JP2000198362A - Front-wheel drive device for tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate assembling/disassembling of a hydraulic clutch and improve the maintenance and inspection workability by forming an opening part in the bottom side of a gear case mounted on the lower belly part of a transmission case constituting a tractor body. SOLUTION: A 2-axle and 4-wheel tractor is so formed that a front wheel drive device 9 is mounted on the lower belly part of a tractor body 8 sequentially providing a transmission case to an engine via clutch housing and the power of the engine is transmitted to the front wheel thereby via a front-wheel differential gear, etc. A clutch shaft 31 is journalled to a gear case 30 formed with an opening part 30 at a lower face side of the front wheel drive device 9 and having support arms 30B, 30C in its front and rear via bearings 31A, 31B. A pack assembly is constituted of a constant-velocity hydraulic clutch 32 and an accelerating hydraulic clutch 33 fittedly supported by the clutch shaft 31 and mounted on the tractor body 8 with an opening part 8A formed in the lower belly part of the tractor body 8 closed thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front wheel drive device for a tractor, and more specifically, to drive a front wheel at a higher speed with respect to a rear wheel when making small turns on a headland or the like in a field or the like. The present invention relates to a front wheel drive device for a tractor that drives the front wheels at a constant speed (including a substantially constant speed) with respect to the rear wheels while traveling on a road or the like.

[0002]

2. Description of the Related Art A constant-speed hydraulic clutch and a speed-increasing hydraulic clutch are fitted and supported on a transmission shaft of a front wheel in a gear case, and the gear case is mounted on a lower abdomen of a transmission case constituting a tractor body. The front wheel drive device of the tractor to be mounted is known in Japanese Patent Application Laid-Open No. 54-120138 (conventional example 1) and Japanese Patent Publication No. 7-100144 (conventional example 2).

[0003]

One of the conventional examples is that a constant-speed hydraulic clutch and a speed-increasing hydraulic clutch are provided side by side on a clutch shaft and are incorporated in a transmission case constituting a tractor vehicle body, and the clutch shaft is mounted on the clutch shaft. Since the gear and the gear on the power take-off shaft are engaged with each other, it is impossible to assemble and disassemble the two clutches even if the gear case is attached or detached, since the cassette is not formed. The second conventional example merely discloses a configuration in which the two clutches are provided side by side, but does not refer to incorporating both clutches into a gear case in a cassette configuration. .

Accordingly, the present invention provides a constant-speed hydraulic clutch and a speed-increasing hydraulic clutch arranged side by side on a transmission shaft of a front wheel and assembled in a gear case in a cassette configuration, and an opening formed on the lower surface side of the gear case is closed by a cover body. Accordingly, it is an object of the present invention to facilitate the maintenance and inspection of the hydraulic clutch while easily assembling and disassembling the hydraulic clutch.

[0005]

According to the present invention, a constant-speed hydraulic clutch and a speed-increasing hydraulic clutch are inserted and supported in a gear case on a transmission shaft of a front wheel, and the gear case is mounted on a tractor body. In the front wheel drive device of the tractor mounted on the lower abdomen of the transmission case, the following technical measures are taken in order to achieve the above object. That is, the present invention is characterized in that an opening is formed on the lower surface side of the gear case, and a cover body for closing the opening is detachably attached to the gear case.

[0006] By adopting such a configuration,
The constant-speed hydraulic clutch and the speed-increasing hydraulic clutch are assembled in a gear case in a cassette configuration. This cassette assembly is mounted on the lower abdomen of the transmission case to facilitate assembly and disassembly of the hydraulic clutch. By attaching and detaching the hydraulic clutch from the gear case, maintenance and inspection of the hydraulic clutch became easy. According to the present invention, in the configuration of claim 1, an oil passage for the hydraulic clutch is formed in the transmission shaft in the axial direction, and a cap for supporting one axial end of the transmission shaft in an oil-tight manner. The body is mounted so as to be retrofittable to the gear case (claim 2).

By adopting such a configuration,
When the cap member is retrofitted to the cap body, the seal member attached to one end in the axial direction of the transmission shaft is less likely to be turned up, and the oil tightness is reliably maintained. Further, in the present invention, in the structure of claim 1 or 2, an electromagnetic valve for turning on / off the hydraulic clutch is mounted on a side surface of the gear case (claim 3). By adopting such a configuration, a hydraulic pipe and a joint are not required between the electromagnetic valve and the gear case, so that the cause of oil leakage is reduced, and the cost can be reduced by reducing the number of parts.

[0008] Further, in claim 2 or 3 described above,
It is desirable that the electromagnetic valve be provided in connection with the cap body (claim 4).

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 7, a two-axis four-wheel tractor 1 to which the present invention is directed is illustrated, and the tractor 1 includes left and right front wheels 2 having a function as a steering wheel.
And a transmission case 7 connected to an engine 5 covered by a hood 4 via a clutch housing 6 to form a tractor body 8. The front wheel drive device 9 according to the present invention includes a tractor body 8.
And can drive the left and right front wheels 2 via a front wheel propulsion shaft device 10 and a front wheel differential device 11,
The front wheel differential device 11 is supported on a front axle frame 12 by a center pin method. In FIG. 7, reference numeral 13 denotes a steering wheel, and reference numeral 14 denotes a driver's seat.

Referring to FIG. 1, the clutch housing 6
A main clutch 15 is mounted on the inside of the vehicle.
It is possible to intermittently. The traveling system propulsion shaft 17 has a cylindrical shaft configuration, and a PTO propulsion shaft 18 is inserted into the cylinder shaft. The tip of the propulsion shaft 18 is directly connected to an engine output shaft 19. It is linked to an external PTO transmission. In the room 21 of the mission case 7,
A main transmission 2 capable of constantly engaging with a four-speed transmission on a transmission auxiliary shaft 22 and a transmission output shaft 23 disposed above and below the propulsion shaft 17.
4. A sub-transmission 25, a super-transmission 26, and a reverse device capable of shifting between high and low gears are incorporated, and a front wheel drive device according to the present invention is provided on the front side (front side) of the transmission output shaft 23. 9 is provided, and the speed change output shaft 23 is connected to a differential drive shaft 29 via a coupling 28 at a rear portion thereof, and a rear wheel differential is provided via the differential drive shaft 29. It is operatively connected to a device (not shown).

Referring to FIGS. 2 and 3, a first embodiment of a front wheel drive device 9 according to the present invention is illustrated. The front wheel drive device 9 includes a gear case 30 having an opening 30A formed on the lower surface side and projecting support arms 30B and 30C apart from each other, and a bearing 31A inserted and supported by the gear case 30 and having front and rear portions. , 31B rotatably supported by the transmission shaft (clutch shaft) 31
And a pack assembly composed of a constant-speed hydraulic clutch 32 and a speed-increasing hydraulic clutch 33, which are fitted and supported on the clutch shaft 31, and the opening 8A formed in the lower abdomen of the tractor body 8 is closed. It can be mounted on.

The front and rear support arms 30B of the gear case 30,
In 30C, the relay transmission shaft 34 has front and rear bearings 34A, 34B.
The interlocking gears 35A and 35B are fixed to the front and rear of the relay transmission shaft 34 by splines or the like. A clutch body 36 is fixedly fitted to the clutch shaft 31 by a key or other means. Hydraulic pistons 36A, 36
B are fitted in a back-to-back configuration, and oil passages 37A, 37B are formed in the axial direction from one axial end of the clutch shaft 31.
The hydraulic pistons 36A and 36B are respectively supplied with pressure oil via the return springs 38A and 38A.
The clutch plates 39A and 39B can be freely contacted and separated by pressing against 8B.

[0013] The clutch plates 39A, 39B are gears 40A, 40 which are supported on the clutch shaft 31 so as to rotate freely.
B are supported by hubs 41A and 41B having gears B respectively. The gear 40A is engaged with the interlocking gear 35A, and the gear 40B is engaged with the interlocking gear 35B.
A and 35A are for constant speed, and gear groups 40B and 35B are for speed increasing. The opening 30A formed on the lower surface of the gear case 30 is rectangular as shown in FIG. 3, and the rim of the opening 30A is formed in the mounting seat 41,
1, a cover body 42 is provided with a plurality of mounting holes 41A and a positioning hole 41B, and covers from below the clutch body 36 and the like projecting downward from the opening 30A.
And cover 42 is attached to seat 41 with bolt 42A.
When it is attached detachably, it is attached in a state where it is positioned by the knock pin 42B.

As shown in FIG. 3, a first piping member 43 and a second piping member 44 are connected to one end of the oil passages 37A and 37B, respectively, at a cap portion 30D supporting the clutch shaft 31, as shown in FIG. And the first piping member 43 is connected to the first oil passage 3
By supplying the pressure oil to the piston 36A of the constant velocity clutch 32 via the 7A against the spring 38A, the clutch 32 is brought into contact (ON), and the supply of the pressure oil is interrupted to thereby release the spring 38.
A causes the clutch 32 to be disconnected (turned off), while the second piping member 44 supplies pressure oil to the piston 36B of the speed increasing clutch 33 via the second oil passage 37B against the spring 38B. When the clutch 33 is brought into contact (on) and the supply of the pressure oil is interrupted, the clutch 33 is
Of the first and second piping members 43 and 44.
The supply and disconnection of the pressurized oil can be controlled by an electromagnetic solenoid valve (not shown).

A coupling 4 is provided at the front end of the clutch shaft 31.
The front wheel propulsion shaft 46 is joined to the front wheel propulsion shaft device 10 through the front wheel propulsion shaft 5 to form a front wheel propulsion shaft device 10. The front wheel propulsion shaft 46 is covered with a cylinder shaft cover 47. And winding of grass etc. is prevented. In the first embodiment shown in FIGS. 1 to 3, the gears 35A and 35B on the relay shaft 34 and the gears 40A and 40
B is engaged with the gear case 30 to form an assembly. The assembly is provided through an opening 8A formed in the lower abdomen of the tractor body 8, and the gear 35A is engaged with the gear 27 as shown in FIG. The cover body 42 is attached with the bolts 48, and the cover body 42 closes the opening 30A with the bolts 42A and the like. Here, the inspection of the clutches 32 and 33 and the like can be performed by attaching and detaching the cover body 42.

FIGS. 4 and 5 show a second embodiment of the present invention, in which one axial end of a clutch shaft 31 is oil-tight (a circumferential groove is formed on the outer periphery of the clutch shaft 31 at an axial interval). The cap portion which is formed and supported by an O-ring, a lip seal material 52, and the like in the circumferential groove so as to be oil-tight is formed in a hat-shaped cap body 49 separate from the gear case 30. The cap body 49 is spigot-fitted 50 to the shaft end of the clutch shaft 31 and attached to the gear case 30 so that it can be retrofitted with the bolt 51. According to the second embodiment, since the cap body 49 is retrofitted, it is possible to prevent the seal member 52 and the like from being turned over as compared with the first embodiment described above with reference to FIGS. The bottom is even more secure.

Further, in the second embodiment, the cap body 49 is provided with mounting portions 43A, 44A for the pipe members 43, 44, and the pipe members 43, 44 are also provided with the cap body 4.
9 can be retrofitted with mounting portions 43A and 44A.
Since other configurations of the second embodiment are the same as those of the first embodiment, common portions are denoted by common symbols. FIG. 6 shows a main part of a third embodiment of the present invention. In the third embodiment, a hydraulic clutch (a constant-speed hydraulic clutch 32 and a speed-increasing hydraulic clutch 33 in the first embodiment) is used.
) Is mounted on the side surface of the gear case 30. At the time of this mounting, the oil passage 54 is connected to the cap body 49 described in the second embodiment.
A, 54B through the connecting member 54 having the electromagnetic valve 5
3 is attached.

According to the third embodiment, the electromagnetic valve 5
Although a piping member (consisting of a pipe 55A and a block 55B) 55 from the hydraulic pump is required for 3, piping members and couplings from the electromagnetic valve 53 to the oil passages 37A and 37B are not required. In addition, the number of parts and the number of assembly steps can be reduced, and therefore, the number of oil leaks can be reduced. Further, in the third embodiment, since the remotely operated electromagnetic valve 53 is mounted on the upright side surface of the gear case 30 instead of the bottom surface thereof, the ground height of the tractor body 8 is less likely to be reduced.

Further, an oil passage 54 formed in the connecting member 54
Needless to say, A and 54B are connected to hydraulic clutches 32 and 33 through oil passages 37A and 37B formed in the clutch shaft 31 with the pressure oil from the electromagnetic valve 53.
The internal configuration inside the gear case 30 is common to the first embodiment described above. 8 to 10 show the tractor 1,
Particularly, it shows an engine exhaust device of a low-floor type tractor, such as an orchard. The muffler 56 installed in the bonnet 4 has a vertical angle of 20 degrees in each of the vertical direction and the front-rear direction as shown in FIGS. By inclining and arranging it on the upper part of the engine 5, the height of the bonnet 4 is reduced, and agricultural work in a place where fruit trees are overgrown is enabled.
The air cleaner 57 is also installed in the hood 4 in the horizontal direction.

Of course, as shown in FIG. 10, even if the muffler 56 is of a horizontal flat type, it is useful as a low floor type tractor. Further, the exhaust pipe 58 of the muffler 56 is arranged along the side of the engine 5 and its exhaust port 5
It is desirable that the damage to the crop by the exhaust gas be reduced by making the 8A changeable forward, backward, or sideward with the connection fitting 59 as the center. FIG. 11 shows an arrangement in which electromagnetic valves 53 for the hydraulic clutches 32 and 33 are arranged above the tractor body 8 below the driver's seat 14, and furthermore, the valves 53 are covered with a floor sheet 59 so that tree branches can be obtained during orchard work or the like. Of the valve 53 is eliminated, and the drain port of the valve 53 is provided so as to communicate with the inside of the transmission case 6 on the upper surface of the tractor body 8, thereby improving the maintainability of the valve 53. Things.

[0021]

As described above in detail, according to the front wheel drive device for a tractor according to the present invention, the constant-speed hydraulic clutch and the speed-increasing hydraulic clutch can be easily assembled and disassembled, and the maintenance and inspection thereof can be facilitated.

[Brief description of the drawings]

FIG. 1 is an elevational side view showing a front wheel drive device of a tractor and an internal configuration of a transmission system thereof.

FIG. 2 is a cross-sectional view of the front wheel drive device according to the first embodiment.

FIG. 3 is a bottom view with the cover body of FIG. 2 removed.

FIG. 4 is a sectional view of a main part of a second embodiment.

FIG. 5 is a rear view of FIG. 4;

FIG. 6 is a rear view of the third embodiment.

FIG. 7 is a side view of the tractor.

FIG. 8 is a side view showing the engine exhaust device.

FIG. 9 is a plan view of a main part of FIG. 8;

FIG. 10 is a side view of a main part showing another example of FIG. 8;

FIG. 11 is a side view showing an example of mounting a hydraulic clutch valve.

[Explanation of symbols]

 2 Front Wheel 6 Transmission Case 9 Front Wheel Drive 30 Gear Case 30A Opening 31 Transmission Shaft (Clutch Shaft) 32 Constant Velocity Hydraulic Clutch 33 Speed-Increasing Hydraulic Clutch 42 Cover

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshinobu Owada 64 Ishizukitamachi, Sakai City, Osaka Prefecture Inside Kubota Sakai Works (72) Inventor Hideaki Dozono 64 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. In-house F term (reference) 3D043 AA00 AB12 EA02 EA16 EC01

Claims (4)

[Claims] 1. A constant-speed hydraulic clutch and a speed-increasing hydraulic clutch are fitted and supported on a transmission shaft of a front wheel in a gear case, and the gear case is mounted on a lower abdomen of a transmission case constituting a tractor vehicle body. A front wheel drive device for a tractor mounted, wherein an opening is formed on a lower surface side of the gear case, and a cover closing the opening is detachably attached to the gear case. . 2. An oil passage for the hydraulic clutch is formed in the transmission shaft in the axial direction, and a cap body that supports one end of the transmission shaft in an oil-tight manner can be retrofitted to the gear case. The front wheel drive device for a tractor according to claim 1, wherein the front wheel drive device is mounted as a vehicle. 3. The front wheel drive device for a tractor according to claim 1, wherein an electromagnetic valve for turning on / off the hydraulic clutch is mounted on a side surface of the gear case. 4. The front wheel drive device for a tractor according to claim 2, wherein the electromagnetic valve is provided so as to be connected to the cap body.