JP2003157122A - Electric operation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric operation device which can reduce adverse influence of vibration on a potentiometer. SOLUTION: The device is provided with a support shaft 13 provided integrally to gimbal springs 11A and 11B swinging together with an operation lever 7, an extension arm 12 which is provided integrally to the support shaft 13, and a rotary arm 24 which is provided integrally with the rotary shaft 23, equipped with a torsion coil spring 26 which forms a link part 25 with a long groove 15 provided to the extension arm 12 and a projection 25 provided to the rotary arm 24 and holds the rotary arm 24 at a neutral position, provided with a 1st gap 32 and a 2nd gap between both side parts of the long groove 15 and projection 25 forming the link part 35, provided with a 1st stopper 30 which locks an end part 26a of the spring 26 to a potentiometer body 22, and a 2nd stopper 31 which locks an end part 26b of the spring 26 to the rotary arm 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric operating device which is provided in a construction machine such as a hydraulic excavator and has a potentiometer which outputs an electric signal according to a swing angle of an operating member.

[0002]

2. Description of the Related Art The applicant of the present invention has previously proposed an electric operating device of this type as Japanese Patent Application No. 2001-239531.
The prior art related to the applicant of the present application is provided, for example, in a hydraulic excavator, and an operating member, for example, an operating lever, which is rockably operated by an operator to operate an actuator such as a boom cylinder or an arm cylinder, and an operation of the operating lever. A swinging member including a gimbal, a cam, and the like that swings in accordance with the above, a support shaft that is integrally provided with the swinging member and supports the swinging member, and swings as the swinging member swings. A potentiometer which has a rotation shaft and outputs a rotation angle signal for driving the above-mentioned actuator. Further, the potentiometer is arranged such that its rotation axis is parallel to the support axis of the swing member described above.

The construction and operation of the prior art relating to the applicant of the present application will be described with reference to FIGS.

FIG. 4 is an enlarged view of a main part of an electric operating device which is a prior art proposed by the applicant of the present application, and FIG. 5 is a main part showing a state when the potentiometer provided in the prior art shown in FIG. 4 is in operation. FIG.

The essential structure of the prior art shown in FIG. 4 is provided integrally with a support shaft (not shown) for supporting the above-mentioned swinging member, and an extension arm 12 extending in the direction of the potentiometer 21 and this extension arm. A rotary arm 24 which is engaged with the extension arm 12 so as to be rotatable in a vertical plane parallel to the plane including the rotary region of 12 and is integrally provided on the rotary shaft 23 of the potentiometer 21; , The extension arm 12 and the rotation arm 24 are rotatably connected to each other, and for example, the long groove 15 formed in the extension arm 12 and the rotation arm 24 are provided in the long groove 15 and arranged in the long groove 15.
5 and a link portion 35 formed by a combination with a protrusion 25 that is relatively movable in the extension direction.

In FIG. 4, 1 is a housing forming an outer shell, 4 is a main body for movably supporting a push rod (not shown) provided directly below the swinging member, and 20 is a main body 4.
It is a bracket that is integrally provided on the lower side and to which the main body 22 of the potentiometer 21 is fixed.

In the prior art thus constituted, when an operating lever (not shown) is operated to operate the actuator, the swing member (not shown) swings against the push-up force of the push rod (not shown), and this swing is caused. The extension arm 12 swings as shown in FIG. 5 through the support shaft (not shown) integrally with the swinging of the member, and is provided in the link portion 35, that is, the long groove 15 formed in the extension arm 12 and the rotating arm 24. The rotary arm 24 rotates via the projection 25, and the rotary arm 24 rotates to output a rotary angle signal from the potentiometer 21. The above-mentioned actuator is driven according to this rotation angle signal.

[0008]

In the above-mentioned prior art, as shown in FIG. 4, the width dimension of the long groove 15 formed in the extension arm 12 and the diameter of the projection 25 of the rotating arm 24 are set to be substantially the same. It had been. Therefore, the swing motion of the extension arm 12 is immediately transmitted as the rotary motion of the rotary arm 24 of the potentiometer 21.

Further, an electric operating device of this kind generally causes a manufacturing error, and when the manufacturing error is accumulated, the swing member (not shown) and the head of the push rod (not shown) described above are accumulated. It may happen that a gap is formed between the parts.

On the contrary, in the assembled state, the lower end of the swinging member may give an unnecessary pressing force to the head of the push rod.

When a gap is formed between the swing member and the head portion of the push rod, the swing member can easily swing freely. Along with this, when the operation lever vibrates due to vibration of the vehicle body or the like, the rocking member may vibrate.

Further, in the assembled state in which the lower end of the swinging member exerts an unnecessary pressing force on the head of the push rod as described above, it is held in the original neutral position by the reaction force from the push rod, that is, the pushing force. It can be difficult to do. In such a case, similarly to the above, when the operation lever vibrates due to the vibration of the vehicle body or the like, the rocking member may vibrate.

There is a problem when the rocking member vibrates as described above. That is, the width dimension of the long groove 15 of the extension arm, which is integrally provided on the swing member via the support shaft, and the diameter of the protrusion 25 of the rotating arm 24 are set to be substantially the same, and Since there is almost no gap between the swing arm and the protrusion 25, when the swing member vibrates, the rotary arm 24 also vibrates integrally. When the rotating arm 24 vibrates, the potentiometer 2
There is a concern that a slight vibration may occur at the contact portion with the resistor in No. 1. Therefore, it is desired to develop a technique for suppressing the wear of the resistor due to the slight vibration generated by the potentiometer.

Further, as related to the above, when the vibration width applied to the operation lever becomes large, there is a concern that the influence of the vibration width directly acts on the potentiometer and outputs an unnecessary rotation angle signal. . Therefore, it is also requested to eliminate such concerns.

The present invention has been made in view of the actual situation of this kind of technique, and an object thereof is to provide an electric operating device capable of reducing the adverse effect of vibration on a potentiometer.

[0016]

In order to achieve the above-mentioned object, the present invention provides an operating member which is rockably operated by an operator and drives an actuator, and a rocking motion which is rocked by the rocking of the operating member. A member, a support shaft that supports the swing member, and a rotary shaft that rotates with the swing of the swing member, and a potentiometer that outputs a rotation angle signal for driving the actuator. An extension arm provided integrally with the support shaft and extending in the potentiometer direction, and rotatably engaged with the extension arm in a vertical plane parallel to a plane including a rotation region of the extension arm. In addition, the rotary arm integrally provided on the rotary shaft of the potentiometer, the extension arm and the rotary arm are relatively rotatably connected to each other, and the long groove is disposed in the long groove. of A potentiometer, comprising: a link portion formed of a combination with a protrusion that is relatively movable in the longitudinal direction, wherein the rotation axis of the potentiometer is arranged parallel to the support axis. An elastic member for holding the rotating arm at the neutral position is provided, and at the neutral position, a first member is provided between the long groove of the link portion and both side portions of the protrusion.
It is configured such that a gap and a second gap are provided.

In the present invention thus constructed, when the operating member is operated with the intention of driving the actuator, the extension arm oscillates via the oscillating member and the support shaft, and thus extends through the link portion, that is, the extension. The rotary arm rotates through the long groove of the arm and the protrusion of the rotary arm, and the rotary angle signal can be output from the potentiometer. A corresponding processing operation is performed according to the rotation angle signal, and the actuator can be driven according to the processing operation.

Further, a long groove provided on an extension arm that integrally swings with a swinging member that swings in response to the operation of the operating member, and both side portions of a protrusion that is integrally provided on the rotary shaft of the potentiometer. Since the first gap and the second gap are provided between them, even if the operation member vibrates due to vibration of the vehicle body or the like and the extension arm vibrates via the swing member and the support shaft, the vibration does not occur in the first gap. And, it is possible to suppress the transmission to the rotary arm on the potentiometer side by absorbing it in the second gap. That is, it is possible to suppress the transmission of the vibration applied to the operating member to the contact portion with the resistor in the potentiometer,
It is possible to suppress the generation of microvibration at the contact portion with the resistor.

Further, when setting the first gap and the second gap, by taking into consideration a comparatively large vibration width that can occur when the vehicle body vibrates, the extension arm vibrates with a comparatively large vibration as the vehicle body vibrates. Even when vibrating in the width, the transmission of the vibration to the rotary arm on the potentiometer side can be suppressed.

Further, since the rotating arm is held in the neutral position by the elastic member, the elastic force of the elastic member immediately stabilizes the rotating arm even when the rotating arm vibrates slightly even when the vehicle body vibrates. Can be kept in a neutral position.

As described above, according to the present invention, it is possible to reduce the adverse effects of the vibration of the vehicle body on the potentiometer as much as possible.

In the above invention, the elastic member may be a torsion coil spring.

Further, in the above invention, the potentiometer main body is provided with a first stopper to which one end of both ends of the torsion coil spring is locked, and the rotary arm is provided with both ends of the torsion coil spring. You may make it the structure which provided the 2nd stopper with which the other end part of a part is locked.

With this structure, when the extension arm swings in accordance with the operation of the operating member, one end of the torsion coil spring is locked by the first stopper and
By locking the other end of the torsion coil spring to the second stopper, the torsion coil spring is expanded, resisting the spring force of the torsion coil spring, and rotating the rotating arm via the link portion. The potentiometer outputs a rotation angle signal. By returning the operating member to the neutral position, the rotary arm returns to the neutral position via the extension arm and the link portion, and the torsion coil spring is closed and stably held at the neutral position.

In either case of rotating the rotating arm from the neutral position to the operating position or from the operating position to the neutral position, one end of the torsion coil spring engages with the first stopper. Since the other end is stopped by the second stopper, the spring force of the torsion coil spring presses the protrusion against one edge of the long groove, and the protrusion and the long groove with which the protrusion engages. There is no backlash between the one edges, and a smooth pivoting motion of the pivot arm can be realized without causing hysteresis. That is, it is possible to output a stable rotation angle signal from the potentiometer according to the rotation of the rotation arm associated with the operation of the operation member.

In the above invention, the first gap and the second gap may be set to have the same size.

The electric operating device may be provided in a construction machine.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an electric operating device of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the electric operating device of the present invention, FIG. 2 is an enlarged view taken along the line AA of FIG. 1, and FIG. 3 is provided in the embodiment shown in FIG. It is a principal part enlarged view which shows the state at the time of operation of a potentiometer.

This embodiment is also provided in a construction machine or the like, for example, in a hydraulic excavator such as a mini excavator. As shown in FIG. 1, the operator swings the operation to operate an actuator such as a boom cylinder or an arm cylinder. A member, for example, the operation lever 7, and a pair of gimbals 11A and 11B that swing in accordance with the operation of the operation lever 7 and are arranged in directions orthogonal to each other, and these gimbals 11
A, a swing member including a cam 2 provided integrally with A, 11B, a universal joint 3 that supports the operation lever 7 so as to be swingable in a direction of 360 °, and a support shaft that supports the swing member, such as a gimbal. Support shafts 13 that respectively support 11A and 11B, and bearings 14 for these support shafts 13.
And a rotation shaft 23 that rotates with the swing of the swing member described above.
And a potentiometer 21 that outputs a rotation angle signal for driving the actuator described above.

Two supporting shafts 13 are provided, one on each side of the gimbal 11A, and two supporting shafts 13 are provided, one on each side of the gimbal 11B. There is. Further, one potentiometer 21 is provided in association with one specific support shaft 13 of the two support shafts 13 of the gimbal 11A.
Another potentiometer 21 is provided in association with the two support shafts 13 of 1B. These two potentiometers 21 are arranged so that their phases are different from each other by 90 °.

The potentiometers 21 are arranged so that the respective rotary shafts 23 are located below the corresponding support shafts 13 and are parallel to the corresponding support shafts 13.

Further, the extension arms 12 which are integrally attached to each of the above-mentioned two specific support shafts 13 and extend in the corresponding potentiometer 21 direction, and the rotation regions of the extension arms 12 respectively. Engage with these extension arms 12 so as to be rotatable in a vertical plane parallel to the plane in which the potentiometer 21
Rotation arm 24 integrally provided on each rotation shaft 23 of the
A means for relatively rotatably connecting the extension arm 12 and the corresponding one of the rotary arms 24, for example, a long groove 15 formed in each of the extension arms 12, and provided in each of the rotary arms 24, The link portions 35, which are arranged in the corresponding long grooves 15 and are combined with the projections 25 that are relatively movable in the extension direction of the long grooves 15, are provided.

Further, the main body 4 and the main body 4 are arranged so as to be movable in the vertical direction, and the head of the main body 4 is arranged so as to face the lower surface of the cam 2 described above. In addition, a plurality of push rods 5 that can be moved upward by springs (not shown) and brackets 20 that are connected to the lower portion of the main body 4 and to which the above-described potentiometers 21 are fixed are provided.

The components other than the operating lever 7 among the components described above are arranged in the housing 1.

The components described above are almost the same as the prior art previously proposed by the applicant of the present application.

In this embodiment, in particular, as shown in FIGS. 2 and 3, the rotary arms 24 integrally provided on the respective rotary shafts 23 of the potentiometer 21 are neutralized corresponding to the neutral position of the operation lever 7 described above. An elastic member for holding the position, for example a torsion coil spring 26, is provided. The torsion coil spring 26 is attached to the rotary shaft 23 of the corresponding potentiometer 21, for example.

Further, as shown in FIG.
In the state where each of them is kept at the neutral position, the long groove 15 forming the link portion 35 provided on the corresponding extension arm 12 and the link portion 35 provided on the rotating arm 12 are formed.
Between the two sides of the protrusion 25 forming the first
A gap 32 and a second gap 33 are provided. The first gap 32 and the second gap 33 are set to have the same size, for example. A dimension larger than the gap between the cam 2 and the push rod 5, which is empirically considered to be caused by manufacturing error in setting the dimension, that is, the gap δ between the cam 2 and the head of the push rod 5 shown in FIG. The dimensions of the first gap 32 and the second gap 33 are set so that
Further, the dimensions of the first gap 32 and the second gap 33 are set so as to be larger than the vibration width of the extension arm 12 due to a comparatively large vibration of the vehicle body that can be experienced, for example.

Furthermore, in this embodiment, each potentiometer main body 22 is provided with a first stopper 30 to which one end 26a of both ends of the torsion coil spring 20 is locked. Rotating arm 24
To the other end 26 of the torsion coil spring 26.
A second stopper 31 for locking b is provided.

In the neutral state of the rotating arm 24 shown in FIG. 2, for example, one end 26a of the torsion coil spring 26 is provided.
Are locked to the first stopper 30, and the other end 26 b is locked to the second stopper 31, these torsion coil springs 26, the first stopper 30, and the second stopper 31.
The positional relationship with and the spring shape are set.

In this embodiment having such a configuration, when the operator of the hydraulic excavator grips the operation lever 7 and swings the operation lever 7 in the direction along the plane of FIG. 1, for example, the first gimbal 11A and the corresponding support shaft 13 are provided. , And the cam 2 swing integrally through the universal joint 3, and the support shaft 1
Along with the swing of 3, the corresponding extension arm 12 rotates about the corresponding support shaft 13 as a fulcrum. Along with this, as shown in FIG. 3, the rotating arm 24 rotates in conjunction with the swing of the extending arm 12 through the long groove 15 of the extending arm 12 and the corresponding protrusion 25 of the rotating arm 24. The rotary shaft 23 of the corresponding potentiometer 21 rotates integrally with this.

With the operation of the operation lever 7, the extension arm 1
When 2 swings, one end 26a of the torsion coil spring 26 is locked by the first stopper 30, and
The torsion coil spring 26 is expanded by rotating the rotation arm 24 while the second stopper 31 is locked to the other end 26b of the torsion coil spring 26. Therefore, the rotating arm 24 rotates against the spring force of the torsion coil spring 26.

In this way, the rotation angle signal corresponding to the operation amount of the operation lever 7 in the direction along the plane of FIG. 1 is drawn from the corresponding potentiometer 21, that is, at the lower position of the central portion of FIG. It is output from the potentiometer 21 that is present. A processing operation such as a switching operation of a directional control valve (not shown) is performed according to the rotation angle signal, and a predetermined actuator, for example, a boom cylinder is driven according to the processing operation, and the driving speed thereof is controlled. .

Further, for example, when the operation lever 7 is operated in the direction orthogonal to the paper surface of FIG. 1, the gimbal 11B swings,
The same operation as described above is performed, the potentiometer 21 arranged on the lower right side in FIG. 1 is actuated, the corresponding actuator, for example, the arm cylinder is driven according to the rotation angle signal, and the driving speed thereof is controlled. It

Further, for example, when the operating lever 7 is operated in a direction different from the above-mentioned two directions, for example, in the intermediate direction, the same operation as described above is carried out and the two potentiometers 21 are actuated. A corresponding actuator, for example, a bucket cylinder is driven according to the rotation angle signal, and its driving speed is controlled.

According to the present embodiment configured as described above,
A gimbal 11A that swings with the operation of the operation lever 7,
11B, between the long groove 15 provided in the extension arm 12 that integrally swings with the swinging member including the cam 2 and both sides of the protrusion 25 integrally provided on the rotary shaft 23 of the potentiometer 21. Since the first gap 32 and the second gap 33 shown in FIG. 2 are provided, even if the operation lever 7 vibrates due to vibration of the vehicle body and the extension arm 12 vibrates via the swing member and the support shaft 13, The vibration can be absorbed by the first gap 32 and the second gap 33, and the potentiometer 21
The transmission to the rotating arm 24 on the side can be suppressed.
That is, it is possible to suppress the transmission of the vibration applied to the operation lever 7 to the contact portion with the resistor in the potentiometer 21, and it is possible to suppress the occurrence of the slight vibration at the contact portion with the resistor. As a result, it is possible to suppress wear of the resistor inside the potentiometer 21 due to such slight vibration, and it is possible to improve the durability of the potentiometer 21.

Further, when setting the first gap 32 and the second gap 33, since a comparatively large vibration width which may occur when the vehicle body vibrates is taken into consideration, the extension arm 12 is accompanied by the vibration of the vehicle body. Even when the vibration occurs in a relatively large vibration width, the transmission of the vibration to the rotary arm 24 on the potentiometer 21 side can be suppressed. Therefore, even in such a case, the potentiometer 21
It is possible to suppress the occurrence of microvibration in the internal resistor and the contact portion, suppress the abrasion of the resistor, and improve the durability of the potentiometer 21. In addition, the potentiometer 21
It is possible to prevent an erroneous signal from being generated and to improve the signal output accuracy of the potentiometer 21 in response to the operation of the operation lever 7, which contributes to the improvement of reliability.

Further, since the turning arm 24 is held in the neutral position by the torsion coil spring 26, the turning arm 24 may be slightly moved when the vehicle body vibrates.
Even when the vibration occurs, the rotating arm 24 is immediately kept in a stable neutral position by the spring force of the torsion coil spring 16,
It is possible to prevent the effective rotation angle signal from being transmitted from the potentiometer 21, and in this respect as well, the potentiometer 21 can be prevented.
The signal output accuracy of can be improved, which contributes to the improvement of reliability.

Further, the potentiometer body 22 is provided with a first stopper 30 to which one end 26a of the torsion coil spring 26 is locked, and the other end 26b of the torsion coil spring 26 is locked to the rotating arm 24. Second stopper 31
Since the rotating arm 24 is rotated from the neutral position to the operating position, and also from the operating position to the neutral position, one end of the torsion coil spring 26 is provided. 26a is retained by the first stopper 30 and the other end portion 26b is retained by the second stopper 31 so that the protrusion 25 causes the spring 25 of the torsion coil spring 26 to move the protrusion 25 to one edge of the long groove 15. And a long groove 15 that is engaged with the protrusion 25 by being pressed against the protrusion.
It is possible to realize a smooth rotation operation of the rotation arm 26 without causing play between the one edge portions and without causing any hysteresis. Therefore, it is possible to output a stable rotation angle signal from the potentiometer 21 according to the rotation of the rotating arm 24 in accordance with the operation of the operation lever 7, and also in this respect, the signal output accuracy of the potentiometer 21 can be improved. Contribute to improving reliability.

In the above embodiment, the first gap 32 and the second gap 33 are set to the same size, but they may be set to different sizes.

In the above, the torsion coil spring 26 is attached to the rotary shaft 23 of the potentiometer 21,
The present invention is not limited to such a configuration, and may be attached to other parts such as the potentiometer main body 22 or the bracket 20.

Further, in the above, the torsion coil spring 26 is provided as an elastic member for holding the rotating arm 24 in the neutral position, but the present invention is not limited to such a configuration, and other spring properties are provided. You may make it provide the member which has.

[0053]

According to the present invention, it is possible to suppress the transmission of the vibration applied to the operating member to the contact portion with the resistor in the potentiometer, and to generate the slight vibration at the contact portion with the resistor. It is possible to suppress the abrasion of the resistor in the potentiometer due to such a slight vibration which has been a concern, and it is possible to improve the durability of the potentiometer.

Further, even when the extension arm vibrates through the operation member with a relatively large vibration width, it is possible to suppress the transmission of such vibration to the rotating arm, and thus, the vibration with a relatively large vibration width is generated. Even in the case where it is given, it is possible to suppress the generation of microvibration in the contact portion with the resistor in the potentiometer, suppress the abrasion of the resistor, and improve the durability of the potentiometer. Also, the generation of false signals from the potentiometer is prevented,
The signal output accuracy of the potentiometer with respect to the operation of the operation member can be increased, which contributes to the improvement of reliability.

Further, even if the rotating arm vibrates slightly even with the vibration applied to the operating member, the elastic force of the elastic member immediately keeps the rotating arm in a stable neutral position, which is effective from the potentiometer. It is possible to improve the signal output accuracy of the potentiometer, which contributes to the improvement of reliability.

Further, in particular, the elastic member is constituted by a torsion coil spring, the main body of the potentiometer is provided with a first stopper to which one end of both ends of the torsion coil spring is locked, and the rotating arm is provided with a torsion coil. In the configuration in which the second stopper that locks the other end of the spring is provided, when the rotating arm rotates from the neutral position to the operating position, and when the rotating arm moves from the operating position to the neutral position. In any case, the protrusion is not pressed against one edge of the long groove by the spring force of the torsion coil spring and does not cause backlash, which allows smooth rotation without any hysteresis. The rotation operation of the arm can be realized. Therefore, a stable rotation angle signal can be output from the potentiometer according to the rotation of the rotation arm associated with the operation of the operation member, and in this respect also, the signal output accuracy of the potentiometer can be increased, and the reliability can be improved. Contribute to.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of an electric operating device of the present invention.

FIG. 2 is an enlarged view taken along the line AA of FIG.

FIG. 3 is an enlarged view of an essential part showing a state when the potentiometer provided in the embodiment shown in FIG. 1 is in operation.

FIG. 4 is an enlarged view of a main part of the electric operating device previously proposed by the applicant of the present application.

5 is an enlarged view of an essential part showing a state when the potentiometer provided in the prior art shown in FIG. 4 is in operation.

[Explanation of symbols]

1 housing 2 Cam (swing member) 3 Universal joint 4 body 5 push rod 7 Operation lever (operation member) 11A 1st gimbal (oscillating member) 11B 2nd gimbal (swing member) 12 extension arm 13 Support shaft 14 bearings 15 Long groove (link part) 20 bracket 21 Potentiometer 22 Potentiometer body 23 rotation axis 24 rotating arm 25 Protrusion (link part) 26 Torsion coil spring (elastic member) 26a One end 26b the other end 30 First stopper 31 Second stopper 32 First gap 33 Second gap 35 Link

Continued front page    (72) Inventor Higashiga ▲ Saki ▼ Mitsuhisa             Hitachi Construction Machinery Co., Ltd.             Ceremony Company Tsuchiura Factory F-term (reference) 2D003 AA01 CA02 DA04 DB04 EA00                 3J070 AA03 AA04 BA09 BA41 BA51                       CB01 CB11 CC61 CC64 CD11                       DA21 EA11

Claims (5)

[Claims] 1. An operating member that is rocked by an operator to drive an actuator, a rocking member that rocks with the rocking of the operating member, a support shaft that supports the rocking member, and the rocking member. A potentiometer that has a rotary shaft that rotates with the swing of the moving member and that outputs a rotary angle signal for driving the actuator; and a potentiometer provided integrally with the support shaft and extending in the potentiometer direction. And an extension arm rotatably engaged with the extension arm in a vertical plane parallel to a plane including a rotation area of the extension arm and integrally provided on a rotation shaft of the potentiometer. The arm, the extension arm, and the rotating arm are relatively rotatably connected to each other, and a combination of an elongated groove and a protrusion disposed in the elongated groove and relatively movable in the extending direction of the elongated groove is formed. In an electric operating device comprising a link portion, the potentiometer being arranged such that its rotating shaft is parallel to the supporting shaft, an elastic member for holding the rotating arm of the potentiometer in a neutral position is provided. An electric operating device, characterized in that, in the neutral position, a first gap and a second gap are provided between the long groove of the link portion and both side portions of the protrusion. 2. The electric operating device according to claim 1, wherein the elastic member is a torsion coil spring. 3. A potentiometer main body is provided with a first stopper to which one end of both ends of the torsion coil spring is locked, and the rotary arm is provided with one of the ends of the torsion coil spring. The electric operating device according to claim 2, further comprising a second stopper to which the other end is locked. 4. The electric operating device according to claim 1, wherein the first gap and the second gap are set to have the same size. 5. The electric operating device according to claim 1, which is provided in a construction machine.