JPH0228028A - Transmission operation device of tractor and the like - Google Patents

Abstract

PURPOSE:To make it possible to stop a vehicle smoothly and to stop rapidly only by operating a brake pedal, by making the transmission control shaft of a hydraulic continuously variable transmission device varied and linked with the operation of a running pedal, and making it possible to operate to restore forcibly to the neutral position with the operation of the brake pedal. CONSTITUTION:In a hydraulic continuously variable transmission device in which the output rotation frequency is changed responding to the rotating operation of a transmission control shaft 2, a neutral restoration device which consists of a V-shape cam edge 8 at the upper end edge of a control arm 7, a neutral restoration arm 10 with a roll 9 to be pressed to the cam edge 8, a spring 11, and the like is provided to the control arm 7 of the transmission control shaft 2. And a running pedal 3 is pivoted 13 to a floor 12 of a driver seat, and the pedal 3 and the control arm 7 are linked with a rod 14. Moreover, a brake pedal 4 is provided at the pivoting member 13, and by depressing the pedal 4, a brake arm 17 is rotated through a rod 15, a spring 16, and the like, and a neutral restoration plate 18 is also rotated to restore the control arm 7 to the neutral position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a speed change operating device for tractors and the like, and can be used for other mobile agricultural machinery.

Prior Art and Problems to be Solved by the Invention In a driving operation mode in which a hydraulic continuously variable transmission is operated to continuously variable speed to transmit driving, the speed change control shaft of the transmission is moved from a neutral position to a forward position or to a reverse position. The hydraulic continuously variable transmission does not immediately return to the neutral position, but instead decelerates after a delay. It is difficult to stop suddenly because the vehicle returns to the neutral position while being stopped.

Means for Solving the Problems This invention provides a shift control shaft (2) of a hydraulic continuously variable transmission (1).
) is linked to gear change by operating the travel pedal (3), and
The gear shift operating device for a tractor or the like is configured such that it can be forcibly returned to the neutral position by operating the brake pedal (4).

Functions and Effects of the Invention When the foot is released from the travel pedal (3), the speed change control shaft (2) is in the neutral position and no travel transmission is performed.

When the travel pedal (3) is depressed in the forward direction, the shift control shaft (2) is rotated in accordance with the amount of depression, and continuously variable transmission is performed. If you press brake pedal 4) to make a sudden stop during such driving operations, this will cause the shift control shaft (2) to
is forcibly returned from the gear shift position to the neutral position. For this reason, when the brake pedal (4) is used to brake the vehicle, the hydraulic continuously variable transmission (1) is suddenly decelerated to a neutral position and no transmission is performed.

In this way, by depressing the brake pedal (4).

In order to forcibly return the shift position of the hydraulic continuously variable transmission +11 to the neutral position during gear transmission, the transmission is immediately set to neutral together with the brake, so that sudden stops can be made smoothly without exerting force on the transmission, and the brake level (4) is It can be done easily and quickly with just one operation.

Embodiment In addition, in rotation, the hydraulic continuously variable transmission has a variable displacement pump and a fixed displacement motor, and a variable displacement control shaft (2
) is used to transmit the speed change of the fixed displacement motor and output shaft, and the neutral position (N
), no gear transmission is performed, and the forward position is higher than this!
When performing the rotation operation in (F), the speed is increased sequentially to a forward high speed,
Moreover, by returning to the neutral position (N), the speed is decelerated and it comes to a stop. Also, neutral position! When the vehicle is rotated from (N) to the reverse position (R), reverse power transmission travel is carried out in the same manner. The output shaft of this hydraulic continuously variable transmission (1) is connected to the auxiliary transmission, steering clutch, and steering brake (6) in the transmission case (5).
The transmission is configured to be transmitted to the left and right wheel axles via the brake pedal (4), and the left and right steering brakes (6) are activated by depressing the brake pedal (4).
It is configured to brake the In addition, this brake (6)
Alternatively, the rotation of both the left and right axles may be braked simultaneously.

The control arm (7) of the speed change control shaft (2) has a neutral return arm (1) having a V-shaped cam edge (8) on its upper edge and a roll (9) that presses against this cam edge (8). , the spring that springs this neutral return arm fiG (by +11, etc.,
A neutral return device is provided. The floor in front of the cockpit (on the floor, the driving pedal (3) is pivoted so that it can be rotated in the front and back direction
The travel pedal (3) and the control arm (7) are connected by a rod (141).By depressing the travel pedal (3) to the front, the gear is shifted to the forward position @ (F), By depressing the pedal to the rear, the gear changes to the reverse position [(R). Also, when the driving pedal (3) is released, it returns to the neutral position.

In addition, a brake pedal (4) is provided on the pivot portion (131), and by stepping on this brake pedal (4), the brake arm (1 arm) of the brake (6) is rotated via a rod (19° spring, etc.). The rod (19) of this brake pedal (4) can brake the wheel axle of the traveling device.
is linked to the neutral return plate C11, and the brake pedal [
4), the neutral return plate (old) is rotated to move the control arm (7) to any shift position (F) (R).
The structure is such that it can return from the position to the neutral position (N). This neutral return plate (18 is pivoted to the frame 0 like the pivot part (13) of the brake pedal (4) G!l L,
, insert the rod fls into this plate (engagement hole 1 of lυ)
A guide groove around the pivot portion (2II+) is formed at the tip of the six-pronged neutral return plate (11) that engages the engagement pin Q3 of I.

At the opening of this guide groove, a reverse return side return edge circle is formed on the side of the pivot part ffl, and a forward side return afsi is formed on the opposite side.
The rotation of the neutral return plate +I1m engages the return pin r2 of the control arm (7) and guides it to the guide groove, thereby shifting the shift control arm (7) at any shift position to neutral. Rotate to position ffi (N). At this time, the rod (19) is in a position to apply the brake (6).

(5) is a parking lever provided on the brake pedal (4), and by engaging the rack part with the locking part +21 below the floor +17J, the parking brake fixes the brake pedal (4) at the brake position. I can do it.

The mark is the input shaft of the hydraulic continuously variable transmission (1), and the OI is the fan installed on this input shaft (21).
1), the transmission case (5), etc.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show one embodiment of the present invention, and FIG. 1 is a partial side view, FIG. 2 is a plan view, and FIG. 3 is a partial enlarged side view. . In the figure, (1) is a hydraulic continuously variable transmission, (2) is a shift control shaft, (3) is a travel pedal, (4) is a brake pedal,
(5) is a transmission case, (6) is a brake, (7) is a control arm, and fll is a neutral return plate.

Claims (1)

[Claims] The gear change control shaft (2) of the hydraulic continuously variable transmission (1) is provided so as to be operable to change gears by operating a travel pedal (3) and forcibly return it to a neutral position by operating a brake pedal (4). A speed change operation device for tractors, etc.