JP2008207749A - Farm working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that a load of a worker is applied to each non-driven rear wheel and therefore marks for dragging the rear wheels are left in various operations in a farm field, thus resulting in the deterioration of workability and infavorable appearance. <P>SOLUTION: This farm working vehicle comprises right and left front wheels (20F, 20F), right and left rear wheels (20R, 20R), a working machine (3) elevatable between the front and rear wheels, a control seat (29) arranged above the rear wheels (20R, 20R) seen from a side, a riding operation handle (19) steering the vehicle body to the right and left upon riding, and a walking operation handle (18) raising and rotating the vehicle body on the rear wheel (20R, 20R) side with the front wheel (20F, 20F) grounding parts as fulcrums by a pressurizing operation. A hydraulic pump (103) is provided on a way to a transmission path for transmitting power to a front wheel traveling system variable-speed mechanism (M1) from an engine (E), and hydraulic motors (100, 100) rotating by being supplied with pressure oil from the hydraulic pump (103) are connected to the right and left rear wheels (20R, 20R), respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a farm vehicle equipped with left and right front wheels, left and right rear wheels, and a working machine between the front and rear wheels so that the work machine can be raised and lowered. The present invention relates to a farm vehicle including a walking operation handle that lifts and rotates an end portion of a vehicle body opposite to the fulcrum with the front wheel as a fulcrum by a pressing operation.

2. Description of the Related Art Conventionally, there is a farm vehicle equipped with left and right front wheels, left and right rear wheels, and a working machine that can be moved up and down between the front and rear wheels. Further, the farm work vehicle includes a steering operation handle that rides left and right, and a walking operation that lifts and rotates the end of the vehicle body opposite to the fulcrum with the front wheel as a fulcrum by pressing operation. It is set as the structure provided with a handle (patent document 1).
JP 2005-047442 A

  However, since the farm vehicle described above is configured to drive the front wheels but not the rear wheels, the rear wheels are dragged during traveling, and there are traces of rear wheel drag remaining in various operations on the field. And it was not good looking.

  Further, although the rear portion of the vehicle body is lifted with the front wheel as a fulcrum, if the weight of the rear wheel is increased, the above-described upward rotation of the operation handle during walking is hindered, and workability is impaired.

In the present invention, in order to solve the above-described problems, a rotary work machine is configured as follows.
In other words, the left and right front wheels (20F, 20F), the left and right rear wheels (20R, 20R), the work machine (3) that can be moved up and down between the front and rear wheels, and the rear wheels (20R, 20R) as viewed from the side A pilot seat (29) to be taken, a steering operation handle (19) for riding and steering the aircraft from side to side, and a rear wheel (20R, 20R) with the front wheel (20F, 20F) grounding portion as a fulcrum by pressing operation Hydraulic farm (103) in the middle of a transmission path for transmitting power from the engine (E) to the front-wheel drive system transmission mechanism (M1) in a farm vehicle including a walking operation handle (18) for raising and lowering the side body. And the left and right rear wheels (20R, 20R) are connected to hydraulic motors (100, 100) that are rotated by pressure oil supply from the hydraulic pump (103), respectively.

If comprised in this way, it will drive | work by synchronizing the rotation of rear-wheel 20R, 20R with front wheel 20F, 20F by giving the rotation proportional to front-wheel 20F, 20F to hydraulic motor 100,100.
During boarding, direction correction and turning operations are performed by the operation handle 19 when riding, and direction correction and turning operations are performed by the steering handle 18 during walking, especially in front wheels 20F and 20F. Is pushed down, the rear wheels 20R and 20 are lifted, and the front wheels 20F and 20F are kept in the ascending state and turn.

  Since the present invention is configured as described above, the traveling direction of the conventional non-driven rear wheels 20R and 20R is corrected by operating the riding handle 19, but the rear wheels 20R and 20R are in a direction deviating from the traveling direction of the airframe. However, as described above, the rear wheels 20R, 20R were deteriorated by dragging with rolling to cause a dragging phenomenon, resulting in a large traction load and poor running performance and a poor field finish. Is driven by hydraulic motors 100 and 100 to eliminate the drag phenomenon.

  Further, since the cockpit 29 is arranged above the arrangement position of the rear wheels 20R, 20R, most of the passenger's load is applied to the rear wheels 20R, 20R, and these rear wheels 20R, 20R are used as drive wheels. Since it comprises, the said drag | drug phenomenon can be eliminated and workability | operativity can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
First, the overall configuration of the agricultural work vehicle T will be described.
As shown in FIGS. 1 and 2, the farm vehicle T has a front frame 11 made of a square pillar material arranged in parallel along the front-rear direction on the left and right of the front part of the vehicle body, and between the left and right front frames 11, 11. Two auxiliary frames 12 and 12 for mounting the engine are bridged. Further, the rear frame 14 is connected to the rear end portion of the front frame 11 via an intermediate frame 13 arranged in the vertical tilt direction, and the cockpit support plate 15 is bridged between the rear portions of the rear frames 14 and 14. At the same time, the rear end portions of the rear frame 14 are connected to each other by a rear wheel support frame 16, and the front frames 11, 11, the rear frames 14, 14 and the rear wheel support frame 16 constitute a vehicle body frame.

  The front ends of the left and right front frames 11, 11 are connected by a battery mounting plate 17 having an L-shape in side view, and a battery B charged by the engine E is placed on and fixed to an intermediate portion of the plate 17, The left and right side surfaces of the frames 11 and 11 are configured to attach a base portion of a walking handle 18 having a loop shape in a plan view. Thus, the walking handle 18 can be used as a bumper for protecting the front of the vehicle body when the operator is on the vehicle, or as a narrow guide so as to prevent the crops from being damaged by sorting tall crops left and right. .

  Further, front wheels 20F, 20F are pivotally supported below portal cases 42, 42 which transmit engine E rotation, and the steering clutch 45 for the front wheels 20F, 20F is provided on the left and right sides of the walking handle 18. , 45 is provided with clutch levers 22, 22 that individually turn on and off left and right, and a vehicle stop lever 23 that holds both clutches 45, 45 off is provided on one side of the left and right.

  Further, a plurality of rods 21 projecting outward from the front frame 11 are installed between the engine mounting auxiliary frames 12 and 12, and the brackets on the rods 21 are lifted and lowered as working machine lifting and lowering actuators. The base of the electric cylinder 24 is attached.

  A handle post 25 is provided at the rear of the engine E, and a riding handle 19 projects from the upper end of the post 25. The steering wheel 26 is pushed and pulled in conjunction with the rotation of the steering shaft 26. And the clutches 45, 45 of the left and right front wheels 20F, 20F can be individually turned on and off by pushing and pulling the wires.

  As a result, when the riding handle 19 is rotated to the left, the clutch 45 of the left front wheel 20F is disengaged, the vehicle is steered to the left with the left front wheel 20F as a fulcrum, and when the handle 19 is rotated to the right, the right The clutch 45 on the front wheel 20F side is turned off, and the vehicle can be steered to the right with the right front wheel 20F as a fulcrum.

  A step floor 28 is supported above the rear frame 14, the pilot seat 29 is supported so as to be positioned above the rear floor 28, and the rear ends of the frame 14 are connected to the left and right widths of the floor 28. The two rear wheel support frames 16 and 16 projecting outward are connected to each other, and caster type rear wheels 20R and 20R are attached to the left and right outer ends of the support frames 16 and 16, respectively. .

  The left and right rear wheels 20R, 20R are connected to a wire that is pushed and pulled in conjunction with the rotational operation of the steering shaft 26, and are steered to the left and right in conjunction with the rotational operation of the handle 19 during riding. ing.

  In addition, a plate member is bridged between the two rear wheel support frames 16 and 16 as a reinforcing member, and a step 30A for getting on and off when getting on and off from the rear of the vehicle body is constituted. Further, a plate member protrudes forward also on the support arm 31 of the rear wheel 20R extending below the frame 16, and constitutes a step 30B for getting on and off from the side of the vehicle body.

  In the agricultural vehicle T configured as described above, the engine E, the battery B, the transmission case 1 and the like which will be described later are concentrated on the front of the vehicle body to increase the weight, while the rear of the vehicle body, particularly the rear wheel 20R, is connected to the front wheel 20F. Compared with the lighter configuration with a small diameter and no drive mechanism, the ground load on the rear wheel 20R is extremely small when the operator gets off.

  Thus, when the operator pushes the walking handle 18 downward and lifts the rear part of the vehicle body with the front wheel 20F as a fulcrum, the operator can operate with as little force as possible, and the operability during the walking operation can be improved.

  Reference numeral 32 in FIG. 1 denotes an auxiliary pedal protruding forward of the battery B. When the walking handle 18 is pressed, the pedal 32 is depressed to apply weight, and the walking handle 18 is pressed. It is configured to assist pressure. An alternate long and short dash line X indicates a left and right center line of the vehicle body, and the traveling system transmission case 1, the cylinder shaft 94, and the cockpit 29 are arranged on this line in addition to the engine E.

Next, the front wheel traveling system transmission mechanism M1, the work machine system transmission mechanism M2, and the rear wheel traveling system transmission mechanism M3 of the agricultural work vehicle T will be described.
The power transmission mechanism M1 for the front wheel traveling system transmits the rotation of the output shaft 40 of the engine E through the transmission mechanisms in the belt case 41, the traveling system transmission case 1, and the front wheel support portal case 42 in order from the transmission upper side. It is configured to transmit and drive the front wheel 20F.

  More specifically, as shown in FIG. 3, the engine output shaft 40 protrudes toward the outside of the vehicle body on one side of the left and right sides of the engine E, and the rotation of the coaxial 40 is rotated on the driving pulley 43 a in the belt case 41. And it is the structure which transmits to the input shaft (1st axis | shaft 50) of the traveling type transmission case 1 via the drive side pulley 43b and the transmission belt 39 which connects both pulleys 43a and 43b.

  The traveling transmission case 1 is a metal case disposed in the center of the vehicle body and arranged in the front-rear direction. The rotation is input from the input shaft 50 at the upper rear portion of the case, and from the output shaft 55 at the lower front portion of the case. It is configured to rotate output.

  The interior of the traveling system transmission case 1 is configured to support a plurality of gear shafts (six shafts in the illustrated example; hereinafter, the first shaft 50, the second shaft 51,... The sixth shaft 55). Reduction gear sets 56 and 57 are provided between the one shaft 50 and the second shaft 51, and between the second shaft 51 and the third shaft 52, respectively, so that the rotation of the first shaft 50 is reduced. . In addition, one end of the third shaft 52 protrudes as a work machine system output shaft, that is, a PTO shaft, on the other side surface of the case opposite to the one side surface of the case from which the first shaft 50 projects, which will be described later. Various work machines R are driven via the work machine system power transmission mechanism M2.

  The fourth shaft 53 is provided with two traveling transmission gears (a first transmission gear 60 for traveling, a second transmission gear 61 of a two-stage gear type), and protrudes from the side of the handle post 25. Both the gears 60 and 61 are slid on the shaft 53 by the main transmission lever 62.

  Then, the first shifting gear 60 for traveling is moved to the right by the shift lever 62 and meshed with the reverse low-speed gear 63 on the second shaft 51, or the third shaft is moved by moving the gear 60 to the left. Meshing with the forward low-speed gear 65 on 52, or moving the traveling second transmission gear 61 to the right to mesh with the reverse high-speed gear 64 on the second shaft 51, or engaging the gear 61 with the left side. And is engaged with the forward high-speed gear 66 on the third shaft 52 to select the first speed out of the two front and rear speeds.

  Further, between the fourth shaft 53 and the fifth shaft 54, a high speed gear set 67 for transmitting the rotational speed at a high speed and a low speed gear set 68 for transmitting the low speed at a low speed are provided, and the auxiliary transmission clutch 69 on the fifth shaft 54 is provided. The fifth shaft 54 is driven by engaging the clutch pawls of either one of the gear sets 67 and 68 by the forward / backward rotation operation of the auxiliary transmission lever on the side of the cockpit 29.

With the main and auxiliary transmission mechanisms in the traveling system transmission mechanism M1 configured as described above, the farm vehicle T can obtain four forward speeds and four reverse speeds.
Still further, a reduction gear set 70 is provided between the fifth shaft 54 and the sixth shaft 55, and the drive-side sprocket 71 provided on the sixth shaft 55 is rotated at a speed reduced by the main and auxiliary transmission mechanisms. The sprocket support shaft 73 is driven via the chain C.

  The traveling output shaft 73 at the lower part of the traveling system transmission case 1 receives a driven sprocket 72 that meshes with the chain C, and constitutes clutches 45, 45 on the left and right of the shaft that supports the sprocket 72, respectively. The traveling output shaft 74 is provided so as to protrude to the outside of the front frame 11 on the driven shaft side of the clutches 45, 45.

Further, the travel output shaft 74 is configured to drive a front wheel axle shaft 76 at the lower part of the case via a chain C inside the front wheel support portal case 42.
In the agricultural vehicle T configured as described above, the traveling gear shift of the forward four steps and the reverse four steps can be appropriately switched by the rotation operation of the main and sub shift levers, and the clutch lever provided in the walking handle 18 By the gripping operation of 22, 22, the clutch 45 can be turned on and off, and the left and right front wheels 20F can be driven to turn the vehicle body left and right.

  On the other hand, as shown in FIG. 1, the working unit 3 is provided in a suspended state between the front wheels and the rear wheels, and is configured to be interlocked with ascending and descending as will be described later. The transmission mechanism M2 will be described.

  As shown in FIGS. 3 and 4, the power transmission mechanism M2 of the work machine system rotates the third shaft (PTO shaft) 52 projected from the side of the transmission case 1 in order from the power upper side. Transmission is performed via the first rotary case 2A serving as a power transmission case, the left and right second rotary cases 46L and 46R, and the left and right third rotary cases 47L and 47R, and further to the rotary work machines R1 and R2. It is the composition to do.

  The first rotary case 2 equipped with the forward / reverse switching mechanism supports five transmission shafts (work system first shaft 80 to work system fifth shaft 84), and a clutch operation shifter 7 at the top. The shifter operation shaft 6 is supported.

  The first rotary case 2 has a configuration in which the contact surfaces of the cases 1 and 2 are fitted together while the PTO shaft 52 protruding from the mission case 1 is inserted. Further, in the first rotary case 2, a work system first shaft 80 that is an upper input shaft, a work system second shaft 81 that is mounted parallel to the work system first shaft 80, and a lower work system third The shaft 82 is supported.

  The second shaft 81 is provided with a relay gear 95 slidably on the same axis 81, while the third shaft 82 is provided with a forward driven gear 96F that meshes with the relay gear 95, and a fourth shaft 83. Is provided with a reverse driven gear 96R that meshes with the relay gear 95, and the relay gear 95 is slid on the shaft 81, thereby rotating the wide gear 86 on the first shaft 80 to the third shaft 82. Alternatively, it is configured to transmit to the fourth shaft 83.

Further, between the third shaft 82 and the fourth shaft 83, a constantly meshing reduction gear set 97 is provided to transmit the rotation transmitted to the forward driven gear 96F to the fourth shaft 83. It has become.
The relay gear 95 is interlocked and connected via a forward / reverse switching lever 99d, a shifter 99a, and a lever operating shaft 99b, and the gear 95 is slid on the shaft by rotating the lever 99d in the left-right direction. It has become.

  Specifically, as shown in FIG. 6A, when the forward / reverse switching lever 99d is rotated inward of the vehicle body, the relay gear 95 slides inward of the vehicle body and the forward drive gear 96F is engaged. The power is transmitted to the fourth shaft 83 by normal rotation. Further, as shown in FIG. 6B, when the forward / reverse switching lever 99d is rotated toward the outer side of the vehicle body, the relay gear 95 slides toward the outer side of the vehicle body, the reverse driven gear 96R is engaged and the power is It is transmitted to the fourth shaft 83 'in reverse.

  The fourth shaft 83 is provided with a reduction gear 98 that transmits power to the cylindrical fifth shaft 84, and the power transmitted through the reduction gear 98 is inserted into the cylindrical fourth shaft 84. The extension shaft 9 serving as the output shaft is driven.

  The extension shaft 9 is composed of two shafts connected to the tube shaft 94 by pins P, and the left and right outer ends project from the left and right of the front frame 11 as shown in FIG. 33 is configured to be inserted and supported. Further, a plurality of mounting holes 34, 34... Are opened at predetermined intervals on both the left and right ends of the extension shaft 9, and the mounting holes 34 are selected to attach and support second rotary cases 46L, 46R described later. It has become.

Next, the raising / lowering configuration of the working unit 3 will be described.
Each of the left and right second rotary cases 46 supports the distal end portion of the extension shaft 9 through the upper portion and transmits the rotation of the extension shaft 9 to the transmission shaft 130 below the case 46 via the rotation of the chain C. The third rotary case 47 has a configuration in which the transmission shaft 130 is passed through and supported by the upper portion of the case 47 and the rotation of the coaxial 130 is transmitted to the tillage drive shaft 101 at the lower portion of the case via the rotation of the chain C. .

  Further, as shown in FIG. 1, the piston tip of the electric cylinder 24 is connected to the upper part of the second rotary case 46, and a plate-like link arm 35 is connected between the third rotary case 47 and the vehicle body frame 11. It is the structure which connects with. As a result, when the piston of the electric cylinder 24 is expanded and contracted, the second rotary case 46 and the third rotary case 47 are refracted to the center of the transmission shaft 130 while being bent up and down, that is, a middle rotary rotary or a rotary rotary provided at the lower portion of the case 47. The working unit is configured to move up and down integrally.

  In the above-described lift interlock mechanism, as shown in FIGS. 7 and 8, a mast portion 131 is provided at the upper portion of the second rotary case 46, and the connecting pin 132 provided on the mast portion 131 and the electric cylinder 24 are expanded and contracted. The second rotary case 46 is configured such that the rear side rotates about the transmission output shaft 9 by the shortening side operation of the electric cylinder 24 by connecting the end of the portion 24a. Conversely, it rotates downward by the extension operation. A first link 133 having one end rotatably connected to the connection pin 132 is erected, and a second link 134 having one end rotatably connected to the frame is crossed to be rotatable. The ends of the links 133 and 134 are connected by adjusting screw rods 135 that are adjustable in distance. Among the links 133 and 134, a female screw piece 136 screwed with the adjusting screw rod 135 is provided at the tip of the second link so as to be freely rotatable about an axis perpendicular to the axial direction of the rod 135. In addition, an idler piece 137 having a large-diameter support hole through which the adjusting screw rod 135 is passed and supported is provided at the tip of the first link so as to be freely rotatable about an axis that is orthogonal to the axial direction of the rod 135. . Reference numeral 138 denotes a stopper provided by being fixed to the tip of the adjusting screw rod 135. With this configuration, the electric cylinder 24 is shortened, so that the position of the idler piece 137 relative to the rod 135 shifts as the rotary case 46 moves up and rotates, and the operation by the electric cylinder 24 is allowed within the range where it contacts the stopper 138. To be.

  In addition to the above configuration, a position regulating mechanism for arbitrarily setting the ascending position of the work implement is configured between the mast portion 131 and the links 133 and 134. That is, the cylindrical body 141 having a predetermined diameter is mounted in the mounting hole 140 provided in the mast portion 131 in the operating range of the first link 133. When the first link 133 comes into contact with the cylindrical body 141, the shortened side operation of the electric cylinder 24 is restricted, and the ascending position of the working part is restricted. It is convenient that the raised position of the working unit can be regulated by a simple operation such as mounting of the cylinder 141, and any raised position can be regulated by preparing the cylinders 141 having different diameters (see FIG. 8).

Next, the rear wheel traveling system transmission mechanism M3 will be described.
The left and right rear wheels 20R and 20R are provided with hydraulic motors 100 and 100, respectively. In other words, the flange portion 100 a formed on the case side of the hydraulic motor 100 is overlapped and fixed to the outside of the lower extension bracket 31 a of the support arm 31. The drive shaft 101 on the hydraulic motor 100 side is fitted in a deformed insertion hole 102a of the driven shaft 102 formed on the rear wheel 20R so as to be able to transmit (FIG. 10).

  The left and right hydraulic motors 100, 100 are rotated by receiving pressure oil supplied from a single hydraulic pump 103 connected to the outer side of the pulley 43 b side of the input shaft 50 disposed at the rear upper part of the transmission case 1. In this configuration, the left and right hydraulic motors 100 and 100 are independently controlled in flow rate from the hydraulic pump 103 via the on / off switching valve 104 and the left and right flow control valves 105 and 105, respectively. It is configured as possible.

  A hydraulic circuit connecting the hydraulic pump 103, the hydraulic motors 100 and 100, the switching valve 104, and the flow control valves 105 and 105 connects a hydraulic hose 106 for supplying and discharging pressure oil. The hydraulic hose 106a up to and including the left and right rear frames 14 is provided along a portion where the left side of the machine body is provided in the front-rear direction, and a switching valve 104 is interposed in the middle thereof. Further, at the lower position of the cockpit 29, the left and right rear frames 14, 14 are respectively provided with left rear wheel / right rear wheel flow control valves 105, 105, and hydraulic hoses 106b, 106b branched from the hydraulic hose 106a. The hydraulic motors 100, 100 for the left rear wheel and the right rear wheel are connected to the ends of the hydraulic hoses 106b, 106b. 106c is a branch block (FIGS. 1 and 3).

  As shown in the outline of the hydraulic circuit in FIG. 3, the switching valve 104 is switched by a manual lever 107 to cut off the supply of pressure oil to the rear wheels 20R, 20R, that is, the four-wheel drive state and the pressure oil supply. It is the structure which can be switched to a two-wheel drive state. The switching valve 104 is disposed below the handle 19 and is disposed at a position where the operator can easily operate the manual lever 107.

  Next, the flow control valves 105 and 105 are both in the form of proportional control valves, and the control current is controlled by the control unit C. That is, the size is set based on the detection result of the rotation detection sensor 110 of the traveling output shaft 74 or the sprocket 72, and the front wheel 20F rotation and the hydraulic motor 100, 100 rotation are in a proportional relationship. In addition to this configuration, the flow control valves 105, 105 can be changed to a four-stage flow rate in advance, and the main / sub transmission mechanism of the front wheel traveling system transmission mechanism M1 can be changed to forward fourth speed by operating the shift lever 62. However, the hydraulic motors 100 and 100 are rotationally driven as a configuration in which the flow rate by the flow rate control valves 105 and 105 can be changed and set in conjunction with the forward shift position of the speed change lever 62.

  As described above, rotation proportional to the front wheels 20F and 20F can be applied to the hydraulic motors 100 and 100 to synchronize the rotation of the rear wheels 20R and 20R with the front wheels 20F and 20F. Therefore, in the conventional non-driven rear wheels 20R, 20R, the correction of the traveling direction causes the soiling phenomenon to be dragged along with the rolling, for example, by turning to the direction deviating from the traveling direction of the aircraft, and the traction load increases and looks good. Although it was made worse, the drag phenomenon is eliminated by driving the rear wheels 20R, 20R with the hydraulic motors 100, 100 as described above.

  Further, in this embodiment, since the cockpit 29 is arranged above the arrangement position of the rear wheels 20R, 20R, most of the passenger's load is applied to the rear wheels 20R, 20R. Since 20R is configured as a driving wheel, the drag phenomenon can be eliminated and workability can be improved.

  Since the hydraulic motors 100 and 100 have the flange portion 100a formed on the case side of the hydraulic motor 100 overlapped and fixed to the outside of the lower extension bracket 31a of the support arm 31, maintenance work can be easily performed from the outside of the machine body. It can be carried out. By providing the hydraulic motors 100, 100 within the full width of the working unit 3, that is, by providing the plane including the outermost side within the outer peripheral edges at both ends at the front position, protection of the hydraulic motors 100, 100 can be ensured. .

  Further, the hydraulic hose 106a from the hydraulic pump 103 to the switching valve 104 is provided along a portion of the rear frame 14 provided on the left side of the body toward the front and rear, and the switching valve 104 is interposed in the middle. Therefore, the hydraulic piping can be protected by the frames 13 and 14. Further, at the position below the cockpit 29, the left and right rear frames 14, 14 are provided with flow control valves 105, 105 for the left rear wheel and the right rear wheel on the left and right, respectively, and hydraulic hoses 106b, 106b branched from the hydraulic hose 106a. Since the rear wheel bracket 31a is provided with the hydraulic motors 100, 100 alone, the hydraulic pump 103, the control valve 105, etc. are provided at different positions on the machine body, and only the motor load is added. Therefore, the burden load can be reduced even when the rear wheels 20R and 20R are raised by the walking handle, and the operability is not impaired.

  In FIG. 9, the rear wheels 20 </ b> R and 20 </ b> R of this embodiment are configured to be interlocked to change the direction in the left-right direction in accordance with the steering operation of the riding handle 19. That is, a steering plate 116 supported by the airframe is provided around the vertical axis by the steering operation of the handle 19, and the steering plate 116 is connected to one end of the connecting rods 117 and 117 on the left and right sides, and the other end is connected. The rear arms 20R and 20R are configured so that the support arms 31 of the rear wheels 20R and 20R are rotated about the longitudinal axis so that the left and right rear wheels 20R and 20R have the same turning angle.

  FIG. 12 shows an interlocking configuration with the steering clutches 45, 45. In other words, the steering clutches 45, 45 are based on the operation of the clutch levers 22, 22, but a pair of left and right steering clutch pedals 110, 110 that can be operated in the riding state are provided at the same time. Clutch switches 111 and 111 that are turned on by a stepping operation are provided, and the flow control valves 105 and 105 are controlled to have a flow rate of 0 by the ON operation of the clutch switches 111 and 111. That is, by setting the drive current of the flow control valve 105 to 0, a flow rate of 0 can be secured, and when an ON signal of the clutch switch 111 is received, a current value corresponding to the rotation speed detection value of the axle rotation detection sensor is supplied. The current value is zero for non-rotating the hydraulic motor 100. Therefore, the left and right clutch pedals 110 and 110 are operated so that the hydraulic motors 100 and 100 on the same side are not rotated, so that the steerability can be ensured and the turning radius can be reduced, and the direction correcting operation is easy.

  The interlock control with the clutch pedals 110 and 110 is executed when the mode switch 112 is operated to switch to the interlock mode. When the independent mode is set, the current output to the flow control valve is turned off. To.

  Furthermore, when the disengagement operation state of the steering clutches 45, 45 continues for a predetermined time, the supply to the hydraulic motor 100 on the steering clutch 45 side is cut off, so that frequent release of the steering clutch is not followed. , Can prevent the aircraft from meandering.

  FIG. 13 shows an unexpected operation during walking by automatically turning off both the left and right flow rate control valves 105 and 105 and automatically selecting whether the vehicle is driven only by the front wheel drive or by the four wheel drive including the rear wheel drive. Safety can be secured by preventing driving force. That is, a seating detection sensor 115 for detecting whether or not an operator is seated in the cockpit 29 is provided, and when the sensor 115 does not detect the operator, that is, during walking driving work, only the front wheels are driven. If comprised in this way, the direction operativity by a walking handle can be improved only by driving the front wheels 20F and 20F during a walking operation. Here, the presence / absence of the operator is detected by the detection sensor 115 provided in the cockpit 29, or when the aircraft tilts more than a predetermined value, it can be regarded as a walking maneuvering state. It can be replaced with driving.

  A configuration in which the hydraulic motor 100 of a farm vehicle is used as a general-purpose drive source will be described with reference to FIG. In FIG. 14, instead of the rotary tiller 3 as a working machine, a mowing device 121 is connected to the front frame 11 and the rear frame 14 via a parallel link mechanism 120 so as to be movable up and down. A transmission case 123 for mounting the lower end side of the parallel link mechanism 120 is provided on the top surface of the deck 122 of the mowing device 121. The hydraulic motor 100 can be attached to and detached from the rear surface of the transmission case 123 by using the flange 100a. It is composed.

  The transmission case 123 is provided with an input shaft 124 that is connected to the shaft of the hydraulic motor 100 so as to be capable of transmission, and a bevel gear mechanism is provided between the input shaft 124 and the support shaft 126 of the rotary blade 125 disposed in the deck 122. It is set as the structure which provides and transmits. Therefore, as the hydraulic motor 100 rotates, the rotary blade 125 can be driven to cut the turf grass and the like on the ground as the aircraft advances.

  The hydraulic motor 100 is configured to be replaced for driving the mowing device 121 from the state for driving the rear wheel 20R, but the hydraulic hoses 106a and 106b along the rear frame 14 are made of a flexible material. Since it can be easily routed by simply attaching and detaching the hydraulic motor 100 main body, can be adapted to a mid-mount work machine, and can easily follow even a structure in which this work machine moves up and down, each drive source is required. Convenient.

  In FIG. 14, an auxiliary frame 127 is provided at the rear end of the rear frame 14, and a chemical solution tank 128 for performing a spraying operation by an unillustrated control nozzle is mounted on the auxiliary frame 127. A chemical liquid pump 129 is attached to one side surface of the chemical liquid tank 128, the chemical liquid is sucked up by driving the pump, and the chemical liquid is supplied from the piping portion 129A to the nozzle. The chemical pump 129 is mounted with the hydraulic motor 100 by a flange portion 100a and used as a driving source for the chemical pump 129.

  Since the chemical pump 129 can be disposed in the rear part of the cockpit 29 and within the reach of the hydraulic hose 106b from the position of the hydraulic motor 100 in the driving state of the rear wheel 20R, it is the same as in the case of the mowing apparatus 121. In addition, by changing the hydraulic motor 100, it can be easily changed to drive the chemical pump 129.

  As described above, by configuring one or both of the hydraulic motors 100 and 100 so as to be detachable, the hydraulic motor 100 can be used as a drive source for other mounting work machines, and the versatility of the hydraulic motor 100 is enhanced.

The whole side view of an agricultural work vehicle. The top view which shows the flame | frame structure of an agricultural work vehicle. The power transmission mechanism diagram of a farm vehicle. Sectional drawing of the 1st rotary case provided with the forward / reverse rotation mechanism. The side view of the 1st rotary case which equipped with the forward / reverse rotation mechanism. (A) (B) Side view which shows switching operation of the forward / reverse switching lever. The side view of a raising / lowering interlocking mechanism part. The side view of a raising / lowering interlocking mechanism part. The expanded back sectional view of a rear-wheel support part. The expansion perspective view of a rear-wheel support part. Block Diagram. flowchart. flowchart. The whole side view of the agricultural work vehicle equipped with another work machine.

Explanation of symbols

3 Working machine 19 Handle 20F at the time of boarding Front wheel 20R Rear wheel 29 Pilot seat 100 Hydraulic motor 103 Hydraulic pump C Control unit M1 Front wheel traveling system transmission mechanism M3 Rear wheel traveling system transmission mechanism

Claims (1)

  The left and right front wheels (20F, 20F), the left and right rear wheels (20R, 20R), the working machine (3) that is movable up and down between the front and rear wheels, and the rear wheels (20R, 20R) in a side view are disposed above. On the rear wheel (20R, 20R) side, with the pilot seat (29), the on-board operation handle (19) that rides and steers the aircraft left and right, and the grounding part of the front wheels (20F, 20F) by pressing operation In a farm vehicle equipped with a walking operation handle (18) for raising and rotating the machine body, a hydraulic pump (103) is provided in the middle of a transmission path for transmitting power from the engine (E) to the front wheel system transmission mechanism (M1). A farm work vehicle characterized in that hydraulic motors (100, 100) rotating by pressure oil supply from the hydraulic pump (103) are connected to the left and right rear wheels (20R, 20R), respectively.

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