JP2002037116A - Steering device for paddy field working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a structure. SOLUTION: A pitman arm 22 interlocked with a handle shaft 20 is swingingly supported to a steering bracket 21 rotatingly supporting the bottom end of the handle shaft 20, and respective left/right steering front wheels, left/right knuckle arms 23 integrally swinging with the left/right steering front wheels about a king pin shaft center, and the pitman arm 22 are interlocked and connected via a drag link 24 so that the left/right steering front wheels 5 are constituted to steer in the same direction with the rotation of the handle shaft 20. A regulation part 26 abutting on the pitman arm 22 and regulating the swinging range of the pitman arm 22 is integrally molded with the steering bracket 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a steering bracket for rotatably supporting a lower end portion of a handle shaft, a pitman arm interlocking with the handle shaft being swingably supported, and a left and right steering front wheel respectively. And the left and right knuckle arms that swing together around the kingpin axis and the pitman arm are linked and connected via a drag link,
The present invention relates to a steering device for a paddy field working machine such as a rice transplanter configured to steer the left and right steering front wheels in the same direction as the handle shaft rotates.

[0002]

2. Description of the Related Art In a steering apparatus for a paddy field working machine of this type, it is necessary to regulate the swing range of a pitman arm. Conventionally, in order to regulate the swing range of the pitman arm, a regulating member that contacts the pitman arm and regulates the swing range of the pitman arm has been screwed into the steering bracket.

Further, in the steering device of the paddy working machine, it is necessary to restrict the downward movement of the handle shaft with respect to the steering bracket. Conventionally, to restrict the downward movement of the handle shaft with respect to the steering bracket, a boss that is restricted from moving downward with respect to the steering bracket by contacting the steering bracket is attached to the handle shaft via a set bolt. I was

Further, conventionally, the pitman arm has been formed in a flat plate shape.

[0005] In addition, in the steering device of the paddy field working machine, it is necessary to allow the relative vertical movement of the pitman arm and the knuckle arm connected by the drag link. Conventionally, to allow relative vertical movement between the pitman arm and the knuckle arm, one end of the drag link is pivotally connected to the pitman arm via a ball joint, and the other end of the drag link is connected to the knuckle arm via a ball joint. Had a pivotal connection.

[0006] In this type of steering device for a paddy field working machine, a post insertion hole is formed in the top plate portion to cover the rear surface and left and right side surfaces of the handle post that rotatably supports the handle shaft and to insert the handle post upward. A post cover is provided. Conventionally, a post insertion hole through which the handle post is inserted from the upper end side is formed in the top plate of the post cover.

Conventionally, the post cover is bolted to a step in order to position the post cover in a horizontal plane.

Further, in the steering device of the paddy field working machine, the upper cover covering the entire periphery of the upper post portion of the handle post projecting above the top plate portion of the post cover, and the lower edge of the post insertion hole peripheral edge. It is common to attach it to the top plate by inserting it into the top plate. Conventionally, the top plate to which the upper cover is attached has been formed in a flat plate shape.

[0009]

However, the above-mentioned conventional technique has the following disadvantages. When the regulation member is screwed into the steering bracket to regulate the swing range of the pitman arm, the regulation member is a separate member from the steering bracket, and the number of constituent members is two. Is required, and the structure is complicated.

When the downward movement of the handle shaft with respect to the steering bracket is regulated by the boss mounted on the handle shaft with the set bolt, it can be surely regulated.
The structure became large-scale, leading to an increase in cost.

When the pitman arm is formed in a flat plate shape, if the pitman arm is provided at a high position, the drag link for linking the knuckle arm to the pitman arm is also arranged at a high position to prevent interference with a transmission case or the like. In order to make the linking performance by the drag link sufficient, the drag link must be thick, which results in an increase in weight and cost. .

When a ball joint is used to pivotally connect the drag link to each of the pitman arm and the knuckle arm, a total of four expensive ball joints are required on the left and right sides, resulting in an increase in cost.

In the case where the post insertion hole of the post cover allows the handle post to be inserted only from the upper end side, when the post cover is pulled upward, the steering handle mounted on the upper end of the handle shaft hits the top plate portion, Since the post cover cannot be detached, when the post cover is detached to open around the handle post and perform maintenance around the handle post, it is necessary to remove the steering handle from the handle shaft, resulting in poor workability.

When the post cover is bolted to the step, when the post cover is detached and maintenance around the handle post is performed, it takes time to detach the post cover, resulting in poor workability.

When the upper cover is attached to the flat top plate, if the post insertion hole is circular, the upper cover rotates around the post with respect to the top plate and easily comes off the top plate. .

In the paddy field working machine, when the steering wheel is turned more than a predetermined value in order to make a small turn, the steering clutch interposed in the transmission mechanism to the left and right driving rear wheels is disengaged. It is desired to be activated.

An object of the present invention is to solve the above-mentioned conventional disadvantages and satisfy the demand.

[0018]

The features, functions and effects of the steering apparatus for a paddy field working machine according to the present invention according to claim 1 are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported on a steering bracket rotatably supporting the lower end portion of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. In a steering device for a paddy field working machine, the steering bracket is integrally formed with a restricting portion that comes into contact with the pitman arm and restricts a swing range of the pitman arm.

[Operation] Since the steering bracket is integrally formed as a steering bracket with a restricting portion, the constituent member may be one of the steering brackets, and the mounting structure conventionally required is unnecessary.

[Effect] Therefore, the structure can be simplified.

The features, functions and effects of the steering apparatus for a paddy field working machine according to the second aspect of the present invention are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. A steering device for a paddy working machine is characterized in that two retaining rings are provided to restrict the downward movement of the handle shaft with respect to the steering bracket.

[Operation] The downward movement of the handle shaft is restricted by a simple and inexpensive retaining ring, and the restriction is restricted by two instead of one, so that the reliability of the restriction can be enhanced.

[Effect] Therefore, while the downward movement of the handle shaft with respect to the steering bracket is reliably restricted, the cost is rarely increased.

The features, functions and effects of the steering device for a paddy working machine according to the present invention according to claim 3 are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end portion of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. In a steering apparatus for a paddy field working machine, a pivot connection portion between the left and right drag links of the pitman arm is located below an interlocking portion with a handle shaft.

[Operation] While the interlocking portion with the handle shaft is positioned high to prevent the interlocking portion from interfering with the ground, the pivotal linking portion with the drag link is lowered, so that the drag link can be connected to a transmission case or the like. Since it can be installed at a low position where no interference occurs, it is not necessary to bend the drag link in a complicated manner in order to avoid interference with the transmission case, and the drag link can be thin while having sufficient linking performance.

[Effects] Therefore, reliable linking performance can be exhibited while reducing the weight and cost of the drag link.

The features, functions and effects of the steering device for a paddy working machine according to the present invention according to claim 4 are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. A steering device for a paddy working machine, wherein one of a pivotal connection means for the drag link to a pitman arm and a pivotal connection means for a drag link to a knuckle arm is formed of a ball joint, and the other is a ball joint. It consists of a pin joint.

[Operation] When the pitman arm and the knuckle arm are linked to each other by a drag link in a state in which the relative vertical movement of the pitman arm and the knuckle arm is allowed, the pivotal connecting means between the drag link and the pitman arm and the link between the drag link and the knuckle arm are provided. The inventor of the present invention has found that it is not necessary for both the pivotal connection means to be formed of a ball joint, and only one ball joint may be used. Based on this knowledge, only one pivot connection means is composed of a ball joint, and the other pivot connection means is composed of an inexpensive pin joint. I'm done.

[Effect] Accordingly, it is possible to reduce the cost while allowing the relative vertical movement of the knuckle arm and the pitman arm.

The features, functions and effects of the steering device for a paddy field working machine according to the fifth aspect of the present invention are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. A steering device for a paddy field working machine, wherein a post has a post insertion hole for covering a rear surface and left and right side surfaces of a handle post that rotatably supports the handle shaft and for inserting the handle post upward in a top plate portion thereof. Provide a cover, and on the top plate of this post cover,
Usually, a notch which is closed and reveals a gap allowing passage of the handle post by elastic deformation of the top plate portion on both sides thereof is formed in a state extending over the periphery of the post insertion hole and the periphery of the top plate portion. On the point.

[Operation] A notch is formed in the top plate to reveal a gap allowing the handle post to pass through, so that the middle portion of the handle post can be inserted into the post insertion hole from the side. When the post cover is detached, the handle post can be detached from the post insertion hole through the gap, and there is no need to remove the steering handle from the handle shaft.

[Effect] Accordingly, the post cover can be detached with good workability, and the maintenance property around the handle post can be improved.

The features, functions and effects of the steering device for a paddy field working machine according to the present invention according to claim 6 are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. A steering device for a paddy field working machine, wherein a post has a post insertion hole for covering a rear surface and left and right side surfaces of a handle post that rotatably supports the handle shaft and for inserting the handle post upward in a top plate portion thereof. A cover is provided, and the post cover is inserted into the positioning holes formed in the steps from above by inserting the post cover horizontally. Lies in that is integrally continuously provided a positioning protrusion to prevent movement of the inner.

[Operation] While the post cover is positioned in the horizontal plane by inserting the positioning projection into the positioning hole, the post cover can be detached from the step by pulling the positioning projection upward from the positioning hole. Therefore, the post cover can be detached with good workability.

[Effects] Therefore, the maintenance performance by detaching the post cover can be improved.

The features, functions and effects of the steering apparatus for a paddy field working machine according to the present invention according to claim 7 are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. A steering device for a paddy field working machine, wherein a post has a post insertion hole for covering a rear surface and left and right side surfaces of a handle post that rotatably supports the handle shaft and for inserting the handle post upward in a top plate portion thereof. A cover is provided to cover the entire periphery of the upper post portion of the handle post projecting above the top plate of the post cover. The part cover, plug attached to the top plate by to the periphery of the post insertion hole of its lower edge,
The present invention is characterized in that the periphery of the post insertion hole is curved in a side view.

[Operation] Since the periphery of the post insertion hole is curved in a side view, the upper cover does not rotate with respect to the top plate even if the post insertion hole is circular.

[Effect] Accordingly, it is possible to prevent the upper cover from rotating and detaching from the top plate.

The features, functions and effects of the steering apparatus for a paddy working machine according to the present invention according to claim 8 are as follows.

[Features] A pitman arm interlocking with the handle shaft is swingably supported by a steering bracket rotatably supporting the lower end of the handle shaft, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together with the pitman arm are linked to each other via a drag link, and the left and right steering front wheels are steered in the same direction with the rotation of the handle shaft. A steering device for a paddy working machine, wherein a front part of a frontal gate-shaped front wheel supporting case supporting a left and right steering front wheel in a state where the transmission mechanism for the left and right steering front wheel is installed is provided. The pitman arm is disposed in the pitman arm. The left and right interlocking rods are provided so that the steering clutch for the drive rear wheel inside the turning is reversibly disengaged and actuated in accordance with the steering swing more than the set angle from the front wheel support case. The steering clutch is disposed under the lateral case portion connecting the left and right, and in the middle of each of the interlocking rods, the steering swing of the pitman arm is elastically deformed at a second set angle or more that is larger than the set angle. Is provided with an operation difference absorbing spring which is not transmitted to the spring.

[Operation] When the pitman arm swings more than the set angle by rotating the steering handle more than the set angle, the steering clutch inside the turning clutch among the steering clutches interposed in the transmission mechanism to the left and right driving rear wheels. The pitman arm and the left and right steering clutches are interlocked via an interlocking rod to make a small turn so as to perform the disengagement operation, but the swing angle of the pitman arm required for disengaging the steering clutch is small. . Therefore, when the pitman arm and the steering clutch are simply interlocked, further swinging of the pitman arm after the steering clutch is disengaged is hindered by being interlocked with the steering clutch,
The steering front wheel cannot be steered to a large extent. Focusing on the above points, when the pitman arm swings over a second set angle that is larger than the set angle, it is elastically deformed and an operation difference absorbing spring that does not transmit the pitman arm swing to the steering clutch is provided. Therefore, the subsequent swinging of the pitman arm after the steering clutch is disengaged can be allowed by the elastic deformation of the operation difference absorbing spring.

[Effect] Therefore, the front steering wheel can be largely steered while the pitman arm and the steering clutch are interlocked, whereby the steering front wheel can be largely steered. This makes it possible to truly realize a small turn with good operability in synergy with automatically turning off the steering clutch inside the turn by the turning operation.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a rice transplanter, which is an example of a paddy field working machine, has a multi-row planting type, which is an example of a paddy field working device, at the rear of a riding type self-propelled machine 1. Of the seedling planting device 2 is connected via a four-link mechanism 3 so as to be able to move up and down, and the four-link mechanism 3 is raised and rocked with the supply of pressure oil, and the four-link mechanism 3 is seeded with the drainage. The self-propelled machine 1
And the four-link mechanism 3.

The self-propelled machine 1 has left and right driving front wheels 5 for driving, left and right driving rear wheels 6 and a step 7, and has a driving portion mounted on a front portion and a driver seat 8 mounted on a rear portion. ing.

As shown in FIG. 3, the prime mover is a hydrostatic continuously variable transmission that is switchable between forward and backward driven by the engine 9 and a main clutch 10 of a belt tension type. 11 and the continuously variable transmission 1
1 is provided with a transmission case 12 for transmitting the output of the vehicle 1 to the traveling section and the seedling planting apparatus 2. Mission case 1
2 is connected to a front portion of a main frame F having a structure in which a pair of left and right frame plates are connected at both front and rear ends, and an engine mounting frame f projecting forward is connected to the transmission case 12.

As shown in FIG. 5, the steering drive front wheel 5 is a lower end of a lower case portion 13A swingable about a king pin axis among left and right front axle cases 13 connected to the transmission case 12. Each is pivoted. In other words, the transmission case 12 and the left and right axle cases 13 form a front wheel support case 14 having a gate-shaped front view. The driving rear wheel 6 is connected to the main frame F
The left and right rear axle cases 16 connected to both ends of the left and right lateral transmission case 15 are pivotally supported. A transmission mechanism for driving the front steering wheel 5 is disposed in the front wheel support case 14, and a transmission mechanism is provided in the left and right lateral transmission case 15 and the rear axle case 16 from the transmission case 12 as shown in FIG. A transmission mechanism for transmitting the power transmitted via the shaft s to the driving rear wheel 6 is provided. As shown in detail in FIGS. 7 and 8, the steering clutch 17 is provided in the transmission mechanism for each of the driving rear wheels 6.
And the steering brake 18 are interposed in a state where the steering clutch 17 is located on the transmission upper side.

Step 7 includes a front step body 7F and a rear step body 7R. Front step body 7F
Has left and right getting on / off steps 7a and a bonnet 7b located on both left and right sides of the engine 9. The rear step body 7R includes a riding step 7c and left and right rear wheel fenders 7.
d.

A steering handle 19 is disposed in front of the driver's seat 8. As shown in FIGS.
The lower end of the handle shaft 20 equipped with
a, a steering bracket 21 rotatably supported by a is attached to a stay fs fixed to the engine mounting frame f via a bolt B.
First, a pitman arm 22 interlocking with the handle shaft 19 via a pinion gear pg and a sector gear sg is supported at a position forward of the front wheel support case 14 so as to be swingable about a vertical axis y. The pitman arm 22 and the knuckle arm 23, which swings integrally around the kingpin axis KP, and the pitman arm 22 are linked to each other via the drag link 24, thereby rotating the handle shaft 20. Accordingly, the left and right steering drive front wheels 5 are steered in the same direction. The knuckle arm 23 is connected to the lower case 13
It is bolted to A.

The steering bracket 21 is inserted into a curved elongated hole 25 formed around the vertical axis y formed in the pitman arm 22 and comes into contact with the end of the curved elongated hole 25 to swing the pitman arm 22. A protruding restricting portion 26 for restricting the movement range is integrally formed.

The means for restricting the downward movement of the handle shaft 20 with respect to the boss portion 21a of the steering bracket 21 is a means for providing two retaining rings 27 juxtaposed in the axial direction with the washer Wa interposed therebetween. Wb
Is a washer interposed between the upper surface of the pinion gear pg and the lower surface of the boss 21a.

Further, of the pitman arm 22, the pivotal connection portion 22a with the drag link 24 is located below the interlocking portion with the handle shaft 20, that is, below the sector gear forming portion 22b. The pivotal connecting means of the 24 to the pitman arm 22 comprises a pin joint 28, and the pivotal connecting means of the drag link 24 to the knuckle arm 23 comprises a ball joint 29. The pin of the pin joint 28 is configured by bending an end of the drag link 24.

As shown in FIGS. 10 to 12, on the rear and left and right side surfaces of the handle post 30 for rotatably supporting the handle shaft 20, a post insertion hole 31 for inserting the handle post 30 upward into the top plate portion is provided. It is covered with the formed post cover 32. The post cover 32 includes a positioning protrusion 34 for restricting the movement of the post cover 32 in a horizontal plane by being inserted into the positioning hole 33 formed in the step 7 from above, and a positioning hole formed in the bonnet portion 7b. A positioning protruding piece 36 for restricting the movement of the post cover 32 in the horizontal plane and the vertical movement of the post cover 32 by being inserted from the rear is formed integrally with 35. The top plate of the post cover 32 is normally closed and the handle post 3 is elastically deformed on both sides of the top plate.
A notch 37 that appears as a gap allowing the passage of zero is formed so as to extend over the periphery of the post insertion hole 31 and the periphery of the top plate.

The post cover 32 is provided with an upper cover 38 made of an elastic material and covering the entire periphery of the upper post portion of the handle post 30 projecting above the top plate. This upper cover 38 is attached to the post cover 32
Is a means for attaching the lower edge 38a of the upper cover 38 to the periphery 31a of the post insertion hole 31 by elastically inserting the lower edge 38a into the top plate portion. The periphery of the post insertion hole 31 is curved in a side view. are doing.

T is a fuel tank provided to cover the upper part of the engine 9.

As shown in FIG. 4, the operating means of the left and right steering clutches 17 and the steering brakes 18 are used to operate the inside of the turning when the steering handle 19 is steered more than a set amount from the straight traveling position. A means for disengaging the steering clutch 17 and braking the steering brake 18, specifically, reversibly disengaging the steering clutch 17 by swinging from a clutch engaged position to a clutch disengaged position. And a left and right shift arm 39 for reversibly braking the steering brake 18 in a state where the clutch 17 is maintained in the engaged state by swinging from the clutch disengagement position to the braking position. The left and right shift arms 39 are moved with respect to the drive rear wheel 6 on the inner side of the turn with the steering swing of the pitman arm 22 from the straight traveling posture. Left and right interlocking rods 40 are provided so as to cooperate with each other so that the lift arm 39 starts swinging reversibly from the clutch disengagement position. As shown in FIG. The pitman arm 22 does not transmit the swing of the pitman arm 22 to the shift arm 39 until the steering swing angle of the pitman arm reaches the set angle, and the steering swing of the pitman arm 22 is at least a second set angle larger than the set angle. Is provided by elastically deforming the operation difference absorbing spring 42 that does not transmit to the shift arm 39 on the inside of the turn, and the accommodation 43 that does not transmit the swing of the pitman arm 22 to the shift arm 39 for the driving rear wheel 6 on the outside of the turn. is there. That is, neither the steering clutch 17 nor the steering brake 18 is operated until the steering handle 19 is operated from the straight traveling position to the set amount or more.
When the steering handle 19 is operated beyond the set amount, first, the steering clutch 17 inside the turning is disengaged, then the steering brake 18 is braked, and the second brake after the steering brake 18 is braked is operated. The operation of the steering handle 19 beyond the set angle is allowed while maintaining the clutch disengagement / brake braking state. As shown in FIG. 5, the interlocking rod 40 is disposed below the front case portion 14 of the front wheel support case 14 that connects the left and right sides.

[Brief description of the drawings]

Fig. 1 Side view of rice transplanter

FIG. 2 is a plan view of a rice transplanter.

FIG. 3 is a cutaway side view of a driving unit.

FIG. 4 is an operation system diagram

FIG. 5 is a front view of a main part.

FIG. 6 is a cutaway side view of a main part.

FIG. 7 is a cutaway development view of a main part of the transmission mechanism in a clutch-on / non-braking state.

FIG. 8 is a cutaway development view of a main part of the transmission mechanism in a clutch disengaged / braking state.

FIG. 9 is a cutaway side view of a main part of an interlocking rod.

FIG. 10 is a perspective view of a main part with a post cover removed.

FIG. 11 is a cutaway side view of a main part.

FIG. 12 is a perspective view of a post cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Handle shaft 21 Steering bracket 22 Pitman arm 5 Steering front wheel 23 Knuckle arm 24 Drag link 26 Restriction part 27 Retaining ring 22a Pivot connection part 22b Interlocking part 29 Ball joint 28 Pin joint 30 Handle post 31 Post insertion hole 32 Post cover 37 Notch 35 Positioning Hole 36 Positioning Protrusion 14 Front Wheel Support Case 17 Steering Clutch 6 Drive Rear Wheel 40 Interlocking Rod 42 Spring for Absorbing Operation Difference

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B62D 7/12 B62D 7/12 7/18 7/18 Z 11/08 11/08 DX 49/49 / 00 F (72) Inventor Seiichi Takahashi 64 Ishizukita-cho, Sakai-shi, Osaka, Japan, inside Kubota Sakai Factory (72) Inventor Mikio Okuyama 64, Ishizukita-cho, Sakai-shi, Osaka Inside, Kubota Sakai Factory (72 ) Inventor Akihiro Sugioka 64, Ishizukita-cho, Sakai City, Osaka Prefecture, Japan (72) Inventor Kazuo Aoki 64, Ishizukitacho, Sakai City, Osaka Prefecture, in Kubota Sakai Factory, Inc. (72) Inventor Shusaku Fujimoto Osaka 64 Ishizu-Kitacho, Sakai-shi, Fukutome F-term in Kubota Sakai Works (reference) 2B043 AA04 AB02 AB03 AB08 AB13 BA02 BB06 DA03 DB02 2B062 AA02 AA14 AB01 BA11 BA22 BA41 CA18 3D030 DC03 3D034 BA00 BA03 BB04 B C01 BC03 BC14 BC22 BD03 3D052 AA02 BB08 DD03 EE03 FF01 FF02 GG03 HH01 JJ12 JJ19

Claims (8)

[Claims] A steering bracket rotatably supporting a lower end portion of a handle shaft has a pitman arm interlockingly linked with the handle shaft swingably supported, and is provided around each of the left and right steering front wheels and a kingpin axis. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy working machine, wherein the steering bracket is integrally formed with a restricting portion that comes into contact with the pitman arm and regulates a swing range of the pitman arm. 2. A steering bracket rotatably supporting a lower end portion of a handle shaft, wherein a pitman arm interlocking with the handle shaft is swingably supported, and each of the left and right steering front wheels and a kingpin axis center. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. What is claimed is: 1. A steering device for a paddy working machine, comprising two retaining rings for restricting downward movement of the handle shaft with respect to a steering bracket. 3. A steering bracket rotatably supporting a lower end portion of a handle shaft, a pitman arm interlocking with the handle shaft is swingably supported, and each of the left and right steering front wheels and a kingpin axis center. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy working machine, wherein a pivotal connection portion between the left and right drag links of the pitman arm is located below an interlocking portion with a handle shaft. 4. A steering bracket rotatably supporting a lower end portion of a handle shaft, wherein a pitman arm interlocking with the handle shaft is swingably supported, and each of the left and right steering front wheels and a kingpin axis center. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy field working machine, wherein one of a pivotal connection means for the drag link to a pitman arm and a pivotal connection means for a drag link to a knuckle arm is formed of a ball joint, and the other is a pin joint. Steering device of paddy working machine composed of joints. 5. A steering bracket for rotatably supporting a lower end portion of a handle shaft, wherein a pitman arm interlocking with the handle shaft is swingably supported. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy field working machine, comprising: a post cover that covers a rear surface and left and right side surfaces of a handle post that rotatably supports the handle shaft and has a post insertion hole formed in a top plate portion of the handle post to insert the handle post upward. Is provided on the top plate of the post cover, and the handle post is closed by elastic deformation of the top plate on both sides. A cutting device for a paddy field working machine, wherein a notch that reveals a gap that allows a gap is formed between the periphery of the post insertion hole and the periphery of the top plate. 6. A steering bracket rotatably supporting a lower end portion of a handle shaft, wherein a pitman arm interlocking with the handle shaft is swingably supported, and each of the left and right steering front wheels and the kingpin axis center. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy field working machine, comprising: a post cover that covers a rear surface and left and right side surfaces of a handle post that rotatably supports the handle shaft and has a post insertion hole formed in a top plate portion of the handle post to insert the handle post upward. The post cover is inserted into the positioning hole formed in the step from above by inserting the post cover in the horizontal plane. Steering device for paddy field working machine with integrated positioning protruding pieces that block movement. 7. A steering bracket for rotatably supporting a lower end portion of a handle shaft has a pitman arm interlockingly linked with the handle shaft rotatably supported, and is provided around each of left and right steering front wheels and a kingpin axis. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy field working machine, comprising: a post cover that covers a rear surface and left and right side surfaces of a handle post that rotatably supports the handle shaft and has a post insertion hole formed in a top plate portion of the handle post to insert the handle post upward. And an upper cover for covering the entire periphery of the upper post portion of the handle post projecting above the top plate of the post cover. And a lower edge of the post insertion hole is attached to the top plate by inserting the lower edge into the periphery of the post insertion hole, and the periphery of the post insertion hole is curved in a side view. 8. A steering bracket for rotatably supporting a lower end portion of a handle shaft, wherein a pitman arm interlocking with the handle shaft is swingably supported, and each of the left and right steering front wheels and the center of the kingpin axis. The left and right knuckle arms that swing together and the pitman arm are interlockingly connected via a drag link, and the left and right steering front wheels are steered in the same direction as the handle shaft rotates. A steering device for a paddy field working machine, wherein a transmission mechanism to the left and right steering front wheels is provided in a state in which the left and right steering front wheels are installed in front of a portal type front wheel support case that supports left and right steering front wheels. Arrange the pitman arm,
The pitman arm and the steering clutch interposed in the transmission system to each of the left and right driving rear wheels are steered with respect to the driving rear wheel inside the turning with the steering swing from the straight posture of the pitman arm beyond the set angle. Providing left and right interlocking rods for interlocking so that the clutch is reversibly operated, these interlocking rods are arranged under the horizontal case portion connecting the left and right of the front wheel support case, and in the middle of each of the interlocking rods, A steering apparatus for a paddy field working machine, comprising a spring for absorbing an operation difference that elastically deforms a steering swing greater than a second set angle greater than the set angle of the pitman arm and does not transmit the swing to a steering clutch.