JPH06227412A - Steering driving device in working running vehicle - Google Patents

Abstract

PURPOSE:To automatically disconnect power transmission between a driving means and a steering shaft in the manual steering state in a working running vehicle which can be switched to manual steering using a driving means and to manual steering by steering wheel rotation. CONSTITUTION:A steering driving device in a working running vehicle is so constructed that an intermittent clutch mechanism 27 is provided in a power transmission path extending from an electric motor 16 to steering shafts 12, 13, and further the intermittent clutch mechanism 27 is provided with an automatic clutch switching means for automatically intermittently switching the clutch, interlocking with switching between manual steering and automatic steering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering drive device for a work vehicle such as a field work vehicle or a waste land work vehicle.

[0002]

BACKGROUND OF THE INVENTION Generally,
This type of work vehicle includes unmanned travel that is performed remotely by wireless guidance, detection of existing travel traces, detection of existing work traces, index recognition, etc., and manned travel in which the driver directly steers to travel. In such a case, driving means such as an electric motor or a hydraulic motor are interlockingly connected to the steering shaft in such a case, and when the vehicle is unmanned, an automatic steering state based on the driving of the driving means is performed. When the vehicle is traveling, the manual steering state is switched based on the steering wheel operation by the driver. However, in such a device, it is preferable to transmit the rotation of the driving means in a state of low rotation and high torque as much as possible in order to miniaturize the driving means. Therefore, the deceleration is performed between the driving means and the steering shaft. Means will be provided. At that time, even if the drive means is moved (slip) from the steering shaft side, the drive means is practically not moved due to the existence of the speed reduction means, and as a result, If this is left as it is, manual steering cannot be performed.

In order to avoid this, in the conventional device, a torque limiter, which is also used as a measure against overload, is interposed between the deceleration means and the steering shaft, and the trip from the steering shaft side is performed by the trip of the torque limiter. The force to move the means was cut off to allow manual steering. However, with this one, it is necessary to adjust the trip torque of the torque limiter to a setting that can withstand the drive load from the drive means side in the case of automatic steering, and it is difficult to adjust the torque of the torque limiter.
In the case of manual steering, the steering wheel must be operated with a force that exceeds the trip torque of the torque limiter, which causes a problem of heavy steering operation and poor workability.

Therefore, instead of the torque limiter, or an interrupting clutch means is provided between the torque limiter and the steering shaft so that the clutch operating tool such as a lever is in a continuous clutch state during automatic steering, and is in a disconnected state during manual steering. It is advocated to do. However, work vehicles that are frequently manned and unmanned (for example, road traveling is manned even under the Road Traffic Law, but work traveling in fields or wastelands is unmanned). In the case of a car), this switching operation is troublesome and complicated, and there is a problem that troubles often occur due to forgetting to switch.

[0005]

DISCLOSURE OF THE INVENTION The present invention was devised with the object of providing a steering drive device for a work vehicle capable of eliminating these drawbacks in view of the above circumstances. , A driving means is interlockingly connected to a steering shaft which is rotated by manual steering of a steering wheel via a speed reduction mechanism, and is switched between an automatic steering state based on driving of the driving means and a manual steering state based on rotation of the steering wheel. In the work vehicle configured as described above, in the power transmission path from the speed reduction mechanism to the steering shaft, when providing the interrupted clutch mechanism for interrupting the power transmission, the interrupted clutch mechanism has a manual steering state and Linked to the switching of the automatic steering state, the clutch is disconnected in the manual steering state, and the clutch continuation state in the automatic steering state. In which it characterized in that a clutch automatic switching means for switching to.

According to the present invention, in this configuration, the intermittent clutch mechanism for interrupting the power transmission between the automatic steering drive source and the steering shaft can be automatically switched in the manual steering state. This is an improvement in operability.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described with reference to the drawings. In the drawing, reference numeral 1 denotes a traveling machine body of a seedling transplanting work machine, and a seedling transplanting machine 2 is attached to a rear portion of the traveling machine body 1 so as to be vertically movable via an elevating link device 3. Further, 4 is a front wheel, 5 is a rear wheel, 6 is an engine, 7 is a transmission case, and 8 is a traveling speed change operation tool (lever).

Reference numeral 10 denotes a steering wheel arranged in front of the driver's seat 11.
0 is integrally provided on the lower end of the first steering shaft 12 and the upper end of the second steering shaft 13 is connected to the joint 1.
It is integrally connected via 4, but the joint 14
A casing 15 configured to largely cover the vehicle is integrally provided on the machine body side, and an electric motor 16 for forward / reverse driving is fixed to the upper surface of the casing 15.
The output shaft 16a of the electric motor 16 projects into the casing 15, but the output shaft 16a has a small-diameter output gear 16a.
b is integrally provided. On the other hand, reference numeral 17 is a counter shaft rotatably supported by the casing 15 via a bearing 18, and a large-diameter input gear 19 which constantly meshes with the output gear 16b is provided at the upper end of the counter shaft 17. The output shaft 16a is integrally fixed, and the rotation of the output shaft 16a is decelerated and transmitted to the counter shaft 17.

The counter shaft 17 is formed with a spline groove portion 17a.
a includes the counter gear 20 and the counter gear 20.
A pair of clutch plates 2 so as to sandwich the upper and lower sides.
1, 22 are fitted and incorporated so as to be movable in the axial direction and freely rotatable, and further, the spline groove portion 17a.
The first and second clutch holders 23 and 24 are movable in the axial direction so as to sandwich the clutch plates 21 and 22 from the upper and lower sides, but are spline-fitted so as to rotate integrally with the counter shaft 17. Therefore, the electric motor 16 is rotated in association with the driving of the electric motor 16. A clutch ammunition 25 is provided between the input gear 19 and the upper first clutch holder 23 of the clutch holder facing the input gear 19, and the first clutch holder 23 is connected to the lower second clutch. It is biased toward the holder 24 side. On the other hand, cam grooves 24a are formed on the lower surface of the second clutch holder 24, that is, the surface facing the casing 15, at intervals of 90 degrees, and the casing 15 has
Cam protrusions 15a are formed facing the cam groove 24a at intervals of 180 degrees. When the cam groove 24a reaches the position of the cam projection 15a due to the rotation of the second clutch holder 24 accompanying the driving of the electric motor 16, the second clutch holder 24 is moved downward so that the cam groove 24a fits into the cam projection 15a. While moving, the first clutch holder 23, the clutch plate 21, the counter gear 20, and the clutch plate 22 are also moved downward by the urging force of the clutch ammunition 25, which causes the clutch ammunition 25 to extend and attach. The force (clutch force) is reduced, and the pressure holding by the clutch holders 23 and 24 is weakened so that the counter gear 20 is allowed to freely rotate with respect to the counter shaft 17. On the other hand, when the cam groove 24a and the cam projection 15a are in a position where they are different from each other,
Along with the second clutch holder 24, the first clutch holder 23, the clutch plate 21, the counter gear 20, and the clutch plate 22 are moved upward, whereby the clutch ammunition 25 is contracted and the urging force is increased. The holders 23 and 24 strongly press and hold the counter gear 20 so that the counter gear 20 is prevented from freely rotating with respect to the counter shaft 17 so that the counter gear 20 rotates integrally with the counter gear 20. The steering gear 26, which is provided as a special purpose, is rotated, and in this embodiment, the friction type intermittent clutch mechanism 27 is formed in this manner.

Reference numeral 28 denotes a detection switch integrally provided on the machine body side, and a switch lever 28a of the detection switch 28 is in contact with a base end portion of a detection rod 29 which penetrates the casing 15 in a removable manner. However, this detection rod 29
Between the tip 29a of the shell and the casing 15, the ammunition 3
0 is interposed, and the detection rod tip end portion 29a is pressed against the counter gear 20. As described above, when the intermittent clutch mechanism 27 is in the continuous state (when the counter gear 20 is moving upward) and when it is in the disconnected state (when the counter gear 20 is moving downward), it can be detected. It is becoming like this.

Reference numeral 31 is a control unit for performing various controls such as forward / reverse drive control of the electric motor 16. The control unit 31 is constituted by using a microcomputer, but the control unit 3
In addition to the detection switch 28, the switch 1 includes a control switch 32 for switching between a manual steering state and an automatic steering state, various switches such as a gyro 33 for recognizing the displacement angle of the machine body, meters and sensors. Signal is input and various control commands are output to the corresponding actuators based on the input data to perform the necessary control. These controls are derived from the main routine as subroutines. However, since then,
The steering control will be described based on the flowchart shown in FIG.

In the steering control pulled out as the above-mentioned subroutine, it is judged whether the control switching switch 32 is in the automatic steering state or the manual steering state, and when it is judged that it is in the manual steering state, the detection switch 28 is used. When the intermittent clutch mechanism 27 determines whether it is in the discontinuous state or the continuous state, and when it is determined that the continuous state is the continuous state, the electric motor 16 is driven (for example, driven in the right steering direction) until the intermittent state is determined. When the state is determined, the electric motor 16 is controlled to stop.

On the other hand, when it is determined that the control switching switch 32 is in the automatic steering state, it is determined whether or not the steering instruction is output, and when it is determined that the steering instruction is not output, The detection switch 28 determines whether the interrupting clutch mechanism 27 is in an interrupted state or an interrupted state. When it is determined that the electric motor 16 is in the disconnected state, the motor 16 is driven (for example, driven in the right steering direction), and when the continuous state is determined, the electric motor 16 is controlled to stop. In this drive control, when a steering command to be described later is output, there is no delay in steering timing as in the case where steering control is performed after the intermittent clutch mechanism 27 is switched from the disconnected state to the continuous state by driving the electric motor 16. This is a consideration for On the other hand, when a steering command for right steering or left steering is output, the electric motor 16 is driven forward and backward to the corresponding side, whereby right steering and left steering are performed.
The output of the steering command is calculated based on the signal from the gyro 33 and is performed based on this, but details thereof will be omitted here.

In the embodiment of the present invention constructed as described above, when manned traveling, the control switching switch 32 may be switched to the manual steering side. In this way, the intermittent clutch mechanism 27 is operated by an electric motor. 16 automatically maintains the disconnection state, and as a result, the driver's manual steering operation by turning the steering wheel 10 can be performed lightly regardless of the reduction mechanism and the electric motor 16. it can. On the other hand, in the case of unmanned traveling, the control switching switch 32 may be switched to the automatic steering side. In this state, if the steering command is output from the control unit 31 and the electric motor 16 is driven in the forward / reverse control mode, the intermittent operation is performed. Clutch mechanism 2
7 is repeated intermittently (the cam groove 24a is fitted into the cam projection 15a in a short disconnection state but in a long continuous state), but automatic steering is performed based on the drive of the electric motor 16. Become.

As described above, in the embodiment of the present invention, the manual steering or the automatic steering can be selected as required, but in the case of the manual steering, the speed reduction mechanism and the steering shafts 12 and 13 are provided. The intermittent clutch mechanism 27 interposed in the switch automatically switches to the disconnected state, and power transmission to the reduction mechanism and the electric motor 16 is cut off. As a result, manual steering becomes light and workability is improved. improves. Moreover, since the switching of the intermittent clutch mechanism 27 is automatically performed in conjunction with the switching of the control switching switch 32, there is no trouble of forgetting to switch unlike the one using a dedicated switching operation tool, and the operability is improved. To do.

Moreover, in this device, the intermittent clutch mechanism 2
The intermittent switching of No. 7 is performed by using the electric motor 16 which is a drive source for automatic steering.
There is no need for a dedicated drive source for switching between, and the structure can be simplified and the number of parts can be reduced. In this configuration, in the automatic steering state, when the intermittent clutch mechanism 27 stops steering at the timing of the interrupted state, the electric motor 16 is driven to control the intermittent clutch mechanism 27 to be in the continuous state. Therefore, there is an advantage that the steering is promptly performed when the next steering command is output and the timing delay is avoided.

It should be noted that the present invention is not limited to the above embodiment, and the interrupting clutch mechanism is
The cam groove and the cam protrusion may be provided in the opposite relationship, and other interrupting clutch mechanism may be adopted, and the interrupting clutch mechanism may be interrupted by using a dedicated drive source. You may do it.

[0018]

In summary, since the present invention is constructed as described above, it is possible to switch between the automatic steering state based on the drive of the drive means and the manual steering state based on the rotation of the steering wheel. In conjunction with the switching of the steering state, the intermittent clutch means interposed between the speed reduction mechanism and the steering shaft switches to automatically switch to the clutch disconnected state in the manual steering state. As a result, although the power of the drive means is transmitted to the steering shaft through the speed reduction means, when in the manual steering state, the steering shaft has a dynamic disconnection with the speed reduction mechanism and the drive means. As a result, the operability of the steering wheel is remarkably light, and the operability is comparable to that without a reduction mechanism and drive means. Moreover, the intermittent switching of the intermittent clutch mechanism is not performed using a dedicated operation tool but is automatically performed in connection with the switching between the automatic steering state and the manual steering state. Switching operation is unnecessary, and there is no trouble caused by forgetting to switch.

[Brief description of drawings]

FIG. 1 is a side view of a seedling transplanting work machine.

FIG. 2 is a sectional view of a steering drive device.

FIG. 3A is a development view of a cam portion in a continuous clutch state, and FIG. 3B is a development view of a cam portion in a disconnected clutch state.

FIG. 4 is a block diagram showing a control mechanism.

FIG. 5 is a flow chart showing steering control.

[Explanation of symbols]

 10 Steering Wheel 12 First Steering Shaft 13 Second Steering Shaft 16 Electric Motor 16b Output Gear 19 Input Gear 27 Intermittent Clutch Mechanism 28 Detecting Switch 32 Control Switching Switch

Claims (1)

[Claims] 1. An automatic steering state based on the drive of the driving means and a manual steering state based on the rotation of the steering wheel, in which a driving means is interlockingly connected to a steering shaft which is turned by manual steering of a steering wheel through a reduction mechanism. In the work vehicle configured to be switched to and, in the power transmission path from the speed reduction mechanism to the steering shaft, in providing an interrupting clutch mechanism for interrupting the power transmission, the interrupting clutch mechanism, In a working vehicle characterized by being provided with a clutch automatic switching means that is linked to switching between a manual steering state and an automatic steering state, and switches to a clutch disconnection state in the manual steering state and to a clutch continuation state in the automatic steering state. Steering drive.