JP2001030942A - Mobile agricultural machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform switching to optimum rotating characteristics satisfactorily for working even in any field of a well-drained paddy field and an ill-drained paddy field, by providing a rotation decelerating means for deceleration proportional to the operating amount of a steering wheel and a deceleration/non- deceleration switching means for performing switching to a rotation non- decelerating means for shifting a vehicle speed only by operating a traveling gear shift lever. SOLUTION: A switching spool 187 is inserted into the hollow portion of a speed-change output shaft 119 so as to advance and retreat therefrom or therein and a clutch pin 188 engaged with the speed-change output shaft 119 is fixed onto the insertion end part of the spool 187. The notches 189, 190 which the clutch pin 188 is engaged with so as to be disengaged are formed in a decelerating output shaft 178 and a direct output shaft 179 respectively. The advance/retreat operation of the spool 187 permits selective coupling of the speed-change output shaft 119 with either of the decelerating output shaft 178 or the direct output shaft 179 through the clutch pin 188 and the notches 189, 190.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile agricultural machine such as a combine or tillage tractor or a field management vehicle for continuously cutting and threshing grain culms in a field.

[0002]

Conventionally, a traveling hydraulic continuously variable transmission mechanism for driving left and right traveling crawlers by operating a traveling speed change lever is steplessly changed in vehicle speed, and left and right is operated by operating a steering handle. There is a technique for changing the traveling path by changing the difference in driving speed of the traveling crawler steplessly. However, if the steering operation of the steering wheel alone is performed, the vehicle speed is maintained substantially constant between straight traveling and turning, and when performing a spin turn operation with a small turning radius, it is necessary to perform a deceleration operation with the traveling shift lever. Yes, it is necessary to perform both the steering handle operation and the traveling speed change lever operation when turning in the field headland. Therefore, by automatically decelerating the vehicle speed in conjunction with the steering wheel operation and automatically increasing the vehicle speed to the original vehicle speed in conjunction with the steering wheel operation returning to straight running, the spin turn is performed only by the steering wheel operation Operation can be slowed down to the appropriate vehicle speed, which can save troublesome traveling shifting operations.However, there is a problem in that work efficiency is reduced by deceleration when work that does not require spin turns, and traveling performance is reduced by deceleration when working in wet fields. Is reduced. Further, when the reduction ratio of the vehicle speed to the steering wheel operation amount is reduced, agile turning operation cannot be obtained on a road or in a dry field, and there is a problem that the turning performance (spin turn) performance particularly in dry field work is reduced.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a traveling speed change member for continuously changing the driving speed of the left / right traveling crawler by operating the traveling speed change lever, and a driving speed of the left / right traveling crawler by operating the steering handle. Turning decelerating means for decelerating a vehicle speed determined by an operation amount of a traveling shift lever in proportion to an operation amount of a steering handle, in a mobile agricultural machine having a steering member for continuously changing the difference between A turning non-deceleration means for shifting the vehicle speed only by operating the traveling shift lever irrespective of the handle is provided, and a deceleration and non-deceleration switching means for switching between these deceleration and non-deceleration means is provided. The speed of the vehicle is reduced according to the amount to turn the agile aircraft, while on wet or muddy surfaces, the vehicle speed is kept almost unchanged without reducing the speed of the vehicle. Performing the turning of the aircraft by-ring, and performs satisfactorily work easily switched to optimum turning characteristic even in the field to coexist such as dry paddy field or Shitsuden.

Further, by using a switching spool for the switching means,
By switching the deceleration and non-deceleration means by sliding switching operation of the switching spool, it is built in a compact body and easy to operate, and has optimal turning characteristics in any field such as dry fields or wet fields. The operation is performed by switching well.

Further, a pedal for switching the switching spool is provided, and the deceleration and non-deceleration means are switched by pressing the pedal, so that dry fields or wet fields are mixed and the frequency of the switching operation is extremely high. By arranging a pedal near the driver's seat or the like, it is possible to easily operate the vehicle even during a driving operation and to perform the operation with an optimum turning characteristic.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. Fig. 1 is an overall side view of the combine, Fig. 2
Is a plan view of the same, in which (1) is a track frame on which a pair of left and right traveling crawlers (2) are mounted, (3) is a machine frame installed on the track frame (1), and (4) is a feed chain. A threshing unit which stretches (5) to the left and incorporates a handling cylinder (6) and a processing cylinder (7), and (8) a cutting unit provided with a cutting blade (9) and a grain culm transport mechanism (10). , (11) are hydraulic cylinders for raising and lowering the cutting unit (8) via the cutting frame (12), (13) is a straw processing unit facing the end of the straw chain (14), and (15) is a threshing unit ( A grain tank that carries the grains from 4) through a frying cylinder (16), (1
7) a discharge auger for carrying out the grains of the tank (15) out of the machine, (18) a driver's cab provided with a round steering handle (19) and a driver's seat (20), and (21) a driver's seat (2
0) An engine provided below, configured to continuously cut and thresh grain culms.

Further, as shown in FIG. 3, a transmission case (22) for driving the traveling crawler (2) includes a pair of a first hydraulic pump (23) and a first hydraulic motor (24).
And a pair of a second hydraulic pump (26) and a second hydraulic motor (27) for forming a hydraulic continuously variable transmission mechanism for traveling main transmission. A steering member (28) forming a continuously variable transmission mechanism; and an input shaft (29a) (29b) of the first and second hydraulic pumps (23) (26) on an output shaft (21a) of the engine (21). )
Are connected by transmission belts (30a) (30b),
The hydraulic pumps (23) and (26) are configured to be driven.

An output shaft (31) of the first hydraulic motor (24) is provided with an auxiliary transmission mechanism (32) and a differential mechanism (3).
3) through the driving wheels (3) of the left and right traveling crawlers (2).
The differential mechanism (33) has a pair of left and right symmetric planetary gear mechanisms (35) and (35), and each planetary gear mechanism (35) has one sun gear (36).
, Three planetary gears (37) meshed on the outer periphery of the sun gear (36), and a ring gear (38) meshed with the planetary gears (37).

The planetary gear (37) is rotatably supported on a carrier (41) of a carrier shaft (40) coaxially with a sun gear shaft (39), and sandwiches the left and right sun gears (36) and (36). The left and right carriers (41) are arranged to face each other, and the ring gear (38) has internal teeth (38a) meshing with each planetary gear (37) and is arranged on the same axis as the sun gear shaft (39). The carrier shaft (4) is rotatably supported on the shaft (40).
0) is extended to form an axle to support the drive wheel (34).

In addition, a traveling hydraulic continuously variable transmission member (2)
5) The forward / reverse rotation of the first hydraulic motor (24) and the control of the number of rotations are performed by adjusting the angle change of the rotary swash plate of the first hydraulic pump (23), and the rotation of the first hydraulic motor (24) is performed. The output is transmitted from the transmission gear (42) of the output shaft (31) to each gear (4).
3) A center gear (46) fixed to the sun gear shaft (39) via (44) (45) and the auxiliary transmission mechanism (32).
To rotate the sun gear (36). The sub-transmission mechanism (32) includes a sub-transmission shaft (47) having the gear (44) and a parking brake shaft (49) having a gear (48) that meshes with a center gear (46) via the gear (45). ), And a pair of low-speed gears (50) (5) between the auxiliary transmission shaft (47) and the brake shaft (49).
1) Medium-speed gear (52) (53) High-speed gear (5
4) By providing (48), the low-medium-speed slider (55) and the high-speed slider (56) are slid to switch the sub-transmission between low speed, medium speed, and high speed. Note that there is neutrality between low and medium speeds and between medium and high speeds. In addition, a parking brake (57) is provided on the brake shaft (49), and a cutting PTO that transmits torque to the cutting unit (8).
The auxiliary transmission shaft (47) is connected to the shaft (58) via gears (59) and (60) and a one-way clutch (61), and the mowing unit (8) is driven at the vehicle speed synchronization speed.

As described above, the driving force from the first hydraulic motor (24) transmitted to the sun gear shaft (39) via the center gear (46) is applied to the left and right planetary gear mechanisms (35).
And to the left and right carrier shafts (40) via
The rotation transmitted to the left and right carrier shafts (40) is transmitted to the left and right drive wheels (34), respectively, to drive the left and right traveling crawlers (2).

Further, a steering member (28) formed by a hydraulic stepless speed change mechanism for turning is provided with a second hydraulic motor (27) by adjusting an angle of a rotary swash plate of a second hydraulic pump (26).
For controlling the forward / reverse rotation and the number of revolutions of the vehicle, including a brake shaft (63) having a steering output brake (62), a clutch shaft (65) having a steering output clutch (64), and the left and right ring gears. Left and right input gears (66) and (67) that are always engaged with the external teeth (38b) of (38) are provided, and the brake shaft (6) is mounted on the output shaft (68) of the second hydraulic motor (27).
3) The clutch shaft (65) is connected via the steering output clutch (64), the right input gear (67) is connected to the clutch shaft (65) via the forward gear (69), and the clutch shaft is The left input gear (66) is connected to (65) via a forward rotation gear (69) and a reverse rotation gear (70). The brake (62) is turned on by the neutralization of the sub-transmission sliders (55) and (56), and the clutch (6) is turned on.
4), the brake (62) is turned off and the clutch (64) is turned on at the time of the output of the sub-shift other than the neutral, and the forward gear (69) is applied to the external teeth (38b) of the right ring gear (38). ) Is transmitted to the external gear (38b) of the left ring gear (38) via the forward gear (69) and the reverse gear (70).
7) The rotation is transmitted, and when the second hydraulic motor (27) is rotated forward (reverse rotation), the left ring gear (38) is rotated reversely (forward rotation) and the right ring gear (38) is rotated forward (rotation) at the same left and right rotation speed. (Reverse rotation).

Thus, the second hydraulic motor for turning (27)
When the first hydraulic motor (24) for traveling is driven in a state where the left and right ring gears (38) are stopped and fixed, the rotation output from the first hydraulic motor (24) is The right and left traveling crawlers (2) are transmitted to the sun gear (36) at the same rotation speed, and are driven by the same rotation speed in the left and right same rotation direction via the planetary gear (37) and the carrier (41) of the left and right planetary gear mechanism (35). Then, the vehicle travels straight in the front-rear direction. On the other hand, when the first hydraulic motor (24) for traveling is stopped and the left and right sun gears (36) are stationary and fixed, the second hydraulic motor (27) for turning is driven forward and reverse to rotate the left planetary gear. The gear mechanism (35) rotates forward or backward, and the right planetary gear mechanism (35) rotates reversely or forward, driving the left and right traveling crawlers (2) in the reverse direction, and turning the body left or right. Further, by driving the second hydraulic motor for turning (27) while driving the first hydraulic motor for traveling (24), the body turns right and left and the course is corrected. The turning radius is determined by the output rotation speed of the second hydraulic motor (27).

Further, as shown in FIGS. 2, 4 to 13, a steering column (71) is erected on the front upper surface of the driver's cab (18) and fixed to the steering column (7).
1) A steering handle (19) is attached to the upper side of the upper surface so as to be rotatable around the vertical axis, a side column (72) is provided on the left side of the cab (18), and a transmission (22) is provided below the side column (72). The main transmission lever (73),
Sub transmission lever (74), reaping clutch lever (75),
Push the threshing clutch lever (76) to the side column (7
Attach to 2). In addition, the steering column (7
1) is formed by molding an aluminum alloy casting,
Multiple bolts (77) with a split structure that can be split left and right
To form a box shape.

Further, a tilt base (78) is integrally formed on the steering column (71), and the tilt base (78) is formed.
To the tilt bracket (8) via the fulcrum bolt (79).
0) is rotatably supported, and the tilt bracket (80) is fixed by the tilt lever (81) so that the angle can be freely adjusted. A shaft case (8) is attached to the tilt bracket (80).
2) A shaft case (82) is extended above an upper cover (83) for fixing the lower part integrally and fixed to the upper surface of the column (71), and the upper handle shaft (84) is rotatable inside the shaft case (82). The steering handle (19) is fixed at the upper end of the upper handle shaft (84), and the handle (19) is moved and adjusted around the fulcrum bolt (79) by operating the tilt lever (81) to a fixed position. And the handle (19) mounting position is adjusted in the front-rear direction to be fixed at a position where the operator can easily operate.

Also, the upper end of the lower handle shaft (86) is connected to the lower end of the upper handle shaft (84) via a universal joint (85), and the lower handle shaft (86) is mounted on the upper part of the steering column (71). In addition to being rotatably supported, the upper end of the steering input shaft (87) is rotatably supported above the steering column (71), and the gear (88) of the lower handle shaft (86) and the steering input shaft (87). ) Is engaged with each other to connect the shafts (86) and (87), and the steering input shaft (87) is extended vertically at substantially the center of the inside of the steering column (71).

Further, the steering column (71)
A bearing member (90) is detachably fixed to the left and right sides substantially in the middle of the vertical width, and one end of the transmission input shaft (91) is rotatably cantilevered to the bearing member (90) via the bearing (92). The transmission input shaft (91) is supported substantially horizontally in the left-right direction, and the lower end of the steering input shaft (87) is connected to the upper end of the input fulcrum shaft (94) via a universal joint (93). The steering input member (95) is fixed to the fulcrum shaft (94), the steering input member (95) is rotatably mounted on the speed change input shaft (91), and the input connector (95) is connected to the steering input member (95). 96) is detachably fixed, and the link bolt (9
7) connects the steering input member (95) to the input connector (96), and rotatably supports the steering input member (95) to the transmission input shaft (91) via a bearing (95a). Then, the steering input member (95) is moved to the steering input shaft (8).
7) Make it rotatably supported around. The steering input member (95) is rotated forward and reverse around a substantially vertical axis of the input shaft (87) by forward and reverse rotation of the steering input shaft (87).
The input fulcrum shaft (94) and the steering input member (95) are tilted in the front-rear direction around the center line of the substantially horizontal input shaft (91) by forward / reverse rotation of the speed change input shaft (91). The universal joint (93) is attached to the intersection of the center line of the steering input shaft (87) of the steering wheel and the center line of the speed change input shaft (91) in the horizontal direction at right angles, and the steering input shaft (87) of the steering handle (19). By the forward / reverse operation, the steering input member (95) and the input connector (96) are rotated forward / reverse around the center line of the steering input shaft (87).

Further, the steering column (71)
The main transmission shaft (99) is rotatably supported on the lower front side of the
The left end of the main transmission shaft (99), which extends substantially horizontally in the left-right direction, protrudes to the left outside of the steering column (71), and is rotatable on the machine base (3) below the side column (72). A link (101) is attached to the intermediate shaft (100).
(102) and the main transmission shaft (99) is connected via the rod (104) with the length adjustment turnbuckle (103). As shown in FIG. 4, a fulcrum plate (106) is rotatably mounted on the machine base (3) via a lever fulcrum shaft (105), and the main transmission lever is mounted on the fulcrum plate (106) via a cylinder shaft (107). (73) The base is mounted to be swingable in the left-right direction, and the links (108) (109) are connected to the fulcrum plate (106).
The main transmission shaft (99) is rotated forward and backward by a speed change operation of swinging the main transmission lever (73) forward and backward around the lever fulcrum shaft (105) by connecting the intermediate shaft (100) via the. Further, the main transmission shaft (99) is connected to the transmission input shaft (91) via the rod-type main transmission member (110), the upper connecting plate (111) and the lower link (112). The steering input member (95) is tilted back and forth around the center line of the transmission input shaft (91) by a forward / reverse operation of the main transmission shaft (99).

Further, a cylindrical steering output shaft (113) is rotatably mounted on the main transmission shaft (99), and the link steering output member (114) is fixed to the steering output shaft (113). At the same time, the upper end of the rod-shaped steering connection member (115) is connected to the input connector (96) via the universal joint-type steering input connection (116), and the ball-and-joint-type steering output connection ( The lower end of the steering connection member (115) is connected to the steering output member (114) via the steering connection member (117) to constitute a steering mechanism (118) for changing the traveling course.

Further, a speed change output shaft (119) is rotatably supported inside the steering column (71) substantially parallel to the steering output shaft (113) above the steering output shaft (113),
The link type shift output member (120) is connected to the shift output shaft (11).
9) and a rod-shaped speed change coupling member (12).
The upper end of 1) is connected to the input connector (96) via a universal joint type speed change input connection (122), and the speed change coupling member (12) is connected via a ball joint type speed change output connection (123).
The lower end of 1) is connected to a shift output member (120) to change the traveling speed and switch between forward and reverse.
4).

Furthermore, the inner steering operation shaft (125) and the outer speed change operation shaft (12) of the dual shaft structure rotatable with respect to each other.
6) is rotatably mounted on a bearing (127) in the center of the left and right widths at the lower rear side of the steering column (71).
The variable speed output shaft (11) is connected via a ball joint shaft (128) and a variable speed link (129) (130) whose length is adjustable.
9), the upper end of the speed change operation shaft (126) is connected, and the steering output shaft (11) is connected via a ball joint joint shaft (131) whose length can be adjusted and the steering links (132) and (133).
The upper end of the steering operation shaft (125) is connected to 3).

The operating shafts (125) and (126)
Are set up on the bottom of the steering column (71) substantially vertically on the same axis, and the upper ends of the operation shafts (125) and (126) are extended inside the steering column (71), and the output shafts (113) ( 119) and each operating shaft (125) (12) below the bottom of the steering column (71).
6) The operation shafts (125) (1) are provided on the lower surface side of the operator's cab (20) on the operator boarding step (134) by projecting the lower end.
26) The transmission member (2
5) The vehicle speed control arm (13) is connected to the output control shaft (135).
6) fixed, adjustable length vehicle speed rod (138) with turnbuckle (137) and vehicle speed link (139)
A vehicle speed control arm (136) is connected to the lower end portion of the speed change operation shaft (126) via a gear. The first hydraulic pump (23) adjusts the swash plate angle by the forward / reverse operation of the output control shaft (135). The rotation speed control and forward / reverse switching of the hydraulic motor (24) are performed to continuously change the traveling speed (vehicle speed) and to switch between forward and backward. Further, a steering control arm (141) is fixed to an output control shaft (140) of the steering member (28),
A steering control arm (141) is connected to the lower end of the steering operation shaft (125) through a length-adjustable swing rod (143) with a turnbuckle (142) and a swing link (144). ), The swash plate angle of the second hydraulic pump (26) is adjusted to control the rotation speed of the second hydraulic motor (27) and to switch between forward and reverse rotations. Switching between left and right turning directions is performed.

Further, the steering column (71)
An accelerator lever (145) is provided on the outer surface on the right side of the engine so as to be rotatable in the front-rear direction.
An accelerator wire (146) for connecting the engine (2) is extended from below along the inside of the front surface of the steering column (71), and the engine (2) is operated by an accelerator lever (145).
1) The number of revolutions is manually adjusted, a maintenance window (147) is opened on the rear surface of the steering column (71), and the maintenance window (147) is closed by a removable lid (148).

As is apparent from the above, the transmission mechanism (12
4) The steering mechanism (118) changes the steering amount in proportion to the operation amount. The steering amount is automatically enlarged by the high-speed running shift, and the steering amount is automatically reduced by the low-speed running shift. With a certain amount of operation of the steering handle (19), the turning radius of the left and right traveling crawlers (2) is maintained substantially constant irrespective of the traveling speed, thereby changing the traveling speed of the agricultural work and making the aircraft follow the crop line. In addition to making corrections, a reverse conical transmission mechanism (124) and a steering mechanism (118) are formed, and the steering input shaft (87) is rotated by the steering operation to connect the steering input member (95). For example, an operation of reducing the traveling speed while turning is performed, and a speed change input shaft (91) is rotated by a speed change operation to operate a steering input member (95), thereby enlarging or reducing the turning radius due to the running speed change. Few rows To perform operations such as discontinuation of turning output by the running gear neutral.

Further, a steering input connecting portion (116) for connecting the steering input member (95) and the steering connecting member (115) is disposed on the center line of the transmission input shaft (91), and the transmission input member (96) is provided. ) And the speed change coupling member (121) are arranged on a straight line (A) intersecting the core of the speed change input shaft (91), and the steering input shaft (87) and the speed change input are arranged. Steering input member (95) about axis (91)
The relative motion of the gears can be easily set, the design and assembly and structure can be simplified, the operation reliability can be improved, and the axis of the transmission input shaft (91) and the axis of the steering input shaft (87) intersect. The speed change input connecting portion (122) and the steering input connecting portion (116) are arranged on the circumference (C) centered on the center intersection (B), and the structure of the steering input member (95) and the like is simplified. A speed change output connecting portion (123) for connecting the speed change output member (120) and the speed change coupling member (121), and a steering output member (11).
A steering output connecting portion (117) for connecting the steering coupling member (115) with the steering output coupling member (115) is disposed on the core wire of the steering input shaft (87) to perform reverse handle development by shifting between forward and reverse. The shift output member (120) and the steering output member (1)
14) Design, assembly and structure are simplified, operation reliability is improved, etc., and the transmission output connecting portion (123) is connected to the axis (B) of the transmission input shaft (91) and the steering input shaft (87). ) Is different from the distance of the steering output connecting portion (117), and the transmission output connecting portion (123) and the steering output connecting portion (117) are separated from each other on the same straight line (D). (117) The interference prevention and the setting of the movement range of (123) can be easily performed, and the speed change coupling member (12
1) and the steering connection member (115) are configured to be installed in a small place.

Further, the speed change input connecting portion (116) and the steering input connecting portion (122) are formed by a circle centered on the intersection (B) between the speed change input shaft (91) and the steering input shaft (87). Zhou (C)
The traveling speed change is performed by keeping the steering input connection (116) at a constant position by rotating the speed change input shaft (91) and maximizing the displacement of the speed change input connection (122). And each of the input connection sections (116)
The structure in which the speed change input shaft (91) is arranged on the plane on which the (122) is moved easily ensures the amount of movement of each connecting portion (116) (122), and is compact and functionally the steering input member (95). The shift input connecting portion (122) and the steering input connecting portion (116) are moved within a range of about 90 degrees around the steering input shaft (87), and the reverse steering development by forward / reverse switching is performed. Prevention and each input connection (116)
In addition to securing the movement amount of (122), the steering input shaft (87)
Transmission input connecting portion (12
2) In the decelerating direction, the operation is easily performed, and the spin turn operation for changing the direction around the traveling crawler (2) inside the turning is easily performed, and the device is functionally configured with a compact structure. Further, the spin turn operation is performed by the steering member (2).
8) An operation of rotating one of the left and right traveling crawlers (2) in the forward direction and the other in the reverse direction via the differential mechanism (33) by the output of the differential mechanism (33), thereby turning the left and right traveling crawlers (2) forward and backward and around the left and right center points. The forward and backward traveling and turning are performed simultaneously, and the turning radius is determined by the ratio of the rotation of the transmission member (25), which is the forward and backward output, and the rotation of the steering member (28), which is the turning output. Further, a transmission output shaft (119) and a steering output shaft (113) are provided substantially parallel to the transmission input shaft (91), and the output shafts (113) and (119) form a case that can be divided into a plurality of columns. (71) and the transmission input shaft (91) and the output shafts (113) and (119) are extended in the left-right direction, so that the connecting structure in the longitudinal direction of the fuselage can be easily obtained. The connection between the main transmission lever (73) and the transmission input shaft (91), the transmission member (25) and the steering member (28) and the output shaft (11).
3) It is configured so that the connection with (119) can be easily performed, and the operation structure can be simplified and the handling property can be improved.

Further, as shown in FIG. 14, a phase adjusting slot (149) through which the connecting bolt (97) is loosely inserted is opened in the input connector (96), and the core of the steering input shaft (87) is connected to the input connector (96). The slot (14) is placed on the same circumference as the center.
9) is formed, and the steering input member (9) is fixed in a state in which the shift input shaft (91) is fixed to the traveling shift neutral position by engagement of the bolt-shaped reference setting member (98) and the neutral setting hole (150).
5) is rotated only right and left with respect to the speed change input shaft (91) to correct the relative position of the steering input member (95), and the turning neutral determined by the operation of the steering handle (19). Set a neutral position and running speed. Further, a reference setting member (98) for fixing the shift input shaft (91) at the reference position is provided so as to be freely detachable, the bolted body (98a) shown in FIG. 14 is removed, and the reference setting member (98) as shown in FIG. ) The tip is engaged with the neutral setting hole (150), and the neutral position of the traveling speed change and the steering straight-forward position are set to the neutral setting hole (15).
0) and the reference setting member (98), the joint nut (121a) (1) shown in FIGS.
By the screw-in / out operation of 15a), the speed change coupling member (121)
Alternatively, an adjustment at the time of assembling such that the connecting length of the steering coupling member (115) or the like is expanded or contracted is performed to improve the assembling workability.

Further, as shown in FIGS. 16 to 18, the gear (88) has a plurality of teeth (1) in an outer peripheral range of 270 degrees.
51) is formed, an outer peripheral range of 90 degrees is formed in an arc (152), the total rotation angle of the steering handle (19) is set to 270 degrees, and the angle of left steering rotation or right steering rotation is set to 135 degrees. The steering wheel (19) is set so that the operator can easily perform the rotation operation with one hand. Further, the sector gear (89) has a plurality of teeth (153) in an outer peripheral range of 130 degrees.
Is formed on the circular cam (154), and the teeth (151) of the gear (88) and the teeth (153) of the sector gear (89) are engaged with each other to form the gears (88) (8).
At the time of the maximum forward / reverse rotation of 9), the stoppers (155) at both ends of the arc (152) and the stoppers (156) at both ends of the arc cam (154) are brought into contact with each other to regulate the rotation of the steering handle (19). The steering input member (95) and the input connector (96) are rotated forward or backward in the range of 65 degrees around the center line of the steering input shaft (87), so that the steering input member (95) is rotated and moved on a plane. The speed change input shaft (91) and the main speed change member (1
10) A structure in which a space for arranging the upper end portion is secured, and the steering input connecting portion (116) is provided on the core line of the transmission input shaft (91), and the input connecting portions (116) on the same circumference.
(122) can be easily obtained at a 90-degree distance, and the structure can be made compact, and the design and assembly can be simplified.

Further, a straight notch (157) is formed at the center of the arc cam (154) of the sector gear (89), and a detent shaft (158) is rotatably supported on the upper wall of the steering column (71). Detent axis (15
8) A detent arm (159) is fixed to the lower end, a detent roller (161) is rotatably supported on the detent arm (159) via a roller shaft (160), and the detent roller (161) is attached to the arc cam (154). The detent roller (161) is removably engaged with the straight notch (157), and the steering handle (19) is supported at the straight position. Further, a detent lever (162) is fixed to the upper end side of the detent shaft (158), and one end of a neutral spring (163) wound around the detent shaft (158) is locked to the detent lever (162), and the steering column (162) is fixed. The other end of the neutral spring (163) is brought into contact with the receiving plate (164) of (71), and the detent roller (161) is attached to the circular cam (154) and the linear notch (157) by the neutral spring (1).
63). Further, a microswitch-type straight-ahead sensor (165) for electrically detecting the straight-ahead position of the steering handle (19) by switching on and off is attached to the detent lever (162).

Further, as shown in FIGS. 12 and 13, a telescopic damper (166) is provided at an intermediate portion of the pivot rod (143), and a spring case (167) fixed to one rod (143) end is provided. Spring seats (168) and (169) that are slidably locked to the other rod (143) end.
And a compression spring (170) that is wound around the rod (143) in a compressed state via spring seats (168) and (169) in the damper (166), and is provided by a steering operation of a steering handle (19). When a certain pushing force is applied to the rod (143) in both the pushing direction and the pulling direction,
When the steering control arm (141) is moved to the maximum output position by operating the steering angle (116%) (85%) of the steering handle (19), the spring (170) compresses to expand and contract the rod (143). Then, the steering handle (19) is further rotated in the turning direction while the second hydraulic pump (26) is maintained at the maximum output, and the steering handle (19) is operated from the turning angle of 116 degrees to the turning angle of 135 degrees. It is composed.

Further, as shown in FIGS. 12, 19 and 20, a pin (171) is fixed to the vehicle speed control arm (136), and a slot (172) through which the pin (171) is slidably inserted. ) Is formed at the end of the vehicle speed rod (138), and the vehicle speed rod (138) is connected to the vehicle speed control arm (136).
To the vehicle through a slot (172) and a pin (171), and to a control shaft (13) of a vehicle speed control arm (136).
A detent cam (173) is fixed coaxially with 5), a detent roller (174) is elastically pressed against the cam (173) by a spring (175), and a vehicle speed control arm (136) is formed by the cam (173) and the roller (174). ) Is automatically returned to the neutral position, the first hydraulic motor (24) is stopped and maintained by the neutral support of the arm (136),
And the arm (136) is neutral and the main shift lever (7
When the 3) is in the neutral operation position, the pin (171) is located substantially at the center of the long hole (172) in the longitudinal direction, and the stroke substantially equal to both forward and backward shifts by pushing and pulling the rod (138) is achieved. (171), and the arm (136) is configured to perform a substantially symmetric (forward / reverse) operation in both forward and backward shifts.

Then, as shown in FIG. 20, the main shift lever (73) at the neutral position (O) is shifted to move the dead zone (P) to the shift start position (Q). The pin (171) comes into contact with the longitudinal end of the long hole (172) by pushing and pulling the vehicle speed rod (138), and the main speed change lever (73) and the vehicle speed control arm (136)
And the main transmission lever (73) is further shifted to move the shift zone (R) to shift the transmission member (2).
5) The vehicle speed control arm (136) in the neutral position (T) by tilting and supporting it up to the maximum output position (S).
Is moved to the shift zone (R) up to the maximum output position (S) in proportion to the amount of operation of the main shift lever (73), and the first hydraulic motor (24) of the shift member (25) is steplessly output. The left and right traveling crawlers (2) are driven at the same speed in the same direction to move forward and backward.

Further, as shown in FIGS. 14, 21, and 22, a notch (176) is provided in the bearing portion (90) to form a concave portion (177), and the steering handle (19) is turned to the maximum left turning position. When the angle (135 degrees) is operated, the shift input connecting portion (1
22) and the speed change coupling member (121) with the concave portion (17).
7), and the connecting portion (122) is inserted into the bearing portion (9).
As compared with the structure that abuts the steering wheel (19), the maximum vehicle speed deceleration rate when the steering wheel (19) is turned left and right is made larger. A constant speed zone (V) is formed before the bolt (97) comes into contact with the edge of the phase adjustment hole (149), and the center speed of the body is reduced by a steering operation of the steering handle (19) within a turning angle of 15 degrees. Correct the course while keeping it approximately constant. Further, the steering handle (19) is further steered to move the turning zone (W) to move the steering handle (19) to the maximum output position (X) of the steering member (28) for a turning angle of 116 degrees. To move the steering control arm (141) up to the maximum output position (X) in proportion to the rotation angle of the steering handle (19), and the second hydraulic motor of the steering member (28). (27) steplessly outputs a speed change to change the speed difference between the left and right traveling crawlers (2) steplessly, and sets the vehicle speed rod (1) in proportion to the rotation angle of the steering handle (19).
38) and the vehicle speed control arm (136) are moved back in the neutral direction of shifting, the traveling speed of the left and right traveling crawlers (2) is steplessly reduced, and the turning angle is increased by increasing the steering angle of the steering handle (19). Becomes smaller, the traveling speed becomes slower, and a left-right turning operation is performed. Further, the steering wheel (19) having a turning angle of 116 degrees is further steered to rotate the inside of the spin turn zone (Y) to the maximum steering position (Z) having a turning angle of 135 degrees, thereby providing a damper. Swivel rod (143) by the expansion and contraction absorption operation of (166) (connection length)
While the steering control arm (141) is maintained at the maximum output position (X), the vehicle speed rod (138) and the vehicle speed control arm (136) are further moved back in the neutral direction of the speed change, and the left and right traveling crawlers ( It is configured to perform a spin-turn operation of turning around a turning center formed in the middle of the left and right widths of 2).

As shown in FIGS. 19, 20 and 22,
The vehicle speed rod (138) and the vehicle speed control arm (136) are connected by a long hole (172), and the main speed change lever (73) is connected.
Is formed larger than the actual speed change stroke, and a concave portion (177) is formed in the bearing (90) provided in the left turning direction of the speed change input connecting portion (122) to form the connecting portion (122). ) Into and out of the recess (177) to set the vehicle speed reduction rate to 25% at the maximum steering angle (135 degrees) of the steering handle (19) at the time of the maximum output operation of the main transmission lever (73). While the deceleration rate was reduced to 40%, the deceleration rate was further increased and decelerated to 25%, a spin-turn operation was performed, and the aircraft was turned around 180 degrees at the field headland, and the next uncut kernel It is configured to move to the culm cutting process. As shown in FIG. 22, the main shift lever (7
3) At the maximum output, when the damper (166) operates at the steering angle (116) of the steering handle (19) to maintain the maximum output of the steering member (28), the steering angle (116) of the steering handle (19) is maintained.
The deceleration rate of the left and right traveling crawlers (2) is maintained substantially equal in the range of degrees to 135 degrees, and the speed difference between the left and right traveling crawlers (2) becomes maximum at the position of the turning angle of the steering handle (19) of 116 degrees. The speed difference between the left and right traveling crawlers (2) is maintained substantially constant in the range of the steering angle of the steering handle (19) from 116 degrees to 135 degrees, and the traveling speed is reduced in proportion to the steering angle of the handle (19). You.

Further, the amount of deceleration of the vehicle speed control arm (136) by the steering handle (19) is increased to form a large deceleration rate, so that the deceleration rate required for the spin turn operation can be easily obtained. The vehicle speed control arm (136) and the vehicle speed rod (13)
8) is connected to the long hole (172) by the pin (171), and the amount of operation of the vehicle speed rod (138) or the amount of deceleration of the vehicle speed control arm (136) depends on the size of the long hole (172) and the pin (171). And the like, the output characteristics of the speed change member (25) and the steering member (28), the deceleration control operation of the steering handle (19), etc. can be easily considered, and the mounting structure of the vehicle speed rod (138) can be simplified. It is designed to improve handling, such as integration and assembly work, and to reduce manufacturing costs.

Further, the input member (95) is operated by operating the dead zone (P) of the main shift lever (73).
(96) is shifted from the neutral position (P) to the shift start position (Q) around the shift input shaft (91), and the steering handle (1) is shifted.
9) In the constant speed zone (V) centered on the straight traveling position, the operating ratio of the steering control arm (141) to the steering angle of the steering wheel (19) is increased, and the main shift lever (73) is shifted to the shift zone (R). When the vehicle is moved at a very low speed, the operation amount of the steering control arm (141) is increased by operating the steering handle (19) in the constant speed zone (V), and the steering amount of the steering member (28) is increased. 2 Handle the rotation change rate of the hydraulic pump (26) with the handle (19)
The turning operation time at the very low speed output of the second hydraulic pump (26) is reduced by increasing the turning angle, and the motor (2
7) Prevents the turning operation from being performed in the low-speed output range, and sets the main shift lever (73) to the steering handle (1) in the low-speed running state.
The turning operation according to 9) is performed by increasing the output of the second hydraulic pump (26) by a certain amount or more. As described above, by preventing the turning operation of the second hydraulic pump (26) at the low-speed rotation output, even if the second hydraulic pump (26) has low efficiency in the low-speed output range, the second hydraulic pump (26) , The turning operation can be performed while securing a certain output or more. Further, after the control of the steering member (28) by the steering handle (19) is started by securing the turning force of a certain level or more by the shifting operation of the main shift lever (73), the traveling shift operation is performed. Is started later, it is possible to prevent a shortage of the turning force of the steering member (28) during the low-speed movement, and the steering member (2)
8) to reduce the manufacturing cost and to improve the turning performance of the left and right traveling crawlers (2). By operating the main shift lever (73), the steering and shift input members (about the center line of the shift input shaft (91) are changed). After rotating the input members (95) and (96) by a fixed angle, the input members (95) and (96) are
5), the transmission member (25) is operated, and the input members (95) and (96) are moved to a steering operation state by a shift operation, and then output from the transmission member (25) to output the traveling crawler (25). Since 2) is driven, even when the vehicle travels at a low speed with a small running output, the necessary amount of turning force is secured by increasing the control amount of the steering member (28) by the steering operation of the steering handle (19), and the vehicle moves at a low speed. It is configured to improve the turning performance at the time.

When the main shift lever (73) is in the neutral position, the forward (reverse) operation of the steering handle (19) causes the input members (9) to rotate around the center line of the steering input shaft (87).
5) (96) and the coupling members (115) (121) move on a conical trajectory, and the output members (114) (12)
0) and the state in which the output shafts (113) and (119) are stopped. Further, the forward (reverse) operation of tilting the main transmission lever (73) forward (rearward) causes the input members (95) and (96) to tilt forward (rearward) around the center line of the transmission input shaft (91), and to operate. While maintaining the state where the direction input connecting portion (116) is stopped at a fixed position, the speed change input connecting portion (12
2) is moved upward (downward) and the transmission output member (12
0) Upward (downward) swing of the transmission output shaft (119)
Of the first hydraulic motor (2) by switching the swash plate angle of the first hydraulic pump (23) of the transmission member (23).
4) is rotated forward (reverse), and the left and right traveling crawlers (2) are driven forward (reverse) by forward (reverse) rotation of the output shaft (31) of the first hydraulic motor (24). Further, the rotation speed of the output shaft (31) changes in proportion to the tilt angle of the main transmission lever (73), and the forward (reverse) speed of the traveling crawler (2) is continuously changed.

Further, when the main shift lever (73) is tilted forward (rearward) to perform forward (reverse) operation,
By rotating the steering handle (19) leftward (rightward), the steering input member (95) is tilted forward (rearward) around the center line of the transmission input shaft (91). 87) Forward rotation (reverse rotation) around the core line, the steering input connecting portion (116) moves downward (upward), and the steering output member (1
14), the steering output shaft (11
3) is rotated forward (reverse rotation), the second hydraulic motor (27) is rotated forward (reverse rotation) by switching the swash plate angle of the second hydraulic pump (26) of the steering member (28), and the second hydraulic motor ( 27)
Forward (reverse) rotation of the output shaft (68), the left traveling crawler (2) is decelerated (increased), and the right traveling crawler (2) is accelerated (decelerated) to the left (right). Turn the aircraft and correct the course to the left (right). Also,
Simultaneously with the course correction operation, by turning the steering handle (19) to the left (rightward), the shift input member (96) is steered forward (rearward) around the center line of the shift input shaft (91). The input shaft (87) rotates forward (reverse) around the center line, the shift input connecting portion (122) moves downward (upward), and the shift output member (120) swings down (upward) to output the shift output shaft ( 119) is rotated in the reverse direction (forward rotation), and the speed change member (25) is rotated.
Is returned to the neutral direction to reduce the rotation speed of the output shaft (31) and reduce the traveling speed (vehicle speed). As described above, by the left and right steering operation of the steering handle (19) during the traveling movement, in proportion to the rotation angle of the steering handle (19),
The turning radius (angle) for correcting the course and the deceleration amount of the traveling speed change, and when the steering wheel (19) is rotated greatly, the speed difference between the left and right traveling crawlers (2) is increased to reduce the turning radius. At the same time, the amount of deceleration of the traveling speed increases and the vehicle speed decreases, and at the time of forward movement and reverse movement, the movement of the turning input connecting portion (116) is reversed with respect to the rotation of the steering handle (19), In either case, the turning operation direction of the steering handle (19) and the turning direction of the fuselage are made to coincide with each other, and the turning operation of the circular steering handle (19) for turning operation is performed by, for example, a tractor or a rice transplanter. It performs course correction and direction change with the same driving feeling as a wheeled vehicle.

FIG. 22 shows the relationship between the turning angle of the steering handle (19) and the speed of the left and right traveling crawlers (2) when the body turns right and left, and the turning angle of the handle (19) becomes large. The difference between the speeds of the left and right traveling crawlers (2) becomes larger, and the body center speed, which is the average speed of the left and right traveling crawlers (2), also depends on the traveling speed (high speed / standard speed / low speed) of the auxiliary transmission lever (74). Slow down. Move the steering handle (19) in the straight-ahead position to the left (right) about 15
In the reaping course correction range in which the gears are rotated by degrees, the speed change input connecting portion (122) moves in a substantially tangential direction with respect to the rotation of the steering input member (95), and the speed change output member (120) is maintained at substantially the same position as the straight running. And the second of the steering member (28)
Leftward (rightward) by steering output that causes the second hydraulic motor (27) to rotate forward (reverse) by the hydraulic pump (26)
Turn to adjust the course to match the curvature of the uncut culm (crop) row. At this time, the traveling crawler inside the turn (2)
Is substantially equal to the speed increase amount of the traveling crawler (2) on the outside of the turn, and the center speed of the body is maintained at substantially the same speed as the straight traveling. Also, the steering handle (19) is moved 15 degrees from the straight traveling position.
When the gear is rotated by more than degrees, the speed change coupling member (121) is pushed and pulled by the rotation of the steering input member (95), and the speed change output member (120) is decelerated in both left and right turns. The traveling speed output of the hydraulic pump (23) and the motor (24) is reduced, and the left and right traveling crawlers (2) (2)
Are driven in the same direction to advance (or reverse),
The left and right traveling crawlers (2) perform a brake turn operation to turn leftward (rightward) due to a traveling speed difference between the two (2),
Make a course correction to return to the original row or move to the next row when it comes off the uncut culm (crop) row. Further, when the steering handle (19) is rotated about 116 degrees, the damper (1) is rotated.
66) is operated to maintain the maximum swing output, and 135
The center speed of the aircraft is reduced to about one-fourth of the straight traveling speed in the range of the turning angle in degrees, the traveling crawler (2) inside the turning is driven in reverse, and the aircraft moves around the turning center between the left and right traveling crawlers (2). A rotating spin turn operation is performed, and the aircraft is shifted 180 degrees in the turning direction by the left and right widths of the left and right traveling crawlers (2).
The steering wheel (19) is rotated in the range of 0 to 135 degrees to perform a left or right turning operation, and 15 degrees to the left and right around the straight traveling position. Of the handle (19) in the range of rotation, along the row of uncut culms (crops), while correcting the alignment path while maintaining the traveling speed at the time of straight traveling, and changing the handle (19) from left to right to 116 to 135 degrees. ) While rotating the turning member (28) at the maximum output, the spin-turn operation of changing the direction of the airframe on the field headland and moving to the next work step is performed at a traveling speed of about one-fourth of that when traveling straight ( The deceleration is automatically reduced to 25%).

Further, as shown in FIGS. 11 and 23 to 26, a cylindrical reduction output shaft (178) and a direct connection output shaft (179) are rotatably supported on the transmission output shaft (119) to reduce the speed. The transmission output member (120) is fixed to the output shaft (178), the transmission link (129) is fixed to one end of the transmission output shaft (119), and the main transmission shaft (9) is fixed.
9) to the input link (18) directly connected via the boss (181).
2) is fixed, the direct output link (183) is fixed to the direct output shaft (179), and the roller (185) provided on the shaft (184) of the input link (182) is provided with a long hole (185) of the output link (183). 186) so as to be freely slidable into the main transmission shaft (99) via the links (182) and (183).
The output shaft (179) is directly connected to each shaft (99) (1).
79) is rotated interlockingly.

Further, a switching spool (187) is inserted into the hollow of the transmission output shaft (119) so as to be able to move in and out, and a clutch pin (188) to be engaged with the transmission output shaft (119) is inserted into the spool (187) insertion end. And a notch (189) (190) for engaging and disengaging the clutch pin (188) is formed on the deceleration output shaft (178) and the direct output shaft (179), respectively.
The deceleration output shaft (178) via the clutch pin (188) and the notches (189) (190) by the access operation of 7).
Alternatively, one of the direct connection output shafts (179) is alternatively connected to the transmission output shaft (119).

A compression spring (191) is interposed between the insertion end of the spool (187) and the transmission output shaft (119), so that the clutch pin (188) is normally notched (18).
9), the one end of the clutch operating spring (192) is engaged and connected to the protruding end of the spool (187), and the steering column (71) is attached to the left outer bearing base (193) in the front-rear direction. A longitudinal rotation shaft (194) is rotatably supported, and the other end of the spring (192) is detachably fixed to a middle portion of the rotation shaft (194) via a bolt (195). Then, a pedal plate (196) for fixing the rear end of the rotation shaft (194) is attached to the steering column (7).
The switch pedal (1) is protruded to the right outside of the column (71) along the back surface of the switch plate (1).
When the switching pedal (197) is pushed in, the clutch pin (188) is moved to the deceleration side notch (18) via the rotation shaft (194) and the operation spring (192).
9) It is configured to switch to the notch (190) on the more directly connected side to engage and hold. The relation between the compression spring (191) and the operation spring (192) is such that when the pedal (197) is in the free state, the pressing force of the compression spring (191)> the pressing force of the operation spring (192), and the pressing of the pedal (197). At the time of operation, the pressing force of the compression spring (191) <the operation spring (19)
2) to maintain the relationship of the pressing force. A lock plate (198) is provided on the right outer side of the steering column (71) to be engaged with the tip of the pedal (197) when the switching pedal (197) is pushed down and moved down, so that the entire field can be super-sized. In the case of wet fields, the switching pedal (19
7) The position is held by the lock plate (198) in a state where it is pushed in to improve workability.

As is clear from the above, the shift operation output from the main shift lever (73) is divided into two by the main shift shaft (99), and one output is set as a vehicle speed reduction output according to the angle of the steering wheel (19). The output member (120) is transmitted to the transmission link (129) via the deceleration output shaft (178) on the transmission output shaft (119), and the other output is output to the output link (1).
83) to the direct output shaft (17) on the transmission output shaft (119).
9) through a transmission link (129) to select the two transmission outputs on the transmission output shaft (119) and control the transmission of the first hydraulic pump (23) by one of the two transmission outputs. A traveling speed change member (25) for continuously changing the drive speed of the left / right traveling crawler (2) by operating a main transmission lever (73) as a speed change lever, and a left / right traveling crawler (2) by operating a steering handle (19). ), The vehicle speed determined by the operation amount of the main shift lever (73) is changed by the operation amount of the steering handle (19). Directly connected to a deceleration output shaft (178), which is a turning deceleration means for decelerating in proportion to the steering speed, and a turning non-deceleration means for changing the vehicle speed only by operating the main shift lever (73) regardless of the steering handle (19). output (179) and provided with a switching spool (18 a deceleration and non-reduction switching means switching to these deceleration and directly connected the output shaft (178) (179)
By providing 7), on a road or a dry field, the vehicle speed is reduced according to the steering operation amount and the agile aircraft turns, while on a wet field or a mud surface, the vehicle speed is substantially maintained without being reduced. By turning the body with a smooth turning feeling, even in a mixed field such as a dry field or a wet field, it is possible to easily switch to an optimum turning characteristic and perform a good operation.

The switching means is provided with a switching spool (187).
The output of the deceleration output shaft (178) and the output of the direct-coupled output shaft (179) are switched by the sliding switching operation of the switching spool (187), thereby reducing the complexity of the structure such as changing the control structure. It has a structure that is compactly incorporated in the body and easy to operate, and easily switches to an optimum turning characteristic in any field such as a dry field or a wet field to perform a good operation.

Further, a pedal (197) for switching the switching spool (187) is provided, and the output of the deceleration output shaft (178) and the output of the direct connection output shaft (179) are switched by pushing the pedal (197). Even in a field condition where a lot of dry fields or wet fields are mixed and the frequency of the switching operation is extremely high, the pedal (197) is disposed near the driver's seat (20), and the pedal is easily operated during the driving operation.
Work is performed well with optimal turning characteristics.

Further, since the mode is switched to the turning deceleration mode only by releasing the foot from the pedal (197), the operability on the road or in a dry field can be improved, and the turning (non-deceleration) by pushing the pedal (197) is performed. When the mode is switched, the spool (187) and the pin (188) are caused by an abnormal stepping force of the foot because the spring (191) (192) is used.
-It is possible to prevent the switching members such as the output shafts (178) and (179) from being adversely affected and to prevent such damages.

[0047]

As is apparent from the above embodiments, the present invention relates to a traveling speed change member (25) for continuously changing the drive speed of the left and right traveling crawlers (2) by operating the traveling speed change lever (73). In a mobile agricultural machine having a steering member (28) for changing the drive speed difference between the left and right traveling crawlers (2) steplessly by operating the direction handle (19), it is determined by the operation amount of the traveling speed change lever (73). Turning deceleration means (178) for decelerating the vehicle speed in proportion to the amount of operation of the steering handle (19), and shifting the vehicle speed only by operating the traveling shift lever (25) irrespective of the steering handle (19). A turning non-deceleration means (179) and a deceleration / non-deceleration switching means (187) for switching the deceleration / non-deceleration means (178) (179) are provided. While the speed of the vehicle is reduced according to the amount of steering operation, the agile aircraft turns while the vehicle speed is kept almost unchanged without reducing the vehicle speed on wetlands or muddy surfaces. go,
Even in a mixed field such as a dry field or a wet field, the work can be satisfactorily performed by easily switching to the optimum turning characteristics.

The switching means is provided with a switching spool (187).
, The deceleration and non-deceleration means (178) (179) are switched by sliding switching operation of the switching spool (187), so that it is compactly incorporated in the body and easy to operate. Thus, in any field such as a dry field or a wet field, it is possible to satisfactorily switch to the optimum turning characteristic and perform the operation.

Further, a pedal (197) for switching the switching spool (187) is provided, and the deceleration and non-deceleration means (178) (179) are operated by pushing the pedal (197).
Therefore, the pedal (197) is disposed near the driver's seat (20) even in a field condition where there are many dry fields or wet fields and the frequency of the switching operation is extremely high. Can also be easily operated and work can be performed satisfactorily with optimum turning characteristics.

[Brief description of the drawings]

FIG. 1 is an overall side view of a combine.

FIG. 2 is an overall plan view of the combine.

FIG. 3 is an explanatory diagram of a mission drive system.

FIG. 4 is an explanatory perspective view of a traveling speed change and steering operation unit.

FIG. 5 is an operation explanatory view of the same part.

FIG. 6 is a side view of the steering column.

FIG. 7 is an enlarged side view of the upper part.

FIG. 8 is an enlarged side view of the lower part.

FIG. 9 is a front view of a steering column.

FIG. 10 is an enlarged front view of the same.

FIG. 11 is an enlarged front view of the lower part.

FIG. 12 is an explanatory plan view of FIG. 4;

FIG. 13 is an enlarged view of FIG.

FIG. 14 is a cross-sectional view of a steering column.

FIG. 15 is a diagram illustrating a setting operation.

FIG. 16 is a partial plan view of the upper part of the steering column.

FIG. 17 is a partial view of the same.

FIG. 18 is an operation explanatory view of FIG. 16;

FIG. 19 is an explanatory diagram of the operation of the speed change member.

FIG. 20 is an explanatory diagram of a main speed change operation.

FIG. 21 is an explanatory diagram of a steering operation.

FIG. 22 is a diagram showing main shifting and steering handle operation.

FIG. 23 is an explanatory front view of a traveling speed change output switching unit.

FIG. 24 is an explanatory front view of a pedal unit.

FIG. 25 is an explanatory side view of the pedal section.

FIG. 26 is an explanatory diagram of a traveling speed change output switching unit.

[Explanation of symbols]

 (2) Traveling crawler (19) Steering handle (25) Transmission member (28) Steering member (73) Transmission lever (178) Deceleration output shaft (slewing deceleration means) (179) Directly coupled output shaft (slewing non-deceleration means) (187) Switching spool (197) Pedal

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (3)

[Claims] 1. A traveling speed change member for continuously changing the driving speed of the left and right traveling crawlers by operating a traveling speed change lever, and a steering for continuously changing the difference in driving speed of the left and right traveling crawlers by operating a steering wheel. Turning deceleration means for reducing the vehicle speed determined by the operation amount of the travel shift lever in proportion to the operation amount of the steering handle, and only the operation of the travel shift lever irrespective of the steering handle. And a deceleration / non-deceleration switching means for switching between the deceleration and non-deceleration means. 2. The mobile agricultural machine according to claim 1, wherein a switching spool is used as the switching means, and the deceleration and non-deceleration means are switched by sliding switching operation of the switching spool. 3. A mobile agricultural machine according to claim 2, wherein a pedal for switching the switching spool is provided, and the deceleration and non-deceleration means are switched by pressing the pedal.