JP2579987Y2 - Operation lever device - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an operation lever device suitable for operating various working machines such as construction machines, and in particular, the value of electric resistance according to the operation amount of the lever. The present invention relates to an operation lever device that outputs an electric signal by changing an operation lever.

[Conventional technology]

When operating a work machine such as a construction machine, the operation is sometimes performed via a lever, and the driving force and the drive amount of the work machine are adjusted by the operation amount of the lever. As a control lever device for controlling such a working machine, a device that detects an operation amount (tilt amount) of a tiltably provided lever with a potentiometer and outputs an electric signal corresponding to the operation amount is often used. (For example, Japanese Utility Model Application Laid-Open No. 62-140636, Japanese Utility Model Application Laid-Open No. 62-183242, Japanese Patent Application Laid-Open No. 63-307701).

That is, for example, when a rotary potentiometer is used as a sensor for detecting the operation amount of the lever, as shown in FIG. 4, the rotation shaft 52 of the potentiometer 50 rotates in conjunction with a lever not shown in FIG. It is supposed to. A wiper 54 is fixed to the rotating shaft 52. When the rotating shaft 52 rotates, the wiper 54 rotates integrally with the rotating shaft 52 as indicated by an arrow 56, and slides on the resistance element R. I do.
A DC power supply 58 is connected between terminals a and b at both ends of the resistance element R.
Are connected, and the terminals c and b connected to the wiper 54 are output terminals, so that an output voltage V _OUT according to the amount of rotation of the wiper 54 (the amount of operation of the lever) can be obtained. I have.

[Problems to be solved by the invention]

However, in the operation lever device using the potentiometer as described above, an operation saturation command may be issued early for the tilting operation of the lever.

In other words, when a rotary potentiometer with an effective electrical angle of 60 degrees is used for a lever whose one-side tiltable angle is 20 degrees,
Generally, the variation of the tiltable angle of the lever is ±
Once, the variation of the effective electrical angle of the potentiometer is 60
± 3 degrees with respect to the degree. For this reason, one side tilt angle 20
The potentiometer 50 with an effective electrical angle of 60 ° ± 3 ° is applied to the lever 20 of ± 1 °, and the resistance element R of the potentiometer 50 is
When a voltage of 5V DC is applied to both ends of the lever and the output voltage when the lever is in the neutral position is adjusted to 2.5V, the relationship between the tilt angle of the lever and the output voltage of the potentiometer is as shown in FIG.

The straight line A in FIG. 5 indicates that the effective electrical angle of the potentiometer is
It shows the characteristic of the output voltage with respect to the tilt angle of the lever of the potentiometer which changes from 60 ° -3 °, that is, from -28.5 ° to + 28.5 °. If the tilt angle of the lever is θ, then A ≒ 0.0877θ + 2.5 [V]... (1) Similarly, a straight line B shows the characteristic of the output voltage with respect to the tilt angle of the potentiometer lever in which the effective electrical angle of the potentiometer changes from −31.5 ° to + 31.5 °, and B ≒ 0.0794θ + 2.5 [V] ... (2) The straight line C in which the effective electrical angle changes from −30.0 ° to + 30.0 ° is C ≒ 0.0833θ + 2.5 [V] (3).

On the other hand, the lever has a tiltable angle of 20 ° ± 1 °,
There is also a lever with a maximum angle (fist stroke) of 19 degrees that can be tilted, and when such a lever is used, the lever is operated to the limit when the lever is tilted +19 degrees or -19 degrees It is necessary to output a saturation signal indicating that At this time, if the potentiometer has the characteristic indicated by the straight line B, the output voltage of the potentiometer that outputs the saturation signal is such that the tilt angle of the lever is +19.
It becomes 4V at the time of degree and 1V at the time of -19 degree.

However, the lever has a full stroke of 21 degrees,
In the case where the potentiometer has a combination having the output characteristic indicated by the straight line A, if the potentiometer outputs a saturation signal when the output voltage is 4 V (or 1 V), the actual tilt angle of the lever from which the saturation signal is output becomes Only +17.1 degrees (or -17.1 degrees), about 81% of the full stroke.

On the other hand, control levers for control of working machines such as construction machines are required to output a saturation command at 95% or more of the full stroke. Therefore, the lever tilt angle ± 1
Considering the variation of the degree and the variation of the effective electrical angle of the potentiometer ± 3 degrees, and the linearity of the potentiometer alone (typically 2-3% for automobiles), the conventional operating lever device has a full stroke of 95%. %, It is difficult to achieve the requirement that a saturation signal be output only when it is equal to or higher than%. Therefore, to satisfy the above requirements,
It is not possible to cope only by improving the accuracy of the lever and the potentiometer, and it is necessary to use a selective combination. Therefore, the assembling work of the operation lever device 10 becomes complicated, and the cost increases.

The present invention has been made to solve the above-mentioned drawbacks of the related art, and has as its object to provide an operation lever device capable of easily improving output accuracy.

[Means for solving the problem]

In order to achieve the above object, an operation lever device according to the present invention includes a lever that tilts in a front-rear direction and / or a left-right direction of a neutral position and that has a maximum stroke of the tilt, A potentiometer having a potentiometer that outputs a saturation signal when the amount of tilt of the lever and the electric signal according to the amount of tilt of the lever are operated to the limit, the resistance element of the potentiometer, and each of both ends of the resistance element in series. And a resistor that adjusts to output a saturation signal when the lever has the same resistance value and the amount of tilt of the lever is 95% or more of the maximum stroke.

[Action]

In the present invention configured as described above, by connecting a resistor in series with the resistance element of the potentiometer, the output voltage of the potentiometer can be adjusted by appropriately selecting the resistance value of the resistor, and the full stroke of the lever can be adjusted. , The saturation signal can be output only when tilted to 95% or more, and the output accuracy of the operation lever device can be easily improved. Moreover, it is not necessary to select and combine components, and the operation lever device can be obtained at low cost.

In the case where the potentiometer is of a rotary type, if resistors are connected to both ends of the resistance element and the resistance values of the respective resistors are the same, symmetry in the positive and negative directions with respect to the neutral position of the lever can be ensured. The same applies to the direct acting type. If the resistor is a variable resistor, the output voltage of the potentiometer can be easily adjusted, and the assembly of the device becomes extremely easy.

〔Example〕

Preferred embodiments of the operating lever device according to the present invention will be described in detail with reference to the accompanying drawings.

2 and 3 show an operating lever device according to an embodiment of the present invention.

In these figures, the operating lever device 10 is
The universal joint 14 is located in the center of the inside of the. The universal joint 14 has one shaft 16 fixed to the body 12 and a rotatable shaft 18
20, the lever 20 can be tilted by a predetermined angle in the left-right direction (X direction) of FIG. 1 and the direction (Y direction) perpendicular to the paper surface as described later. I have.

Further, around the universal joint 14, the pistons 22a to 22a in the X direction and the Y direction are spaced at 90 degrees from the center.
2d is located. These pistons 22a to 22d
It is movable vertically in the figure, and is urged upward by a spring 24 via a push-up plate 23. And
Pistons 22a to 22d are discs with the upper end attached to shaft 18.
The lever 20 is held at a neutral position (a position indicated by a two-dot chain line in FIG. 1) when the lever 20 is in contact with the lower end surface and no operating force is applied to the lever 20.

A rectangular bracket 28 having a circular hole at the center is fixed in the body 12. This bracket 28
Each side is arranged in the X direction and the Y direction, and a cut-and-raised portion 30 is formed at the center of each side.
A tilt angle detection sensor 32a composed of a rotary potentiometer that outputs an electric signal corresponding to the tilt angle θ of the lever 20 is provided at 30.
~ 32d is attached. And each tilt angle detection sensor 3
The ends of a pair of gimbals 36 and 38 arranged perpendicular to each other are connected to the rotatable detection shaft 34 of 2a to 32d. Slots 36a, 38a are formed in these gimbals 36, 38,
18, that is, the lever 20 can be tilted in the X direction and the Y direction.

The tilt angle detection sensors 32a to 32d have the same structure (represented by the reference numeral 32), and as shown in an equivalent circuit of FIG. Are fixed to the detection shaft. Accordingly, the wiper 40 rotates integrally with the detection shaft 34 and slides on the resistance element R. A resistor (fixed resistor) r having the same resistance value is connected in series to both ends of the resistance element R.

The operation of the embodiment configured as described above is as follows.

For example, the lever 20 is moved X along the long hole 38a of the gimbal 38.
When tilted in the direction, the side of the lever 20
Is pressed to rotate the gimbal 36. Since both ends of the gimbal 36 are connected to the detection axes 34 of the tilt angle detection sensors 32b and 32d, the detection axes 34 of these sensors are connected to the gimbal 36.
And the wiper 40 slides along the resistance element R. As a result, the tilt angle detection sensors 32b and 32d output an output voltage V ′ _OUT corresponding to the amount of tilt (operation amount) of the lever 20 in the X direction from the terminal connected to the wiper 40, and control of the work machine Used as a signal.

Meanwhile, the output voltage V of the inclination angle detecting sensor 32 'the maximum value of _OUT (e.g., output voltage when tilted full stroke lever 20 in the + X direction) with V' _MAX, the minimum value (lever 20
The 'When _MIN, the output voltage difference ΔV between the stroke end of the lever 20' the output voltage) when tilted full stroke in the -X direction V becomes as the following equation.

ΔV ′ = V ′ _MAX −V ′ _MIN = (V ₀ −rI ′) − {V ₀ − (r + R) I ′} = RI ′ (4) where I ′ is the current flowing through each resistor. It is. As is apparent from FIG. 1, I ′ = V ₀ / (2r + R) (5). By substituting equation (5) into equation (4), ΔV ′ = RV ₀ / (2r + R) ) (6)

On the other hand, in the case of a conventional sensor having no resistor r at both ends of the resistance element R, the applied voltage is V ₀ , and the current flowing through the resistance element R is I
Then, since the difference ΔV between the maximum output voltage V _MAX and the minimum output voltage V _MIN is equal to the voltage difference between both ends of the resistance element R, ΔV = RI = V ₀ (7) Therefore, (ΔV / ΔV ') = (2r + R) / R (8) ∴ΔV ′ = ΔV / ｛(2r + R) / R｝ = ΔV / ｛(1+ (2r / R)｝ (9)

In the above equation (9), in the tilt angle detection sensor 32 of the embodiment, the difference ΔV in the output voltage between the stroke ends of the lever 20 is obtained by changing the resistance value of the resistor r connected to both ends of the resistance element R. 'Can be changed. Therefore, if the difference ΔV in the output voltage between the stroke ends of the lever 20 and the total resistance value of the resistance element R are measured in a state where the resistor r of the tilt angle detection sensor 32 is not connected, the resistance of the resistor r is determined. By selecting the value, the output voltage difference ΔV ′ between the stroke ends can be made constant, and adjustment can be made so that the saturation signal is output at 95% or more of the full stroke of the lever 20.

As described above, in the embodiment, by connecting the resistor r having an appropriate resistance value to both ends of the resistance element R of the rotary potentiometer, the saturation signal is output only when the full stroke of the lever 20 is 95% or more. Can be output, and the accuracy of the device can be improved. In addition, since there is no need to select and combine parts, the process is simplified and the cost can be reduced. The resistance element R
By connecting a resistor r having the same resistance value to both ends of
The symmetry with respect to the neutral position of the lever 20 can be ensured.

In the above embodiment, the case where the fixed resistor r is connected to both ends of the resistance element R has been described. However, if a variable resistor is used instead of the fixed resistor r, the output voltage can be adjusted more easily. be able to.

In the above embodiment, the tilt angle detection sensor 32a
The case where a rotary potentiometer is used as ~ 32d has been described.
In the case of a direct-acting potentiometer that operates by the vertical movement of 22a to 22d, a fixed or variable resistor is connected to one or both ends of the resistive element R of the direct-acting potentiometer, and the output voltage is adjusted similarly. be able to. Further, in the above-described embodiment, the case where the tilt can be performed in the X direction and the Y direction has been described. However, the present invention can be applied to a lever that can be tilted in only one direction or a lever that can be tilted in more directions. .

[Effect of the invention]

As described above, according to the present invention, by connecting a resistor in series with the resistance element of the potentiometer, the resistance value of the resistor is appropriately selected, the output voltage of the potentiometer is adjusted, and the lever full The saturation signal can be output only when the stroke is 95% or more, and the output accuracy of the operation lever device can be easily improved.
Further, since it is not necessary to select and combine parts, the operation lever device can be obtained at low cost.

If the potentiometer is of the rotary type or direct acting type, connect resistors to both ends of the resistance element, and if the resistance value of each resistor is the same, ensure symmetry in the positive and negative directions with respect to the neutral position of the lever. Can be. If the resistor is a variable resistor, the output voltage of the potentiometer can be easily adjusted, and the assembly of the device becomes extremely easy.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram of a tilt angle detection sensor of the operating lever device according to the embodiment of the present invention, FIG. 2 is a sectional view of the operating lever device according to the embodiment, FIG. 3 is a plan view of the embodiment, FIG. FIG. 4 is an explanatory diagram of a rotary potentiometer of a conventional operating lever device, and FIG. 5 is a diagram illustrating a relationship between a lever operation amount of the conventional operating lever device and an output voltage of the potentiometer. 10 operating lever device, 14 universal joint, 20 lever, 32, 32a to 32d tilt angle detection sensor, 36, 38 gimbal, 40 wiper, R resistance element, r …Resistor.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-139734 (JP, A) JP-A-62-140636 (JP, U) JP-A-64-44476 (JP, U) JP-A-61-44476 59306 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A front-rear direction of a neutral position and / or
A lever that tilts in the left-right direction and the maximum stroke of the tilt is regulated, and a potentiometer that outputs an electric signal according to the tilt amount of the lever and a saturation signal when the tilt amount of the lever is operated to the limit. In the operating lever device having a resistance element of the potentiometer, and connected in series to both ends of the resistance element,
An operating lever device comprising: resistors each having the same resistance value and adjusting to output a saturation signal when the amount of tilt of the lever is 95% or more of the maximum stroke.