JPH11137002A - Walking type power tiller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a walking type power tiller which has wheels linked to a driving axle, and is provided with a rotary working machine having a rotary working axle parallel to the driving axle at the back of the wheels, and in which the efficiency of transmission from a driving motor to the rotary working machine is increased while keeping grounding property of the wheels attributable to the weight load of the driving motor. SOLUTION: A driving motor 7 is placed above a rotary working machine 6 in such a manner that the axis line A of a power shaft 13 of the driving motor 7 crosses the axis line B of a rotary working axle 4 at almost right angles and tilts forward. The power shaft 13 is linked to the rotary working machine 6 via a clutch apparatus 8, and a gearbox 10 which is linked to the power shaft 13 of the driving motor 7 via a transmission system 68 is placed above a driving axle 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a walk-behind power cultivator, and more particularly to a drive axle, a wheel connected to the drive axle, and a rotating work shaft disposed behind the wheel and parallel to the drive axle. A rotary work machine, a prime mover for driving a drive axle and a rotary work shaft, a transmission interposed in a transmission system between the prime mover and the drive axle, and a steering handle disposed behind the rotary work machine. Things related to improvement.

[0002]

2. Description of the Related Art Such a walking type power cultivator is already known, for example, as disclosed in Japanese Utility Model Laid-Open No. 62-4658.

[0003]

In the conventional walking type power cultivator, as disclosed in the above-mentioned publication, when the body is turned during tilling, the steering handle is lifted to lift the rotary work machine. In order to facilitate the turning operation around the wheels, the prime mover is arranged immediately above the drive axle to reduce the lifting force of the steering wheel.

[0004] In addition, by disposing the prime mover directly above the axle, the wheels are effectively loaded with the weight of the prime mover itself,
The grounding properties of the wheels have been improved so that a large traction force can be obtained even during tilling work.

However, in the above-described arrangement of the prime mover in the conventional power cultivator, the transmission system for connecting the prime mover and the rotary work machine is inevitably long, and the reduction in the transmission efficiency is relatively large. Is generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to increase the efficiency of transmission to a rotary working machine while ensuring the grounding of wheels due to the heavy load of a prime mover. It is intended to provide a power cultivator.

[0007]

In order to achieve the above object, the present invention provides a drive axle, a wheel connected to the drive axle, and a rotating work shaft disposed behind the wheel and parallel to the drive axle. A rotary working machine having a driving axle and a rotating working axle, a transmission interposed in a transmission system between the driving axle and the driving axle, and a steering handle disposed behind the rotary working machine. In the walking type power cultivator, the prime mover is disposed above the rotary work machine so that the axis of the output shaft is inclined forward substantially orthogonal to the axis of the rotary work shaft, and the output shaft is connected to the rotary work machine via a clutch device. A first feature is that a transmission which is connected to a rotating work shaft by a drive and is connected to an output shaft of a prime mover via a transmission is disposed above the drive axle.

According to the first feature, since the output shaft of the internal combustion engine and the input shaft of the rear reduction gear are coaxially connected via the clutch device, their transmission systems are conventional. As a result, the transmission power is extremely short, high transmission efficiency is obtained, and the power of the internal combustion engine can be efficiently transmitted to the rotary working machine. Therefore, the tilling work can be performed with a relatively small internal combustion engine.

In addition, since the total center of gravity of the internal combustion engine and the clutch device in the forward leaning position is located at an intermediate point between the rotating work shaft and the driving axle, the weight of the internal combustion engine and the clutch device is reduced by the weight of the wheels and the wheels during the tilling operation. The load can be effectively applied to the rotary work machine, and the grounding properties of the wheels can be ensured, while the lift of the rotary work machine can be prevented.

[0010] In addition to the above-mentioned features, the present invention has a second feature in that the transmission is arranged to be inclined forward around the driving axle of the wheels.

According to the second feature, since the center of gravity of the continuously variable transmission in the forward leaning position is forward of the drive axle, the total center of gravity of the internal combustion engine and the clutch device in the forward leaning position is the rotating work shaft. In addition, the center of gravity of the walk-behind power cultivator is located near the drive axle, and the ground contact of the wheels can be further improved.

Further, the present invention has a third feature in that the transmission is a continuously variable transmission in addition to the first or second feature.

According to the third feature, by operating the continuously variable transmission, the working speed of the body can be controlled steplessly, and fine tilling work can be performed.

Further, the present invention relates to the first, second or third aspect.
In addition to the above features, the main body of the prime mover and a rear case that supports the rotating work shaft and accommodates the clutch device are integrally connected to each other to form a first frame body. The fourth feature is that a front frame body is formed by integrally connecting a front case supporting the front frame body, and the front and rear frame bodies are integrally connected via a strength member.

According to the fourth feature, a strong body can be formed without using a special frame member, and the weight of the body can be reduced, thereby making it possible to reduce the horsepower of the internal combustion engine. I do.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

First, in FIG. 1, a walking type power cultivator 1
Is a drive axle 2 extending in the left-right direction, a pair of left and right wheels 3, 3 connected to both ends thereof, and a periphery of a rotary working shaft 4 behind the wheels 3, 3 and parallel to the drive axle 2. A rotary work machine 6 having a large number of tilling claws 5 mounted thereon,
An internal combustion engine 7 (motor), a clutch device 8 and a rear reduction gear 9 disposed above the rotary working machine 6; a continuously variable transmission 10 and a front reduction gear 11 disposed above the drive axle 2; A steering handle 12 arranged behind the rotary work machine 6.

As shown in FIGS. 1 and 2, the output shaft of the internal combustion engine 7, that is, the crankshaft 13 and the input shaft 14 of the rear reduction gear 9 are coaxially connected via a clutch device 8. Then, the axis A of these shafts 13 and 14 is inclined forward substantially orthogonally to the axis B of the rotary working shaft 4, that is, the axis A
Make an acute angle α with the horizontal at the front side of the rotating work shaft 4,
The internal combustion engine 7 and the rear reduction gear 9 are arranged. At that time, the cylinder block 16 integrally provided with the crankcase 15 that supports the crankshaft 13 is disposed rearward.

The rotary working shaft 4 is supported by a rear reduction case 17 that accommodates the rear reduction gear 9 and the clutch device 8, and the upper end of the rear reduction case 17 is connected to the crankcase 15 of the internal combustion engine 7.

A small-diameter bevel gear 20 is integrally formed at the lower end of the input shaft 14 supported by the rear reduction case 17, and a large-diameter bevel gear 21 meshing with the small-diameter bevel gear 21 is fixed to the rotary working shaft 4. Thus, the rear reduction gear 9 is configured.

The clutch device 8 includes a sun gear 22 formed on the outer periphery of a lower end of a crankshaft 13 and a carrier 2 fixedly mounted on a cylindrical shaft 23 spline-coupled to an upper end of an input shaft 14.
4. a planetary gear 25 rotatably supported by the carrier 24 and meshing with the sun gear 22;
3 is provided with a planetary gear mechanism 27 including a ring gear 26 which is arranged concentrically with the planetary gear 25 and meshes with the planetary gear 25. The ring gear 26 is rotatably supported by the rear reduction case 17, and the power is intermittently connected between the crankshaft 13 and the input shaft 14 by fixing the ring gear 26 by a brake mechanism 28 or freeing it. Can be.

The brake mechanism 28 is supported by a brake drum 29 formed integrally with the ring gear 26 and a rear reduction case 17, and is expanded by a brake camshaft 30 to be in pressure contact with the inner peripheral surface of the brake drum 29. And a brake shoe 31.
Is connected to a clutch lever (not shown) attached to the steering handle 12.

When the clutch lever is not operated, the brake cam shaft 30 expands the brake shoe 31 and presses the brake shoe 31 against the inner peripheral surface of the brake drum 29 to fix the ring gear 26. Therefore, when the crankshaft 13 rotates, the planetary gear 25 driven by the sun gear 22 revolves along the ring gear 26 while rotating, and the revolution is transmitted to the input shaft 14 via the carrier 24. When the clutch lever is operated, the brake shoe 31 releases the brake drum 29 and releases the ring gear 26, so that the planetary gear 25 does not revolve and the power to the input shaft 14 is cut off.

A mounting boss 33 is integrally formed on a lower rear surface of the rear reduction case 17, and a steering handle 35) is supported on an upper end of a handle column 34 fixed to this and extending rearward and upward.

As shown in FIGS. 1 and 3, the continuously variable transmission 1
Numeral 0 includes a swash plate type hydraulic pump 38 that is driven to rotate by a pump shaft 37, and a swash plate type hydraulic motor 40 that drives to rotate a motor shaft 39 parallel to the pump shaft 37. Pump shaft 3
The motor shaft 7 and the motor shaft 39 are rotatably supported by a transmission case 41 accommodating the hydraulic pump 38 and the hydraulic motor 40 and a distribution plate 42 connected thereto. The hydraulic pump 38 is configured as a variable displacement type by allowing the pump swash plate 43 to tilt. That is, the pump swash plate 43 is supported by a swash plate holder 45 that is tiltably supported by the transmission case 41 via a trunnion shaft 44, and operates the trunnion shaft 44 to change the inclination angle of the pump swash plate 43. Thus, the capacity of the hydraulic pump 38 can be increased or decreased.

On the other hand, the hydraulic motor 40 is configured as a constant displacement type by holding the motor swash plate 46 at a fixed angle in the transmission case 41.

The hydraulic pump 38 and the hydraulic motor 40
Are communicated with each other via a high-pressure oil passage and a low-pressure oil passage formed in the distribution plate 42.

Therefore, when the hydraulic pump 38 is driven by the pump shaft 37, the hydraulic oil discharged from the hydraulic pump 38 is guided to the hydraulic motor 40 to drive it, thereby rotating the motor shaft 39. The pressure oil that has driven the hydraulic motor 40 is sucked into the hydraulic pump 38.

By the way, the pump shaft 37 and the motor shaft 39
Since the gear ratio between the two is determined by the capacity ratio between the hydraulic motor 40 and the hydraulic pump 38, the hydraulic pump 3
By increasing or decreasing the capacity of 8, the speed ratio can be controlled freely and steplessly.

The continuously variable transmission 10 is arranged to be inclined forward so that the pump shaft 37 and the motor shaft 39 are parallel to the crankshaft 13 of the internal combustion engine 7.

The drive axle 2 for the wheels 3, 3 is
The transmission case 41 is supported by a front reduction case 47 that accommodates the transmission case 1.

The front reduction gear 11 has a small-diameter bevel gear 48 integrally formed at the lower end of the motor shaft 39 and a drive axle 2.
Is fixed to an intermediate shaft 49 rotatably supported by a front reduction case 47 in parallel with the bevel gear 48.
A large-diameter bevel gear 50 meshing with the intermediate shaft 49
And a large-diameter spur gear 52 fixed to the drive axle 2 and meshing with the spur gear 51.

At the front of the front reduction case 47 of the front reduction gear 11, an article storage box 53 for storing tools, weights and the like is attached.

As shown in FIGS. 1 to 5, the crankcase 15 (motor body) and the rear reduction case 17, which are connected to each other, form a highly rigid rear frame 54.
The transmission case 41 and the front reduction case 47 joined to each other with the distribution plate 42 interposed therebetween constitute a highly rigid front frame body 55. The two frame bodies 54 and 55 are connected to each other by an upper strength member 56 and a lower strength member 57 arranged vertically. That is, both ends of the upper strength member 56 are fixed to the connection bosses 58 and 59 formed on the opposing surfaces of the crankcase 15 and the distribution plate 42 by the bolts 60 and 61 at the upper portions of the two frame bodies 54 and 55, respectively. . In the lower part of both frame bodies 54 and 55, a rear reduction case 1 is provided.
Both ends of the upper strength member 56 are fixed to connection bosses 62 and 63 formed on opposing surfaces of the front reduction case 7 and the front reduction case 47 by bolts 64 and 65, respectively.

As is apparent from FIG. 5, the internal combustion engine 7
The crankshaft 13 and the pump shaft 37 of the continuously variable transmission 10 are interconnected via a winding transmission 68. The winding transmission 68 includes a driving pulley 69 fixed to the crankshaft 13 and a driven pulley 70 fixed to the pump shaft 37.
And a belt 71 wound around these two ports 69 and 70.
It consists of

Next, the operation of this embodiment will be described.

In the tilling operation, the internal combustion engine 7 is started to give the continuously variable transmission 10 a gear ratio suitable for the tilling operation, while the brake mechanism 28 fixes the ring gear 26 to bring the clutch device 8 into the connected state. . Thus, the power of the internal combustion engine 7 is transmitted from the crankshaft 13 to the continuously variable transmission 10 via the wrapping transmission 68, passes through the hydraulic pump 38 and the hydraulic motor 40, and further transmits to the front reduction gear 11.
To the drive axle 2 to drive both wheels 3,3. The power of the internal combustion engine 7 is also transmitted from the crankshaft 13 to the rotating work shaft 4 via the clutch device 8 and the rear reduction gear 9 to drive the rotary work machine 6. That is, the power of the internal combustion engine 7 is distributed to the wheels 3, 3 and the rotary work machine 6, but the speed ratio of the continuously variable transmission 10 is controlled to a low speed side so that the wheels 3, 3 move forward at a very low speed. For
On the rotary work machine 6 side, it is necessary to rotate this at a relatively high speed, and a large load is applied. Therefore, a particularly large power is required on the rotary work machine 6 side.

Therefore, the crankshaft 13 of the internal combustion engine 7
And the input shaft 14 of the rear reduction gear 9 are coaxially connected via the clutch device 8, so that their transmission system is extremely short as compared with the conventional one, and high transmission efficiency can be obtained. Therefore, the power of the internal combustion engine 7 can be efficiently transmitted to the rotary work machine 6. Therefore, the tilling work can be performed with the relatively small internal combustion engine 7. Moreover, by operating the continuously variable transmission 10, the working speed of the machine body can be controlled steplessly, and fine tilling work can be performed.

Moreover, since the internal combustion engine 7 is arranged such that the axis A of the crankshaft 13, the clutch device 8 and the input shaft 14 is inclined forward, the total center of gravity of the internal combustion engine 7 and the clutch device 8 is rotated. Since it is located at an intermediate point between the shaft 4 and the drive axle 2, the weight of the internal combustion engine 7 and the clutch device 8 is effectively applied to the wheels 3, 3 and the rotary work machine 6 during the tilling operation, and While ensuring the grounding property of 3, the lifting of the rotary working machine 6 can be prevented.

The continuously variable transmission 10 has its pump shaft 3
7 and the motor shaft 39 are inclined forward so as to be parallel to the crankshaft 13, so that the center of gravity of the continuously variable transmission 10 is located in front of the drive axle 2, and the internal combustion engine 7 and the clutch The overall center of gravity of the device 8 is located at the intermediate point between the rotating work shaft 4 and the drive axle 2. Together, the center of gravity of the walk-behind power cultivator 1 will be near the drive axle 2, and therefore In addition, the grounding of the wheels 3, 3 can be further improved, and the body can be tilted forward with relatively light lifting force on the steering handle 12, so that the turning operation can be performed lightly.

Further, since the center of gravity of the internal combustion engine 7 and the clutch device 8 in the forward leaning position is located at an intermediate point between the rotating work shaft 4 and the drive axle 2, the internal combustion engine 7 and the clutch device 8 are operated during the tilling operation. Weight is added to the rotary work machine 6 moderately, and a desired plowing depth can be easily obtained while reducing the pushing force of the operator on the steering handle 12.

In such a cultivator 1, a highly rigid rear frame 54 composed of the crankcase 15 and the rear reduction case 17 of the internal combustion engine 7, and a highly rigid front composed of the transmission case 41 and the front reduction case 47. Since the frame body 55 is connected to each other by the upper strength member 56 and the lower strength member 57 arranged vertically, a strong body can be configured without using a special frame member, and This contributes to weight reduction, thereby enabling the internal combustion engine 7 to have small horsepower.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the present invention. For example, instead of the internal combustion engine 7,
An electric motor can also be used. In addition, the winding transmission 6
Instead of 8, a gear or other transmission may be used.

[0044]

As described above, according to the first aspect of the present invention, the prime mover is tilted forward of the rotary working shaft so that the axis of the output shaft thereof is inclined substantially perpendicular to the axis of the rotary working shaft. The output shaft of the engine is connected to the rotary work machine via a clutch device, and the transmission connected to the output shaft of the prime mover via a transmission device is arranged above the drive axle. The transmission system between the shaft and the input shaft of the rear reduction gear is extremely short as compared with the conventional one, so that high transmission efficiency can be obtained and the power of the internal combustion engine can be efficiently transmitted to the rotary work machine.

Further, since the total center of gravity of the internal combustion engine and the clutch device in the forward leaning position is located at an intermediate point between the rotating work shaft and the drive axle, the weight of the internal combustion engine and the clutch device is reduced by the weight of the wheels and the wheel during the tilling operation. The load can be effectively applied to the rotary work machine, and the grounding properties of the wheels can be ensured, while the lift of the rotary work machine can be prevented.

According to the second feature of the present invention, since the transmission is arranged to be inclined forward around the drive axle of the wheels, the center of gravity of the continuously variable transmission in the forwardly inclined posture comes forward of the drive axle. Yes,
The total center of gravity of the internal combustion engine and the clutch device in the forward leaning position is located at the intermediate point between the rotating work shaft and the drive axle. Together, the center of gravity of the walking type power cultivator is located near the drive axle. This makes it possible to further improve the contact property of the wheel.

Further, according to the third feature of the present invention, since the transmission is a continuously variable transmission, by operating the continuously variable transmission, the working speed of the machine body is controlled steplessly, thereby providing a fine-grained operation. Tilling work can be performed.

Further, according to a fourth aspect of the present invention,
A main body of the prime mover and a rear case supporting the rotating work shaft and accommodating the clutch device are integrally connected to form a first frame body, while a transmission case of a transmission and a front case supporting wheels. To form a front frame body, and the front and rear frame bodies are integrally connected via a strength member, so that a strong body can be used without using a special frame member. It can be constructed and contributes to the weight reduction of the fuselage, thereby enabling a small horsepower of the internal combustion engine.

[Brief description of the drawings]

FIG. 1 is a side view of a walking type power cultivator according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of a rear half of the tiller.

FIG. 3 is an enlarged side view of the first half of the tiller.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

[Explanation of symbols]

 1 ··· Walk-type power cultivator 2 ····· Drive axle 3 ··· Wheels 4 ··· Rotating work shaft 6 ··· Rotary work machine 7 ··· Motor (internal combustion engine) 8 clutch device 9 rear speed reducer 10 transmission (stepless transmission) 12 steering handle 13 motor Output shaft (crankshaft) 15 ··· Motor body (crankcase) 17 ··· Rear case (rear reduction case) 41 ··· Transmission case 47 ··· Front case (front reduction case) 54, rear frame 55, front frame 56, strength member 57, strength member 68, transmission (wrapping transmission) A・ Axis line of the output shaft of the prime mover B ・ ・ ・ ・ ・ Axis line of the rotating work shaft

Claims (4)

[Claims] 1. A drive axle (2), a wheel (3) connected to the drive axle (2), and a rotating working shaft (3) arranged behind the wheel (3) in parallel with the drive axle (2). 4) a rotary work machine (6), a drive axle (2) and a prime mover (7) for driving a rotary work shaft (4), and a transmission system between the prime mover (7) and the drive axle (2). Transmission (1
0), and a walking-type power cultivator equipped with a steering handle (12) arranged behind the rotary work machine (6), wherein the prime mover (7) has an axis (A) of an output shaft (13). The rotary work machine (6) is disposed above the rotary work machine (6) so as to tilt forward substantially orthogonal to the axis (B) of the rotary work shaft (4), and its output shaft (13) is rotated via a clutch device (8). The transmission (10) connected to the work machine (6) and connected to the output shaft (13) of the prime mover (7) via the transmission (68) is arranged above the drive axle (2). Characterized by a walking power cultivator. 2. The power cultivator according to claim 1, wherein the transmission (10) is inclined forward around a drive axle (2) of the wheels (3). 3. The walking type power cultivator according to claim 1, wherein the transmission (10) is a continuously variable transmission. 4. The rear case (17) according to claim 1, 2 or 3, which supports a main body (15) of a motor (7) and a rotating work shaft (4) and houses a clutch device (8). ) And the rear frame body (54).
, A transmission case (41) of the transmission (10) and a front case (4) supporting the drive axle (2).
7) are integrally connected to form a front frame body (55), and the front and rear frame bodies (54, 55) are integrally connected via strength members (56, 57). A walking-type power cultivator characterized by that.