JP2003304702A - Walking type plower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution of lifting up and down mechanism for lifting up a rotary plowing device without lifting up a handle, and also aim at the improvement of various operating properties by reviewing the total constitution of a walking type plower accompanying with the adoption of the lifting up and down mechanism. <P>SOLUTION: This walking type rotary plower by arranging a transmission case 3 and traveling wheels 12, 12 at the center of a machine body and the rotary plowing device 4 and an operating handle 22 at one side of the front and rear of the transmission case 3, and constituting the rotary plowing device 4 as capable of being lifted up and down is constituted by arranging a hitch part 13 and a lifting up and down actuator (a hydraulic cylinder 66) for joining the rotary plowing device 4 at the rear part of the transmission case 3 as freely being lifted up and down and supporting a tail wheel-supporting body 47 against the rotary plowing device 4 as capable of freely sliding up and down by joining the operating handle 22 and the upper part of the tail-supporting body 47 to the lifting up and down actuator through a lifting up and down linking mechanism 40. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a walk-type cultivator and a lifting mechanism for a working machine.

[0002]

2. Description of the Related Art In a walk-type cultivator equipped with a working machine such as a rotary cultivator, when the vehicle is traveling or turning, the working machine is lifted to move away from the field, and the work of moving the machine is performed quickly. At times, the working machine is lowered to perform plowing work in the field. Conventionally, when raising or lowering the working machine, a tail wheel provided at a rear portion of the working machine is artificially operated up or down, or simply by lifting or lowering an operation handle.

[0003]

However, the vertical operation of the tail wheel requires the operation of rotating the screw rod or the operation of lowering the tail wheel support rod and the like, and at the time of traveling at the end of the field, the working machine on the handle side. It requires a great deal of effort to lift, is a cumbersome operation, and is a work burden.

Further, by lifting the operating handle, the traveling wheels serve as fulcrums, and the working machine is seen in a side view.
Although it will rise diagonally rearward, at this time, for example, the tilling claws of the rotary tiller are exposed, and there is a risk that the field will be damaged. Of course, it can be said that there is a risk of involuntarily injuring the field not only when traveling but also when traveling. Further, at this time, if the tail wheel rotates due to its own weight and swings to the front side, the distance between the tail wheel and the plowing claw becomes short, and there is a risk that the two interfere with each other. Further, the tail wheel sometimes interferes with the ridger by swinging to the left or right when changing the direction during traveling, and the maneuverability during traveling was not good.

In view of the above problems, the present invention provides a structure of an elevating mechanism for elevating a rotary tiller without lifting a handle, and with the adoption of the elevating mechanism, the entire structure of a walk-type tiller is improved. By reviewing it, we propose a walk-behind cultivator with improved operability.

[0006]

The problems to be solved by the present invention are as described above, and the means for solving the problems will be described below.

That is, as described in claim 1, the mission case and the traveling wheels are arranged in the center of the machine body, and the rotary tiller and the operation handle are arranged on one side of the front and rear of the mission case so that the rotary tiller can be moved up and down. In the walk-type cultivator configured, a hitch part for vertically connecting the rotary cultivator to the mission case and an elevating actuator are arranged, and the operation handle and the upper part of the tail wheel support are connected to the elevating actuator through the elevating link mechanism. The tail wheel support is connected to the rotary tiller so as to be slidable up and down.

According to a second aspect of the present invention, in the elevating and lowering link mechanism, the lower part of the suspension link pivotally connected to the handle base is pivotally connected to a front position in the front-rear halfway portion of the swing link,
The front part of the swing link is pivotally connected to the rotary drive case, while the rear part supports the upper part of the tail wheel support.

Further, according to a third aspect of the present invention, the tail wheel is arranged below a ridger attached to a rear portion of the rotary cultivator in a maximum lowered state with the rotary cultivator being raised. Is Rukoto.

Further, according to a fourth aspect of the present invention, an arm support portion is provided below the tail wheel support body, and an fulcrum shaft having an axis centering in a direction perpendicular to the axis center of the tail wheel support body is arranged. A tail wheel arm is rotatably supported on the shaft, and the tail wheel is rotatably supported at the lower end of the tail wheel arm, and the caster amount of the tail wheel arm is large when the tail wheel is in forward contact when it is in contact with the ground. It is designed to be small when floating in the air.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an overall side view of a walk-type cultivator, FIG. 2 is a transmission path diagram, FIG. 3 is a cross-sectional plan view of a chain case, FIG. 4 is a diagram showing a configuration of a hitch when a rotary cultivator is raised, and FIG. 5 is a rotary cultivator. FIG. 6 is a diagram showing the structure of the hitch when descending, FIG. 6 is a rear view showing the structure of the hitch, FIG. 7 is a plan view of the same, FIG. 8 is a partial plan view showing the structure of a walk-type cultivator, and FIG. 9 is a handle structure. The top view shown, FIG. 10 is a partial side view showing a state of the walk-type cultivator at the time of traveling and traveling, FIG. 11 is a partial side view showing a state of the walk-type cultivator at the time of cultivating, and FIG. 12 is a rotary. FIG. 14 is a diagram showing the positional relationship between the ridger and the tail wheel when the tiller is raised, and FIG. 13 is a diagram showing the positional relationship between the ridger and the tail wheel when the rotary tiller is lowered. FIG. 4 is a partial side sectional view showing a configuration of an arm support portion.

First, the overall construction of a walk-type cultivator 30, which is an embodiment equipped with a rotary cultivator 4, will be described with reference to FIGS. 1 and 2. The walk-type cultivator 30 has an engine 2 in the front, a rotary cultivator 4 as a working machine in the rear, and a mission case 3 in the center, and the engine 2 is mounted and fixed on an engine stand 5 (FIG. 1). The rear part of the engine base 5 is fixed to the mission case 3. Pulleys 6a and 7a (Fig. 2) are fixedly mounted on the output shaft 6 of the engine 2 and the input shaft 7 of the transmission case 3, respectively, so that power is transmitted via a transmission belt. A belt tension type main clutch 10 (FIG. 2) is arranged between the output shaft 6 and the input shaft 7, and these are covered by a transmission case 9.

The rotational power input from the input shaft 7 into the mission case 3 is adjusted in speed by a transmission, and the axle 11 is axially supported in the mission case 3 below the mission case 3. And the traveling wheels 12 are fixedly mounted on the axle 11 so that the vehicle can be driven to travel.

A hitch portion 13 is provided at the rear portion of the mission case 3, and the front portion of the rotary tiller 4 is connected to the hitch portion 13. Further, on one side (right side) of the mission case 3, a front chain case 26a and a rear chain case 26b, which are formed in a refraction type in a front-rear direction, are arranged, and the front chain case 26a (FIG. 2) is provided with PTO shaft 15 protruding laterally from the mission case 3
To allow the power to be transmitted into the chain case 26a. Also, at the rear of the rear chain case 26b,
The rotary input shaft 27 is pivotally supported, and the rotary input shaft 27 and the tillage pawl shaft 16 are wound by a chain in the rotary drive case 14 so that power is transmitted to the tillage pawl shaft 16. . A plurality of tilling claws 17, 17 ... Are planted on the shaft of the tilling claw shaft 16.
The upper and lateral sides of the turning locus of the tips of 17 ... Are covered with a tillage case 31 (FIG. 1) fixedly mounted on the rotary drive case 14. This tillage case 31 projects the upper part of the rotary drive case 14 toward the upper part of the case from the inner cavity part of the lower part of the case in the front part of the substantially left-right center in a plan view, and covers substantially the entire range in the front-back direction of the upper surface of the case. The beam 18 formed so as to project upward is fixed to the rear portion of the rotary drive case 14 so that the entire case is firmly fixed to the rotary drive case 14. Tiller 4
It is designed to go up and down as it goes up and down.

As shown in FIG. 3, the front chain case 2 is provided.
6a and the rear chain case 26b are the front chain case 26a.
The rear part and the front part of the rear chain case 26b are rotatably connected. And the front chain case 26
At the front part of a, the sprocket 52 fitted to the end of the PTO shaft 15 is rotatably supported, and the rear chain case 26b
A sprocket 55 fitted to the rotary input shaft 27 is rotatably supported at the rear portion. In addition, a connecting portion 26e between the front chain case 26a and the rear chain case 26b
A connecting shaft 58 connects the front chain case 26a and the rear chain case 26b in the left-right direction, and the connecting shaft 58 is rotatably supported by the front chain case 26a and the rear chain case 26b, respectively.

As shown in FIG. 3, a sprocket 53 is fitted in the front chain case 26a of the connecting shaft 58, and a sprocket 54 is fitted in the rear chain case 26b of the connecting shaft 58. The sprocket 54 is rotatably supported by the rear chain case 26b. The transmission chain 56 is wound between the sprocket 52 at the end of the PTO shaft 15 and the sprocket 53 fitted to the connecting shaft 58 in the front chain case 26a. Similarly, in the rear chain case 26b, the sprocket 54 fitted to the connecting shaft 58 and the sprocket 5 at the end of the rotary input shaft 27 are arranged.
A transmission chain 57 is fitted between the five. Therefore, the PTO
The connecting shaft 58 is interposed between the shaft 15 and the rotary input shaft 27 so that the front and rear chain cases 26a and 26b are connected to each other by the connecting portion 26e.
Even if it is bent at, the transmission chain 56
The rotation drive of the PTO shaft 15 is transmitted to the rotary input shaft 27 via the connecting shaft 58 by 57. And
The rotary input shaft 27 has a sprocket fitted to the end opposite to the end inserted into the chain case, and is input to the rotary drive case 14.

As described above, by making the front chain case 26a and the rear chain case 26b of the refraction type, the rotary tiller 4 moves up and down and the position of the rotary input shaft 27 with respect to the PTO shaft 15 will be described later. Changes and both axes (15
Even if there is a change between the centers of the sprockets 52 and 55 fitted in (27), the front and rear and center portions of the chain case 26 are bent so that they can be dealt with.

Next, the connecting portion between the rotary tiller 4 which is a working machine and the machine body 1 will be described. As shown in FIG. 1, the rotary tiller 4 is connected to the rear portion of the body 1 by a hitch portion 13 provided on the rear surface of the mission case 3. As shown in FIG. 4, the hitch portion 13 is configured such that a hitch 13b on the rotary tiller 4 side can be vertically moved up and down with respect to a hitch 13a on the mission case 3 side. As shown in FIGS. 4 to 8, the hitch 13a on the side of the mission case 3 includes a pair of left and right brackets 61a and 61b (FIG. 7) mounted rearward on the right side of the side of the mission case 3 and the brackets 61a and 61b. It is composed of a pair of left and right rails 63a and 63b fixed to the rear end and extending in the vertical direction. Here, the brackets 61a and 61b are formed by a plate body having a substantially "L" shape in a plan view, and the front inner surface of the bracket is fixed to the mission case 3 while being fixed between the brackets 61a and 61b. A space for sandwiching the hydraulic cylinder 66 is formed, and substantially the rear end of the hydraulic cylinder 66 is bent in the left-right direction from the front-back direction. In this way, the hitch 13a is in a state where its position is fixed to the machine body 1 via the mission case 3 (FIG. 4).

On the other hand, the hitch 13 on the rotary tiller 4 side
b (FIG. 4) is composed of brackets 64a and 64b fixed to the rotary drive case 14 and a sliding body 65 which is a connecting portion of the hitch 13a fixed to the brackets 64a and 64b with fixing bolts 35a and 35b. Has been done. The sliding body 65 is fixed to the brackets 64a and 64b by a fixing bolt 3
A pair of left and right plates 65 fixed by 5a and 35b
e.65e (FIG. 7), an upper pivot 28a and a lower pivot 28b (FIG. 4) that laterally bridge the plates 65e, 65e at two upper and lower points, and rotatable shafts at the left and right axial ends of both pivots 28a, 28b, respectively. It is composed of supported rollers 65a and 65b. In the sliding body 65 thus configured, the rollers 65a and 65b are inserted between the rails 63a and 63b provided on the hitch portion 13 of the machine body 1, and the rollers 65a and 63b are inserted.
It is movable up and down by the rotation of 65a. A substantially central portion of the upper pivot 28a is clamped by a grip portion 59 of the elevating arm 32, which is substantially U-shaped in side view.

The lifting arm 32 (FIG. 4) is rotatably connected to the pivot 60 on the opposite side of the grip portion 59, and in the middle part, the rod 67 of the hydraulic cylinder 66, which is a lifting actuator. The rod 71 is pivotally connected by a joint 71 and a pivot 79 provided at the tip of the rod 67.
By the expansion and contraction of the lifting arm 32, the raising and lowering arm 32 is swung so that the grip 59 is moved in the vertical direction with the pivot 60 as the fulcrum. The hydraulic cylinder 66 is supplied and discharged with pressure oil by a hydraulic pump 72 (shown in the approximate center of FIG. 1) provided above the cylinder.

Further, as shown in FIG. 7, the rail 63 is
a. 63b has a substantially "U" shape in a plan view, and as shown in FIG. 4, a bolt hole is formed in the upper side surface so that the bolt 76 is laid horizontally to close the upper opening. Thus, the upward movement range of the roller 65a, that is, the upward movement range of the sliding body 65 is regulated. On the other hand, the lower portions of the rails 63a and 63b are left open without opening the bolts, that is, the bolts are not laid horizontally, and the moving range of the lower rollers 65b is not restricted by the rails 63a and 63b. When the rod 67 of the hydraulic cylinder 66 shown in FIG. 5 is in the most contracted state, the lowering of the upper pivot 28a is regulated by regulating the clockwise rotation of the lifting arm 32 by the rod 67. is there. In this way, hitch 13a
The lower ends of the rails 63a and 63b are open so that the dirt and dust floating around the hitch portion 13 do not accumulate on the lower portions of the rails 63a and 63b, and the rollers 65a and 65b rotate. The movement is carried out favorably, and the rotary tiller 4 is constantly moved up and down smoothly.

Further, as shown in FIGS. 4, 7 and 8,
Hitch 13a and rotary tiller 4 on the body side
The side hitch 13b is arranged in the left and right center of the machine body, and the left and right brackets 61a and 61b forming the machine body side hitch 13a accommodate a hydraulic cylinder 66 as a lift actuator. With such a configuration, the hydraulic cylinder 66 is housed in the hitch 13a, and the hitch portion 13 (hitch 13a.
3b) The overall fit is good, the periphery of the hitch portion 13 is not complicated, and since these are arranged in the left and right center of the machine body, they do not interfere with the width adjustment of the traveling wheels 12, 12. Also, the hydraulic cylinder 66 is attached to the bracket 61.
Since it is hidden by a.61b, the appearance is not unsightly.

Further, as shown in FIGS. 1 and 9, the elevating switch 23 for operating the hydraulic cylinder 66 is a switch formed on the horizontal rod 21 which horizontally extends the rear portions of the left and right handle rods 22a and 22b. By providing the stay 29 with the switch stay 29 arranged in the lateral center of the horizontal rod 21, the elevating switch 23 is arranged in the lateral center of the operation handle 22. As a result, the operator can easily access the elevating switch 23 with either the left or right hand while holding the gripping portions 22c and 22d formed on the rear portions of the handle rods 22a and 22b. The sexuality is being improved. Further, the elevating switch 23 switches the switch "O" every time it is pressed.
The push switch is set to "N" or "OFF", and the operation can be performed instantaneously, and the operability is improved.

Further, as shown in FIG. 4, the rail 63 is provided with a pin hole 77, and the plate 65e of the sliding member 65 is also provided with a pin hole 78.
7 and 78, when the sliding body 65 has moved to the lowest point, that is, as shown in FIG. Then, in this state, the locking pin 80
By inserting the rails 63a and 63b,
The sliding body 65 is fixed, that is, the rotary cultivator 4 is fixed to the machine body 1. in this way,
Since the hitch portion 13, which is the connecting portion, is provided with the fixing means for fixing the sliding body 65 fixedly mounted on the rotary tiller 4 side, for example, when the hydraulic pump 72 is out of order, the rotary tiller 4 is a machine body. It becomes possible to fix it to the main body 1 side, and the work can be performed without rocking (vibrating) the rotary tiller 4 in the vertical direction.

Further, as shown in FIG. 1, the upper end of the hydraulic pump 72 is positioned so as to be positioned on the extension line of the line of the upper surface of the transmission case 9 in the right side view of the machine body so as to have a front low rear height. By arranging it at an angle, the appearance is improved. The angle of this inclination is within a range that does not hinder the operation of the hydraulic pump 72.

Further, as shown in FIGS. 4 and 5, a limit switch 37 is arranged at a position above the rail 63a, and when the contact detecting portion 38 of the limit switch 37 comes into contact with the roller 65a, The controller (not shown) detects the uppermost state of the sliding body 65 and the rotary drive case 1
4 (rotary tilling device 4) can be recognized to be in an ascending state. By detecting the lifted state of the rotary drive case 14 by the limit switch 37, for example,
When the rising state of the rotary drive case 14 is detected when the key switch for turning the engine “ON” and “OFF” is set to “ON”, the hydraulic pump 72 (not shown in FIG. 1) is required to maintain this rising state. (Shown in the central portion) is operated to keep the rod 67 in an extended state, and it is possible to perform control so as not to lower the rotary tiller 4 immediately after the key switch is turned on.

Further, as shown in FIG. 6, a gas spring 62, which is an assist device, is arranged on the side of the rail 63 arranged on the right side in the rear view of the machine body, and the end portion of the rod 62a of the gas spring 62 is It is connected to the right end of the upper pivot 28a protruding from the rail 63. The gas spring 62 is configured to urge the upward pivot shaft 28a in the upward direction, that is, in the direction in which the rod 62 is extended to reduce the burden of the lifting operation of the rotary tiller 4 by the hydraulic cylinder 66 and to reduce the load of the rotary tiller. The lifting and lowering operations of 4 are performed smoothly. In addition to the gas spring 62, an electric actuator, a spring, or the like can be used as the assist device.

In the walk-type cultivator 30 according to the present invention, the rails 63a.6 for guiding the up and down movement of the hitch portion 13 are provided.
Since 3b is provided in a substantially vertical direction, the sliding member 6
5 slides on the rails 63a and 63b substantially vertically. That is, the rotary tiller 4 (rotary tiller 4) moves up and down in a substantially vertical direction without changing its posture. In this way, when the rotary tiller 4 moves up and down substantially vertically,
The angle of the rotary tiller 4 does not change, and therefore, the change in angle between the tiller case 31 and the tiller claws 17, 17 ... Is small and stable tilling performance can be exhibited. Plow claws 17, 17 ...
Is not exposed to the operator side.

When a mudguard sheet (not shown) is provided at the rear of the tilling case 31 to prevent the soil from jumping up, even if the rotary tiller 4 is raised, the rotary tiller 4 is parallel. As a result, the lower end of the mudguard sheet rises a little as compared with when the rotary tiller 4 is in the position for plowing work, but the position relatively close to the ground is maintained. Therefore, in the conventional cultivator of the type in which the operation handle 22 is lifted at the time of traveling to raise the rotary cultivating device 4, if the worker forgets to disengage the work clutch and moves backward, the soil will be lifted up to the operator side. If it is a type that raises in parallel with, even if you forget to disengage the work clutch, the rear is not opened, so
The soil that has been lifted up will hit the mudguard sheet and will not be caught by the operator.

Next, the lifting link mechanism will be described.
As shown in FIG. 8, FIG. 10 and FIG. 11, the rotary tiller 4 is configured such that the lifting / lowering link mechanism 40 moves up and down with respect to the machine body 1, and the lifting / lowering link mechanism 40 is mounted on the handle base 81. The lower part (pivot 85) of the hanging link 84 that is pivotally connected is pivotally connected to a front position in the front-rear halfway part of the swing link 41, and the front part of the swing link 41 is pivotally connected to the rotary drive case 14 (pivot 86 In addition, the rear part supports the upper part of the tail wheel support 47.

The structure of the lifting link mechanism 40 will be described in detail below. Handle base 81 fixed to the machine body 1
As shown in FIG. 10, a stay 82 is projectingly provided, and a pivot 83 (FIG. 8) is laterally provided in the stay 82 in the left-right direction, and an upper portion of a suspension link 84 (FIG. 10) is pivotally connected to the pivot 83. Is
The suspension link 84 is swingably and pivotally connected to the machine body 1. This suspension link 84
The front and rear suspension links 84a and 84b provide the pivot 83
, And both suspension links 84a and 84b are connected by a fixing bolt 33 so as to be rotatably suspended on a pivot 83. The suspension link 84 (suspension link 84b) is pivotally connected to the swing link 41 and a pivot 85 at its lower portion. The swing link 4
As shown in FIG. 8, the rotary drive case 1 is pivotally connected to the rotary drive case 14 by a pivot shaft 86 projecting to the left outside on a line coaxial with the rotary input shaft 27.
4 is moved up and down to move the swing shaft 41.
Oscillates around a pivot 85, which is a pivotal connection point with the suspension link 84. The pivot 85, which is the pivot point, is arranged at a front position in the front-rear halfway portion of the swing link 41, and when the swing link 41 is a "lever" with the pivot 85 as a fulcrum, the pivot becomes an action point. The distance between 86 and the pivot 85, which is a fulcrum, is shortened so that the rear portion (so-called load point) of the swing link 41 is largely moved up and down with respect to a small up and down movement of the pivot 86.

Further, the attachment structure of the tail wheel 46 is as follows in order to support the raising and lowering of the rotary tiller 4. As shown in FIGS. 12 and 13, a sliding support cylinder 94 is formed at the rear portion of the beam 18, and the tail wheel support cylinder 4 of the tail wheel support 47 is attached to the sliding support cylinder 94.
By inserting 7c slidably, the rotary tiller 4
The vertical movement of the fixed support cylinder 92 is guided by the tail wheel support cylinder 47c by moving up and down.

A supporting portion 87 is formed at the rear end of the swing link 41. The structure of the support portion 87 is such that the plate-shaped stay 87a is pivotally supported at the rear end of the swinging link 41 via one link 87b, and the stay 87a has an opening through which the tail wheel support cylinder 47c is inserted. Form and swing link 41
The stay 87a is moved by the swinging (elevating) of the tail wheel support cylinder 4
It is designed to move in the vertical direction as guided by 7c. The opening of the stay 87a is smaller than the connecting case 90 formed in the upper portion of the tail wheel support cylinder 47c, and the upper surface of the stay 87a is in contact with the lower surface of the connecting case 90. The operation shaft 89 of the lifting handle 88 is projected rearward from the connecting case 90, and the screw rod 47 in the tail wheel support cylinder 47c is transmitted by the transmission of a bevel gear.
b of the tail wheel support cylinder 4 and the screw rod 47b.
The tail wheel support rod 47a, which is slidably inserted in the vertical direction 7c, is screwed into a female screw formed on the inner surface of the tail wheel support rod 47a, and the vertical position of the tail wheel 46 can be freely changed by operating the elevating handle 88. Further, the stay 87a is formed as a plate, and the lower surface of the stay 87a is in contact with the upper surface of the sliding support cylinder 94. As a result, when the rotary tiller 4 is raised to the uppermost position (state shown in FIG. 12), the sliding support cylinder 94
Moves to the uppermost position, and in the process of moving to the uppermost position, abuts on the lower surface of the stay 87a and pushes up the stay 87a so that the upper surface of the stay 87a abuts on the lower portion of the connection case 90. Tail wheel support cylinder 4 by sliding support cylinder 94 (beam 18) via the stay 87a
7c is to be supported. With the above configuration, when the rotary tiller 4 is raised, the tail wheel support cylinder 47c is stretched by the upper surface of the stay 87a so as to hold the lower surface of the stay 87a, so that the tail wheel 46 and the traveling wheel 12 are retained.
The walking cultivator 30 is supported by 12 so that the walking cultivator 30 is in a traveling or traveling state.

The lifting and lowering of the rotary tiller 4 by the lifting and lowering link mechanism 40 will be described below. First, the process of raising the rotary tiller 4 will be described. Figure 1
0 and FIG. 12, when the rod 67 of the hydraulic cylinder 66 is extended by operating the elevating switch 23 (FIG. 1), the elevating arm 32 raises the rotary drive case 14 via the sliding body 65, Along with the plowing claw 17
················· and the tillage case 31 fixed to the rotary drive case 14 rises. As the rotary drive case 14 rises, the pivot 86 projecting from the case rises, and the front end of the swing link 41 rises.
Due to the rise of the front end of the swing link 41, the pivot 85 also rises, and the suspension link 84 raises the handle base 81. When the handle base 81 is raised,
By rotating the handle base 81 about the pivot 83, the angle of the operation handle 22 is changed so that the state in which the operation handle 22 is held can be maintained. Furthermore, the rear part of the swing link 41 is lifted by the rise of both pivots 85 and 86, the stay 87a provided at the rear part abuts against the connecting case 90, and the swing link 41 supports the connecting case 90. . In this way, when traveling,
The walking cultivator 30 as a whole has running wheels 12 and a tail wheel 46.
Is supported by the rotary cultivator 4 and the rotary cultivator 4 is largely floated from the field, and the clearance between the cultivating claws 17, 17 ... and the field is increased, and the vehicle can be run or circulated. Will be in a state where it can be easily performed.

Next, the process of lowering the rotary tiller 4 will be described. As shown in FIGS. 11 and 13,
When the rod 67 of the hydraulic cylinder 66 is contracted by operating the elevating switch 23 (FIG. 1), the elevating arm 32 lowers the rotary drive case 14 via the sliding body 65, and accordingly, the tillage claws 17, 17. .., and the tillage case 31 fixed to the rotary drive case 14 descends. By lowering the cultivating case 31, the supporting state of the connecting case 90 by the beam 18 is released. As the rotary drive case 14 descends, the pivot 86 protruding from the case descends, and the swinging link 41 rotates about the pivot 85 of the suspension link 84 so as to lower the front end. To be made. And hydraulic cylinder 6
When 6 is completely contracted, the rotary tilling device 4 lands the tilling claws 17, 17 ..., and becomes the tilled state.

Further, the arrangement of the elevating link mechanism 40 described above is as follows. That is, as shown in FIG. 8, the mission case 3 and the traveling wheels 12, 12 are arranged in the center of the machine body, the rotary tiller 4 and the operation handle 22 are arranged on one side of the front and rear of the mission case 3, and the rotary tiller 4 is installed. In a walk-type cultivator configured to be able to move up and down, a rotary cultivator 4 is provided at the rear of the mission case 3.
And a hydraulic cylinder 66 as a lift actuator are arranged, and the operation handle 2 is connected to the hydraulic cylinder 66 via a lift link mechanism 40.
2 and the tail wheel 46 (FIG. 10) are connected to each other, and front and rear chain cases 26a and 26b which are transmission mechanisms from the mission case 3 to the rotary tiller 4 and the lifting link mechanism 4 are connected.
Since 0 is arranged on the opposite side of the front and rear center of the machine, the weight balance in the left and right direction of the machine is good, and when cultivating, traveling, traveling, and over ridges. The body balance can be easily maintained by grasping the operation handle 22.

Next, the positional relationship of the tail wheel 46 with respect to the ridger 91 will be described. As shown in FIGS. 12 and 13, in the beam 18 of the cultivating case 31, a fixed support cylinder 92 whose upper and lower sides are opened is formed in front of the sliding support cylinder 94, and the fixed shaft 93 is slid on the fixed support cylinder 92. A ridger 91 is provided which is freely movably inserted so that the vertical height can be freely adjusted by fixing the bolts.
The ridges can be formed after plowing.

The ridger 91 is moved up and down by the vertical movement of the beam 18 due to the elevation of the rotary tiller 4, and the state shown in FIG. 12, that is, the rotary tiller 4 is raised and the lift handle 88 is moved. Tail wheel 4 by operating
6 is lowered to the lowest position, the ridger 91
The tail wheel 46 is arranged downward with respect to. Thus, the tail wheel 46 is the rotary tiller 4
Of the tail wheel support cylinder 47c is supported by the rotary cultivator 4 side (beam 18), and the tail wheel 46 is at the lowest position, the rear cultivator 4 has a rear portion. It is arranged below the mounted ridger 91. Therefore, in the traveling or traveling state, even when the tail wheel 46 swings to the left or right, it does not hit the ridge 91, the direction can be easily changed, and the maneuverability of the aircraft is improved. .

Next, the support structure of the tail wheel 46 will be described. As shown in FIG. 14, at the lowermost portion of the tail wheel support rod 47a, the standing surfaces 19a and 19b and the compatible mounting surfaces 19a and 19b are provided.
A "gate" -shaped arm support portion 19 is constituted by a horizontal surface 19c that horizontally extends over the upper part of b, and the standing surface 19 of the arm support portion 19 is formed.
A fulcrum shaft 19d is laterally provided on the a and 19b, and the upper part of the tail wheel arm 20 is pivotally connected to the fulcrum shaft 19d.
By pivotally connecting the tail wheel axle 46a to the lower portion,
(FIG. 13) is configured to be hung from the tail wheel support rod 47a via the arm support portion 19 and the tail wheel arm 20. Further, the tail wheel arm 20 includes a pair of left and right arm portions 20a.2.
0b and the connecting portion 20c that connects the upper ends of both arm portions 20a and 20b, each portion is formed into a plate body to form a substantially "gate" shape in rear view, and the tail wheel 46 is formed at the opening of the "gate". It is designed so that it can pass through the upper half. The upper surface of the connecting portion 20c, which is the uppermost portion of the tail wheel arm 20, has
In the right side view of the machine body shown in FIG. 4, a bent portion 20f is formed in front of (or behind) a vertical line passing through the axial center of the fulcrum shaft 19d so as to have a substantially "V" shape, and the arm portion 20a is formed.
When the 20b rotates, the front end 20d or the rear end 20e of the connecting portion 20c comes into contact with the lower surface of the horizontal surface 19c. Then, in the side view in FIG. 14, since the distance between the bent portion 20f and the rear end 20e becomes long, the rear end 20
The rotation angle until e comes into contact with the lower surface of the horizontal surface 19c can be increased, and the caster amount of the tail wheel arm 20 (the inclination of the tail wheel arm 20 in the side view shown in FIG. 14) becomes large (position 24a). ). On the other hand, since the distance between the bent portion 20f and the front end 20d becomes short, the front end 20d is located at the horizontal plane 19
The rotation angle until it comes into contact with the lower surface of c is small, and the caster amount of the tail wheel arm 20 is small (position 24).
b). In addition, it is not the connecting portion 20c but the arm portions 20a.
The upper part of 0b may be formed in a substantially "V" shape.

The above construction, that is, the tail wheel support rod 47a
In the lower part, the arm support portion 19 in which a fulcrum shaft 19d having an axis in a direction perpendicular to the axis of the tail wheel support rod 47a is arranged,
The tail wheel arm 20 is rotatably supported by the fulcrum shaft 19d, the tail wheel 46 is rotatably supported at the lower end of the tail wheel arm 20, and the uppermost portion of the tail wheel arm 20 is formed into a substantially "" shape. The caster amount of the tail wheel arm 20 can be reduced by forming it in a mold and bringing the uppermost portion into contact with the inner surface of the arm supporting portion 19.
When the tail wheel touches down, it is large when moving forward and small when floating in the air. As a result, when the tail wheel touches the ground, the tail wheel 46 is arranged rearward with the forward movement of the airframe, the tail wheel arm 20 is at the position 24a, and the rear end 20e of the connecting portion 20c is the lower surface of the horizontal surface 19c. When the tail wheel arm 20 is rotated to the maximum angle, the caster amount becomes large. By increasing the caster amount at the time of touchdown, the tail wheel 46 can follow the direction in a good direction, and the straightness of the airframe can be improved. On the other hand, when the tail wheel 46 floats in the air, the tail wheel arm 20 rotates in the direction in which the tail wheel axle 46a is lowered by the weight of the tail wheel 46, and the front end 20d abuts the lower surface of the horizontal plane 19c. The rotation stops at the position 24b. Also, in this state, the tail wheel support rod 4
When 7a is rotated, tail wheel arm 20 is at position 24c. As described above, when the tail wheel 46 is suspended in the air, the front-rear position of the tail wheel arm 20 is the position 24b or the position 24c, and the caster amount is smaller than that of the position 24a. Thus, by reducing the caster amount when floating in the air, the tail wheel 46 rotates, and even in the state of the front side position 24c, the tilling claws 17, 17 ... In the tilling case 31 are ... It is possible to maintain the large distance between the tail wheel 46 and the tiller 17
・ It is possible to prevent interference with 17 ...

Next, the mounting structure of the rotary tiller 4 will be described. As described above, the rotary drive case 14
The front brackets 64a and 64b are fixed to the sliding body 65 by fixing bolts 35a and 35b,
By releasing the fixing by the fixing bolts 35a and 35b, the connection with the sliding body 65 is released, and the rotary drive case 14 and the transmission case 3 via the hitch portion 13 are released.
The connection with will be released. Further, the suspension link 84 sandwiches the pivot 83 by two front and rear suspension links 84a and 84b, and both suspension links 84a and 84b.
A single link is formed by screwing together the fixing bolt 33 with the fixing bolt 33, which is rotatably suspended on the pivot 83. The fixing bolt 33 is removed to remove both links 84a and 84a.
By releasing the connection of b, both links 84a, 84
b is divided into front and rear, and the connection between the swing link 41 and the handle base 81 via the suspension link 84 is released. Further, the PTO shaft 15 is disengaged from the sprocket 52 as shown in FIG.
The connection between the front and rear chain cases 26a and 26b and the mission case 3 via the 5 will be released. By disconnecting the above three points, the front and rear chain cases 26a and 26b on the rotary tiller 4 side, the rotary drive case 14,
Mission case 3 and handle base 8 on the body 1 side
1 is released and the rotary tiller 4 is attached to the body 1
Can be easily removed from.

As described above, in the walk-type cultivator equipped with the rotary cultivator, the mission case 3 and the handle base 81 are connected to the body main body 1 side, the rotary drive case 14, the front chain case 26a, and the lifting link mechanism 40. The rocking link 41 is used as a connecting portion on the side of the rotary tiller 4,
The rotary tiller 4 is connected to the machine body 1 by connecting both connecting parts. The connecting structure of the connecting parts is such that the rotary drive case 14 and the mission case 3 are connected and suspended via the hitch part 13. The swing link 41 and the handle base 81 are connected via the link 84, and the front chain case 26a and the mission case 3 are connected via the PTO shaft 15 to easily release the connection to the machine body 1. It is possible.

[0043]

Since the present invention is constructed as described above, it has the following effects. That is, as described in claim 1, a walk in which the mission case and the traveling wheels are arranged in the center of the machine body, the rotary tiller and the operation handle are arranged at one side in front of and behind the mission case, and the rotary tiller is configured to be able to move up and down. In a type cultivator, a hitch part and an elevating actuator for connecting the rotary cultivating device to the up and down freely are arranged at the rear of the mission case, and the operation handle and the upper part of the tail wheel support are connected to the elevating actuator via an elevating link mechanism, Since the tail wheel support is configured to be slidable up and down with respect to the rotary cultivator, the rotary cultivator can be raised without raising the operation handle, and the work efficiency is improved. You can The tail wheel and the rotary tiller easily move in the opposite directions, and the rotary tiller can be easily moved up and down.

According to a second aspect of the present invention, in the lifting / lowering link mechanism, the lower part of the suspension link pivotally connected to the handle base is pivotally connected to the front position of the middle part of the swing link.
Since the front part of the swing link is pivotally connected to the rotary drive case and the rear part supports the upper part of the tail wheel support, the entire walking type cultivator is supported by the traveling wheel and the tail wheel, and the rotary cultivator is supported. The device is in a state of being largely floated from the field, and the clearance between the tilling claw and the field is increased, so that the device can be run or circulated, and the ridge can be easily crossed.

According to a third aspect of the present invention, the tail wheel is arranged below the ridger mounted on the rear part of the rotary tiller in the maximum lowered state with the rotary tiller raised. Therefore, in the traveling or traveling state, even if the tail wheel swings to the left or right, it does not hit the ridge, the direction can be easily changed, and the maneuverability of the aircraft can be improved.

Further, according to a fourth aspect of the present invention, an arm support portion is provided below the tail wheel support body, in which a fulcrum shaft having a shaft center in a direction perpendicular to the shaft center of the tail wheel support body is arranged, and the fulcrum is provided. A tail wheel arm is rotatably supported on the shaft, and the tail wheel is rotatably supported at the lower end of the tail wheel arm, and the caster amount of the tail wheel arm is large when the tail wheel is in forward contact when it is in contact with the ground. Since it is configured to be small when floating in the air, the amount of casters at the time of ground contact becomes large, and the tail wheel direction followability becomes good,
The straightness of the airframe can be improved. Also, when the tail wheel floats in the air, the amount of casters is small, and it is possible to maintain a large distance from the tilling claw inside the tilling case, and it is possible to prevent interference between the tail wheel and the tilling claw. Can be prevented.

[Brief description of drawings]

FIG. 1 is an overall side view of a walk-behind cultivator.

FIG. 2 is a transmission path diagram.

FIG. 3 is a cross-sectional plan view of a chain case.

FIG. 4 is a view showing a configuration of a hitch when the rotary tiller is elevated.

FIG. 5 is a view showing the structure of a hitch when the rotary tiller is lowered.

FIG. 6 is a rear view showing the structure of the hitch.

FIG. 7 is a plan view of the same.

FIG. 8 is a partial plan view showing the configuration of a walk-behind cultivator.

FIG. 9 is a plan view showing a handle structure.

FIG. 10 is a partial side view showing a state of the walk-type cultivator during traveling and traveling.

FIG. 11 is a partial side view showing a state of the walk-type cultivator at the time of tilling.

FIG. 12 is a diagram showing a positional relationship between the ridge and the tail wheel when the rotary tiller is raised.

FIG. 13 is a diagram showing a positional relationship between the ridge and the tail wheel when the rotary tiller is lowered.

FIG. 14 is a partial side sectional view showing the structure of an arm support portion.

[Explanation of symbols]

3 mission case 4 Rotary tiller 12 running wheels 13 Hitch part 22 Operation handle 40 Lifting link mechanism 46 tail wheel 47 Tail wheel support

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2B033 AA06 AB01 AB11 AC04 BA20                       CA32 CA34 DA05 ED06 ED14                 2B304 KA08 LA01 LA06 LB05 LB13                       QC04 QC16 RA11

Claims (4)

[Claims] 1. A walk-type cultivator in which a mission case and traveling wheels are arranged in the center of the machine body, a rotary cultivator and an operation handle are arranged on one side of the front and rear of the mission case, and the rotary cultivator can be moved up and down. At the rear of the mission case, a hitch part for vertically connecting the rotary tiller and an elevating actuator are arranged, and the operating handle and the upper part of the tail wheel support are connected to the elevating actuator via an elevating link mechanism, and the tail wheel support is connected. A walk-type cultivator characterized in that it is configured to support a rotary cultivator in a vertically slidable manner. 2. The lifting / lowering link mechanism pivotally connects a lower portion of a suspension link pivotally connected to a handle base to a front position in the middle of the front and rear of the swing link, and the front portion of the swing link is a rotary drive case. The walk-type cultivator according to claim 1, wherein the rear part supports the upper part of the tail wheel support while being pivotally connected to the rear part. 3. The tail wheel is arranged below a ridger attached to a rear portion of the rotary tiller when the rotary tiller is in a maximum lowered state in a raised state. The walk-type cultivator according to claim 1 or 2. 4. An arm support portion is provided below the tail wheel support body, wherein a fulcrum shaft having an axis perpendicular to the axis of the tail wheel support is arranged, and the tail wheel arm is rotated on the fulcrum axis. The tail wheel arm is rotatably supported at the lower end of the tail wheel arm, and the caster amount of the tail wheel arm is set to a large value when the tail wheel is moving forward when the tail wheel is in contact with the ground and a small value when floating in the air. The walk-type cultivator according to claim 3, characterized in that