Work vehicles

Abstract

To provide a work vehicle including a highly operable PTO gear change lever.SOLUTION: A work vehicle comprises: a case (40) including a gear change arm (42) for linking a gear change lever (16) and a variable-speed gearbox, on the lower side of the gear change lever (16); a spindle (41) extending in the longitudinal direction, on a front wall and a rear wall of the case (40); a body part (42A) for sliding the gear change arm (42) back and forth along the spindle (41) and rotationally turning around an axis of the spindle (41); a first groove extending in the longitudinal direction formed in an outer periphery of the body part (42A); and a first spherical body (51) fitted in the first groove and a first energizing member (52) for energizing the first spherical body (51) toward the first groove, provided in a part facing the first groove in an inner periphery of the case (40).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work vehicle equipped with a PTO shift lever on a steering section. [Background technology]

[0002] Conventionally, a known technology for work vehicles is to provide a speed change lever in front of the driver's seat to increase or decrease the output rotation of the PTO shaft and change the direction of the output rotation (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-112116 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology of Patent Document 1, the worker has to move his or her eyes from the front of the work vehicle to the shift lever in order to check the shift lever's position, which results in poor operability of the shift lever.

[0005] Therefore, the present invention aims to provide a work vehicle with a highly maneuverable shift lever, which allows the worker to grasp the movement position of the shift lever by the sensation transmitted to the fingertips without having to move his eyes from the front of the work vehicle to the shift lever. [Means for solving the problem]

[0006] The present invention, which has solved the above problems, is as follows. That is, the invention of claim 1 is a work vehicle having a bonnet (4) on which an engine (E) is mounted, a control section (5) on which an operator sits provided behind the bonnet (4), and a PTO shaft (6) extending in the front-rear direction to which the output rotation of the engine (E) is transmitted provided behind and below the control section (5), A speed change lever (16) for increasing or decreasing the output rotation of the engine (E) and for switching the output rotation direction is provided in front of a cockpit (11) of the control section (5), a speed change gearbox (31) for switching the engagement state of gears (70-74) with the speed change lever (16) is provided below the control section (5), a case (40) is provided below the speed change lever (16) and has a speed change arm (42) for connecting the speed change lever (16) and the speed change gearbox (31) housed therein, and a support shaft (41) extending in the front and rear directions is provided on the front and rear walls of the case (40), and the speed change arm (42) is attached to a main body (42A) that slides in the front and rear directions along the support shaft (41) and rotates around the axis of the support shaft (41) and a base portion of the speed change lever (16). The gear shift lever (16) is formed of a first extension portion (42B) extending from a main body portion (42A) and a second extension portion (42C) extending from the main body portion (42A) toward the gearbox (31), and a base portion of the gear shift lever (16) and an upper portion of the first extension portion (42B) are connected by a connecting member (46), and a tip end portion of the second extension portion (42C) and a shifter (61A, 64A) connected to gears (70-74) are connected to the gearbox (31). , 67A), a first groove (50) extending in the front-to-rear direction is formed on the outer periphery of the main body (42A), and a first spherical body (51) that fits into the first groove (50) and a first biasing member (52) that biases the first spherical body (51) toward the first groove (50) are provided at a portion of the inner periphery of the case (40) facing the first groove (50).

[0007] The invention described in claim 2 is the work vehicle described in claim 1, in which a guide plate (18) through which the speed change lever (16) is inserted is provided in front of the driver's seat (11), first to third guide grooves (18A to 18C) extending in the front-rear direction are formed in the guide plate (18) at a predetermined interval in the left-right direction, and a fourth guide groove extending in the left-right direction connecting the front-rear middle portions of the first to third guide grooves (18A to 18C) is formed, and when the speed change lever (16) is inserted into the second guide groove (18B) between the first guide groove (18A) and the third guide groove (18C), a first spherical body (51) fits into the first groove (50).

[0008] The invention described in claim 3 is a work vehicle described in claim 1 or 2, in which a second groove (55) extending circumferentially is formed on the outer periphery of the support shaft (41), and a second spherical body (56) that fits into the second groove (55) and a second biasing member (57) that biases the second spherical body (56) toward the second groove (55) are provided at a portion on the inner periphery of the main body portion (42A) facing the second groove (55).

[0009] The invention described in claim 4 is the work vehicle described in claim 3, wherein when the shift lever (16) is inserted into the fourth guide groove (18D), the second sphere (56) fits into the second groove (55).

[0010] A fifth aspect of the present invention is the work vehicle according to the first aspect, wherein the connecting member (46) is a double ball joint. [Effects of the Invention]

[0011] According to the invention of claim 1, a speed change lever (16) for increasing / decreasing the output rotation of the engine (E) and switching the output rotation direction is provided in front of the cockpit (11) of the control section (5), a speed change gear box (31) for switching the engagement state of the gears (70-74) with the speed change lever (16) is provided below the control section (5), and a speed change gear box (31) for linking the speed change lever (16) and the speed change gear box (31) is provided below the speed change lever (16). A case (40) is provided with a speed change arm (42) housed therein, and a support shaft (41) extending in the front-rear direction is provided on the front wall and rear wall of the case (40), and the speed change arm (42) is made up of a main body portion (42A) that slides in the front-rear direction along the support shaft (41) and rotates around the axis of the support shaft (41), a first extension portion (42B) that extends from the main body portion (42A) toward the base of the speed change lever (16), and a second extension portion (42B) that extends from the main body portion (42A) toward the speed change gear box (31). The gear shift lever (16) is connected to the upper part of the first extending portion (42B) by a connecting member (46). The tip of the second extending portion (42C) is engaged with a shifter (61A, 64A, 67A) connected to the gears (70-74). A first groove (50) extending in the front-rear direction is formed on the outer periphery of the main body (42A). The first groove (50) faces the first groove (50) on the inner periphery of the case (40). A first spherical body (51) that fits into the first groove (50) and a first biasing member (52) that biases the first spherical body (51) toward the first groove (50) are provided at a position where the shift lever (16) is inserted. Therefore, the change in sliding resistance when the first spherical body (51) moves from the first groove (50) to the outer periphery of the main body (42A) is transmitted to the fingertips of the operator, allowing the operator to grasp the left-right movement position of the shift lever (16), thereby improving the operability of the shift lever (16).

[0012] According to the invention of claim 2, in addition to the effects of the invention of claim 1, a guide plate (18) through which the speed change lever (16) is inserted is provided in front of the cockpit (11), first to third guide grooves (18A to 18C) are formed in the guide plate (18) at a predetermined interval in the left-right direction and extending in the front-rear direction, and a fourth guide groove is formed in the left-right direction and connecting the middle parts of the first to third guide grooves (18A to 18C) in the front-rear direction, and when the speed change lever (16) is inserted into the second guide groove (18B) between the first guide groove (18A) and the third guide groove (18C), the first spherical body (51) fits into the first groove (50), making it possible for the operator to easily recognize that the speed change lever (16) is moving along the second guide groove (18B) formed in the middle part in the left-right direction.

[0013] According to the invention of claim 3, in addition to the effects of the invention of claim 1 or 2, a second groove (55) extending in the circumferential direction is formed on the outer periphery of the support shaft (41), and a second spherical body (56) that fits into the second groove (55) and a second biasing member (57) that biases the second spherical body (56) toward the second groove (55) are provided at a portion of the inner periphery of the main body (42A) that faces the second groove (55). Therefore, the change in sliding resistance when the second spherical body (56) moves from the second groove (55) to the outer periphery of the main body (42A) is transmitted to the operator's fingertips, allowing the operator to grasp the forward / backward movement position of the shift lever (16), further improving the operability of the shift lever (16).

[0014] According to the invention of claim 4, in addition to the effect of the invention of claim 3, when the shift lever (16) is inserted into the fourth guide groove (18D), the second spherical body (56) fits into the second groove (55), making it easier for the operator to recognize that the shift lever (16) is moving along the fourth guide groove (18D) formed in the middle in the front-to-rear direction.

[0015] According to the invention of claim 5, in addition to the effect of the invention of claim 1, since the connecting member (46) is a double ball joint, the main body (42A) can be efficiently moved in the front-rear direction and the circumferential direction of the support shaft (41) by operating the speed change lever (16). [Brief explanation of the drawings]

[0016] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. 4 is an explanatory diagram of a PTO operation guide plate. [Figure 4] FIG. 10 is an explanatory diagram of an operation guide plate. [Figure 5] 1 is a transmission diagram of the engine output rotation. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 2 is a rear view of the PTO shift lever. [Figure 9] FIG. 2 is a plan view of the PTO shift lever. [Figure 10] FIG. 2 is an enlarged right side view of the PTO shift lever. [Figure 11] FIG. 1 is a perspective view of a PTO transmission gearbox. [Figure 12] FIG. 2 is an explanatory diagram of a PTO transmission gear box. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. [Figure 16] FIG. 10 is a perspective view of another shift lever. [Figure 17] FIG. 10 is a front view of another shift lever. [Figure 18] FIG. 10 is a left side view of another shift lever. DETAILED DESCRIPTION OF THE INVENTION

[0017] As shown in FIG. 1, a work vehicle such as a tractor has a pair of left and right front wheels 2 provided at the front lower part of a body frame 1, and a pair of left and right rear wheels 3 provided at the rear lower part of the body frame 1.

[0018] A bonnet 4 that houses the engine E is provided at the front upper part of the body frame 1, and a control section 5 on which an operator sits is provided behind the bonnet 4. A PTO shaft 6 that extends in the fore-and-aft direction and to which the output rotation of the engine E is transmitted is provided below and behind the control section 5, and a work implement 7 such as a manure spreader that spreads compost on a field is connected to the rear of the PTO shaft 6.

[0019] A steering wheel 12 is provided in front of a driver's seat 11 in the control section 5, and a clutch pedal 14 is provided below a steering column 13 that houses a steering shaft that supports the steering wheel 12. In addition, fenders 15 that cover the tops of the rear wheels 3 are provided on both left and right sides of the driver's seat 11.

[0020] As shown in Figure 2, a PTO shift lever (referred to as "shift lever" in the claims) 16 for increasing or decreasing the output rotation of the PTO shaft 6 is provided on the front right side of the cockpit 11, and a shift lever 17 for increasing or decreasing the output rotation transmitted to the rear wheel 3 is provided on the left side of the cockpit 11.

[0021] As shown in Figure 3, PTO shift lever 16 is inserted through PTO operation guide plate (referred to as "guide plate" in the claims) 18. PTO operation guide plate 18 is formed with three operation guide grooves 18A-18C that extend in the front-rear direction at a predetermined interval in the left-right direction, and an operation guide groove (referred to as "fourth guide groove" in the claims) 18D that extends in the left-right direction and connects the middle portions of operation guide grooves 18A-18C in the front-rear direction. This allows the operator to increase or decrease the output rotation of PTO shaft 6 by moving PTO shift lever 16 along operation guide groove 18A, etc.

[0022] When the PTO shift lever 16 is moved to the front of the operation guide groove (the "first guide groove" in the claims) 18A, the output rotation of the PTO shaft is reduced to the lowest speed, first gear. When the PTO shift lever 16 is moved to the rear of the operation guide groove 18A, the output rotation of the PTO shaft is increased to second gear. When the PTO shift lever 16 is moved to the front of the operation guide groove (the "second guide groove" in the claims) 18B, the output rotation of the PTO shaft is increased to third gear. When the PTO shift lever 16 is moved to the rear of the operation guide groove 18B, the output rotation of the PTO shaft is increased to the highest speed, fourth gear. Furthermore, when the PTO shift lever 16 is moved to the rear of the operation guide groove (the "third guide groove" in the claims) 18C, the direction of the output rotation of the PTO shaft is reversed. Figure 3 shows the PTO shift lever 16 in fourth gear.

[0023] As shown in Figure 4, the gearshift lever 17 is inserted into an operation guide plate 19. The operation guide plate 19 is formed with two operation guide grooves 19A and 19B that extend in the front-rear direction at a predetermined left-right interval, and an operation guide groove 19C that extends in the left-right direction and connects the middle portions of the operation guide grooves 19A and 19B in the front-rear direction. This allows the operator to increase or decrease the output rotation transmitted to the rear wheel 3 by moving the gearshift lever 17 along the operation guide groove 19A, etc.

[0024] When the shift lever 17 is moved to the front of the operation guide groove 19A, the output rotation transmitted to the rear wheel 3 is reduced to the lowest speed, first gear, when the shift lever 17 is moved to the rear of the operation guide groove 19A, the output rotation transmitted to the rear wheel 3 is increased to second gear, and when the shift lever 17 is moved to the rear of the operation guide groove 19B, the output rotation transmitted to the rear wheel 3 is increased to the highest speed, third gear. Note that Figure 4 shows the state when the shift lever 17 is moved to third gear.

[0025] As shown in Fig. 5, the output rotation of the engine E is transmitted to a continuously variable transmission 20. The output rotation, which has been increased or decreased and the output rotation direction changed by the continuously variable transmission 20, which is equipped with a hydraulic pump P and a motor M, is output from a first output shaft 20A and a second output shaft 20B.

[0026] The output rotation of the first output shaft 20A is transmitted to the input shaft of a speed change gear box 22 via a clutch 21. The clutch 21 is switched between engagement and disengagement by stepping on the clutch pedal 14. The output rotation, which has been increased or decreased in speed or has its output rotation direction switched by the speed change gear box 22, is output from the output shaft.

[0027] The output rotation of the output shaft of the speed change gearbox 22 is transmitted via a bevel gear to the input shaft of a differential gear 23 for the rear wheels, and then via a gear to a rotating shaft 26. The output rotation, which has been increased or decreased by the differential gear 23, is output to left and right drive shafts 24, and the output rotation of the drive shafts 24 is transmitted to a pair of left and right rear wheels 3 via a pair of left and right wheels.

[0028] The output rotation of the rotary shaft 26 is transmitted to the input shaft of a differential gear 28 for the front wheels via a four-wheel drive clutch 27. The clutch 27 is switched between engagement and disengagement by operating a four-wheel drive lever (not shown) provided on the fender 15. The output rotation, which has been increased or decreased by the differential gear 28, is output to left and right drive shafts 29, and the output rotation of the left and right drive shafts 29 is transmitted to a pair of left and right front wheels 2 via a pair of left and right wheels.

[0029] The output rotation of the second output shaft 20B is transmitted to the input shaft of a PTO speed change gear box (referred to as "speed change gear box" in the claims) 31 via a PTO clutch 30. The clutch 30 is switched between engagement and disengagement by operating a clutch lever (not shown) provided on the operating section 5. The output rotation, which has been increased or decreased and the output rotation direction switched by the PTO speed change gear box 31, is output from the output shaft.

[0030] The output rotation of the output shaft of the PTO speed change gearbox 31 is transmitted to the rotary shaft 32, and the output rotation of the rotary shaft 32 is transmitted to the PTO shaft 6 via gears.

[0031] As shown in FIG. 6, a PTO shift lever 16 is mounted on the rear part of the right wall of the transmission case 35, and a shift lever 17 is mounted on the rear part of the left wall of the transmission case 35. Further, a PTO shift gear box 31 in which gears are switched by operating the PTO shift lever 16 is installed inside the rear part of the transmission case 35, and a shift gear box 22 in which gears are switched by operating the shift lever 17 is installed inside the front part of the transmission case 35.

[0032] <PTO shift lever> As shown in FIGS. 7 to 9, support shafts 41 made of round steel extending in the front-rear direction are installed on the front wall and the rear wall of a case 40 with an open left wall. A shift arm 42 that is rotatably and slidably supported by the support shaft 41 is externally fitted to the support shaft 41.

[0033] The shift arm 42 is formed of a cylindrical main body part 42A externally fitted to the outer peripheral part of the support shaft 41, a cylindrical first extension part 42B extending upward from the main body part 42A, and a second extension part 42C having a rectangular longitudinal section extending leftward from the main body part 42A. Further, a tapered hollow part that expands from the lower side to the upper side in the longitudinal section is formed in the upper part of the first extension part 42B. Furthermore, an operation member 43 formed thinner than the second extension part 42C having a rectangular longitudinal section is provided at the tip of the second extension part 42C.

[0034] A cylindrical connecting part 45 is provided on the upper wall of the case 40. A hollow part is formed in the connecting part 45, and a tapered hollow part that expands from the upper side to the lower side in the longitudinal section is formed in the lower part of the hollow part. Further, a flexible bellows 45A having an opening formed at the top is provided in the upper part of the connecting part 45.

[0035] A double ball joint (referred to as a "connecting member" in the claims) 46 is fitted into the lower hollow portion of connecting portion 45 and the upper hollow portion of first extension portion 42B of speed change arm 42. Double ball joint 46 is formed from rod 46A made of round steel, ball 46B made of a steel ball rotatably supported on the upper side of rod 46A, and ball 46C made of a steel ball rotatably supported on the lower side of rod 46A. Note that although a double ball joint is used as the connecting member in this embodiment, a universal joint can also be used.

[0036] The lower part of PTO shift lever 16 is connected to the upper part of ball 46B via locking member 47 formed by a compression spring or the like. As a result, when the operator moves PTO shift lever 16 in the front-to-rear direction along operation guide grooves 18A-18C of PTO operation guide plate 18, main body 42A of shift arm 42 can be moved in the front-to-rear direction along support shaft 41. Furthermore, when the operator moves PTO shift lever 16 in the left-to-right direction along operation guide groove 18D of PTO operation guide plate 18, main body 42A of shift arm 42 can be rotated about support shaft 41, and operating member 43 formed at the tip of second extension portion 42C can be moved in the up-and-down direction.

[0037] A guide plate 44 is provided at the bottom of the left wall of the case 40, extending leftward and then upward.

[0038] As shown in Figure 10, a first groove 50 extending in the front-to-rear direction is formed on the outer periphery of the main body 42A of the speed change arm 42, and a portion located below the support shaft 41 at the bottom of the case 40 is provided with a first spherical body 51 made of a steel ball that fits into the first groove 50, and a first biasing member 52 made of a spring or the like that biases the first spherical body 51 toward the main body 42A of the speed change arm 42 and the first groove 50 of the main body 42A.

[0039] When the operator moves PTO shift lever 16 into operation guide groove 18B of PTO operation guide plate 18, first spherical body 51 fits into first groove 50 of main body 42A. When the operator moves PTO shift lever 16 to the right to move PTO shift lever 16 from operation guide groove 18B to operation guide groove 18A, or when the operator moves PTO shift lever 16 to the left to move PTO shift lever 16 from operation guide groove 18B to operation guide groove 18C, first spherical body 51 that was fitted into first groove 50 of main body 42A moves from first groove 50 to the outer periphery of main body 42A. This changes the sliding resistance, and the change in sliding resistance is transmitted to the operator via PTO shift lever 16, so the operator can recognize the left-right position of PTO shift lever 16 without visually checking PTO shift lever 16.

[0040] A second groove 55 extending in the circumferential direction is formed on the outer periphery of the support shaft 41, and a second spherical body 56 consisting of a steel ball that fits into the second groove 55 and a second biasing member 57 consisting of a spring or the like that biases the second spherical body 56 toward the outer periphery of the support shaft 41 and the second groove 55 of the support shaft 41 are provided on the upper part of the inner periphery of the main body 42A of the speed-change arm 42.

[0041] When the operator moves the PTO shift lever 16 into the operation guide groove 18D of the PTO operation guide plate 18, the second ball 56 fits into the second groove 55 of the support shaft 41. When the operator moves the PTO shift lever 16 forward, for example, from the middle portion of the operation guide groove 18B to the front, or when the operator moves the PTO shift lever 16 from the middle portion of the operation guide groove 18B to the rear, the second ball 56 that was fitted into the second groove 55 of the support shaft 41 moves from the second groove 55 to the outer periphery of the support shaft 41. This changes the sliding resistance, and the change in sliding resistance is transmitted to the operator via the PTO shift lever 16, so the operator can recognize the position of the PTO shift lever 16 in the front-to-rear direction without visually checking the PTO shift lever 16.

[0042] As shown in Figure 11, the guide plate 44 is formed with three guide grooves 44A to 44C extending in the front-to-rear direction at a predetermined interval in the vertical direction, and a guide groove 44D extending in the vertical direction that connects the middle portions of the guide grooves 44A to 44C in the front-to-rear direction.

[0043] When the operator moves the PTO shift lever 16 to the operation guide groove 18A of the PTO operation guide plate 18, the operating member 43 of the second extension portion 42C of the shift arm 42 moves to the guide groove 44A of the guide plate 44; when the operator moves the PTO shift lever 16 to the operation guide groove 18B, the operating member 43 moves to the guide groove 44B; and when the operator moves the PTO shift lever 16 to the operation guide groove 18C, the operating member 43 moves to the guide groove 44C. Furthermore, when the operator moves the PTO shift lever 16 to, for example, the front portion of the operation guide groove 18A of the PTO operation guide plate 18, the operating member 43 of the second extension portion 42C of the shift arm 42 moves to the front portion of the guide groove 44A of the guide plate 44; and when the operator moves the PTO shift lever 16 to the rear portion of the operation guide groove 18A, the operating member 43 moves to the rear portion of the guide groove 44A. This allows the operator to move the PTO shift lever 16, which is provided on the front right side of the cockpit 11, to move the operating member 43 of the shift arm 42. The operating member 43 is inserted through the guide groove 44A from the right side to the left side.

[0044] A support shaft 60 extending in the front-to-rear direction is mounted between the front flange 40A and the rear flange 40B of the case 40, and a variable speed fork 61 that moves in the front-to-rear direction along the support shaft 60 is fitted onto the outside of the support shaft 60. A rod 62 that moves in the front-to-rear direction is supported by the front flange 40A and the rear flange 40B of the case 40, and a variable speed fork arm 63 and a variable speed fork 64 are supported on the rod 62. A rod 65 that moves in the front-to-rear direction is supported by the front flange 40A and the rear flange 40B of the case 40, and a variable speed fork arm 66 and a variable speed fork 67 are supported on the rod 65.

[0045] The operating member 43 inserted into guide groove 44A of guide plate 44 engages with variable speed fork 61, and when the operating member 43 is moved forward or backward, the variable speed fork 61 also moves forward or backward. Furthermore, the operating member 43 inserted into guide groove 44B of guide plate 44 engages with variable speed fork arm 63, and when the operating member 43 is moved forward or backward, the rod 62 and variable speed fork 64 move forward or backward via the variable speed fork arm 63. Furthermore, the operating member 43 inserted into guide groove 44C of guide plate 44 engages with variable speed fork arm 66, and when the operating member 43 is moved forward or backward, the rod 65 and variable speed fork 67 move forward or backward via the variable speed fork arm 66.

[0046] As shown in Figure 12, a shifter 61A is provided between first gear 70 and second gear 71 along a rotary shaft 75. A shifter 64A is provided between third gear 72 and fourth gear 73 along a rotary shaft 75. A shifter 67A is provided behind reverse gear 74 along a rotary shaft 76 ...4A is provided between third gear 72 and fourth gear 73 along a rotary shaft 75. A shifter 64A is provided behind reverse gear 74 along a rotary shaft 76. A shifter 67A is provided behind reverse gear 74 along a rotary shaft 76. A shifter 64A is provided between third gear 72 and fourth gear 73 along a rotary shaft 75. A shifter 64A is provided behind fourth gear 73 along a rotary shaft 75. A shifter 67A is provided behind reverse gear 74 along a rotary shaft 76. A shifter 67A is provided behind reverse gear 74 along a rotary shaft 76. A shifter 64A is provided between third gear 72 and fourth gear 73 along a rotary shaft 75. A shifter 64A is provided behind fourth gear 73 along a rotary shaft 75. A shifter 64A is provided behind fourth gear 73 along a rotary shaft 75. A shifter 64A is provided behind fourth gear 73 along a rotary shaft 76. A shifter 67A is provided behind reverse gear 74 along a rotary shaft 76. A

[0047] The output rotation of the first gear 70 etc. is transmitted to the output shaft of the PTO transmission gearbox 31 via a gear supported on the output shaft of the PTO transmission gearbox 31, and the output rotation of the output shaft of the PTO transmission gearbox 31 is transmitted to the PTO shaft 6 via a gear supported on the PTO shaft 6. Note that reference numeral 31A denotes the input shaft of the PTO transmission gearbox 31, and reference numeral 31B denotes the output shaft of the PTO transmission gearbox 31.

[0048] This allows the operator to operate the PTO speed change lever 16 provided on the front right side of the operator's seat 11 to increase or decrease the output rotation of the PTO shaft and change the direction of the output rotation.

[0049] <Gear shift lever> As shown in FIG. 13, a speed change lever 17 for increasing or decreasing the output rotation transmitted to the rear wheel 3 is provided at the front of the left wall of the transmission case 35 .

[0050] 14 and 15, a case 80 attached to the left wall of transmission case 35 is provided with a transmission arm 81 that is rotatable and slidable in the left-right direction. Transmission arm 81 is formed from a cylindrical main body portion 81A made of round steel and extending in the left-right direction, a cylindrical extension portion 81B extending rearward and upward from the left portion of main body portion 81A, and an extension portion 81C with a rectangular cross section that extends downward from the right portion of main body portion 81A.

[0051] A hollow portion is formed in extension portion 81B, and a tapered hollow portion that widens from the bottom to the top in a vertical cross section is formed at the top of the hollow portion. In addition, the tip portion of extension portion 81C is formed thinner than the base portion.

[0052] A cylindrical connecting portion 82 having a hollow portion is provided at the base of gearshift lever 17, and a tapered hollow portion that widens from top to bottom in vertical cross section is formed at the bottom of the hollow portion of connecting portion 82. A flexible bellows 82A with an opening formed at its top is provided at the top of connecting portion 82. Connecting portion 82 is supported by the left wall of transmission case 35 via a support member 88.

[0053] Double ball joint 83 is fitted into the lower part of the hollow part of connecting part 82 and the upper part of the hollow part of extension part 81B of speed change arm 81. Double ball joint 83 is formed from rod 83A made of round steel, ball 83B made of a steel ball rotatably supported on the upper side of rod 83A, and ball 83C made of a steel ball rotatably supported on the lower side of rod 83A. The outer periphery of double ball joint 83 is covered with flexible bellows 84.

[0054] The lower part of the speed change lever 17 is connected to the upper part of the ball 83B via a locking member 85 formed by a compression spring or the like. As a result, when the operator moves the speed change lever 17 in the front-to-rear direction along the operation guide grooves 19A, 19B of the operation guide plate 19, the main body 81A of the speed change arm 81 can be moved in the left-to-right direction. Furthermore, when the operator moves the speed change lever 17 in the left-to-right direction along the operation guide groove 19C of the operation guide plate 19, the main body 81A of the speed change arm 81 can be rotated to move the tip of the extension part 81C in the front-to-rear direction.

[0055] A biasing member 86 such as a compression spring is provided on the outer periphery of main body 81A between the right surface of case 80 and the left surface of extension 81B. This causes the tip of extension 81C to move to the rear of guide groove 87A, which will be described later, when the operator releases his / her hand from shift lever 17 and stops operating shift lever 17.

[0056] A guide plate 87 is provided at the bottom of the right wall of case 40, extending upward and then toward the right. Two guide grooves 87A, 87B extending in the front-rear direction at a predetermined left-right interval, and a guide groove 87C extending in the left-right direction and connecting the middle portions of guide grooves 87A, 87B in the front-rear direction, are formed in guide plate 87. Note that operating member 43 is provided by inserting guide groove 44A etc. from the right side toward the left side.

[0057] When the operator moves the gearshift lever 17 into the operation guide groove 19A of the operation guide plate 19, the tip of the extension portion 82C of the gearshift arm 81 moves into the guide groove 87A of the guide plate 87, and when the operator moves the gearshift lever 17 into the operation guide groove 19B, the tip of the extension portion 82C moves into the guide groove 87B. Furthermore, when the operator moves the gearshift lever 17 to, for example, the front portion of the operation guide groove 19A of the operation guide plate 19, the tip of the extension portion 82C of the gearshift arm 81 moves into the front portion of the guide groove 87A of the guide plate 87, and when the operator moves the gearshift lever 17 to the rear portion of the operation guide groove 19A, the tip of the extension portion 82C moves to the rear portion of the guide groove 87A. This allows the operator to move the gearshift lever 17, which is provided on the left side of the cockpit 11, to move the extension portion 82C of the gearshift arm 81.

[0058] When the tip of the extension portion 82C is positioned in front of the guide groove 87A, the transmission gearbox 22 is in first gear and maintains the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the transmission gearbox 22; when the tip of the extension portion 82C is positioned in the rear of the guide groove 87A, the transmission gearbox 22 is in second gear and increases the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the transmission gearbox 22 by approximately 5 to 10%; and when the tip of the extension portion 82C is positioned in the rear of the guide groove 87B, the transmission gearbox 22 is in third gear and increases the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the transmission gearbox 22 by approximately 10 to 20%. This allows the operator to operate the speed change lever 17 located on the left side of the cockpit 11 to increase or decrease the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the speed change gear box 22, thereby increasing or decreasing the output rotation of the rear wheel 3.

[0059] <Other gear shift levers> Another gearshift lever is shown in Figure 16. The same members as those of the gearshift lever 17 described above are given the same reference numerals and the description thereof will be omitted.

[0060] 17 and 18, a rotatable transmission arm 91 is provided on a case 90 attached to the left wall of transmission case 35. Transmission arm 91 is formed from a cylindrical main body 91A made of round steel extending in the left-right direction, a plate-like extension 91B extending forward from the left portion of main body 91A, and an extension 91C with a rectangular cross section extending downward from the right portion of main body 91A.

[0061] A round rod-shaped connecting part 92 extending in the left-right direction is provided at the base of the gearshift lever 17, and a plate-shaped connecting plate 92A extending rearward is provided at the rear of the connecting part 92. The right part of the connecting part 92 is supported by the left wall of the transmission case 35 via a support member 95.

[0062] The rear portion of connecting plate 92A and the front portion of extending portion 91B are connected by a plate-shaped connecting plate 93. An upper portion of connecting plate 93 is rotatably supported by a pin 94A extending in the left-right direction and provided at the rear portion of connecting plate 92A, and a lower portion of connecting plate 93 is rotatably supported by a pin 94B extending in the left-right direction and provided at the front portion of extending portion 91B.

[0063] When using another type of shift lever 17, the operation guide plate 19 is different from the above-described operation guide plate 19 in that it has one operation guide groove 19A that extends in the front-rear direction.

[0064] When the operator moves the speed change lever 17 along the operation guide groove 19A of the operation guide plate 19 to the front of the operation guide groove 19A, the speed change gearbox 22 goes into first gear and maintains the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the speed change gearbox 22, and when the operator moves the speed change lever 17 to the front of the operation guide groove 19A, the speed change gearbox 22 goes into second gear and increases the speed of the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the speed change gearbox 22 by approximately 10 to 20. This allows the operator to operate the speed change lever 17 provided on the left side of the cockpit 11 to increase or decrease the output rotation transmitted from the first output shaft 20A of the continuously variable transmission 20 to the speed change gearbox 22, thereby increasing or decreasing the output rotation of the rear wheel 3. [Explanation of symbols]

[0065] 4. Bonnet 5 Control Unit 6 PTO shaft 11 Cockpit 16 PTO shift lever (shift lever) 18 PTO operation guide plate (guide plate) 18A Operation guide groove (first guide groove) 18B Operation guide groove (second guide groove) 18C Operation guide groove (third guide groove) 18D Operation guide groove (4th guide groove) 31 PTO variable speed gearbox (variable speed gearbox) 40 cases 41 Spindle 42 Speed ​​change arm 42A main body 42B 1st extension part 42C 2nd extension 46 Double ball joint (connecting member) 50 1st groove 51 First Sphere 52 first biasing member 55 2nd groove 56 Second Sphere 57 Second biasing member 61A Shifter 64A Shifter 67A Shifter 70 1st gear (gear) 71 2nd gear (gear) 72 3rd gear (gear) 73 4th gear (gear) 74 Reverse gear (gear)

Claims

1. A work vehicle having a bonnet (4) on which an engine (E) is mounted, a control section (5) on which an operator sits provided behind the bonnet (4), and a PTO shaft (6) extending in the fore-and-aft direction to transmit the output rotation of the engine (E) provided below and behind the control section (5), A speed change lever (16) for increasing / decreasing the output rotation of the engine (E) and switching the output rotation direction is provided in front of the cockpit (11) of the control section (5), A speed change gearbox (31) is provided below the operating section (5) and switches the engagement state of the gears (70 to 74) using the speed change lever (16). A case (40) is provided below the speed change lever (16) and houses a speed change arm (42) that connects the speed change lever (16) to a speed change gear box (31), A support shaft (41) extending in the front-rear direction is provided on the front wall and rear wall of the case (40), The speed change arm (42) is formed of a main body portion (42A) that slides in the front-rear direction along the support shaft (41) and rotates around the axis of the support shaft (41), a first extension portion (42B) that extends from the main body portion (42A) toward the base of the speed change lever (16), and a second extension portion (42C) that extends from the main body portion (42A) toward the speed change gear box (31), The base of the speed change lever (16) and the upper part of the first extension part (42B) are connected by a connecting member (46), The tip end of the second extension portion (42C) is engaged with a shifter (61A, 64A, 67A) connected to a gear (70 to 74), A first groove (50) extending in the front-rear direction is formed on the outer periphery of the main body portion (42A), A work vehicle characterized in that a first spherical body (51) that fits into the first groove (50) and a first biasing member (52) that biases the first spherical body (51) toward the first groove (50) are provided at a portion of the inner periphery of the case (40) facing the first groove (50).

2. A guide plate (18) through which the speed change lever (16) is inserted is provided in front of the cockpit (11), The guide plate (18) is formed with first to third guide grooves (18A to 18C) extending in the front-rear direction at predetermined intervals in the left-right direction, a fourth guide groove extending in the left-right direction and communicating with intermediate portions of the first to third guide grooves (18A to 18C) in the front-rear direction; 2. A work vehicle according to claim 1, wherein when the shift lever (16) is inserted into a second guide groove (18B) between the first guide groove (18A) and the third guide groove (18C), a first spherical body (51) fits into the first groove (50).

3. A second groove (55) extending in a circumferential direction is formed on the outer periphery of the support shaft (41), 3. A work vehicle according to claim 1 or 2, wherein a second spherical body (56) that fits into the second groove (55) and a second biasing member (57) that biases the second spherical body (56) toward the second groove (55) are provided at a portion of the inner periphery of the main body (42A) facing the second groove (55).

4. 4. A work vehicle according to claim 3, wherein when the speed change lever (16) is inserted into the fourth guide groove (18D), a second sphere (56) fits into the second groove (55).

5. 2. A work vehicle according to claim 1, wherein the connecting member (46) is a double ball joint.

Images