JP3101500B2 - Transmission for walk-behind work machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for constructing a transmission of a walk-behind work machine such as a walk-behind cultivator or a walk-behind mower as a rational structure suitable for the working form.

[0002]

2. Description of the Related Art Walking-type working machines include a one-wheel type having one drive wheel at the left and right centers of the fuselage and a two-wheel type having left and right wheels equally distributed with respect to the left and right centers of the fuselage. is there.
As the former, there are those disclosed in JP-A-2-169326 and JP-A-6-153604,
The latter is disclosed in JP-A-6-121601.

[0003]

In the one-wheel type vehicle, the traveling output shaft and the PTO output shaft of the transmission case are provided on the same left and right sides as in the above two publications. In either case, the transmission case is interposed so that the wheels and the PTO transmission case are arranged at the center in the left and right directions. In such a structure, the PTO transmission case is arranged at the center of the body in the left and right direction. However, if the transmission case is deviated left and right, it is disadvantageous in terms of weight balance. Therefore, the problem is solved by providing the PTO auxiliary transmission case. However, the PTO auxiliary transmission case, which is not indispensable from the point of view of the transmission function, is redundant, and it seems that the transmission efficiency is reduced and the structure of the transmission system is complicated. An object of the present invention is to simplify the structure by reviewing the structure of the transmission so that a one-wheel drive walking work machine can be reasonably configured without using a PTO auxiliary transmission case.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a PTO transmission system having an input shaft and a PTO output shaft and a traveling transmission system having a traveling output shaft, which is divided into right and left. The gear transmission is housed in the casing with the gears arranged, and the input shaft and travel
Between the power shaft and the gears constituting the PTO transmission system and the traveling transmission
PTO with a transmission shaft fitted with gears constituting the system
A PTO transmission case for driving the work equipment is mounted on the output shaft, a traveling transmission case for driving the wheels is mounted on the traveling output shaft, and an input portion of the engine power is mounted on the input shaft. Part, and
The input shaft, the PTO output shaft, and the traveling output shaft are relatively arranged so that the input section and the traveling transmission case are disposed on the left and right sides of the PTO transmission case.
In addition to the above configuration, it is advantageous that a torque limiter acting on the traveling output shaft is provided on the upper transmission side of the gear transmission, and a transmission intermediate shaft having a shift gear is added to the traveling transmission system. It is even more advantageous if the traveling output shaft is configured to be capable of multi-speed shifting.

[0005]

With reference to FIG. 3, in the configuration of claim 1, a transmission input shaft 8 for forming a belt mechanism extending to the engine is disposed on the left side of the gear transmission 2 and traveling on the right side of the gear transmission 2. The chain case 11 is arranged, and the PTO chain case 13 is arranged at the left and right central portions of the body. Therefore, in this transmission layout, a single drive wheel can be disposed at the center in the left and right direction by extending the axle to the left from the traveling chain case 11, and P
The TO transmission case 13 can be arranged at the center on the left and right just by attaching it to the transmission case.
A one-wheeled walk-behind work machine can be configured without using the O auxiliary chain case (reference numeral 17 in FIG. 4 of JP-A-6-153604). That is, the structure of the PTO auxiliary transmission case portion is in a state as if it was installed in the transmission case.

[0006] In order to form a two-wheel type, the traveling chain case is shortened, an auxiliary traveling chain case is disposed at a wheel disposing portion in the case of a one-wheel type, and axles are protruded on both right and left sides. It is also possible to standardize the gear transmission with less modification. In other words, in the walking type working machine, although there is a difference between the one-wheel type and the two-wheel type, the power input portion in the working device such as the tilling rotary exists in the left and right central portions of the body,
With this recognition, the configuration described above was adopted.

A PTO is provided between the input shaft and the traveling output shaft.
The gears that make up the transmission system and the gears that make up the traveling transmission system
Since the fitted transmission shaft is interposed, for example,
Compared to the case where a transmission shaft equipped only with gears is
The number of shafts for the total number of gears in the dynamic system and PTO transmission system is small.
And the gear transmission can be made more compact.
It will work. In other words, the figure of the public utility Heisei 3-54106
In the plane shown in FIG.
C) with a first intermediate shaft (symbol 16)
7 steps, 2 steps forward and 1 step reverse, 2 steps PTO forward and reverse
The speed is controlled by five axes, whereas the speed is controlled by five axes.
Is a total of eight gears, two forward and two reverse gears and two PTO forward and reverse gears.
Axis.

According to the second aspect of the present invention, since the traveling system torque limiter is provided, even if, for example, a stone is locked between the driving wheels and the traveling transmission case and locked, the torque limiter is used. The transmission is cut off, and the possibility of damage such as cutting of a pin for fixing the wheel to the axle is avoided, and the traveling transmission system is protected. Further, since the torque limiter is provided on the upper transmission side where a relatively low torque acts, a smaller capacity may be used as compared with the case where the torque limiter is provided on the lower transmission side where a high torque acts.

According to the third aspect of the present invention, the speed change intermediate shaft is added to the traveling power transmission system to perform multi-speed transmission. However, since the PTO transmission system and the traveling power transmission system are divided into right and left, the PTO transmission system is divided into left and right.
The additional setting of the axis is possible without affecting the transmission system, and it can be realized by a relatively small-scale modification of only the traveling transmission system.

[0010]

Effect of the Invention] Accordingly, the walk-behind working machine according to claim 1, simplification and reduction of the number of parts structure by omitting the PTO auxiliary chain case are possible, Mi by effective use of the shaft
A rational and more sophisticated transmission that can reduce the size of the case is realized. The walking type working machine according to the second aspect has an advantage that the traveling power transmission system can be sufficiently protected while being a small-sized torque limiter which is advantageous in cost. Are added in each case.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a walking-type cultivator as an example of a walking-type work machine, in which 1 is an engine, 2 is a gear transmission,
3 is a running wheel, 4 is a tilling rotary, 5 is a steering wheel,
Reference numeral 6 denotes an engine mounting frame, and 9 denotes a belt transmission mechanism having an engine output shaft 7 and a transmission input shaft 8. A traveling chain case (corresponding to a traveling transmission case) 11 that links the axle 10 and the gear transmission 2 extends downward and forward, and a rotary chain case (PTO transmission case) that links the rotary shaft 12 and the gear transmission 2. 13)
Extends downward and rearward. Next, various embodiments of the gear transmission 2 will be described.

[First Embodiment] As shown in FIGS. 2 and 3, the gear transmission 2 includes an input shaft 8, a transmission shaft 14, a traveling output shaft 15, a relay shaft 16, and a PTO.
An output shaft 17 is provided in the transmission case 2a, and a traveling fourth gear 18 in a loosely fitted state and a PTO shift gear 19 in a spline outer fitted state are fitted on the input shaft 8 integrally formed with the first traveling gear 8a. A traveling forward / reverse shift gear 20 is fitted on the fourth traveling gear 18 outside the spline. Traveling 3rd
On the transmission shaft 14 integrally formed with the gear 14a, a traveling second gear 21 in an externally fitted spline state, a traveling transmission shift gear 22 in a loosely fitted state via a bush, and a PTO first gear 23 are fitted. A PTO second gear 24 and a PTO forward / reverse shift gear 25 are spline-fitted to the cylindrical shaft portion of the PTO first gear 23.

The traveling output shaft 15 has a torque limiter T
, A low-speed running fifth gear 27, and a high-speed running sixth gear 28 are externally fitted with the spline, and the wide PTO second gear 29 is loosely fitted. The relay shaft 16 has a PTO second gear 29
The bifurcated PTO third gear 30 that meshes with the spline is fitted outside the spline. On the PTO output shaft 17, a PTO drive sprocket 31 and a PTO clutch shifter 33 are fitted outside the spline, and a PTO fourth gear 32 meshing with the PTO third gear 30 is loosely fitted to be relatively rotatable.
The PTO clutch 34 is configured by biasing the PTO clutch shifter 33 toward the side that meshes with the fourth PTO gear 32.

That is, the gear transmission 2 includes a PTO transmission system A having an input shaft 8 and a PTO output shaft 17 on the left side.
The transmission transmission system B having the traveling output shaft 15 is arranged on the right side while being distributed in the transmission case 2a. The PTO output shaft 17 is provided with the rotary chain case 13 for the tilling rotary 4 by the traveling output system. A traveling chain case 11 for driving wheels is mounted on the shaft 15, and an input pulley 8 P, which is an input portion for engine power, is mounted on the input shaft 8. The rotary chain case 13 is disposed at the center of the machine body in the left-right direction, and the input pulley 8P is on the left (to the right in FIG. 2) of the rotary chain case 13 and is to the right (to the left in FIG. 2). Are arranged respectively.

[0015] Also, as shown in FIG. 4, a traveling output shaft 15 and the center distance D ₁ of the input shaft 8 and the driving output shaft 15 and the center distance D ₂ between the speed-change shaft 14 equivalent (D ₁ = the D _2), and a transmission shaft 14 and the center distance D ₃ between the intermediate shaft 16, equivalent to the center distance D ₂ between the speed-change shaft 14 and the travel output shaft 15 (D
₃ = D ₂ ).

Next, each shift state will be described. In the forward running low speed state, the forward / reverse shift gear 20 is moved to the neutral position (the position shown in FIG. 3).
By operating the traveling shift gear 22 to the low speed position (the position to the right from the position in FIG. 3), the input shaft 8 → the traveling first gear 8a → the traveling second gear 21 → the traveling third gear 14
a → the fourth traveling gear 18 → the traveling forward / reverse shift gear 20 → the traveling transmission shift gear 22 → the traveling fifth gear 27 → the torque limiter T → the traveling drive sprocket 26. In the forward running high speed state, the forward / reverse shift gear 20 is moved to the neutral position (the position shown in FIG. 3).
At the same time, the traveling speed shift gear 22 is operated to the high-speed position (the position to the left from the position in FIG. 3). The transmission path is the same as in the case except that the fifth running gear 27 is replaced with the sixth running gear 28.

The traveling reverse rotation low speed state The traveling forward / reverse shift gear 20 is operated to the low speed position (the position to the right from the position in FIG. 3), and the traveling speed change gear 22 is operated to the neutral position (the position in FIG. 3). In this state, the traveling forward / reverse shift gear 20 directly meshes with the traveling fifth gear 27, and the input shaft 8 → the traveling first gear 8a → the traveling second gear 2
1 → the third traveling gear 14a → the fourth traveling gear 18 → the traveling forward / reverse shift gear 20 → the fifth traveling gear 27 → the torque limiter T → the traveling drive sprocket 26. Traveling Reverse High Speed State The traveling forward / reverse shift gear 20 is operated to the high speed position (the position to the left from the position in FIG. 3) and the traveling speed change gear 22 is operated to the neutral position (the position in FIG. 3). In this state, the traveling forward / reverse shift gear 20 directly meshes with the traveling sixth gear 28, and the transmission path is the same as that in the case except that the traveling fifth gear 27 is replaced with the traveling sixth gear 28.

PTO forward rotation low speed state The PTO shift gear 19 is in the low speed position (left position from the position in FIG. 3), and the PTO forward / reverse shift gear 25 is in the forward position (left position from the position in FIG. 3). , The input shaft 8 → PTO shift gear 19 → PTO first gear 23 → PTO forward / reverse shift gear 25 → PTO second gear 29 → PTO third gear 30 → PTO clutch 34 → P
It is transmitted along the path of the TO drive sprocket 31. PTO normal rotation high speed state The PTO shift gear 19 is operated to the high speed position (the position to the right from the position in FIG. 3), and the PTO normal / reverse shift gear 25 is operated to the normal rotation position (the position to the left from the position in FIG. 3). . The transmission path is the same as in the case except that the PTO first gear 23 is replaced with the PTO second gear 24.

PTO reverse rotation low speed state The PTO shift gear 19 is operated to the low speed position (left position from the position in FIG. 3), and the PTO forward / reverse shift gear 25 is operated to the reverse position (right position from the position in FIG. 3). I do. In this case, the PTO forward / reverse shift gear 25 is directly
The input gear 8 is engaged with the gear 30, and the input shaft 8 → the PTO shift gear 19 → the first PTO gear 23 → the PTO forward / reverse shift gear 25 → the third PTO gear 30 → the PTO clutch 34.
→ It is transmitted along the path of the PTO drive sprocket 31. PTO reverse rotation high speed state The PTO shift gear 19 is operated to the high speed position (position to the right from the position in FIG. 3), and the PTO forward / reverse shift gear 25 is operated to the reverse position (right position from the position in FIG. 3). The transmission path is the same as in the case except that the PTO first gear 23 is replaced with the PTO second gear 24.

[Second Embodiment] As shown in FIGS. 5 and 6, a transmission intermediate shaft 35 having a second transmission shift gear 36 is added to the traveling transmission system B based on the gear transmission 2 of the first embodiment. Alternatively, the traveling output shaft 15 may be configured to be capable of four-stage (multi-stage) shifting. That is, the input shaft 8, the transmission shaft 14, and the traveling output shaft 15
The regular forward / reverse shift gear 20 that meshes with the intermediate gear 35a of the transmission intermediate shaft 35 includes a traveling transmission shift gear 22, a traveling low speed gear 27, and a traveling high speed gear 28. And can be occluded. Contrary to the first embodiment, a PTO forward / reverse shift gear 25 is fitted on the input shaft 8 and a PTO speed change gear 19 is fitted on the speed change shaft 14. The forward / reverse shift gear 20 is loosely fitted to the input shaft 8.

Accordingly, each shift state in FIG. 5 is as follows. (1) First forward running speed The forward / reverse shift gear 20 is moved to the neutral position (the position shown in FIG. 5).
By operating the traveling second shift gear 36 to the low speed position (the position to the left from the position in FIG. 5) and the traveling speed shift gear 22 to the low speed position (the position to the right from the position in FIG. 5), the forward rotation is achieved. The first speed state appears. (2) Second forward running speed The forward / reverse shift gear 20 is shifted to the neutral position (the position shown in FIG. 5).
By operating the traveling second shift gear 36 to the low-speed position (the position to the left from the position in FIG. 5) and the traveling speed shift gear 22 to the high-speed position (the position to the left from the position in FIG. 5), the forward rotation is achieved. The second speed state appears. (3) Third forward running speed The forward / reverse shift gear 20 is moved to the neutral position (the position shown in FIG. 5).
By operating the traveling second shift gear 36 to the high-speed position (the position to the left from the position in FIG. 5) and the traveling speed shift gear 22 to the low-speed position (the position to the right from the position in FIG. 5), the forward rotation is achieved. The third speed condition appears. (4) Fourth forward running speed The forward / reverse shift gear 20 is moved to the neutral position (the position shown in FIG. 5).
By operating the traveling second shift gear 36 to the high-speed position (the position to the right from the position in FIG. 5) and the traveling speed shift gear 22 to the high-speed position (the position to the left from the position in FIG. 5), the forward rotation is achieved. Fourth gear state appears.

(5) First Traveling Reverse Speed The forward / reverse shift gear 20 is moved to the low speed position (the position to the right from the position in FIG. 5), and the second speed shift gear 36 is moved to the low speed position (the left position from the position in FIG. 5). ), And by operating the traveling speed change shift gear 22 to the neutral position (the position in FIG. 5), the reverse first speed state appears. (6) Second traveling reverse speed The traveling forward / reverse shift gear 20 is in the high-speed position (the position to the left from the position in FIG. 5), and the second traveling speed shift gear 36 is in the low-speed position (the left position from the position in FIG. 5). In addition, by operating the traveling speed shift gear 22 to the neutral position (the position in FIG. 5), the second reverse speed state appears. (7) Third Travel Reverse Speed The forward / reverse shift gear 20 is moved to the low speed position (the position to the right from the position in FIG. 5), and the second speed shift gear 36 is moved to the high speed position (the right position from the position in FIG. 5). By operating the traveling shift gear 22 to the neutral position (the position shown in FIG. 5), the third reverse rotation state is realized. (8) Traveling reverse 4th speed The traveling forward / reverse shift gear 20 is in the high-speed position (the position to the left from the position in FIG. 5), and the traveling second speed-change shift gear 36 is in the high-speed position (the position to the right from the position in FIG. 5). By operating the traveling shift gear 22 to the neutral position (the position in FIG. 5), the reverse fourth speed state appears.

(9) PTO 1st forward rotation The PTO forward / reverse shift gear 25 is in the neutral position (the position shown in FIG. 5).
And the PTO shift gear 19 is moved to the low speed position (FIG. 5).
From the position to the right). (10) PTO forward 2nd speed PTO forward / reverse shift gear 25 is in neutral position (position in FIG. 5).
And the PTO shift gear 19 is moved to the high-speed position (FIG. 5).
From the position to the left). (11) PTO reverse rotation 1st speed The PTO forward / reverse shift gear 25 is operated to the low speed position (the position to the right from the position in FIG. 5), and the PTO shift gear 19 is operated to the neutral position (the position in FIG. 5). (12) PTO reverse second speed The PTO forward / reverse shift gear 25 is operated to the high speed position (the position to the left from the position in FIG. 5), and the PTO shift gear 19 is operated to the neutral position (the position in FIG. 5).

[Third Embodiment] As shown in FIG. 7, the transmission intermediate shaft 35 in the second embodiment
Instead of the traveling second shift gear 36, a forward and reverse two-stage gear transmission 2 equipped with a torque limiter T may be used. The torque limiter T includes a base cylinder 37 that is splined to the transmission intermediate shaft 35, a fixed cam body 38 that is splined to the base cylinder 37, and a movable cam body 39 that is freely rotatably fitted to the base cylinder 37. , A ball 40, a disc spring 41, a double nut 42, and the like. A gear portion 39 a formed on the movable cam body 39 is engaged with the first traveling gear 8 a, and further, the spline is externally fitted to the transmission intermediate shaft 35. The gear 35a meshes with the traveling forward / reverse shift gear 20.

Further, in the first embodiment, the two-stage reduction portion g formed between the input shaft 8 and the transmission shaft 14 is provided between the transmission shaft 14 and the traveling output shaft 15 similarly to the second embodiment. It is configured. Except for these changed parts, it basically has the same functions as the gear transmission 2 of the first embodiment. Thus, by providing the torque limiter T on the transmission intermediate shaft 35 located on the transmission upper side, the torque limiter T is provided on the transmission lower side as in the first embodiment.
There is an advantage that a small one for low torque can be used. by the way,
The structure of the torque limiter T of the first embodiment shown in FIG.
The ball type is basically the same as that of the third embodiment shown in FIG.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a side view of a one-wheel walking tiller.

FIG. 2 is a developed plan view showing a layout state of the aircraft.

FIG. 3 is a developed view showing the gear transmission structure of the first embodiment.

FIG. 4 is a side view showing a shaft arrangement of the gear transmission shown in FIG. 3;

FIG. 5 is a developed view showing a gear transmission structure according to a second embodiment.

FIG. 6 is a side view showing the shaft arrangement of the gear transmission shown in FIG. 5;

FIG. 7 is a developed view showing a gear transmission structure of a third embodiment.

[Explanation of symbols]

2 Gear transmission 2a Casing 8 Input shaft 8P Input section 11 Travel transmission case 13 PTO transmission case 15 Travel output shaft 14 Transmission shaft 17 PTO output shaft 35 Transmission intermediate shaft 36 Shift gear A PTO transmission system B Travel transmission system

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A01B 33/08 A01B 71/02 B60K 17/28

Claims (3)

(57) [Claims] 1. A PTO transmission system (A) having an input shaft (8) and a PTO output shaft (17) and a traveling transmission system (B) having a traveling output shaft (15) are divided into left and right. constitute a gear transmission (2) in the arrangement state is housed in the casing (2a), before in the gear transmission (2)
Between the input shaft (8) and the traveling output shaft (15).
Gears constituting the PTO transmission system (A) and the traveling transmission system
(B) via a speed change shaft (14) fitted with the gears.
The PTO output shaft (17) is equipped with a PTO transmission case (13) for driving a working device, the traveling output shaft (15) is equipped with a traveling transmission case (11) for driving wheels, and the input shaft (8). ), An input unit (8P) for engine power is attached to each of the PTO transmission cases (13), and the PTO transmission case (13) is disposed at a substantially central portion in the lateral direction of the fuselage. The walking in which the input shaft (8), the PTO output shaft (17), and the running output shaft (15) are relatively arranged so that the portion (8P) and the running transmission case (11) are arranged. Transmission of type work machine. 2. The walking type working machine according to claim 1, wherein a torque limiter (T) acting on the traveling output shaft (15) is provided on a transmission upper side portion of the gear transmission (2). Gearing. 3. The traveling output shaft according to claim 2, wherein an intermediate transmission shaft (35) including a shift gear (36) is added to the traveling transmission system (B) so that the traveling output shaft can be shifted in multiple stages. Transmission device for walking type working machine.