JP2002059861A - Running transmission device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a relatively small running transmission device for a work vehicle capable of turning a machine body by gentle turning, braking turning and swivel turning while selecting the braking turning by a simple operation. SOLUTION: When running drive gears 30a, 30b are connected with a progressive transmission gear 9 by a steering clutch mechanism 20, running devices 34a, 34b are driven by the progressive transmission gear 9. When the running drive gears 30a, 30b are connected with turning gears 19a, 19b by the steering clutch mechanism 20, the running devices 34a, 34b are driven by the turning gears 19a, 19b and braked by a turning brake 12 mounted on a middle transmission shaft 13. The turning brake 12 is structured as a clawing type. A spring to be pulled for turning on the turning brake 12 and a transmitter to be pushed for turning off the turning brake 12 are provided with in a mechanism for operating the turning brake 12 by a mode selection lever 70.

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 turning operation unit of the turning transmission mechanism, comprising a turning brake;
The operation unit of the swing brake is linked with a single mode selection lever via a link mechanism, and a part for transmitting the switching operation force of the link mechanism to the operation unit of the swing brake is pulled by the mode selection lever. A spring for switching the operation unit to the brake-engaged side, and a contact-type transmission body that is pushed by a mode selection lever to switch the operation unit to the brake-release side, and the mode selection lever is operated by operating the mode selection lever. A pivot turn mode in which the turning transmission mechanism is in the reverse transmission state and the turning brake is turned off, a gentle turning mode in which the turning transmission mechanism is in the low-speed transmission state and the turning brake is turned off, A brake turning mode in which the turning transmission mechanism enters the off state and the turning brake is applied. And de is arranged to alternatively emerge.

[Operation] When one mode selection lever is operated, the super pivot turning mode, the gentle turning mode, and the brake turning mode are selectively displayed, and the super pivot turning mode is displayed. In this state, when one of the left-hand steering clutch mechanism and the right-hand steering clutch mechanism is switched to the straight-in engagement state and the other to the turning-in engagement state, the left and right traveling devices are driven in opposite directions, and the aircraft is super-transmitted. Make a ground turn. 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 swing-on engagement state in the state in which the gentle turning mode is displayed, one of the traveling devices drives the other traveling. The aircraft is driven at a lower speed than the device and the aircraft 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 selecting the brake swing mode, even if the movable brake body of the swing brake is in a phase that is difficult to engage with the fixed brake body and the swing brake is difficult to switch to the entry side, the spring is elastically deformed. The switching operation force is held, and thereafter, as the movable brake body rotates, the spring engages with the fixed brake body by the operation force held by the spring, and the turning brake switches to the entry side naturally. When the turning brake is switched to the disengagement side, the transmission is pushed and the engagement of the turning brake is firmly released. 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.

[Effect] Therefore, it is possible to select a desired turn or an appropriate turn from super turning, gentle turning, and brake turning, to turn quickly or to turn while preventing the ground from being disturbed. By simply operating the mode selection lever described above and without considering the engagement timing of the turning brake, the turning mode can be easily selected and turned simply by operating. 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 structure, operation and effect of the invention according to claim 2 are as follows.

[0010] In the configuration according to the first aspect of the present invention, the mode selection lever is operated in an operation direction different from an operation direction for operating a switching operation portion of the turning power transmission mechanism to operate the turning brake. It is configured to operate the unit.

[Operation] The mode selection lever is operated in a different operation direction when switching the turning transmission mechanism and when switching the turning brake.
The user is allowed to make the selection while hardly causing an erroneous operation of performing the switching different from the intended switching.

[Effect] When the turning mode is selected, the erroneous operation described above is not easily performed, and a desired turning mode is easily selected accurately.

The structure, operation and effect of the invention according to claim 3 are as follows.

In the configuration according to the first or second aspect of the present invention, if the turning transmission mechanism is in the off state, the turning brake is allowed to be switched to the entry side, and the turning transmission mechanism is turned on. When the vehicle is in the low-speed transmission state and the reverse rotation transmission state, a brake restraint mechanism is provided to prevent the turning brake from being switched to the entry side.

[Operation] When the turning transmission mechanism is set to the low speed transmission state or the reverse rotation transmission state, the turning brake cannot be switched to the entrance side due to the brake restraining mechanism, and a situation in which the turning gear is transmitted while the brake is being applied may be caused. Can be prevented.

[Effect] The turning mode is selected while preventing the turning gear from being transmitted while being braked.

The structure, operation and effect of the invention according to claim 4 are as follows.

[Configuration] In the configuration of the invention according to any one of claims 1 to 3, if the traveling transmission is on the low speed side, the turning transmission mechanism is allowed to be switched to the reverse rotation transmission state, If the traveling transmission is on the high speed side,
A super pivot turning restraint mechanism is provided to prevent the turning transmission mechanism from being switched to the reverse transmission state.

[Operation] If the traveling transmission is set to the high speed side, the turning transmission mechanism cannot be switched to the reverse rotation transmission state due to the super turning turning restraint mechanism, and the super turning operation cannot be performed when traveling at high speed. .

[Effect] When traveling at a high speed, the vehicle can be driven so as not to be able to make a pivot turn.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, the rotational power of an output shaft 1 of an engine E is transmitted through a main clutch 2 comprising a belt tension clutch to a hydraulic pressure of a hydrostatic continuously variable transmission 3 as a main transmission. The transmission is transmitted to the input shaft 3a of the pump. Inside the transmission case 4 to which the casing of the continuously variable transmission 3 is connected, the turning power of the output shaft 3b of the hydraulic motor of the continuously variable transmission 3 is input to the input of the auxiliary transmission M to which the shift gear 5 is attached. The rotational power of the output shaft 7 is transmitted to a linear transmission gear by a transmission gear 8 located at the center of three transmission gears that are rotatably supported integrally with the output shaft 7 of the auxiliary transmission M while transmitting the rotation to the shaft 6. 9, the transmission gear 9 is supported by a turning transmission mechanism 10 having shift gears 11 rotatably supported integrally at both ends of the output shaft 7 of the auxiliary transmission M. The rotational power of the output shaft 7 is transmitted to revolving gears 19a and 19b, which are relatively rotatably attached to portions of the rotating shaft 9a located on both lateral sides of the linear transmission gear 9. By selecting the straight transmission gear 9 and the left turning gear 19a of one of the pair of turning gears 19a and 19b by the left steering clutch mechanism 20 and connecting them to the left traveling drive gear 30a, the straight transmission gear 9 The turning power of the left turning gear 19a is transmitted to the left traveling drive gear 30a, and the transmission gear 31 is transmitted by the left traveling drive gear 30a.
a, 32a and a crawler drive shaft 33a to drive the left crawler type traveling device 34a.
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 the transmission gears 31b and 32b and the crawler driving shaft 33b, thereby constituting the traveling transmission of the combine. It is.

As shown in FIG. 1 and the like, the turning transmission mechanism 10 integrally pivots one end of the pair of shift gears 11 and an input gear 13a to which the shift gear 11 on the left side of the pair of shift gears 11 is disengaged. , An output gear 13b meshing with the left turning gear 19a is rotatably provided on the other end side, and is rotatably supported by the transmission case 4 via bearings 14a and 14b. 13 and the pair of shift gears 1
An input gear 13a with which the right shift gear 11 is disengaged is integrally rotatably provided at one end, and an output gear 13b meshing with the right turning gear 19b is integrally rotatable at the other end. And an intermediate transmission shaft 13 rotatably supported by the transmission case 4 via bearings 14a and 14b.

As shown in FIG. 3 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, the rotation speed of the left and right swing gears 19a, 19b is lower than the rotation speed of the straight transmission gear 9 due to the gear ratio relationship between the shift gear 11 and the swing gears 19a, 19b.

As shown in FIG. 3 and the like, a turning brake 12 is attached to one end of the pair of intermediate transmission shafts 13.
Swing brake 12 attached to left intermediate transmission shaft 13
The turning brake 12 attached to the right intermediate transmission shaft 13 also has a fixed brake body 12 provided at a portion 4 a of the transmission case 4 supporting one end of the intermediate transmission shaft 13.
a and a movable brake body 12b attached to the end of the intermediate transmission shaft 13. As shown in FIGS. 3 and 5, the fixed-side brake body 12 a is formed as a separate part from the transmission case 4 so as to include a non-circular brake hole 12 c whose periphery is uneven in the circumferential direction over the entire circumference. Into the mounting hole of the transmission case portion 4a so as to be prevented from coming off by the retaining ring 12d, and the transmission case portion 4a is engaged with the transmission case portion 4b forming the linear portion of the mounting hole. It is constituted by a ring member which is fixed so that it cannot rotate. 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 movable brake body 1 is moved by the operation fork 17 in which a fork portion 17a is engaged with the other end side of the movable brake body 12b so as to be relatively rotatable and integrally slidable.
2b, the non-circular portion 1
2e is configured to enter and exit the brake hole 12c of the fixed brake body 12a.

Thus, 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. 4, 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 rotating 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 FIG.
A base end side of the operation arm is rotatably attached to an end of the rotation support shaft portion 17b of the operation fork 17 protruding outside the transmission case, and a brake operation portion 44 is provided.
By swinging the brake operating portion 44, the operating fork 17 can be swingably operated to switch the turning brake 12, and the switching operating portion 43 of the turning transmission mechanism 10 is connected to the left and right The brake operation unit 44 of each of the turning brakes 12 is configured to be operated by an operation mechanism having one mode selection lever 70. This operation mechanism is shown in FIGS.
0.

That is, the mode selection lever 70 has a cross section in which a mounting cylinder portion 73a on the base end side is rotatably fitted to a lever support shaft 72 provided on a lever bracket 71 fixed to the driving section. A base-side lever portion 73 formed of a U-shaped sheet metal member; and a front-end-side lever portion 74 formed of a sheet metal member having a boss portion 74a rotatably connected to a front end side of the base side lever portion 73 by a connection shaft 75. As a result, the lever shaft 71 swings with respect to the lever bracket 71 around the body laterally oriented axis 72 a of the lever support shaft 72, and the body lateral direction around the axis 75 a of the connection shaft 75 which is not parallel to the axis 72 a. The lever is configured to be freely bendable, and is operated to swing along the guide groove 77 of the lever guide plate 76 in the front-rear direction and the lateral direction by an operation portion 74b provided on the distal end side lever portion 74. It is so.

A swing link 80 provided at the base of the base side lever portion 73 so as to swing with the base end side lever portion 73 around the shaft center 72a;
The mode selection lever 70 is interlocked with the switching operation unit 43 by a transmission-side link mechanism including an interlocking rod 81 that is interlocked with the switching operation unit 43, and the mode selection lever 70 is moved around the axis 72a in the longitudinal direction of the machine. The switching operation unit 43 can be switched by performing a swing operation.

A swing link 82 provided on the boss portion 74a of the distal lever portion 74 so as to swing together with the distal lever portion 74 around the shaft center 75a with respect to the proximal lever portion 73, A link rod 83 having one end connected to the moving link 82, and a portion where the other end of the link rod 83 is connected to the free end and the distal lever 74 of the proximal lever 73 is connected. And the mounting cylinder 73
intermediate swing link 8 which is swingably supported between the intermediate swing link 8 and a.
4, an interlocking rod 85 having one end connected to the intermediate swing link 84, a rotary transmission shaft 86 having the other end connected to the input arm 86a, and an integral part of the rotary transmission shaft 86. A timing adjustment mechanism 90 for linking a left output arm 86b of a pair of left and right output arms 86b rotatably provided to the brake operation unit 44 of the left turn brake 12, and the rotation transmission shaft 86;
Output arm 86 on the right side of the pair of output arms 86b
b by a brake side link mechanism 87 comprising a timing adjustment mechanism 90 that makes the brake operating portion 44 of the right-hand turning brake 12 interlock with the mode selection lever 7.
The left and right brake operation units 44 can be switched by operating the mode selection lever 70 in the lateral direction of the body around the axis 75a in conjunction with the left and right brake operation units 44.

That is, the mode selection lever 70 is swung along the portion 77a of the guide groove 77 along the longitudinal direction of the body and the portion 77b along the lateral direction of the body, and is positioned on the front end side of the longitudinal portion 77a. When operated to the gentle turning position K, the switching operation section 43 switches the shift fork 15 to the deceleration transmission position, and the brake operation section 44 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 10 applies the turning power of the output shaft 7 to the left turning gear 19a by the left shift gear 11 and to the left turning gear 19a by the right shift gear 11. The power is transmitted to the right swing gear 19b, and the shift gear 1
1 and the rotation gears 19a, 19b, so that the transmission is in a low-speed transmission state so as to reduce the transmission speed and transmit the rotation gears 19a, 19b on the left and right in the same rotational direction as the straight transmission gear 9. Rotate at a lower speed than 9. Then, the left and right turning brakes 12 are turned off, and the turning gear 1 is turned off.
Release the braking action on 9a, 19b.

When the mode selection lever 70 is moved to the rear pivot position S located at the rear end side of the front-rearward portion 77a of the guide groove 77,
Is operated, the switching operation unit 43 shifts the shift fork 1
5 is switched to the reverse rotation transmission position, and the brake operation unit 44 operates 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 makes a reverse rotation transmission state in which the right and left rotation gears 19b are transmitted to the right rotation gear 19b in a reverse direction, and the left and right rotation gears 19a and 19b are rotated in a rotation direction opposite to that of the straight transmission gear 9. And
The left and right swing brakes 12 are turned off, and the swing gear 19
Release the braking action on a, 19b.

When the mode selection lever 70 is operated to the brake turning position B located at the end of the guide groove 77 opposite to the side communicating with the front-rearward portion 77a of the lateral portion 77b, the switching operation portion 43 is moved to the shift fork. 15 is switched to the neutral position, and the brake operation unit 44 operates the movable brake body 12b to the entrance side. This allows
The left and right shift gears 11 are the input gears 13 of the intermediate transmission shaft 13.
a and 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 19a and 19b.
It is cut off so as to cut off the power transmission. Then, the left and right turning brakes 12 are turned on, and the left and right turning gears 19 are turned on.
a, Apply brakes to 19b. At this time, the urging force of a lever spring 88a attached to a spring support shaft 88 attached to the base lever 73 as shown in FIG. As shown in the figure, the mode selection lever 70 can be held at the brake turning position B due to the urging force of the input urging spring 89 connected to the input arm 86a of the rotary transmission shaft 86, and the left and right turning brakes 12 are moved to the input side. Can be held.

As shown in FIGS. 9 and 10, both the left timing adjustment mechanism 90 and the right timing adjustment mechanism 90 have a rod part at one end attached to an output arm 86 b of the rotary transmission shaft 86. The yoke portion 93a on the other end is fixed to the brake operating portion 44 by a connecting pin 92.
The one end is connected to the transmission pin 93 connected to the output arm 86b and the connection pin 91 of the output arm 86b, and the other end is connected to the connection pin 92 of the brake operation section 44, so that the output arm 86b and the brake operation are performed. It is constituted by a spring 94 connected to the portion 44.
A pin hole 93b connected to the brake operating portion 44 of the yoke portion 93a of the transmission 93 is inserted into the connecting pin 92.
When the brake operating portion 44 is in the cut position and the connecting pin 92 is positioned at the upper end side of the pin hole 93b, the transmission 93
Are mounted over the output arm 86b and the brake operation unit 44.

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 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 lever operation force transmitted to the rotation transmission shaft 86 via the swing link 82, the intermediate swing link 84, and the interlock rod 85 of the link mechanism 87. Then, the spring 94 is pulled, and the brake operating unit 44 is switched to the brake-engaged side by the pulled spring 94. That is, the mode selection lever 7
If the movable brake body 12b is in a phase in which the movable brake body 12b is hardly engaged with the fixed brake body 12a even if the swing brake 12 is operated to the brake swing position B, and the swing brake 12 is hard to switch to the entrance side, the spring 94 Elastically deforms to hold the switching operation force, and thereafter, as the movable side brake body 12b rotates, the operating force held by the spring 94 causes the fixed side brake body 12a to rotate as shown in FIG. An operation is performed so that the turning brake 12 automatically engages and switches to the entrance side. When the mode selection lever 70 is operated on the front-rearward portion 77 a of the guide groove 77, the rotation transmission shaft 8 via the swing link 82, the intermediate swing link 84, and the interlocking rod 85 of the link mechanism 87.
6, the transmission 93 is pushed by the lever operating force transmitted to the connecting pin 92, and as shown in FIG. 10 (a), the driven transmission 93 abuts on the connection pin 92 at the upper end side of the pin hole 93b. The brake operation unit 44 is switched to the brake release side via 92.

As shown in FIG. 1 and the like, both the left steering clutch mechanism 20 and the right steering clutch mechanism 20 include a transmission gear 21 meshing with traveling drive gears 30a and 30b, and have a relative rotation with respect to the rotating shaft 9a. And a cylindrical transmission body 22 slidably fitted to the outside, a meshing clutch 23 provided between one end of the transmission body 22 and the straight-ahead transmission gear 9, and the other end side of the transmission body 22. And the revolving gear 19
a, 19b and a wet, multi-plate type friction clutch 24.

The clutch spring 25 provided inside the end of the transmission 22 where the friction clutch 24 is located
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, 30a.
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. 2, 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 in the driving section so as to be capable of swinging in the lateral direction of the machine body, and at 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, and 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 moved 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 super turning, and the steering lever 56 is used to switch the left steering clutch mechanism 20 to 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. 9 and FIG. 10, 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, Output arm 8 of shaft 86
A brake restraining mechanism 98 is constituted by a restraining rod 97 having an elongated hole 97a at an intermediate portion thereof, one end of which is rotatably connected to 6b and the end 42a of the rotary support shaft 42 is slidably inserted. It is.

A traction cam surface 96b is provided on the peripheral surface of the traction cam body 96. The traction cam surface 96b is provided with a traction release concave portion 96a formed of a notch. 97 at the end. FIG.
As shown in FIGS. 0 (a) and (b), the switching operation unit 43 operates the shift fork 16 to the reverse rotation position or the deceleration 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. 10B, the switching operation unit 43 operates the shift fork 15 to the neutral position to engage the shift gear 11 in a state where the shift gear 11 is disengaged from both the input gear 13a of the intermediate transmission shaft 13 and 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 disengaged 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.

As shown in FIGS. 6, 8 and the like, a restraining pin 101 provided at the base of a shift lever 100 that switches the sub-transmission device M by operating the shift gear 5 of the sub-transmission device M, One end is provided with an elongated hole 102a into which the restraining pin 101 is slidably inserted, and the other end is connected to the base side lever portion 73 by a connecting pin 103 provided on the base side lever portion 73 of the mode selection lever 70. Retraction rod 10 rotatably connected
2 form the super pivot turning restraint mechanism 104.

When the shift lever 100 is at the high-speed position H among the high-speed position H, the medium-speed position M, the neutral position N, and the low-speed position L, the check pin 101 is moved to the check rod 10 at the end of the slot 102a.
2, the mode selection lever 70 cannot be switched to the pivot position S. When the shift lever 100 is at an operation position other than the high-speed position H among the high-speed position H, the medium-speed position M, the neutral position N, and the low-speed position L, the traction pin 101 acts as a stopper on the traction rod 102 by the action of the elongated hole 102a. Is released, and the mode selection lever 70 is allowed to be operated to any of the gentle turning position K, the brake turning position B, and the super pivot turning position S. When the shift lever 100 is switched to the high-speed position H when the mode turning lever 70 is at the pivot turning position S, the restraining pin 101 is moved by the lever operating force.
At the end of 02a, the mode selection lever 70 is operated so as to deviate from the pivot point S by pressing the restraint rod 102.

Thus, the super pivot turning restraint mechanism 104
Allows the turning transmission mechanism 10 to be switched to the reverse rotation transmission state if the auxiliary transmission M is in a medium speed or low speed state lower than the high speed state. In the high speed state, the turning transmission mechanism 10 is prevented from being switched to the reverse rotation transmitting state. Further, when the sub transmission device M is switched to the high speed state, the turning mode is set to the super pivot turning. Is selected, the selection is automatically canceled. When the vehicle is driven at a high speed on the sub-transmission device M on a road or the like, the vehicle is driven while the super-revolution is not allowed.

As shown in FIG. 7, FIG. 11, etc., the detection object 1 made of a bent rod material formed so that both ends are bent at the distal end lever portion 74 of the mode selection lever 70.
06, and the operation unit 107a is attached to the detection object 106.
The detection switch 107 which contacts the lever guide plate 7
6 is fixed to the back side. When the mode selection lever 70 is in the operation positions of the gentle turning position K, the brake turning position B, and the super turning position S, the detection target body 106 is disengaged from the operation unit 107a of the detection switch 107 and the detection switch 107
Is on the cut side. If the mode selection lever 70 is at a position deviating from each of the gentle turning position K, the brake turning position B, and the super pivot turning position S, the detection target 106 contacts the operation unit 107a of the detection switch 107 and is detected. The switch 107 is on the entry side. The detection switch 107 automatically activates the engine stop device 108 when switched to the entrance side.

That is, when the mode selection lever 70 is out of any of the gentle turning position K, the brake turning position B, and the pivot turning position S, the turning brake 12 is on the cut side and the turning transmission mechanism is provided. The ten shift gears 11 are connected to the input gear 13 a of the intermediate transmission shaft 13 and
a, 19b, is detected by the detection switch 107. When this detection is performed, the engine stop device 108 automatically stops the engine E based on the information from the detection switch 107. Let it.

As shown in FIGS. 6 and 12, a selective restraint body 110 provided on the back side of the lever guide plate 76,
A selective restraint mechanism 113 is configured by an interlocking member 112 that links the selective restraint body 110 to the shift lever 111 of the continuously variable transmission 3.

A notch 110a is provided in the selective check body 110,
Towing production part 11 located on the front and rear sides of this notch 110a
0b and a through groove 110c communicating with the notch 110a
And are provided. When the shift lever 111 is operated, the selective restraint body 110 moves in the direction along the front-rearward portion 77a of the guide groove 77 in conjunction with the shift lever 111 due to the action of the interlocking member 112, and FIG. ), The shift lever 111 is in the forward range F, the neutral position N,
When operated to the neutral position N in the reverse region R, the notch 110a coincides with the lateral portion 77b of the guide groove 77, and the selective restraint body 110 moves the mode selection lever 70 to the front-rear portion 77a of the guide groove 77. And brake turning position B
And allowed to be moved across. When the mode selection lever 70 is operated to the brake turning position B, the mode selection lever 70 enters the inside of the through-groove 110c, and as the shift of the continuously variable transmission 3 is performed, the selected check body 11 is moved.
0 is the mode selection lever 7 by the action of the through groove 110c.
It will move relative to zero. Fig. 12 (b),
As shown in (c), when the shift lever 111 is operated to an operation position other than the neutral position N among the forward movement region F, the neutral position N, and the reverse movement region R, the towing production section 110b is moved to the guide groove 7.
Mode selection lever 70 in line with the horizontal portion 77b
The mode selection lever 70 is prevented from moving from one of the brake turning position B and the front-rearward portion 77a of the guide groove 77 to the other.

Thus, the selective restraint mechanism 113 switches to the brake turning only when the continuously variable transmission 3 is switched to the neutral state to stop the traveling of the vehicle, or releases the turning of the brake. The switching of the turning brake 12 can be performed while avoiding the brake body from being easily worn as in the case of switching the turning brake 12 while rotating the movable brake body 12b.

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 attached to the mounting hole 11a.
The output shaft 7 is externally fitted to the oval shaft portion 7a, and the shift gear 11 is moved relative to the transmission case 4 by the retaining rings 7b attached to the output shaft 7 on both lateral sides of the shift gear 11. The shift gear 11 is positioned so as to move together with the shift gear 11. Shift gear 11
Of the mounting hole 11a, the horizontal width W1 of the central portion is substantially equal to the horizontal width of the shaft portion 7a when viewed in the direction along the axis of the output shaft 7, and the horizontal width W2 of both ends is larger than the horizontal width W1 of the central portion. And the shift gear 11 and the output shaft 7 rotate relative to each other by a set rotation angle a, and a portion 7 of both side surfaces of the shaft portion 7a is formed.
The gear c and the shift gear 11 come into contact with each other and rotate integrally. As the set rotation angle a, the shift gear 1
1 is the input gear 13a of the intermediate transmission shaft 13 and the revolving gear 19
a and 19b, the teeth of the shift gear 11
Even when the teeth of the input gear 13a and the teeth of the revolving gears 19a, 19b abut against each other, the gears 11, 13a, 19a, 19
The shift gear 11 relatively rotates with respect to the output shaft 7 due to the cam action by the chamfer provided at the end in the width direction of b,
Thus, a rotation angle is set so that the teeth of the shift gear 11 can easily enter between the teeth of the input gear 13a and the teeth of the revolving gears 19a and 19b. This set rotation angle a is preferably set as follows. When the set rotation angle a ≧ 360 / 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. 1 and 3, 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 on one end rotatably engaged with the boss portion of the brake drum 62, and the other end is fitted to the end of the output shaft 7 by spline engagement. 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.

[Other Embodiments] The present invention can be applied to a case where the structure for transmitting power 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 for various vehicles such as root crop harvesters and transport vehicles in addition to combine harvesters, and these vehicles are collectively referred to as working vehicles.

[Brief description of the drawings]

FIG. 1 is a schematic view of a traveling transmission of a combine.

FIG. 2 is an explanatory diagram showing an operation structure of a steering clutch mechanism.

FIG. 3 is a sectional view of an arrangement portion of a shift gear, a parking brake, and a turning brake.

FIG. 4 is a sectional view of a shift gear operation unit.

FIG. 5 is a cross-sectional view of a swing brake operation unit.

FIG. 6 is a perspective view of a link mechanism for operating a shift gear and a turning brake by a mode selection lever.

FIG. 7 is a sectional view of an arrangement portion of a mode selection lever.

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

FIG. 9 is a front view of a timing adjustment mechanism.

FIG. 10 is an explanatory diagram showing the operation of a timing adjustment mechanism and a brake restraint mechanism.

FIG. 11 is an explanatory diagram showing the operation of a detection switch.

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

FIG. 13 is a sectional view of a shift gear mounting structure.

[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 part of turning transmission mechanism 44 Operating part of turning brake 70 Mode selection lever 87 Link mechanism 93 Transmission 94 Spring 98 Brake restraining mechanism 104 Super pivot turning restraint mechanism M Transmission device for traveling

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Ryosuke Hirai 64 Ishizu-Kitacho, Sakai City, Osaka Prefecture Inside Kubota Sakai Works (72) Inventor Yuji Kato 64 Ishizu-Kitacho, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. In-house (72) Inventor Futa Ikeda 64 Ishizukita-machi, Sakai City, Osaka Pref. In the Kubota Sakai Plant (72) Inventor Shigeyuki Hayashi 64 in Ishizu-Kitamachi, Sakai-shi, Osaka Pref. In the Kubota Sakai Plant (72) Inventor Makoto Miyazaki 64 Ishizu-Kitacho, Sakai City, Osaka, Japan (72) Inventor Nobuo Yukio 64, Ishizu-Kitamachi, Sakai City, Osaka Prefecture, Kubota Sakai Factory, Inc. (72) Koji Yamagata Sakai, Osaka, Japan 64, Ishizukitamachi, Kubota Sakai Works, Ltd. (72) Inventor Katsuhide Kato 64, Ishizukitamachi, Sakai City, Osaka Prefecture F, Kubota Sakai Works Over-time (reference) 3D052 AA04 AA13 AA17 BB10 BB11 DD04 JJ06 JJ14 JJ19 JJ21 JJ22

Claims (4)

[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 turning brake, and a switching operation unit of the turning transmission mechanism and an operating unit of the turning brake are interlocked with one mode selection lever via a link mechanism, and the switching operation force of the link mechanism is controlled by the turning brake. A spring for pulling the mode selector lever to switch the operation unit to the brake-engaged side, and a contact-type transmission for pushing the mode selector lever to switch the operation unit to the brake-disengaged side. And the turning transmission mechanism is brought into the reverse transmission state by operating the mode selection lever. A pivot turn mode in which the turning brake is turned off, a gentle turning mode in which the turning transmission mechanism is in the low-speed transmission state and the turning brake is turned off, and a turning mode in which the turning transmission mechanism is in the cut state and the turning is performed. A travel transmission for a working vehicle configured to selectively show a brake turning mode in which a brake is applied. 2. An operation unit for operating the turning brake by operating the mode selection lever in an operation direction different from an operation direction for operating a switching operation unit of the turning transmission mechanism. The traveling power transmission for a work vehicle according to claim 1. 3. When the turning transmission mechanism is in the disengaged state, the turning brake is allowed to be switched to the entry side, and when the turning transmission mechanism is in the low speed transmission state and the reverse rotation transmitting state, the turning is performed. 3. The traveling power transmission for a working vehicle according to claim 1, further comprising a brake restraint mechanism for preventing a brake from being switched to an entrance side. 4. If the traveling transmission is on a low speed side, the turning transmission mechanism is allowed to be switched to the reverse transmission state. If the traveling transmission is on a high speed side, the turning transmission mechanism is reversed. The traveling power transmission for a work vehicle according to any one of claims 1 to 3, further comprising a super pivot turning restraint mechanism for preventing the power transmission state from being switched to a transmission state.