JPH11346512A - Gear transmitting device for rice transplanter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear transmitting device for a rice transplanter capable of reducing the capacity of a one-way clutch for transmitting only a normal rotation power to a seedling planting device and effectively acting even on the miniaturization of an intrarow speed changing mechanism. SOLUTION: This gear transmitting device for a rice transplanter is composed by freely rotatably supporting a back shaft 35 equipped with a back gear G7 over both walls of a transmission case 9, externally fitting and attaching a cylinder shaft 51 integrally and rotatably equipped with a gear group on the driving side of an intrarow speed changing mechanism 29 and attaching a gear G18 receiving the power passing through an advancing and backing speed changing mechanism 24 through a one-way clutch 52 to the cylinder shaft 51 so as to transmit only the power in the advancing rotative direction passing through the advancing and backing speed changing mechanism 24 through the one-way clutch 52 to the cylinder shaft 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gear transmission used for a riding type rice transplanter.

[0002]

2. Description of the Related Art An example of a gear transmission of a riding type rice transplanter is disclosed in Japanese Patent Application Laid-Open No. 10-110804. This gear transmission is the first in the transmission case.
The output of the engine (not shown) is transmitted to the transmission shaft via a main transmission mechanism including a belt-type continuously variable transmission, and the power is transmitted to the second transmission shaft, and then transmitted via a multi-plate main clutch. The transmission output is transmitted to the forward / reverse transmission mechanism, and the output of the transmission is transmitted to the transmission shaft, which is the final transmission shaft, via the auxiliary transmission mechanism that performs three-step shifting, and the final transmission power is transmitted to the left and right front wheel shafts via the differential mechanism. In addition, the transmission is transmitted to a rear wheel (not shown) via a transmission shaft, and the vehicle can be driven by four-wheel drive.

Further, the output from the forward / reverse transmission mechanism is
The gears are transmitted to the input side transmission shaft of the first inter-gear transmission mechanism disposed coaxially with the back shaft, and the output shifted in three stages is taken out via the second inter-gear transmission mechanism, the torque limiter, and the planting clutch. The shaft is transmitted to a seedling planting device connected to the rear of the machine. In order to prevent the reverse rotation power from being transmitted to the seedling planting device, only the forward rotation of the transmission shaft is input between the input side gear of the second inter-gear transmission mechanism and the transmission shaft supporting the same. There was a one-way clutch that transmitted to the side gear.

[0004]

In the above-mentioned conventional structure, the load torque acting on the one-way clutch is large because the shaft provided with the one-way clutch is a transmission shaft having a relatively low rotational speed of the transmission lower hand. Therefore, it was necessary to use a one-way clutch having a large capacity. Also, the input-side transmission shaft and the back shaft of the first inter-gear transmission mechanism are coaxially inserted and connected to form a single shaft, and both ends thereof are supported by the case wall. In order to ensure the bending strength, it is necessary to take measures such as enlarging the shaft diameter, and this has led to an increase in the size of the first inter-gear transmission mechanism.

Further, in a gear type transmission equipped with a shift member, the shift fork shaft is located near the case wall. Must be detoured between various transmission shafts, and if the distance between the shafts is reduced due to the small size of the transmission structure, the strength of the shift fork itself, which passes through the narrow space between the shafts, will not be sufficient. Met. Of course, such problems can be reduced by increasing the distance between the various transmission shafts. However, the transmission case becomes large, which is inconvenient for a rice transplanter that is particularly required to be lightweight.

The present invention has been made in view of the above point, and enables the one-way clutch to have a small capacity, and is effective for downsizing the inter-stock transmission mechanism. It is an object of the present invention to provide a gear transmission that is also effective for downsizing.

[0007]

Means for Solving the Problems [Structure, operation and effect of the invention according to claim 1]

(Structure) According to the first aspect of the present invention, a back shaft provided with a back gear is rotatably supported across both walls of a transmission case, and a drive-side gear group of the inter-stock speed change mechanism is integrally rotatable. A cylindrical shaft is mounted on the back shaft in a freely rotatable manner, and a gear receiving power via a forward / reverse transmission mechanism is mounted on the cylindrical shaft via a one-way clutch, and a forward rotation direction via a forward / reverse transmission mechanism is provided. Is transmitted to the cylinder shaft via the one-way clutch.

(Operation) According to the above configuration, since the back shaft is a transmission shaft having a relatively high rotational speed, the load torque acting on the one-way clutch mounted thereon is small. In addition, since one back shaft is supported across both walls of the transmission case, shaft strength can be sufficiently secured as compared with a case where the back shaft is butt-fitted into a single shaft.

(Effects) Therefore, according to the first aspect of the present invention, the one-way clutch can have a small capacity, and the shaft diameter can be reduced as much as the shaft strength can be secured. This is effective for reducing the size and weight.

[Structure, operation and effect of the invention according to claim 2]

(Structure) According to a second aspect of the present invention, there is provided a transmission shaft and a shift fork shaft which have a through hole formed in an intermediate portion between a fork portion and a shaft support base in a shift fork of a transmission mechanism, and which support a shift member. It is characterized in that another adjacent transmission shaft is inserted into the through hole.

(Operation) According to the above configuration, the intermediate portion between the fork portion and the shaft support base of the shift fork can be widened, and the strength of the shift fork can be reduced as compared with the case where the shift fork is disposed between the shafts. By forming a high shift fork, a reliable gear shift can be performed.

(Effects) Therefore, according to the second aspect of the present invention, it is possible to dispose the shift fork for operating the shift member provided on the transmission shaft inside the transmission case without increasing the distance between the transmission shafts. However, a high-strength shift fork can be formed, and the transmission case can be reduced in size and weight, and can be effectively used for a gear transmission of a rice transplanter that requires a reduction in weight.

[0015]

FIG. 1 shows an overall side view of a riding type rice transplanter with a fertilizer application device. In this rice transplanter, a seedling planting device 5 is connected to a rear portion of a riding traveling vehicle body 3 having a driven front wheel 1 and a rear wheel 2 via a hydraulically driven link mechanism 4 so as to be movable up and down. A fertilizer application device 6 buried beside the planting seedling is provided at the rear of the driver's seat 7. An engine 8 is mounted on the front of the traveling vehicle body 3, and the engine output is transmitted to a transmission case 9 supporting the front wheels 1 by a belt-type continuously variable transmission 10.
, The gears are further shifted by the transmission case 9 to drive the front wheels 1, and the transmission output taken out of the transmission case 9 transmits the transmission shaft 12 to the rear transmission case 11 that supports the rear wheels 2. The work output taken out from the transmission case 9 and taken out of the transmission case 9 is transmitted to the seedling planting apparatus 5 via the transmission shaft 13.

FIGS. 2 to 4 show the internal structure of the transmission case 9. Basically, the transmission output of the belt-type continuously variable transmission 10 is first transmitted to a first transmission shaft (input shaft).
21 through the gears G1 and G2.
After being transmitted to the hydraulically driven multi-plate main clutch 2
3. The transmission is shifted through the forward / reverse transmission mechanism 24 and the auxiliary transmission mechanism 25, and the transmission output is transmitted to the front wheel differential mechanism 26 to drive the left and right front axles 27 and to branch at the front wheel differential mechanism 26. The changed power is taken out from the output shaft 28 and is transmitted to the rear transmission case 11. Further, after the output of the forward / reverse transmission mechanism 24 is shifted by the first inter-stock transmission mechanism 29 and the second inter-stock transmission mechanism 30, the torque limiter 31 and the planting clutch 3
2, the power is transmitted to the working power take-out shaft 33.

More specifically, gears G3 and G4 interlocked with the driven side of the main clutch 23 are loosely fitted to the second transmission shaft 22, and one of the gears G3 is loosely fitted to the third transmission shaft 34. The gear G5 is always engaged with the gear G5, and the other gear G4 is always engaged with the gear G6 fixed to the back shaft 35, and the gear G7 fixed to the back shaft 35 and the second transmission shaft 22.
Gear G8 which is loosely fitted to the gear is always engaged. And
Between the G5 and G8, a shift sleeve 3 as a shift member for performing a forward-reverse shift in a constant mesh system.
6, the shift sleeve 36 is shifted to the left in the figure to integrate G5 with the third transmission shaft 34, thereby providing a forward drive state in which the third transmission shaft 34 is driven to rotate forward. Conversely, by shifting the shift sleeve 36 rightward in the drawing to integrate G8 with the third transmission shaft 34, a reverse state in which the third transmission shaft 34 is driven to rotate in the reverse direction is brought about. ing.

As shown in FIG. 4, the shift sleeve 3
A shift fork 37 for shifting the gear 6 is connected to a shift fork shaft 38 slidably mounted on the transmission case 9 in a laterally slidable manner, and a fork portion 37a engaging with the shift sleeve 36 and a shaft support base for the shift fork shaft 38. A through hole 39 is formed at an intermediate portion with the hole 37b, and the second transmission shaft 22 is inserted into the through hole 39. As described above, the rigidity of the shift fork is increased by the wide configuration of the shift fork itself. The shift shaft 38 is mechanically linked via a link mechanism 42 to a shift lever 41 provided on the left side of the steering handle 40, and the shift shaft 38 is connected to an end of the shift shaft 38. A sequence valve 43 for controlling a main clutch which is a spool is provided. When the shift fork 37 is at the forward position F or the reverse position R, the supply of the pressure oil to the main clutch 23 is cut off and the main clutch 23
When the shift fork 37 is disengaged from the forward position F or the reverse position R by the interior spring 44, pressure oil is supplied through the in-shaft oil passage 45, and the piston 46 is displaced to the right in the figure, and the main clutch The clutch 23 is configured to be "clutch disengaged", and the forward / reverse switching speed can be changed by non-clutch operation only by the shift lever 41. Although the structure is omitted, the main clutch 23 can also be mechanically "disengaged" by depressing the main clutch pedal 47 for a sub-shift operation described later.

The auxiliary transmission mechanism 25 includes a small gear G9 and a middle gear G1 which are integrated or fixedly connected to the third transmission shaft 34.
0, a large gear G11, a gear G12 loosely fitted to the fourth transmission shaft 48 so as to always mesh with the small gear G9, and a two-stage shift gear Gs1 spline-mounted to the fourth transmission shaft 48.
The shift gear Gs1 is shifted rightward in FIG. 2 and directly engaged with and connected to the gear G9 from the side, so that a minimum speed suitable for crossing a ridge or loading / unloading a vehicle can be obtained. Large gear G13 of the third transmission shaft 34 to the middle gear G
By interlocking with 10, the medium speed suitable for planting and running can be obtained, and by engaging the small gear G14 of the shift gear Gs1 with the large gear G11 of the third transmission shaft 34, the maximum speed suitable for moving and running can be obtained. You can get it.

The rotation of the fourth transmission shaft 48 is transmitted to the input gear G16 of the front wheel differential mechanism 26 via a pinion gear G15 provided at the end thereof, and the input gear G
The output power is transmitted to an output shaft 28 for driving the rear wheels via a bevel gear G17 integrated with the gear 16. The front wheel differential mechanism 26 is provided with a differential lock mechanism 49 so that the left and right front wheels 1 can be driven at a constant speed when, for example, crossing a ridge.

FIG. 3 shows a transmission structure to the seedling planting apparatus 5. The back shaft 35 is supported on the left and right walls of the transmission case 9 in a double-supported manner.
A gear G18 externally fitted to the cylindrical shaft 51 loosely fitted to the back shaft 35 via a one-way clutch 52 is always meshed with the large gear G11 for auxiliary transmission fixed to the third transmission shaft 34. Here, the characteristics of the one-way clutch 52 are set so that only the forward rotation power of the third transmission shaft 34 is transmitted to the cylindrical shaft 51.

The first inter-gear transmission mechanism 29 is mounted on the cylindrical shaft 51.
Gears G19, G20, and G21 are integrally formed, and the first gear 53 of the planting system is provided with these gears G19, G20, and G21.
Two-stage shift gear Gs2 that selectively meshes with 19, G20, G21
Are fitted with splines. The first shaft 53 has a pair of gears G22 and G constituting the second inter-gear transmission mechanism 30.
23 is spline-mounted, and the second shaft 54 of the planting system is spline-mounted with a two-stage shift gear Gs3 which is selectively engaged with these gears G22 and G23. By shifting the speed of the inter-stock transmission mechanism 30, the second shaft 54 of the planting system can be shifted to six speeds. The transmission power of the second shaft 54 is transmitted to the torque limiter 31 via the bevel gears G24 and G25, and then output to the rear of the machine through the planting clutch 32. As described above, the shaft transmission to the seedling planting apparatus 5 is performed. It is supposed to be.

[Brief description of the drawings]

FIG. 1 is an overall side view of a riding rice transplanter.

FIG. 2 is a cross-sectional view showing a transmission structure of a traveling system in a transmission case.

FIG. 3 is a cross-sectional view showing a transmission structure of a planting system in a transmission case.

FIG. 4 is a cross-sectional view around a main clutch.

FIG. 5 is a front view showing a shaft arrangement and a forward / reverse speed shift fork in a transmission case.

[Explanation of symbols]

 Reference Signs List 9 transmission case 22 transmission shaft 24 forward / reverse transmission mechanism 35 back shaft 36 shift member (sleeve) 37 shift fork 37a fork portion 37b shaft support base 38 shift fork shaft 39 through hole G7 back gear

Claims (2)

[Claims] 1. A back shaft provided with a back gear is rotatably supported across both walls of a transmission case, and a cylinder shaft provided with a drive side gear group of an inter-stock transmission mechanism so as to be integrally rotatable is freely rotated on the back shaft. A gear that receives power via a forward / reverse transmission mechanism is mounted on this cylinder shaft via a one-way clutch, and only the power in the forward rotation direction via the forward / reverse transmission mechanism is applied to the one-way clutch. A gear transmission for a rice transplanter, wherein the gear transmission is configured to be transmitted to a cylinder shaft via a shaft. 2. A transmission fork of a transmission mechanism, wherein a through hole is formed at an intermediate portion between a fork portion and a shaft support base, and another transmission shaft adjacent to the transmission shaft supporting the shift member and the shift fork shaft is connected to the transmission shaft. A gear transmission for a rice transplanter, wherein the gear transmission is configured to be inserted through a hole.