JP2000153788A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable smooth and reliable detachability and maintenance of a transmission belt mechanism, by coaxially interlocking the input end of a first and second transmission belt mechanisms with a drive shaft of an engine portion, and arranging the output end symmetrically centered around the drive shaft above the upper side of a track belt revolving portion. SOLUTION: A drive shaft 76a of an engine 76 is arranged above a left side driving wheel 15 such that the input end side of first and second transmission belts mechanisms 125, 145 are coaxially interlocked with the drive shaft 76a. Also, the output end side of both transmission belt mechanisms 125, 145 are both arranged symmetrically front to back in a position above the upper side of a revolving portion of a track belt 16, with both transmission belt mechanisms 125, 145 respectively centered around the drive shaft 76a. Moreover, both transmission belts 140, 146 are arranged farther to the inside than the track belt 16. As a result, the track belt 16 does not cause difficulties during detachment and maintenance of each of the transmission belts 140, 146 of the first and second transmission belt mechanisms 125, 145, thereby enabling this work to be done smoothly and reliably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working vehicle.

[0002]

2. Description of the Related Art Conventionally, as one form of a working vehicle, a body frame is provided between a pair of right and left crawler traveling parts, and a driving unit, a prime mover unit, and a transmission unit are provided on the body frame, and a prime mover unit is provided. There is a configuration in which the traveling units are linked to each other via a transmission unit.

[0003] The traveling section includes a pair of front and rear driven wheels,
The vehicle includes a drive wheel disposed above a halfway portion between the driven wheels and interlockingly connected to the transmission, and a crawler belt wound between the drive wheels.

[0004] A transmission belt mechanism is interposed between the drive shaft of the motor unit and the input shaft of the transmission unit.

[0005]

However, in the work vehicle described above, the upper turning portion of the crawler belt of the traveling portion is inclined rearward and upward between the front driven wheel and the drive wheel disposed above the front driven wheel. And a transmission belt mechanism interposed between the drive shaft of the motor unit and the input shaft of the transmission unit.
In a side view, since the crawler belt is disposed so as to intersect with the upper turning portion of the crawler belt, when traveling on muddy soil, the crawler belt is disposed below the transmission belt mechanism located below the upper turning portion. There is a problem that the mud and the like adhering to the upper rotating portion adhere to the upper rotating portion in a scattered state, and the transmission function of the transmission belt mechanism cannot be sufficiently secured.

[0006]

Therefore, in the present invention, a vehicle body frame is provided between a pair of right and left crawler-type running parts,
A driving unit, a motor unit, and a transmission unit are provided on the vehicle body frame, and the driving unit is interlocked with the driving unit via a transmission unit.The driving unit includes a pair of front and rear driven wheels,
A drive wheel disposed above the midway between the driven wheels and interlockingly connected to the transmission unit, and a crawler belt wound between the drive wheels, and a transmission unit disposed below the drive shaft of the motor unit A first transmission belt mechanism is interposed between the drive shaft and the input shaft, and a drive shaft of the prime mover unit and a PT
A second transmission belt mechanism is interposed between the drive shaft and the O-shaft. The input ends of the two transmission belt mechanisms are coaxially and operatively connected to the drive shaft of the motor unit, and the output ends of the two transmission belt mechanisms. The present invention provides a work vehicle characterized in that the work vehicle is arranged in the front-rear direction around the drive shaft at a position above the upper turning portion of the crawler belt.

[0007] The first and second transmission belt mechanisms include:
A tension member is provided for each, and the front rotation portions of the first and second transmission belts provided in each transmission belt mechanism can be tensioned by each tension member, and each tension member is placed above the upper rotation portion of the crawler belt. It is also characterized by its arrangement.

Further, according to the present invention, the upper turning portion of the crawler belt is formed so as to be inclined downward forward and downward between the front driven wheel and the driving wheel, and is provided at an upper position of the upper turning portion. It is an object of the present invention to provide a work vehicle characterized by forming an arrangement space for disposing various operation levers and an interlocking connection mechanism interposed between the various operation levers and the transmission unit. .

[0009]

Embodiments of the present invention will be described below.

That is, in the working vehicle according to the present invention, a body frame is provided between a pair of left and right crawler traveling parts, and a driving unit, a motor unit, and a transmission unit are provided on the body frame, and The running unit is interlocked and connected via a transmission unit, and the running unit includes a pair of front and rear driven wheels, a drive wheel disposed above the halfway between the driven wheels and interlocked with the transmission unit, and A first transmission belt mechanism is interposed between the drive shaft of the prime mover unit and the input shaft of the transmission unit disposed therebelow, while the drive shaft of the prime mover unit and A second transmission belt mechanism is interposed between the PTO shaft and an input end of both transmission belt mechanisms. The input end sides of the two transmission belt mechanisms are coaxially and operatively connected to a drive shaft of a motor unit. The output end is above the upper rotating part of the track. At position, they are arranged in distributed form in the front-rear direction around the drive shaft.

In this way, the crawler belt does not hinder the operation of attaching and detaching and maintaining each of the transmission belts of the first and second transmission belt mechanisms from the side of the vehicle body, and these operations are performed smoothly and reliably. be able to.

In addition, since the first and second transmission belt mechanisms are respectively disposed above the upper turning portion of the crawler belt, mud and the like adhering to the upper turning portion fall in a scattered state. However, this mud does not adhere to the first and second transmission belt mechanisms, and maintenance is facilitated from this point as well.

[0013] The first and second transmission belt mechanisms include:
A tension member is provided for each, and the front rotation portions of the first and second transmission belts provided in each transmission belt mechanism can be tensioned by each tension member, and each tension member is placed above the upper rotation portion of the crawler belt. It is arranged.

In this way, even if the mud or the like adhering to the upper rotating portion falls in a scattered state, the mud or the like does not adhere to each tension member, and maintenance is facilitated from this point as well.

The upper rotating portion of the crawler belt is inclined downward and forward between the front driven wheel and the driving wheel, and various operation levers are provided above the upper rotating portion. An arrangement space for disposing an interlocking connection mechanism interposed between the various operation levers and the transmission section is formed.

In this way, the distance between the pair of right and left traveling parts is made as small as possible to reduce the size of the vehicle body, and, in the installation space, various operation levers are arranged at positions where the operator can easily operate. In addition, the interlocking connection mechanism interposed between the various operation levers and the transmission unit can be freely arranged, so that the vehicle body can be made compact and good operability can be ensured at the same time.

[0017]

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

FIG. 1 and FIG. 2 show a work vehicle A according to the present invention. The work vehicle A has a body frame 2 interposed between a pair of right and left crawler-type running parts 1 and 1. On the vehicle body frame 2, a driving unit 3 is disposed at a front part, and a motor unit 4 and a transmission unit 5 are disposed at a rear portion of the transmission unit 1, and a transmission unit 1 and a transmission unit 5 are mounted on the transmission unit 5, respectively. Are interlocked and linked.

As shown in FIGS. 3 and 4, the traveling unit 1 has a front driven wheel 11 attached to a front end of a traveling frame 10 extending in the front-rear direction via an idler fork 12, and a rear driven wheel 11 attached to a rear end. A side driven wheel 13 is mounted via a support bracket 14, and a drive wheel 15 is interlockedly connected to a transmission section 5 described later, and a crawler belt 16 is wound around these driven wheels 11, 13, 15. On the lower side of 10, three crawler belt slippage prevention members 17 are vertically installed at intervals in the front-rear direction, and rolling wheels 18 are attached to each of the crawler belt slippage prevention members 17 respectively. 11a is a front driven wheel support shaft, 13a is a rear driven wheel support shaft, and 15a is a drive shaft.

The drive wheels 15 are, as shown in FIG.
It is located behind the center position C between the front and rear driven wheels 11,13.

In this way, the front side of the crawler belt 16 wound in a triangular shape in a side view can be formed at an acute angle.

Therefore, even when there is soil rising up to a height approximately equal to the minimum ground height on a soft ground, the vehicle can smoothly rush and rush into the raised soil, Performance and work performance can be improved.

The upper rotating portion 16a of the crawler belt 16 is inclined forward and downward between the front driven wheel 11 and the driving wheel 15 so that the upper rotating portion 16a is located above the upper rotating portion 16a. Operating levers provided on the driving unit 3 to be operated, and an interlocking connection mechanism (not shown) interposed between the various operating levers and the transmission unit 5
Is formed in an arrangement space S for disposing them.

In this manner, the pair of right and left traveling parts 1, 1
In addition, the various operation levers are arranged at positions that are easy for the operator to operate in the arrangement spaces S, S, and the various operation levers and the transmission unit 5 are connected to each other. The interlocking connection mechanism interposed therebetween can be freely arranged, so that the compactness of the vehicle body and good operability can be simultaneously achieved.

Further, the front driven wheel 11 is disposed so as to be higher than the rear driven wheel 13 on the ground, and the lower rotating portion 16b of the crawler belt 16 which rotates below the front driven wheel 11 is disposed. A fixed leaving angle θ is formed at the front part.

Thus, on hard ground, the track
The contact length of the tire 16 is reduced, turning resistance is reduced, and the vehicle body is easily turned. Therefore, work performance can be improved.

As shown in FIGS. 3 to 5, the crawler belt slip-off prevention member 17 is formed by attaching an upper end portion of a plate-shaped prevention member main body 17a to the lower surface of the traveling frame 10 via a mounting bracket 19a.
b, and the preventer main body 17a is arranged with its side surface parallel to the extension direction of the traveling frame 10, and
A sliding contact 17b having a downwardly convex arcuate surface is formed at the lower end, and the sliding contact 17b is provided between left and right bifurcated detachment restricting pieces 16c, 16c protruding at the center of the inner surface of the crawler belt 16. They are fitted and arranged. G is a field, U is a ridge.

A cylindrical boss 17c whose axis is oriented in the left-right direction is mounted in the center of the main body 17a in a transversely penetrating manner, and a rolling wheel support shaft 18a is provided with a bearing 18b in the boss 17c. A pair of left and right rolling wheels 18, 18 are attached to the left and right ends of the rolling wheel support shaft 18a, respectively.

In this way, the crawler belt 16 can be prevented from coming off by the crawler belt slippage prevention member 17, and the rolling wheels 18, 18 can be supported by the crawler belt slippage prevention member 17, so that the rolling wheel 18 , 18 can be simplified.

In addition, the structure of the crawler belt slippage prevention member 17 can be simplified, and the effect of preventing the crawler belt slippage can be satisfactorily ensured.

As shown in FIGS. 1, 2 and 4, the body frame 2 is provided between a pair of front and rear portions of a pair of left and right running frames 10, 10 extending in the front-rear direction. The left and right connecting frames 20 and 21 are laid horizontally, and a pair of left and right front frames
Attach the lower end of both front frames 22,22
To the front and upward, and a horizontal frame 23 extending in the left-right direction is placed between the upper ends of both front frames 22 and 22.
A pair of left and right seat pivot brackets 24, 24 project upward from the center of the horizontal frame 23, while the lower ends of a pair of left and right rear frames 25, 25 To the rear frame 25, 2
5, a guard frame 26 formed in a rectangular frame shape in a plan view is laterally formed between the upper end of the frame 5 and the left and right ends of the horizontal frame 23. 27 is a guard frame stay.

A mounting table 28 projects from the center of the front wall of the left and right connecting frame 20 on the front side so as to protrude forward, and a battery 29 and a fuel tank 30 are mounted on the mounting table 28.

A front support 31 for supporting the front end of the transmission section 5 is provided at the rear center of the front left and right connecting frame 20.
Has been established.

At the center of the rear left and right connecting frame 21,
A pair of right and left motor support columns 32, 32 for supporting the motor unit 4 are provided upright.

A PTO shaft case 33 extending in the left-right direction is suspended between the middle portions of the pair of left and right rear frames 25, 25,
The PTO shaft 34 is rotatably inserted into the PTO shaft case 33, and the front end of the lifting link 35 is pivotally supported on the outer peripheral surface of the central portion of the PTO shaft case 33, and the lifting link 35 is connected to the PTO shaft.
A vertically movable cylinder 36 is provided between the middle part of the lifting link 35 and the center of the rear side frame forming body 26c of the guard frame 26. Then, the rear end of the elevating link 35 can be moved up and down by the elevating cylinder 36, and a hitch body 37 for connecting various working machines is attached to the rear end of the elevating link 35. 38
Is a side cover body.

In this way, the PTO shaft case 33 can be reliably supported with a simple structure.

Moreover, the weight of the vehicle body can be reduced by simplifying the structure of the body frame.

Further, since the hitch body 37 is attached to the PTO shaft case 33, a working machine can be attached via the hitch body 37.

Then, the load of the working machine is changed from the hitch body 37 → P
TO shaft case 33 → rear frame 25, 25 → left and right connecting frame 20 → left and right running frame 10, 10
Even when the work machine is raised and lowered, the vertical swing of the front and rear portions of the vehicle body can be reduced.

As shown in FIGS. 1, 2 and 6, the operating section 3 has a floor (not shown) stretched in the front half of the guard frame 26, and a handle column is mounted on the front of the floor. 40 standing,
A handle support shaft 41 extending vertically is inserted into the handle column 40, and a rotatable handle (steering wheel) 42 is mounted on an upper end of the handle support shaft 41, and a lower end portion of the handle support shaft 41 is provided. And mission unit 5 described later
And a forward / backward switching lever 44 is attached to the lower part of the left side wall of the handle column 40, and the forward / backward switching lever 44 is connected to the transmission unit 5 which will be described later.
The forward / reverse switching arm 162 provided on the connecting rod mechanism 45
And a brake pedal 46 is attached to the front part of the floor, and the brake pedal 46 and a brake operation arm 166 provided on the transmission unit 5 described later are linked via an interlock wire 47. Connected.

The seat 48 is located behind the handle 42.
Are mounted via the seat pivot brackets 24, 24, and various operation levers are disposed on the left and right sides of the seat 48.

That is, the shift lever 49 is located on the left side of the seat 48.
And the transmission lever 49 is moved to the transmission section 5 described later.
The main transmission unit 97 and the auxiliary transmission unit 104 provided inside are interlockingly connected via an interlocking connection mechanism, and the work implement elevating lever 50, the hydraulic lock lever 51, and the plowing depth adjusting lever 52 are The levers 50, 51, 52
Is linked to a valve mechanism (not shown) for controlling the lifting cylinder 36 via an interlocking connection mechanism. Further, a PTO shaft clutch lever 53 is provided outside the work implement lifting lever 50.
And the PTO shaft clutch lever 53 is operatively connected to a tension arm 150 of a second transmission belt mechanism 145 described later.

Here, the structure of the cam mechanism 43 is shown in FIGS.
This will be described with reference to FIG.

That is, the cam mechanism 43 is provided with a guard frame.
26 and the guard frame 26
A shaft support 55 is laid between the left and right frame forming bodies 26b, 26b and the connecting horizontal frame 54 laid horizontally between the front portions thereof, and a shaft support case 56 is erected on the coaxial support 55. , Coaxial support case
The lower end 41a of the handle support shaft 41 projects downward below the shaft support 55, and the lower end 41a of the handle support shaft 41 is supported by the cam support cylinder 57. Are connected together by connecting pins 178, and the neutral detecting cam 58 is successively connected to the cam supporting cylinder 57 from the lower side to the upper side.
And the left-turn detection cam 59 and the right-turn detection cam 60 are coaxially mounted at a fixed interval. 170 is a movable side spring retaining piece, 171 is a fixed side spring retaining piece, and 172 is a double spring retaining piece.
It is a torque spring for neutral restoration interposed between 170,171,
The torque spring 172 elastically urges the handle 42 to return to the neutral position for steering left and right.

The neutral detection cam 58 has a partially concave non-working surface 58a and a non-working surface 58a
An operating surface 58b having a diameter larger than that of the entire surface and substantially the entire circumference is formed.

The left turning detection cam 59 has a disk-shaped peripheral surface having a right half non-working surface 59a and a left half half working surface 59b.
The non-working surface 59a is formed to have a uniform small-diameter surface, while the working surface 59b is formed to have a gradually larger diameter along the circumferential direction than the non-working surface 59a.

The right turning detecting cam 60 is a left turning detecting cam.
It is formed in a shape symmetrical to the line 59, and a left half non-working surface 60a and a right half working surface 60b are formed on the disk-shaped peripheral surface.

The shaft support 55 has an arm / wire support 61.
A cam follower arm 62 for neutral detection, a cam follower arm 63 for left turn detection, and a cam follower arm 64 for right turn detection are coaxially mounted on the arm and wire support 61 via an arm support shaft 65. And the front ends of the neutral wire 66, the left turn wire 67, and the right turn wire 68 connected to one end of each of the arms 62, 63, 64, respectively.

At the other end of each of the arms 62, 63, 64, cam contact rollers 69, 70, 71 are rotatably mounted, respectively.
Each cam contact roller 69, 70, 71 is in contact with the peripheral surface of each cam 59, 60, 61.

Each wire 66, 67, 68 is an outer wire
66a, 67a, 68a and inner wires 66b, 67b, 68b inserted into the outer wires 66a, 67a, 68a.

Then, the inner wire 66 of the neutral wire 66
“b” is an interlocking connection between one end of the cam follower arm 62 for neutral detection and a brake operation arm 73 of a turning brake unit 72 provided in the transmission unit 5 described later.

The inner wire 67 of the left turn wire 67
b is a hydrostatic continuously variable transmission that is linked to one end of a left-turn detection cam driven arm 63 and a mission unit 5 described later.
The left side connecting piece 75a of the trunnion arm 75 provided at 74 is interlockingly connected.

The inner wire 68b of the right turning wire 68 is
One end of the right rotation detection cam driven arm 64 and the right connection piece 75b of the trunnion arm 75 are linked and connected. 17
6,177 is an outer wire receiver.

In this way, when the handle 42 is in the neutral state of left-right steering (straight running operation position), the cam contact roller 69 of the neutral detection cam driven arm 62 is placed on the non-operation surface 58a of the neutral detection cam 58. The cams 59 and 60 for left and right turning detection are in contact with each other in the
Cam contact roller 7 of cam driven arm 63, 64 for right turn detection cam
0,71 abuts.

In this state, any of the inner wires 66
b, 67b, 68b are not pulled, and the turning brake
Reference numeral 72 denotes a state in which the output shaft 74b of the hydrostatic continuously variable transmission 74 described later is braked.

Then, the steering wheel located at the neutral position for the left and right steering.
When the turning operation is performed in the left turning direction, the three cams 58, 59, and 60 interlockingly connected via the handle support shaft 41 are also integrally turned in the same direction.

As a result, the non-operation surface 58 of the neutral detection cam 58
The cam contact roller 69, which has been in contact with a, rolls and contacts the working surface 58b of the neutral detection cam 58, and the neutral detection cam driven arm 62 is rotated, and the arm 62 is connected to the inner wire 66b.
, The turning brake unit 72 operates via the brake operation arm 73 to release the brake braking.

At the same time, the non-operating surface 59 of the left turning detection cam 59
The cam contact roller 70, which has been in contact with a, rolls and contacts the working surface 59b of the left-turn detection cam 59, and the left-turn detection cam follower arm 63 is rotated.
By pulling b, the rotational speed on the left turning side in the turning power transmission system H of the hydrostatic continuously variable transmission 74 is gradually increased through the left connecting piece 75a of the trunnion arm 75, and the right turning is performed. Gradually reduce the number of revolutions on the side.

The non-operating surface 60a of the right turning detection cam 60
The cam contact roller 71, which has been in contact with
60a Rolling and abutting on the upper, cam driven arm for right turn detection
63 is not rotated, and the arm 63 is
It does not pull 67b.

Accordingly, the speed of the right traveling unit 1 is gradually increased according to the turning operation angle of the steering wheel 42 in the left turning direction.
The left traveling unit 1 is decelerated, and the vehicle body turns leftward.

By increasing the turning operation angle of the handle 42, a pivot turn in which the vehicle body turns while the left traveling unit 1 is stopped, and further, the left traveling unit 1 is opposite to the right traveling unit 1 It can also perform a pivot turn in which the vehicle turns in response to running in the reverse direction.

When the steering wheel 42 is turned in the right turning direction, the respective operating parts operate in the opposite direction, and the vehicle body is turned to the right. Also in this case, the pivot turn and the spin turn of the vehicle body can be performed in the same manner as described above, depending on the magnitude of the turning operation angle of the handle 42.

Further, since the three cams 58, 59 and 60 are coaxially mounted below the handle support shaft 41, the handle support shaft 41 functions as a cam support shaft to eliminate so-called rattling. As a result, high-precision operation can be performed, operability can be improved, and these cams 58, 59, 60 are compactly arranged by effectively utilizing the dead space under the handle shaft 41. can do.

Furthermore, since the brake operation arm and the trunnion arm are configured to operate in conjunction with the pulling operation of each of the inner wires 66b, 67b, 68b, the brake operation arm 73 and the trunnion arm 75 can be accurately connected. The wires 66, 67, and 68, which can be operated and have a high degree of freedom in arrangement, can be arranged compactly.

The engine unit 4 includes an engine 76 and the engine 76
A radiator, an air cleaner, and the like (not shown) are provided near 76.

As shown in FIGS. 1 and 2, the transmission section 5 includes a front support column 31 erected at the center of the rear side of the front left and right connecting frame 20 and a rear portion of the left and right traveling frames 10, 10. It is installed between a pair of left and right rear support columns 77, 77, and a chain case 78 is interlockingly connected to the left side of the transmission unit 5, while a hydrostatic stepless transmission for turning is mounted on the right side. 74 (hereinafter referred to as “HST”).

Then, the mission unit 5 is provided with the components shown in FIGS.
As shown in FIG.
The shafts 81 to 89 are supported in parallel, the input side of the forward clutch 90a is fitted in the middle of the first shaft 81, and the end of the first shaft 81 is
An input side of a reverse clutch 90b loosely fitted in the middle of the second shaft 82 through a meshing gear 91, and a hydraulic pump 92
And the second shaft 82, which is the output side of the forward clutch 90a and the output side of the reverse clutch 90b, is linked to the third shaft 83 via the second meshing gear 93, and The power transmission of the reverse clutches 90a and 90b is configured to be exclusively selectable, so that the drive direction can be switched between forward and backward. 80a is a drive shaft case.

Here, the forward and reverse clutches 90a, 90b are
Shifter spindle 160 laid on the front in the transmission case 80
At the same time, a clutch on / off shifter 161 is mounted, and the clutch on / off shifter 161 is connected with the forward clutch 90a and disengaged with the reverse clutch 90b in conjunction with the rotation of the shifter support shaft 160 in one direction. The forward clutch 90a is disengaged in conjunction with the rotation in the other direction, and the reverse clutch
90b is connected so that it can switch between forward and reverse.

A forward / reverse switching arm 162 is attached to the left end of the shifter support shaft 160, and a forward / reverse switching lever 44 is interlocked to the front / reverse switching arm 162 via a connecting rod mechanism 45. I have.

The third shaft 83 is an input shaft of the HST 74.
74a and a fourth shaft 84 which is an input shaft of the main transmission 97 via a third meshing gear 96. The fourth shaft 84 is connected to dogs 98, 98 at both ends and a central portion. A slider 100 integrally formed with the second speed driving gear 99 is slidably and non-rotatably fitted in the axial direction, while the fourth shaft 84 and the main transmission portion 97 are fitted.
The first and third speed meshing gears 101 and 102 which are always meshing are interposed between the fifth shaft 85 which is the output shaft of the motor, and the second mesh passive speed gear 103 which is sliding meshing is fitted to the fifth shaft 85. The output rotation speed of the main transmission 97 can be switched in three stages by sliding the slider 100.

The main transmission 97 is connected in series with an auxiliary transmission 104, and the auxiliary transmission 104 is connected to the fifth shaft 85.
High and low speed meshing gears 105 and 106 are interposed between the shaft and the sixth shaft 86 as an output shaft of the auxiliary transmission portion 104, and the sixth shaft 86 is slidable in the axial direction.
By the sliding of the slider 107 fitted non-rotatably, the output rotation speed of the sub-transmission portion 104 can be shifted in two stages of high and low speeds with a neutral in between.

As described above, the forward / reverse clutches 90a, 90b
, A main transmission section 97 for three-speed shifting, and an auxiliary transmission section 104 for two-speed shifting.
Are linked in series in an interlocking manner, so that a six-step forward / backward shift operation can be finally performed.

The sixth shaft 86 is operatively connected to a seventh shaft 87 via a chain interlocking mechanism 108, and left and right sun gears 110 and 111 fitted to the left and right ends of the seventh shaft 87, respectively.
Left and right cages 112 and 113 connected to the left and right drive shafts 15a and 15a having the same axis as 87, a plurality of left and right planetary gears 114 and 115 respectively mounted on the left and right cages 112 and 113, and an output shaft 74b of the HST 74 interlockingly connected. Left and right ring gear 11
6 and 117 constitute left and right planetary gear mechanisms 118 and 119. The left and right planetary gear mechanisms 118 and 119 transmit the right and left sun gears 110 and 111 by the mechanical linear power transmission system M constituted by the gear type transmission and the meshing gear. Rotational power and the left and right ring gears from HST74 of the turning power transmission system H described later
And the rotational power transmitted to the left and right driving shafts 15 and 15 fitted to the left and right drive shafts 15a and 15a via the left and right planetary gears 114 and 115 and the right and left cages 112 and 113, respectively. They are communicated individually.

Here, a stopping brake portion 165 is provided at the left end of the sixth shaft 86, and the brake pedal 46 is attached to a brake operating arm 166 attached to the stopping brake portion 165.
Are interlockingly connected via an interlocking wire 47.

The output shaft 74b of the HST 74 has the same output shaft
A forward / reverse rotation splitting mechanism 120 for transmitting the rotational speed of the rotation gear 74b complementarily to the left and right ring gears 116 and 117 is interlocked and connected to the downstream side of the turning brake unit 72. The eighth shaft 88 is operatively connected to the output shaft 74b of the ninth shaft 89 via a reduction gear group 121, and the eighth shaft 88 is operatively connected to the ninth shaft 89 via a first intermediate meshing gear 122. Left and right output gears 123 and 124 are fitted to the left and right ends, respectively, and the left output gear 123 and the left ring gear 116 are interlocked and connected via two idle gears (not shown) arranged in series. The right ring gear 117 and the right ring gear 117 are operatively connected to each other via one idle gear 79, and while the absolute values of the rotation speeds are equal, the rotation in the same direction as the ninth shaft 89 is transmitted to the left ring gear 116, The right ring gear 117 has a ninth shaft 89
The rotation in the opposite direction is transmitted.

The first input shaft of the mission unit 5
One end of the shaft 81 is protruded from the left side wall of the transmission case 80, the lower end of the chain case 78 is interlockedly connected to the protruded end, and the chain case 78 is extended upward, and the upper end of the chain case 78 is extended. And the drive shaft 76a of the engine 76 are operatively connected via a first transmission belt mechanism 125, while the handle 42 is operatively connected to the trunnion arm 75 of the HST 74 via a cam mechanism 43, and the handle 42 is turned. The gear ratio of the HST 74 can be changed steplessly in the forward and reverse directions according to the operation angle. 126 is the shifter of the main transmission 97, 127
Reference numeral 128 denotes a shifter of the auxiliary transmission unit 104, and reference numeral 128 denotes a front PTO shaft case for taking out power to the front outside.

The turning brake unit 72 will now be described. As shown in FIG. 11, the turning brake unit 72 has a cylindrical input shaft 130 spline-fitted to the output shaft 74b of the HST 74, and A wet-type multi-plate brake 131 is interposed between the input shaft 130 and the transmission case 80, and an axial operation piece 132 is disposed near the multi-plate brake 131.
By rotating 132 around its axis, the wet multi-plate brake 131 can be slid in the axial direction of the cylindrical input shaft 130 to perform a brake braking action.
The lower end of the action piece 132 projects outward from the lower part of the transmission case 80, and
Attach the handle 42 to the brake operation arm 73
Are connected to each other via a handle support shaft 41, a neutral detection cam 58, a neutral detection cam driven arm 62, and a neutral wire 66.

Further, an output gear 133 is attached to the cylindrical input shaft 130, and a reduction gear group 121 is meshed and connected to the output gear 133.

In this manner, the steering brake 42 can be set to the H
The turning power transmission system H can be brought into a stopped state by braking the output shaft 74b of ST74, and as a result, only the straight traveling power transmission system M can be operated, and the straight traveling power transmission system M Good straightness can be ensured.

Since the turning brake unit 72 is provided on the output shaft 74b of the HST 74 provided on the upstream side of the turning power transmission system H, the output shaft 74b can be braked directly with a small torque. Thus, even if the capacity of the turning brake unit 72 is reduced, the power transmission of the turning power transmission system H can be reliably stopped.

Further, by turning the steering wheel 42 in one of the left and right directions from the left and right steering neutral position, the brake braking of the turning brake portion 72 is released, and the vehicle body can be turned in the rotation direction. .

Therefore, the steering operability of the vehicle body, particularly the straight traveling operability, can be improved.

Further, since the turning brake unit 72 uses the wet multi-plate brake 131, the turning brake unit 72 is used.
The axial width of the 72 can be reduced, and the 72 can be disposed in the transmission case 80 without any trouble.

With the above-described configuration, the power from the engine 76 is shifted in six stages in the forward and backward directions to be transmitted to the left and right traveling units 1 and 1, and the HST 74 is changed according to the operating angle of the steering wheel 42.
And the driving speeds of the left and right traveling units 1 and 1 are changed so that the working vehicle A
Can be turned.

In this embodiment, since the input shaft 74a of the HST 74 is connected to the output side of the reverse clutch 90b, the switching of the forward / reverse clutch 90a, 90b can be performed without operating the handle 42. At the same time, the output rotation direction of the HST 74 is switched, so that the operation direction of the steering wheel 42 and the turning direction of the work vehicle A maintain a constant relationship, and the turning operation can be performed with almost the same feeling as the steering operation of the wheel type vehicle. It can be carried out.

[0086] The chain case 78 is shown in Figs.
As shown in FIG. 1, a case main body 78a is formed by extending in the vertical direction, and a transmission input shaft 78b is provided on an upper portion of the case main body 78a, and the transmission input shaft 78b and the first shaft of the transmission unit 5 are provided.
81 and the transmission chain 78c between the sprockets 78d and 78
winding through e.

The chain case 78 is shown in FIGS.
As shown in the figure, a transmission input shaft 78b is formed inside the crawler belt 16 of the left traveling unit 1 so as to be located above the upper turning part 16a of the crawler belt 16 and further above the drive wheel 15. One end of the transmission input shaft 78b projects rightward from the case body 78a, and a first transmission belt mechanism 125 is interposed between the same end and the drive shaft 76a of the engine 76.

That is, as shown in FIGS. 1, 10, and 11, the first transmission belt mechanism 125 is provided between the drive shaft 76a of the engine 76 and the transmission input shaft 78b.
Are wound around pulleys 141 and 142, and a tension roller 143 is attached to the first transmission belt 140.
4, a tension member 153 is formed as a tension member for tensioning the first transmission belt 140 by the tension roller 143.

The tension member 153 presses the tension roller 143 against the front rotating portion 140a (the loose side) of the first transmission belt 140.

In this manner, the upper rotating portion 16a of the crawler belt 16
By contacting the tension roller 143 with the front rotating portion 140a which is farther away, scattering and adhesion of mud and the like to the tension member 153 are prevented.

The drive shaft 76a of the engine 76 and the PT
A second transmission belt mechanism 145 is provided between the left end of the O-shaft 34 and the O-shaft 34.
Is interposed.

That is, as shown in FIG. 1, the second transmission belt mechanism 145 includes a drive shaft 76a of the engine 76 and the PTO shaft 34.
Of the second transmission belt 146 between the pulley 147 and
A tension member is wound around the second transmission belt 148 so that a tension roller 149 can freely advance and retreat via a tension arm 150, and the second transmission belt 146 is tensioned and relaxed by the tension roller 149. Is formed as the tension clutch 154.

[0093] The driving section 3 disposed in front of the tension clutch 154 has a PTO as a clutch operating means.
A shaft clutch lever 53 is provided, and a tension arm 150 is operatively connected to the PTO shaft clutch lever 53 via a connection link mechanism (not shown).
The tension roller 149 attached to the second transmission belt 146
Is configured to advance and retreat with respect to the front-side rotating portion 146a (the slack side) of the camera.

Thus, the PTO shaft clutch lever
By contacting the tension roller 149 with the front rotating portion 146a closer to 53, the structure of the connecting link mechanism can be simplified and the transmission accuracy of the connecting link mechanism can be ensured well.

Further, since the tension clutch 154 is disposed at a position higher than the upper turning portion 16a of the crawler belt 16, scattering and adhesion of mud and the like to the tension clutch 154 can be prevented.

Here, the drive shaft 76a of the engine 76 is
When viewed from the side as shown in FIG. 3, it is disposed above the left driving wheel 15, and the input ends of the first and second transmission belt mechanisms 125 and 145 are coaxially and operatively connected to the drive shaft 76a.
The output end sides of the transmission belts 125 and 145 are arranged above and below the upper turning portion 16a of the crawler belt 16, and the transmission belt mechanisms 125 and 145 are respectively arranged in the front-rear direction around the drive shaft 76a.

Further, both transmission belts 140, 146 of both transmission belt mechanisms 125, 145 are arranged on the inner side of crawler belt 16 in plan view.

In this way, the crawler belt 16 does not hinder the attachment and detachment of the transmission belts 140 and 146 of the first and second transmission belt mechanisms 125 and 145, and these operations can be performed smoothly and reliably. it can.

In addition, the first and second transmission belt mechanisms 125, 14
5 is disposed above the upper turning portion 16a of the crawler belt 16, so that even if the mud or the like adhering to the upper turning portion 16a falls in a scattered state, the mud or the like adheres. Maintenance is also easy from this point.

HST provided upstream of turning power transmission system H
As shown in FIG. 2, the HST case 74 is formed by extending the HST case 151 in the front-rear direction, the front end side is located upward, and
Transmission case with the rear end side down
A space 152 is formed at the lower part on the front side of the HST case 151 so as to be connected to the right side wall of the HST case 80.

In this manner, the front and rear width and height of the vehicle body can be set as small as possible.
When the TO shaft case 128 is connected to the lower side of the mission case 80, the TO shaft case 128 is also connected to the right side wall of the transmission case 80 in a forwardly inclined posture.
Interference with the front PTO shaft case 128 can be avoided.

Further, on the right side wall of the mission case 80,
A work machine elevating pump 92 is connected to the HST 74 in front of and above the HST 74, and a drive shaft 92a of the work machine elevating pump 92 is provided.
, Input and output shafts respectively arranged at the front and rear of HST74
74a, 74b and are arranged on substantially the same straight line L.

In this way, the HST 74 and the work implement elevating pump 92 can be compactly arranged in the right side wall of the transmission case 80.

FIG. 13 shows a crawler belt slippage prevention member 17 as another embodiment. The crawler belt slippage prevention member 17 extends a sliding contact member 17b formed at the lower end portion of the prevention member main body 17a in the front-rear direction. It is shaped like a boat bottom.

In this manner, the effect of preventing the crawler belt from slipping off by the sliding member 17b can be further enhanced.

[0106]

According to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, a vehicle body frame is provided between a pair of right and left crawler-type traveling units, and an operating unit, a motor unit, and a transmission unit are provided on the vehicle body frame, and the traveling unit is mounted on the motor unit. Parts are interlockingly connected via a transmission part, and the traveling part includes a pair of front and rear driven wheels, a drive wheel disposed above the midway between the two driven wheels and interlockingly connected to the transmission part, and a winding between these driving wheels. A first transmission belt mechanism is interposed between the drive shaft of the prime mover unit and the input shaft of the transmission unit disposed therebelow, while the first transmission belt mechanism is disposed below and below the drive shaft of the prime mover unit. A second transmission belt mechanism is interposed between the PTO shafts and the input end sides of the two transmission belt mechanisms are coaxially and operatively connected to a drive shaft of the prime mover unit, and outputs of the two transmission belt mechanisms are provided. The end side is located above the upper turning part of the crawler belt. Since the belts are arranged in the front-rear direction around the drive shaft, the crawler belts are required when attaching / detaching / maintaining the transmission belts of the first and second transmission belt mechanisms from the side of the vehicle body. These operations can be performed smoothly and reliably without any hindrance.

In addition, since the first and second transmission belt mechanisms are disposed above the upper turning portion of the crawler belt, mud and the like adhering to the upper turning portion fall in a scattered state. However, this mud does not adhere to the first and second transmission belt mechanisms, and maintenance is facilitated from this point as well.

According to the second aspect of the present invention, the first and second power transmission belt mechanisms are provided with tension members, respectively, and the first and second power transmission belt mechanisms are provided on the respective power transmission belt mechanisms by the respective tension members. The moving part can be tensioned,
Since each tension member is disposed above the upper turning portion of the crawler belt, even if mud or the like adhered to the upper turning portion falls in a scattered state, the mud or the like is applied to each tension member. There is no sticking, which makes maintenance easier.

According to the third aspect of the present invention, the upper turning portion of the crawler belt is inclined downward and downward toward the front between the front driven wheel and the driving wheel, and is located above the upper turning portion. In the position, there is formed an arrangement space for arranging various operation levers and an interlocking connection mechanism interposed between the various operation levers and the transmission unit, so that a distance between a pair of right and left traveling units is provided. In the installation space, the operating lever is arranged at a position where the operator can easily operate, and an interlocking mechanism is interposed between the operating lever and the transmission unit. Can be freely arranged, and compactness of the vehicle body and good operability can be simultaneously achieved.

[Brief description of the drawings]

FIG. 1 is a side view of a working vehicle according to the present invention.

FIG. 2 is a plan view of a body frame of the work vehicle.

FIG. 3 is a side view of a traveling unit.

FIG. 4 is an explanatory sectional front view of the traveling unit.

FIG. 5 is a side view of a crawler belt slippage prevention body.

FIG. 6 is an explanatory view of a cam mechanism.

FIG. 7 is a bottom view of the cam mechanism.

FIG. 8 is a sectional bottom view of the cam mechanism.

FIG. 9 is a left side sectional view of the transmission unit.

FIG. 10 is a cross-sectional plan view of a transmission section showing a straight-moving power transmission system.

FIG. 11 is a cross-sectional plan view of a transmission section showing a turning power transmission system.

FIG. 12 is a right side view of the mission unit.

FIG. 13 is a side view of a crawler belt slippage prevention body as another embodiment.

[Explanation of symbols]

 A Work vehicle 1 Running unit 2 Body frame 3 Operation unit 4 Engine unit 5 Transmission unit

Continuation of the front page (72) Inventor Takao Oniki 428 Enami, Okayama City, Okayama Prefecture F-term (reference) 2B041 AA02 AA07 AB05 CA03 CA14 EA04 3D039 AA03 AB11 AB22 AC05 AC21 AC33 AD06 AD11 AD25 AD54 3D042 AA05 AB10 AB11 BA02 BB03 BD04 BD08 3D052 BB08 BB11 DD01 DD03 EE01 FF01 GG03 HH01 JJ00 JJ21 JJ31

Claims (3)

[Claims] 1. A vehicle body frame (2) is provided between a pair of left and right crawler type traveling parts (1, 1), and an operation part (3), a motor part (4) and a transmission part are provided on the body frame (2). (5), and the running section (1, 1) is interlockedly connected to the motor section (4) via a transmission section (5), and the running section (1) has a pair of front and rear driven wheels (11, 13) and both driven wheels
(11,13)
Drive wheels (15) linked to (5) and these drive wheels (11,13,1)
5) a crawler belt (16) wound therebetween, and a first transmission belt between a drive shaft (15) of a motor unit (4) and an input shaft of a transmission unit (5) disposed therebelow. Mechanism (125)
On the other hand, a second transmission belt mechanism (145) is interposed between the drive shaft (76a) of the prime mover section (4) and the PTO shaft (34) disposed below the drive shaft (76). The input end of the mechanism (125, 145) is coaxially linked to the drive shaft (76a) of the motor unit (4), and the output end of the two transmission belt mechanisms (125, 145) is connected to the track (16). A work vehicle characterized by being arranged in a front-rear direction around a drive shaft (76a) at a position above an upper rotating part (16a). 2. A tension member is provided for each of the first and second power transmission belt mechanisms (125, 145), and the first and second power transmission belts (140, 146) are provided on each of the power transmission belt mechanisms (125, 145) by the tension members. 2. The work according to claim 1, wherein each of the tension members is disposed above the upper turning portion (16a) of the crawler belt (16) so that the front turning portion (140a, 146a) can be tensioned. car. 3. A vehicle body frame (2) is provided between a pair of left and right crawler-type traveling parts (1, 1), and an operating part (3), a motor unit (4), and a transmission part are provided on the body frame (2). (5), and the running section (1, 1) is interlockedly connected to the motor section (4) via a transmission section (5), and the running section (1) has a pair of front and rear driven wheels (11, 13) and both driven wheels
(11,13)
Drive wheels (15) linked to (5) and these drive wheels (11,13,1)
5) A crawler belt (16) wound between the crawler belts (16), and the upper rotating part (16a) of the crawler belt (16) moves forward and downward between the front driven wheel (11) and the drive wheel (15). Various operation levers and an interlocking connection mechanism interposed between the various operation levers and the transmission unit (5) are disposed above the upper rotation unit (16a). A work vehicle having an installation space (S) for installation.