JP2002096753A - Running transmission device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a comparatively compact running transmission device for a work vehicle capable of turning its machine body by gentle turn, brake turn, and pivotal turn while selecting turn mode by simple operation. SOLUTION: When running drive gears 30a, 30b are connected with a direct advance transmission gear 9 by a steering clutch mechanism 20, running devices 34a, 34b are driven by the direct advance transmission gear 9. When the running drive gears 30a, 30b are connected with turn gears 19a, 19b by the steering clutch mechanism 20, the running devices 34a, 34b are driven by the turn gears 19a, 19b and are braked by a turn brake 12 attached to an intermediate transmission shaft 13. The turn brake 12 is a meshing type brake and is energized on an in side by a brake spring. By operating a mode selection lever 70 along a linear operation path, brake turn mode, pivotal turn mode, and gentle turn mode are selectively realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straight-on engagement state in which a left traveling drive gear for driving a left traveling device is interlocked with a straight-ahead transmission gear, and a turning on-state in which a left traveling drive gear is interlocked with a left-turn gear. The right-hand drive gear for driving the right-hand drive is linked to the straight-ahead drive gear, and the right-hand drive gear is linked to the right-turn gear. A right-hand steering clutch mechanism that can be switched between the left and right states is provided.The rotating power of the drive shaft is transmitted in reverse by the intermediate transmission shaft to rotate the left turning gear and the right turning gear in the rotation direction opposite to that of the straight transmission gear. A reverse rotation transmission state in which the left rotation gear and the right rotation gear are rotated at a lower speed than the linear transmission gear in the same rotational direction as the linear transmission gear by transmitting the rotational power of the drive shaft at a reduced speed. Transmission state and front From the drive shaft about the traveling transmission apparatus for a work vehicle that is provided with a freely pivoting transmission mechanism switchable between disengaged condition abstinence the transmission to the left turning gear and right turning gear.

[0002]

2. Description of the Related Art In the above-mentioned work vehicle, a turning transmission mechanism is switched to a low-speed transmission state, and one of a left steering clutch mechanism and a right steering clutch mechanism is switched to a straight driving engagement state, and the other is switched to a turning engagement state. As a result, one of the left and right traveling devices is driven at a lower speed than the other, and the speed difference between the left and right traveling devices causes the body to make a gentle turn. By switching the turning transmission mechanism to the reverse rotation transmission state, and switching one of the left steering clutch mechanism and the right steering clutch mechanism to the straight-on engagement state and the other to the turning-on engagement state, one of the left and right traveling devices moves forward. On the other hand, the other is driven to the reverse side, and the fuselage turns by a reverse drive of the left and right traveling devices.

[0003] In this type of work vehicle, conventionally, an inwardly expanding friction brake acting on the left and right turning gears is provided, the friction brake is switched to the inbound side, the turning transmission mechanism is switched to the off state, and a left steering clutch is provided. By switching one of the mechanism and the right-hand steering clutch mechanism into the straight-in state and the other into the turning-in state, the brake is applied to one traveling device, and the traveling device on the brake side is turned inside. It was possible to make the aircraft turn the brakes.

[0004]

Conventionally, it is necessary to apply a brake to the traveling device inside the turn against the traveling of the vehicle by driving the traveling device on the outside of the turn. Due to the adoption, a large brake that exerts a strong braking force was required as a turning brake. SUMMARY OF THE INVENTION An object of the present invention is to provide a traveling power transmission for a working vehicle that can adopt a relatively small swing brake and can perform a brake swing while easily selecting a swing mode in operation.

[0005]

The constitution, operation and effect of the invention according to claim 1 are as follows.

[Structure] A left-hand drive that can be switched between a straight drive-on state in which a left-hand drive gear for driving the left-hand drive is linked to a straight-ahead transmission gear and a turning-on state in which the left-hand drive gear is linked with a left-turn gear. Equipped with a steering clutch mechanism and can be switched between a straight-in state where the right-hand drive gear for driving the right-hand drive is linked to the straight-ahead transmission gear and a turning-in state where the right-hand drive gear is linked with the right-turn gear. A reverse transmission state in which a right steering clutch mechanism is provided, and the rotational power of the drive shaft is transmitted in the reverse direction by the intermediate transmission shaft to rotate the left turning gear and the right turning gear in the rotation direction opposite to that of the straight transmission gear. A low-speed transmission state in which the rotational power of the drive shaft is transmitted at a reduced speed to rotate the left turning gear and the right turning gear in the same rotational direction as the linear transmission gear at a lower speed than the linear transmission gear; Forward from drive shaft In a traveling transmission for a working vehicle having a turning transmission mechanism capable of switching transmission to a left turning gear and a right turning gear to an uninterrupted state, a meshing type acting on the left turning gear and the right turning gear is provided. A swing brake, a spring for biasing the swing brake toward the entrance side, and a mode selection lever that can swing freely around one axis at a brake swing position, a pivot swing position, and a gentle swing position. A switching operation unit of the turning transmission mechanism and an operating unit of the turning brake are linked to the mode selection lever by a link mechanism, and when the mode selection lever is operated to a brake turning position, the turning brake is turned on. A brake turning mode in which the spring is switched to the entry side by the spring and the turning transmission mechanism is in the disengaged state appears, and a mode selection mode is displayed. Is turned to the pivot turn position, the turning brake is switched to the cut side by the lever operation force, and the turning transmission mechanism appears in the reverse rotation transmission state, and the mode selection lever slowly turns. The link mechanism is configured such that when operated to the position, the turning brake is switched to the cut side by the lever operating force, and a slow turning mode in which the turning transmission mechanism is in a low speed transmission state.

[Operation] When one mode selection lever is operated, the turning transmission mechanism and the turning brake are operated for the link mechanism and the spring, and the super pivot turning mode, the gentle turning mode or the brake turning mode is set. Will appear. When one of the left steering clutch mechanism and the right steering clutch mechanism is switched to the straight-on engagement state and the other to the turning-on engagement state in the state where the super pivot turn mode is displayed, the left and right traveling devices mutually move. The aircraft is driven in the reverse direction and the aircraft makes a pivot turn. In the state in which the gentle turning mode is displayed, when one of the left-hand steering clutch mechanism and the right-hand steering clutch mechanism is switched to the on-state for straight traveling, and the other is switched to the on-state for turning,
One of the traveling devices is driven at a lower speed than the other traveling device, and the body turns slowly. When one of the left-hand steering clutch mechanism and the right-hand steering clutch mechanism is switched to the straight-on engagement state and the other to the turning-on engagement state in the state in which the brake swing mode is displayed, one of the traveling devices is driven. At the same time, the brake is applied to the other traveling device, and the airframe makes a brake turn.

When the brake swing mode is selected, the swing brake is switched to the entrance side by the urging force of the spring. For this reason, even if the movable brake body of the swing brake is in a phase in which it is difficult to engage with the fixed brake body, and the swing brake is difficult to switch to the entrance side,
In the meantime, the spring holds the switching operation force, and thereafter, as the movable brake body rotates and reaches an appropriate phase,
The operating force held by the spring engages with the fixed-side brake body, and the turning brake switches to the entry side naturally. When selecting the gentle turning mode or the super pivot turning mode, the turning brake is switched to the cut side by the lever operating force, and even if the cutting resistance due to the engagement between the movable brake body and the fixed brake body is strong, Is switched to the cut side. As a result, the left and right swing gears can be braked by the swing brakes while the swing transmission mechanism and the swing brake are switched by one mode selection lever.

Since the mode selection lever swings around one axis, the operation path of the mode selection lever can be formed as a straight path.

[Effect] Therefore, a desired turn or an appropriate turn can be selected from a pivot turn, a gentle turn, and a brake turn to quickly make a turn and to make a turn while hardly disturbing the ground. By simply operating the mode selection lever described above, and simply operating in a straight line, and simply operating without considering the engagement timing of the swing brake, the swing mode can be easily selected and turned. Further, a compact engagement type brake is adopted for achieving a desired braking force as a turning brake, so that a compact brake can be obtained.

The construction, operation and effect of the invention according to claim 2 are as follows.

[Structure] In the structure of the invention according to the first aspect, the brake turning position of the mode selection lever is determined by:
Placed between the super pivot position and the gentle turning position,
When the mode selection lever is switched from the brake turning position to the gentle turning position and the super pivot turning position, the lever operating force is transmitted to the operating portion of the turning brake, and the mode selecting lever is moved to the gentle turning position and the super pivot turning position. The link mechanism is provided with an operation adjusting mechanism for transmitting the operating force of the spring to the operating portion of the turning brake when the operation is switched from the brake turning position to the brake turning position.

[Operation] If each operation position is arranged such that the brake turning position among the brake turning position, the turning position, and the gentle turning position of the mode selection lever is located at the end of the operation path, The distance between one of the turning position and the gentle turning position and the brake turning position becomes large, and the mode selection lever must be operated against the spring at the operation position. When one of the turning mode and the gentle turning mode appears, the operating resistance generated by the spring becomes large,
The operating force required for operating the mode selection lever is increased. On the other hand, since the brake operation position is located between the super pivot turning position and the gentle turning position, the interval between the brake pivoting position of the super pivot turning position and the gentle turning position is reduced. Regardless of whether the super pivot turn mode or the gentle turn mode appears, the operating resistance generated by the spring is relatively small, and the mode selection lever can be operated relatively lightly.

[Effect] When switching from the brake turning mode to the super pivot turning mode or the gentle turning mode, the mode selection lever can be operated by lightly operating the mode selecting lever.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a driving section having a driving seat S and a driving section having an engine E located below the driving seat S, the driving section being self-propelled by a pair of left and right crawler running devices 34a and 34b. A cutting section A is connected to the front end of the machine equipped with a slab so as to be able to move up and down freely. The cutting section A raises and processes the planted grain culm of rice, wheat, etc., and also performs a cutting process. A threshing process is performed by a threshing device D provided in the traveling machine, and a combine is configured to transport and store the thresh grains from the threshing device D to a grain tank T provided in the traveling machine. is there.

A transmission case 4 having a crawler drive shaft 33a, 33b of each of the crawler traveling devices 34a, 34b rotatably provided at a lower end thereof is provided at a front portion of the traveling machine body.
The rotation output of the engine E is output from the left and right crawler drive shafts 33.
A transmission gear for driving the left and right crawler traveling devices 34a, 34b by transmitting the signals to the right and left crawler traveling devices 34a, 34b is configured as shown in FIG.

That is, the turning force of the output shaft 1 of the engine E is passed through the main clutch 2 composed of a belt tension clutch, and is supported by the upper end of the transmission case 4 by a hydrostatic type non-static transmission. The transmission is transmitted to the input shaft 3a of the hydraulic pump of the step transmission 3. Inside the transmission case 4, the rotational power of the output shaft 3 b of the hydraulic motor in the continuously variable transmission 3 is transmitted to the input shaft 6 of the auxiliary transmission M to which the shift gear 5 is attached.
And the transmission power of the output shaft 7 is transmitted to the linear transmission gear 9 by the transmission gear 8 located at the center of the three transmission gears supported by the output shaft 7 of the auxiliary transmission M so as to be integrally rotatable. It is to be transmitted. The auxiliary transmission M
A rotation transmission mechanism 10 having shift gears 11 rotatably supported integrally at both ends of the output shaft 7 is provided on both lateral sides of the linear transmission gear 9 of the rotation shaft 9a supporting the linear transmission gear 9. The turning power of the output shaft 7 is transmitted to the revolving gears 19a and 19b which are rotatably attached to the located portions. The straight transmission gear 9 and one of the left turning gears 1 of the pair of turning gears 19a and 19b.
9a is selected by the left steering clutch mechanism 20 and connected to the left traveling drive gear 30a, so that the rotational power of the straight transmission gear 9 and the left turning gear 19a is converted to the left traveling drive gear 30a.
The left traveling drive gear 30a drives the left crawler traveling device 34a via the transmission gears 31a and 32a and the crawler driving shaft 33a.
The straight transmission gear 9 and the pair of revolving gears 19a, 1
The right turning gear 19b of the driving gear 9b is selected by the right steering clutch mechanism 20 and connected to the right running drive gear 30b, so that the turning power of the straight transmission gear 9 and the right turning gear 19b is converted to the right running drive gear. The right traveling drive gear 30b drives the right crawler traveling device 34b via transmission gears 31b and 32b and a crawler drive shaft 33b.

As shown in FIGS. 2 and 4, the turning transmission mechanism 10 includes, on one end, the pair of shift gears 11 and an input gear 13 a to which the left side shift gear 11 of the pair of shift gears 11 is disengaged. An output gear 13b rotatably provided and meshed on the other end with the left turning gear 19a.
And an input gear with which an intermediate transmission shaft 13 rotatably supported by the transmission case 4 via bearings 14a and 14b and a shift gear 11 on the right side of the pair of shift gears 11 are disengaged. 1
A transmission gear 3b is provided on one end side so as to be rotatable integrally, and an output gear 13b meshing with the right turning gear 19b is provided on the other end side so as to be integrally rotatable. And an intermediate transmission shaft 13 rotatably supported via a base 14b.

As shown in FIG. 4 and the like, the output shaft 7 is
Not only for the three transmission gears 8 of the auxiliary transmission device M, but also for the collar K1 located between the output shaft 7 and the bearing, between the transmission gears and between the transmission gear and the collar K1. The sprocket is also engaged with the positioning collar K2 provided on the transmission case 4 so as to slide with respect to the transmission case 4, and the fork portion is engaged with one of the shift gears 11 so as to be relatively rotatable. Shift fork 1
5 is moved along the fork shaft 16 on which the boss 15a of the shift fork 15 is fitted, the left and right shift gears 11 slide with the output shaft 7, and the shift fork 15 is moved to the boss 15a. The positioning annular groove 1 at the left end of the three positioning annular grooves 16a to 16c provided on the fork support shaft 16 has a positioning ball 15b provided therein.
6a, the left and right shift gears 11 are connected to the corresponding input gear 1 of the intermediate transmission shaft 13.
3a, the rotating power of the output shaft 7 is reversed by the left intermediate transmission shaft 13 and transmitted to the left turning gear 19a, and is reversed by the right intermediate transmission shaft 13 and transmitted to the right turning gear 19b. Revolving gears 19a, 19b
Is also driven in the rotation direction opposite to that of the straight transmission gear 9. Shift the shift fork 15 to the positioning ball 15b
Is shifted to the neutral position engaged with the central positioning annular groove 16b of the three positioning annular grooves 16a to 16c, the left and right shift gears 11 are disengaged from the corresponding input gear 13a of the intermediate transmission shaft 13 and output shaft 13 And the power transmission to the left and right swing gears 19a and 19b is cut off.
When the shift fork 15 is set at the reduced position where the positioning ball 15b is engaged with the positioning annular groove 16c at the right end of the three positioning annular grooves 16a to 16c, both the left and right shift gears 11 correspond to the corresponding turning gears 19a, 1
9b, the rotational power of the output shaft 7 is transmitted to the left turning gear 19a by the left shift gear 11 and to the right shift gear 1a.
1 to the right turning gear 19b, so that the left and right turning gears 19a, 19b are driven in the same rotational direction as the straight transmission gear 9. At this time, due to the gear ratio relationship between the shift gear 11 and the turning gears 19a, 19b, the left and right turning gears 19a, 1
The rotation speed of 9b is lower than the rotation speed of the straight transmission gear 9.

As shown in FIGS. 4 and 6, a turning brake 12 is attached to one end of the pair of intermediate transmission shafts 13. Both the swing brake 12 attached to the left intermediate transmission shaft 13 and the swing brake 12 attached to the right intermediate transmission shaft 13 are provided on the portion 4a of the transmission case 4 that supports one end of the intermediate transmission shaft 13. And a movable brake body 12b attached to the end of the intermediate transmission shaft 13. The fixed-side brake body 12a is provided with a non-circular brake hole 12c whose periphery is uneven in the circumferential direction over the entire circumference, and is formed as a separate component from the transmission case 4 so that the fixed-side brake body 12a is provided in an assembly hole of the transmission case portion 4a. It is fitted so that it is prevented from coming off by the retaining ring 12d, and is fixed to the transmission case portion 4a so as not to be rotatable by engagement with the transmission case portion 4b forming the straight portion of the mounting hole. It is constituted by a ring member.
The movable-side brake body 12b is constituted by a non-circular member having a non-circular portion 12e on one end side, the outer peripheral surface of which has an uneven surface similar to the brake hole 12c of the fixed-side brake body 12a. The shaft 13 is integrally rotatably and slidably mounted by spline engagement. The non-circular portion of the movable-side brake body 12b is slid by the operation fork 17 in which the fork part 17a is engaged with the other end side of the movable-side brake body 12b so as to be relatively rotatable and integrally slidable. 12e is configured to enter and exit the brake hole 12c of the fixed-side brake body 12a.

Accordingly, the left or right swing brake 1
2, the movable fork 17 is slidably operated by swinging the operation fork 17 about the axis of the rotation support shaft portion 17b, and the non-circular portion 12e of the movable fork 17 is braked by the fixed brake member 12a. When the movable brake body 12b and the fixed brake body 12a enter the hole 12c due to their non-circular shape, the movable brake body 12b and the fixed brake body 12a engage with each other so that they cannot rotate relative to each other. , 19b are braked, and when the non-circular portion 12e of the movable brake body 12b comes out of the brake hole 12c of the fixed brake body 12a, the movable brake body 12b and the fixed brake body 12a are released.
Can rotate relative to the turning gear 19.
The brakes are released so as to release the brakes a and 19b.

As shown in FIG. 5, the base end of a fork operating lever 41 whose free end is engaged with a boss 15a of a shift fork 15 for slidingly operating the shift gear 11 by an operating pin 40 is used as a rotary support shaft. The switch case 42 is rotatably supported by the transmission case 4, and a plate body is attached to the end of the rotation support shaft 42 protruding outside the transmission case so as to be integrally rotatable, and a switching operation unit 43 is provided. By swinging the operation unit 43, the shift fork 15 can be slid and the turning transmission mechanism 10 can be switched. FIG.
As shown in the drawings, in the left and right turning brakes 12, the base end of the operation arm is rotatably attached to the end of the rotation support shaft portion 17b of the operation fork 17 protruding outside the transmission case. The operation fork 17 can be oscillated by operating the brake operation unit 44 by swinging the brake operation unit 44.
The switching mechanism 43 of the turning transmission mechanism 10 and the brake operating sections 44 of the left and right turning brakes 12 are each provided with a single mode selection lever 70. It is configured to be operated by. This operation mechanism is configured as shown in FIGS.

That is, the mode selection lever 70 has a lever support shaft 7 whose boss 70 a is fixed to the lever bracket 71.
As shown in FIG. 9, a linear operation path as shown in FIG. 9 is supported by the lever support shaft 72 so as to be swingable by being externally fitted to the outer periphery 2 so as to be relatively rotatable. 77 and the lever support shaft 72.
Swinging operation in the front-rear direction of the aircraft around one axis 72a in a direction along the lateral direction of the aircraft, and a super-spinning turning position S arranged at the front end of the aircraft on the operation path 77; 77
And a brake turning position B disposed at an intermediate portion of the operation path 77 so as to be located between the gentle turning position K and the super turning position S. And so on.

The boss 70a of the mode selection lever 70
Has one end side rotatably connected to the other and swings around a shaft 72a together with a mode selection lever 70.
0 and a first interlocking rod 85 having one end connected to the oscillating link 80 and the other end connected to the switching operation section 43 of the turning transmission mechanism 10.
The turning-side link mechanism 87 is configured so that 0 is linked with the switching operation section 43 of the turning transmission mechanism 10. The swing link 80, a second interlock rod 81 having one end connected to the swing link 80, and an operation adjusting mechanism 100 having an input member 101 connected to the other end of the second interlock rod 81.
A third interlocking rod 82 having one end connected to the output member 102 of the operation adjusting mechanism 100, a rotary transmission shaft 86 having an input arm 86a connected to the other end of the third interlocking rod 82, The left output arm 86b of the pair of left and right output arms 86b provided so that the rotation transmission shaft 86 is rotatable integrally with the operation unit 44 of the left rotation brake 12.
And a timing adjustment mechanism 90 that links the right output arm 86b of the pair of output arms 86b to the operating section 44 of the right turn brake 12, and a mode selection lever 70.
A brake-side link mechanism 83 for interlocking with the operating section 44 of the two turning brakes 12 is constituted. The mode selecting lever 70 is connected to the turning transmission mechanism 10 and the both turning brakes by the brake side link mechanism 83 and the turning side link mechanism 87. 12
A link mechanism 84 linked to the operation units 43 and 44 of FIG.

The brake spring 8 extends over an operation arm 86c extending integrally and rotatably from the rotary transmission shaft 86 and a spring support 88 supported on the body portion.
9 is attached. The brake spring 89 swings and biases the operation arm 86c, thereby swingingly biasing the operation portions 44 of the two turning brakes 12 to the entry side via the rotary transmission shaft 86 and the timing adjustment mechanism 90. , The left and right turning brakes 12 are urged inward.

When the swing-side link mechanism 87 swings the mode selection lever 70, the lever operation force is transmitted to the switching operation section 43, and the shift fork 15 is slid by the lever operation force. When the turning position S is reached, the shift fork 15 is set to the reverse position. When the mode selection lever 70 is set to the brake turning position B, the shift fork 15 is set to the neutral position, and the mode selection lever 70 is set to the gentle turning position K. If so, the shift fork 15 is set to the deceleration position.

As shown in FIG. 7, FIG. 10, FIG.
The operation adjusting mechanism 100 includes an output member 102 supported by the support shaft 103 so as to be swingable by a boss portion 102a externally rotatably fitted to a support shaft 103 parallel to the rotation transmission shaft 86. Output member 10 of the spindle 103
The input member 101 is slidably attached to an end 103a of an oval cross section protruding from the second boss 102a by an assembling elongated hole 101a.

An arc-shaped elongated hole 1 centered on the axis of the support shaft 103 is provided on both lateral sides of the boss portion 102a of the output member 102.
02b, and the transmission projections 101b, 1 which are respectively slidably and rotatably inserted into the pair of long holes 102b.
01c is fixed to the input member 101. When the mode selection lever 70 is swung, the input member 101 is moved relative to the support shaft 103 and the output member 102 in a direction perpendicular to the axis of the support shaft 103 due to the lever operation force and the assembly long hole 101a. Moving. At this time, the input member 1
Reference numeral 01 moves while being prevented from rotating with respect to the support shaft 103 because of the oval cross section of the support shaft end 103a to which it is attached.

When the mode selection lever 70 is at the brake turning position B, as shown in FIG.
1 becomes the neutral position. Then, the brake spring 89 is moved to the brake-engaged position where the output member 102 is supported by the pair of transmission projections 101b and 101c of the input member 101.
And allows the brake spring 89 to operate both swing brakes 12 inward.

When the mode selection lever 70 is switched from the brake turning position B to the pivot turning position S, FIG.
As shown in (b), the input member 101 is pushed down from the neutral position due to lever operating force. Then
One of the transmission projections 101c of the input member 101 is the output member 1
02 is pressed against the brake spring 89, whereby the output member 102 is brought to the brake release position, and the operation of the two turning brakes 12 is performed via the third interlocking rod 82, the rotation transmission shaft 86, and the timing adjustment mechanism 90. The part 44 is operated to the cut side.

When the mode selection lever 70 is switched from the brake turning position B to the gentle turning position K, FIG.
As shown in FIG. 7, the input member 101 is pulled up from the neutral position due to the lever operation force. Then, the other transmission projection 101b of the input member 101 presses the output member 102 against the brake spring 89, whereby the output member 102 is brought to the brake release position and the third interlocking rod 82 and the rotary transmission shaft 86 , Timing adjustment mechanism 9
The operation unit 44 of the two turning brakes 12 is operated to the cut side via the zero.

Thus, when the mode selection lever 70 is operated to switch from the brake turning position B to the gentle turning position K and the super pivot turning position S, the operation adjusting mechanism 100 turns the operating force of the mode selecting lever 70 to both the turning positions. The operation is transmitted to the operation unit 44 of the brake 12, the left and right turning brakes 12 are operated to the cut side by lever operating force, and the mode selection lever 70 is switched from the gentle turning position K and the super pivot turning position S to the brake turning position B. Then, the operation force of the brake spring 89 is transmitted to the operation unit 44 of both the turning brakes 12,
The left and right turning brakes 12 are operated to enter by the urging force of the brake spring 89.

As shown in FIG. 7, FIG. 13, FIG.
Both the left timing adjustment mechanism 90 and the right timing adjustment mechanism 90 are connected to the output arm 8 of the rotary transmission shaft 86.
A transmission in which a rod portion on one end side is rotatably connected to 6b by a connection pin 91 and a yoke portion 93a on the other end side is connected to the brake operation portion 44 by a connection pin 92 fixed to the brake operation portion 44. Body 93 and output arm 86
One end is connected to the connection pin 91 on the b side, and the other end is connected to the connection pin 92 of the brake operation part 44, so that the adjustment spring 94 is connected across the output arm 86b and the brake operation part 44. It is constituted by. A pin hole 93b connected to the brake operating portion 44 of the yoke portion 93a of the transmission 93 is formed as an elongated hole into which the connecting pin 92 is slidably inserted. When the transmission pin 93 is located at the upper end side of the pin hole 93b, the transmission 93 is connected to the output arm 86b and the brake operating section 44.
It is installed over.

As a result, the timing adjustment mechanism 90
When the mode selection lever 70 is operated, the turning brake 1
2 is operated by the adjusting spring 94 and the transmission 93 as follows. That is, when the mode selection lever 70 is operated to the brake turning position B, the operation force of the brake spring 89 transmitted to the output arm 86b of the rotation transmission shaft 86 causes the spring 94 to be pulled, and the spring 94 that is pulled is operated. Brake operation unit 44
Switch to the side with the brake. That is, even if the mode selection lever 70 is operated to the brake turning position B and one of the left and right turning brakes 12 is switched to the ingress side, the movable turning body 1 is turned on the other turning brake 12.
If 2b is in a phase that is difficult to engage with the fixed-side brake body 12a and it is difficult to switch to the entrance side, the spring 94 is elastically deformed to hold the switching operation force, and thereafter the movable-side brake body 12b is As shown in FIG. 14B, the fixed brake body 1 is rotated by the operating force held by the spring 94,
An operation is performed so that the turning brake 12 naturally switches to the entry side by engaging with 2a. And the mode selection lever 7
When 0 is operated to the pivot position S or the gentle turning position K,
As shown in FIG. 14, the transmission 93 is pushed by the lever operation force transmitted to the output arm 86b of the rotary transmission shaft 86.
As shown in (a), the transmission 93 that is pushed and operated is the pin hole 9.
At the upper end side of 3b, the connecting pin 92
2, the brake operation unit 44 is switched to the brake release side.

Therefore, the link mechanism 84 operates the mode selection lever so that the swing transmission transmission mechanism 10 and the left and right swing brakes 12 are switched by the lever operation force of the mode selection lever 70 and the operation force of the brake spring 89. 70 is linked to the switching operation section 43 of the turning transmission mechanism 10 and the operation section 44 of the left and right turning brakes 12, and the mode selection lever 70 is moved to the super pivot position S.
By switching between the three operating positions, namely, the brake position B and the gentle turning position K, it is possible to selectively appear in the pivot turn mode, the brake turning mode, and the gentle turning mode.

That is, when the mode selection lever 70 is swung along the operation path 77 to operate the gentle turning position K, the switching operation section 43 switches the shift fork 15 to the deceleration transmission position, Operates the movable brake body 12b to the cut side.
Thus, the left and right shift gears 11 mesh with the corresponding turning gears 19a and 19b, and the turning transmission mechanism 1
0 transmits the turning power of the output shaft 7 to the left turning gear 19a by the left shift gear 11 and to the right turning gear 19b by the right shift gear 11, respectively, and also the gear ratio between the shift gear 11 and the turning gears 19a, 19b. The low speed transmission state is set so that transmission is performed at a reduced speed according to the relationship (1), and the left and right turning gears 19a and 19b are rotated in the same rotational direction as the straight transmission gear 9 at a lower speed than the straight transmission gear 9. Then, the left and right turning brakes 12 are turned off, and the braking action on the turning gears 19a and 19b is released.

When the mode selection lever 70 is moved to the
Is operated, the switching operation unit 43 shifts the shift fork 1
5 is switched to the reverse transmission position, and the left and right brake operation parts 44 operate the movable brake body 12b to the cut side. As a result, the left and right shift gears 11 mesh with the input gear 13a of the intermediate transmission shaft 13, and the turning transmission mechanism 10 transfers the rotating power of the output shaft 7 to the left left turning gear 19a by the left intermediate transmission shaft 13 and the right intermediate transmission. The shaft 13 is brought into a reverse rotation transmitting state so as to be reversely transmitted to the right turning gear 19b and transmitted to the right turning gear 19b, respectively.
b is rotated in a rotation direction opposite to that of the straight transmission gear 9. Then, the left and right turning brakes 12 are turned off, and the braking action on the turning gears 19a and 19b is released.

When the mode selection lever 70 is operated to the brake turning position B, the switching operation unit 43 switches the shift fork 15 to the neutral position, and the brake operation unit 44 operates the movable brake body 12b to the entry side. As a result, the left and right shift gears 11 are disengaged from the input gear 13a of the intermediate transmission shaft 13 and from the turning gears 19a and 19b, and the turning transmission mechanism 10 is moved from the output shaft 7 to the left and right turning gears 1.
The transmission is cut off so as to cut off transmission to 9a and 19b. Then, the left and right turning brakes 12 are turned on, and the brakes are applied to the left and right turning gears 19a and 19b.

When the mode selection lever 70 is operated to the pivot turning position S, the brake turning position B, and the gentle turning position K, the frictional member 110 is applied to the base end side of the mode selection lever 70 to provide a movement resistance. The mode selection lever 70 is moved to each of the operation positions S,
B and K, and the operating portions 43 and 44 of the turning transmission mechanism 10 and the turning brakes 12 can be held at predetermined operating positions by holding the lever.

As shown in FIGS. 2 and 4, both the left steering clutch mechanism 20 and the right steering clutch mechanism 20
A cylindrical transmission 22 having a transmission gear 21 meshing with the traveling drive gears 30a and 30b and being fitted to the rotary shaft 9a so as to be relatively rotatable and slidable;
Meshing clutch 23 provided between one end of the transmission gear 9 and the linear transmission gear 9, and a wet multi-plate friction clutch 24 provided between the other end of the transmission 22 and the turning gears 19a and 19b. It is constituted by and.

A clutch spring 25 provided inside the end of the transmission body 22 where the friction clutch 24 is located is connected to the transmission body 22.
Is slidably biased toward the linear drive transmission gear 9, thereby switching and engaging the meshing clutch 23 to the entrance side, and
The friction clutch 24 is configured to be switched and biased to the disengagement side, and a fork portion is rotatably engaged with a portion of the transmission body 22 located between the friction clutch 24 and the transmission gear 21 and the transmission case 4 By operating the operation fork 26 which is swingably supported by the swinging operation, the transmission body 22 slides due to this operation force and the operation force by the clutch spring 25, and the friction clutch 24
And the first turning position in which the meshing clutch 23 and the friction clutch 24 are both turned off, and the friction clutch 24 is turned in while the meshing clutch 23 is turned off. It is configured to be switched to the second turning position to be operated. In this manner, the transmission body 22 slides to move straight,
Regardless of the turning position or the second turning position, the transmission gear 21 is set by setting the tooth width of the transmission gear 21 and the traveling drive gears 30a and 30b and the sliding stroke of the transmission 22. Are the traveling drive gears 30a, 30b
Maintains meshing state.

Thus, the left-hand steering clutch mechanism 20 and the right-hand steering clutch mechanism 20 switch the transmission 22 to the straight-ahead position to operate the traveling drive gears 30a, 3a.
0b is the transmission gear 21, the transmission body 22, the meshing clutch 2
The driving device 34a and 34b are driven by the rotation power from the straight transmission gear 9 so as to be linked with the straight transmission gear 9 via the third transmission gear 9. By switching the transmission 22 to the first turning position, the traveling drive gears 30a, 30b are turned off so that the transmission of the traveling drive gears 30a, 30b to the straight drive gear 9 and the turn gears 19a, 19b is cut off, and the traveling devices 34a, 34b are turned off. To neutral state. When the transmission 22 is switched to the second turning position, the driving drive gears 34a and 34b are engaged with the turning gears 19a and 19b via the transmission gear 21, the transmission 22 and the friction clutch 24 so as to be engaged with the turning. Thus, the traveling devices 34a and 34b can be driven by the turning power from the turning gears 19a and 19b, and the traveling devices 34a and 34b can be braked by the turning brake 12.

As shown in FIG. 3, the left steering clutch mechanism 2
0 and the right steering clutch mechanism 20, the transmission 22
The fork operating arm 50 is attached to the end of the rotation support shaft 26a of the fork 26 which operates the
The fork operation arm 50 is attached to a single-acting hydraulic cylinder 51 provided outside the transmission case 4 and a hydraulic cylinder 5
The hydraulic cylinder 51 is configured to swing by a spring (not shown) for urging the hydraulic cylinder 51 toward the shortening side.
Thus, the transmission 22 can be slidably operated. The hydraulic cylinder 51 of the left steering clutch mechanism 20
And the hydraulic cylinder 51 of the right steering clutch mechanism 20 via one electromagnetically operated control valve 52 to the hydraulic pump P.
The hydraulic oil is supplied from both hydraulic cylinders 5
A drain oil passage 53 is connected to the drain oil passages 1 and 51, and an operating portion of a variable relief valve 54 provided in the drain oil passage 53 and an operating portion of the control valve 52 are connected by one link lever 55 by a linking mechanism 55. It is linked to 56.

The steering lever 56 is provided on the driving unit so as to be capable of swinging in the lateral direction of the body, and the neutral position N
The left first turning position L1 that has swung to the left of the neutral position N, the left second turning position L2 that has swung further to the left of the left first turning position L1, and the right of the neutral position N. The rocked right first turning position R1 and the right first turning position R
It is configured to switch to the right second turning position R2 that has swung further to the right than to the right.

When the steering lever 56 is operated to the neutral position N, the linkage mechanism 55 operates the control valve 52 to the neutral position, and the hydraulic cylinder 51 of the left steering clutch mechanism 20 is also connected to the hydraulic cylinder of the right steering clutch mechanism 20. 51 also operates the transmission 22 to the straight traveling position.

When the steering lever 56 is operated to the first left turning position L1, the linkage mechanism 55 operates the control valve 52 to the left turning position, and the hydraulic cylinder 51 of the right steering clutch mechanism 20 is not driven, so that the left steering operation is performed. Hydraulic cylinder 51 of directional clutch mechanism 20
Is driven to the extension side to slide the transmission 22 toward the left turning gear 19a. At this time, when the linkage mechanism 55 operates the variable relief valve 54 to the open side and the transmission body 22 reaches the first turning position, the drain oil passage 53 drains the hydraulic oil from the hydraulic cylinder 51 and Stop stretching. Thus, the transmission 20 of the right steering clutch mechanism 20 is in the straight traveling position, and the transmission 22 of the left steering clutch mechanism 20 is in the first turning position.

When the steering lever 56 is operated to the second left turning position L2, the linkage mechanism 55 operates the control valve 52 to the left turning position, and the hydraulic cylinder 51 of the right steering clutch mechanism 20 is not driven, so that the left steering operation is performed. Hydraulic cylinder 51 of directional clutch mechanism 20
Is driven to the extension side to slide the transmission 22 toward the left turning gear 19a. At this time, the linkage mechanism 55 operates the variable relief valve 54 to the throttle side, the relief pressure in the drain oil passage 53 increases, and the hydraulic cylinder 51 causes the transmission 22 to move to the first position.
The sliding operation can be performed further to the left turning gear 19a than the turning position. Thereby, the transmission 22 of the right steering clutch mechanism 20 is at the straight-ahead position, and the transmission 22 of the left steering clutch mechanism 20 is at the second turning position.

When the steering lever 56 is moved to the first right turning position R1, the linkage mechanism 55 operates the control valve 52 to the right turning position, and the hydraulic cylinder 51 of the left steering clutch mechanism 20 is not driven, and Hydraulic cylinder 51 of steering clutch mechanism 20
Is driven to the extension side to slide the transmission 22 toward the right turning gear 19b. At this time, when the linkage mechanism 55 operates the variable relief valve 54 to the open side and the transmission body 22 reaches the first turning position, the drain oil passage 53 drains the hydraulic oil from the hydraulic cylinder 51 and Stop stretching. Thereby, the transmission 22 of the left steering clutch mechanism 20 is in the straight traveling position, and the transmission 22 of the right steering clutch mechanism 20 is in the first turning position.

When the steering lever 56 is operated to the second right turning position R2, the linkage mechanism 55 operates the control valve 52 to the right turning position, and the hydraulic cylinder 51 of the left steering clutch mechanism 20 is not driven, and Hydraulic cylinder 51 of steering clutch mechanism 20
Is driven to the extension side to slide the transmission 22 toward the right turning gear 19b. At this time, the linkage mechanism 55 operates the variable relief valve 54 to the throttle side, the relief pressure in the drain oil passage 53 increases, and the hydraulic cylinder 51 causes the transmission 22 to move to the first position.
The sliding operation can be performed further to the right turning gear 19b than the turning position. Thus, the transmission 22 of the left steering clutch mechanism 20 is in the straight traveling position, and the transmission 22 of the right steering clutch mechanism 20 is in the second turning position.

That is, the turning transmission mechanism 10 is switched by the mode selection lever 70 to switch the turning mode between the gentle turning, the brake turning, and the pivot turn, and the steering lever 56 is connected to the left steering clutch mechanism 20 and the right. The steering of the aircraft is performed by operating the steering clutch mechanism 20.
That is, even if the mode selection lever 70 is operated to any one of the gentle turning position K, the brake turning position B, and the super turning position S, when the steering lever 56 is operated to the neutral position N,
Both the left-hand steering clutch mechanism 20 and the right-hand steering clutch mechanism 20 are brought into a straight forward engagement state, and both the left traveling drive gear 30a and the right travel drive gear 30b are driven by the straight transmission gear 9 in conjunction with the straight transmission gear 9, Left and right traveling devices 34a, 3
4b is driven in the same driving direction at the same driving speed, and the body goes straight. When the steering lever 56 is operated to the left first turning position L1 and the right first turning position R1, the operation direction of the steering lever 56 of the left steering clutch mechanism 20 and the right steering clutch mechanism 20 is opposite. The steering clutch mechanism 20 on the side of the vehicle is maintained in the straight-in state.
The driving drive gears 30a and 30b corresponding to 0 are driven by the straight transmission gear 9, and the left steering clutch mechanism 20 and the right steering clutch mechanism 20 are steered on the side equal to the operating direction of the steering lever 56. The clutch mechanism 20 enters the turning off state, and the traveling drive gears 30b and 30a corresponding to the steering clutch mechanism 20 enter a neutral state in which the traveling drive gears 9b and 19a are not interlocked with the straight transmission gear 9 or the swing drive gears 19b and 19a. The traveling device 3 on the opposite side to the operation direction of the steering lever 56
4a and 34b are driven at the same drive speed as when traveling straight, and the traveling device 3 on the side equal to the operating direction of the steering lever 56 is used.
4a and 34b enter the neutral state, and the aircraft
Traveling devices 34a, 34a,
It turns around 34b as the turning center.

When the mode selection lever 70 is operated to the gentle turning position K, a gentle turning mode is set. That is, the turning transmission mechanism 10 enters the low-speed transmission state, and the turning power of the output shaft 7 is transmitted to the left and right turning gears 19a, 19b by the engagement of the shift gear 11 and the turning gears 19a, 19b. In this gentle turning mode, the steering lever 56 is moved to the left second turning position L.
2. When operated to the second right turning position R2, of the left steering clutch mechanism 20 and the right steering clutch mechanism 20, the steering clutch mechanism 20 on the opposite side to the operating direction of the steering lever 56 is in a straight-in state. The traveling drive gears 30a and 30b corresponding to the steering clutch mechanism 20 are driven by the straight transmission gear 9, and the traveling devices 34a and 34b on the opposite side to the operation direction of the steering lever 56 travel straight. Driven at the same speed as the time, the steering clutch mechanism 20 of the left steering clutch mechanism 20 and the right steering clutch mechanism 20 on the side equal to the operating direction of the steering lever 56 enters the turning on state,
The traveling drive gears 30b, 30a corresponding to the steering clutch mechanism 20 are driven by the swing drive gears 19b, 19b in conjunction with the swing drive gears 19b, 19b. Traveling device 3
4a is driven at a lower speed than the traveling device 34b in the same driving direction as the traveling device 34b on the opposite side to the operation direction of the steering lever 56, and the speed difference between the left and right traveling devices 34a and 34b causes the body to move. Slowly turn in the direction equal to the operation direction of 56.

When the mode selection lever 70 is operated to the brake turning position B, a brake turning mode is set. That is, the turning transmission mechanism 10 enters the braking state, and the left and right turning gears 19a and 19b are braked by the corresponding turning brakes 12. In this brake swing mode,
When the steering lever 56 is operated to the left second turning position L2 and the right second turning position R2, the left steering clutch mechanism 20 and the right steering clutch mechanism 20 on the opposite side to the operating direction of the steering lever 56 are operated. The steering clutch mechanism 20 is maintained in the on-going state, and the traveling drive gears 30a and 30b corresponding to the steering clutch mechanism 20 are driven by the straight transmission gear 9, thereby causing the left steering clutch mechanism 20 and the right steering. Clutch mechanism 20
Of these, the steering clutch mechanism 20 on the side equal to the operating direction of the steering lever 56 enters the turning-on state, and the traveling drive gears 30a, 30 corresponding to the steering clutch mechanism 20 are turned.
b is interlocked with the turning drive gears 19a, 19b and is braked by the turning brake 12 via the turning drive gears 19a, 19b, so that the traveling devices 34a, 34b on the opposite side to the operating direction of the steering lever 56 travel straight. The traveling devices 34a, 34b on the side equal to the operation direction of the steering lever 56 are braked by driving at the same speed as that of the traveling device 3, and the vehicle is in a braking state in the direction equal to the operation direction of the steering lever 56.
The base turn is performed with the sides 4a and 34b inside the turn.

Move the mode selection lever 70 to the pivot position S
When the operation is performed, the operation is changed to the super-revolution turning mode. That is,
The turning transmission mechanism 10 enters the reverse rotation transmitting state, in which the turning power of the output shaft 7 is reversed by the intermediate transmission shaft 13 and transmitted to the left and right turning gears 19a, 19b. When the steering lever 56 is operated to the left second turning position L2 and the right second turning position L2 in the super pivot turning mode, the steering lever 56 of the left steering clutch mechanism 20 and the right steering clutch mechanism 20 is operated. The steering clutch mechanism 20 on the opposite side to the operation direction is maintained in the straight-in engagement state, and the traveling drive gears 30a and 30b corresponding to the steering clutch mechanism 20 are driven by the straight transmission gear 9 to perform left steering. Of the directional clutch mechanism 20 and the right steering clutch mechanism 20, the steering clutch mechanism 20 on the side equal to the operating direction of the steering lever 56 enters the turning-on state, and the traveling corresponding to the steering clutch mechanism 20 runs. Drive gear 30b,
30a is driven by the turning drive gears 19b, 19a in conjunction with the turning drive gears 19b, 19a, and the traveling devices 34b, 34 on the opposite side to the operating direction of the steering lever 56.
a and the traveling devices 34a and 34b on the side equal to the operation direction of the steering lever 56 are driven in opposite directions to each other, and the fuselage makes a pivot turn in a direction equal to the operation direction of the steering lever 56.

As shown in FIG. 13 and FIG. 14, a traction cam body 96 mounted on the switching operation portion 43 of the turning transmission mechanism 10 so as to be swingably operated by a mode selection lever 70 together therewith, One end of the shaft 86 is rotatably connected to an output arm 86b of the shaft 86.
A brake restraining mechanism 98 is constituted by a restraining rod 97 having an elongated hole 97a in the middle portion of which end 42a is slidably inserted.

A traction cam surface 96b is provided on a peripheral surface of the traction cam body 96 and has a traction release concave portion 96a formed of a notch in a part thereof. 97 at the end. FIG.
As shown in FIGS. 4 (a) and 4 (c), the switching operation section 43 operates the shift fork 16 to the reverse rotation position or the reduction position to shift the shift gear 11 to the input gear 13 of the intermediate transmission shaft 13.
a and the revolving gear 19a, the portion of the restraining cam surface 96b of the restraining cam body 96 deviated from the restraint releasing concave portion 96a matches the restraining pin 97b and the restraining cam body 9
6 acts as a stopper on the traction pin 97b, and disables the traction rod 97 from being pulled up by the output arm 86b. As shown in FIG. 14 (b), the switching operation unit 43 operates the shift fork 15 to the neutral position so that the shift gear 11 is disengaged from the input gear 13a of the intermediate transmission shaft 13 and from the turning gear 19a. When in the release position, the restraint release concave portion 96a matches the restraint pin 97b, the restraint cam body 96 releases the stopper action on the restraint pin 97b, and the output arm 86b swings to lift the restraint rod 97. Enable.

Thus, the brake restraint mechanism 98 allows the turning brake 12 to be switched to the entry side when the turning transmission mechanism 10 is in the cut-off state. And the reverse rotation transmission state prevents the turning brake 12 from being switched to the entry side.
The shift gear 11 is engaged with the input gear 13a and the swing gears 19a and 19b and the swing brake 12
Can select the turning mode while avoiding the occurrence of a state in which the brakes are applied to the turning gears 19a and 19b.

The right and left shift gears 11 are mounted on the output shaft 7 based on the mounting structure shown in FIGS. That is, the shift gear 11 is externally fitted to the oval shaft portion 7a having a cross-sectional shape of the output shaft 7 through the mounting hole 11a, and the shift gear 11 is mounted on the output shaft 7 on both sides of the shift gear 11 so that the shift gear 11 is The shift gear 11 is positioned so as to move together with the output shaft 7 with respect to the case 4. In the mounting hole 11a of the shift gear 11, when viewed in the direction along the axis of the output shaft 7, the lateral width W1 of the central portion is substantially equal to the lateral width of the shaft portion 7a, and the lateral width W2 at both ends is larger than the lateral width W1 of the central portion. The shift gear 11 and the output shaft 7 rotate relative to each other by a set rotation angle a, and are formed on the both sides of the shaft portion 7a.
And the shift gear 11 are brought into contact with each other to rotate integrally. As the set rotation angle a, the shift gear 11
To the input gear 13a of the intermediate transmission shaft 13, the revolving gear 19a,
At the time of engaging with the gear 19b, even when the teeth of the shift gear 11 and the teeth of the input gear 13a and the revolving gears 19a and 19b come into contact with each other, the gears 11, 13a, 19a and 19b are not attached to the ends in the width direction. The shift gear 11 relatively rotates with respect to the output shaft 7 due to the cam action provided by the chamfer provided, so that the teeth of the shift gear 11 easily enter between the teeth of the input gear 13a and the gears 19a and 19b. The corner is set. As the set rotation angle a,
Preferably, it is set as follows. The set rotation angle a ≧ 3
When 60 / Z (where Z = the number of teeth of the shift gear 11), the gear meshes with the mating gear within the range of the rotation angle a.

As shown in FIGS. 2 and 4, a parking brake 60 is attached to one end of the output shaft 7. The parking brake 60 is formed so as to cover the turning brake 12, and is disposed outside a brake cover 61 attached to the shock case 4 so as to be positioned outside the transmission case 4. An internal expansion type brake including a brake shoe located inside the brake drum 62 is provided.

The brake drum 62 has a square shaft portion at one end rotatably engaged with the boss portion of the brake drum 62, and the other end is externally fitted to the end portion of the output shaft 7 and is spline-engaged. The output shaft 7 is rotatably connected to the output shaft 7 by a connecting cylinder shaft 64 which is rotatably engaged with the output shaft 7.

As shown in FIG. 16, on both lateral sides of the transmission case 4, the portions 4b of the transmission case 4 through which the crawler drive shafts 33a and 33b are inserted are formed.
The transmission case 4 is supported by the traveling body by being supported by an extension end of a support arm 113 extending from the body frame 112 of the traveling body. A portion where the transmission case portion 4b on the extension end side of the support arm 113 is connected is formed as a separate component from the support arm 113, and is fastened and connected to the distal end portion 113a of the support arm 113 by a plurality of connection bolts 114. The transmission case portion 4b is clamped by the fastening force of the connection bolt 114 between the mounting member 115 configured as described above and the arm tip portion 113a. The support arm 11
3, the distal end 113a is located laterally outside the fuselage with respect to the base end connected to the fuselage frame 112. However, the support arm 113 is inclined from the fuselage frame 112 over the entire length so that stress concentration is unlikely to occur. It is formed to extend laterally outward. The boss 116 provided on the base end side of the support arm 113 is provided with the crawler traveling device 34a,
The base end side of a swing link for mounting the track frame of 34b on the body frame so as to be able to move up and down is rotatably supported.

[Other Embodiments] The present invention can be applied to a case where the structure for transmitting to the shaft having the shift gear 11 is variously different, such as a case where the auxiliary transmission M is not provided. Therefore, the output shaft 7 is referred to as a drive shaft 7.

The present invention can be applied to traveling transmission devices of various vehicles such as root crop harvesters and transport vehicles in addition to combine harvesters, and these vehicles are collectively referred to as work vehicles.

[Brief description of the drawings]

FIG. 1 is a side view of the entire combine.

FIG. 2 is a schematic view of a traveling transmission of the combine.

FIG. 3 is an explanatory view showing an operation structure of a steering clutch mechanism.

FIG. 4 is a sectional view of an arrangement portion of a shift gear, a parking brake, and a turning brake.

FIG. 5 is a sectional view of a shift gear operation unit.

FIG. 6 is a cross-sectional view of a swing brake operation unit.

FIG. 7 is a perspective view of a link mechanism for operating a shift gear and a turning brake by a mode selection lever.

FIG. 8 is a sectional view of an arrangement portion of a mode selection lever.

FIG. 9 is an explanatory diagram of an operation position of a mode selection lever.

FIG. 10 is a side view of the operation adjusting mechanism.

FIG. 11 is a sectional view of an operation adjusting mechanism.

FIG. 12 is an explanatory view showing the operation of the operation adjusting mechanism.

FIG. 13 is a front view of a timing adjustment mechanism.

FIG. 14 is an explanatory diagram showing the operation of a timing adjustment mechanism and a brake restraint mechanism.

FIG. 15 is a sectional view of a shift gear mounting structure.

FIG. 16 is a plan view of a transmission case mounting portion.

FIG. 17 is a side view of a transmission case mounting portion.

[Explanation of symbols]

 Reference Signs List 7 output shaft 9 straight drive gear 10 turning drive mechanism 12 turning brake 13 intermediate drive shaft 19a left turning gear 19b right turning gear 20 steering clutch mechanism 30a left running drive gear 30b right running drive gear 34a left running device 34b right running device 43 Switching unit of turning transmission mechanism 44 Operating unit of turning brake 70 Mode selection lever 84 Link mechanism 89 Spring 100 Operation adjusting mechanism S Super turning position B Flake turning position K Slow turning position

Claims (2)

[Claims] 1. A left steering switchable between a straight driving engagement state in which a left traveling drive gear for driving a left traveling device is interlocked with a straight transmission gear and a turning on state in which a left traveling drive gear is interlocked with a left turning gear. Equipped with a directional clutch mechanism, and can be switched between a straight-on engagement state in which the right traveling drive gear driving the right traveling device is interlocked with the straight transmission transmission gear, and a turning on state in which the right traveling drive gear is interlocked with the right turning gear. A reverse-rotation transmission state in which a right steering clutch mechanism is provided, and the rotational power of the drive shaft is transmitted in the reverse direction by the intermediate transmission shaft to transmit the left turning gear and the right turning gear in the rotation direction opposite to that of the straight transmission gear. A low-speed transmission state in which the rotational power of the drive shaft is transmitted at a reduced speed to rotate the left turning gear and the right turning gear in the same rotational direction as the linear transmission gear at a lower speed than the linear transmission gear; Turn left from axis A traveling transmission device for a working vehicle comprising a turning transmission mechanism capable of switching transmission to a gear and a right turning gear into an uninterrupted state, wherein a meshing type acting on the left turning gear and the right turning gear is provided. A swing brake, a spring for biasing the swing brake toward the entrance side, and a mode selection lever that can swing freely around one axis at a brake swing position, a pivot swing position, and a gentle swing position. A switching operation unit of the turning transmission mechanism and an operating unit of the turning brake are linked to the mode selection lever by a link mechanism, and when the mode selection lever is operated to a brake turning position, the turning brake is turned on. The brake is switched to the entry side by a spring, and at the same time, the turning transmission mechanism appears in the brake turning mode in which the turning state is turned off. When operated to the pivot position, the swing brake is switched to the cut side by the lever operation force, and the pivot transmission mechanism appears in the reverse rotation transmission state. A traveling transmission device for a working vehicle, wherein the link mechanism is configured so as to exhibit a gentle turning mode in which a turning brake is switched to a cut side by a lever operating force and the turning transmission mechanism is in a low speed transmission state when the turning brake is operated. 2. The brake turning position of the mode selection lever is disposed between the super turning position and the gentle turning position, and the mode selecting lever is moved from the braking turning position to a gentle turning position and a super turning position. When the switching operation is performed to the position, the lever operation force is transmitted to the operation unit of the turning brake, and when the mode selection lever is operated to switch from the gentle turning position and the pivot turn position to the brake turning position, the operating force of the spring is applied. The travel transmission device for a working vehicle according to claim 1, wherein the link mechanism includes an operation adjustment mechanism that transmits the operation force to an operation unit of the turning brake.