JPH0647206Y2 - Drive control switching device for power take-off shaft in ground work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a drive control switching device for a power take-off shaft in a ground work vehicle such as an agricultural tractor.

[Problems to be Solved by Prior Art and Invention] Generally, in this type of ground work vehicle, a power take-off shaft (PTO
There is one that can be switched between a constant drive control in which the shaft is always rotated and a standard drive control in which the rotation is stopped in accordance with the cutting operation of the aircraft traveling clutch. In such a configuration, the control switching is performed by operating the control switching switch. However, when the engine is started and the drive control state is set, the power take-off shaft may unexpectedly rotate. Therefore, there is an attempt to prevent the engine from starting unless the control switching switch is constantly switched to the stopped state.

However, in such a case, the starter motor may not operate even if the starter switch is operated to start the engine, and as a cause, it is necessary to confirm whether or not the control switching switch remains in the drive control state. In that case, it is necessary to stare at the switching levers and knobs of the control changeover switch, and it is not possible to fully confirm them with an instant visual inspection.For example, operating the control changeover switch. If it is arranged at the back of the seat and the switch switching operation is performed while checking the rear, it is troublesome because it is necessary to look back and check the switch status. To be done.

[Means for Solving the Problem] In view of the above situation, the present invention was devised with the object of providing a drive control switching device for a power take-off shaft in a ground work vehicle capable of eliminating these drawbacks. The power take-off shaft that outputs power to the work unit attached to the traveling machine always rotates regardless of the intermittent operation of the aircraft traveling clutch, and rotates with the disconnecting operation of the aircraft traveling clutch. In a ground work vehicle including a control switch that can switch between standard drive control that stops the engine and a constant stop control that always stops, and a starter switch that can start the engine, a control switch that is optional while the engine is operating. The control panel is equipped with a monitor lamp that lights up when switching to the drive control position of the starter switch. The relay coil of the safety relay switch, to which the relay switch contact is connected in the circuit from the switch terminal, and the monitor lamp, do not apply current to the relay coil and the monitor lamp when the control switching switch is constantly stopped. It is characterized in that it is connected in series to the circuit from the access terminal of the starter switch.

The present invention, with this configuration, can remarkably improve the safety at the time of switching the control of the power take-off shaft.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a traveling machine body of an agricultural tractor, and a working section (rotary tilling section) 3 is attached to a rear portion of the traveling machine body 1 via an elevating link mechanism 2. The working unit 3 is moved up and down by vertically swinging the lift arm 5 extending from the hydraulic case 4. Also,
A power take-off shaft (PTO shaft) 6 connected to the working unit 3 projects rearward from below the hydraulic case 4, and the power take-off shaft 6 is rotated by driving the engine so that the working unit 3 is While working, both of these configurations are conventional.

Reference numeral 7 is a hydraulic clutch interposed in a power transmission circuit from the engine 8 to the power take-off shaft 6, and the hydraulic clutch 7
Is controlled to be turned on and off by turning on and off an electromagnetic valve 9 described later. Further, 10 is a switching switch for switching the drive control of the power take-off shaft 6, which is arranged on the right rear part of the switching switch 10, the driver's seat 11, that is, the center cover 12 covering the hydraulic case 4, and By the switching operation of the switching switch 10, as will be described later, the continuous drive (independent) control (IND-PTO) for constantly rotating the power take-off shaft 6 and the disconnection operation of the main clutch pedal 13 for traveling the aircraft are performed. Along with this, the standard drive control (STD-PTO) that stops rotation and the constant stop control (OFF) that is always stopped can be switched.

On the other hand, 14 is a monitor lamp arranged on the front operation panel 15 in front of the driver's seat 11, and the monitor lamp 14 is
When the switching switch 10 is set to the position of the constant drive control or the standard drive control, the switch 10 is turned on to inform the drive operator of the output take-out shaft 6. In addition, the starter switch (ignition switch) 16
Is keyed to the access terminal AC position during normal operation, and when the engine is started, the key is operated through the access terminal AC position to the start terminal ST position.
The monitor lamp 14 is thin even when the switching switch 10 is set to the OFF position in the state where the starter switch 16 is operated to the access terminal AC position before the key operation to the start terminal ST position to start the engine 8. It comes to light up.

That is, in order to prevent the power take-off shaft 6 from being suddenly driven at the same time when the engine 8 is started, at the time of starting the engine 8, a safety relay switch that energizes only when the switching switch 10 is set to the OFF position. 17 is provided, and the switch contact 17b of the safety relay switch 17 is connected to the circuit from the start terminal ST of the starter switch 16, and this switch contact 17b is closed by the excitation of the relay coil 17a and the main clutch pedal. The safety lamp 20 is configured to be able to drive and operate the starter 18 only when the safety switch 20 is closed and energized by depressing 13.However, the monitor lamp 14 works together with the relay coil 17a of the safety relay switch 17 together. , The switching switch 10 is turned off by connecting in series with the circuit from the access terminal AC of the starter switch 16. Comes to the current applied to the relay coil 17a becomes resistive, correspondingly, the applied voltage is summer to light thin reduced.

Next, a drive control system of the power take-off shaft 6 by the control unit 19 provided on the side of the driver's seat 11 will be described with reference to the flowchart shown in FIG. The control unit 19 is composed of a microcomputer and the like, and
The switching switch 10, a safety switch 20 for detecting a disconnection operation of the main clutch pedal 13, and a lever position detection switch 22 for detecting an ascending operation of the elevating lever 21 of the working unit 3.
A drive signal of the power take-off shaft 6 is controlled by inputting a detection signal from the above, and based on the determination, the electromagnetic valve 9 is turned on and off to intermittently control the hydraulic clutch 7. That is,
When the control is started, "0" is first set in the register A, and subsequently, it is judged which drive control position the switching switch 10 is set to. When the drive control shaft is set to the constant drive control position, the power take-off shaft 6 is
The electromagnetic valve 9 is continuously turned on by controlling by the first mode in which the motor is driven to the rated rotation in T ₁ time (for example, 1 second in the embodiment), and once driven, the register A is set to “1”. In operation, the power take-off shaft 6 is always driven and controlled.

On the other hand, when the switching switch 10 is set to the standard drive control, it is first determined whether the safety switch 20 is ON, and if this is YES, the electromagnetic valve 9 is turned off.
FF will be activated, and safety switch 20 will be OF
In the case of F, the register A is controlled to drive the power takeoff shaft 6 after determining whether the electromagnetic valve 9 is OFF. That is, when "1" is set in REJIGSTA A, the electromagnetic valve 9 is continuously operated.
When the register A is judged to be "0", it is further judged whether or not the lever position detection switch 22 is turned on. If it is YES, the power take-off shaft 6 is set in the first mode. When the drive control is performed, on the other hand, when it is determined to be ON, the power take-off shaft 6 is operated for T ₂ hours (for example, in the embodiment,
The drive is controlled by the second mode in which the motor rotates at the rated speed in 0.5 seconds).

The drive control in the first mode and the second mode is performed by operating the electromagnetic valve 9 by a predetermined inching operation.

In the embodiment of the present invention configured as described above, the drive control of the power take-off shaft 6 is switched by turning the switch 10 arranged on the center cover 12 while the operator is seated on the driver's seat 11. It will be done by switching operation.

That is, at the time of switching the control, the operator performs an operation while looking at the rear side where the working unit 3 is attached, and at this time, the safety confirmation of the rear side is always performed. Therefore, it is possible to surely avoid the risk of switching the switch 10 to the drive control side and activating the working unit 3 without noticing the presence of a person or an object near the working unit 3, and as a result, the safety can be improved. Will be significantly improved. Moreover, when the switching switch 10 is operated, it is possible to confirm the operation of the working unit 3 as well as the rearward confirmation, so that a reliable operation is possible, which is more convenient.

Further, since the front operation panel 15 is provided with the monitor lamp 14 which is turned on during the drive control of the power take-off shaft 6, the power take-off shaft 6 can be driven without directly looking at the switching switch 10 even during the normal work performed facing forward. That is, the operation of the working unit 3 can be confirmed by the monitor number 14, and the safety and operability can be further improved.

Moreover, when the engine is started, the switching switch 10
The safety relay switch 17 is provided so that the engine will not start unless it is in the constant stop control state.The relay coil 17a of this safety relay switch 17 is connected to the starter lamp 14 along with the monitor lamp 14. As a result of being connected in series to the circuit from the access terminal AC of the switch 16, the current applied to the monitor lamp 14 when the control switching switch is in the constant stop control state is
Compared with the case where the switching switch 10 is set to an arbitrary drive control position, the monitor lamp 14 can reduce the consumption by the relay coil 17a.
Can be distinguished from the fact that it lights up lighter than when it is set to an arbitrary drive control position, which allows the switching switch 10 to be set in a state where the engine can be started, that is, whether it is set to the constant stop control state. The operator can instantly recognize whether or not, and the cause of the case where the engine does not start when the engine is started is that the control switching switch 10 is not switched to the constant stop control state. Whether or not it can be confirmed quickly. As a result, there is no problem in arranging the control switching switch 10 in the rear of the driver's seat, where the safety confirmation at the rear is always required by looking back to the second half of the body during the switching operation. Therefore, it is possible to make a distinction. Therefore, it is possible to surely avoid the risk of erroneously recognizing the working state of the working unit 3 when the electric light is turned off.

Moreover, in this device, when the drive shaft of the power take-out shaft 6 is standardly driven and controlled, the drive of the power take-out shaft 6 is stopped by the operation of the main clutch pedal 13, and then the drive shaft of the power take-out shaft 6 is driven again. Is shorter than the time (1 second in the 1st mode) required to reach the rated speed (2nd
In this mode, the drive is controlled so that the rated speed is reached in 0.5 seconds), so, for example, when working with a rotary tiller, after turning off the main clutch pedal 13 due to the load and the engine speed dropping, When performing work, the power take-off shaft 6 will return to the rated rotation in a shorter time than the conventional one, so that uncultivated land will be generated until the power take-off shaft 6 reaches the rated rotation as in the conventional case. I won't let you. Moreover, when the working unit 3 is in the raised position, normal control is performed, so that safety is ensured as in the conventional case.

Of course, the present invention is not limited to the above-mentioned embodiment, but may be constituted by a circuit as shown in FIG. 8 without using, for example, a microcomputer. In this case, 23 is installed in parallel with the safety switch 20 and is turned off when the main clutch pedal 13 is turned off.
It is a pedal switch that does.

[Effects] In summary, since the present invention is configured as described above, the monitor lamp lights up when the control switching switch for switching the drive control of the power take-off shaft is operated to any drive control position. The operator will be informed that the power take-off shaft is in the drive control state, but this monitor lamp is designed with safety in mind so that the engine cannot be started unless the control changeover switch is constantly stopped. As a result of being connected in series with the circuit from the access terminal of the starter switch together with the relay coil of the safety relay switch, the current applied to the monitor lamp when the control switch is always stopped is controlled by the control switch. Is consumed in the relay coil connected in series as compared with the case where it is set to the drive control position of As a result, the monitor lamp lights up more lightly than when the control switching switch is set to an arbitrary drive control position, so that the two can be distinguished.
This means that when the starter switch is keyed to the access terminal position when starting the engine, the control switching switch is set to a state in which the engine can be started, that is, a constant stop control state. Can be instantly recognized, and it is possible to quickly confirm that there is no cause here when the starter switch does not start even when the engine is started. As a result, there is no problem in arranging the control switching switch in the rear of the driver's seat where the safety confirmation at the rear is always required by looking back to the second half of the body during the switching operation. It has the advantage that it can be done.

[Brief description of drawings]

1 is a side view of an agricultural tractor, FIG. 2 is a plan view of the same, and FIG. 3 is a plan view of the same. Is a front view showing the mounting state of the switching switch,
FIG. 6 is a front view of the operation panel, FIG. 5 is a hydraulic circuit diagram of the power take-out shaft drive control mechanism, FIG. 6 is an electric circuit diagram of the same, FIG. 7 is a flowchart of the same, and FIG. 8 is a circuit showing a second embodiment. It is a figure. In the figure, 1 is a traveling machine body, 3 is a working unit, 6 is a power take-off shaft,
10 is a switching switch, 11 is a driver's seat, 12 is a center cover, 13 is a main clutch pedal, 14 is a monitor lamp, and 15 is an operation panel.

Claims (1)

[Scope of utility model registration request] 1. A continuous drive control in which a power take-out shaft for outputting power to a working unit attached to a traveling machine always rotates regardless of an intermittent operation of a vehicle traveling clutch, and a rotation accompanying the operation of disconnecting the vehicle traveling clutch. In a ground work vehicle provided with a control switching switch capable of switching between standard drive control for stopping and constant stop control for constantly stopping, and a starter switch capable of starting an engine, in a ground work vehicle, any one of the control switching switches can be operated while the engine is operating. A monitor lamp that lights up when switching to the drive control position is provided on the control panel, and the relay coil and the monitor lamp of the safety relay switch in which the relay switch contact is connected in the circuit from the start terminal of the starter switch. When the control switching switch is switched to the constant stop control position, the relay coil and Current applied to the fine monitor light driving control switching device for a power takeoff shaft in ground work vehicle, characterized in that connected in series to a circuit from the access terminal of the starter Sui Tutsi to be made.