JP2896501B2 - Steering device for transporter in the field - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device for a transport machine in a field.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 9 to 11, for example, a front frame 2F having a steering wheel 3 and two front wheels 10, 11 and a vertical pin 71 behind the front frame 2F. Two rear wheels 1 that are rotatably connected
An in-field transporter AO including a rear frame 2R having the rear frames 2 and 13 is known.

As a conventional steering device 81 employed in such an in-field transport machine AO, there is, for example, one provided with a multiple link mechanism 82 provided on the front frame 2F. This multiple link mechanism 82 is, as shown in FIG.
The clockwise or counterclockwise rotation of the handle shaft 42 with the steering wheel 3 attached to the upper end is converted into a rotation of the two front wheels 10, 11 as shown in FIGS. The front frame 2F can be swung rightward or leftward via the connecting pin 71 by converting the operation into a pushing / pulling operation of the connecting link 83 branched from the predetermined portion and connected to the rear frame 2R. I have to.

In FIG. 11, by turning the steering handle 3 clockwise, the connecting link 83 is pulled in, and the front frame 2F swings rightward about the connecting pin 71. Although the case is shown, the swinging direction of the front frame 2F is configured to be the same as the rotating direction of the two front wheels 10 and 11 as described above. That is, if the steering handle 3 is rotated in either direction, the connection link 8
The front frame 2F is swung by the push / pull operation of 3, and the two front wheels 10, 11 are also turned in the same direction.

[0005]

However, in the conventional steering device 81 as described above, since the front frame 2F of the in-field transport machine AO swings and swings, the minimum turning radius is small. There is a problem that the driver who operates the vehicle has a sense of incongruity because the driving sensation is different from that of a passenger car.

Further, the multiple link mechanism 82 and the connecting link 83 have a problem that it is difficult to reduce the cost because the structure is complicated and it is difficult to manufacture and attach the link to the front frame 2F or the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a field transportation machine having a small minimum turning radius can be operated with the same feeling as a passenger car, and has a simple structure and cost reduction. An object of the present invention is to provide a steering device for an internal transporter.

[0008]

Means for attaining the above object are as follows. First, a vertical axis vertically mounted on a body frame of a field transporter having a steering wheel and two front wheels is provided. A front axle whose center in the longitudinal direction is fixed so as to be horizontally rotatable around the axis of the vertical shaft, and a base portion which is rotatably fixed around the axis of the vertical shaft in conjunction with the front axle. A turning arm, and the front wheels are respectively erected on both ends of the front axle, and the front wheels are rotatably mounted around the axis.
Two support shafts, a motion conversion mechanism provided on the vehicle body frame to convert a rotation operation of the steering handle into an expansion / contraction operation, and a rotation shaft around one of the two support shafts. A telescopic operating part whose base is rotatably fixed in conjunction with the front wheel and performs telescopic operation of the motion conversion mechanism
A telescopic transmission arm having a distal end connected via a first relay link , a base fixed around the axis of the one support shaft so as to be rotatable in conjunction with the telescopic transmission arm and the front wheel; A second relay link at the tip of the turning arm
And a rotation transmitting arm having a distal end connected thereto, and a base fixed to each of the two support shafts so as to be rotatable in association with the front wheel and via a third relay link.
The vehicle has two front-wheel interlocking arms whose tip portions are connected to each other, and the turning direction of the front axle, the turning direction of the two front wheels, and the directions of these directions and the direction of rotation of the steering wheel are the same. It is configured to be.

Second, the motion conversion mechanism accommodates a handle shaft having the steering handle attached to the upper end and a pinion provided at the lower end , and a lower end of the handle shaft rotatably housed. tip and the housing, an elastic actuating part which the expansion and contraction by the rotation operation of and the pinion is accommodated in the pinion and meshed with the housing and is secured freely horizontally oscillating about the axis of the handle shaft to the vehicle frame lies in the arrangement in a steering gear box comprising a rack provided on.

Thirdly, the front axle, the vertical axis in the horizontal axis so that the axis direction is freely vertically swing about the axis of perpendicular horizontal axis to the longitudinal direction of the horizontal and front axle It has been attached to the shaft.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a steering device 1 according to this embodiment is provided on a vehicle body frame 2 of a transporter A in a field. The in-field transporter A includes, for example, a steering wheel 3 and two front wheels 10, 11 and a rear wheel 12,
The vehicle body frame 2 is formed integrally and is divided into a front section F and a rear section R as required. The steering device 1, the front wheels 10, 11 and the like are provided below the front section F, and the steering wheel 3, the driver's seat 14 and the like are provided above the front section F.

As shown in FIGS. 1 to 5, the steering device 1 comprises a vertical shaft 21, a front axle 22, and two support shafts 2.
3, 24, a swiveling arm 31, and a telescopic transmission arm 3
2, a turning transmission arm 33, two front wheel interlocking arms 34, 35, and a steering gear box (motion conversion mechanism) 40, and a turning direction of the front axle 22 and two front wheels 10, 11. The rotation direction, and these directions and the rotation direction of the steering handle 3 are configured to be the same direction.

The vertical shaft 21 is suspended from, for example, a central portion of the front section F of the body frame 2, and as shown in FIG.
The longitudinal center of the front axle 22 is fixed so as to be horizontally pivotable about the axis 21a of the vertical shaft 21.

The front axle 22, as shown in FIGS. 3 and 4, for example, is an inverted L-shape provided on the front side of the vertical shaft 21 so as to be rotatable around an axis 21a of the vertical shaft 21. And a bearing 26 fixed to the lower end of the fitting 25 as necessary and parallel to the projecting direction of the fitting 25 from the vertical shaft 21, and the bearing 26.
Between two mounting plates 28, which are fixed opposite to each other in a direction perpendicular to the axial direction of the horizontal shaft 27 and at predetermined intervals in the front-rear direction via a horizontal shaft 27 rotatably supported by It is stuck to. Therefore, the front axle 22 is horizontally rotatable around the axis 21a of the vertical shaft 21, and
It is vertically swingable around the axis 27a of the horizontal shaft 27. In this way, if the horizontal shaft 27 is interposed, the vertical swing (swing) operation of the front axle 22
Since the shaking of the vehicle body frame 2 due to the unevenness of the field while the transporter A in the field is running is absorbed, there is an advantage that the riding comfort is good.

As shown in FIGS. 2 and 4, the base 31a of the turning arm 31 is rotatably fixed around the axis 21a of the vertical shaft 21 via the attachment 25, for example. Therefore, the front axle 22 is connected to the turning arm 31.
When the turning arm 31 is turned, the front axle 22 turns horizontally.

As shown in FIG. 3, the support shafts 23 and 24 are erected at both ends of the front axle 22, for example, with their lower ends expanded outward and inclined. At the lower ends of the support shafts 23, 24, the front wheels 10, 11 are supported by the support shafts 2,
The shafts 3 and 24 are rotatably mounted around respective axes.

The steering gear box (motion conversion mechanism) 40 is disposed in, for example, the front section F of the body frame 2 and converts the rotation of the steering wheel 3 into a telescopic operation. As shown in FIGS. 6 to 8, the steering handle 3 is attached to the upper end side and
A handle shaft 42 having a pinion 41 provided at a lower end thereof, and a housing which rotatably accommodates the lower end of the handle shaft 42 and is fixed to the vehicle body frame 2 so as to be horizontally swingable around an axis 42 a of the handle shaft 42. 43 and the housing 4
3 to the pinion 41 and the telescopic hydraulic unit 4 to the expansion and contraction operation by rotation of the coupling to be housed and the pinion <br/> on 41
And a rack 45 provided at the tip .

The housing 43 is formed in a cylindrical shape, and as shown in FIGS. 6 and 7, the shaft center 42a of the handle shaft 42 is attached to the body frame 2 by using a known connecting mechanism (not shown).
It is fixed so that it can swing horizontally around it. As shown in FIG. 8, a lower end portion of a handle shaft 42 provided with the pinion 41 and the rack meshed with the pinion 41 are provided inside a bearing box 46 provided at an intermediate portion in a longitudinal direction of the housing 43. 45 are accommodated. In addition, the rack 45 is constantly pressed against the pinion 41 via the pressing body 48 by, for example, the elastic force of the coil spring 47 so that the meshing between them is ensured.

The pinion 41 is connected to the handle shaft 42
Are provided concentrically at the lower end of the. The rack 45 is
The distal end of the housing 43 is accommodated so as to protrude from an end 43a, and the telescopic operating portion 44 is provided at the distal end. Further, the telescopic operation part 44 and the housing 43
A bellows-shaped protection tube 49 is interposed between the end portion 43a and the end portion 43a as required.

In the steering gear box 40, the rotation of the steering handle 3 rotates the pinion 41 together with the handle shaft 42, and the expansion and contraction operation section 44 at the tip of the rack 45 meshed with the pinion 41 performs the expansion and contraction operation. It is supposed to. The extension operation of the telescopic operation unit 44 corresponds to the clockwise rotation operation of the steering handle 3, and the contraction operation of the telescopic operation unit 44 corresponds to the counterclockwise rotation operation of the steering handle 3. Thus, the motion conversion mechanism is connected to the steering gear box 4.
If it is set to 0, there is an advantage that the rotation operation of the steering wheel 3 can be reliably converted to the expansion and contraction operation of the expansion and contraction operation section 44 with less force.

As shown in FIGS. 2 and 3, the telescopic transmission arm 32 is provided at the upper end of, for example, the right one of the two support shafts 23, 24 at the upper end of the base 3 around its axis.
2a is rotatably fixed in conjunction with one of the front wheels 10,
Further, a tip portion 32b bent upward from the base portion 32a as necessary is connected to a telescopic operating portion 44 of the steering gear box 40 via a first relay link 51.

The turning transmission arm 33 has a base 33a rotatably fixed about the axis of one support shaft 23 in conjunction with the telescopic transmission arm 32 and the front wheel 10, and a tip 33b. Is connected to a distal end portion 31a of a turning arm 31 rotatably fixed to the vertical shaft 21 via a second relay link 52. In this embodiment, the turning transmission arm 33 and the telescopic transmission arm 3 are used.
2 are formed integrally, but the invention is not limited to this, and they may be formed separately if they are linked.

The front-wheel interlocking arms 34 and 35 have base portions 34 around the respective axes of the two support shafts 23 and 24.
a, 35a are rotatably fixed in conjunction with the front wheels 10, 11, respectively, and the tip portions 34b, 35b protruding inside the two front wheels 10, 11 respectively via a third relay link 53. Connected. The front wheel interlocking arms 34 and 35 are, for example,
The front wheel 1 is integrated with the
It is linked to 0,11. The one front wheel interlocking arm 34 fixed to the one support shaft 23 is
It is located almost directly below the telescopic transmission arm 32.

Next, the operation of the steering device 1 will be described with reference to FIGS. When the steering wheel 3 is not rotated in any direction, that is, as shown in FIG. 2, when the telescopic operation part 44 of the steering gear box 40 is in the neutral position, the front axle 22 is moved in the field A is parallel to the vehicle width direction of A, and the two front wheels 10, 11 are oriented in the front-rear direction.

In this state, in order to turn the transporter A in the field to the left, for example, as shown in FIG. 5, the front axle 22 and the two front wheels 10 and 11 are turned counterclockwise as shown in FIG. May be rotated counterclockwise. That is, due to the counterclockwise rotation of the steering handle 3, the telescopic operating portion 44 extends in the direction of the arrow a as described above.

For this reason, the first telescopic operating portion 44 has the first
The distal end portion 32b of the telescopic transmission arm 32 connected via the relay link 51 is pushed, and the one support shaft 23 is pressed.
The arm 33 for turning movement rotates counterclockwise by an angle D in conjunction with the arm 32 for expansion and contraction in conjunction with the arm 32 for telescopic transmission. Due to the turning operation of the turning transmission arm 33, the distal end portion 31b of the turning arm 31 connected via the second relay link 52 is pushed, and is turned counterclockwise around the axis 21a of the vertical shaft 21. While rotating, the front axle 22 also turns counterclockwise in conjunction with the turning arm 31.

The rotation of the telescopic transmission arm 32 and the rotation transmission arm 33 causes the front wheel 10 pivotally mounted on the one support shaft 23 to interlock with these operations.
The arm 34 rotates counterclockwise about the axis 3 by an angle D, and the one front wheel interlocking arm 34 also rotates counterclockwise by an angle D in conjunction with the front wheel 10. Therefore, the third relay link 53 is connected to the one front wheel interlocking arm 34.
And the other front wheel interlocking arm 35 is rotated counterclockwise about the axis of the other support shaft 24 by an angle D, and the other front wheel 11 is also connected to the other front wheel interlocking arm 35.
And rotates counterclockwise by an angle D.

That is, by the turning operation of the steering handle 3 in the counterclockwise direction, the extension operation of the expansion and contraction operation section 44 and the
The telescopic transmission arm 32, the turning transmission arm 33, the turning arm 31, the front axle 22, one front wheel 10, one front wheel interlocking arm 34, and the other front wheel interlocking arm 35,
And the counterclockwise turning operation of the other front wheel 11 is concurrently performed, so that the in-field transport machine A can be turned to the left.

Conversely, in order to turn the in-field transporter A clockwise, that is, to turn the front axle 22 and the two front wheels 10, 11 clockwise, the steering handle 3 may be rotated clockwise. .

[0030]

As described above, according to the first aspect of the present invention, since the front axle turns and the two front wheels also turn in the same direction, the minimum turning radius of the in-field transport machine is reduced. There is an advantage that it is easy to do. In addition, since the integrally formed frame can be used as the body frame, in this case, the swing motion does not occur as in the related art,
There is an advantage that the in-field transporter having a small minimum turning radius can be operated with the same feeling as a passenger car. Further, it is not necessary to use a multiple link mechanism or a connecting link having a complicated structure as in the related art, and the structure is relatively simple, so that the cost can be reduced.

According to the second aspect of the present invention, since the motion conversion mechanism is constituted by the steering gear box configured as described above, the rotation operation of the steering wheel can be reliably and more reliably performed by the expansion and contraction operation of the expansion and contraction operation section. There is an advantage that conversion can be performed with a small force.

According to the invention of claim 3, the front axle is
Since this horizontal axis is attached to the vertical axis so that the axis can be vertically swung about an axis of a horizontal axis which is horizontal and perpendicular to the longitudinal direction of the front axle, the transporter in the field The swing of the body frame due to the unevenness of the field during the traveling is absorbed by the vertical swing (swing) operation of the front axle, and therefore, there is an advantage that the riding comfort is good.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a steering device for an in-field transport machine according to an embodiment.

FIG. 2 is an enlarged schematic plan view of the steering device shown in FIG. 1;

FIG. 3 is a schematic front view of the steering device of FIG. 2 as viewed from the front.

FIG. 4 is an enlarged sectional view taken along line BB of FIG. 3;

FIG. 5 is an enlarged schematic plan view showing how the in-field transporter of FIG. 1 is turned to the left.

FIG. 6 is an enlarged plan view of the steering gear box.

FIG. 7 is a partially broken enlarged front view of the steering gear box.

FIG. 8 is an enlarged sectional view taken along line CC of FIG. 7;

FIG. 9 is a schematic plan view showing a conventional example.

FIG. 10 is a schematic side view showing the vicinity of a steering handle in a conventional example.

FIG. 11 is a schematic plan view showing a right turning state of the in-field transport machine of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS A In-field transport machine 1 Steering device 2 Body frame 3 Steering handle 10, 11 Front wheel 21 Vertical axis 21a Axis 22 Front axle 23, 24 Support shaft 27 Horizontal axis 27a Axis 31 Swing arm 31a Base 31b Tip 32 Expansion and contraction transmission Arm 32a base 32b tip 33 turning transmission arm 33a base 33b tip 34,35 front wheel interlocking arm 34a, 35a base 34b, 35b tip 40 steering gear box (motion conversion mechanism) 41 pinion 42 handle shaft 42a shaft center 43 Housing 44 Telescopic operation part 45 Rack 51 First relay link 52 Second relay link 53 Third relay link

Claims (3)

(57) [Claims] 1. A vertical shaft vertically suspended on a body frame of an in-field transporter having a steering wheel and two front wheels, and a substantially central portion in a longitudinal direction about an axis of the vertical shaft is fixed so as to be horizontally pivotable. and a front axle, a swivel arm which is rotatably fixed base about the axis of the vertical axis in conjunction with the front axle, the front the both ends in and around the axis are respectively erected axle two support shafts which a front wheel is freely wearing the axial rotation, a motion conversion mechanism for converting the rotational movement of the steering wheel is deployed on the body frame to stretch operation, one of the two support shafts is the base about the axis of one of the support shaft is rotatably fixed to in conjunction with the front wheel and front
The first relay is provided to the telescopic operation part that performs telescopic operation of the motion conversion mechanism.
A telescopic transmission arm having a distal end connected via a link; and a base fixed around the axis of the one support shaft so as to be rotatable in conjunction with the telescopic transmission arm and the front wheel, and turning.
Turning the transfer arm tip portion is communicated <br/> binding through the second relay link to the distal end of the use arms, times by the two support shafts base to respective axial center in conjunction with the front wheel Movably fixed to each other and a third relay ring
And two front-wheel interlocking arms whose tips are connected to each other via a hook, and the turning direction of the front axle, the turning direction of the two front wheels, and the directions of these and the turning direction of the steering handle are A steering device for a transporter in a field, wherein the steering devices are configured to be in the same direction. 2. The vehicle according to claim 1, wherein the motion conversion mechanism includes a steering shaft having the steering handle mounted on an upper end portion thereof and a pinion provided at a lower end portion, a lower end portion of the handle shaft rotatably housed, and a handle mounted on the body frame. from about the axis of the shaft and housing fixed freely horizontally oscillating, a rack provided with a telescopic actuating portion at the tip of the stretching operation by the rotation operation of and the pinion is accommodated in the pinion and meshing with said housing The steering apparatus for an in-field transport machine according to claim 1, wherein the steering gear box comprises a steering gear box. Axis wherein the front axle, the vertical axis in the horizontal axis so as to be freely vertically swing about the axis of perpendicular horizontal axis axially relative to the longitudinal direction of the horizontal and front axle The steering device for an in-field transport machine according to claim 1 or 2, wherein the steering device is worn.