JP2745136B2 - Farm tractor - Google Patents

Description

The present invention relates to a flat-deck agricultural tractor,
More specifically, the present invention relates to a flat deck agricultural tractor having a belt transmission.

(B) Conventional technology A conventional agricultural vehicle equipped with a belt transmission device is disclosed in, for example, Japanese Patent Application Laid-Open No. 60-177581. This is the seventh
Referring to FIG. 8 and FIG. 8, an engine 2 is mounted on a front portion of a tractor 1 and an output shaft 3 of the engine 2 is mounted.
A variable pulley 5 and a fixed pulley 6 are attached to the first and second pulleys.

Further, the differential device 7 is provided with a fixed case 9, the fixed case 9 is attached to a frame of the vehicle 1, and an input shaft 10 and an output shaft 11 are mounted before and after the fixed case 9,
Bevel gears 12 and 13 are attached to ends of the input shaft 10 and the output shaft 11, and bevel gears 1 meshing with these bevel gears 12 and 13 are provided.
5 is rotatably mounted on a differential case 16 supported on the input shaft 10 and the output shaft 11, and the input shaft 10 and the differential case
The variable pulley 5 and the fixed pulley 6 are attached to the variable pulleys 17a and 17b and the fixed pulley 19, and the belts 20 and 21 are stretched over the variable pulleys 17a and 17b and the fixed pulleys 6 and 19, respectively. ing.

The variable pulley 17b is moved left and right by the operation lever 22 along the input shaft 10 so that the belt 20 is locked to the variable pulleys 17a and 17b with a large diameter or a small diameter. Even if the shaft 3 rotates at a constant speed, a rotational force having a continuously changed rotational speed is taken out from the output shaft 11 of the differential device 7, and this rotational force drives the traveling device at a continuously changed rotational speed. It has become.

(C) Problems to be Solved by the Invention However, the input shaft located at the front center of the vehicle 1
Variable pulleys 17a and 17b are arranged on 10 and fixed pulley 19
Are inserted into the fixed case 9 so that these pulleys
It is difficult to replace belts 20 and 21 of 17a, 17b and 19, and pulley 1
Disassembly and assembly of 7a, 17b and 19 are difficult.

Further, as described above, since the pulleys 17a, 17b, and 19 are located at the center, the front wheel drive shaft is installed below the pulleys 17a, 17b, and 19 in a tractor that drives four wheels. In the case where a shaft-changeable transmission is interposed on the shaft, the height of the space occupied by the power transmission member increases, and it becomes difficult to use the shaft for an agricultural tractor or the like.

Accordingly, an object of the present invention is to provide an agricultural tractor that can secure a high abdominal base height and lower the floor on which a driver's feet are placed, and can easily get on and off.

(D) Means for Solving the Problems The present invention has been made in view of the above circumstances,
For example, referring to FIGS. 1 and 2, the engine (2) is mounted on the front of the fuselage (31), and the driver's seat (34) is arranged on the rear of the fuselage (31). The front part and the rear part are connected by an intermediate case (36), and the upper surface of the intermediate case (36) is placed on a flat floor surface (37) on which the driver's feet are placed.
An input shaft (56) and a PTO interlocking shaft (52) are extended in the longitudinal direction of the body (31) in the middle part of the intermediate case (36), respectively. Driving and driven pulley shafts (61, 62) and (66, 67) extending in the left-right direction of the body (31) on the side of the case (36), and these driving and driven pulley shafts (61, 62) and (66) , 67), a belt transmission (68) is provided by a driving pulley (63, 65) and a driven pulley (69, 70), respectively, and the output shaft (49) of the engine (2) is connected to the belt transmission (68). The travel input shaft (56) and the PTO interlocking shaft (52) are linked via gears (50), (51), (55), and the travel input shaft (56) and the drive pulley shaft (61) , (62) and the driven pulley shafts (66), (67) are connected to each other in a direction perpendicular to the gears (73), and the gear unit (73) and the gear unit (73) are located at the center of the intermediate case (36). While connected to the rear wheel (40) via the output member (80),
Connected to the front wheel drive shaft (91) extending forward of the fuselage,
The interlocking shaft (52) and the front wheel drive shaft (91) are vertically arranged so as to overlap with the drive pulley (63, 65) and the driven pulley (69, 70) in a side view. I do.

(E) Operation Based on the above configuration, the rotational force of the engine (2) passes through the output shaft (49), the gears (50), (51), (55) and the traveling input shaft (56), and passes through the intermediate case (36). ) Is transmitted to the belt transmission (68) provided on both sides of the intermediate case (3).
6) Interlocked with the front and rear drive wheels (39) and (40) via a gear device (73) located in the center of the engine, and from the engine (2) via gears (50) and (51). PTO linked axis (5
The torque input to 2) is transmitted to the rear of the intermediate case (36). For example, as shown in FIG. 5, the PTO interlocking shaft (52) and the front wheel driving shaft (91) overlap with the driving pulley (63, 65) and the driven pulley (69, 70) in side view. By arranging them vertically, the vertical width of the intermediate case (36) is made as small as possible.

In addition, the code | symbol in said parenthesis does not limit a structure at all.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the agricultural tractor 30 has an engine 2 mounted on a front part of a fuselage 31, a seat 33 and a driver's seat 34 disposed above a transmission case 32 at a rear part of the fuselage 31,
The clutch case 35 of the engine 2 and the transmission 32 are connected by an intermediate case 36, and a flat deck 37 is provided on an upper surface of the intermediate case 36 so that a driver can put his / her feet on the flat case 37.

In the drawing, reference numeral 39 denotes a front wheel, 40 denotes a rear wheel, 41 denotes a steering handle, 42 denotes a shift operation lever, and 43 denotes a PTO output shaft.

Next, the power transmission mechanism will be described with reference to FIGS.

Reference numeral 46 denotes a flywheel of the engine 2, and a clutch disk 45 is supported by a clutch case 35 via an output shaft 49 so as to be freely detachable from a clutch 47 attached to the flywheel 46. A drive gear 50 is attached to a rear portion of the output shaft 49, and a PTO gear 51 meshes with the drive gear 50. A PTO shaft 52 of the gear 51 passes through the intermediate case 36, and As shown in FIG. 1, the transmission case 3 is used as the PTO output shaft 43 via the step transmission 53.
2 outside, that is, at the rear of the body 31.

Further, a traveling input gear 55 meshed with the lower side of the PTO gear 51 is supported by the intermediate case 36 integrally with the input shaft 56,
A bevel gear 57 is integrally attached to the rear end of the input shaft 56, and bevel gears 59, 6 meshing with the bevel gear 57 from right and left.
The belt transmission device 6 includes a drive pulley shaft 61, 62 extending in the left-right direction integrally with the drive gear 0, and driven pulley shafts 66, 67 extending in the left-right direction integrally with the side gears 75, 75 of the differential 73 described later.
8 are formed. That is, the drive pulley shafts 61 and 62 are supported by the side wall 36b and the side cover 36a of the intermediate case 36, and the variable pulley 63 and the fixed pulley 65 are mounted on the drive pulley shafts 61 and 62 so as to rotate in opposite directions. Pulley shaft 61, 6
The driven pulley shafts 66 and 67 facing the rear
The driven pulley shafts 66, 67 are provided with a driven variable pulley 69 and a driven fixed pulley 70, and the variable pulleys 63, 69 and the fixed pulleys 65, 70 have a wide V-belt 71,
A V-belt 72 is stretched to form a belt transmission 68.

Reference numeral 73 denotes a differential gear whose side gears 75, 75 are fixed to the inner ends of driven pulley shafts 66, 67.
Pinions 76 and 76 meshing with 5,75 are mounted on a pinion shaft 77 and fixed to a differential case 79. The differential case 79 is mounted on the driven pulley shafts 66 and 67 and output to the differential case 79. The gear 80 is fixed.

A two-stage transmission 81 is connected to the output gear 80 of the differential 73.
Input gear 82 meshes with the output gear 83 of the two-stage transmission 81.
a, 83b are provided, the output gear 83a of which is connected to the rear wheel differential device 85, and both differential shafts 86 of this differential device 85 are reduced in speed and connected to the rear wheels 40, 40 via respective axles. A brake 87 is provided at an end of the differential shaft 86 with respect to a side chamber of the transmission case 32.

Further, a front wheel drive gear 89 is meshed with the lower side of the output gear 83b of the two-stage transmission 81, and a front wheel drive shaft 9 extending forward from the drive gear 89 via bevel gears 90a and 90b.
1 is provided through the intermediate case 36, and the front wheel drive shaft 9
Between the drive pulley shafts 61 and 62 and the differential device 73, a two-stage speed change type front wheel speed increasing device 92 is provided in the intermediate case 36. In FIG. 5, reference numeral 93 denotes a speed change shaft of the speed increasing device 92. The side cover 36a is detachably attached to the intermediate case 36 with bolts 95 and the like. A central chamber 96 and a side chamber 97 are formed in the middle of the intermediate case 36. The pulleys 63, 65, 69, and 70 are connected to the side chambers. 97. As is apparent from FIG. 5, the PTO interlocking shaft 52 and the front wheel drive shaft 91 are disposed above and below the central chamber 96. Further, the PTO interlocking shaft 52 and the front wheel drive shaft 91 are viewed from the side. The driving pulleys 63 and 65 and the driven pulleys 69 and 70 are arranged so as to overlap with each other. Thereby, the vertical width of the intermediate case 36 is made as small as possible.

Next, the variable pulley 63 and the driven variable pulley 69
More specifically, a drive pulley shaft 61 is supported on a side wall 36b of the intermediate case 36 via a mounting member 99, and a fixed cam 100 is mounted on the outer periphery of a cylindrical portion 99a of the mounting member 99. A split piece 63a of the variable pulley 63 is slidably attached to the pulley shaft 61, and a split piece 63b is fixed to an end of the drive pulley shaft 61 so as to face the split piece 63a. Thrust bearing 102 between piece 63a
Is interposed.

Further, the outer split piece 69b of the driven variable pulley 69 is slidably mounted along the outer periphery of the tubular portion of the fixed inner split piece 69a, and the end of the tubular portion of the split piece 69b and the split piece 69a is attached. The movable split piece 69b is urged to approach the fixed split piece 69a with a compression spring 103 interposed therebetween.

Since the embodiment of the present invention is configured as described above,
Clutch 47 provided on flywheel 46 of engine 2
, The rotation of the engine 2 is changed to the output shaft 49, the drive gear
50, through PTO gear 51, PTO shaft 52, two-stage transmission 53,
It is taken out to the PTO output shaft 43 at low second speed. When the two-stage transmission 53 is not connected to any of the high and low gears,
The PTO output shaft 43 stops.

Also, clutch 47, clutch disc 45, output shaft 49,
Drive gear 50, PTO gear 51, travel input gear 55, input shaft 5
The rotation is transmitted to the bevel gear 57 via 6 and the bevel gear 5
From 7, through the bevel gears 59 and 60, rotations that rotate in opposite directions are transmitted to the drive pulley shafts 61 and 62. One of them rotates the left side gear 75 via a variable pulley 63, a wide V-belt 71, a driven variable pulley 69, and a driven pulley shaft 66, and the other is a fixed pulley 65, a V-belt 72, a driven fixed pulley 70, a driven pulley. The right side gear 75 is rotated via the shaft 67.

Then, the output gear 80 rotates at the rotational speed of the average value of the rotational speeds of the side gears 75 that rotate in opposite directions to each other, and this rotation is input to the two-stage transmission 81 via the input gear 82, and the two-stage transmission 81 As a result, the shift range is expanded.

The rotation output from the output gear 83a of the two-stage transmission 81 is transmitted through the rear wheel differential 85 to the left and right differential shafts 86, 86.
To the rear wheel 40 after being decelerated. The brake
87 operates when the rear wheel 40 is braked.

On the other hand, the rotation output from the output gear 83b of the two-stage transmission 81 is transmitted to the front wheels 39 via the drive gear 89, bevel gears 90a and 90b, the front wheel drive shaft 91, the front wheel speed increasing device 92, and the front wheel differential device (not shown). Thus, when the front wheel speed increasing device 92 is set to the low speed stage, the front wheel 39 and the rear wheel 40 rotate at the same peripheral speed, and when the agricultural tractor 30 turns, the front wheel speed increasing device 92 is set to the high speed stage. By setting, the peripheral speed of the front wheel 39 rotates faster than the peripheral speed of the rear wheel 40.

Further, the operation of the continuously variable transmission according to the present invention will be described in detail.When the operation cam 101 is operated and the operation cam 101 moves the split piece 63a of the variable pulley 63 outward by the fixed cam 100,
The wide V-belt 71 moves to the large diameter side. Since the length of the wide belt 71 is constant, the divided piece 69b of the driven variable pulley 69 is pressed by the V-belt 71 and moves outward against the compression spring 103, so that the V-belt 71 has a uniform small diameter. The output rotation speed, that is, the rotation speed of the driven variable pulley 69 is increased more than the input rotation speed, that is, the rotation speed of the variable pulley 63.

Conversely, when the operation cam 101 is operated and the operation lever 101 is moved inward by the fixed cam 100, the V-belt 71
Is rotated by a small diameter, the split piece 69 of the driven variable pulley 69 moves inward due to the urging force of the compression spring 103, and the variable pulley 63 has a small diameter and the driven variable pulley 69 has a large diameter, so that the output rotational speed is reduced. .

Thus, assuming that the driven fixed pulley 70 is rotating at 1000 rotations per minute,
Assuming that the driven variable pulley 69 is at 600 to 2400 revolutions per minute, the sixth
As shown in FIG. 7A, the speed of the differential gear output gear can be shifted between -200 + 700, that is, 200 reverse rotations per minute and 700 forward rotations per minute. And the two-stage transmission 81
Thus, the shift range can be further expanded.

In addition, the fixed pulley 65 and the driven fixed pulley 70 are
63, when the rotation is changed in the same manner as that of the driven variable pulley 69, as shown in FIG.
The speed can be changed from 900 revolutions per minute to reverse 900 revolutions per minute.

Therefore, according to the continuously variable transmission of the present invention described above, the vehicle can be shifted by operating the operation cam 101, so that it is not necessary to operate the clutch 47, and the operation of the vehicle is easy and the engine can be stopped. It is less likely to occur. Also,
In the case of a stop, the operation cam 101 is set to the position of the output rotation speed of zero, the clutch 47 is disengaged, the clutch 47 is brought into contact at the time of departure, and the operation lever may be operated so that the required speed is reduced from zero speed. .

Further, since the pulleys 63, 65, 69, 70 are oriented in the front-rear direction of the vehicle, the PTO shaft, the front wheel drive shaft 91 and the front wheel speed increasing device 92 are vertically moved between the pulleys 63, 69 and 65, 70. Since the intermediate case 36 can be made smaller in the height direction,
As shown, the flat deck 37 of the agricultural tractor 30
And can be lowered in the height H _2, can easily boarding the operator can be further ensured height belly under ground clearance H _1.

Also, pulleys 63, 65, 69, 70 are arranged on both sides, and after attaching and detaching side cover 36a of intermediate case 36, pulleys 63, 65, 69, 70
V-belt 71,7
2 can be easily replaced, and the operation rate of the agricultural tractor 30 can be improved. The pulleys 63, 65, 69, and 70 are supported on both sides to eliminate bending of the shaft and increase the interval between the pulleys, so that the durability of the pulleys 63, 65, 69, and 70 can be improved.

Further, since the fixed cam 100 and the operation cam 101 are accommodated outside the side wall 36b of the intermediate case 36 by the mounting member 99, the width of the intermediate case 36 is reduced by the dimension A in FIG. Easy to dismount, improved disassembly and assembly.

(G) Effect of the Invention As described above, according to the present invention, the belt transmission device (68) is disposed on both sides of the intermediate case (36), and the PT
O The interlocking shaft (52) can pass through the center of the intermediate case (36) to the rear, and the front wheel drive interlocks with the front drive wheel (39) from the gear unit (73) located in the center of the intermediate case (36). Even when a front wheel speed increasing device (92) is interposed between the shaft (91) and the front wheel driving shaft (91), the driving shaft (91) and the front wheel speed increasing device (92) are connected to the belt transmission (68). ), The PTO interlocking shaft (52) and the front wheel drive shaft (91) overlap with the driving pulley (63, 65) and the driven pulley (69, 70) in side view. The vertical width of the intermediate case (36) can be made as small as possible, and the height of the intermediate case (36) for storing these can be made small. The floor (37) of 30) can be formed low, and the height above the belly can be sufficiently secured, and the driver can easily get on and off. .

[Brief description of the drawings]

1 is a side view of an agricultural tractor embodying the present invention, FIG. 2 is a plan view of the power transmission device, FIG. 3 is a side view of FIG. 2, and FIG. Plan view,
FIG. 5 is a longitudinal front view of the intermediate case, FIG. 6 shows the operation of the continuously variable transmission, FIG. 6 (a) shows one having a variable pulley and the other having a fixed pulley, and FIG. (B) shows a vehicle equipped with variable pulleys on both sides, FIG. 7 is a side view of a vehicle that has already been devised, and FIG. 8 is a side view cut along the center plane of the transmission. 2 ... Engine, 30 ... Agricultural tractor, 31 ... Airframe,
34 ... Driver seat, 36 ... Intermediate case, 37 ... Floor surface (flat deck), 39 ... Front drive wheel (front wheel), 40 ... Rear drive wheel (rear wheel), 49 ... Output shaft , 50, 51, 55… gear (drive gear, PTO gear, traveling input gear), 52… PTO interlocking shaft (PTO shaft), 56… traveling input shaft (input shaft), 61, 62… …
Drive pulley shaft, 66, 67: driven pulley shaft, 68: belt transmission device, 73: gear device (differential device).

Claims (1)

(57) [Claims] An engine is mounted on the front of the fuselage, a driver's seat is provided on the rear of the fuselage, and the front and rear of the fuselage are connected by an intermediate case. In a farm tractor having a flat floor surface on which a foot is placed, a traveling input shaft and a PTO interlocking shaft are respectively extended in the center part of the intermediate case in the longitudinal direction of the fuselage. A belt transmission device is provided with a drive and driven pulley shaft extending in the direction, and a drive side pulley and a driven side pulley attached to the drive and driven pulley shaft, respectively. The output shaft of the engine, the traveling input shaft, and the PTO A gear device for interlocking an interlocking shaft via a gear, further interlocking the traveling input shaft and the drive pulley shaft in a direction orthogonal to each other, and positioning the driven pulley shaft at a central portion of the intermediate case; And a front wheel drive shaft extending forward of the fuselage, and the PTO interlocking shaft and the front wheel drive shaft overlap with the drive pulley and the driven pulley in side view. An agricultural tractor, which is disposed vertically above and below.