JPS621789Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering mechanism for a forward-reverse tractor that allows an operator to take forward and reverse positions.

For example, agricultural tractors may be used in forward or reverse motion depending on the working equipment to which they are attached. Therefore, a pair of interlocking shafts, on which the handle shafts are detachably attached, are provided in the steering section in the front and rear, so that the mounting position of the handle shafts can be changed in the direction of travel, so that the steering can always be performed facing the direction of travel.

In order to bring the reverse steering wheel onto the longitudinal centerline of the tractor, it is best to place the lower end of the handle shaft at the attachment point of the driver's seat for forward movement. This is the upper part of the hydraulic system for raising and lowering the towing machine, and since the vertical center line of this hydraulic system approximately coincides with the longitudinal center line of the tractor, the connecting shaft for reversing must be placed through the hydraulic system. , it is difficult to construct, and even if it could be constructed, the structure would be extremely complicated.

This problem can be solved by locating the reversing coupling shaft to the side of the hydraulic system, but the handle shaft attached to the coupling shaft is largely deviated laterally from the longitudinal centerline of the tractor, and the steering A new problem arises in that it becomes difficult to operate.

In view of these various problems, the present invention provides a reverse interlocking shaft on the side of the hydraulic system, and
To provide a steering mechanism for a forward-reverse tractor that can be easily constructed and easily operated by arranging a handle shaft attached to the interlocking shaft in an inclined position so that its upper end is closer to the longitudinal center line of the tractor than its lower end. The purpose is to

A feature of the present invention for achieving this purpose is that there is a hydraulic system for lifting and lowering a working machine, which is disposed at the rear upper part of the vehicle body 1 and whose longitudinal centerline substantially coincides with the longitudinal centerline C of the tractor.
9, and a pair of front and rear steering connecting shafts 38, 54, to which the handle shaft 33 is detachably attached, is provided in front and behind the steering section S. It is provided on the side of the device 29, and the handle shaft 33 is attached to the connecting shaft 54 in an inclined position so that its upper end is located closer to the longitudinal center line C of the tractor than its lower end.

Embodiments of the present invention will be described below with reference to the drawings.

T is a forward-reverse type agricultural tractor, and its body 1 consists of an engine 2, a clutch housing 3, a transmission case 4, etc. as a structure, and the front part of the truck body 1 has a front axle frame 5, a front axle case 6, etc.
The front wheels 7 are supported via a steering gear box 8 mounted on the front axle case 6.
The steering operation is enabled by the lateral movement of the sliding rod 9. The sliding rod 9 can be slid laterally via a rack and pinion mechanism by forward and reverse rotation of the steering shaft 10.

As shown in FIG. 3, the clutch housing 3 and transmission case 4 are integrally formed with a partition wall 11 interposed therebetween, and inside the clutch housing 3 is a double clutch 12 having a traveling clutch and a PTO clutch. Built-in.

The double clutch 12 is connected to the clutch housing 3
The clutch lever shaft 13 is supported laterally on the clutch lever shaft 13, a release fork 14 fixed to the clutch lever shaft 13, a release hub 16 on the propulsion shaft case 15, and the like can be used for intermittent operation with a clutch pedal.

The traveling clutch in the double clutch 12 is connected to the traveling transmission 18 in the transmission case 4 via the traveling main shaft 17, and the PTO clutch is connected to the traveling main shaft 17.
The structure is such that power is transmitted from a PTO cylinder shaft 19 which is rotatably fitted in the shaft to a PTO transmission shaft 21 via a reduction mechanism 20.

The reduction mechanism 20 consists of a small-diameter gear 22 formed on the PTO cylinder shaft 19 and a large-diameter gear 23 fixed to the PTO transmission shaft 21, and is built in a reduction case 24 attached to the bulkhead 11 within the clutch housing 3. has been done. Note that the propulsion shaft case 15 is integrally formed on the cover side of the deceleration case 24.

A brake case 25 containing a built-in brake device and a rear axle case 26 are provided on both rear sides of the tractor body 1.
Each of the rear wheels 27 is provided via the rear wheels 27 and the like. 2
8 is a rear wheel fender, and 29 is a hydraulic system for raising and lowering the work equipment, which is arranged at the rear upper part of the vehicle body 1 as shown in Fig. 2, and its vertical center line (width direction center line) is aligned with the longitudinal center line C of the tractor. 30 is a bonnet that covers the engine 2 and the like. 31F is a forward driver's seat, which is removably attached to a position above the hydraulic system 29 via an attachment part, and is changeably attached to a rear upper position of the bonnet 30, thereby becoming a reverse driver's seat 31R. . A handle 32 is fixed to the upper end of a handle shaft 33, and the handle shaft 33 is rotatably inserted into and supported by a handle post 34.

Reference numeral 35 denotes a front mounting portion for mounting the handle shaft 33 in a forward facing state, and is provided on the upper surface of the clutch housing 3. As shown in FIGS. 3 and 4, the front mounting portion 35 has a mounting base 36 and a connecting shaft 38 rotatably held by the mounting base 36 via a ball bearing 37. The mounting base 36 is installed so as to close the opening 39 on the upper surface of the clutch housing 3, and also has a receiving part 40 into which the handle post 34 is fitted.
are integrally formed. The receiving part 40 is a cylindrical part with a part cut out, and a fastener 41 is detachably provided at the upper end of the receiving part 40.

The fastener 41 is attached to a band 42 as shown in FIG.
and the shaft rod 4 inserted into the free end side of this band 42.
3, a tightening tube 44 fitted onto the shaft rod 43 so as to be slidable in the axial direction, and the shaft rod 43 and the tightening tube 4.
The camshaft 46 is rotatably inserted into and supported by the shaft 43 and has an eccentric cam portion 45 formed in correspondence with the shaft rod 43, and a lever 47 fixed to the camshaft 46. It can be fastened and released by manual operation.

The shaft rod 43 is engaged with a circumferential groove 48 of the handle post 34, and the handle post 34 is provided with a flat portion 49 that allows the shaft rod 43 to pass during removal. The connecting shaft 38 has a spline portion at its upper end, to which a spline cylinder portion 50 at the lower end of the handle shaft 33 is detachably connected. Reference numeral 51 denotes a rear mounting portion for mounting the handle shaft 33 in a rearward position, and the mounting base 52 is mounted on the side of the hydraulic device 29 or on the transmission case 4 on the side thereof, as shown in FIG. Receiving portion 53, connecting shaft 54, ball bearing 5
5. The fastener 56 and the like have the same structure as the front attachment part 35, and the handle post 34, the handle shaft 33, etc. can also be attached to the rear attachment part 51 and the connecting shaft 54. However, the connecting shaft 54 is inclined upward toward the center, and the handle shaft 33 that is coaxially fitted and connected to the connecting shaft 54 has its upper end closer to the longitudinal center line C of the tractor T than its lower end. . As a result, the handle 32 is slightly deviated to the right from the vertical center line C, but this is sufficiently smaller than the deviation of the lower end of the handle shaft 33, and the connecting shaft 54 is shifted slightly to the right from the vertical center line C.
Even if the handle 32 is placed on the side of the tractor T,
It can be operated approximately on the vertical center line. In addition, by increasing the inclination angle of the connecting shaft 54, the handle shaft 3
It is also possible to arrange the upper end of 3 on the vertical center line C.

Reference numeral 57 denotes a relay box, which is installed so as to close an opening 58 formed at the bottom of one side of the clutch housing 3, as shown in FIG. 4, and a bevel gear mechanism 59 is built into this relay box 57. At the same time, a relay shaft 60 in the front-rear direction is rotatably inserted and supported. The relay shaft 60 is a rotational interlocking system 6 consisting of a universal joint 61, an interlocking shaft 62, and a universal joint 63.
4, the steering gear box 8 is interlocked with the steering shaft 10 of the steering gear box 8. The interlocking shaft 62 is disposed below the side of the engine 2 and close to the engine 2.

The relay shaft 60 extends rearward to a large extent, and its rear end is rotatably held by a bearing 65 fixed to the transmission case 4, and is composed of two universal joints 67, 68 and an interlocking shaft 69. It is interlocked and connected to the connection shaft 54 via a rotation interlock system 70. The interlocking shaft 69 is disposed in front of the brake case 9 in a downwardly extending manner, and is rotatably held by a bearing (not shown) mounted on the transmission case 4.

Reference numeral 71 denotes an interlocking shaft, which is disposed diagonally through the opening 58 of the clutch housing 3 on one side of the deceleration case 24 and downwardly downward. 38, the lower ends are interlocked and connected to a relay shaft 60 via a bevel gear mechanism 59 in a relay box 57, respectively. The bevel gear mechanism 59 includes a bevel gear 73 fitted on the lower end of the interlocking shaft 71 and a bevel gear 74 fitted on the relay shaft 60. In addition, each mounting stand 3
Drain holes are formed in the receiving parts 40 and 53 of 6 and 52. Reference numeral 75 denotes steps provided on both left and right sides of the mission case 4, and the relay shaft 60 and the like are arranged below this step 75.

In FIG. 5, the left and right steps 75 correspond to the driver's seat 3.
It is integrally formed with a floor sheet 76 that covers the lower part of the 1st floor and a mudguard 77 that covers the back thereof, and a rear observation window 78 is formed in the mudguard 77, and a transparent plate 79 is provided on this rear observation window 78. ing. 80 is a pair of brake pedals for reversing, 81
82 is a reverse accelerator pedal, and 82 is an operation panel provided in front of the right fender.

The operation panel 82 is provided on the top of a box 83 large enough to close the right side entrance/exit of the tractor T, and displays the main shift lever, width shift lever, creep shift lever, etc., as well as the fuel meter, easy checker, and speedometer. A fuel tank is provided inside the box 82.

This operation panel 82, the bonnet 30
The area separated by the mudguard 77, etc. is the operating section S of the tractor T, and the handle shaft 3
3 and the driver's seat 31 are configured so that their mounting positions can be changed back and forth within this operating section S, allowing the tractor T to be operated in a forward posture and a reverse posture.

In FIG. 1, 85 is a reflector provided on the back of the backrest of the driver's seat 31, and a reflector 86 is also provided at the rear end of the fender 28, but the reflector 86 is disabled when traveling backwards. Therefore, a reflector 85 is provided on the back of the driver's seat 31, which is installed to face rearward, to ensure the safety of the operator when traveling backwards. Incidentally, the reflector 85 is useful as an aid to the reflector 86 even when the vehicle is traveling forward.

In the above configuration, when the vehicle is used for forward travel, the handle 32 is attached to the front mounting portion 35 side as shown by the solid line in FIG. 1, and the driver's seat 31 is attached above the hydraulic device 29. In this case, if the handle post 34 is fitted into the receiving part 40 of the mounting base 36, the spline cylindrical part 50 of the handle shaft 33 is spline-fitted and connected to the connecting shaft 38.
After the shaft 43 is engaged with the circumferential groove 48 of the handle post 34, the shaft 43 is rotated by the lever 47, and the handle post 34 is fixed to the receiving portion 40 by tightening the fastener 41.

After installing the handle shaft 33 in this way,
When the handle 32 is operated, the steering gear box 8 is operated via the handle shaft 33, the connecting shaft 38, the universal joint 72, the interlocking shaft 71, the bevel gear mechanism 59, the relay shaft 60, the universal joint 61, the interlocking shaft 62, and the universal joint 63. The steering shaft 10 rotates forward and backward, and the front wheels 7 can be steered.

When using in reverse, use handle post 3.
4 from the front mounting part 35, and remove the fastener 41.
are removed, these are attached and fixed to the rear attachment part 51, and the handle shaft 33 is connected to the connection shaft 54. On the other hand, the forward driver's seat 31F is removed from above the hydraulic system 29 and mounted above the rear part of the bonnet 30 to form a reverse driver's seat 31R. In this case as well, when the handle 32 is operated, the handle shaft 33 and the connecting shaft 5
4. Since the relay shaft 60 rotates via the universal joint 68, the interlocking shaft 69, and the universal joint 67, the front wheels 7 can be steered via the interlocking shaft 62, the steering shaft 10, etc. as described above.

According to the present invention described in detail above, the connecting shaft 54 connecting the handle shaft 33 when traveling in reverse is connected to the hydraulic device 2.
Since the connecting shaft 54 is located on the side of the handlebar shaft 9, there is no need to provide the connecting shaft 54 through the hydraulic system 29 or the forward driver's seat attachment part, and the arrangement structure is extremely simple and can be easily manufactured. 33 is arranged so that its upper end is closer to the longitudinal center line C of the tractor T than its lower end, so that the handle 32 can be arranged substantially on the longitudinal center line C of the tractor T. Steering operation is also easy, and this also allows the handlebar post 3
4 is not in the center, so visibility is good when monitoring the rear center.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a schematic side view, FIG. 2 is a schematic plan view, FIG. 3 is a sectional view of the clutch housing portion, FIG. 4 is a broken side view of the same, and FIG. 6 is a sectional view taken along the line X--X in FIG. 1, FIG. 6 is a sectional view taken along the Y-Y line in FIG. 4, and FIG. 7 is an enlarged sectional view of the rear mounting portion. 29...Hydraulic system, 31...Driver's seat, 32...
Handle, 33... Handle shaft, 34... Handle post, 35, 52... Mounting part, 38, 54...
...Connection shaft, T...Tractor, S...Operation unit, C...
...Tractor longitudinal center line.

Claims (1)

[Scope of utility model registration request] A hydraulic system 29 for lifting and lowering the working machine is arranged at the rear upper part of the vehicle body 1, and the vertical center line approximately coincides with the longitudinal center line C of the tractor.
The pair of steering connecting shafts 38 and 54 are connected to the steering section S.
In the steering mechanism of a forward-reverse type tractor, which is provided at the front and rear of the
A steering mechanism for a forward-reverse tractor, characterized in that the steering mechanism is mounted on the connecting shaft 54 in an inclined position so that its upper end is located closer to the longitudinal center line C of the tractor than its lower end.