JPH084411B2 - Walk-type paddy work machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vertical drive structure of wheels and a balance structure of the entire body of a walk-type paddy working machine such as a direct-seeding paddy or a walk-type rice transplanter.

[Prior Art] A walk-behind rice transplanter, which is one of walk-behind paddy work machines, has a structure in which wheels running on a tiller are vertically driven to maintain a constant height from the rice field to the body. As a vertical drive structure for this wheel, a transmission case is extended rearward from the mission case at the front of the machine body, and a wheel is provided at the extended end of the transmission case to swing the transmission case up and down around the connection point with the mission case. There is one that is driven dynamically.

The walk-behind rice transplanter is equipped with a seedling planting device composed of a seedling stand and a planting arm in the rear part, and many seedlings are placed on the seedling stand during planting work, and the rear part of the machine becomes heavy and Is in a backward descending state, and the reverse torque from the wheels when moving forward further causes the aircraft to descend backward, so in order to prevent such a backward descending state as much as possible, as described above. Wheels are provided at the extending ends of the rearward facing transmission cases, and the wheels are arranged so as to approach the rear side of the machine body.

In the above-mentioned configuration, when the transmission case is rocked downward, the wheels move downward, and at the same time, they move forward of the machine body.
The effect of preventing the backward tendency as described above will be weakened.
Therefore, for example, as disclosed in Japanese Utility Model Publication No. 62-28810, on the front side of the transmission case supporting the wheels,
The hydraulic cylinder is arranged in the frame that supports the engine, and the forward movement of the piston rod in the hydraulic cylinder is converted into the downward movement by the bell crank, and the transmission case is rocked downward. There are things that are doing.

As a result, the piston rod and the linkage system from the piston rod to the transmission case move forward with the downward swing operation of the transmission case. It is possible to prevent the tendency to descend afterward due to moving to.

[Problems to be Solved by the Invention]

In the above-mentioned Japanese Utility Model Publication No. 62-28810, a bell crank for converting the longitudinal movement of the piston rod into the vertical movement is arranged above the transmission case of the wheel.

As a result, when a space for allowing the bell crank to swing up and down is secured in the upper part of the transmission case, when an attempt is made to equip the upper part of the machine (upper side of the bell crank) with a seedling stand, etc.
The position of the preliminary seedling stand will inevitably be high, which will hinder the forward standing view of the pilot standing on the rear side of the aircraft and the center of gravity of the aircraft will become high.

The present invention is a walking type paddy working machine equipped with a vertical drive structure for a wheel that suppresses the backward descending tendency of the machine body, so that an upper structure such as a preliminary seedling stand does not hinder the forward visibility of the operator. The purpose is to make the entire vertical drive structure simple.

[Means for solving the problem]

The feature of the present invention resides in that the above walking type paddy working machine is configured as follows.

A pair of left and right transmission cases, which are vertically swingably supported around the first horizontal axis of the mission case at the front of the machine body, extend rearward of the machine body, are provided with wheels at their extending ends, and have a frame extending from the transmission case forward of the machine body. And the engine is mounted on this frame, and the first hydraulic cylinder is arranged in the frame so that its piston rod projects toward the front of the machine body. The tip of the piston rod of the first hydraulic cylinder and the first horizontal axis A pair of left and right second balance arms that can swing back and forth are provided around a second horizontal axis between and, and both ends of the first balance arm swingably supported around the vertical axis of the tip of the piston rod. The left and right second balance arms are connected to each other by a rod, and the first case in the transmission case is connected.
An arm fixed upward on the horizontal axis and the second left and right
The upper part of the balance arm is connected by a rod, and the double-acting second hydraulic cylinder is connected over the piston rod of the first hydraulic cylinder and the lower part of one of the second balance arms.

[Work]

(I) When configured as in the present invention, for example, as shown in FIGS. 1 and 2, when the piston rod (6a) of the first hydraulic cylinder (6) is operated to project toward the front of the machine body, this operation causes left and right movements. The arm (5a) of the transmission case (5) supporting the wheels (4) is pushed to the rear side of the fuselage by being converted to the movement toward the rear of the fuselage by the second balance arm (9), and the transmission case (5)
Is oscillated downward. In this way, the projecting movement of the piston rod (6a) of the first hydraulic cylinder (6) toward the front of the machine body is not changed to the up-and-down movement in the middle thereof but is kept in the forward-backward movement by the second balance arm (9). It is transmitted to the transmission case (5), and the transmission case (5) is rocked downward.

As described above, in the present invention, the second balance arm is provided between the tip of the piston rod (6a) at the tip of the first hydraulic cylinder (6) and the first horizontal axis (P ₁ ) of the transmission case (5). Since (9) is arranged, even if an upper structure such as a spare seedling stand is mounted on the upper part of the transmission case (5), the position of the upper structure is lowered regardless of the second balance arm (9). Can be set.

(Ii) For example, as shown in FIG. 2, the arm (5a) connected to the second balance arm (9) is fixed upward to the portion of the first horizontal axis (P ₁ ) of the transmission case (5). Therefore, when the predetermined vertical movement range of the wheel (4) is obtained by the ratio of the length of the transmission case (5) and the length of the arm (5a), the length of the second balance arm (9) and the front-rear direction are set. It is not necessary to set the swing range to a particularly large one.

Then, between the tip of the piston rod of the first hydraulic cylinder (6) and the horizontal axis (P ₁ ) of the transmission case (5), the second
Since the balance arm (9) is arranged and the arm (5a) is provided at the portion of the first horizontal axis (P ₁ ) closest to the first hydraulic cylinder (6), the side of the first hydraulic cylinder (6) is The rod (10) connecting the first balance arm (7) and the second balance arm (9) and the rod (11) connecting the second balance arm (9) and the arm (5a) are set to short ones. can do.

(Iii) In the present invention, for example, as shown in FIGS. 1 and 2, the double-acting second hydraulic cylinder (8) is provided with the piston rod (6a) of the first hydraulic cylinder (6) and the second hydraulic cylinder (6a). It is connected to the bottom of the balance arm (9). As a result, when the second hydraulic cylinder (8) is extended, for example, one second balance arm (9) swings counterclockwise in FIG. 2 and one transmission case (5) swings upward. The first balance arm (7) is oscillated by the rod (10) counterclockwise in FIG. 1 by the rod (10), and the other transmission case (5) is oscillated downward. In this way, the left and right transmission cases (5) can be oscillated in a contradictory manner by the expansion and contraction operation of the second hydraulic cylinder (8), and the lateral attitude of the machine body can be changed.

In this case, the second hydraulic cylinder (6) as well as the second hydraulic cylinder (6)
Since the hydraulic cylinder (8) is located below the front part of the machine body, the second hydraulic cylinder (8) contributes to the tendency of the machine body to descend backward and to lower the center of gravity of the machine body.

Since (iv) is arranged, when the force to lift the wheels and the transmission case upward is generated, especially, when a shock is generated, the bell crank should be swung on the part that swingably supports it. At the same time as the moment to try, a force to lift the bell crank as a whole acts.

On the other hand, in the present invention, since the second balance arm is arranged not between the top of the transmission case but between the tip of the piston rod of the first hydraulic cylinder and the first horizontal axis of the transmission case, the wheels and the transmission are If the force to lift the case upwards is particularly shocking, only the moment that tries to swing the second balance arm acts on the portion that supports the second balance arm so that it can swing. Therefore, the force to lift the second balance arm as a whole does not act.

〔The invention's effect〕

As described above, by arranging the second balance arm between the tip of the piston rod of the first hydraulic cylinder and the first horizontal axis of the transmission case, a spare seedling stand or the like placed on the upper portion of the transmission case can be provided. Since the position of the upper structure can be set low, it is possible to improve the forward visibility for the operator standing on the rear side of the aircraft and improve the maneuverability of the walk-type paddy work machine. did it.

The hydraulic cylinder is arranged in the frame that supports the engine, and the above-mentioned upper structure is retained while maintaining the advantage of the conventional structure in which the transmission case is rocked downward by the projecting movement of the piston rod toward the front of the machine body. Can be set lower, and the second hydraulic cylinder that changes the attitude of the machine in the left-right direction is located below the front part of the machine, so that the backward tendency of the machine can be further suppressed and the center of gravity of the machine can be further lowered. As a result, the running stability of the walk-behind paddy work machine could be improved.

Since it is not necessary to set the length and the swinging range of the second balance arm to be particularly large, and the rod that connects the respective parts can be set to be short, the entire vertical drive structure of the wheel is simple and compact. It was possible to reduce the weight of the walk-behind paddy work machine.

Then, only a moment for swinging the second balance arm acts on the portion that swingably supports the second balance arm, and a force for lifting the second balance arm as a whole acts. Therefore, the structure is advantageous in terms of strength.

〔Example〕

A walk-behind rice transplanter, which is one of the embodiments of the present invention, will be described below with reference to the drawings.

As shown in FIG. 4, a frame (2) extends forward of the fuselage from a mission case (1) arranged in the left and right center on the front side of the fuselage, and an engine (3) is mounted on the frame (2). A pair of left and right transmission cases (5) having wheels (4) are extended from the transmission case (1) to the rear of the machine body, and are the first fulcrum which is the front end fulcrum of the transmission case (5).
A transmission case (5) is supported so as to be vertically swingable around a horizontal axis (P ₁ ). A seedling planting device including a planting arm (24) and a seedling stand (25) is provided at the rear of the machine body.

As shown in FIGS. 1 and 2, a single-acting first hydraulic cylinder (6) has a piston rod (6a) in the front of the machine body in a frame (2) located on the front side of the machine body with respect to the transmission case (5). The piston rod (6
The second balance arm (7) is swingably supported around the vertical axis (P ₂ ) at the front end of a). First hydraulic cylinder (6)
Of the tip of the piston rod (6a), between the first horizontal axis of the transmission case (1) (P _1), the second horizontal axis (P ₃₎ around the left and right sides of the frame (2), A pair of left and right second balance arms (9) swingable back and forth is provided, and a rod (10) is provided between the left and right ends of the first balance arm (7) and the lower parts of the left and right second balance arms (9). It is connected. The upward arm (5a) is fixed to the first horizontal axis (P ₁ ) part of the left and right transmission cases (5), and is fixed to the left and right arms (5a) and the upper parts of the left and right second balance arms (9). A crossing rod (11) is connected.

With the above structure, when the piston rod (6a) of the first hydraulic cylinder (6) is extended so as to project toward the front of the machine body, the left and right transmission cases (5) are rocked downward, and conversely. When the piston rod (6a) of the first hydraulic cylinder (6) is contracted, the left and right transmission cases (5) are rocked upward.

As shown in FIGS. 1 and 2, the downward arm (13) is fixed to the boss portion (12) fixed to the left second balance arm (9), and the first hydraulic cylinder (6) is fixed. A bracket (14) is fixed to the tip of the piston rod (6a), and a double-acting second hydraulic cylinder (8) is connected between the bracket (14) and the arm (13).

With the above structure, when the second hydraulic cylinder (8) is extended, for example, the second balance arm (9) on the left side in FIG. 2 swings counterclockwise on the paper surface, and the left transmission case (5) moves. It is rocked upwards, and the rod (10) moves the first
The balance arm (7) is swung counterclockwise in FIG. 1, and the right transmission case (5) is swung downward. In this way, the left and right transmission cases (5) can be oscillated in a reciprocal manner by the expansion and contraction operation of the second hydraulic cylinder (8).

The expansion / contraction operation of the first hydraulic cylinder (6) and the second hydraulic cylinder (8) as described above is performed based on the operation of the center float (15). As shown in FIG. 4, the center float (15) has a rear portion swingably supported around the third horizontal axis (P ₄ ) and the front-rear axis (P ₅ ). The vertical movement of the front part of the is detected mechanically, and the operation of supplying / discharging the hydraulic oil to / from the first hydraulic cylinder (6) is performed. This allows the center float (1
The expansion / contraction operation of the first hydraulic cylinder (6) is performed so that the position of 5) becomes the set position, that is, the height from the rice field to the machine body becomes the set height.

As shown in FIG. 3, the swing motion of the center float (15) around the front-rear axis (P ₅ ) is caused by the center float (15).
It is transmitted to the operation part (18a) of the control valve (18) for the first hydraulic cylinder (6) via the operation arm (16) and the bell crank (17) at the front part of the. As a result, the second hydraulic cylinder (8) is expanded and contracted to keep the machine body parallel to the rice field regardless of the unevenness of the tiller.

In this case, it is possible to temporarily fix the anti-oscillation operation of the wheels (4) of the left and right transmission cases (5).
As shown in FIG. 3, the arm (19) swingable around the shaft center (P ₆ ) and the operating portion (18a) of the control valve (18) are interlockingly connected via a linkage rod (20). Arms and arms (19)
It is movable up and down around the shaft center (P ₇ ) at the other end of the control lever (2) and is held in two upper and lower positions by the ball detent (21).
2) is installed. As a result, the control valve (18) is neutrally stopped by operating the operation lever (22) upward and engaging it in the central recess (23a) of the lever guide (23) as shown in FIG. It is fixed in position.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of the walking paddy working machine according to the present invention,
Fig. 1 is a plan view of the mission case and the vicinity of the first and second hydraulic cylinders, Fig. 2 is a side view of the mission case, the vicinity of the first and second hydraulic cylinders, and Fig. 3 is the center float and the second hydraulic cylinders. FIG. 4 is a perspective view showing the structure of cooperation with the control valve of FIG. 4, and FIG. 4 is an overall side view of the walk-behind rice transplanter. (1) ... mission case, (2) ... frame,
(3) ... Engine, (4) ... Wheels, (5) ... Transmission case, (5a) ... Transmission case arm, (6) ... First hydraulic cylinder, (6a) ... First hydraulic pressure Cylinder piston rod, (7) ... first balance arm, (8) ... second
Hydraulic cylinder, (9) ... Second balance arm, (10),
(11) …… Rod, (P ₁ ) …… First horizontal axis core, (P ₂ ) ……
Vertical axis, (P ₃ ) ... Second horizontal axis.

Claims (1)

[Claims] 1. A first of a mission case (1) at the front of an airframe.
A pair of left and right transmission cases (5) supported to be swingable up and down around a horizontal axis (P ₁ ) are extended to the rear of the machine body, and wheels (4) are provided at the extended ends, and the transmission case (1) is provided. Extend the frame (2) to the front of the machine from this frame (2)
The engine (3) is mounted on the first hydraulic cylinder (6), and the first hydraulic cylinder (6) is arranged in the frame (2) such that its piston rod (6a) projects toward the front of the machine body. Piston rod (6
A pair of left and right second balance arms (9) swingable back and forth are provided around a second horizontal axis (P ₃ ) between the tip of a) and the first horizontal axis (P ₁ ), Both ends of the first balance arm (7), which is swingably supported around the longitudinal axis (P ₂ ) of the tip of the piston rod (6a), and the lower parts of the left and right second balance arms (9), (1
0), the arm (5a) fixed upward to the portion of the first horizontal axis (P ₁ ) of the transmission case (5) and the upper portions of the left and right second balance arms (9). ,
A piston rod (6a) of the first hydraulic cylinder (6) connected by a rod (11)
And a double-acting second hydraulic cylinder (8) connected to the lower part of the one second balance arm (9).