JP2007030623A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operationality of a forward/backward traveling changeover switch 130 so that the hand of an operator sitting on a steering seat 8 easily reaches the forward/backward traveling changeover switch 130, in a working vehicle equipped with a speed change transmission mechanism which speed-changes output from an engine 5 mounted on a traveling machine body 2 and transmitting it to traveling parts 3, 3, 4, 4 or a working part. <P>SOLUTION: Armrests 140a, 140b for placing the arm or the elbow of the sitter are provided at the both right and left sides of the steering seat in the traveling machine body 2. The forward/backward traveling changeover switch 130 for operating switching the advancing direction of the traveling machine body 2 between the forward and backward traveling is provided at the portion of the front end side in the right armrest 140a so as to be operated by a hand when the operator's arm is placed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a work vehicle such as a tractor for agricultural work or a wheel loader for civil engineering work.

  Conventionally, in a work vehicle such as a tractor or a wheel loader, a steering handle for steering the traveling vehicle body has been provided at the upper part of the steering column in front of the steering seat, and the traveling direction of the traveling vehicle body on the left and right sides of the steering column A configuration in which a forward / reverse switching lever for switching between forward and reverse is provided is known (see, for example, Patent Document 1).

In this case, the operator can move the traveling machine forward or backward by operating the forward / reverse switching lever as necessary.
JP 2004-90885 A

  By the way, the operator usually sits on the control seat with the body facing in the traveling direction of the traveling aircraft, and operates the tractor with the control handle held with both hands. When the traveling direction of the traveling machine body is switched to forward or reverse, while holding the steering handle with one hand, the steering handle is moved from the steering handle to the forward / reverse switching lever and the forward / backward switching lever is operated.

  However, in the above-described conventional configuration, the forward / reverse switching lever is disposed below the steering handle, so that when the operator switches from the steering handle to the forward / backward switching lever, the operator is slightly bent forward and away from the steering handle. The arm must be extended diagonally forward and downward, and the lever for reversing the forward / reverse direction must be held again, leaving room for improvement in terms of operability.

  Further, a throttle lever for adjusting the engine speed may be provided on the other side of the steering column opposite to the forward / reverse switching lever (see FIG. 2 of Patent Document 1). In Patent Document 1, the forward / reverse switching lever is disposed on the left side of the steering column, and the throttle lever is disposed on the right side of the steering column.

  In such a configuration, for example, when the vehicle speed is changed after the traveling direction of the traveling vehicle is switched to forward or backward, the forward / reverse switching lever is operated with the left hand, the left hand is released from the forward / reverse switching lever, and the control handle is moved from the right hand to the left hand. It was forced to carry out an extremely troublesome operation of holding the throttle lever with a free right hand.

  Therefore, the present invention solves the above-described problems and makes it easy for the operator's hand seated on the control seat to reach the forward / reverse operation means such as the forward / reverse switching lever. It is a technical problem to provide an improved work vehicle.

  In order to achieve this technical problem, the invention of claim 1 is a work vehicle provided with a speed change transmission mechanism that changes the output from an engine mounted on a traveling machine body and transmits the output to a traveling part or a working part. An armrest for placing a seated person's arm or elbow is provided on at least one of the left and right sides of the control seat in the traveling aircraft body, and the armrest is operated to switch the traveling direction of the traveling aircraft body between forward and reverse. Therefore, a forward / reverse operation means is provided.

  According to a second aspect of the present invention, in the work vehicle according to the first aspect, the forward / backward operation means is provided in a portion of the armrest that can be operated with a finger when the arm of the seated person is placed. It is that.

  According to a third aspect of the present invention, in the work vehicle according to the first or second aspect, a steering column having steering means for steering the traveling body is arranged in front of the steering seat, Either one is provided with a main speed change operation means for adjusting the engine speed, and the armrest located on the same side of the control seat as the main speed change operation means is provided with the forward / reverse operation means. It is that.

  According to a fourth aspect of the present invention, in the work vehicle according to any one of the first to third aspects, a speed change operation is performed for switching the speed ratio range of the output speed of the speed change transmission mechanism to the engine speed in multiple stages. At least one of the ratio setting device and the auxiliary transmission operation means for switching the output range of the transmission transmission mechanism between a low speed and a high speed is provided on the armrest.

  According to the first aspect of the present invention, the armrest for placing the arm or elbow of the seated person is provided on at least one of the left and right sides of the control seat in the traveling body, and the traveling direction of the traveling body is forward and backward in the armrest. For example, when switching the traveling direction of the traveling aircraft to forward or backward, the seated person moves the hand on the armrest side with the forward / reverse switching switch to the forward / reverse direction. If it is placed on the armrest, the forward / reverse operation means can be easily operated with the hand on the armrest side, while the other hand holds the steering means. Therefore, the operability of the forward / reverse operation means having a high operation frequency is excellent, and there is an effect that the fatigue of the operator due to a long-time work can be reduced.

  According to the invention of claim 2, since the forward / reverse operation means is provided in a part of the armrest that can be operated with fingers when the arm of the seated person is placed, the forward / reverse operation means is provided. By simply placing the hand on the armrest side on the armrest, the hand on the armrest side can easily reach the forward / reverse operation means. Therefore, the operability of the forward / reverse operation means is further improved.

  According to a third aspect of the present invention, main shift operation means for adjusting the engine speed is provided on either the left or right of the control column in front of the control seat, and the main shift operation means in the control seat is Since the armrest located on the same side is provided with the forward / reverse operation means, for example, when the vehicle speed is changed after the traveling direction of the traveling machine body is switched to forward or backward, the armrest with the forward / backward changeover switch is provided. The hand on the opposite side can hold the steering means and operate the main transmission operation means or the forward / reverse operation means with only the hand on the armrest side. As a result, there is an effect that it contributes to improving the operability of the main shift operation means and the forward / reverse operation means that are frequently operated.

  According to the invention of claim 4, the speed ratio setting device for switching the speed ratio range of the output speed of the speed change transmission mechanism relative to the engine speed in multiple stages, and the output range of the speed change transmission mechanism are set to low speed and high speed. By providing at least one of the sub-shift operation means for switching to the armrest, the group of operation means having a high operation frequency can be collected at the position of the armrest. Therefore, there is an effect that the usability (operability) of each operation means is further improved.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings (FIGS. 1 to 7). FIG. 1 is a side view of a farm tractor, FIG. 2 is a perspective view of the tractor as viewed obliquely from the rear, FIG. 3 is a skeleton diagram of a power transmission system, FIG. 4 is a hydraulic circuit diagram of a hydraulic continuously variable transmission, and FIG. 6 is a plan view of the cabin, and FIG. 7 is a functional block diagram of the control means.

  As shown in FIGS. 1 and 2, a tractor 1 as a work vehicle supports a traveling machine body 2 with a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 and is mounted on a front portion of the traveling machine body 2. By driving the rear wheel 4 and the front wheel 3 with the engine 5, the vehicle 5 is configured to travel forward and backward. The front and rear four wheels 3, 3, 4, and 4 correspond to the traveling portions described in the claims. In this case, a pair of left and right traveling units is constituted by a set of front and rear wheels 3 and 4 positioned on the left side in the traveling direction of the traveling machine body 2 and a group of front and rear wheels 3 and 4 positioned on the right side in the traveling direction.

  The engine 5 is covered with a bonnet 6. A cabin 7 is installed on the upper surface of the traveling machine body 2, and a steering seat 8 on which an operator is seated and a steering column 234 positioned in front of the steering seat 8 are mounted in the cabin 7. Yes. A steering handle 9 (round handle) as steering means is provided on the top of the steering column 234. When the operator seated on the control seat 8 rotates the control handle 9, the steering angles (steering angles) of the left and right front wheels 3 and 3 change according to the operation amount (rotation amount). ing.

  A step 10 for an operator to get on and off is provided on the outer side of the cabin 7, and a fuel tank 11 for supplying fuel to the engine 5 is provided on the inner side of the step 10 and below the bottom of the cabin 7. ing.

  The traveling machine body 2 includes an engine frame 14 having a front bumper 12 and a front axle case 13, and left and right machine body frames 16 that are detachably fixed to the rear portion of the engine frame 14 with bolts 15. A mission case 17 is connected to the rear portion of the body frame 16 for transmitting the rotation of the engine 5 to the rear wheels 4 and the front wheels 3 with appropriate speed change. In this case, the rear wheel 4 is rearwardly attached to the transmission case 17 so as to protrude outward from the outer surface of the transmission case 17 and to the outer end of the rear axle case 18. It is attached via a gear case 19 that is mounted so as to extend.

  A hydraulic working unit lifting mechanism 20 for lifting and lowering a working unit (not shown) such as a tillage machine is detachably attached to the upper surface of the rear portion of the mission case 17. A working unit such as a field cultivator is connected to the rear part of the mission case 17 via a lower link 21 and a top link 22. Further, a PTO shaft 23 for the working portion is provided on the rear side surface of the mission case 17 so as to protrude rearward.

  FIG. 5 shows a hydraulic circuit 200 of the tractor 1 in this embodiment. The hydraulic circuit 200 of the tractor 1 includes a working unit hydraulic pump 94 and a traveling hydraulic pump 95 that are operated by the rotational force of the engine 5.

  The traveling hydraulic pump 95 is connected to a power steering hydraulic cylinder 93 by the steering handle 9 via a power steering control valve 202, while switching valves for operating a pair of left and right auto brake 65 brake cylinders 68, respectively. Are connected to the left and right autobrake solenoid valves 67a and 67b.

  Further, the traveling hydraulic pump 95 is provided for the PTO clutch hydraulic solenoid valve (proportional control valve) 104 for the PTO clutch 100 and the transmission parts of the transmission case 17, that is, the hydraulic continuously variable transmission 29 for main transmission described later. Proportional control valve 203, switching valve 204 actuated thereby, high speed clutch electromagnetic valve 666 of hydraulic cylinder 55 for traveling sub-transmission, and forward clutch for actuating hydraulic clutches 40, 42 for switching forward and backward of traveling machine body 2 To switch the clutch electromagnetic valve 46 and the reverse clutch electromagnetic valve 48, the four-wheel drive hydraulic solenoid valve 80 for the four-wheel drive hydraulic clutch 74 for simultaneously driving the front wheel 3 and the rear wheel 4, and the front wheel 3 to double speed drive. The double speed hydraulic solenoid valve 82 is connected to the double speed hydraulic clutch 76.

  The working unit hydraulic pump 94 is connected to a control electromagnetic valve 201 for supplying hydraulic oil to a single-acting hydraulic cylinder 205 in the working unit lifting mechanism 20. The hydraulic circuit 200 includes a relief valve, a flow rate adjustment valve, a check valve, an oil cooler, an oil filter, and the like.

  FIG. 3 shows the mission case 17. The inside of the mission case 17 is divided forward and backward by a partition wall 31. A front side wall member 32 and a rear side wall member 33 are detachably fixed to the front side and the rear side of the mission case 17 with bolts, respectively. The mission case 17 is formed in a box shape, and a front chamber 34 and a rear chamber 35 are formed inside the mission case 17. The front chamber 34 and the rear chamber 35 are in communication with each other so that the hydraulic oil (lubricating oil) inside these chambers moves relative to each other.

  As shown in FIG. 3, the front side wall member 32 is provided with a front wheel drive case 69 described later. In the front chamber 34, a travel auxiliary transmission gear mechanism 30 and a PTO transmission gear mechanism 96, which will be described later, are arranged. In the rear chamber 35, a hydraulic continuously variable transmission 29, which is a traveling main transmission mechanism described later, and a differential gear mechanism 58 are arranged. The hydraulic continuously variable transmission 29 and the traveling auxiliary transmission gear mechanism 30 correspond to the transmission mechanism described in the claims.

  An engine output shaft 24 is provided on the rear side surface of the engine 5 so as to protrude rearward. A flywheel 25 is attached to the engine output shaft 24 so as to be directly connected. A main drive shaft 26 that protrudes rearward from the flywheel 25 and a main transmission input shaft 27 that protrudes forward from the front surface of the transmission case 17 via an extendable power transmission shaft 28 having universal joints at both ends. Are connected. The rotational power of the engine 5 is transmitted to the main transmission input shaft 27 in the transmission case 17, and then the speed is appropriately changed by the hydraulic continuously variable transmission 29 and the traveling auxiliary transmission gear mechanism 30. The driving force is transmitted to the rear wheel 4 through the rear wheel 4. Further, the rotation of the engine 5 that has been appropriately shifted by the traveling auxiliary transmission gear mechanism 30 is transmitted to the front wheels 3 via the front wheel drive case 69 and the differential gear mechanism 86 of the front axle case 13. Yes.

  The in-line hydraulic continuously variable transmission 29 provided in the rear chamber 35 is configured such that a main transmission output shaft 36 is concentrically disposed on a main transmission input shaft 27, and a variable displacement type transmission hydraulic pump. Part 500 and a constant displacement type shifting hydraulic motor part 501 that operates with high-pressure hydraulic oil discharged from the hydraulic pump part 500. The rear end side of the main transmission input shaft 27 opposite to the input side (front end side) of the main transmission input shaft 27 is rotatably supported on the rear side wall member 33 by a ball bearing.

  A cylindrical main transmission output shaft 36 is fitted on the front side of the hydraulic continuously variable transmission 29, that is, on the input side of the main transmission input shaft 27. A main transmission output gear 37 for taking out the main transmission output from the hydraulic continuously variable transmission 29 is provided on the main transmission output shaft 36. The middle of the main transmission output shaft 36 passes through the partition wall 31, and the front end and the rear end protrude into the front chamber 34 and the rear chamber 35, respectively. The middle of the main transmission output shaft 36 is rotatably supported on the partition wall 31 by two sets of ball bearings. A main transmission output gear 37 is provided at the front end portion of the main transmission output shaft 36. The input side (front end side) of the main transmission input shaft 27 is rotatably supported in the shaft hole of the main transmission output shaft 36 via a roller bearing so as to protrude forward from the front end of the main transmission output shaft 36.

  A cylinder block 505 for the hydraulic pump unit 500 and the hydraulic motor unit 501 is fitted on the main transmission input shaft 27 substantially in the middle between the partition wall 31 and the rear side wall member 33. The hydraulic pump unit 500 is disposed at a position opposite to the input side of the main transmission input shaft 27 across the cylinder block 505, while the hydraulic motor section 501 is disposed at the input side of the main transmission input shaft 27. The

  The hydraulic pump unit 500 has a first holder (not shown) that is fixed to the inner surface of the transmission case 17 so as to face the side surface of the cylinder block 505, and an inclination angle with respect to the axis of the main transmission input shaft 27. A pump swash plate 509 disposed in the first holder in a changeable manner, a shoe (not shown) slidably provided on the pump swash plate 509, a pump plunger 506 coupled to the shoe via a spherical universal joint, A first plunger hole 507 for disposing the pump plunger 506 in and out of the cylinder block 505 is provided. One end of the pump plunger 506 protrudes from the side surface of the cylinder block 505 in the direction of the pump swash plate 509 (8 right side in FIG. 4).

  The cylinder block 505 is provided with the same number of first spool valves 536 as the pump plungers 506. Further, a first radial bearing 537 is disposed in the first holder so as to be inclined at a constant inclination angle with respect to the axis of the main transmission input shaft 27.

  On the other hand, the hydraulic motor unit 501 includes a second holder (not shown) disposed facing the side surface of the cylinder block 505 and a first tilt angle with respect to the axis of the main transmission input shaft 27 so as to maintain a constant inclination angle. A motor swash plate 518 fixed to the two holders, a shoe (not shown) slidably provided on the motor swash plate 518, a motor plunger 515 connected to the shoe via a spherical universal joint, and the motor plunger 515 as a cylinder A second plunger hole 516 is provided in the block 505 so as to freely enter and exit. One end of the motor plunger 515 protrudes from the side surface of the cylinder block 505 in the direction of the motor swash plate 518 (left side in FIG. 4).

  The cylinder block 505 is provided with the same number of second spool valves 540 as the motor plungers 515. Further, a second radial bearing 541 is disposed in the second holder 519 so as to be inclined at a constant inclination angle with respect to the axis of the main transmission input shaft 27. The pump plungers 506 and the same number of motor plungers 515 as the pump plungers 506 are alternately arranged on the same circumference of the rotation center of the cylinder block 505.

  Further, a ring groove-shaped first oil chamber 530 and a ring groove-shaped second oil chamber 531 are formed in the shaft hole of the cylinder block 505 into which the main transmission input shaft 27 is inserted. The cylinder block 505 is formed with a first valve hole 532 and a second valve hole 533 that are arranged at substantially equal intervals on the same circumference of the rotation center. The first valve hole 532 and the second valve hole 533 communicate with the first oil chamber 530 and the second oil chamber 531, respectively. The first plunger hole 507 communicates with the first valve hole 532 via the first oil passage 534, and the second plunger hole 516 communicates with the second valve hole 533 via the second oil chamber 531.

  The first spool valves 536 inserted into the first valve holes 532 are arranged at substantially equal intervals on the same circumference of the rotation center of the cylinder block 505. The tip of the first spool valve 536 protrudes from the first valve hole 532 toward the first holder by the elastic pressure of the back pressure spring force, and the tip of the first spool valve 536 is brought into contact with the side surface of the outer ring of the first radial bearing 537. The Then, the first spool valve 536 reciprocates once in one rotation of the cylinder block 505, and the first plunger hole 507 is connected to the first oil chamber 530 or the second oil via the first valve hole 532 and the first oil passage 534. The chamber 531 is configured to communicate with each other alternately.

  Further, the second spool valves 540 inserted into the second valve holes 533 are arranged at substantially equal intervals on the same circumference of the rotation center of the cylinder block 505. The tip of the second spool valve 540 protrudes from the second valve hole 533 in the direction of the second holder due to the back pressure spring force, and the tip of the second spool valve 540 is brought into contact with the outer ring side surface of the second radial bearing 541. The Then, the second spool valve 540 reciprocates once by one rotation of the cylinder block 505, and the second plunger hole 516 passes through the second valve hole 533 and the second oil passage 535, and passes through the first oil chamber 530 or the second oil. The chamber 531 is configured to communicate with each other alternately.

  Further, a hydraulic oil supply oil passage 543 is formed in the central portion of the main transmission input shaft 27 in the axial direction. The supply oil passage 543 is opened at the rear end face of the main transmission input shaft 27 and communicates with the discharge port of the traveling hydraulic pump 95 described above. Further, the first charge valve 544 for supplying hydraulic oil in the hydraulic oil supply oil passage 543 to the first oil chamber 530 and the second charge valve 545 for supplying hydraulic oil in the hydraulic oil supply oil passage 543 to the second oil chamber 531. And are provided.

  And with respect to the hydraulic closed circuit formed between the first and second plunger holes 507 and 516 and the first and second oil chambers 530 and 531, the first and second charge valves 544 and 545 are passed through, The hydraulic oil is supplied from the hydraulic oil supply oil passage 543. It should be noted that hydraulic oil is supplied from the hydraulic oil supply oil passage 543 to the rotating portions of the hydraulic pump unit 500 and the motor unit 501 as lubricating oil via check valves.

  Further, the pump swash plate 509 is disposed on the outer periphery of the small diameter portion of the first holder via the inclination angle adjustment fulcrum 555. The pump swash plate 509 is configured such that its inclination angle is adjustable with respect to the axis of the main transmission input shaft 27. A main transmission hydraulic cylinder 556 for main transmission, which is an actuator for changing the inclination angle of the pump swash plate 509 with respect to the axis of the main transmission input shaft 27, is provided (see FIGS. 4 and 5). The main transmission hydraulic cylinder 556 is configured to change the inclination angle of the pump swash plate 509 so that the main transmission operation of the continuously variable transmission 29 is performed.

  The main transmission operation of the inline hydraulic continuously variable transmission 29 will be described below. The changeover valve 204 is operated by hydraulic fluid from a proportional control solenoid valve 203 that operates in proportion to the amount of depression of a forward pedal 232 or a reverse pedal 233 (details will be described later) as a gear ratio operation means, and the main transmission hydraulic cylinder 556 is operated. (See FIG. 5) is controlled, and the inclination angle of the pump swash plate 509 provided in the hydraulic pump unit 500 is changed with respect to the axis of the main transmission input shaft 27.

  When the tilt angle of the pump swash plate 509 is substantially zero, the hydraulic motor unit 501 is not driven by the hydraulic pump unit 500, so the cylinder block 505 fitted to the main transmission input shaft 27 and the hydraulic motor unit 501 are provided. The motor swash plate 518 rotated in the same direction at substantially the same rotational speed, the main transmission output shaft 36 is rotated at substantially the same rotational speed as the main transmission input shaft 27, and the rotational speed of the main transmission input shaft 27 is changed. Without being transmitted to the main transmission output gear 37.

  When the pump swash plate 509 is inclined in one direction (positive inclination angle) with respect to the axis line of the main transmission input shaft 27, the motor swash plate 518 is rotated in the same direction as the cylinder block 505, and the hydraulic motor unit 501 is The main speed change output shaft 36 is rotated at a higher rotational speed than the main speed change input shaft 27 and the rotational speed of the main speed change input shaft 27 is increased and transmitted to the main speed change output gear 37. That is, the rotational speed of the hydraulic motor unit 501 is added to the rotational speed of the main transmission input shaft 27 and transmitted to the main transmission output gear 37. Therefore, the shift output (travel speed) from the main shift output gear 37 is proportional to the inclination (positive inclination angle) of the pump swash plate 509 within the range of the rotation speed higher than the rotation speed of the main transmission input shaft 27. As a result, the maximum traveling speed is reached at the maximum inclination (positive inclination angle) of the pump swash plate 509.

  Further, when the pump swash plate 509 is inclined in the other direction (negative inclination angle) with respect to the axis line of the main transmission input shaft 27, the motor swash plate 518 is rotated in the direction opposite to the cylinder block 505, and the hydraulic motor The part 501 is decelerated (reversely rotated), the main transmission output shaft 36 is rotated at a lower rotational speed than the main transmission input shaft 27, and the rotational speed of the main transmission input shaft 27 is decelerated and transmitted to the main transmission output gear 37.

  That is, the rotational speed of the hydraulic motor unit 501 is subtracted from the rotational speed of the main transmission input shaft 27 and transmitted to the main transmission output gear 37. For this reason, the shift output (traveling speed) from the main shift output gear 37 is proportional to the inclination (negative inclination angle) of the pump swash plate 509 in the range of the rotation speed lower than the rotation speed of the main transmission input shaft 27. Is changed to the minimum traveling speed at the maximum inclination (negative inclination angle) of the pump swash plate 509. In the embodiment, when the negative inclination angle of the pump swash plate 509 is approximately 11 degrees, the gear ratio is zero. Although slightly different depending on the gear ratio pattern described later, the gear ratio is set to be maximum when the positive inclination angle is approximately 11 degrees.

  As shown in FIG. 3, in the front chamber 34 of the transmission case 17, the forward gear 41 and the reverse gear 43 for switching between the forward and backward movements of the traveling machine body 2 and the switching between the low speed and the high speed are performed. The traveling auxiliary transmission gear mechanism 30 is arranged.

  A configuration for switching between forward and reverse via the forward gear 41 and the reverse gear 43 will be described. As shown in FIG. 3, a travel counter shaft 38 and a reverse rotation shaft 39 are disposed in the front chamber 34 where the main transmission output gear 37 is disposed. The travel counter shaft 38 is fitted with a forward gear 41 connected by a forward wet multi-plate hydraulic clutch 40 and a reverse gear 43 connected by a reverse wet multi-plate hydraulic clutch 42. Is done. The forward gear 41 is meshed with the main transmission output gear 37. The main transmission output gear 37 is also meshed with a reverse gear 44 provided on the reverse shaft 39. The reverse gear 43 meshes with a reverse output gear 45 provided on the reverse shaft 39.

  Then, when the forward pedal 232 described later is depressed, the clutch cylinder 47 is operated by the forward clutch solenoid valve 46, the forward hydraulic clutch 40 is continued, and the main transmission output gear 37 and the travel counter shaft 38 are connected to the forward gear. It connects so that it may be connected by 41 (refer FIG. 3).

  Further, when the reverse pedal 233 described later is depressed, the clutch cylinder 49 is operated by the reverse clutch solenoid valve 48 and the reverse hydraulic clutch 42 is continued, so that the main transmission output gear 37 and the travel counter shaft 38 are reversely rotated. The reversing gear 44 and the reversing output gear 45 provided on the shaft 39 are connected to the reverse gear 43 (see FIG. 3).

  In the neutral position in which neither the forward pedal 232 nor the reverse pedal 233 is depressed, both the forward and reverse wet multi-plate hydraulic clutches 40 and 42 are both disconnected, and the front wheel 3 and the rear wheel. 4 is configured such that the traveling driving force from the main transmission output gear 37 output to 4 is substantially zero (main clutch disengaged state).

  Next, a configuration for switching between low speed and high speed via the traveling auxiliary transmission gear mechanism 30 will be described. As shown in FIG. 3, a traveling auxiliary transmission gear mechanism 30 and an auxiliary transmission shaft 50 are arranged in the front chamber 34 of the transmission case 17. The travel counter shaft 38 is provided with a low-speed gear 51 and a high-speed gear 53 for sub-transmission, while the sub-transmission shaft 50 has a low-speed gear 52 that meshes with the low-speed gear 51 of the travel counter shaft 38 and a travel counter. A high speed gear 54 that meshes with the high speed gear 53 of the shaft 38 is provided. Further, the auxiliary transmission shaft 50 is provided with a low speed clutch 56 and a high speed clutch 57 that can be connected and disconnected by an auxiliary transmission hydraulic cylinder 55.

  The low speed clutch 56 or the high speed clutch 57 is continued in the auxiliary transmission hydraulic cylinder 55 by operating an auxiliary transmission changeover switch 222 (details will be described later) as the auxiliary transmission operation means or detecting the rotational speed of the engine 5. A low-speed gear 52 or a high-speed gear 54 is connected to the transmission shaft 50, and a traveling driving force is output from the auxiliary transmission shaft 50 to the front wheels 3 and the rear wheels 4.

  The rear end portion of the auxiliary transmission shaft 50 extends through the partition wall 31 to the inside of the rear chamber 35 of the transmission case 17 (see FIG. 3). A pinion 59 is provided at the rear end portion of the auxiliary transmission shaft 50. In addition, a differential gear mechanism 58 that transmits traveling driving force to the left and right rear wheels 4 is disposed in the rear chamber 35. The differential gear mechanism 58 includes a ring gear 60 that meshes with a pinion 59 at the rear end of the auxiliary transmission shaft 50, a differential gear case 61 provided in the ring gear 60, and a differential output shaft 62 that extends in the left-right direction. . The differential output shaft 62 is connected to the rear axle 64 by a final gear 63 or the like, and is configured to drive the rear wheel 4 provided on the rear axle 64 (see FIG. 5).

  A brake 65 is installed on the differential output shaft 62, and the brake 65 (see FIGS. 3 and 5) performs a braking operation by operating a brake pedal 230 (see FIG. 6) located on the rear side of the steering column 234. It is configured as follows. On the other hand, when the steering angle of the steering handle 9 is detected, the brake cylinder 68 is operated by the left and right autobrake solenoid valves 67a and 67b, the brake 65 is automatically braked, and a turning run such as a U-turn is performed. It is configured.

  A differential gear mechanism 58 disposed in the rear chamber 35 has a differential lock mechanism (not shown) for stopping the differential operation (the right and left differential output shafts 62 are always driven at a constant speed). Is provided. When the lock pin provided in the differential gear case 61 so as to freely enter and exit is engaged with the differential gear by operating a differential lock lever (or pedal) (not shown), the differential gear is fixed to the differential gear case 61, The differential function of the dynamic gear is stopped, and the left and right differential output shafts 62 are driven at a constant speed.

  Next, a configuration for switching between the two-wheel drive and the four-wheel drive of the front and rear wheels 3 and 4 will be described. As shown in FIG. 3, the front wheel drive case 69 provided on the front side wall member 32 of the mission case 17 is provided with a front wheel input shaft 72 and a front wheel output shaft 73. The front wheel input shaft 72 is connected to the auxiliary transmission shaft 50 through gears 70 and 71 so that power can be transmitted. Further, the front wheel output shaft 73 is driven by a four-wheel drive gear clutch 75 connected to the front wheel output shaft 73 so as to rotate together with the front wheel output shaft 73 and a double speed hydraulic clutch 76. A double speed gear 77 connected to the wheel output shaft 73 so as to be integrally rotatable is fitted. The four-wheel drive gear 75 meshes with a gear 78 provided on the front wheel input shaft 72. The double speed gear 77 is also meshed with a gear 79 provided on the front wheel input shaft 72.

  Then, by operating a switching lever (not shown) between 2WD and 4WD to the 4WD side, the clutch cylinder 81 is operated by the 4WD hydraulic electromagnetic valve 80, and the 4WD hydraulic clutch 74 is continued. The front wheel input shaft 72 and the front wheel output shaft 73 are connected by a four-wheel drive gear 75 so that the front wheel 3 is driven together with the rear wheel 4.

  Next, a configuration for switching the double speed drive of the front wheel 3 will be described. As shown in FIG. 3, the clutch cylinder 83 is operated by the double-speed hydraulic solenoid valve 82 and the double-speed hydraulic clutch 76 is continued by detecting the U-turn (direction change at the headland in the field) of the steering handle 9. The front wheel input shaft 72 and the front wheel output shaft 73 are connected by the double speed gear 77, and the front wheel 3 is driven at a high speed about twice as high as the speed when the front wheel 3 is driven by the four-wheel drive gear 75. The wheel 3 is configured to be driven.

  As shown in FIG. 3, power is transmitted to the front wheels 3 between a front wheel transmission shaft 84 projecting rearward from the front axle case 13 and a front wheel output shaft 73 projecting forward from the front surface of the transmission case 17. The front wheel drive shaft 85 is connected. In addition, a differential gear mechanism 86 that transmits traveling driving force to the left and right front wheels 3 is disposed inside the front axle case 13.

  The differential gear mechanism 86 includes a ring gear 88 that meshes with a pinion 87 at the front end of the front wheel transmission shaft 84, a differential gear case 89 provided on the ring gear 88, and left and right differential output shafts 90. A front axle 92 is connected to the differential output shaft 90 by a final gear 91 or the like, and a front wheel 3 provided on the front axle 92 is driven. In addition, a power steering hydraulic cylinder 93 (see FIG. 5) is disposed on the outer surface of the front axle case 13 to change the traveling direction of the front wheel 3 to the left and right by the steering operation of the steering handle 9.

  As shown in FIG. 3, the working unit hydraulic pump 94 provided on the front side of the front side wall member 32 of the mission case 17 is for supplying hydraulic oil to the working unit lifting mechanism 20. The traveling hydraulic pump 95 is for supplying hydraulic oil to the transmissions of the transmission case 17 and the hydraulic cylinder 93 for power steering. In this case, the mission case 17 is used together as an oil tank. The hydraulic pumps 94 and 95 are configured to supply hydraulic oil inside the mission case 17.

  Next, a configuration for switching the driving speed of the PTO shaft 23 (four forward rotations and one reverse rotation) will be described. In the front chamber 34 of the transmission case 17, a PTO transmission gear mechanism 96 for transmitting power from the engine 5 to the PTO shaft 23 and a pump drive for transmitting power from the engine 5 to the hydraulic pumps 94 and 95. A shaft 97 is provided.

  As shown in FIG. 3, the PTO transmission gear mechanism 96 described in detail later includes a PTO counter shaft 98 and a PTO transmission output shaft 99. A PTO input gear 101 connected by a PTO hydraulic clutch 100 is fitted on a PTO counter shaft 98. An input side gear 102 provided on the main transmission input shaft 27 and an output side gear 103 of the pump drive shaft 97 are meshed with the PTO input gear 101, and the pump drive shaft 97 is connected to the main transmission input shaft 27.

  Then, by continuing the operation of the PTO clutch lever (not shown), the clutch cylinder 105 is operated by the PTO clutch hydraulic solenoid valve 104 (see FIGS. 5 and 7), and the PTO hydraulic clutch 100 is continued, and the main shift input is performed. The shaft 27 and the PTO counter shaft 98 are configured to be connected by the PTO input gear 101.

  The PTO speed change output shaft 99 is fitted with a first gear 106, a second gear 107, a third gear 108, a fourth gear 109, and a reverse gear 110 for PTO output (see FIG. 3). ).

  A shift shifter 111 is supported on the PTO shift output shaft 99 by a spline so as to be movable. The gears 106 to 110 are configured to be selectively connected to the PTO shift output shaft 99 by a shift shifter 111. The transmission shifter 111 is engaged with a transmission arm 112 connected to a PTO transmission lever 224 (see FIG. 6). Then, by the shift operation of the PTO shift lever 224, the shift shifter 111 moves linearly along the axis of the PTO shift output shaft 99 in the shift arm 112, and any one of the gears 106 to 110 is alternatively selected. It is selected and connected to the PTO speed change output shaft 99 (see FIG. 3). Accordingly, the first to fourth speed and reverse PTO shift outputs are transmitted from the PTO shift output shaft 99 to the PTO shaft 23 via the gears 113 and 114.

  It should be noted that an electromagnetic pickup type main transmission output shaft rotation sensor 116 (see FIG. 7) for detecting the rotation of the main transmission output gear 37 is installed on the rotation detection gear 115 provided on the reverse rotation shaft 39 so as to be opposed to the hydraulic pressure. The main transmission output shaft rotation sensor 116 detects the output rotation speed of the continuously variable transmission 29. Further, an electromagnetic pickup type vehicle speed sensor 117 (see FIG. 7) for detecting the rotation of the gear 78 is installed in the vicinity of the gear 78 of the front wheel input shaft 72. The traveling speed (vehicle speed) of the traveling machine body 2 is detected from the rotation of the front wheel input shaft 72 and the auxiliary transmission shaft 50 detected by the vehicle speed sensor 117.

  Next, the speed change operation of the hydraulic continuously variable transmission 29 by the main speed change hydraulic cylinder 556 will be described with reference to FIGS.

  The main transmission hydraulic cylinder 556 is operated by switching the forward clutch solenoid valve 46 or the reverse clutch solenoid valve 48 (see FIGS. 3 and 7) corresponding to the depression pedal 232 or the reverse pedal 233 described later. To do. Then, the main transmission operation of the hydraulic continuously variable transmission 29 is performed by changing the inclination angle of the pump swash plate in conjunction with the upward or downward movement of the piston of the main transmission hydraulic cylinder 556.

  The forward clutch solenoid valve 46, the reverse clutch solenoid valve 48, the four-wheel drive hydraulic solenoid valve 80, the double speed hydraulic solenoid valve 82, and the PTO clutch hydraulic solenoid valve 104 shown in FIGS. 3 and 5 are the solenoid valves 46, 48, When 80, 82, and 104 are appropriately controlled, the corresponding clutch cylinders 47, 49, 81, 83, and 105 are operated, and the hydraulic clutches 40, 42, 74, 76, and 100 shown in FIG. Are configured to be switched and driven.

  Next, with reference to FIGS. 3 and 4, the speed change structure of the traveling auxiliary transmission gear mechanism 30 will be described in detail. As shown in FIG. 4, the auxiliary transmission hydraulic cylinder 55 has a double-acting structure in which a piston rod 661 is provided on one side of the piston 660. The auxiliary transmission hydraulic cylinder 55 is formed with a first cylinder chamber 662 in which a piston rod 661 is provided and the other second cylinder chamber 663. An auxiliary transmission shifter 665 is connected to the tip of the piston rod 661 via a shift arm 664. The low speed clutch 56 or the high speed clutch 57 is continued by the auxiliary transmission shifter, and the auxiliary transmission shaft 50 is driven at a low speed or a high speed.

  The first cylinder chamber 662 is in direct communication with the discharge side of the traveling hydraulic pump 95. The second cylinder chamber 663 communicates with the discharge side of the traveling hydraulic pump 95 via a two-position three-port high-speed clutch solenoid valve 666. The high speed clutch solenoid valve 666 includes a speed change solenoid 667. When the high speed clutch electromagnetic valve 666 is switched by the speed change solenoid 667 and the second cylinder chamber 663 is communicated to the discharge side of the traveling hydraulic pump 95 via the high speed clutch electromagnetic valve 666, the difference in pressure receiving pressure on both sides of the piston 660 Thus, the piston 660 moves in the direction in which the piston rod 661 protrudes, and the high speed clutch 57 is continued to drive the auxiliary transmission shaft 50 at high speed (see FIG. 3).

  Next, traveling control (shift control) of the work vehicle in the present embodiment will be described with reference to FIGS. 6 and 7. A controller 210 as a control means having a ROM storing a control program and a RAM storing various data is connected to a battery (not shown) via a power application key switch 211. The key switch 211 is connected to a starter 212 for starting the engine 5.

  An electronic governor controller 213 that controls the rotation of the engine 5 is connected to the controller 210. The electronic governor controller 213 includes an engine governor 214 that adjusts the fuel of the engine 5, an engine rotation sensor 215 that detects the number of revolutions of the engine 5, a throttle potentiometer 217 that detects the operation position of the throttle lever 206 serving as a main transmission operation means, A throttle solenoid (not shown) for adjusting the position of a fuel adjustment rack (not shown) in the engine governor 214 is connected.

  When the operator manually operates the throttle lever 206, the electronic governor controller 213 controls the throttle solenoid (not shown) so that the detected value of the throttle potentiometer 217 (set rotation speed at the throttle lever 206) matches the engine rotation speed. The control for automatically adjusting the position of the fuel adjustment rack at is executed. As a result, the engine speed is maintained at the speed corresponding to the position of the throttle lever 206 regardless of the load variation.

  The controller 210 also includes various output solenoid valves, that is, a forward clutch solenoid valve 46 for the forward hydraulic clutch 40, a reverse clutch solenoid valve 48 for the reverse hydraulic clutch 42, and a high speed for the travel auxiliary transmission hydraulic cylinder 55. For the proportional solenoid valve 203, the left and right brake pedal solenoid valves 67a and 67b, and the PTO clutch 100 for operating the main transmission hydraulic cylinder 556 in proportion to the depression amount of the clutch solenoid valve 666, the forward pedal 232 and the reverse pedal 233 The PTO clutch hydraulic solenoid valve (proportional control valve) 104 and the like are connected.

  Further, the controller 210 includes various sensors and switches of the input system, that is, a steering potentiometer 218 for detecting the rotation amount (steering angle) of the steering handle 9, and an operation amount (depression) of a forward pedal 232 which is an example of a gear ratio operation means. Forward potentiometer 219 that detects the amount), reverse potentiometer 220 that detects the amount of operation (depression amount) of the reverse pedal 233, which is also an example of the gear ratio operation means, and the shift of the output speed of the main transmission output shaft 36 relative to the engine speed. Sub-transmission as sub-transmission operation means for switching the output range of the transmission sub-transmission gear mechanism 30 between high speed and low speed, and a gear ratio setting device 221 for switching the ratio range (hereinafter referred to as a gear ratio pattern) in multiple stages. Changeover switch 222, main transmission output shaft rotation sensor 116 for detecting the output rotational speed of the main transmission output shaft 36, front Control signals from a vehicle speed sensor 117 that detects the rotational speed (traveling speed) of the wheels 3 and 4, a brake pedal switch 231 that detects whether or not the brake pedal 230 is depressed, and a remote controller 131 (transmitter) for remote control of the working unit. And a forward / reverse changeover switch 130 as forward / reverse operation means that can be switched in three stages of a forward position, a neutral position, and a reverse position.

  As shown in FIG. 6, in the present embodiment, the steering handle 9 as steering means is disposed on the steering column 234 located in front of the steering seat 8, and the traveling body 2 is mounted on the rear surface side of the steering column 234. A brake pedal 230 for performing a braking operation is disposed. On the right side of the steering column 234, a throttle lever 206 for adjusting the rotational speed of the engine 5, a pedal lock lever 128 for maintaining the forward pedal 232 and the reverse pedal 233 in a substantially constant posture, and the like are disposed. A forward pedal 232 and a reverse pedal 233 are arranged in parallel on the right side of the steering column 234.

  A PTO speed change lever 224 for selecting and operating each of the gears 106 to 110 fitted on the PTO speed change output shaft 99 is disposed on the left column of the control seat 8. A differential lock pedal 225 is disposed in front of the left column. On the right side column of the control seat 8, a work equipment lifting lever 259 for manually changing and adjusting the height position of a working unit (not shown) such as a tiller is disposed on the right side column of the control seat 8. Has been.

  On the left and right sides of the control seat 8 are provided longitudinal armrests 140, 140 for placing the arms and elbows of the operator seated on the control seat 8. In FIG. 6, the armrest 140 on the right side in the traveling direction is indicated with a symbol a, and the armrest 140 on the left side in the traveling direction is indicated with a symbol b. The rear end portions of the armrests 140 are pivotally attached to a horizontally long frame member located behind the control seat 8 so as to be flipped up by a horizontal shaft 144. The armrest 140 is normally held in a substantially horizontal posture with respect to the seating surface of the control seat 8.

  A storage portion 141a that opens upward is provided in the longitudinal middle portion of the right armrest 140a. The storage portion 141a is covered with an upper surface lid 142a configured to be openable and closable. A remote controller 131 (transmitter) for remote operation of the working unit is accommodated in the storage unit 141a. The remote controller 131 is provided with various dials and the like for remotely adjusting the left and right tilt angles and tilling depths of the working unit.

  When various dials are operated after the remote controller 131 is turned on and operated, a command signal corresponding to the operation is transmitted to the receiver 132 and input from the receiver 132 to the controller 210. The controller 210 performs control to adjust the right / left tilt angle and tillage depth of the working unit according to the input signal. An accessory box 143 for an operator to store a water bottle or the like is also provided below the right armrest 140a.

  Of the right armrest 140a (the armrest 140a located on the same side as the throttle lever 206), a portion where the operator's arm can be operated with a finger, that is, a portion on the front end side of the upper lid 142a of the right armrest 140a A gear ratio setting device 221 for switching the gear ratio pattern in multiple stages, a sub gear change switch 222 as a sub gear operating means, and a forward / reverse selector switch 130 as a forward / backward operating means are provided. .

  The transmission ratio setting device 221 is a dial type variable resistor. The gear ratio setting unit 221 is configured to adjust and set the rate of change of the gear ratio corresponding to the amount of depression of the forward pedal 232 and the reverse pedal 233 by changing the position of the knob (pointer) in stages. ing.

  As the gear ratio patterns that can be selected by the gear ratio setting unit 221, there are prepared a plurality of types in which the gear ratio increases in proportion to the amount of depression of the forward pedal 232 and the reverse pedal 233 increasing. The plurality of types of gear ratio patterns are set according to the type of farm work and the field conditions (soil quality, paddy field, field land, etc.). A group of speed ratio patterns is stored in advance in the ROM or the like of the controller 210 in a function table format or a map format.

  When the operator appropriately selects the scale of the gear ratio setting unit 221, any one pattern is set (instructed) from among a plurality of types of gear ratio patterns. Thus, the hydraulic continuously variable transmission is configured so that the actual (real) gear ratio is within a predetermined percentage of the target gear ratio while the engine speed of the tractor 1 is kept substantially constant regardless of the fluctuation of the load. The gear ratio of 29 is controlled.

  When the scale is neutral, the transmission ratio setting unit 221 sets the output of the hydraulic continuously variable transmission 29 to substantially zero (the transmission ratio is 0) regardless of the depression amount of the forward pedal 232 and the reverse pedal 233. Configured to maintain.

  The auxiliary transmission changeover switch 222 as an auxiliary transmission operation means is a single-acting push switch that locks at the pressed position when the switch is pressed once, and returns to the original position when pressed again.

  When the sub-shift is switched from a low speed to a high speed by depressing the sub-shift switch 222 once, the low speed clutch 56 is in a power cut-off state and the high speed clutch 57 is in a power connection state in the sub shift hydraulic cylinder 55. Then, the high speed gear 54 is connected to the auxiliary transmission shaft 50 so as to rotate integrally, and a high speed driving force is output from the auxiliary transmission shaft 50 to the front wheels 3 and the rear wheels 4.

  When the sub-shift is switched from the high speed to the low speed by depressing the sub-shift switch 222 once depressed, the high-speed clutch 57 enters the power cut-off state and the low-speed clutch 56 enters the power connection state. . Then, the low speed gear 52 is connected to the auxiliary transmission shaft 50 so as to rotate integrally, and a low speed driving force is output from the auxiliary transmission shaft 50 to the front wheels 3 and the rear wheels 4.

  The forward / reverse changeover switch 130 as the forward / reverse operation means is for switching the traveling direction of the traveling machine body 2 between forward and reverse. As the forward / reverse selector switch 130 of this embodiment, a slide switch type that can be switched in three stages of a forward position, a neutral position, and a reverse position is employed.

  When the forward / reverse selector switch 130 is slid to the forward position, the reverse hydraulic clutch 42 is in a power cut-off state, and the forward hydraulic clutch 40 is in a power connection state. Then, the main transmission output gear 37 and the travel counter shaft 38 are connected in a state where power can be transmitted by the forward gear 41 (see FIG. 3), and finally the front transmission wheel 3 and the rear wheels 4 are connected from the auxiliary transmission shaft 50. On the other hand, the traveling driving force in the direction of moving the traveling machine body 2 forward is output.

  When the forward / reverse selector switch 130 is slid to the reverse position, the forward hydraulic clutch 40 is in a power cut-off state, and the reverse hydraulic clutch 42 is in a power connection state. Then, the main transmission output gear 37 and the travel counter shaft 38 are connected in a state where power can be transmitted by the reverse gear 44, the reverse output gear 45, and the reverse gear 43 (see FIG. 3). A traveling driving force in the direction of moving the traveling machine body 2 backward is output from the transmission shaft 50 to the front wheels 3 and the rear wheels 4.

  When the forward / reverse selector switch 130 is in a neutral position between the forward position and the reverse position, both the forward and reverse hydraulic clutches 40 and 42 are disconnected, and the main shift output to the front wheel 3 and the rear wheel 4 is released. The travel driving force from the gear 37 is substantially zero (main clutch disengaged state).

  When the forward / reverse selector switch 130 is in a position other than the neutral position (forward or reverse position), the travel control by the switch operation has priority over the travel control by the forward and reverse pedals 232 and 233 being depressed. It is configured to be performed.

  With the above-described configuration, the forward / backward changeover switch 130 for placing the arm and elbow of the operator seated on the control seat 8 is provided on the right armrest 140a located on the right side of the control seat 8, for example, the traveling machine body 2 When switching the traveling direction to forward or backward, if the left hand holds the steering handle 9 and the right hand rests on the right armrest 140a, it will sit back and forth with the right hand while sitting slowly on the steering seat 8. The advance selector switch 130 can be easily operated. As described above, since the forward / reverse selector switch 130 having a high operation frequency is excellent in operability, the fatigue of the operator due to long-time work can be reduced.

  In the present embodiment, since the forward / reverse switching switch 130 is provided at the front end side of the right armrest 140a that can be operated with fingers when the operator's arm is placed, the right hand rests only on the right armrest 140a. The right hand can easily reach the forward / reverse selector switch 130 on the right armrest 140a. Therefore, the operability of the forward / reverse selector switch 130 is further improved.

  Further, not only the forward / reverse selector switch 130 but also the gear ratio setting unit 221 and the auxiliary gear change switch 222, which are frequently operated, are provided at the front end portion of the right armrest 140a. Since the right armrest 140a can be put together, the usability (operability) of these operating means groups is further enhanced.

  In the present embodiment, the forward / backward changeover switch 130 is provided on the right armrest 140a located on the right side of the control seat 8 on the right side of the throttle lever 206. , The left hand can hold the steering handle 9 (without releasing it) and operate the throttle lever 206 or the forward / reverse selector switch 130 with only the right hand, so that the steering handle 9 can be operated from one hand. There is no need to switch to the other hand. Therefore, this also contributes to improving the operability of operating means such as the throttle lever 206 and the forward / reverse selector switch 103 that are frequently operated.

  The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, the armrest 140 may be provided only on either the left or right side of the control seat 8. When the armrest 140 is provided on both the left and right sides of the control seat 8 as in the above-described embodiment, the various operation means described in the claims may be provided on either the left or right armrest 140. The various operation means may be switch type or lever type.

  In addition, the configuration of each unit is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is a side view of a farm tractor. It is the perspective view which looked at the tractor from diagonally backward. It is a skeleton figure of a power transmission system. It is a hydraulic circuit diagram of a hydraulic continuously variable transmission. It is a hydraulic circuit diagram of a tractor. It is a top view of a cabin. It is a functional block diagram of a control means.

Explanation of symbols

5 Engine 8 Control seat 17 Mission case 27 Main transmission input shaft 29 Hydraulic continuously variable transmission 36 as transmission mechanism 36 Main transmission output shaft 130 Forward / reverse switching switches 140a and 140b as forward / reverse operation means Armrest 206 As main transmission operation means Throttle lever 210 controller 221 speed change ratio setting device 222 auxiliary gear change switch 232 forward pedal 233 reverse pedal 556 main transmission hydraulic cylinder (transmission actuator)

Claims (4)

A work vehicle equipped with a speed change transmission mechanism that shifts output from an engine mounted on a traveling machine body and transmits the output to a traveling part or a working part,
An armrest for placing a seated person's arm or elbow is provided on at least one of the left and right sides of the control seat in the traveling aircraft body, and the armrest is operated to switch the traveling direction of the traveling aircraft body between forward and reverse. A working vehicle characterized in that a forward / reverse operation means is provided.   2. The work vehicle according to claim 1, wherein the forward / reverse operation means is provided in a portion of the armrest that can be operated with a finger when a seated person's arm is placed. 3.   A steering column having steering means for steering the traveling machine body is disposed in front of the steering seat, and a main speed change operating means for adjusting the engine speed on either the left or right side of the steering column. The work vehicle according to claim 1, wherein the forward / reverse operation means is provided on the armrest located on the same side of the control seat as the main speed change operation means.   A speed ratio setting device for switching the speed ratio range of the output speed of the speed change transmission mechanism to the engine speed in multiple stages, and a speed change operation of the output speed range of the speed change transmission mechanism between low speed and high speed. 4. The work vehicle according to claim 1, wherein at least one of the auxiliary transmission operation means is provided on the armrest. 5.

Images