JP2555654B2 - Vehicle speed control device for mobile agricultural machinery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle speed control device for a mobile agricultural machine such as a combine or a tractor.

2. Description of the Related Art Conventionally, a potentiometer for detecting the forward / backward shift operation position of a shift lever is provided, and a potentiometer for detecting the rotational position of a swash plate shaft for controlling the drive of a hydraulic continuously variable transmission and the swash plate shaft are rotated. There is a technique in which a hydraulic cylinder is provided, and the swash plate shaft is rotated by the hydraulic cylinder according to the gear shift operation position of the gear shift lever to shift gears.

Problems to be Solved by the Invention In the prior art, since the hydraulic cylinder is always operated at the same speed to rotate the swash plate shaft in accordance with the forward and backward shifting operation of the shift lever, the traveling device is In the case where the auxiliary transmission that transmits power is provided, if the operating speed of the hydraulic cylinder is set so that the auxiliary transmission can be smoothly started at the low speed position, the aircraft will suddenly move from the stopped state at the time of start at the high speed position. There was a problem that the maneuverability was poor.

In view of this, the present invention is intended to ensure good maneuverability by smoothly starting the vehicle according to the high speed and low speed positions of the auxiliary transmission.

Means for Solving the Problems The present invention provides a gear shift by rotationally controlling a swash plate shaft (3) that controls the drive of a hydraulic continuously variable transmission (2) according to a gear shift operation position of a gear shift lever (1). In traveling mobile agricultural machines,
A vehicle speed control device for a mobile agricultural machine or the like is provided with a speed change control device for controlling the rotation of the swash plate shaft (3) to a slow speed or a high speed according to the high speed or low speed position of the auxiliary transmission device (4).

Action and effect of the invention Shift lever (1) with auxiliary transmission (4) at high speed position
When the gear shift operation is performed, the gear shift control device is actuated to control the rotation of the swash plate shaft (3) to be slow, the drive of the hydraulic continuously variable transmission (2) is controlled, and the vehicle gradually starts. When the speed change lever (1) is operated to shift with the auxiliary transmission (4) at the low speed position, the swash plate shaft (3) is controlled to rotate faster, and the drive of the hydraulic continuously variable transmission (2) is controlled. , Start at an appropriate speed.

In this way, the rotation of the swash plate shaft (3) is controlled to be slow and fast by the shift control device in accordance with the high speed and low speed positions of the auxiliary transmission device (4). The vehicle can be started and run at an appropriate speed, and can be started at an appropriate speed at a low speed position, so that riding comfort and maneuverability can be improved.

Embodiment In addition, in the illustrated example, (1) is a gear shift lever provided in the cockpit, and a potentiometer (6) for detecting the forward / backward shift operation position of this gear shift lever (1) is provided.
(3) is a swash plate shaft that controls the drive of the hydraulic continuously variable transmission (2). By rotating the swash plate shaft (3) from the neutral position in the front-rear direction, the traveling vehicle body is continuously moved forward and backward. With this configuration, an auxiliary transmission device (4) for changing the traveling speed between high speed and low speed is provided.

The swash plate shaft (3) is provided with a potentiometer (7) for detecting the rotation angle of the swash plate shaft (3), and one end of a control arm (8) is fitted into the swash plate shaft (3). A hydraulic cylinder (9) for rotating the swash plate shaft (3) is connected to the end. The hydraulic cylinder (9) is expanded and contracted by hydraulic pressure and has an electromagnetic valve (10).

FIG. 2 is a block circuit diagram in which a controller (11) having a CPU and a memory has a potentiometer (6) for detecting a shift position of the shift lever (1) through an A / D conversion circuit (14). Detection information, as well as the A / D conversion circuit (1
5) detection information of the potentiometer (7) for detecting the rotation angle of the swash plate shaft (3), and setting information of the high speed and low speed positions of the auxiliary transmission (4) via the digital input circuit (17). The drive pulse signal from the controller (11) is given to the solenoid (12) for advancing the electromagnetic valve (10) via the output circuit (16) and the solenoid (13) for advancing through the output circuit (18). It is configured to be given to each.

When the setting information of the high speed or low speed position of the sub transmission (4) is given to the controller (11) via the digital input circuit (17), the controller (1
A shift control device is provided so that the on-time duration of the control pulse signal output from the solenoid valve (10) to the forward solenoid (12) or the reverse solenoid (13) of the electromagnetic valve (10) is adjusted.

FIG. 3 shows the control pulse signal. When the auxiliary transmission (4) is at the high speed position, the drive pulse signal (a) with a short on-time within one cycle (T) is the swash plate. It is transmitted to the electromagnetic valve (10) until the shaft (3) reaches a predetermined rotation angle, and gradually the hydraulic cylinder (9) so as not to start suddenly.
When the auxiliary transmission (4) is in the low speed position, the drive pulse signal (b) which sets the on-time within one cycle (T) longer than that in the high speed position is applied to the electromagnetic valve (10). ), The hydraulic cylinder (9) so that the start control does not take too long and the start control does not take too long.
It is configured to control so as to operate.

When the sub transmission (4) is set to the high speed position, this setting information is given to the controller (11). Shift lever (1)
When the forward operation is performed, this operation position is detected by the potentiometer (6) and input to the controller (11). From the controller (11) to the forward solenoid (12), a drive pulse signal (a) with a short on-time is sent. Is transmitted, the hydraulic cylinder (9) is gradually operated, the swash plate shaft (3) is rotated toward the forward side, and the continuously variable transmission (2) is driven. The rotation angle of the swash plate shaft (3) is detected by the potentiometer (7), and the drive pulse signal (a) is transmitted until the rotation angle reaches a predetermined angle, so that the aircraft smoothly moves at a stable speed. Take off. Even in the case of traveling in reverse, it is possible to smoothly start.

When the auxiliary transmission (4) is set to the low speed position, the drive pulse signal (b) whose on-time is longer than that of the drive pulse signal (b) prevents the vehicle from starting suddenly and the start control does not take too long. You can start.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an operation explanatory view, FIG. 2 is a block circuit diagram, and FIG. 3 is a drive pulse signal waveform diagram. In the figure, reference numeral (1) is a gear shift lever, (2) is a hydraulic continuously variable transmission, (3) is a swash plate shaft, (4) is an auxiliary transmission, and (11) is a controller.

Claims (1)

(57) [Claims] 1. A swash plate shaft (3) for controlling the drive of a hydraulic continuously variable transmission (2) according to a gear shift operation position of a gear shift lever (1).
In a mobile agricultural machine in which the rotation of the swash plate shaft (3) is controlled to rotate in a variable speed, a shift control device for controlling the rotation of the swash plate shaft (3) to be slow or fast in accordance with the high speed or low speed position of the sub transmission (4) is provided Vehicle speed control device for mobile agricultural machines.