JPH0730419Y2 - Rotating device for mobile agricultural machinery - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a turning device that can be applied to a mobile agricultural machine such as an agricultural tractor or a rice transplanter that requires a small turn.
The present invention relates to a turning device for a mobile agricultural machine that can reduce the turning radius of the machine body.

[Prior art]

Conventionally, as shown in FIG. 18, when the aircraft turns, the turning radius FR from the turning center O to the left and right front wheels 1 is changed to the turning radius O from the turning center O to the left and right rear wheels 2. Since the radius is larger than the radius RR, the actual situation is that the aircraft is turning based on the turning radius of the front wheels 1.

[Problems to be solved by the invention]

By the way, as described above, if the turning radius FR of the front wheels is used as a reference, there is a problem that the turning radius of the vehicle body becomes large and a small turn cannot be performed.

Further, as shown in FIG. 18, since the turning radii of the front wheel 1 and the rear wheel 2 are different, the front wheel 1 is pushed by the rear wheel 2 even in the four-wheel drive system, and the driving force of the front wheel 1 is However, there was a problem that the degree of contribution to the traction force of the aircraft was low.

Furthermore, since the front wheel 1 is pushed from the rear wheel 2,
In a weak field, mud pushing by the front wheels 1 occurs and the field is rough.

Therefore, the present invention was devised to solve the above-mentioned conventional problems.By sliding the front axle laterally toward the turning center side, the aircraft can make a small turn and the mud pushing by the front wheels is prevented. The present invention is carried out for the purpose of providing a turning device for a mobile agricultural machine.

[Means for solving problems]

A turning device for a mobile agricultural machine according to the present invention that achieves the above object holds a front axle supporting a front wheel that is steered by turning a steering handle in a straight-ahead position at the center of the machine body, depending on a turning position. It is configured to laterally slide toward the turning center side of the machine body.

[Action]

Therefore, in the straight-ahead position, the center of the machine can be prevented. "
As described above, "the present invention is configured as described above, and the front axle held in the center of the machine body in the straight-ahead position is laterally slid toward the center of the machine body in the turning direction according to the turning position. Since the front wheel can be moved closer to the center of turning to reduce the turning radius, the turning radius of the airframe can be reduced to enable a small turning turn.

Also, since the turning radius of the front wheels can be reduced,
Both front and rear wheels can be moved on the same radius locus, and even with four-wheel drive, the front wheel can be increased in traction without being pushed by the rear wheels as in the past, and it is soft. Since it is possible to eliminate the mud pushing state by the front wheels in a rough field, it is possible to prevent the field from becoming rough.

〔Example〕

Hereinafter, the drawings showing the present invention as an embodiment will be described.

9 to 10, an agricultural tractor T is provided with an engine 4 covered by a bonnet 3 in front of the machine body, and a transmission 5 having a front end fixed to a rear end of the engine 4 extends rearward. The engine 4 and the transmission 5 constitute a machine body of the agricultural tractor T. A pair of left and right rear wheels 2 are pivotally supported behind the transmission 5, and the left and right rear wheels 2 are provided in the transmission 5 through a differential mechanism (differential mechanism, differential mechanism) (not shown). Mechanism)), and the turning side is braked by the brake during turning.

A front axle 7 is arranged below the engine frame 6 whose base end is fixed to the engine 4 and extends forward. As shown in FIGS. 1 and 2, front wheel cases 9 are provided on the left and right sides of the front axle 7 so as to be swingable in the front-rear direction about the kingpin axis K in the obliquely vertical direction. The front wheels 1 pivotally supported by the front wheel case 9 are driven via a propeller shaft (not shown) driven by the transmission 5 and a diff mechanism in the front axle 7 driven by a universal joint.

The left and right front wheel cases 9 swing integrally around the kingpin axis K by pivotally connecting the knuckle arms 10 of the front wheel cases 9 with tie rods 11. The tie rods 11 are longitudinally intermediate. The part is interlocked with a spherical joint 13a protruding to the lower end of the drive arm 13 that swings in the left-right direction in conjunction with the operation of the double-acting hydraulic cylinder 12, and the rotation of the machine body is changed depending on the turning position. The front wheel steering device laterally slides toward the center side, that is, in this first embodiment, the entire front axle 7 laterally slides toward the turning center O side in proportion to the turning angle of the front wheel 1.
It is composed of fifteen.

Explaining the details of the front wheel steering device 15, the above-described double-acting hydraulic cylinder 12 is arranged in a support frame 16 having a downward U-shaped cross section, which is fixed below the engine frame 6 in the left-right direction. The hydraulic cylinder body 12a is fixed to the support frame 16 by mounting bolts. Piston shaft protruding from the inside of this hydraulic cylinder 12 to the left and right sides
12b is fixed to the inside of the upward end portions 17a on both the left and right sides of a moving frame 17 having a U-shape in a front view, which is provided slidably on both sides in the support frame 16, by means of mounting bolts. An interlocking frame 19 having a mounting shaft 20 extending rearward is fixed to an intermediate portion in the longitudinal direction of 17, and the mounting shaft 20 of the interlocking frame 19 is provided above the fulcrum hole of the drive arm 13. The long holes are fitted and connected.

The drive arm 13 has a fulcrum hole provided at a substantially middle portion in the lengthwise direction, which is pivotally attached to a fulcrum shaft 23 extending forward from a fixed frame 22 fixed below the engine frame 6, The lower end of the tie rod 11 is connected to an intermediate portion in the longitudinal direction.

Further, the front moving frame 17 has an upper end of a mounting bracket 25 fixed to the lower part in the longitudinal center thereof, and the mounting bracket 25 and the front axle 7 are pivotally connected to each other via a fulcrum shaft 26 extending in the front-rear direction. The axle 7 is configured such that the left and right sides thereof are vertically swingable about the axis of the fulcrum shaft 26.

Further, as shown in FIG. 17, the steering handle 27 mounted in front of the driver's seat provided on the agricultural tractor T is the steering handle 27.
It is connected to the switching valve 36 via a metering pump 39 connected to. Since FIG. 17 is also used for the hydraulic circuit of the second embodiment, hereinafter, the oil passage A and the oil passage B are directly connected to the hydraulic cylinder 12 without passing through the switching valve 34.
The structure connected to will be described.

Therefore, since the switching valve 36 is switched and controlled by the pressure generated by the metering pump 39 by the turning operation of the steering handle 27, the hydraulic pump is provided in either the left or right chamber of the hydraulic cylinder 12 with respect to the direction to be turned. By sending pressure oil from 35 through metering pump 39, front axle 7
Is laterally slid in proportion to the turning amount of the steering handle 27, that is, the turning angle of the front wheel 1.

As shown in FIGS. 1 and 2, when the steering handle 27 is not rotated, the metering pump 39 keeps the switching valve 36 in the neutral state and the front axle 7 supporting the front wheel 1 is in a straight state. , The center S of which is held by the hydraulic cylinder 12 at the center of the machine body which coincides with the center line C of the machine body, but when the steering handle 27 is rotated rightward, for example,
As shown in FIGS. 4 to 5, the front axle 7 laterally slides toward the right side of the machine body center line C, that is, toward the turning center O on the right side, and the tie rod 11 moves to the left side so that the front wheel 1 moves. Steered clockwise.

That is, when the steering handle 27 is rotated to the right, the switching valve 36 is switched and controlled by the generated pressure of the metering pump 39, and the hydraulic fluid of the hydraulic pump 35 is laterally directed to the piston shaft 12b of the hydraulic cylinder 12 to the right. To slide. The front axle 7, which is integrally connected to the moving frame 17 that moves laterally to the right in conjunction with this, has the center S of the body centerline C.
At the same time, the interlocking arm 13 centered on the fulcrum shaft 23 moves to the right by a distance L, and the lower part moves to the left side by moving the upper part to the right side, so that the tie rod 11 connected to the lower part of the interlocking arm 13 moves. The vehicle moves to the left and the front wheel 1 is steered to the turning angle in the clockwise direction.

If the steering handle 27 is rotated leftward from the straight-ahead state, the direction is opposite to that described above.

As described above, when the aircraft is turned, the front axle 7 is proportional to the turning amount of the steering handle 27, that is, the turning angle of the front wheels 1.
Since the vehicle laterally slides to the turning center O side of the airframe, as shown in FIG. 8, the turning radius FR from the turning center O on the right side to the front wheel 1 is FR.
Then, the turning radius of the machine body can be reduced by the amount that the front axle 7 laterally slides so that the turning radius RR from the turning center O to the rear wheel 2 becomes substantially the same, and the machine body can turn in a small turning state.

Further, in the turning state of the aircraft, the front and rear wheels 1 and 2 both move on the same radius locus, so that in the four-wheel drive state, the front wheel 1 is not pushed to the rear wheel 2 side unlike the conventional case, and the front wheel 1 side is not pushed. The traction force can be increased, and at the same time, the mud pushing state by the front wheels 1 in the soft field is prevented, and the field is not roughened.

When the steering handle 27 is returned to the straight traveling state when the turning of the machine body is completed, the oil flow by the metering pump 39 is reversed and the switching valve 36 is switched in the reverse direction. 12b moves to the left. In parallel with this, the front frame 7 integrally connected to the moving frame 17 that has moved to the left moves to the left, and at the same time, the front arm 7 that is swinging around the fulcrum shaft 23 is interlocked with the tie rod.
11 also moves to the right, and the front wheel 1 is returned to the left.

Then, when the front wheels 1 and the front axle 7 return to the straight traveling state, the metering pump 39 switches the switching valve 36 to the neutral position, so that the front axle 7 is held in the straight traveling position by the hydraulic cylinder 12.

Next, FIGS. 11 to 17 showing the second embodiment will be described.

In the second embodiment, the front axle 7 held at the central position is moved to the front wheel 1 without simultaneously operating the steering of the front wheel 1 and the lateral sliding of the front axle 7 as in the previous example.
Is designed to slide laterally only at a turning angle of a predetermined angle or more.

That is, in the OFF state of the switching switch 32 shown in FIG.
The front axle 7 is held in the center of the machine body so that the turning operation can be performed only by the turning angle of the front wheel 1, and when the switching switch 32 is in the ON state, only when the turning angle of the front wheel 1 becomes a predetermined angle or more, Both the turning angle steering of the front wheels 1 and the lateral sliding toward the turning center O side of the front axle 7 can be performed at the same time.

As shown in FIGS. 11 to 13, a double-acting hydraulic cylinder 30 different from the hydraulic cylinder 12 for laterally moving the front axle 7 is provided.
The hydraulic cylinder body 30a is fixed to the front axle 7, and the piston shafts 30b projecting to the left and right sides of the hydraulic cylinder body 30a are connected to the knuckle arm 10 of the front wheel case 9 via tie rods 31 pivotally connected to the piston shafts 30b.
It is configured for steering front wheels pivotally connected to.

As described above, since the hydraulic cylinder 30 for front wheel steering is provided separately from the hydraulic cylinder 12 for lateral sliding of the front axle 7, the moving frame 17 and the tie rod 11 are connected to each other as in the previous example. The drive arm 13 is not necessary, but the switching switch 32 installed on the operation panel section for disconnecting the interlocking with the front axle 7 and switching to the steering state of only the front wheel 1 and the disconnection of the front wheel 1 over a predetermined angle. A detection switch 33 for detecting an angle and a switching valve 34 operated by the detection switch 33 are arranged as shown in FIGS. 16 to 17, and the solenoid 34a of the switching valve 34 is in the ON state of the detection switch 33. Operate.

Therefore, the hydraulic pump 35 shown in FIG.
However, when the switching switch 32 is OFF, the switching valve 34 is in the neutral state, so the pressure oil from the hydraulic pump 35 is not supplied to the hydraulic cylinder 12 side.
It is supplied only to the hydraulic cylinder 30 via the switching valve 36 which is switched and controlled by the metering pump 39 interlocked with the turning operation of the steering handle 27, and the front wheel 1 is cut off by the operation of the steering handle 27. Only corner operations can be performed.

Reference numeral 37 in FIG. 17 is a check valve, and 40 is a steering unit.

Therefore, when the steering handle 27 is steered to the right, for example, the metering pump 39 switches the switching valve 36 as shown in FIG. 17A, the pressure oil from the hydraulic pump 35 flows in the arrow direction, and the hydraulic cylinder 30 On the other hand, since the piston 30b moves to the left, the front wheel 1 is steered to the turning angle in the clockwise direction.

Even when the switching switch 32 is turned on, the detection switch 33 is in the off state at the turning angle within the predetermined angle of the front wheel 1, so that only the hydraulic cylinder 30 for steering the front wheels is operated and the center of the machine body is operated as described above. Only the turning angle steering of the front wheels 1 can be performed by the front axle 7 held by. However, when the switching switch 32 is switched to the ON state and the front wheel 1 is steered at a turning angle of a predetermined angle or more, the detection switch 33
When is turned on, the solenoid 34a is operated and the switching valve 34 is switched to the switching position, so that the hydraulic pressure from the hydraulic pump 35 also flows to the hydraulic cylinder 12 for moving the front axle, and the hydraulic cylinder 30 that is already in operation. In addition to this, the hydraulic cylinder 12 also operates. That is, when the predetermined front wheel turning angle is reached, the front axle 7 is controlled so as to laterally slide toward the turning center O side of the machine body in proportion to the turning angle of the front wheel 1 cut thereafter.

As described above, at the turning angle of the front wheel 1 within the predetermined angle, the front axle 7 is held at the center position in the straight traveling state and does not slide laterally. Therefore, the turning operation of the steering handle 27 in the straight traveling state within the small angle is performed. The direction of the aircraft can be corrected only by operating the turning angle of the front wheels 1. However, switch 32 is turned on.
When the state is changed to the state where the steering wheel 27 turns the front wheel 1 at a predetermined angle or more when changing the direction of the machine body on the headland, etc., in addition to the front wheel steering hydraulic cylinder 30, the front axle moving hydraulic cylinder is moved. 12 also works, Fig. 14-Fig.
As shown in FIG. 15, since the front axle 7 laterally slides toward the turning center O side, the turning radius of the aircraft can be reduced by the amount of this lateral sliding, and the child can turn the aircraft in a small turning state. .

Further, when the steering handle 27 is returned to the straight traveling state at the time when the turning of the machine body is completed, the flow of the oil by the metering pump 39 is reversed and the switching valve 36 is switched in the reverse direction. The piston shaft 12b of 12 moves to the left and the front axle 7 laterally slides to the left, and at the same time, the piston shaft 30b of the hydraulic cylinder 30 moves to the right and the front wheel 1 is returned to the left. Then, when the front wheel 1 returns to the turning angle of the predetermined angle, the detection switch 33 is turned off and the switching valve 34 is set to the neutral position, whereby the front axle 7 is held in the straight traveling state in the center of the machine body by the hydraulic cylinder 12. , Then the steering wheel 27 is returned to the front wheel 1
Is returned to the straight traveling state, the metering pump 39 switches the switching valve 36 to the neutral state, so that the front wheels 1 are kept in the straight traveling state.

[Effect of device]

As described above, according to the present invention, the front axle, which is held in the center of the machine body in the straight-ahead position, is slid laterally toward the center of the machine body turning direction according to the turning position. The direction radius can be reduced, and the aircraft can be turned in a small turning state.

Also, since the turning radius of the front wheels can be reduced,
Both front and rear wheels can be moved on the same radial locus, and even with four-wheel drive, the front wheel can be increased in traction force without being pushed by the rear wheels as in the conventional case, and it is weak. Since the mud pushing condition by the front wheels in the field is eliminated, the soft field is not damaged.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a plan view of a front axle, FIG. 2 is a front view of FIG. 1, FIG. 3 is a side view of essential parts, and FIG. FIG. 5 is a plan view of the front axle shown in FIG. 5, FIG. 5 is a front view of FIG. 4, FIG. 6 is a perspective view of a support frame, FIG. 7 is a side view of the support frame, and FIG. FIG. 9 is an overall side view of the agricultural tractor, and FIG. 10 is a front view of the agricultural tractor. 11 to 17 show a second embodiment, FIG. 11 is a plan view of a front axle, FIG. 12 is a front view of FIG. 11, FIG. 13 is a side view of a main part, and FIG. FIG. 15 is a front view of FIG. 14, FIG. 16 is an electric circuit, FIG. 17 is a hydraulic circuit diagram showing a neutral state, and FIG. 17A is a right-turning state. FIG. 3 is an operation explanatory view of the hydraulic circuit showing FIG. FIG. 18 is a diagram for explaining the turning state of the airframe in the conventional example. T: agricultural tractor, 1 front wheel, 2 rear wheel, 7
Front axle, 11 …… Tyrod, 12 …… Hydraulic cylinder, 12a …… Hydraulic cylinder body, 12b …… Piston shaft,
13 …… Drive arm, 16 …… Support frame, 17 …… Movement frame, 25 …… Mounting bracket, 27 …… Steering wheel,
30 …… hydraulic cylinder, 30a …… hydraulic cylinder body, 30b…
… Piston shaft, 34 …… Switching valve, 35 …… Hydraulic pump,
36 …… Switching valve, 39 …… Metering pump.

Claims (3)

[Scope of utility model registration request] 1. A front axle supporting a front wheel steered by rotation of a steering handle is held in the center of the machine body in a straight-ahead position, and laterally slid toward a center side of the machine body in accordance with a turning position. A turning device for a mobile agricultural machine configured as described above. 2. The turning device for a mobile agricultural machine according to claim 1, wherein the front axle laterally slides in proportion to the turning angle of the front wheels. 3. The turning device for a mobile agricultural machine according to claim 1, wherein when the front axle reaches a predetermined front wheel turning angle, the front axle is slid laterally in proportion to the cutting angle of the front wheel. .