JPS597402B2 - Hydraulic circuit for combine harvester control - Google Patents

Description

[Detailed Description of the Invention] In recent years, combine harvesters have been equipped with hydraulic automatic handling depth control devices and machines that automatically follow the planted culms in order to automatically maintain and adjust the handling depth within a set range. It is being considered that a hydraulic automatic steering control system will be installed to allow the vehicle to proceed.

In addition, in installing each of the automatic control devices, a first hydraulic actuator for automatic handling depth control and a second hydraulic actuator for automatic steering control are driven by oil discharged from one pump. According to this, the overall structure can be made cheaper.

As described above, the present invention provides a first pump with oil discharged from one pump.
Another object of the present invention is to provide a hydraulic circuit for controlling a combine harvester that can accurately drive both hydraulic actuators once when driving the second hydraulic actuator once.

Below, the present invention. An embodiment of this will be described based on illustrative drawings.

Fig. 1 shows a reaping section A at the front of the machine, which has a threshing device 2, etc. mounted on a pair of left and right crawler traveling devices 1a and 1b.
This shows a combine that is connected and equipped.

The reaping unit A uses a front lifting device 3 to raise a plurality of planted stem culms in a bow 1, and a reaping device 4 to reap the base end of the plant, and then, as shown in FIG. Using the device 5, the harvested stem culms are conveyed to one side laterally and merged, and the merging stem culms are supported in an inclined posture with the tip side of the stem being deviated towards the inside of the body rather than the plant base side,
Subsequently, the stalks are transported rearward by a vertical transport section consisting of the ear tip locking transport device 6a and the stock head clamping transport device 6b, and after changing to a sideways posture at the end of transport, the stem culm stock base is transferred to a threshing device. It is configured to deliver to the feed chain 7 of No. 2.

Further, this combine harvester is equipped with a hydraulic automatic cutting height control device described below in order to maintain the height of the reaping section A above the ground within a certain range, and to maintain the cutting height within a certain range.

That is, the reaping section A is supported via an elevating frame 8 that is pivotally connected to the machine so as to be able to swing up and down, and a hydraulic cylinder 9 is interposed between the elevating frame 8 and the machine. , is configured to be telescopically operated by switching the electromagnetic three-position switching valve V1 (see Fig. 5), and thus,
It is configured to be forcibly lifted when the cylinder 9 is in a forcedly extended state, lowered by its own weight when the cylinder 9 is in a freely extended or contracted state, and fixed and held at a desired position when the cylinder 9 is in a fixed lock state.

On the other hand, the reaping section A is equipped with a ground sensor 10 that is rotatable around a horizontal axis, and is pressed against the sensor 10, which swings as the height of the reaping section A changes from the ground. A pair of switches S1 and S2 are provided.

These switches S1 and S2 are connected to a solenoid section that changes the position of the spool of the switching valve (1).
When the switch S1 is brought into contact with the height of the reaping section A above the ground as it becomes higher than the desired position range, the hydraulic cylinder 9 enters a freely expanding and contracting state, and the height above the ground of the reaping section A becomes lower than the desired position range. When the switch S2 is brought into contact with the switch S2, the hydraulic cylinder 9 is extended, and furthermore, when the height of the reaping section A from the ground is within the desired height range, both the switches S1 and S are activated.
2 are held in a non-operating state, and the cylinder 9 is fixedly locked.

Therefore, when the height of the reaping section A changes due to the presence of unevenness in the field, the ground sensor 10 detects this by its rocking displacement, and if the detected value increases or decreases by more than a certain level, the hydraulic cylinder 9 is controlled and the reaping section A is raised and lowered, thereby automatically maintaining the height above the ground within a certain range.

In addition, this combine harvester can handle the threshing device 2 regardless of the length of the stem culm.
In order to maintain the amount of insertion within a set range, a hydraulic automatic depth control device described below is provided.

That is, the ear tip locking and conveying device 6a and the stock head clamping and conveying device 6b are pivotally connected at their rear end sides near the pivot point of the elevating frame 8, and as shown in FIG. As the hydraulic cylinder 11 supported by the stem culm expands and contracts, the front end thereof is swung along the culm length direction of the stem culm supported by the auxiliary conveyance device 5 via a link mechanism. With this vertical swing, the gripping position of the stem culm delivered from the auxiliary conveyance device 5 is changed to the culm length direction, and the stem culm, which is supported and conveyed by the feed chain T, is inserted into the G threshing device 2. It is configured to perform so-called handling depth adjustment, which is to change the amount of insertion of the stem culm.

In addition, as shown in FIG. 3, a curved shape for supporting the clamping rail 6' of the stock clamping and transporting device 6b is arranged so as to bypass the tip side of the stem culm being transported by the tip locking and transporting device 6a. A mechanism for electrically detecting the length of the transported grain culm is provided inside the frame 12.

This detection mechanism consists of a case 1 attached to the frame 12.
Three swing sensors 14a, 14b, and 14C are pivoted along the culm length direction, and each sensor 14
a... are equipped with switches T1, T2, and T3 that operate in accordance with the swinging of the sensors 14a...

Incidentally, the stock support rail 6' is also equipped with a swing sensor 14d equipped with a switch T4 similar to that described above.
4a... Mounted on the extension line of the row, and configured to function as a starting switch for controlling the handling depth, which will be described later.

On the other hand, the hydraulic cylinder 11 has an electromagnetic three-position switching valve ■
The switching valve (2) is oil-filled and expands and contracts when the switching valve (2) is in the neutral state, and is fixedly locked at a desired position when the switching valve (2) is in the neutral state.

Then, as the switching valve V2 is controlled as follows based on the culm length detection result, the cylinder 11 is operated to expand and contract, thereby maintaining the handling depth.

In other words, the operator must first and second sensor 14a and second sensor 1
4b, control is performed to maintain the deep handling state in which the tip of the grain culm passes between the first sensor 14a and the second sensor 14b, and the grain is When the tip of the culm exceeds the first sensor 14a, the switch T1 is activated, which activates the solenoid 2, which controls the shallow handling side. When T2 is activated, the solenoid of the switching valve v2 is activated, and control to the deep handling side is performed.

In addition, the operator also uses the second sensor 14b and the third sensor 14c.
If the state is switched to the state in which the grain culm is used, control is performed to maintain the shallow handling state in which the conveyed grain culm tips pass between the second sensor 14b and the third sensor 14c.
Similarly to the above, when the tip of the grain culm exceeds the second sensor 14b, control is performed to the shallow handling side, and the third sensor 14
If it deviates below c, control is performed to the deep handling side.

Further, this combine harvester is equipped with a hydraulic automatic steering control device, which will be described below, in order to automatically run the combine harvester while following the planted stem culms.

That is, as shown in FIG. 4, on both sides of the stem culm introduction path B formed along one lateral side of the pulling device 3,
A pair of sensors 15a and 15b are provided as a mechanism for detecting the lateral deviation of the machine body with respect to the introduced planted stem culm.

These sensors 15a and 15b are elastically biased into a protruding posture that crosses the path B, and as the stem culm swings backward due to contact with the stem culm, the stem culm moves to one side of the path B or to the other side. It is configured to detect that the vehicle has deviated to the side and to operate the switch U1 or U2 when the vehicle swings backward significantly.

On the other hand, the crawler traveling devices 1a and 1b are driven by an output transmitted from a mission case (not shown) that is linked to an installed engine E (see FIG. 1), and are equipped within the mission case. A pair of left and right steering clutch brakes (not shown) are connected to a pair of hydraulic cylinders 16.
a, 16b (see FIG. 5) are alternatively operated by the alternative extension operation, an alternative drive state is created, and the aircraft is configured to be steered. ing.

When the switch U1 or U2 is operated by the detection operation of the rocking sensors 15a, 15b, an intermittent signal is generated to the solenoid section of the electromagnetic switching valve (3) that controls the operation of the hydraulic cylinders 16a, 16b. The machine is configured to be energized intermittently by the action of the switch 17, so that when the switch U1 or U2 is operated, steering control is automatically performed so that the machine follows the planted stem culm.

Further, the hydraulic automatic handling depth control device, the hydraulic automatic steering control device, and the hydraulic automatic cutting height control device include:
As shown in FIG. 5, it is driven by one hydraulic pump P linked to the engine E, and its drive structure will be described below.

That is, a flow priority valve (Flowpriority Val-ue) 1 is provided that always makes the flow on the control output port PF side constant in the discharge oil path a of the hydraulic pump P, and makes the surplus output port EF a bypass flow.
The switching valve v1 of the automatic cutting height control device is connected to the control output port PF side of this valve 18, and the automatic cutting depth control device is connected to the surplus output port EF side of this valve 18. The switching valve (2) of the device and the switching valve (2) of the automatic steering control device are connected with the switching valve (2) positioned on the upper side.

Further, the oil supply side oil passage b1 and the oil discharge side oil passage b2 of the switching valve (2) are connected to each other via a throttle valve 19, and the throttle valve 19 connects the hydraulic cylinder of the automatic handling depth control device 1
By providing just enough resistance to ensure the operation of 1,
Although both the switching valves (2) and (3) are connected in series, the automatic handling depth control device and the automatic steering control device can operate simultaneously.

In the embodiment, a case was illustrated in which the automatic cutting height control device was also driven by using the flow priority valve 18, but it could also be implemented by simply driving the automatic cutting depth control device and the automatic steering control device. Of course, you can do it.

In addition, when using the priority valve 18 in this way, as shown in FIG. It is a good idea to switch the settings accordingly.

In other words, when there are many irregularities in the field, a cutting height control device is connected to the control output port PF in order to accurately control the cutting height and avoid contact between the reaping part and the convex parts of the field. , On the contrary, when the rows of planted stems and culms are disordered,
In order to accurately control steering and prevent uncut leaves,
It is preferable to connect the steering control device side to the control output port PF.

In summary, the hydraulic circuit for controlling a combine harvester according to the present invention uses the oil discharged from one hydraulic pump as described above.
In order to drive the first and second hydraulic actuators, the first
A first control valve of the hydraulic actuator and a second control valve of the second hydraulic actuator are connected in series with the first control valve on the upper side, and an oil supply side oil passage and an oil discharge side oil passage of the first control valve are connected in series. are in communication with each other via a throttle valve that provides sufficient resistance to ensure the operation of the first hydraulic actuator.

In other words, a part of the supplied pressure oil is used for the first hydraulic actuator for handling depth control, which requires a relatively small amount of driving force, while the first hydraulic actuator is used for steering control, which requires a relatively large amount of driving force. The entire amount of pressure oil is supplied to the second hydraulic actuator, making it possible to always properly operate both hydraulic actuators with the oil supplied from one pump.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the hydraulic circuit for controlling a combine harvester according to the present invention, with FIG. 1 being a side view of the combine, FIG. 2 being a schematic side view of the reaping section, and FIG. 3 showing a curved frame portion. 4 is a schematic front view showing the rocking sensor mounting part, FIG. 5 is a hydraulic circuit diagram, and FIG. 6 is a hydraulic circuit diagram of another embodiment. 11...First hydraulic actuator, 16a, 1
6b...Second hydraulic actuator, 19...
... Throttle valve, ■2... First control valve, ■3
...Second control valve, b1... Oil supply side oil path, b2... Oil drain side oil path, P... Hydraulic pump.

Claims (1)

[Claims] 1. When the first hydraulic actuator 11 for automatic handling depth control and the second hydraulic actuators 16a, 16b for automatic steering control are driven once with discharge oil from one hydraulic pump P, the first hydraulic actuator 11 1st control valve■
2 and the second control valve ``3'' of the second hydraulic actuators 16a, 16b are connected in series with the first control valve ``2'' on the upper side, and the oil supply side oil passage b1 and the oil discharge side of the first control valve V2 are connected in series. A hydraulic circuit for controlling a combine harvester, characterized in that it communicates with an oil passage b2 via a throttle valve 19 that provides sufficient resistance to ensure the operation of the first hydraulic actuator 11.