin 6 penetrating the side wall of the casing 1 and is attached to the outer surface of the side wall of the casing 1.
The other end is fixed to an input shaft 8 which projects from the potentiometer 7 and penetrates the side wall of the casing 1 and is rotatable by a predetermined angle. The second arm 5 has one end rotatably supported by a pin 9 penetrating the side wall of the casing 1 and projects from the second potentiometer 10 attached to the outer surface of the side wall of the casing 1 so that the side wall of the casing 1 can be opened. The other end is fixed to the input shaft 11 which penetrates and is rotatable by a predetermined angle. The first arm 4 and the second arm 5 are provided with long holes 12 and 13 along the longitudinal direction, respectively, and the lower end of the operating lever 3 penetrates both the long hole 12 and the long hole 13. ing. Therefore, if the operating lever 3 is tilted in an arbitrary direction, the input shaft 8 of the first potentiometer 7 is rotated according to the tilt angle of the operating lever 3 in the X-axis direction, and the operating lever 3 is tilted in the Y-axis direction. The input shaft 11 of the second potentiometer 10 rotates according to the angle. An amplifier board 15 is attached to the outer surface of the side wall of the casing 1 via a plurality of brackets 14 made of an insulator, and an amplifier circuit and the like described later are mounted on the amplifier board 15. The amplifier board 15 may be installed inside the casing 1. The operating lever 3 is urged by a spring (not shown) so as to maintain the neutral position shown.

FIG. 1 is a circuit diagram of an electric joystick device according to an embodiment of the present invention. The first potentiometer 7 and the second potentiometer 10 are a pair of magnetoresistive effect elements.
MR1 and MR2 and a magnet MG that moves in the direction of the arrow in FIG. 1 as the input shafts 8 and 11 rotate.
The resistance value of 2 changes. The amplifier board 15 includes a first amplifier circuit 18 for amplifying the output voltage of the first potentiometer 7.
A second amplifier circuit 19 for amplifying the output voltage of the second potentiometer 10, a trimmer 20 as a first gain adjusting means for varying the gain of the first amplifier circuit 18, and a second amplifier. A trimmer 21 as second amplification factor adjusting means for varying the amplification factor of the circuit 19, a trimmer 22 as first level adjusting means for varying the output level of the first amplification circuit 18,
A trimmer 23 as a second level adjusting means for varying the output level of the second amplifier circuit 19 is mounted, the trimmers 20 and 22 are connected to the first amplifier circuit 18, and the trimmers 21 and 23 are the first. 2 is connected to the amplifier circuit 19. One end of the magnetoresistive effect element MR1 of the first and second potentiometers 7, 10 is connected to the power supply terminal 24, and the first, second potentiometer 7,
One end of the magnetoresistive effect element MR2 of 10 is connected to the ground terminal 25. The other end of the magnetoresistive effect element MR1 of the first and second potentiometers 7 and 10 is connected to the other end of the magnetoresistive effect element MR2. The connection point between the other end of the magnetoresistive effect element MR1 and the other end of the magnetoresistive effect element MR2 of the first potentiometer 7 is connected to the input end of the first amplifier circuit 18, and The output end is connected to the X-axis side output terminal 26. Magnetoresistive element MR1 of the second potentiometer 10
Is connected to the other end of the magnetoresistive effect element MR2 by the second
Is connected to the input end of the amplifier circuit 19 and the output end of the second amplifier circuit 19 is connected to the Y-axis side output terminal 27.

Next, the operation will be described. When the operation lever 3 is tilted in an arbitrary direction against the biasing force of a spring (not shown), the first arm 4 rotates about the pin 6 and at the same time, the second arm 5 rotates about the pin 9. Rotate. Here, the rotation angle of the first arm 4 corresponds to the inclination angle of the operation lever 3 in the X-axis direction, and the input shaft 8 of the first potentiometer 7 is provided.
Rotate integrally with the first arm 4. Therefore, the magnet MG of the first potentiometer 7 moves in the arrow direction of FIG. 1 according to the tilt angle of the operation lever 3 in the X-axis direction,
The resistance values of the magnetoresistive effect elements MR1 and MR2 change. Similarly, the rotation angle of the second arm 5 corresponds to the tilt angle of the operation lever 3 in the Y-axis direction, and the second potentiometer
The input shaft 11 of 10 rotates integrally with the second arm 5. Therefore, depending on the tilt angle of the operation lever 3 in the Y-axis direction, the second
The magnet MG of the potentiometer 10 moves in the direction of the arrow in FIG. 1, and the resistance values of the magnetoresistive effect elements MR1 and MR2 change.

Since the magnetoresistive effect element MR1 and the magnetoresistive effect element MR2 of the first potentiometer 7 are inserted in series between the power supply terminal 24 and the ground terminal 25, the magnetoresistive effect element MR1
A voltage obtained by dividing the power supply voltage applied to the power supply terminal 24 by the resistance value of the magnetoresistive effect element MR1 and the resistance value of the magnetoresistive effect element MR2 is output to the connection point between the magnetoresistive effect element MR2 and the magnetoresistive effect element MR2. . This voltage is input to the input terminal of the first amplifier circuit 18, amplified by the first amplifier circuit 18, and output to the X-axis side output terminal 26. Therefore, a signal of a voltage corresponding to the tilt angle of the operating lever 3 in the X-axis direction is output to the X-axis side output terminal 26. Similarly, the second potentiometer 10
Since the magnetoresistive effect element MR1 and the magnetoresistive effect element MR2 are inserted in series between the power supply terminal 24 and the ground terminal 25, the connection point between the magnetoresistive effect element MR1 and the magnetoresistive effect element MR2 is A voltage obtained by dividing the power supply voltage applied to the power supply terminal 24 by the resistance value of the magnetoresistive effect element MR1 and the resistance value of the magnetoresistive effect element MR2 is output. This voltage is input to the input terminal of the second amplifier circuit 19, amplified by the second amplifier circuit 19, and output to the Y-axis side output terminal 27. Therefore, the Y-axis output terminal 27 outputs a voltage signal corresponding to the tilt angle of the operating lever 3 in the Y-axis direction.

By the way, the power supply voltage applied to the power supply terminal 24 is, for example,
Assuming that the voltage is 10 volts, the inclination angle of the operating lever 3 in the X and Y axis directions and the output voltage of the first and second potentiometers 7 and 10, that is, the input voltage of the first and second amplifier circuits 18 and 19 The relationship is as shown in FIG. That is, the output voltage of the first and second potentiometers 7 and 10 changes within a range of 4 to 6 volts with respect to the inclination of the operation lever 3 from one stroke limit to the other stroke limit in the X and Y axis directions. To do. This voltage change width of 2 volts is too small with respect to the power supply voltage of 10 volts, so that the output voltages of the first and second potentiometers 7 and 10 are amplified by the first and second amplifier circuits 18 and 19. However, at this time, the trimmers 20 and 21 cause the first and second amplifier circuits 1 to
By adjusting the amplification factor of 8,19, the difference between the maximum value and the minimum value of the voltage obtained at the X-axis side output terminal 26 and the Y-axis side output terminal 27 is 8
Make it a bolt. That is, as shown in FIG.
The inclination of the input / output characteristics of the first and second amplifier circuits 18 and 19 is adjusted so that the change of the output voltage due to the inclination of the operating lever 3 becomes 8 volts. In addition, the trimmer 22,2
The output levels of the first and second amplifier circuits 18 and 19 are adjusted by 3 and the voltage obtained at the X-axis side output terminal 26 and the Y-axis side output terminal 27 becomes 5 volts when the operating lever 3 is in the neutral state. To do so. That is, as shown in FIG. 4, the operating lever 3 is kept in the neutral position, and the levels of the input / output characteristics of the first and second amplifying circuits 18 and 19 are adjusted so that the output voltage becomes 5 volts. Of. As a result of these adjustments, as shown in FIG. 5, the voltage that changes from 1 to 9 volts depending on the tilt angle of the operation lever 3 in the X and Y axis directions and that becomes 5 volts at the neutral position of the operation lever 3 is X. It is available at the shaft side output terminal 26 and the Y axis side output terminal 27.

In this way, the non-contact type first and second potentiometers
Since 7 and 10 are used, the resistance of the potentiometer will not be worn or broken, and noise will not be superimposed on the output or become unusable unlike the conventional device, extending the life and improving the reliability at the same time. realizable.

Further, unlike the conventional device, it is not necessary to adjust the position of the potentiometer and the output can be adjusted by the trimmers 20 to 23, so that the adjustment work is easy.

Further, the output voltages of the first and second potentiometers 7 and 10 are amplified by the first and second amplifying circuits 18 and 19, and the first and second potentiometers are provided.
The gain and output level of the amplifier circuits 18 and 19 of the
~ 23 to adjust the final output, so the first, second
It is possible to correct variations in resistance values of the potentiometers 7 and 10, and improve the compatibility of the electric joystick device.

Further, by setting the final output voltage to change within a range smaller than the range from 0 volt to the power supply voltage in accordance with the tilt angle of the operating lever 3, it is possible to detect the occurrence of the disconnection and to detect the occurrence of the disconnection. It is easy to identify broken points,
The process at the time of abnormality can be performed quickly and surely, and the reliability is improved. That is, as in the embodiment, with respect to the power supply voltage of 10 V, the X-axis side output terminal 26 is set in accordance with the tilt angle of the operating lever 3.
And if the voltage obtained at the Y-axis side output terminal 27 is set to change from 1 volt to 9 volts, for example, when the wiring connected to the power supply terminal 24 or the X-axis side output terminals 26, 27 is broken, X, Y When the voltage of the shaft side output terminals 26, 27 becomes 0 volt and the wiring connected to the ground terminal 25 is broken, X, Y
Since the voltage of the shaft-side output terminals 26, 27 becomes 10 V, it is possible to easily know the occurrence of disconnection and the location of the disconnection.

(Other Embodiment) In the above embodiment, the power supply voltage is supplied from the common power supply terminal 24 to the first potentiometer 7 and the second potentiometer 10, but the present invention has such a structure. The present invention is not limited to this, and different power supply voltages may be supplied to the first potentiometer 7 and the second potentiometer 10.

Further, in the above embodiment, the trimmers 20 and 21 are used as the first and second amplification factor adjusting means and the trimmer 22.23 is used as the first and second level adjusting means. The present invention is not limited to this, and other elements may be used as the first and second amplification factor adjusting means and the first and second level adjusting means.

(Effects of the Invention) As described above, according to the electric joystick device of the present invention, since the non-contact type first and second potentiometers are used, the resistance of the potentiometer is worn or disconnected like the conventional device. It is possible to extend the life and improve the reliability at the same time without noise being superimposed on the output and becoming unusable. Moreover, unlike the conventional device, there is no need to adjust the position of the potentiometer.
Since the output can be adjusted by changing the input / output characteristics of the first and second amplifier circuits by the first and second amplification factor adjusting means and the first and second level adjusting means, the adjustment work is easy. Is. The output voltage of the first and second potentiometers is amplified by the first and second amplifier circuits, and the amplification factors and output levels of the first and second amplification circuits are adjusted by the first and second amplification factor adjusting means. Also, since the final output is obtained by adjusting by the first and second level adjusting means, it is possible to correct variations in the resistance value of the magnetoresistive effect elements in the first and second potentiometers and the like, and the electric joystick device. The compatibility of can be improved. Also, by setting the final output voltage to change within a range smaller than the range from 0 volt to the power supply voltage according to the tilt angle of the operating lever, it is possible to detect the occurrence of disconnection and identify the location of disconnection when the wiring is disconnected. This makes it easier to perform processing in the event of an abnormality, and improves reliability.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an electric joystick device according to an embodiment of the present invention, and FIG. 2 is a tilt angle of an operating lever and
Explanatory diagram of the relationship with the output voltage of the second potentiometer,
FIG. 3 is an explanatory diagram of changes in output characteristics due to adjustment of amplification factors in the first and second amplifier circuits, and FIG. 4 is explanatory diagram of changes in output characteristics due to adjustment of output levels in the first and second amplifier circuits. 5 and 5 are explanatory views of the relationship between the tilt angle of the operating lever and the output voltage of the first and second amplifier circuits, and FIG. 6 is a vertical sectional front view of the electric joystick device according to one embodiment of the present invention. FIG. 7 is a cross-sectional plan view of the same, and FIG. 8 is an explanatory view of position adjustment work of a conventional electric joystick device. 3 ... operating lever, 7 ... first potentiometer, 10
...... Second potentiometer, 18 …… First amplifier circuit,
19 ... Second amplification circuit, 20 ... Trimmer (first amplification factor adjusting means), 21 ... Trimmer (second amplification factor adjusting means), 22
...... Trimmer (first level adjusting means), 23 ...... Trimmer (second level adjusting means), MR1, MR2 ...... Magnetoresistive element, MG ...... Magnet

Claims (1)

[Scope of utility model registration request] 1. An operating lever supported so as to be tiltable in an arbitrary direction around a fulcrum, a first potentiometer for outputting a voltage according to an inclination angle of the operating lever in a predetermined direction, and the operating lever. In an electric joystick device having a second potentiometer that outputs a voltage according to a tilt angle in a direction orthogonal to a predetermined direction, as each of the potentiometers, a magnet that moves according to the tilt of the operation lever, and a movement of the magnet. And a pair of magnetoresistive effect elements whose resistance value changes by
Also, the first and second amplifier circuits for amplifying the outputs of the respective potentiometers and the amplification factors of the respective amplifier circuits are adjusted by using a structure in which an output is extracted from the connection point between the pair of magnetoresistive effect elements. An electric joystick device comprising: first and second amplification factor adjusting means, and first and second level adjusting means for adjusting an output level of each of the amplifier circuits.