JP2009060847A - Implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an implement capable of freely setting operation force required when changing posture of an extending and leveling part, to some extent, when energizing the extending and leveling part in the direction rotating from a retreating posture to an extending posture in whole area of rotating range of the extending and leveling part capable of changing the posture to an extending posture and retreating posture by carrying out rotation. <P>SOLUTION: In the implement, a tensile spring 41 in which one end side is hooked on an extending and leveling part 26 and other end side is hooked on one end side of a link 46 is provided and a regulating part 50 for regulating rotation of the link 46 on this side in which a hooking part 45 on other end side of the tensile spring 41 extends to dead point is provided when rotatably supporting the other end side of the link 46 around a shaft center parallel to a rotation shaft center X of the extending and leveling part 26 on the side of a main leveling part 25 so that spring force of the tensile spring 41 act on a direction rotating the extending and leveling part 26 from a retreating posture to the extending posture in the extending posture and rotating the extending and leveling part 26 from the extending posture to the retreating posture. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a working machine having a leveling function such as a rotary tiller or a plowing harrow.

Conventionally, there is a rotary cultivator as a working machine having a leveling function, and the rotary cultivator is mounted on a rear part of a tractor through a three-point link mechanism so as to be movable up and down, and in a horizontal direction at a lower part of the machine frame. A rotary tiller part in which a number of tillage claws are attached to a claw shaft provided so as to be rotatable around the axis of the shaft, and a tillage cover that covers the rotary tiller part.
The tillage cover includes a main cover that covers the upper side of the rotary tillage part and a rear cover that covers the rear of the rotary tillage part, and a leveling part that grounds the field and grounds the field is provided on the lower end side of the rear cover. ing.

As the leveling part, a main leveling part formed in a left and right length corresponding to the left and right width of the main part of the rear cover, and provided on both left and right sides of the main leveling part, outward from the main leveling part in the left-right direction. There is an extended leveling portion that is extended, and the extended leveling portion is rotatably supported by the main leveling portion, and by rotating, outward from the main leveling portion in the left-right direction. The posture can be changed between an extended posture that extends and a retracted posture that is located above the main leveling portion.
In addition, while plowing the extended leveling part in the extended posture, even if the extended leveling part is pushed up by the pressing force from the soil and rotated to the retracted position side, it can reliably return to the extended position. There is a rotary cultivator in which the extended leveling part is biased by a torsion coil spring in a direction in which the extended leveling part is rotated from the retracted position to the extended position in the entire rotation range of the extended leveling part (see Patent Document 1).
Japanese Patent Laid-Open No. 2005-130824

  In the conventional rotary cultivator, the biasing means for biasing the extended leveling portion in the direction to rotate the extended leveling portion to the extended posture is configured by a torsion coil spring, and the extended leveling portion is changed from the extended posture to the retracted posture. In the process of changing the posture, the spring force of the torsion coil spring gradually increases proportionally. Therefore, it is not possible to freely set an operation force when changing the posture of the extended leveling portion between the extended posture and the retracted posture. In addition, the spring force of the torsion coil spring that urges the extended leveling portion in the direction of rotating to the extended posture requires a certain amount of force to suppress soil in the extended posture, and this spring force is required in the extended posture. It is necessary to secure enough.

  For this reason, there exists a problem that the operation force which changes the attitude | position of an extended leveling part is large. Therefore, in view of the above problems, the present invention is such that the extended leveling portion is biased by a spring in a direction in which the extended leveling portion is rotated from the retracted position to the extended position over the entire rotation range of the extended leveling section. An object of the present invention is to provide a work machine that can freely set the operating force when changing the posture of the extended leveling portion between the extended posture and the retracted posture to some extent.

The technical means taken by the present invention to solve the technical problem is that the leveling part for leveling the field is a main leveling part, and an extended leveling that extends outward from the main leveling part in the left-right direction. The extended leveling part is rotatable with respect to the main leveling part, and is extended to extend outward from the main leveling part in the left-right direction by rotating and the upper side of the main leveling part. In a work machine that can be changed in posture to the retracted posture located at
The extension leveling portion includes a tension spring that is hooked at one end and the other end is hooked at one end of the link, and the spring force of the tension spring changes the extension leveling portion from the retracted posture to the extended posture. The other end side of the link is supported on the main leveling part side so as to be able to rotate around an axis parallel to the rotation axis of the extended leveling part so as to act in a rotating direction, and the extended leveling part is extended. When rotating from the retracted position to the retracted position, the hook on the other end of the tension spring regulates the rotation of the link just before reaching the dead point where the direction of the spring force of the tension spring switches in the opposite direction. It is characterized by providing a restricting section.

Further, in a state where the rotation of the link is restricted by the restriction portion, the one end side of the link may be bent so that the latching portion on the other end side of the tension spring approaches the dead point.
Further, when the extended leveling portion is rotated from the extended posture to the retracted posture, the rotation of the link is restricted by contacting the rotation support shaft that rotatably supports the extended leveling portion. You may comprise.

  According to the present invention, the moment for rotating the extended leveling section from the retracted position to the extended position by the tension spring is determined by the distance between the rotation axis of the extended leveling section and the axis of the tension spring, and the spring force of the tension spring. Therefore, by changing the setting of the distance between the axis of rotation of the extended leveling part and the axis of the tension spring and the spring force of the tension spring, the extended leveling part can be changed between the extended position and the retracted position. The operating force can be set freely to some extent.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 2, 1 is a rotary tiller (working machine) that is mounted on the rear part of the tractor via a three-point link mechanism so as to be movable up and down.
In the following description, the laterally outward side refers to the direction from the center in the lateral direction of the rotary tiller 1 toward the end in the lateral direction, and the laterally inward side refers to the lateral direction of the rotary tiller 1. A direction from the end toward the center in the left-right direction.
In the rotary cultivator 1 of the present embodiment, support arms 3 are projected left and right from the gear case 2 at the center in the left-right direction, and the upper portion of the transmission case 4 is fixed to the outer end side in the left-right direction of one (left side) support arm 3. In addition, a machine frame 5 that is mainly configured in a gate shape is provided with the upper part of the side frame fixed to the outer end in the left-right direction of the other (right) support arm 3.

A top mast 6 that is bifurcated back and forth is fixed to the upper part of the gear case 2 of the machine frame 5 so as to protrude upward, and the rear end side of the top link of the three-point link mechanism is located at the front upper part of the top mast 6. Top link pins 7 to be connected (or engaged with an upper connected portion provided on the upper side of the hitch frame when the hitch frame is connected to the rear end side of the three-point link mechanism) are provided. Yes.
A connection bracket 8 is fixed to each of the left and right support arms 3, and the rear end side of the left and right lower links of the three-point link mechanism is connected to each of the left and right connection brackets 8 (or to the rear end side of the three-point link mechanism). When the hitch frame is connected, lower link pins 9 are provided (to which the lower connecting portions provided on the left and right sides of the lower side of the hitch frame are connected).

A rotary tiller 10 is provided at the lower part of the machine frame 5, and the rotary tiller 10 is supported between the lower part of the transmission case 4 and the side frame so as to be rotatable about a horizontal axis. And a large number of tilling claws 12 attached to the claw shaft 11.
The gear case 2 of the machine frame 5 is provided with a PIC shaft 13 for inputting power from the PTO shaft of the tractor to the bevel gear transmission mechanism in the gear case 2 via a universal joint or the like. The power input from the PIC shaft 13 is It is transmitted from the bevel gear transmission mechanism to the chain transmission mechanism in the transmission case 4 via the transmission shaft in the left support arm 3, and further transmitted from the chain transmission mechanism to the claw shaft 11 so that the claw shaft 11 is moved in the left-right direction. Is driven to rotate in the direction of arrow A in FIG.

Further, the rotary tiller 1 is provided with a support frame 14 extending rearward from the machine frame 5, and the support frame 14 is pivotally supported by the machine frame 5 so as to be rotatable around a horizontal axis. It can be swung up and down, and can be swung up and down by a lifting operation device 15 provided across the support frame 14 and the top mast 6.
A pair of left and right gauge wheels 16 are attached to the rear end side of the support frame 14.
Further, the rotary tiller 1 is provided with a tillage cover 17 that covers the rotary tiller 10.

The tillage cover 17 includes a main cover 18 that covers the upper side of the rotary tiller 10 and a rear cover 19 that covers the rear side of the rotary tiller 10.
The rear cover 19 is pivotally supported on the side plate 20 fixed to the transmission case 4 and the side frame (to the machine frame 5 side) so that the rear cover 19 is rotatable around a support shaft 21 having a lateral axis. It can swing up and down.
Further, the rotary tiller 1 is provided with a pair of left and right lowering devices 24 for urging the rear cover 19 downward (in the grounding direction).

A leveling member 22 for leveling the field is detachably attached to the lower end side of the rear cover 19.
As shown in FIG. 3, the leveling member 22 includes a leveling unit 23 that contacts the field and levels the field, and an attachment device 24 for detachably mounting the leveling unit 23 to the rear cover 19. Yes.
The leveling portion 23 is disposed on the rear side of the lower end of the rear cover 19 and is attached to the left and right sides of the main leveling portion 25 and the main leveling portion 25 formed to have a left and right width corresponding to the left and right width of the rear cover 19. And an extended leveling portion 26.

The extended leveling portion 26 is attached to the main leveling portion 25 so as to be rotatable about a rotation axis X orthogonal to the left-right direction, and extends outward from the main leveling portion 25 in the left-right direction by rotating. The posture can be changed between an extended posture (see a solid line in FIG. 1 or FIG. 4) and a retracted posture (see a virtual line in FIG. 4 or FIG. 7) located above the main leveling unit 25.
As shown in FIG. 6, the main body portions 27 </ b> A and 27 </ b> B of the main leveling portion 25 and the extended leveling portion 26 are formed by deforming a metal pipe material by a pressing method (pressing) or a drawing method (drawing). The lower wall 27a is formed in a circular shape with a large curvature that protrudes downward in a side view, and is formed in a circular shape that is long in the front and rear in a side view. The lower surface of 27a is a ground leveling surface 28 that contacts the field and levels the ground.

In addition, the front upper ends of the main body portions 27A and 27B of the main leveling portion 25 and the extended leveling portion 26 are formed so that the upper and lower wall portions are in close contact with each other, and the upper front end of the main body portion 27A of the main leveling portion 25 The side is arranged so as to cover the lower end side of the rear cover 19.
The left and right sides of the main body portions 27A and 27B of the main leveling portion 25 and the extended leveling portion 26 are open, and the left and right sides of the main body portion 27A of the main leveling portion 25 are closed by a closing plate 29. The main body portion 27B is closed on the outer end side in the left-right direction by the closing plate 30 and open on the inner end side in the left-right direction, and is in contact with the closing plate 29 of the main leveling portion 25 in the extended posture.

Note that the inner end side in the left-right direction of the extended leveling portion 26 may also be closed with a closing plate.
A pair of left and right mounting devices 24 are provided on the main leveling portion 25 and are detachably attached to a mounting portion 31 provided on the lower rear side of the rear cover 19.
As shown in FIGS. 1 and 4 to 7, a fixing bracket 32 is provided on the outer side of the main leveling portion 25 in the left-right direction, and a rotation support shaft 34 having an axis X orthogonal to the left-right direction is provided. The swing brackets 33A and 33B are pivotally supported by the fixed bracket 32, and the swing brackets 33A and 33B are fixed to the upper surface of the extension leveling portion 26 on the inner side in the left-right direction. , 33B is rotated about the axis X of the rotation support shaft 34 so that the extended leveling portion 26 can be changed between an extended posture and a retracted posture.

The fixed bracket 32 includes a bottom wall 32a fixed to the upper surface of the main leveling portion 25, and support walls 32b rising from both front and rear ends of the bottom wall 32a.
The swing brackets 33A and 33B are provided in a pair of front and rear, and are disposed on opposite sides of the support walls 32b of the fixed bracket 32. When the extended leveling portion 26 is in the extended posture, The rotating support shaft 34 passes through the upper side and the upper side of the support wall 32b before and after the fixed bracket 32, and the lower end side of the swing bracket 33 is fixed to the inner side in the left-right direction on the upper surface of the extended leveling portion 26. Thus, the swing bracket 33 is supported by the fixed bracket 32 so as to be rotatable about the rotation support shaft 34, and the extended leveling portion 26 is configured to rotate integrally with the swing bracket 33. .

The upper side of one (front side) swing bracket 33A has an axial center X of the rotation support shaft 34 (the rotation of the extension leveling portion 26) when the extension leveling portion 26 is in the extended posture. The fan has a circular arc shape centering on the axis of movement X), and a wire guide 35 is provided on the rear surface side of the fan-shaped portion along the circular arc surface of the fan-shaped portion.
In a state where the extended leveling portion 26 is in the extended posture, one end side of the inner wire 37 of the operation wire 36 made of a Bowden wire or the like is wound around the wire guide 35.
A connecting member 38 is fixed to one end of the inner wire 37.

On the other hand, a pivotal support 39 having an axis parallel to the axis X of the pivotal support shaft 34 is provided on the lower side of the swing bracket 33, and a connecting member on one end of the inner wire 37 is provided on the pivotal support 39. 38 is pivotally connected so as to be rotatable about an axis.
One end side of the outer wire 40 of the operation wire 36 is fixed to an outer receiver (not shown) provided in the main leveling portion 25.
Accordingly, when the inner wire 37 is pulled in a state where the extended leveling portion 26 is in the extended posture (FIG. 1), the extended leveling portion 26 is moved together with the swing bracket 33 from the upper side of the main leveling portion 25. It rotates inward in the left-right direction, and changes its posture to the retracted posture (FIG. 7).

Further, the rotary tiller 1 is provided with a tension spring 41 (tensile coil spring) that urges the extended leveling section 26 in a direction to rotate the extended leveling portion 26 from the retracted position to the extended position.
The hooking portion 42 on one end side of the tension spring 41 is hooked on the first spring hooking portion 44 of the spring hooking member 43 fixed to the upper surface side of the extension leveling portion 26, and the hooking portion on the other end side of the tension spring 41 is held. The stop 45 is hooked to a spring hook 47 on one end side of the link 46.
The spring hooking member 43 and the link 46 are formed of a plate material, and the first spring hooking portion 44 and the spring hooking portion 47 are configured by forming holes.

In addition, a link stay 48 rising from the bottom wall 32 a of the fixed bracket 32 is provided between the front and rear support walls 32 b of the fixed bracket 32, and the other end side of the link 46 is connected to the rotation support shaft 34. A pivot 49 having an axis Y parallel to the axis X is pivotally connected around the axis Y of the pivot 49 so as to be rotatable.
The spring hook member 43 is located at substantially the same position as the link 46 in the front-rear direction.
In the state where the extended leveling portion 26 is in the extended posture, the link 46 is disposed below the rotation support shaft 34, and the pivot portion (the pivot shaft 49) of the link 46 is inward in the left-right direction with respect to the rotation support shaft 34. Located on the side.

Accordingly, the spring force of the tension spring 41 acts in a direction in which the extended leveling section 26 is rotated from the retracted position to the extended position in a state where the extended leveling section 26 is in the extended position. The extended leveling portion 26 is held in an extended posture with its rotation restricted by the inner end side in the left-right direction coming into contact with the outer end side in the left-right direction of the main leveling portion 25.
When the extended leveling portion 26 is rotated from the extended posture to the retracted posture side, the extended leveling portion 26 rotates about the axis X of the rotation support shaft 34, and the link 46 and the tension spring 41 are linked to the link 46. As shown in FIG. 8, in the middle of the extended leveling portion 26 from the extended posture to the retracted posture side, the acting direction of the spring force of the tension spring 41 is reverse. The link 46 is configured to come into contact with the rotation support shaft 34 before the dead point at which switching is made.

That is, when the latching portion 45 on the other end side of the tension spring 41 is positioned on the dead point line L which is a line segment orthogonal to the axis X of the pivot shaft 34 and the axis Y of the pivot 49. The position is a dead point that is a boundary where the direction of the spring force of the tension spring 41 switches, and the tension spring does not exceed this dead point (so that the axis e of the tension spring 41 does not exceed the dead point line L). The link 46 is brought into contact with the rotation support shaft 34 and the rotation thereof is restricted before the latching portion 45 on the other end side 41 reaches the dead point.
Therefore, in the present embodiment, the portion of the rotating support shaft 34 that contacts the link 46 is the restricting portion 50 that restricts the rotation of the link 46, and the rotating support shaft 34 is the extended leveling portion. 26 is used both as a member for rotatably supporting 26 and a member for restricting the rotation of link 46.

The restricting portion 50 may be provided on a member different from the rotation support shaft 34.
Further, since the latching portion 45 on the other end side of the tension spring 41 does not exceed the dead point, the spring force of the tension spring 41 retracts the extended leveling portion 26 even after the link 46 contacts the rotation support shaft 34. It acts in the direction to rotate from the posture to the extended leveling part 26.
Therefore, the spring force of the tension spring 41 always acts in the direction in which the extended leveling section 26 is rotated from the extended position to the retracted position in the entire rotation range of the extended leveling section 26. When the pulling operation force 37 is released, the extended leveling portion 26 is configured to rotate back to the extended posture by the spring force of the tension spring 41.

Further, the front side of the front swing bracket 33A is provided with a contact 52 for restricting the rotation of the swing bracket 33A by contacting the fixed bracket 32 in the retracted position.
In FIG. 8, a shows the locus of the first spring hooking portion 44 of the spring hooking member 43, and b shows the distance between the first spring hooking portion 44 of the spring hooking member 43 and the pivot 49 in the extended posture, and An arc line centering on the axis Y of the pivot 49 is shown, and d is a first spring hook portion 44 of the spring hook member 43 and a spring hook portion of the link 46 in a state where the link 46 is in contact with the rotation support shaft 34. An arc line centering on the center of the hole forming the spring hooking portion 47 of the link 46 with the distance from the radius 47 as a radius is shown.

  As shown in FIG. 8, in the present embodiment, the spring force of the tension spring 41 gradually increases in the process of the extended leveling portion 26 from the extended posture to the retracted posture. The distance h between the center X and the axis e of the tension spring 41 gradually decreases in the region g from the extended posture until the link 46 comes into contact with the rotation support shaft 34, and the link 46 contacts the rotation support shaft 34. In the region n from contact to the retracted posture, the distance h gradually increases from the midway portion to the retracted posture from the midway portion until the link 46 contacts the rotation support shaft 34. Until this time, the distance h gradually decreases.

  As a result, the spring force of the torsion coil spring that biases the extended leveling portion to the extended posture gradually increases proportionally in the process of changing the extended leveling portion from the extended posture to the retracted posture. On the other hand, in the example of the present embodiment, as shown in FIG. 10, the moment for rotating the extended leveling portion 26 from the retracted position to the extended position by the tension spring 41 is rotated by the link 46 from the extended position. In the region g until it comes into contact with the moving support shaft 34, it gradually increases until it reaches the midway portion and gradually decreases from the midway portion, and the retracted posture after the link 46 contacts the rotating support shaft 34. Also in the region n up to, it is set so that it gradually increases until it reaches the middle part and gradually decreases from the middle part.

In FIG. 10, the rotation angle of the extended leveling portion 26 is 0 ° when the extended leveling portion 26 is in the extended posture.
In addition, the moment by the tension spring 41 in the retracted posture is such that the extended leveling portion 26 rotates to the extended posture in consideration of the weight of the extended leveling portion 26 and the weight of mud adhering to the extended leveling portion 26. Is set.
Further, in the present embodiment, in a state where the link 46 is in contact with the rotation support shaft 34, the moment due to the weight of the extended leveling portion 26 acts in the direction of rotating the extended leveling portion 26 to the extended posture.

Further, one end side of the link 46 is bent so that the latching portion 45 on the other end side of the tension spring 41 approaches the dead point in a state where the rotation of the link 46 is restricted by the restriction portion 50. Therefore, the operation force at the midpoint of the rotation range of the extended leveling portion 26 is reduced.
In the present embodiment, the moment for rotating the extended leveling section 26 from the retracted position to the extended position by the tension spring 41 is the distance h between the rotation axis X of the extended leveling section 26 and the axis e of the tension spring 41. Because of the product of the spring force of the tension spring 41, the setting of the link 46 and the tension spring 41 (for example, the material, wire diameter, outer diameter, number of turns or free length of the tension spring 41, the latching position of the tension spring 41) By changing the length of the link 46, the pivot position or the restriction position, etc.), the spring force of the tension spring 41 and the rotation axis X of the extended leveling portion 26 and the axis e of the tension spring 41 are changed. The distance h can be changed and the extension leveling section 26 can be rotated by the tension spring 41 during the period from the extended position to the retracted position while ensuring a sufficient restraining force against the soil in the extended position of the extended leveling section 26. Set moment as appropriate Thus, the operating force for changing the posture of the extended leveling portion 26 from the extended posture to the retracted posture can be freely set to some extent, and the posture of the extended leveling portion 26 can be changed. The operating force can be made lighter than before.

Moreover, in the conventional rotary tiller, the torsion coil spring urges the extended leveling portion in the direction to rotate from the retracted position to the extended position, and it is difficult to assemble the torsion coil spring in a twisted state. In the present embodiment, the tension spring 41 is assembled by engaging one end side with the spring hooking member 43 and the other end side with the link 46, and the assembly is relatively easy.
In the present embodiment, the link 46 is removed, and one end of the tension spring 41 is hooked on the second spring hook 51 of the spring hook member 43 and the other end of the tension spring 41 is hooked on the link stay 48. By stopping, the extended leveling portion 26 can be changed to a type that can be held in the extended posture and the retracted posture by the urging force of the tension spring 41.

In this case, when the extended leveling portion 26 is rotated, the rotation support shaft 34 is removed so that the tension spring 41 does not contact the rotation support shaft 34, and the front support wall 32b is swung forward. A shaft for supporting the moving bracket 33A and a shaft for supporting the rear swing bracket 33B are separately provided on the rear support wall 32b.
Further, in this case, the extended leveling unit 26 does not use the operation wire 36, but the operator holds the extended leveling unit 26 by hand and performs the posture changing operation.
In the present embodiment, the other end of the operation wire 36 is operated by an operation lever 54 provided on the top mast 6 so that the posture changing operation of the extended leveling portion 26 can be remotely operated from the seat of the tractor. Has been.

Further, a pair of left and right operation levers 54 are provided, the left extended leveling portion 26 is operated by the left operation lever 54, and the right extended leveling portion 26 is operated by the right operation lever 54.
As shown in FIG. 9, a pair of left and right support brackets 55 are fixed to the rear upper part of the top mast 6, and the upper part of each support bracket 55 is operated via a lever support shaft 56 having a horizontal axis. The base side of the lever 54 is supported so as to be rotatable around the axis of the lever support shaft 56.

A grip 57 is provided on the distal end side of the operation lever 54.
In addition, a wire guide 58 is provided on one side surface of the operation lever 54 on the base side. The wire guide 58 includes an arcuate winding portion 58a centering on the axis of the lever support shaft 56, and the winding portion. A wire locking portion 58b extending in a tangential direction from one end side of 58a, and a locking tool 59 provided on the other end side of the inner wire 37 of the operation wire 36 is detachably attached to the wire locking portion 58b. It is locked.
A wire holder 60 to which the other end side of the outer wire 40 of the operation wire 36 is attached is held on the lower side of the rear portion of the support bracket 55 so as to be rotatable about an axis in the left-right direction.

When the extended leveling portion 26 is in the extended posture, as shown in FIG. 9, the operation lever 54 is in the non-operating position extending rearward and the other end side of the inner wire 37 is wound around the winding portion 58a. It is said that it is not done.
With the rotary cultivator 1 mounted on the tractor, the rotary cultivator 1 is lifted from the tractor's seat to a position where the hand reaches the grip 57 of the operation lever 54, and the operation lever 54 is moved in the direction of arrow B from the non-operation position. When rotated, the inner wire 37 is pulled and the extended leveling section 26 is changed in posture from the extended posture to the retracted posture.

At this time, the other end side of the inner wire 37 is wound around the winding portion 58 a of the wire guide 58.
Further, the operation lever 54 is locked by a lever locking portion 61 provided on the lower front side of the support bracket 55 so as not to return to the non-operation position at the operation position where the extended leveling portion 26 is operated to the retracted position. Keep it.
In the present embodiment, the rotary cultivator 1 of the type in which the leveling member 22 provided with the leveling part 23 is detachably provided on the lower end side of the rear cover 19 is illustrated, but is limited to this type. For example, there is a rear cover 19 of a type in which the leveling member 22 is not detachably attached to the lower end side of the rear cover 19, and the lower end side of the rear cover 19 is the main leveling portion and the main leveling portion. You may employ | adopt this invention to working machines, such as the rotary tiller 1 of the type in which the extended leveling part was attached to the right-and-left both sides of the leveling part so that rotation was possible.

Further, in this case, notches for attaching the piece cultivator to the rotary tiller 1 and the like are provided on both the left and right sides of the rear cover 19, and a closing cover for closing the notch when the piece cultivator is not attached is provided. In the case of the rear cover 19 having the type, the extended leveling portion is rotatably attached to the closing cover.
In the present invention, the leveling portion 23 provided on the lower end side of the rear cover 19 includes a main leveling portion 25 and an extended leveling portion 26 extending outward from the main leveling portion 25 in the left-right direction. Thus, the extended leveling portion 26 is rotatable with respect to the main leveling portion 25, and is extended to extend outward from the main leveling portion 25 in the left-right direction by rotating, and on the upper side of the main leveling portion 25. The present invention can be employed in a working machine that can be changed in posture to a retracted posture.

FIGS. 11 to 14 show a posture changing mechanism of the extended leveling unit 26 of a type different from the above embodiment.
Also in the posture changing mechanism of the extended leveling portion 26 shown in FIGS. 11 to 14, the fixing brackets 32 are provided on the left and right ends of the main leveling portion 25, and the left and right extended leveling portions 26 are orthogonal to the left-right direction. Oscillation brackets 33A and 33B are rotatably supported by the fixed bracket 32 via a pivot support shaft 34 having an axis, and the extended leveling portion 26 is turned to the main leveling portion 25 by a rotation support shaft. 34 is supported so as to be rotatable about 34, and the extended leveling portion 26 is rotated about the rotation support shaft 34, whereby the extended leveling portion 26 can be changed in posture between an extended posture and a retracted posture. .

The fixing bracket 32 includes a bottom wall 32a fixed to the upper surface side of the main leveling portion 25, and a pair of support walls provided in a front-rear facing manner extending upward from both front and rear edges of the bottom wall 32a. 32b and a U-shape.
Of the pair of front and rear swing brackets 33 </ b> A and 33 </ b> B, the front swing bracket 33 </ b> A is disposed on the front side of the front support wall 32 b of the fixed bracket 32, and the rear swing bracket 33 </ b> B is the rear side of the fixed bracket 32. The rotating support shaft 34 passes through the front and rear swing brackets 33A, 33B and the support wall 32b.

The contact 52 is provided in each swing bracket 33A, 33B.
A rotating member 63 made of a plate material is disposed on the inner side in the opposing direction of the support wall 32b on the front side of the fixed bracket 32. The rotating member 63 is supported by the rotating support shaft 34 so as to be rotatable about the axis. Yes.
A guide tube 64 is provided between the rotating member 63 and the rear support wall 32 b so as to cover the rotating support shaft 34. The front end side of the guide tube 64 is connected to the rotating member 63. A disc-shaped closing plate 65 is provided on the rear end side of the guide tube 64 so as to close the opening on the end portion side, and the closing plate 65 is rotatable around the rotation support shaft 34 around its axis. It is supported.

The guide cylinder 64 is fitted with a torsion coil spring 66, and one end side of the torsion coil spring 66 is in contact with the upper surface of the main leveling portion 25, and the other end side of the torsion coil spring 66 is swung rearward. The spring force of the torsion coil spring is engaged with the bracket 33B and acts in a direction to rotate the extended leveling portion 26 from the retracted position to the extended position in the entire region of the rotation range.
A mounting pin 67 is provided at the lower part of the rotating member 63, and a connecting member 38 on one end side of the inner wire 37 of the operation wire 36 can be relatively rotated around the axis of the mounting pin 67. It is connected.

In addition, a wire guide 35 that is formed in a substantially arc shape around the rotation support shaft 34 and guides the inner wire 37 is provided on the upper portion of the rotation member 63.
A pushing portion 68 that contacts the extended leveling portion 26 is provided at the lower end portion of the rotating member 63.
A tension spring 69 (tensile coil spring) is disposed on the front side of the front swing bracket 33A.
The hooking portion 70 on one end side of the tension spring 69 is hooked on the spring hooking portion 72 of the first spring hooking member 71 erected on the upper surface side of the extended leveling portion 26, and the hooking portion on the other end side of the tension spring 69. The stop portion is hooked on a spring hook portion 75 of a second spring hook member 74 provided upright on the upper surface side of the main leveling portion 25.

The first and second spring hook members 71 and 74 are made of a plate material, and the spring hook portions 72 and 75 are formed by forming holes.
The spring hooking portion 75 of the second spring hooking member 74 is located on the inner side in the left-right direction below the rotation support shaft 34, and the spring leveling force of the tension spring 69 is extended by the extended leveling portion 26. In this state, the extended leveling section 26 acts in the direction of rotating from the retracted position to the extended position.
Therefore, in the posture changing mechanism of the extended leveling portion 26 configured as shown in FIGS. 11 to 14, the extended leveling portion 26 is moved by the torsion coil spring 66 and the tension spring 69 when the extended leveling portion 26 is in the extended posture. Is biased in the direction of rotating from the retracted position to the extended position.

  Further, in the posture changing mechanism of the extended leveling portion 26 configured as shown in FIGS. 11 to 14, when the extended leveling portion 26 is in the extended posture, the inner wire 37 is wound around the outer peripheral side of the wire guide 35. When the other end side of the inner wire 37 is pulled from this state, one end side of the inner wire 37 is connected to the rotating member 63, so that the rotating member 63 is rotated around the axis of the rotating support shaft 34. The extended leveling portion 26 rotates in a direction to rotate from the extended posture to the retracted posture, the rotating member 63 rotates, and the pushing portion 68 presses the extended leveling portion 26, thereby extending the extended leveling portion 26. Rotate from posture to retracted posture.

  At this time, the spring force of the torsion coil spring 66 gradually increases, but the moment (the spring force of the tension spring 69 and the axis of the tension spring 69) that causes the extension leveling portion 26 to rotate from the retracted position to the extended position by the tension spring 69. (The product of M and the distance P between the axis X of the rotation support shaft 34) and the rotation support shaft 34 are set so as to be gradually reduced. When the axis M of the tension spring 69 passes through the dead point line L passing through the axis X of the shaft 34 and orthogonal to the axis X of the rotation support shaft 34 and the center of the spring hook 75, the spring force of the tension spring 69 is increased. Are switched so that the spring force of the tension spring 69 acts in a direction to rotate the extended leveling portion 26 from the extended position to the retracted position, and the extension leveling portion 26 is changed by the tension spring 69. Extension Moment to rotate to the retracted position from the work.

Thus, the operation force when the extended leveling unit 26 is changed between the extended posture and the retracted posture can be reduced.
Further, in the retracted position, the moment that acts to rotate the extended leveling section 26 from the retracted position to the extended position by the torsion coil spring 66 is rotated by the tension spring 69 from the extended position to the retracted position. It is set to be larger than the sum of the moment that acts to move and the moment that acts to rotate the extended leveling portion 26 from the extended posture to the retracted posture due to its own weight. When the pulling operation force with respect to the extended leveling portion 26 by the inner wire 37 is released from the retracted posture state, the extended leveling portion 26 is rotated to the original extended posture.

The spring force of the torsion coil spring is set assuming mud adhering to the extended leveling portion 26.
In the configuration shown in FIGS. 11 to 14, the torsion coil spring 66 is removed so that the extended leveling portion 26 can be held in the extended posture and the retracted posture by the urging force of the tension spring 69. Can be changed.
In this case, the tension spring 69 is replaced with one having a strong spring force so that a moment sufficient for the extended leveling portion 26 to suppress the soil is generated only by the tension spring 69 in the extended posture.

It is a rear view of the attachment part of the extended leveling part in an extended attitude | position. It is a side view of a rotary tiller. It is a top view of the attachment part of a leveling member. It is a rear view of the attachment part of the extended leveling part in an extended attitude | position. It is a top view of the attachment part of an extension leveling part. It is a side view of the attachment part of an extended leveling part. It is a rear view of the attachment part of the extension leveling part in a retracted posture. It is a rear view which shows the motion of a link and a tension spring. It is a side view of the operation part of an extension leveling part. It is a graph which shows the moment by a tension spring. It is a rear view which shows another type of extended leveling part attitude | position change mechanism. It is a top view which shows another type of extended leveling part attitude | position change mechanism. It is a side view which shows another type of extended leveling part attitude | position change mechanism. It is a rear view which shows another type of extended leveling part attitude | position change mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 23 Leveling part 25 Main leveling part 26 Extension leveling part 34 Rotating spindle 41 Tension spring 46 Link 50 Control part X The axis of rotation of the extension leveling part

Claims (3)

The leveling part (23) for leveling the agricultural field comprises a main leveling part (25) and an extended leveling part (26) extending outward from the main leveling part (25) in the left-right direction, The extended leveling part (26) is rotatable with respect to the main leveling part (25), and when extended, the extended leveling part (26) extends outward from the main leveling part (25) in the left-right direction and the main leveling part ( 25) In the working machine that is changeable in posture to the retracted posture located on the upper side of
The extension leveling portion (26) is provided with a tension spring (41) whose one end is hooked on one end of the link (46) and whose other end is hooked on one end of the link (46), and the spring force of the tension spring (41) is extended. The other end side of the link (46) is directed to the main leveling part (25) side so that the extended leveling part (26) is rotated in the direction from the retracted position to the extended position. The other end of the tension spring (41) is supported so as to be rotatable about an axis parallel to the rotation axis (X) and when the extended leveling portion (26) is rotated from the extended position to the retracted position. A restricting portion (50) for restricting the rotation of the link (46) is provided just before the latching portion (45) reaches a dead point where the direction of action of the spring force of the tension spring (41) switches to the opposite direction. A working machine characterized by that.   In the state where the rotation of the link (46) is restricted by the restricting portion (50), the link (46) of the link (46) is moved so that the latching portion (45) on the other end side of the tension spring (41) approaches the dead point. The working machine according to claim 1, wherein one end side is bent.   When rotating the extended leveling section (26) from the extended position to the retracted position, the link (46) contacts the rotating support shaft (34) that rotatably supports the extended leveling section (26). The working machine according to claim 1 or 2, wherein the rotation of the link (46) is restricted by the above.

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