JPS5934081B2 - Safety device for power transmitting joint shaft in power agricultural machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power agricultural machine that is capable of raising and lowering the working machine connected to the power agricultural machine using a hydraulic lifting device while transmitting rotational power to drive the working machine. This invention relates to a safety device for preventing damage to a power transmitting universal joint shaft for transmitting rotational power to.

For example, in plowing work, when lifting a working machine to perform turning work on a headland while rotating the tilling body of the working machine, the PTO shaft of the power agricultural machine and the input shaft of the working machine are connected. The joint shaft rotates from the knuckle pins of the front and rear joint bodies while bending greatly relative to the PTO shaft and input shaft, respectively. Therefore, when the lifting height becomes excessive, the universal joint shaft cannot be moved smoothly. The current situation is that it stops rotating and requires a great mental burden to carefully avoid such an excessive rise.

A device configured to raise and lower a working machine within a certain height is known as Utility Model Application No. 51-120219, but this known device operates independently of the rotation of the working machine. However, the above-mentioned known device is still insufficient to be applied as a safety device in a usage state in which lifting and lowering operations are performed while the working machine is rotating.

Therefore, the present invention proposes a safety device for a power transmitting joint shaft when raising and lowering a working machine while it is being rotated, and the following technical measures have been taken for this purpose.

That is, in a power agricultural machine in which a working machine 2 whose vertical position with respect to a power agricultural machine 1 can be freely adjusted by a hydraulic lifting device 5 is connected, and rotary power is transmitted to this working machine 2,
When there is a command to transmit rotational power to the work equipment 2 and the above-mentioned vertical position exceeds a predetermined height that can ensure smooth transmission of the rotational power, the above-mentioned hydraulic lifting is performed regardless of the command to raise the work equipment 2. This is a configuration of a safety device for a power transmitting joint in a power agricultural machine, which is provided with an operation stop portion 35 that operates to stop the lifting operation by the device 5.

With this configuration, the present invention was able to obtain the following technical effects.

That is, there is a command to transmit rotational power to the working machine 2, and
When the vertical position of the work implement 2 exceeds a predetermined height that can ensure smooth transmission of the rotational power, an operation is performed to stop the upper valve operation by the hydraulic lifting device 5 regardless of the command to raise the work implement. Since the stop part 35 is provided, for example, when turning around near a headland, the work implement 2 can be raised while being driven to exceed a predetermined height that ensures smooth transmission of rotational power. In this case, the operation stop section 35 operates to automatically stop the lifting operation of the working machine 2, and the present invention does not require any lifting stop operation under operator control as in the conventional case. , less fatigue for operation;
In addition, the smooth transmission of rotary power to the working machine 2 is always maintained, and, for example, frequent turning operations near headlands can be easily performed with good operability. Note that when the power transmission to the work equipment 2 is not instructed, the operation stop section 35 does not operate.
The working machine 2 can be lifted to a sufficiently high position within the operating range of the hydraulic lifting device 5.

Next, one embodiment of this invention will be explained based on the drawings.
The working machine 2 is connected to the rear of the power agricultural machine 1 with a horizontal hitch pin 3, and the lift arm 6 of the hydraulic lifting device 5 provided at the rear of the transmission case 4 is moved up and down, and the lift arm 6 is pivoted. The working machine 2 is raised and lowered by the attached lift rod γ, and the input shaft 9 protrudes from the front of the PTOTaO2 industrial machine 2 that protrudes from the rear of the mission case 4.
The tilling body 11 of the working machine 2 is connected with the universal joint shaft 10.
A feedback lever 12 is provided to feed back the vertical movement of the lift arm 6 to the hydraulic lifting device 5, as shown in FIG. The electromagnetic solenoid 14 is attached to the link case 13 of the hydraulic lifting device 5, and the operating rod 1 of the electromagnetic solenoid 14 is
4a is connected to the pin 15 inserted into the elongated hole 12a, and P
The PTO lever 16 that intermittently controls the TOTaO2 rotation is PT.
A switch 1γ is provided whose contacts are closed when the O-axis is at the 8-axis rotation position, and a switch 18 whose contacts are closed by a cam 6a protruding from the rotational base of the lift arm 6 is provided as the switch 1γ. They are connected in series so that when the contacts of these switches 1γ and 18 are closed, the electromagnetic solenoid 14 is energized from the power source 19, and when the work equipment 2 is raised as shown in Fig. 2A. PTQ
If the lift arm 6 rotates beyond the lifting limit at which the universal joint shaft 10, which has an increased bending angle with respect to the shaft 8 and the input shaft 9, can rotate smoothly, the cam 6a closes the switch 18, and the PTO lever 16 When is in the position where PTOTaO2 is rotated, the electromagnetic solenoid 14 is activated and the operating rod 14a moves along the arrow A.
Since the feedback lever 12 is pulled in the direction shown in FIG. As a result, the operating lever 21 also returns to the direction of arrow C, and the spool 25 returns to the work machine neutral position as shown in Fig. 3, and the lifting movement of the work machine 2 is stopped. A stop portion 35 is provided.

That is, in FIG. 2A, the operating lever 23 is manually rotated in the direction of the arrow B, so it is attached to the shaft 24 as one unit with the operating lever 23, and is in the position rotated in the direction of the arrow B. Since the operating lever 21 pushes the spool 25 to the right in the figure, the pressure liquid sent from the tank 26 by the hydraulic pump 2γ passes through the passage of the valve body 28 as shown by the arrow E and reaches the spool 25. The on-off valve 29 is pushed to the right from the small diameter portion 25a of the tank 26 to close the return path 30 to the tank 26, and this pressure fluid pushes open the check valve 31 to the right and flows into the hydraulic cylinder 32. The piston 33 moves the lift arm 6 up and around, but if the electromagnetic solenoid 14 is now energized, the lever pin 22 will return to the direction of the arrow C in FIG. 25 moves to the left, thus causing the spool 25 to move to the left, as shown in FIG.
The large diameter portion 25b closes the passage to the back side of the on-off valve 29, so the on-off valve 29 moves to the left and a return path 30 is opened, and the pressure liquid from the hydraulic pump 2γ is transferred from this return path 30 to the tank 26. The liquid supply to the hydraulic cylinder 32 is stopped in order to return to
As a result, the upward rotation of the lift arm 6 is stopped.

Also, instead of the above-mentioned embodiment of the operation stop section 35 that returns the spool 25 to the neutral position by the operation of the electromagnetic solenoid 14, it is possible to install a valve between the liquid feed pipe from the valve body 28 to the hydraulic cylinder 32 to the tank 26. Although not shown, a bypass valve is provided, and this bypass valve is opened by the excitation operation of an electromagnetic solenoid that operates in the same manner as the electromagnetic solenoid 14 described above, and the liquid supply to the hydraulic cylinder 32 is stopped and the lift arm 6 is opened. The movement stopping section 35 may be configured to stop the rising of the movement stop section 35, and various types of movement stopping sections 35 can be used.

Therefore, if the PTO lever 16 is rotated and the PTO shaft 8 is rotated while the operating lever 23 is used to instruct the work equipment 2 to rise, the operation will continue as usual until it reaches a height that does not interfere with the rotation of the universal joint shaft 10. Although the work equipment 2 is a device that rises,
When the allowable rise limit for the work equipment 2 is exceeded, the cam 6a closes the switch 18, so the electromagnetic solenoid 14 is immediately energized and stops sending liquid to the hydraulic cylinder 32, thereby preventing the work equipment 2 from rising excessively. It is something that can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of a powered agricultural machine to which the safety device of the power transmitting joint shaft according to the present invention is applied, Fig. 2 A and Fig. 3
The figures are longitudinal sectional front views of the main parts of the same safety device. FIG. 3 is a partially cutaway side view in FIG. Code explanation 1...Power agricultural machinery, 2...Work equipment, 3...Hitchi pin, 4...Mission case, 5...Hydraulic pressure Lifting device, 6...
...Lift arm, 6a...Cam, γ...
...Lift arm, 8...PTO axis, 9...
...Input shaft, 10... Universal joint shaft, 11...
... Cultivating body, 12 ... Feedback lever, 12 a-4L13 ... Link case, 1
4... Electromagnetic solenoid, 14a... Operating rod, 15... Pin, 16... Sharpening lever, 1γ, 18... Switch, 19...
・Power supply, 20.24...Axis, 21...
Operating lever, 22... Lever pin, 23...
...Operation lever, 25...Spool, 25a
...Small diameter part, 25b...Large diameter part, 26
... Tank, 2γ ... Hydraulic pump, 2
8...Valve body, 29...Opening/closing valve, 30.
...Return path, 31...Change valve,
32... Hydraulic cylinder, 33... Hydraulic cylinder, 34... Return spring, 35...
・Operation stop part.

Claims (1)

[Claims] 1. In a powered agricultural machine that is connected to a working machine whose vertical position can be freely adjusted with respect to the powered agricultural machine by a hydraulic lifting device and transmits rotational power to the working machine, there is a command to transmit the rotational power to the working machine, and an operation stop part that operates to stop the lifting operation by the hydraulic lifting device regardless of the lifting command of the work equipment when the vertical position exceeds a predetermined height that can ensure smooth transmission of the rotational power. A safety device for a power transmitting universal joint shaft in a powered agricultural machine.