JP3597576B2 - Operating part structure of agricultural tractor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an operation unit structure of an agricultural tractor provided with a crawler-type traveling unit.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a work vehicle having a crawler-type traveling unit that is independent of the left and right, for example, there is a combine, in which the left and right traveling units can be driven to travel by a hydrostatic drive transmission (hereinafter, referred to as “HST”). Two rod-shaped operation levers provided independently on the left and right are interlockedly connected to the trunnion lever of the HST, and the steering operation can be performed by rotating each operation lever in the front-rear direction.
[0003]
[Problems to be solved by the invention]
However, when the left and right HSTs are operated by independent left and right operation levers as in the above-described combine, the shift operation for adjusting the traveling speed of the aircraft and the turning operation for steering the aircraft are performed using the same lever. Therefore, there is a problem that the operability is poor and the driving operation cannot be performed smoothly.
[0004]
[Means for Solving the Problems]
Therefore, in the present invention, a left and right traveling hydraulic motor is provided in each of a pair of left and right crawler traveling units, and a left and right traveling hydraulic pump for driving each traveling hydraulic motor is disposed below the floor of the operating unit. On the same floor, there is provided an operation unit for changing the rotation ratio of the left and right traveling hydraulic motors and for steering and shifting a transmission that increases and decreases the speed by synchronizing the left and right traveling hydraulic motors. In the structure of the operating part of the tractor, a support shaft insertion pipe with a handle supporting shaft inserted in the operating table with the operating part installed is erected, and the center part of the circular handle is attached to the upper end of the handle supporting shaft. On one side of the insertion tube, a shift lever for shifting the left and right running parts and an interlocking mechanism for interlocking the shift lever and the operation unit are arranged, and on the other side of the support shaft insertion tube, Right and left traveling hydraulic motor A brake pedal which is interlocked to the built-in brake system, respectively, by disposing the brake pedal lock mechanism for locking the brake pedal depression operation state, further, the shift lever is a lower vicinity of the handle, the shift lever It is an object of the present invention to provide an operation part structure of an agricultural tractor, wherein a tip grip part is disposed at a position where a distance from a grip part of a handle and a rotation axis is substantially equal.
[0006]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0007]
A shown in FIGS. 1 to 3 is an agricultural tractor provided with an operation unit M according to the present invention. The agricultural tractor A has a three-point link type of various working machines such as a rotary tilling machine B at the rear. Are connected so as to be able to move up and down freely by an elevating mechanism C.
[0008]
As shown in FIGS. 1 to 3, the agricultural tractor A has a vehicle body frame 3 laid horizontally between traveling frames 2, 2 of a pair of right and left crawler traveling parts 1, 1. While the motor unit 4 is provided at the front, the integrally supported machine frame 5 is mounted at the rear via the front and rear anti-vibration devices 6, 6, 7, and 7, and the cabin 8 and the fuel tank 9 and a hydraulic oil tank 10 are provided.
[0009]
As shown in FIGS. 1 and 2, the motor unit 4 attaches a battery 11 to a lower part of the front end of the vehicle body frame 3 via a battery mount 12, and sequentially turns the capacitor 13 from the front end of the vehicle body frame 3 backward. , An oil cooler 14, a radiator 15, an engine 16, a muffler 17, a main cleaner 18, and a pre-cleaner 19, and an air cut plate 20 is set up between the engine 16 and the main cleaner 18 from the body frame 3. The prime mover unit 4 is covered by a bonnet 21 and a front grill 22 which is attached to the front edge of the bonnet 21 via a pivot bracket 23 so as to be openable and closable forward. Reference numeral 24 denotes an elevating mechanism mounting member that stands between the rear ends of the vehicle body frame 3.
[0010]
In addition, the transmission unit 25 is interlocked to the engine 16, and the engine 16 and the transmission unit 25 are integrally supported by the vehicle body frame 3 via a vibration isolator (not shown). Has an anti-vibration effect.
[0011]
As shown in FIGS. 1 to 3, a cabin 8 is mounted on the integrally supported machine frame 5, and an operation unit M is provided on a floor F in the cabin 8. The rotation ratio of the left and right traveling hydraulic motors ML and MR, which will be described later, is changed, and the HST as a continuously variable transmission that speeds up and down by synchronizing the left and right traveling hydraulic motors ML and MR is made steerable and shiftable. At the same time, a seat 26 is disposed at a position immediately behind the operation unit M via a seat support 27 to form a driving unit Q.
[0012]
Next, the operation unit M which forms the gist of the present invention will be described with reference to FIGS.
[0013]
That is, as shown in FIGS. 4 to 7, the operation unit M has a handle column 28 erected on the operation table 40, and a circular handle 29 is attached to the upper end of the handle column 28. While the speed change lever 30 is mounted near the left side, the accelerator lever 81 is mounted near the right side, the PTO on / off lever 82 is mounted immediately below the accelerator lever 81, and the brake pedal 31 is mounted on the right side of the operation console 40. It is arranged. 83 is a brake pedal lock mechanism, 83a is a lock hook, 83b is a lock hook rotation operation lever, 84 is an engine starter switch, and a switch operation plate interlocked with the brake pedal 83 when the engine starter switch 84 is depressed. The switch 85 is brought into contact with and turned on.
[0014]
In the handle column 28, as shown in FIGS. 4 to 7, a support shaft insertion pipe 32 having a lower end communicated with the ceiling wall of the operation console 40 is set up directly upward, and is also raised rearward from the middle part. The handle support shaft 33 is inserted through the support shaft insertion tube 32 to slide the lower end of the handle support shaft 33 to form a part of an HST acceleration / deceleration mechanism N described later. The central portion of the circular handle 29 is attached to the upper end of the handle support shaft 33 while being linked to the body 45.
[0015]
As shown in FIGS. 4 to 7, a support cylinder 34 whose axis is oriented vertically in the condor column 28 is mounted on the upper part of the support shaft insertion pipe 32 via mounting brackets 35, 35. The lever support shaft 36 is inserted through the support shaft 34, and the lower end of the lever support shaft 36 is interlockingly connected to a speed change shaft 41, which is suspended in an operation table 40, which will be described later, via an interlocking mechanism 37. The transmission lever 30 is attached to the upper end of the shaft 36. The transmission lever 30 extends the tip grip 30a outward to the left from the middle part, and grips the tip grip 30a with the circular handle 29. The portion and the handle support shaft 33 are disposed at a position immediately below the left side where the distance from the shaft center is substantially equal.
[0016]
In this manner, the crawler-type left and right traveling sections 1 and 1 can be steered by the circular handle 29, so that the steering operation can be performed smoothly and reliably even in muddy wetlands. Thus, the operability can be improved.
[0017]
In addition, a shift lever 30 for shifting the left and right traveling parts 1 and 1 is disposed near the lower part of the handle 29, and the tip grip 30a of the shift lever 30 is connected to the grip of the handle 29 and the handle support shaft 33. Arranged at a position where the distance from the axis is substantially equal, the operator can easily shift the shift lever 30 with the left hand while holding the handle 29 with the right hand and performing the steering operation. I have. Therefore, safe and reliable steering operation can be performed even in a work requiring frequent forward / reverse switching operation, and operability can be improved from this point as well.
[0018]
As shown in FIGS. 4 and 6, the interlocking mechanism 37 attaches the arm 65 to the lower end of the lever support shaft 36, fixes the rear end to the support shaft insertion tube 32, and projects the front end forward. An intermediate portion of the triangular plate 67 is pivotally supported on the plate 68 by a pivot 69 whose axis is oriented in the left-right width direction, and a connecting rod 66 is interposed between one top of the triangular plate 67 and the arm 65. A connecting rod 70 is provided between the other top of the triangular plate 67 and one end of a cam plate 71 disposed immediately below the triangular plate 67, and the cam plate 71 is substantially a fan. The cam plate 71 is formed in a mold shape and pivotally supported on a support shaft 72 via a fulcrum boss 71b provided at the center thereof. The cam plate 71 extends in the radial direction from the vicinity of the support shaft 72 and gradually becomes tangential. The curved cam groove 71c is opened, and the cam groove 7c is opened. The sliding roller 73 is engaged with the cam groove 71c so as to be slidable along the cam groove 71c. On the other hand, the sliding roller 73 is supported by an arm 74. The arm 74 is fixed to a rotatable horizontal shaft 75, and the arm 74 is arranged so that the direction of rotation of the arm 74 is perpendicular to the direction of rotation of the cam plate 71. That is, the rotation locus of the sliding roller 73 is set to be substantially in the radial direction about the support shaft 72. An arm 79 is fixed on the horizontal shaft 75, one end of a connecting rod 80 is pivotally connected to the arm 79, and the other end of the connecting rod 80 is provided at an end of the transmission shaft 41. It is pivotally connected to an arm 78 projecting from the portion 41a.
[0019]
With this configuration, by rotating the shift lever 30, the lever support shaft 36 is rotated, and the triangular plate 67 is rotated via the arm 65 and the connecting rod 66. The cam plate 71 is rotated via the connecting rod 70, and the rotation of the cam plate 71 causes the sliding roller 73 to slide along the cam groove 71 c, and the arm 74 is rotated, thereby turning the arm 79 and the connecting rod 80. The main transmission shaft 41 is rotated via the arm 78.
[0020]
Here, in the embodiment of the present invention, as shown in FIGS. 4 and 14, the two-pump two-motor type HST is a continuously variable transmission, and the left and right traveling parts 1 and 1 can be driven separately. The handle 29 is of a rotary type so that the aircraft can be turned by changing the number of revolutions and the direction of rotation of each of the crawlers of the left and right traveling units 1 and 1 in accordance with the amount of rotation so that the gear can be turned. The rotation speed and the rotation direction of the left and right traveling hydraulic motors ML, MR can be changed by rotating the 30.
[0021]
The shift lever 30 and the handle 29 are configured to be separately operable, and are linked to a pair of left and right HST acceleration / deceleration mechanisms N, N in the operation console 40. As shown in FIG. 14, the left and right swash plates 98, 99 of the left and right traveling hydraulic pumps PL, PR of the HST are connected to each other, and the left and right traveling hydraulic motors ML, MR are connected to the respective hydraulic pumps PL, PR. The left and right swash plates 101 and 102 of each of the hydraulic motors ML and MR are controlled so that the left and right traveling units 1 and 1 can be moved forward, backward and stop, respectively.
[0022]
That is, as shown in FIGS. 8 and 9, the internal configuration of the operation console 40 is substantially symmetrical, so that one side will be described. In front of the transmission shaft 41 having a triangular cross section, it is parallel to the transmission shaft 41. The slide shaft 44 is suspended horizontally. A pair of left and right slide bodies 43, 43 as steering switching bodies are externally slidably fitted on the transmission shaft 41 so as to be slidable in the axial direction, and a slide action body 45 interlocked with the handle 29 between the slide bodies 43, 43. , And HST acceleration / deceleration mechanisms N, N are interlockingly connected to the respective slide bodies 43, 43. The HST acceleration / deceleration mechanism N includes a guide body 50, a rotor 51, a rotor support arm 52, A swash plate operating arm 55, a first connecting rod 56, a first arm 86, an intermediate shaft 87, a second arm 88, and a second rod 89 are provided.
[0023]
The sliding action body 45 is formed of a base 45b slidably mounted on the slide shaft 44 in the axial direction, and a main body 45c integrally mounted on the base 45b and disposed immediately below the transmission shaft 41. The main body 45c has a substantially L-shape in cross section bent downward from the side of the main transmission shaft 41, and a rack 45a is fixed to the lower surface in the left-right direction.
[0024]
A pinion gear 46 meshes with the rack 45a. The pinion gear 46 is fixed to a pinion shaft 46a, and the pinion shaft 46a is attached to the lower end of the handle support shaft 33 of the handle 29 disposed above. Therefore, when the handle 29 is rotated, the pinion gear 46 is rotated, and the rack 45 a is slid in the left and right direction in conjunction therewith, and the slide action body 45 is slid accordingly, and the slide body 45 is slid via the guide support arm 47. 43, 43 is pushed.
[0025]
The arm support portion 47a of the guide support arm 47 is loosely fitted inside the outer peripheral surface of the slide body 43, and the detent body 47b is extended toward the slide shaft 44 from the front outer peripheral surface portion of the arm support portion 47a. The rotation stopper 47b is loosely fitted to the slide shaft 44 so as to be slidable in the left-right direction. On the other hand, the arm support portion 47a extends rearward and downward from a rear portion thereof, and a boss portion 47c is attached to a tip of the arm support portion 47a. A pivot pin 47d having an axis in the front-rear direction is rotatably mounted on the boss portion 47c. The center of the front wall of the guide body 50 is fixed to the rear end of the pivot pin 47d. The guide body 50 extends in the left-right direction, and is formed in a U-shape in cross section with an open rear surface.
[0026]
Further, the swing arm 48 extends rearward from the outer periphery of the slide body 43, and the upper end of a swing link 48c, which is adjustable in expansion and contraction, is connected to the tip of the swing arm 48 via a connecting pin 48a. The lower end of the swing link 48c pivotally supports one end on one side of the front wall of the guide body 50 via a connecting pin.
[0027]
A rotatable rotator 51 is inserted into the recess of the guide body 50 and is slidably fitted in the left-right direction. The axis of the rotator 51 extends in the left-right direction. An arm support having an axial line in the front-rear direction is attached to one end of the child support arm 52, and the other end of the rotor support arm 52 is fixed to a rear wall of the operation table 40 via a boss 53. An end of a swash plate operating arm 55 extending vertically is fixed to an end of the arm support shaft 54 by a fixing bolt 55a on the outside of the operation table 40. The other end of the first connecting rod 56 is connected to the other end via a connecting pin 56a, and the other end of the first connecting rod 56 has an L-shaped lever 105 pivotally supported at an intermediate portion to the bottom of the operation console 40. Is connected to the other end of the L-shaped lever 105 by a second connection. One end of a rod 106 is connected, the distal end of a first arm 86 is connected to the other end of the second connecting rod 106, and the base end of the first arm 86 is attached to the HST with its axis oriented vertically. The base of the second arm 88 is attached to the upper end of the shaft 87, the base end of the second arm 88 is attached to the lower end of the intermediate shaft 87, and one end of the third connecting rod 89 is connected to the distal end of the second arm 88. The other end of 89 is connected to the swash plate connecting arm 100 of the HST. 107 is an L-shaped lever support shaft.
[0028]
In such a configuration, the rotation of the handle 29 causes the slide action body 45 to slide, and one of the slide bodies 43, 43 is pushed along the slide shaft 44 and the speed change shaft 41 via the guide support arm 47. The guide body 50 provided integrally with the slide body 43 is slid in the directions of arrows a and a shown in FIG.
[0029]
When the transmission shaft 41 is rotated by the transmission lever 30, the guide body 50 swings up and down as shown by arrows b and b around the pivot pin 47d via a swing link 48c connected to the slide body 43. Then, the swash plate operating arm 55 is swung about the arm support shaft 54 as shown by arrows cc.
[0030]
Next, the state of the guide body 50 when the handle 29 and the shift lever 30 are operated will be described with reference to FIGS. That is, when the shift lever 30 is set to the neutral state and the rotary handle 29 is set to the neutral state at the same time, the left and right guide bodies 50, 50, the rotor support arms 52, 52, and the swash plate operating arms 55, 55 As shown in FIG. 10, the horizontal posture is maintained. When the shift lever 30 is shifted to the forward shift position from this state, the shift shaft 41 rotates, and the left and right slide bodies 43, 43, the swing arms 48, 48, and the swing links 48c, 48c are interlocked. Are rotated about the pivot pins 47d, 47d, and the rotor support arms 52, 52, the arm support shafts 54, 54, and the swash plate actuation are performed via left and right rotors 51, 51. As shown in FIG. 11, the arm for use 55, 55 is in an inclined posture. In this case, the left and right swash plates 101 and 102 for controlling the left and right traveling hydraulic motors ML and MR have the same inclination angle, the left and right traveling parts 1 and 1 travel forward at the same speed, and the aircraft goes straight. .
[0031]
Next, when the handle 29 is rotated clockwise from the straight traveling state, the pinion shaft 46a rotates, and the rack 45a meshing with the pinion gear 46 moves rightward, and together with the rack 45a, The slide action body 45 pushes the slide body 43 to the left to slide. Then, the right guide body 50 moves rightward integrally with the slide body 43, and the guide body 50 slides rightward while maintaining the inclined posture. Then, the rotor 51 fitted to the right guide body 50 is pushed down as shown in FIG. 12 and is fitted to a substantially central position of the right guide body 50, The right rotor supporting arm 52 and the swash plate operating arm 55 are rotated to approach a horizontal posture, and the right swash plate 102 for controlling the right traveling hydraulic motor MR is approached to a neutral state. In this case, the right traveling unit 1 decelerates or stops from the straight traveling state, and the left traveling unit 1 keeps moving forward, so that the aircraft slowly turns right.
[0032]
Next, when the steering wheel 29 is further rotated in the right-turning direction in the right-turning state, the right guide body 50 slides further to the right while maintaining the inclined posture, and as shown in FIG. The rotor 51 is engaged with the left portion of the guide body 50, the rotor support arm 52 and the swash plate operating arm 55 assume a left-right-right-low inclined posture, and move the right swash plate 102 to the reverse control side. Incline. In this case, the right traveling unit 1 travels backward while the left traveling unit 1 travels forward, so that the aircraft makes a spin turn.
[0033]
Next, the hydraulic circuit K will be described with reference to FIG. That is, the hydraulic circuit K connects the HST hydraulic circuit 90 to the hydraulic tank T, and connects the left traveling unit driving hydraulic circuit 91 and the right traveling unit driving hydraulic circuit 92 to the HST hydraulic circuit 90, respectively. A work machine elevating hydraulic circuit 93 is connected to the work machine elevating hydraulic pump P1 operatively connected to the left and right running hydraulic pumps PL, PR of the circuit 90, and a charge pump operatively connected to the left and right running hydraulic pumps PL, PR. P2 is connected via a rotary valve 94 to brake devices 95, 96 provided in the left and right traveling unit driving hydraulic circuits 91, 92, respectively. 97 is a bypass operation switching valve.
[0034]
The brake pedal 31 is interlockedly connected to the rotary valve 94, and the rotary valve 94 is switched to operate in conjunction with the depression operation of the brake pedal 31, so that the brake devices 95 and 96 are configured to operate the brakes. I have.
[0035]
That is, the brake devices 95, 96 are provided with piston rods 95c, 96c urged in the extending direction by springs 95b, 96b in cylinders 95a, 96a, respectively, and press-contact members 95d, 96d are provided at the tips of the piston rods 95c, 96c. And pressurizing the springs 95b, 96b by supplying oil into the cylinders 95a, 96a so that the pressure contact bodies 95d, 96d can be freely connected to and separated from the drive wheels 1a, 1a of the traveling parts 1, 1. The piston rods 95c, 96c are shortened against the pressure, so that the pressure contact bodies 95d, 96d are separated from the drive wheels 1a, 1a so that the cylinders 95a, 96a can be brought into a non-brake operating state. By discharging the oil from the inside, the piston rods 95c, 95b are urged by the springs 95b, 96b. 6c a by extending action, pressure member 95d, 96d of the driving wheels 1a, in the pressure contact state 1a so that it is possible to make the brake operation state.
[0036]
In this way, by depressing the brake pedal 31, the driving of the left and right traveling units 1, 1 can be simultaneously stopped by the left and right braking devices 95, 96, so that the same operation as in an automobile can be performed in an emergency. The brake can be depressed with the feeling of pedal operation, and safety can be ensured well.
[0037]
【effect】
According to the present invention, the following effects are produced.
[0038]
That is, according to the first aspect of the present invention, since the crawler-type left and right traveling portions can be steered by the circular handle, the steering operation is performed smoothly and reliably even in muddy wetlands. Operability can be improved.
[0039]
In addition, the shift lever for shifting the left and right running parts is arranged near the lower part of the handle, and the tip grip of the shift lever is located at a position where the distance from the grip of the handle and the rotation axis is substantially equal. Because of the arrangement, the steering operation can be performed by holding the handle with one hand, and the shift lever can be easily shifted with the other hand. Therefore, safe and reliable steering operation can be performed even in a work requiring frequent forward / reverse switching operation, and operability can be improved from this point as well.
[0040]
Furthermore, interlockingly connected to the brake device and the brake pedal which incorporates on the left and right travel hydraulic motor, in order to have arranged the same brake pedal at the bottom of the handle struts, like the pedal operation feeling and car even in an emergency Thus, the brake pedal can be operated to depress the brake pedal, safety can be ensured well, and the operability can be improved in this respect as well.
[Brief description of the drawings]
FIG. 1 is a side view of an agricultural tractor having an operation unit structure according to the present invention.
FIG. 2 is a plan view of the agricultural tractor.
FIG. 3 is a rear view of the agricultural tractor.
FIG. 4 is a left side view of the operation unit.
FIG. 5 is a right side view of the operation unit.
FIG. 6 is a front view of the operation unit.
FIG. 7 is a plan view of the operation unit.
FIG. 8 is a sectional plan view showing the structure inside the operation console.
FIG. 9 is a partial perspective view showing the structure inside the operation console.
FIG. 10 is a partial front view of the operation console in a neutral state.
FIG. 11 is a partial front view of the operation console in a straight traveling state.
FIG. 12 is a partial front view of the operation console in a right turning state.
FIG. 13 is a partial front view of the operation console during a pivot turn.
FIG. 14 is a hydraulic circuit diagram.
[Explanation of symbols]
A Agricultural tractor 1 Running section 2 Running frame 3 Body frame 4 Engine section

Claims (1)

Left and right traveling hydraulic motors (ML, MR) are provided in a pair of left and right crawler traveling parts (1, 1), respectively, and a left and right traveling hydraulic pump (PL, PR) is located below the floor (F) of the driving unit (Q), and the rotation ratio of the left and right traveling hydraulic motors (ML, MR) is changed on the floor (F). In the operation unit structure of an agricultural tractor provided with an operation unit (M) for steering / shifting a transmission that increases and decelerates by synchronizing a traveling hydraulic motor (ML, MR),
A support shaft insertion pipe (32) in which a handle support shaft (33) is inserted is erected on an operation console (40 ) containing the operation unit (M) , and a circular handle ( ) is provided at the upper end of the handle support shaft (33). 29) Attach the center,
A shift lever (30) for shifting the left and right running parts (1, 1) is linked to one side of the support shaft insertion pipe (32) , and the shift lever (30) and the operating part (M) are interlocked. With the interlocking mechanism (37) to be connected ,
On the other side of the support shaft insertion pipe (32) , a brake pedal (83) interlockingly connected to a brake device (95, 96) built in each of the left and right traveling hydraulic motors (ML, MR) , and this brake pedal (83 ) And a brake pedal lock mechanism (83) that locks in the depressing operation state ,
Further, the shift lever (30) is a lower vicinity of the handle (29), the distance is substantially equal to the rotational axis and the gripping portion of the distal clasps of shift lever (30) and (30a) a handle (29) An operation part structure of an agricultural tractor, wherein the operation part is arranged at a position as follows.

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