JPH09233902A - Rotary tilling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the lower part of a rotary case in a narrow, thin, and long shape. SOLUTION: At the lower part 10a of a center case 10 connected to a transmission case 2, 1st and 2nd rotary shafts 11 and 12 which rotate in mutually opposite directions are projected coaxially, and a 1st rotary claw 13 and a 2nd rotary claw 14 are fitted to both the rotary shafts 11 and 12. Power is transmitted through a sprocket 51 and a chain 52 to the 1st rotary shaft 11, which is rotated. A 1st side gear composed of a bevel gear is fixed to the sprocket 51 and a 2nd side gear is connected to the 2nd rotary shaft 12; and a center gear engages those 1st and 2nd side gears. Consequently, when the 1st rotary shaft 11 rotates in one direction, the 2nd side gear rotates in the other direction through the 1st gear and center gear, so that the 2nd rotary shaft 12 rotates in the other direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cultivating apparatus, and more specifically, a first and a second rotary shafts are coaxially projected behind a transmission case, and the rotary shafts have the first and second rotary shafts respectively. The present invention relates to a rotary tiller equipped with a second rotary claw.

[0002]

2. Description of the Related Art A plurality of rotary pawls are attached to a rotary shaft of a tiller, and some of the rotary pawls can be rotated in the same direction as the traveling direction of the machine body or can be switched to the reverse direction. As a technique for cultivating while suppressing the dash phenomenon of the airframe, for example, a technique described in Japanese Patent Laid-Open No. 6-303801 is known.

According to this conventional example, as shown in FIG. 13, first rotary shafts 11, 11 are protrusively provided on the left and right of a center case 10 connected to a transmission case. A plurality of first rotary claws 13 are attached to the shaft 11. A second rotary shaft 12 is rotatably arranged on the outer peripheral side of the first rotary shaft 11, and a second rotary claw 14 is attached to the second rotary shaft 12.

As shown in FIG. 14, the first rotary shaft 11 is normally driven by a sprocket 51 and a chain 52, and the second rotary shaft 12 is splined to the sprocket 51 or the sprocket 51. A reverse gear 80 that rotates in the opposite direction to the sprocket 51 and a switching gear 81 that can freely engage and disengage are provided. Then, the switching gear 81 is moved to the sprocket 5 by the shifter 82.
The second rotary shaft 12 can be normally or reversely driven by selectively switching and connecting the first rotary shaft 12 or the reverse gear 80.

[0005]

However, according to the above-mentioned conventional example, in order to dispose the second rotary shaft 12 on the outer peripheral side of the first rotary shaft 11 so as to freely rotate forward and backward, the switching gear 81 is provided. There is a problem that the structure becomes complicated, such as spline connection to the second rotary shaft 12 or provision of a shifter 82 for sliding the switching gear 81.

Further, in the structure of the conventional example, since it is necessary to house the reverse gear 80, the switching gear 81, etc. in the center case 10, the left and right width of the lower part of the center case 10 becomes huge, and for example, the second rotation is performed. There is a risk that the claw 14 may be held by the upper surface of the lower portion of the center case 10 in which the soil that has been flipped up toward the front of the vehicle is enormous and the vehicle may be stacked.

The present invention has been made to solve the above problems, and its object is to reduce the amount of mud adhered to the rotary case as much as possible and to surely adhere the mud to the rotary case. Another object of the present invention is to provide a rotary tiller that can be scraped off, and another object is to attach rotary pawls to two rotary shafts that rotate in opposite directions coaxially with each other, so that even if the field conditions are different, they can be fixed. It is an object of the present invention to provide a rotary tiller capable of ensuring the tilling performance.

[0008]

In order to achieve the above object, the present invention provides a lower part (1) of a center case (10) connected to a transmission case (2).
0a) is provided with a first rotary shaft (11) and a second rotary shaft (12) that rotates in the opposite direction to the first rotary shaft (11) coaxially with each other.
In the rotary cultivator in which the first rotary claw (13) and the second rotary claw (14) are attached to the first rotary claw (12) and the second rotary claw (14) respectively, a rotary member (51) fixed to the first rotary shaft (11)
A winding member (52) for transmitting power from a transmission to the sprocket (51), and a first side gear (5) arranged on both sides of the rotating member (51).
3) and a sleeve shaft (12) in which the second rotary shaft (12) is rotatably supported by the first rotary shaft (11) and rotates integrally with the sleeve shaft (12). Second side gear (55) operably connected
And a center gear (60) which meshes with the first and second side gears (53, 55) and is supported by the lower part (10a) of the center case.

Preferably, the rotation direction of the rotating member (51) can be switched forward and backward by switching the transmission path of the gears in the transmission by operating the switching lever (31).

Further, preferably, the center case (10) is formed in a narrow and elongated shape by accommodating a winding member (52) inside.

Further, preferably, the first rotary claw (1
3) and the second rotary pawl (14) are provided with a blade (2
3) having a heart-shaped plate-like body in a plan view, the front end side is curved to one side surface, and the base end portion has a mounting hole (24) to the first or second rotary shaft (11, 12). ) Should be provided.

Furthermore, preferably, the inside of the second rotary claw (14) and the lower part of the center case (10) are used.
It is preferable to attach the mud dropping claw (18) at a position facing a).

(Operation) With the above construction, in the present invention, the transmission case (2) of the cultivator (1), etc.
A rotary tiller is continuously provided behind the center case (10) through the center case (10).
On the lower portion (10a) of the above, a first rotary shaft (11) and a second rotary shaft (12) that rotates in the opposite direction to the first rotary shaft (11) are coaxially projected. A first rotary claw (13) and a second rotary claw (14) are attached to the rotary shafts (11, 12).

A rotating member (51) is fixed to the first rotary shaft (11), and a winding member (52) is wound around the rotating member (51), and the winding member (52). Thus, the power from the transmission is transmitted to the first rotary shaft (11).

A first side gear (53) made of, for example, a bevel gear is disposed on both sides of the rotating member (51), while the second rotary shaft (12) is integrally formed with the first side gear (53). A rotatable second side gear (55) is connected and these first and second side gears (53,
The center gear (60) supported by the lower part (10a) of the center case is meshed with 55).

Therefore, when the power of the transmission causes the first rotary shaft (11) to rotate in one direction around its axis, the first side gear (53).
Through the center gear (60) and the second side gear (5
5) rotates in the other direction and this second side gear (55)
A second rotary shaft (1
2) rotates in the other direction. That is, the first rotary shaft (11) and the second rotary shaft (12) always rotate in opposite directions.

At this time, the first side gear (53), the center gear (60), and the second side gear (55) forming the reversing mechanism are meshed with each other via, for example, bevel gears. Therefore, it is possible to set the turning radius of each gear from the first rotary shaft center to be small, and thus the center case (1) housing the first side gear (53) and the center gear (60).
0) can be formed in a narrow and narrow shape.

Inside the second rotary pawl (14) attached to the second rotary shaft (12), the mud-dropping pawl (1) is placed at a position facing the lower part (10a) of the center case.
8) is attached, the mud removing claws (18) scrape off the mud adhered to the center case (10).

The rotation direction of the first rotary shaft (11) is changed by operating the switching lever (31) to switch the transmission path of the gears in the transmission.
It can be switched forward and backward freely, and accordingly, the second rotary shaft (12) rotates in a direction opposite to the rotation direction of the first rotary shaft (11).

Further, the first rotary claw (13) and the second rotary claw (14) form a heart-shaped plate-like body in plan view having the blades (23) at the front and rear of the rotation direction. The tilling performance does not change regardless of whether the first and second rotary shafts (11, 12) rotate forward or backward.

The reference numerals in the above parentheses are for the purpose of comparing the drawings, but do not limit the structure of the present invention.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. Note that members that are the same as or correspond to those of the above-described conventional example are denoted by the same reference numerals and described.

FIG. 1 shows an outer appearance of a cultivator 1 to which the present invention is applied. The cultivator 1 is provided with a transmission case 2, an engine 3, running wheels 5, and a rear side of a transmission case 2 which constitute a body frame. It is provided with a rotary tilling device 6, a handle 7, a rotary tilling depth regulating device 9 and the like provided in the lower part. In addition, from the output pulley of the engine 3 to the input shaft 29 (see FIG.
A tension / relaxation belt is wound around a pulley 4 (see FIG. 3) fixed to the belt 4 and the pulley 4 (see FIG. 3), and the belt and the pulley 4 are covered with a case 30.

Further, a speed change lever 31 extends from the upper part of the transmission case 2 along the upper side of the handle 7, and the speed change lever 31 is attached to the fuel tank 32 above the engine 3 and the transmission case 2. It is guided by the guide groove 35 of the plate 33.

The guide groove 35, as shown in FIG.
The lateral direction (the left-right direction in the figure) is composed of a traveling gear position having a forward first speed position F ₁ , a forward second speed position F ₂ , a neutral position N, a reverse position R and a working neutral position N ′, and a vertical direction (vertical direction). ) Comprises a rotary rotation direction switching stage having a forward rotation position S, a neutral position N _R and a reverse rotation position C. The shift lever 31 has a base end in a U-shape, and is connected to a shift fork (not shown) so as to be rotatable in the vertical direction and integrally linked in the horizontal direction.

Further, as shown in FIGS. 3 and 12, the transmission case 2 is provided with a shift shift shaft 41 over both side surfaces thereof, and a shift fork (not shown) is attached to the shift shaft 41 by a click mechanism. It is slidably inserted. This shift fork is engaged with a traveling shifter gear 46 that is spline-coupled to the input shaft 29 so that it can slide only.

Further, adjacent to the shift shift shaft 41,
A rotary shift shaft 26 is provided on both side surfaces of the transmission case 2, and a shift fork (not shown) is slidably fitted to the shift shaft 26 by a click mechanism. This shift fork has an input shaft 29
Is engaged with a rotary shifter gear 63 slidably connected to the rotary shifter gear 63.

As shown in FIG. 3, the shifting shift gear 46 engages with the gear 65 of the output shaft 36 so as to move to the first forward speed F.
₁ , the shift gear 46 is engaged with the gear 47 which is always engaged with the gear 67 of the output shaft 36, the forward second speed F ₂ , and the shift gear 46 is constantly engaged with the gear 69 of the output shaft 36. The reverse R is obtained by engaging with the gear 70 of the intermediate shaft 34 that is engaged.

On the other hand, as shown in FIGS. 3 and 4, the rotary shifter gear 63 engages with the gear 71 of the intermediate shaft 34 to obtain the forward rotation S from the output shaft 36, and the shifter gear 63 is , The reverse rotation C is obtained by directly engaging the gear 73 of the output shaft 36 which is always meshed with the gear 72 of the intermediate shaft 34.

The rotation of the traveling transmission system is controlled by the output shaft 36.
Traveling wheel 5 from the above through a chain and a differential gear
And the rotation of the rotary transmission system is transmitted to the center case 1 connected to the rear of the transmission case 2.
It is transmitted to the rotary cultivator 6 provided at the lower part of the chain 52 through the chain 52 in the 0.

As shown in FIG. 3, the rotary tiller 6 includes a first rotary shaft 11 protruding leftward and rightward in a direction substantially orthogonal to the traveling direction of the machine body, and the first rotary shaft 1.
1 and a second rotary shaft 12 that rotates in the opposite direction,
These are arranged coaxially, and further, a first rotary claw 13 and a second rotary claw 14, 14 'are attached to both rotary shafts 11, 12, respectively.

Here, in the present invention, the rotating member 51 fixed to the first rotary shaft 11 and the winding member 5 for transmitting the power from the transmission to the rotating member 51.
2 and a first side gear 53 fitted to both sides of the rotating member 51.

As shown in FIGS. 3 and 5, a sprocket 51 as a rotating member is integrally fixed to the first rotary shaft 11 by a pin 15, and the sprocket 51 serves as a winding member. The sprocket 50 on the transmission side is connected via the chain 52, and thereby the power from the transmission is transmitted to the first rotary shaft 11. Further, on both sides of the sprocket 51, first side gears 53, 53 made of bevel gears are fitted.

The rotation direction of the sprocket 51 can be switched between the forward and reverse directions as described above by switching the transmission path of the gears in the transmission by operating the shift lever 31.

The present invention also relates to the second rotary shaft 1 described above.
Reference numeral 2 denotes a sleeve shaft rotatably supported by the first rotary shaft 11, and a second side gear 55 integrally rotatably connected to the sleeve shaft and the first side gears 53, 53. And a center gear 60 meshed with the second side gear 55 and supported on the lower part of the center case 10.

Similarly to the above, in FIG. 3 and FIG.
In the present embodiment, the second rotary shaft 12 is composed of a sleeve shaft 12 rotatably supported by the first rotary shaft 11 via a bearing 54 and an oil seal 61. The second side gears 55, 55 are spline-coupled to the. The second side gear 55 is rotatably supported by the first rotary shaft 11 by a needle bearing 56, spline teeth are formed on the outer peripheral portion of one end thereof, and a bevel gear is formed on the other end thereof.

The outer peripheral portion of the second side gear 55 is rotatably supported by the outer cylinder 10b below the center case 10 via a bearing 58 and an oil seal 57.

A shaft 59 is rotatably attached to the first rotary shaft 11 at an intermediate portion of the first rotary shaft 11 between the first side gear 53 and the second side gear 55.
Is fixed to the lower case 10 a of the center case 10. Further, center gears 60, 60 composed of two bevel gears are attached to the attachment shaft 59 at symmetrical positions with respect to the first rotary shaft 11. Further, the center gear 60 meshes with the first side gear 53 and the second side gear 55.

Therefore, the power from the transmission is transmitted to the sprocket 51 via the chain 52,
When the first rotary shaft 11 rotates in one direction about its axis, the second side gear 55 moves in the other direction via the first side gear 53 fitted to the sprocket 51 and the center gear 60 meshing with the first side gear 53. Therefore, the second rotary shaft 12 integrally rotatably connected to the second side gear 55 rotates in the other direction. That is, the first rotary shaft 11 and the second rotary shaft 12 always rotate in opposite directions.

In the above description, the first side gear 53, the center gear 60, and the second side gear 55 forming the reversing mechanism are meshed with each other through the bevel gears. The radius of gyration from the axis of the first rotary shaft 11 can be set small. Therefore, the center case lower portion 10a accommodating the first side gear 53 and the center gear 60 can be formed in an elongated shape having a small volume and a narrow width. Since the center case 10 only accommodates the chain 52 inside, the center case 10 can be formed in a narrow and narrow shape.

The first rotary shaft 11 includes an inner rotary shaft 11 'at the inner center and the inner rotary shaft 1
Outer rotary shaft 1 integrally connected to the left and right outer sides of 1 '
1 ″. The outer rotary shaft 11 ″ has a pipe shape and is fitted into the inner rotary shaft 11 ′, and further, a pin 21 is inserted and connected.

As shown in FIGS. 6 and 7, a pawl mounting plate 22 is fixed to the outer peripheral portion of the outer rotary shaft 11 ″, and the first rotary pawl 13 is mounted on the pawl mounting plate 22. Further, claw mounting plates 16 and 17 are fixed to the outer peripheral portion of the sleeve shaft 12, and the claw mounting plate 16 is provided.
The inner second rotary claw 14 is attached to the
On the pawl mounting plate 17, a second rotary pawl 14 ′, which is slightly outwardly displaced from the rotary pawl 14 and is on the outer side, is attached to the first rotary shaft 11 in a substantially symmetrical position.

These first and second rotary claws 13, 1
4, 14 'have substantially the same shape, and as shown in FIG. 3, when mounted on the first rotary shaft 11 and the sleeve shaft 12, they can rotate on the same circumference with respect to the rotation shaft. I have to.

The second rotary claw 1 is attached to the claw mounting plate 17 to which the outer second rotary claw 14 'is mounted.
A mud dropping claw 18 is attached to the inside of 4 '. As shown in FIG. 6, the mud-dropping claw 18 is on the side where the mounting angles of the inner and outer rotary claws 14 and 14 'are larger than 180 degrees and is substantially equally divided from both rotary claws 14 and 14'. Is installed in the position. Therefore, the three rotary nails 14 and 14 'and the mud-falling nail 18 are divided into three parts, and the rotational balance as a whole is maintained.

As shown in FIGS. 6 and 7, the mud dropping claw 18 is sized so as to move on a circumference smaller than the circumference of rotation of both rotary claws 14 and 14 '. That is, the mud dropping claws 18 serve to drop the mud attached to the center case 10 without plowing.

The first and second rotary claws 13, 14,
The reference numeral 14 'forms a plate-shaped body having a heart shape in plan view having blades at the front and the rear in the rotation direction, and the tip side is curved to one side.

That is, as shown in FIGS. 8 to 11, it is formed of a plate-shaped body having a semi-heart-shaped edge formed symmetrically with respect to the center line X, and its tip side is smoothly formed on one side surface. The blade portions 23, 23 are curved and are formed on both sides of the center line X.

Also, these first and second rotary claws 1
Mounting holes 24, 2 for the first or second rotary shafts 11, 12 are provided at the base end portions on the mounting side of 3, 14, 14 '.
4 are provided. Further, the reinforcing rib 25 having a chevron cross section is formed by bending the base end portion toward the tip side along the center line X. Around the mounting holes 24, 24, there is formed a stepped flat portion with the reinforcing rib 25 (see FIG. 11), and this flat portion is joined to the claw mounting plates 16, 17, 22. Is a face.

Since the present embodiment has the above configuration, the rotation of the engine 3 is transmitted to the input shaft in the transmission case 2 via the belt in the case 30.
When the operator moves the shift lever 31 in the lateral (left / right) direction along the guide groove 35 of the guide plate 33, the left / right movement of the shift lever 31 is transmitted to a shift fork (not shown). It slides along 41 and is positioned at an appropriate position corresponding to the indication on the guide plate 33. For example, when the shift lever 31 is moved to the neutral position N
When the fork moves to the forward second speed position F ₂ , the fork engages the traveling shifter gear 46 with the gear 47 to travel at high speed to adapt the cultivator 1 to the non-work traveling, and when the fork moves to the reverse position R, The shifter gear 46 engages with the gear 70 to move backward. At this time, depending on the left and right movement of the shift lever 31,
The rotary is not affected and is kept at the rotary stop position N _R.

When the shift lever 31 is located at the work neutral position N 'on the guide plate 33,
When the user 1 operates in the vertical (up / down) direction along the guide groove 35, a shift fork (not shown) slides along the shift shaft 26 and is positioned at an appropriate position corresponding to the indication on the guide plate 33. For example, when the shift lever 31 is moved from the neutral position N _R to the forward rotation position S, the shift fork engages the shifter gear 63 with the gear 71 to transmit the rotation in the same direction as the forward direction to the rotary tiller 6. When the shift lever 31 is moved to the reverse rotation position C, the shifter gear 63 engages with the gear 73 to transmit the rotation in the direction opposite to the forward direction to the rotary tiller 6.

[0051] Then, the shift lever 31 in a state of being moved up or down, move the lever 31 in the lateral direction so that the forward first speed position F ₁ along the guide groove 35.

Then, as described above, the shifter gear 46 is shifted via the shift fork so as to engage with the gear 65, and the low-speed rotation suitable for the operation is transmitted to the wheels 5. As a result, the cultivator 1 is moved forward while the rotary cultivator 6 is rotating in the normal rotation or the reverse rotation, and the cultivating work is performed.

By the way, as the field for tilling, the field conditions such as a hard field and a soft field are variously different.
When the rotation direction of the first rotary claw 13 is switched between normal and reverse, the second rotary claws 14 and 14 'rotate in the reverse direction and the normal direction in response to this, so that a certain tilling performance can be secured by the operator's selection. It will be possible. In addition, in this case, the first and second rotary claws 13, 14, 14 ′ have blades 23, 14 before and after the rotation direction.
Since it has a plan view heart shape having 23, the rotary nail 1
Even if the rotation directions of 3, 14 and 14 'are switched to the normal direction, the tilling performance does not change. During the plowing work, mud is generally attached to the lower portion 10a of the transmission case 10, but the attached mud is reliably scraped off by the mud dropping claws 18.

[0054]

As described above, according to the first aspect of the present invention, the first rotary shaft and the second rotary shaft rotating in the opposite direction are coaxially projected from the lower portion of the center case. In the rotary cultivator in which the first and second rotary claws are attached to both rotary shafts, a sprocket is fixed to the first rotary shaft, and a first side gear is fixed to both sides of the sprocket. Further, by connecting a second side gear that is rotatable integrally with the second rotary shaft and having a center gear that meshes with the first and second side gears, a reverse rotation mechanism of the second rotary shaft can be realized. Since the structure can be made compact, the lower part of the center case for accommodating the reversing mechanism can be made narrow and compact.

Therefore, the center case can be formed in an elongated shape with a narrow width from the base portion connected to the transmission case to the lower portion, and the amount of mud adhered to the center case can be reduced. Further, since the center case can be configured to be narrow and compact, the rotary claw can be attached to the center of the rotary shaft, and unevenness in excavation can be eliminated.

According to the second aspect of the present invention, the rotation direction of the first rotary shaft can be switched between forward and reverse by operating the switching lever, and accordingly, the second rotary shaft can be rotated in the reverse and forward directions. With this configuration, it is possible to secure a certain level of tilling performance for various field conditions such as a hard field and a soft field, and it is possible to widen the selection range of the tilling work by the operator.

Further, according to the invention described in claim 4, the first and second rotary claws attached to the rotary shaft form a plate-shaped body having a blade in front and rear in the rotation direction and having a heart shape in plan view. Therefore, even when the rotation direction of the rotary shaft is switched between forward and reverse, the same plowing performance can be exhibited.

Furthermore, according to the invention of claim 5,
By attaching the mud dropping claws to the position facing the center case inside the second rotary claws, it is possible to surely drop the mud adhered to the center case.

[Brief description of drawings]

FIG. 1 is a side view of a cultivator to which the present invention is applied.

FIG. 2 is a front view showing a guide groove of a guide plate.

FIG. 3 is a sectional view of a transmission and a rotary working machine connected to the transmission in a developed state.

FIG. 4 is a side view showing a meshed state of gears in the transmission.

FIG. 5 is an enlarged sectional view of a main part of FIG. 3;

6 is a view in the direction of arrow VI in FIG.

7 is a partially cutaway front view of FIG.

FIG. 8 is a front view of a rotary pawl.

FIG. 9 is a side view of FIG.

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is a sectional view taken along line XI-XI of FIG. 8;

12 is an enlarged cross-sectional view of the main parts of FIG.

FIG. 13 is a front view of a conventional rotary working machine.

14 is an enlarged cross-sectional front view of the main part of FIG.

[Explanation of symbols]

 1 Cultivator 2 Transmission Case 3 Engine 5 Traveling Wheel 6 Rotary Working Machine 10 Center Case 10a Lower Case 10b Outer Cylinder 11, 11 ', 11 "First Rotary Shaft 12 Second Rotary Shaft 13 First Rotating Claw 14, 14 'Second rotary claw 16, 17, 22 Claw mounting plate 18 Mud claw 23 Blade section 26 Rotary shift shaft 29 Input shaft 31 Speed change lever 34 Second shaft 35 Guide groove 36 Third shaft 41 Speed change shift shaft 50, 51 Sprocket 52 Chain 53 First Side Gear 55 Second Side Gear 60 Center Gear

Claims (5)

[Claims] 1. A first rotary shaft and a second rotary shaft, which rotates in a direction opposite to the first rotary shaft, are coaxially projected on a lower portion of a center case connected to a transmission case, A rotary cultivator in which a first rotary claw and a second rotary claw are attached to both rotary shafts, respectively, a rotary member fixed to the first rotary shaft, and a winding member for transmitting power from a transmission to the rotary member. A hanging member, a first side gear arranged on both sides of the rotating member, a sleeve shaft in which the second rotary shaft is rotatably supported by the first rotary shaft, and the sleeve shaft, A second side gear integrally and rotatably connected to the center gear; and a center gear that meshes with the first and second side gears and is supported by a lower part of the center case. , Rotary plow and wherein the. 2. The rotary tiller according to claim 1, wherein the rotation direction of the rotating member can be switched forward and backward by switching the transmission path of the gear in the transmission by operating the switching lever. 3. The rotary tiller according to claim 1, wherein the center case is formed in an elongated shape with a narrow width to accommodate the winding member therein. 4. The first rotary claw and the second rotary claw form a heart-shaped plate-like body in plan view having blades in the front and rear of the rotation direction, and the distal end side is curved to one side surface, and the base end part is formed. The rotary tillage device according to claim 1, wherein a mounting hole for the first or second rotary shaft is provided in the rotary tiller. 5. The rotary tiller according to claim 1, wherein a mud dropping claw is attached at a position inside the second rotary claw and facing the lower part of the center case.