JPH03213757A - Position detection structure of speed setting control lever - Google Patents

Abstract

PURPOSE:To prevent the occurrence of unevenness of a travel speed at the highest speed position of an operation lever, by making a constitution in which the operation lever and a potentiometer are made to be of a contact-butt structure using a spring, and making a structure in which the detection arm of the potentiometer is directly stopped by means of a stopper. CONSTITUTION:When an operation lever 11 is kept on being operated to a low speed side, the operation lever 11 keeps on pushing the detection arm 14 of a potentiometer 13 to a low speed side. Conversely, when the operation lever 11 is operated to a high speed side, the detection arm 14 keeps on moving to the high speed side by following the operation lever 11 by means of the energizing force of a spring 17 provided at the detection arm 14. As above, the position of the operation lever 11 is detected by means of the detection arm 14 of the potentiometer 13. And when the operation lever 11 is operated up to the predetermined highest position, the detection arm 14 of the potentiometer 13 is to be stopped at a position opposing the predetermined highest position of a stopper 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for detecting the operating position of an operating lever for changing the travel speed of a working vehicle or the speed changing of a working device.

[Conventional technology]

Some riding rice transplanters, which are one type of work vehicle, are equipped with a continuously variable transmission device that combines a split pulley and a transmission belt for running. Then, the operation position of the shift control lever is detected by a rotary potentiometer, and the speed is adjusted to correspond to this operation position.
The continuously variable transmission is controlled by an actuator.

[Problem to be solved by the invention]

When detecting the operating position of the operating lever using a rotary potentiometer as described above, if the operating lever is directly connected to the detection shaft of the potentiometer, the potentiometer may be damaged if a large external force is applied. It has been proposed to separate the positions of the potentiometer and the potentiometer, and to link the operating lever and the detection shaft of the potentiometer in an interlocking manner via a link mechanism.

However, if a mechanical link mechanism is provided between the operating lever and the detection shaft of the potentiometer, the link mechanism may have looseness or mechanical errors. Variations occur in the positional relationship with the shaft. In particular, when the operating lever is operated to the highest speed position, 1. Due to the above-mentioned variations, the maximum vehicle speed varies greatly.

Here, an object of the present invention is to configure the vehicle so that there is no variation in the traveling speed or the maximum speed of the working device when the operating lever is operated to the maximum speed position.

[Means to solve the problem]

The feature of the present invention is that the position detection structure of the speed setting operating lever is configured as follows. In other words, a spring is provided that urges the swinging detection arm of the rotary potentiometer toward the high speed side, and a stopper is fixed that contacts and stops the detection arm itself at a position corresponding to a predetermined maximum speed position. At the same time, the detection arm is brought into contact with an operating lever that is artificially operated to swing from the low speed side, and the detection arm is made to follow the swinging operation of the operating lever, so that the position of the operating lever is controlled by a potentiometer. The functions and effects are as follows.

[For production]

With the above configuration, when the operating lever is operated toward the low speed side, the operating lever pushes the detection arm of the potentiometer toward the low speed side. Conversely, when the control lever is operated to the high speed side, the detection arm follows the control lever and moves to the high speed side due to the biasing force of the spring provided on the detection arm. As described above, the position of the operating lever is detected by the detection arm of the potentiometer.

When the operating lever is operated to a predetermined maximum speed position, the detection arm of the potentiometer comes into contact with the stopper, and the detection arm is stopped at a position corresponding to the predetermined maximum speed position of the operating lever. As a result, even if the predetermined maximum speed position of the operating lever is located on the higher speed side than the position where the detection arm is stopped by the stopper, the detection arm moves away from the operating lever and is stopped at the predetermined position by the stopper. It will be done.

〔Effect of the invention〕

As described above, the operating lever and potentiometer are not directly connected, but instead have a contact structure using a spring, and the detection arm of the potentiometer is raised directly by the stopper. Even if the predetermined maximum speed position varies on the high speed side, a constant output value corresponding to the maximum speed can be obtained from the potentiometer, resulting in a stable speed setting structure with little variation.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Fig. 4, a seedling planting device (3) is connected to the rear of the machine supported by front wheels (1) and rear wheels (2) so that it can be raised and lowered. A model rice transplanter is configured. The transmission system of this riding rice transplanter is constructed as follows. In other words, as shown in Figure 3, the engine (
The power from 4) is transmitted to the front wheels (1), rear wheels (2), and seedling planting device (3) via a double split pulley type continuously variable transmission (5) and a gear transmission (6). ).

The continuously variable transmission (5) is operated to change speed by an electric cylinder (8) via a link rod (7).

Then, the electric cylinder (8) is operated by a control lever (11) provided on the instrument panel (lO) of the control section (9).

Next, a structure for detecting the operating position of the operating lever (11) will be explained. As shown in Figures 1 and 2, a rotary potentiometer (1) is attached to a fixed support plate (12).
3) is installed horizontally. A detection arm (14) is provided to be able to swing vertically around the axis (Pl) of the potentiometer (13).
3), the detection arm (14) is biased toward the high speed side (upward in the paper in FIG. 2) by a spring (not shown) installed inside the sensor. A roller (15) is attached to the tip of the detection arm (14), and a washer (16) is attached to the end of the roller (15). Furthermore, as shown in FIG. 2, a stopper (18) comes into contact with and stops the detection arm (14) at a position corresponding to a predetermined maximum speed position (MAX) of the operating lever (11), which will be described later.
is fixed to the support plate (12).

On the other hand, on the support plate (12), the operating lever (11) is swingably supported around a horizontal axis (P2) remote from the potentiometer (13). Then, a part of the support plate (12) is bent and a stopper (
12a) and the operating lever (11) to the lowest speed position (MIN
) is provided with a stopper (12b). Further, a disc spring (17) is attached to frictionally hold the operating lever (11) at any position between the maximum speed position (MAX) and the minimum speed position (MIN).

Then, as shown in Figures 1 and 2, the operation lever (
An arm (lla) extends from the base of 11),
The roller (15) of the detection arm (14) of the potentiometer (13) is in contact with the arm (lla) of the operating lever (11) from the low speed side (lower side of the page in FIG. 2).

With the above structure, the operating lever (11) can be moved to the low speed side ((M
(IN) side), the arm (lla) of the operating lever (11) pushes down the detection arm (14) of the potentiometer (13) to the low speed side. Conversely, when the operation lever (11) is operated to the high speed side ((MAX) side), the biasing force of the spring provided on the detection arm (14) causes the detection arm (14) or the arm of the operation lever (11) to move. (
lla) and move toward the high speed side. As described above, the position of the operating lever (11) is detected by the detection arm (14) of the potentiometer (13) and input to the control device (24).
The electric cylinder (8) is operated by the control device (24) so that the continuously variable transmission (5) is shifted to a speed corresponding to the position 1).

Then, as shown in Fig. 2, when the operating lever (11) is operated to the predetermined maximum speed position (MAX), the detection arm (14) of the potentiometer (13)
When the detection arm (14) comes into contact with the operating lever (1), the detection arm (14)
It is stopped at a position corresponding to the predetermined maximum speed position (MAX) of 1). And in this case the arm (lla
) and the roller (15) to create a slight gap.

In addition, as shown in Figures 3 and 5, there is a lift lever (2) on the side of the cockpit (20) for lifting and lowering the seedling planting device (3).
1) is provided. And this lift lever (21
), the auxiliary lever guide (22) crossing the lever guide (22) is placed in the neutral stop position (N) of the lever guide (22).
a) is provided. Then, when the elevator lever (21) is inserted into the auxiliary lever guide (22a) and held, the fourth
Seedling planting device (3) shown in the figure Hydraulic cylinder for lifting (23
) is closed, and the seedling planting device (3) is stopped at that position.

Although the above-mentioned embodiment shows an operation lever for changing the traveling speed of a riding-type rice transplanter, the present invention may be applied to changing the speed of a working device in other working vehicles.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the position detection structure of the speed setting operating lever according to the present invention, and FIG. 1 is a plan view of the operating lever and the vicinity of the potentiometer, and FIG. 2 is a view taken from the direction of the arrow in FIG. 1. Figure 3 is a side view showing the speed change operation system of the continuously variable transmission for traveling, Figure 4 is an overall side view of the riding rice transplanter, and Figure 5 is the lever guide of the lift lever for the seedling planting device. FIG. (11)......operation lever, (13)...
- Potentiometer, (14)...Potentiometer detection arm, (18)...Stopper (MAX)...Predetermined maximum speed position.

Claims (1)

[Claims] A spring is provided to bias the swinging detection arm (14) of the rotary potentiometer (13) toward the high speed side, and the detection arm (14) contacts itself at a position corresponding to a predetermined maximum speed position (MAX). A stopper (18) is fixed to stop the stopper (18), and the detection arm (14) is brought into contact with the operating lever (11), which is artificially operated by swinging, from the low speed side. A position detection structure for a speed setting operating lever, in which the position of the operating lever (11) is detected by a potentiometer (13) by causing the detection arm (14) to follow the swinging operation of the operating lever.