JP2003204701A - Front rotary type working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front rotary type working machine with which interference of a transmission case with soil tilled by a rotary working part is controlled so that finishing properties of tilling are secured and traveling resistance is controlled so as to reduce the load of an operator. <P>SOLUTION: This front rotary type working machine is a walking type power tiller with which the transmission case 58 is arranged below an engine 20, output shafts 53 and 57 are projected from the front part and the rear part of the transmission case, respectively, traveling wheels 11 are driven by the rear output shaft 57 and a rotary working part 120 is driven by the front output shaft 53. The lower side 58a of the transmission case 58 is flattened and is made approximately in parallel with the ground surface. The lower side of the transmission case has a shape of being lower in the back. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an improvement of a front rotary type working machine.

[0002]

2. Description of the Related Art A general walk-behind work machine is a cultivator that is cultivated by rotation of a cultivating claw provided on a cultivating shaft and further travels by the cultivating claw, and is called a front tine type working machine. On the other hand, in recent years, a walk-type cultivator in which a cultivating claw is arranged in front of a vehicle body having traveling wheels, that is, a so-called front rotary working machine has been developed. The front rotary type working machine is provided with a plowing claw in front of the machine body, so that it is easy to cultivate in a headland, and the operator's eyes are on the front, so the workability is good, and it is attracting attention.

A "headland" is a kind of partial vacant land that can be used to temporarily suspend work such as turning at both ends when performing work in a field by reciprocating parallel to one side. That is.

As this type of front rotary working machine, for example, Japanese Patent No. 3015821 "Agricultural Working Machine"
(Hereinafter referred to as "conventional technology") is known. This conventional technique is a downcut-type tiller that rotates a tillage claw from the upper front in the traveling direction toward the ground, and is mainly used for tillage. As an example of a front rotary type working machine, an outline of the above-mentioned conventional technique will be described with reference to FIG.

FIG. 14 is a schematic diagram of a conventional front rotary type working machine, which is shown in FIG. 1 of Japanese Patent No. 3015821.
2, 5, 12, and 13 are collectively reproduced as a side view. The reference numerals were reassigned.

A conventional front rotary working machine 200
Is provided with a transmission case 203 under a machine body 202 to which an engine 201 is attached. The transmission case 203 is provided in the rear transmission case 204 and the front rotary case 20.
5 is an integrally molded product, and a pair of left and right running wheels 207, 207 are attached to an axle 206 extending from the rear of the mission case 204.
The rotary intermediate shaft 208 is attached to the front of the transmission case 204, and the tilling claw 210 ... (... indicates a plurality of numbers. The same applies hereinafter) to the cultivating shaft 209 that extends from the front of the rotary case 205. Attach the rotary case 2
05, a walking cultivator in which a chain 213 is hung between a drive sprocket 211 of the rotary side intermediate shaft 208 and a driven sprocket 212 of the cultivating shaft 209.

The engine 201 is a horizontal engine having an output shaft 214 protruding laterally. A drive pulley 215 attached to the output shaft 214 and a driven pulley 2 attached to an input shaft 216 protruding from the side of the transmission case 204.
The belt 218 is hung between 17 and the engine 2
01 power can be transmitted to the mission side. Therefore, the power of the engine 201 drives the pair of left and right traveling wheels 207, 207 via the axle 206, and at the same time, the rotary side intermediate shaft 208, the chain 213 and the tiller shaft 209.
It is possible to drive the tilling claws 210 ...

Further, a front rotary type working machine 200
Is a plurality of tilling claws 210 ... Arranged in four rows in the width direction of the machine body 202 (front and back directions in the figure). By rotating all the tillage claws 210 ... In one direction together with the tiller shaft 209, it is possible to cultivate. In addition, 21
9 is a tension roller as a main clutch, 220
Is the handlebar.

[0009]

In the above conventional front rotary working machine 200, the transmission case 203 has a rear transmission case 204 and a front rotary case 205 which are substantially separated from each other when viewed from the side. It is a structure that is combined in a V shape (upside down V shape). That is, the rear mission case 204 is tilted rearward and the front rotary case 205 is tilted frontward.

When the soil Gr21 is cultivated by a tilling claw (corresponding to a rotary working portion) 210 ..., the cultivated soil Gr22 rises. The raised soil Gr22 is
It can hit the bottom of the mission case 204, which leans backward. The greater the depth of tillage by the tilling claws 210, the lower the ground height of the mission case 204, and this tendency becomes more noticeable. If the cultivated soil Gr22 is scraped off at the bottom of the mission case 204, it cannot be finished flat. There is room for improvement because the finishing performance of tillage is poor.

Furthermore, since the mission case 204 is inclined rearward and downward, it can be an obstacle to the cultivated soil Gr22. When it becomes an obstacle, the cultivated soil Gr22 may be accumulated in front of it. Accumulated soil Gr
When the mission case 204 gets on the vehicle 23, it becomes a running resistance when the front rotary working machine 200 is moved forward. The running resistance is unbalanced, and if the running resistance is large, the burden on the operator becomes large to maintain the straight running performance of the front rotary working machine 200, and there is room for improvement.

Therefore, an object of the present invention is to suppress the interference of the transmission case with the soil cultivated in the rotary working part in the front rotary type working machine in which the tilling claw is arranged in front of the machine body having the running wheels, It is an object of the present invention to provide a technique capable of ensuring plowing performance and suppressing traveling resistance to reduce the burden on workers.

[0013]

In order to achieve the above object, a first aspect of the present invention is to dispose a transmission case below an engine, and output an output shaft from a front portion and a rear portion of the transmission case, and output an output shaft at the rear portion. In the front rotary type working machine in which the traveling wheels are driven by the front drive shaft and the rotary working section is driven by the front output shaft, the lower surface of the transmission case is made flat and substantially parallel to the ground. .

Since the lower surface of the transmission case is made flat and substantially parallel to the ground, even if the soil cultivated in the rotary working portion rises, it is possible to suppress the interference of the transmission case with the raised soil. Therefore, there is no need to worry about scraping the cultivated soil on the lower surface of the transmission case. As a result, tillability can be secured. Furthermore, there is no concern that cultivated soil will accumulate in front of the transmission case. Therefore, it is possible to suppress the transmission case from climbing up on the accumulated soil, so that the running resistance of the front rotary working machine can be suppressed. As a result, since there is no unbalanced running resistance, it is possible to reduce the burden on the operator in maintaining the straight running performance of the front rotary working machine.

A second aspect of the present invention is characterized in that the lower surface of the transmission case has a rearwardly downward shape. Since the lower surface of the transmission case is flat and has a rearward descending shape, the cultivated soil can be leveled by the lower surface of the transmission case. Therefore, the tillability can be improved. Moreover, since the lower surface of the transmission case is substantially parallel to the ground and has a rearward descending shape, even if the transmission case comes into contact with the soil that has been cultivated and risen, it is possible to easily get over the soil.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, "before", "after",
“Left”, “right”, “upper” and “lower” follow the direction seen from the operator of the walk-behind work machine, Fr is the front side, Rr is the rear side, L is the left side, R is the right side, CL is the body The width center (working machine center, working machine center) is shown. Further, the drawings are to be viewed in the direction of reference numerals.

FIG. 1 is a left side view of a front rotary working machine according to the present invention. The front rotary working machine 10 has left and right traveling wheels 11 (only the left side is shown in this figure).
It is a small walking type self-propelled cultivator in which a rotary working unit 120 is arranged in front of a transmission case 58 provided with.

More specifically, the front rotary type working machine 10
(Hereinafter, simply referred to as “working machine 10”) is provided with traveling wheels 11 in a transmission case 58 as a machine body,
A rotary working unit 120 is provided in front of the transmission case 58, and the traveling wheel 11 and the rotary working unit 120 are driven by the engine 20 provided in the transmission case 58.
It is a walk-behind work machine that drives.

More specifically, this figure shows the engine 2
A transmission case 58 is disposed below 0 through the main clutch 30, and output shafts 53 and 57 are respectively output from the front and rear portions of the transmission case 58, and a rotary shaft is provided at the front output shaft (rotary side intermediate shaft) 53. It is shown that the working unit 120 is driven and the traveling wheel 11 is driven by the rear output shaft (axle) 57. In this way, the traveling wheels 1 are attached to the rear of the transmission case 58.
1 and the transmission case 58
The front rotary working part 120 can be arranged.

The engine 20 as a power source is a vertical engine in which an output shaft (crankshaft) 21 is oriented substantially vertically, a cylinder 22 is extended substantially horizontally forward, and an oil tank 23 is provided at a rear portion.

The working machine 10 has an operation handle 12 extending rearward and upward from a rear portion of the clutch case 34 of the main clutch 30, and the operation handle 12 is provided with a clutch lever 13. The clutch lever 13 is a clutch lever that operates the main clutch 30. In the figure, 14 is a cover for preventing the scattering of earth and sand.

FIG. 2 is a sectional view of the engine, main clutch and transmission case according to the present invention.
The output shaft 21 of the engine 20 is projected downward,
3 is a left side view of a configuration in which a transmission 50 is connected to a lower end of the transmission via a main clutch 30.

The upper end of the clutch case 34 is bolted to the lower end of the body 25 of the engine 20 so that the clutch case 34
By coupling the transmission case 58 of the transmission 50 to the lower end of the
4 and the transmission case 58 play the role of an airframe.

FIG. 3 is a sectional view of the main clutch according to the present invention and corresponds to FIG. 2 described above. Main clutch 30
Is a sun gear 31 attached to the output shaft 21 of the engine 20.
A planetary gear assembly 32 to be combined with the sun gear 31, an internal gear 33 to be combined with the planetary gear assembly 32, and a clutch case 34 for housing the sun gear 31, the planetary gear assembly 32 and the internal gear 33. , These internal gears 33
, And a clutch case 34, and a plurality of balls 35, ... (... indicates a plurality, the same applies hereinafter), and a brake 36 for locking / unlocking the internal gear 33.

The planetary gear assembly 32 includes a plurality of planetary gears 37 ... Which mesh with the sun gear 31 and the internal gear 33.
And a planetary frame 38 that rotatably supports these planetary gears 37. At the center of the planetary frame 38, a joint 3 for spline coupling the input shaft 51 of the transmission 50.
9 is provided. The internal gear 33 includes a tooth portion 33a that meshes with the planetary gears 37, and a cylindrical portion 3 that applies the brake 36.
3b and. The cylindrical portion 33b serves as a brake drum. The balls 35 ... Are supporting members that support the internal gear 33.

FIG. 4 is a plan view of the main clutch according to the present invention. The brake 36 of the main clutch 30 is
Anchor pin 41 attached to clutch case 34 and a pair of brake shoes 42, 4 supported by anchor pin 41
2, operating cam 43 for expanding the diameter of the brake shoes 42, 42
And a lever 44 connected to the actuating cam 43, and a lever 44
And a cable 46 connected thereto via a tension spring 45.

The brake shoes 42, 42 are provided with return springs 47, 47 that spring to attract each other, and brake pads 48, 48 that lock the internal gear 33. The cable 46 is connected to the clutch lever 13 (see FIG. 1).

Next, the operation of the main clutch 30 will be described with reference to FIG. In the state shown in this figure, since the brake 36 is opened, the internal gear 33 is rotatable. When the sun gear 31 is rotated by the output shaft 21 of the engine 20, the planet gears 37 ... At this time, since the internal gear 33 is in the free state, it rotates. As a result, the planet frame 38 does not rotate. Therefore, the main clutch 30 maintains a so-called clutch-off state in which the power of the engine 20 is not transmitted from the output shaft 21 to the input shaft 51 of the transmission 50.

After that, the clutch lever 13 (see FIG. 1)
The brake 36 is turned on by operating the and pulling the cable 46. The internal gear 33 cannot rotate. Sun gear 31
When is rotated, the planet gears 37 ... At this time, the internal gear 33 does not rotate because it is in the locked state.
As a result, the planet frame 38 rotates. Therefore, the main clutch 30 switches to a so-called clutch-on state in which the power of the engine 20 is transmitted from the output shaft 21 to the input shaft 51 of the transmission 50. When the clutch lever 13 is released, the main clutch 30 automatically returns to the original clutch-off state.

Here, returning to FIG. 2, the description will be continued. The input shaft 51 of the transmission 50 is concentric with the output shaft 21 of the engine 20. By engaging the drive bevel gear 52 provided at the lower end of the input shaft 51 and the first driven bevel gear 54 provided on the rotary-side intermediate shaft 53, power can be transmitted from the input shaft 51 to the rotary-side intermediate shaft 53.

In the transmission 50, the rotary-side intermediate shaft 53, the first intermediate shaft 55, the second intermediate shaft 56, and the axle 57 are arranged horizontally in this order from the front to the rear in the machine width direction. 55 to 57 are connected by a gear mechanism. Therefore, the transmission 50
The transmission case 58 can be set to be long in the front-rear direction and narrow in the vehicle width direction (front and back directions in this figure). Moreover, the height of the transmission case 58 can be reduced (thinned).

The lower surface 58 of the transmission case 58
a is flat and substantially parallel to the ground. Specifically, when the center line Pe of the output shaft 21 of the engine 20 is a vertical line, the lower surface 58a is substantially parallel to a horizontal line Ho that is perpendicular to the vertical line Pe. The horizon Ho is parallel to the ground. Further, the lower surface 58 of the transmission case 58
“A” has a rearward-falling shape. The inclination angle θ1 of the lower surface 58a with respect to the horizontal line Ho is an extremely gentle angle of about 5 °.

In such a working machine 10, the rotary intermediate shaft 53 and the rotary working part 120 (see FIG. 1) are connected by a transmission shaft 71, and the transmission shaft 71 is surrounded by a cylindrical case 73. The cylindrical case 73 is attached to the transmission case 58.

Specifically, the first driven bevel gear 54 provided on the rotary-side intermediate shaft 53 and the second driven bevel gear 72 provided on the transmission shaft 71 are meshed with each other, and the transmission shaft 71 is moved downward toward the tiller shaft 100. The transmission shaft 71 is rotatably supported by the cylindrical case 73 by bearings 74 and 75, and the base end of the cylindrical case 73 is bolted to the mounting seat 58b of the transmission case 58. The inclination angle θ2 of the transmission shaft 71 and the cylindrical case 73 with respect to the center line Pe of the output shaft 21.
Is about 60 °.

Since the thin transmission case 58 is adopted as described above, the height from the tilling shaft 100 to the lower surface 58a of the transmission case 58 is relatively large. Therefore, the ground clearance of the lower surface 58a is higher than in the conventional case. The cylindrical case 73 is formed of a cylinder and has a storage case 94 integrally formed at the front end. The storage case 94 is
It is a split case that can be removed with the center of the cultivating shaft 100 as a reference.

As is apparent from the above description, the vertical engine 2 is provided between the rear axle 57 and the front tillage shaft 100.
0 is arranged and the center of gravity of the working machine 10 is moved forward, so that a part of the weight of the engine 20 is removed.
(See FIG. 1). Further, the output shaft 21 of the engine 20 and the input shaft 51 of the transmission 50 are arranged vertically and concentrically. Conventionally, a horizontal engine having an output shaft protruding laterally is adopted, and a belt is attached to the output shaft of the engine and the input shaft of the transmission. On the other hand, according to the present invention, the engine 20 can be brought close to the upper surface of the transmission case 58. Therefore, the center of gravity of the working machine 10 can be lowered by lowering the height of the engine 20.

FIG. 5 is a sectional view taken along line 5-5 of FIG. 2, showing the transmission case 58 in a partial cross section. A first drive spur gear 61 and a second drive spur gear 62 are provided on the rotary side intermediate shaft 53, and a first driven spur gear 63, a second driven spur gear 64 and the dog clutch 6 are provided on the first intermediate shaft 55.
5, the dog clutch 65 is switched to release the power transmission from the rotary side intermediate shaft 53 to the axle 57 via the first intermediate shaft 55, and the rotary intermediate shaft 53 to the axle via the first intermediate shaft 55. It is possible to switch to high speed or low speed power transmission to 57. In the figure, 67 is a gear shift lever.

This figure shows a transmission case 58.
Indicates that it is long in the front-rear direction and narrow in the vehicle width direction. Since the width of the transmission case 58 is narrow, the running wheels 11 shown by the imaginary line are brought close to the center CL of the body width or the center C of the body width C
It can be separated from L to the outside.

FIG. 6 is a sectional view taken along line 6-6 of FIG. 2, and is a view corresponding to FIG. 5, around the tilling power transmitting mechanism 80 for transmitting power from the transmission side to the tilling shaft 100. Shown in cross section. The tiller shaft 100 extends horizontally in the machine width direction and includes a main tiller shaft 84, a left hollow shaft 85 and a right hollow shaft 87.

The cultivating power transmission mechanism 80 is used for the engine 20.
(See FIG. 2) The transmission shaft 71 for transmitting the power of the power transmission toward the tiller shaft 100, the first bevel gear 81 provided at the tip of the transmission shaft 71, and the first bevel gear 81 meshed with the first bevel gear 81 and arranged in parallel with each other. 2 bevel gears 82 and 3rd
A bevel gear 83, a main cultivating shaft 84 integrally provided on the second bevel gear 82, a hollow left hollow shaft 85 integrally rotatably fitted on the main cultivating shaft 84 and relatively provided on the third bevel gear 83. , The third bevel gear 8 is attached to the left hollow shaft 85.
3 and a left gear 86 provided separately from the main gear shaft 8 so that the second and third bevel gears 82 and 83 are sandwiched between the left gear 86 and the left gear 86.
4, a right hollow shaft 87 that is relatively rotatably fitted, a right gear 88 provided on the right hollow shaft 87, and left and right gears 86, 88 for mechanically connecting the right gear 88 to the left gear 86. A counter shaft 93 with a gear (a counter left gear 91 and a counter right gear 92) passed between them, and at least a transmission shaft 7
The first, second, third and third bevel gears 81 to 83, the left and right gears 86 and 88, and a storage case 94 that collectively stores the counter shaft 93.

The main cultivating shaft 84 is a long solid shaft extending in the width direction of the machine body, and is a shaft having reversible left sleeve 95 and reversible right sleeve 96 removably attached to both left and right ends by bolting or the like. The left hollow shaft 85 is a shaft having a forward rotation left sleeve 97 integrally attached to the left end by a key or the like. The right hollow shaft 87 is a shaft in which a forward rotation right sleeve 98 is integrally attached to the right end by a key or the like. These sleeves 95 to 98 are hollow shafts. In the figure, 111 to 113 are bearings, and 114 is a thrust bearing.

FIG. 7 is a front view of a front rotary type working machine according to the present invention, in which the engine 2 is provided in the width center CL of the machine body.
0, clutch case 34, transmission case 5
8 and the cylindrical case 73 are arranged, and the clutch case 34 and the transmission case 58 are housed within the width W1 of the engine 20.

The rotary working unit 120 is a combination of a plurality of tillers. Plural tilling claws are forward claws 121 ...
, 122 ... (namely, the first forward rotation claw 121 ... And the second forward rotation claw 122 ...) And the reverse rotation claw 123. Hereinafter, when the term "cultivating claw" is used, the first forward rotating claw 121 ...
The second forward rotation claws 122 and the reverse rotation claws 123 are collectively referred to. Further, when the normal rotation claws 121 ... 122 are referred to, the first normal rotation claws 121 ... And the second normal rotation claws 122 ...

The rotary working unit 120 arranges a plurality of forward rotation pawls 121 ... 122 among the plowing pawls in the center of the width of the transmission case 58 as a machine body, and the reverse rotation pawls 123 ... It is characterized in that a plurality of claws 121, 122, 122 are arranged outside in the width direction of the machine.

Specifically, the rotary working parts 120 are arranged in four rows in the machine width direction, and the forward rotation pawls 121 are attached to the attachment plate 97a of the left inner forward rotation left sleeve 97.
, 122 ... group 131 (first claw group 131), group 132 (first claw group 121 (first claw group) of the forward rotation claws 121 ... 2 claw group 13
2), a mounting plate 95a for the left outer reverse rotation sleeve 95
Group 133 of reversing claws 123 ...
3) and a group 134 (fourth claw group 134) of the reverse claws 123 ... Attached to the mounting plate 96a of the right outer reverse sleeve 96.

The left and right running wheels 11, 11 are arranged behind the plurality of reverse rotation claws 123. That is, the third claw group 13
The left running wheel 11 is arranged behind 3 and the right running wheel 11 is arranged behind the fourth claw group 134.

As is clear from the above description, a vertical engine is adopted as the engine 20 and its output shaft 21
By disposing (see FIG. 2) in the width center CL of the machine body, the weight balance in the width direction of the working machine 10 can be enhanced. Moreover, since the engine 20 is located in the width center CL, the running wheels 11, 11 can be brought closer to the body width center CL by disposing the left and right running wheels 11, 11 so as to be close to the engine 20.

FIGS. 8A and 8B are configuration diagrams of the rotary working unit according to the present invention, and FIG. 8A is a rotary working unit 12 of the present invention.
0 is an exploded view, and (b) is a view from the arrow b of (a). In addition,
For ease of understanding, the mounting plates 95a, 96a, 97a, 98a and the cultivating shaft 100 shown in FIGS. 6 and 7 are omitted.

The forward-rotating claws 121 and 122 are directed to the direction R from the upper front of the traveling direction Ru of the working machine 10 (see FIG. 7) to the ground.
1, a claw that rotates in the forward rotation direction R1. The reverse rotation claw 123 has a direction R that extends from the upper rear of the traveling direction Ru to the ground.
2, a claw that rotates in the reverse direction R2.

The rotary working unit 120 includes a plurality of forward rotation pawls 1.
21 ..., 122 ... are arranged in the same phase in a side view, and a plurality of reverse claws 123 ... are arranged in the same phase in a side view. This will be described in detail below.

The first and second claw groups 131, 132 have four forward claws 121, ..., 1 in total with respect to the center Pf of the tilling shaft.
The bases of 22 ... The third and fourth claw groups 133 and 134 have a center P of the tilling axis.
Based on f, the respective bases of the four reverse claws 123 ...

In this figure, the first claw group 131 is a first claw group extending in the traveling direction Ru of the working machine 10 (that is, in the upper front direction).
A forward rotation claw 121, a second forward rotation claw 122 extending rearward and upward,
It is composed of a combination of a first forward rotation pawl 121 extending rearward and downward and a second forward rotation pawl 122 extending rearward and forward. Two first forward claws 1
Reference numerals 21 and 121 denote flat nails whose tip portions are curved toward the second nail group 132 side and are also curved in the reverse direction R2. Two
The second forward rotation claws 122, 122 each have a tip portion of the third claw group 1
It is a claw which is curved toward 33 and is also curved in the reverse direction R2. The second claw group 132 is a group formed symmetrically with the first claw group 131.

The third claw group 133 is arranged such that the phase thereof is shifted by about 45 ° in the forward rotation direction R1 with respect to the first claw group 131, and four reverse claws 123 extending in the front-rear direction and in the vertical direction.
It consists of a combination of ... All the reverse rotation claws 123 ... Are curved in the forward rotation direction R1 while curving their tips toward the first claw group 131 side.
It is also a curved nail. The fourth claw group 134 is the third
This is a group formed symmetrically with the claw group 133. In addition, as a matter of course, the phase of each claw group 131 to 134 changes according to the rotation of the tiller shaft 100 (see FIG. 7).

Next, the operation of the tilling power transmission mechanism 80 having the above structure will be described with reference to FIGS. 2, 7 and 9 to 11. In FIG. 2, the power of the engine 20 is the output shaft 2
1 → Main clutch 30 → Input shaft 51 of transmission 50 → Drive bevel gear 52 → First driven bevel gear 5
It is transmitted to the transmission shaft 71 through the path of 4 → second driven bevel gear 72.

FIG. 9 is an operation diagram (No. 1) of the tilling power transmission mechanism according to the present invention. In addition, the transmission shaft 71 in the engine
When the engine is rotated in the rotation direction R0, the engine power is transmitted from the transmission shaft 71 to the first bevel gear 81 → the second bevel gear 82.
→ It is transmitted to the left sleeve for reverse rotation 95 and the right sleeve for reverse rotation 96 through the path of the main tilling shaft 84. As a result, the reverse left / right sleeves 95 and 96 rotate in the reverse direction R2.

FIG. 10 is an operation diagram (part 2) of the tilling power transmission mechanism according to the present invention. On the other hand, the transmission shaft 71
When the engine is rotated in the rotation direction R0, the engine power is transmitted from the transmission shaft 71 to the first bevel gear 81 → the third bevel gear 83.
→ It is also transmitted to the forward rotation left sleeve 97 through the path of the left hollow shaft 85. As a result, the forward rotation left sleeve 97 rotates in the forward rotation direction R1.

FIG. 11 is an operation diagram (No. 3) of the tilling power transmission mechanism according to the present invention. Furthermore, when the transmission shaft 71 is rotated in the rotational direction R0 by the engine, the engine power is transmitted from the transmission shaft 71 to the first bevel gear 81 → the third bevel gear 83 → the left hollow shaft 85 → the left gear 86 → the counter left gear. 91 → counter shaft 93 → counter right gear 92 → right gear 88 → right hollow shaft 87 is also transmitted to the forward rotation right sleeve 98. As a result, the forward rotation right sleeve 98 is rotated in the forward rotation direction R.
Turn to 1.

Therefore, as shown in FIG. 7, the left and right sleeves 95, 96 for reverse rotation are transmitted while transmitting the power of the engine 20.
(Reverse rotation pawl 123 attached to the main cultivating shaft 84 in FIG. 6) and forward rotation pawl 121 attached to the left and right sleeves 97 and 98 for normal rotation (left and right hollow shafts 85 and 87 in FIG. 6).・ 、 122 ・ ・ ・
Can be rotated opposite to each other for cultivating work.

FIG. 12 is an operation diagram (No. 1) of the front rotary type working machine according to the present invention.
The case where the depth of cultivation by 0 is medium is shown. When the soil Gr11 is cultivated by the rotary working unit 120, the cultivated soil Gr12 rises. On the other hand, the present invention employs a thin transmission case 58. The lower surface 58a of the transmission case 58 is flat and substantially parallel to the ground surface Gr1. Therefore, even if the soil depth of cultivation is medium and the soil Gr12 cultivated by the rotary working unit 120 rises, the raised soil Gr12 has a lower surface 58a.
Does not hit

FIG. 13 is an operational view (No. 2) of the front rotary type working machine according to the present invention.
The case where the depth of cultivation by 0 is large is shown. Even when the plowing depth is large, the interference of the transmission case 58 with the raised soil Gr12 can be suppressed. Therefore, there is no concern that the cultivated soil Gr12 will be scraped off by the lower surface (bottom) 58a of the transmission case 58. As a result, tillability can be secured.

Furthermore, the transmission case 58
Since the lower surface 58a is flat and substantially parallel to the ground surface Gr1, there is no fear that the lower surface 58a will be an obstacle to the cultivated soil Gr12. Therefore, cultivated soil Gr1
There is no concern that 2 will accumulate in front of the transmission case 58. Therefore, it is possible to prevent the transmission case 58 from climbing up on the accumulated soil.
The running resistance of 0 can be suppressed. As a result, since there is no unbalanced running resistance, it is possible to reduce the burden on the operator in maintaining the straight running performance of the working machine 10.

Furthermore, the transmission case 5
The lower surface 58a of No. 8 is flat and has a rearward descending shape. Plowed soil Gr12, transmission case 58
Can be leveled by the lower surface 58a. Therefore, the tillability can be improved. Moreover, since the lower surface 58a of the transmission case 58 is substantially parallel to the ground Gr1 and has a rearward descending shape, even if the transmission case 58 comes into contact with the soil Gr12 that has been cultivated and rises, the soil Gr12 can be easily overcome. .

[0063]

The present invention has the following effects due to the above configuration. According to the first aspect of the present invention, the lower surface of the transmission case is made flat and substantially parallel to the ground. Therefore, even if the soil cultivated in the rotary working portion rises, the interference of the transmission case with the raised soil can be suppressed. . Therefore, there is no need to worry about scraping the cultivated soil on the lower surface of the transmission case. As a result, tillability can be secured. Furthermore, there is no concern that cultivated soil will accumulate in front of the transmission case. Therefore, it is possible to suppress the transmission case from climbing up on the accumulated soil, so that the running resistance of the front rotary working machine can be suppressed. As a result, since there is no unbalanced running resistance, it is possible to reduce the burden on the operator in maintaining the straight running performance of the front rotary working machine.

According to the second aspect of the present invention, since the lower surface of the transmission case is flat and has a rearward descending shape, the cultivated soil can be leveled by the lower surface of the transmission case. Therefore, the tillability can be improved. Moreover, since the lower surface of the transmission case is substantially parallel to the ground and has a rearward descending shape, even if the transmission case comes into contact with the soil that has been cultivated and risen, it is possible to easily get over the soil.

[Brief description of drawings]

FIG. 1 is a left side view of a front rotary working machine according to the present invention.

FIG. 2 is a sectional view around the engine, main clutch, and transmission case according to the present invention.

FIG. 3 is a sectional view of a main clutch according to the present invention.

FIG. 4 is a plan view of a main clutch according to the present invention.

5 is a sectional view taken along line 5-5 of FIG.

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 is a front view of a front rotary working machine according to the present invention.

FIG. 8 is a configuration diagram of a rotary working unit according to the present invention.

FIG. 9 is an operation diagram of the tilling power transmission mechanism according to the present invention (No. 1)

FIG. 10 is an operation diagram (part 2) of the tilling power transmission mechanism according to the present invention.

FIG. 11 is an operation diagram of a tilling power transmission mechanism according to the present invention (part 3)

FIG. 12 is an operation diagram of a front rotary working machine according to the present invention (No. 1)

FIG. 13 is an operation diagram (part 2) of the front rotary working machine according to the present invention.

FIG. 14 is a schematic diagram of a conventional front rotary working machine.

[Explanation of symbols]

10 ... Front rotary type working machine, 11 ... Running wheel, 20
... engine, 53 ... front output shaft (rotary side intermediate shaft), 57 ... rear output shaft (axle), 58 ... transmission case, 58a ... transmission case bottom surface, 120 ... rotary working part, 121, 122, 12
3 ... Tilling claws (first and second forward rotating claws, reversing claws), Gr1 ... Ground, Gr11 ... Soil, Gr12 ... Soil cultivated and raised.

Claims (2)

[Claims] 1. A transmission case is arranged below an engine, output shafts are respectively output from a front portion and a rear portion of the transmission case, driving wheels are driven by the rear output shaft, and a rotary working portion is driven by the front output shaft. In the front rotary type working machine, the front surface of the transmission case is made flat and is substantially parallel to the ground. 2. The front rotary working machine according to claim 1, wherein a lower surface of the transmission case has a rearward-lowering shape.