JPH0790790B2 - Work vehicle - Google Patents

Description

The present invention relates to a structure of a traveling transmission system in a working vehicle such as a combine.

[Conventional technology]

Some combine trucks, which are one of the work vehicles, are provided with a pair of left and right crawler type traveling devices as a traveling device, and are configured so that one traveling device is braked to make a turning turn. The structure is as follows.

In other words, as shown in FIG. 8, when the left and right side gears (21L) and (21R) that transmit power to the left and right traveling devices (not shown) are both engaged with the transmission side gear (19), both traveling devices are powered. Are input gears (23R), (23L) and axles (22R), (22
It will flow in the forward direction via L) and the aircraft will go straight.
Then, for example, by sliding the left side gear (21L) to engage with the left braking side gear (26L), and operating the side brake (28) of the left braking side gear (26L),
The structure is such that the left traveling device is braked and the aircraft turns to the left.

Also, for the left side gear (21L), this is the transmission side gear (19).
Since the spring (50) that urges to the occlusal side is provided, when the sliding operation to the left braking side gear (26L) is stopped, the left side gear (21L) is moved to the left braking side by the urging force of the spring (50). It separates from the gear (26L) and engages with the transmission gear (19).

Further, after sliding the left and right side gears (21L) and (21R) into engagement with the left and right braking side gears (26L) and (26R), the left and right braking side gears (26L) are rotated by the main brake (42).
By braking the L) and (26R), the aircraft can be parked.

[Problems to be Solved by the Invention]

In the above-mentioned work vehicle, if the parking operation as described above is carried out immediately after the end of the turning turn by braking one traveling device, the following problems may occur.

That is, as shown in FIG. 8, for example, the left side gear (21
L) is engaged with the left braking gear (26L), and when performing parking operation immediately after turning to the right, the left side gear (21L) remains engaged with the left braking gear (26L) and the right side gear (2L
1R) is engaged with the right braking gear (26R) and the main brake (4R
2) Enter and operate.

In this case, the right braking side gear (26R) is connected to the left braking side gear (26R) via the gear (29), the transmission shaft (27) and the transmission system of the gear (29).
L), and this left braking side gear (26L) is also connected to the ground through the left side gear (21L), input gear (23L), axle (22L) and left traveling device, so right braking The side gear (26R) is not in a freely rotatable state, but is in a fixed state at a certain rotation phase. On the contrary, since the right side gear (21R) is also connected to the ground through the input gear (23R), the axle (22R) and the right traveling device, it is not in a freely rotatable state and is fixed at a certain rotation phase. It is in a state.

Therefore, when sliding the right side gear (21R) to engage with the right braking side gear (26R) in the above condition, the rotation phases of the right side gear (21R) and right braking side gear (26R) must match well. For example, the right side gear (21R) does not mesh smoothly with the right braking side gear (26R), and the right side gear (21R)
R) is forced to occlude. As a result, the surface pressure at the contact surfaces of the left and right side gears (21L), (21R) and the left and right braking side gears (26L), (26R) becomes extremely high.

Then, when the main brake (42) is turned on and operated again in the above-described state and the main brake (42) is turned off again to restart the vehicle, the left and right side gears (21L), (21L), (21L) are driven by the biasing force of the spring (50).
Even when trying to return R) to the occlusal side of the transmission side gear (19), the spring (50) can overcome the frictional force at this contact surface due to the high surface pressure at the contact surface. The left and right side gears (21L) and (21R) cannot be separated from the left and right braking side gears (26L) and (26R). Therefore, even if an attempt is made to move forward in this state, the transmission-side gear (19) simply idles and the vehicle cannot move forward.

Here, the present invention has an object to prevent a state in which the vehicle cannot move forward when the vehicle restarts as described above.

[Means for Solving the Problems]

A feature of the present invention is that the work vehicle as described above is configured as follows. That is, one end of the inner wire of the release wire is connected to one of the pair of operating parts that slides each of the side gears, and one end of the outer wire of the release wire is connected to the other of the operating parts, The inner wire is connected so that the other end of the inner wire is connected to the braking operation part of the main brake, and both operation parts are operated with each other until the both side gears mesh with the both braking side gears when the main brake is engaged. Is operated so as to pull toward the braking operation part side, and a spring that urges both operation parts toward each other on the transmission side gear meshing side is provided with a spring that biases one side gear to the braking side gear while the other side gear is engaged. Is located over both operating parts in a state in which the urging force acts from the moment when the gear starts to separate from the transmission side gear, and the action and effect are It is as of.

[Work]

As shown in FIG. 1, for example, with the left side gear (21L) in mesh with the left braking side gear (26L) and the right side gear (21R) in mesh with the transmission side gear (19), the main brake is applied to the entry side. , The inner wire (45b) is pulled to the left on the paper surface, and the right side gear (21R) is separated from the transmission side gear (19) via the right operation section (46R), and the right braking side gear (19R) is released. 2
Move to 6R) side.

In this state, both operation portion (46R), flexibility of the spring (49) which is bridged over the (46L) (A _1), (A ₂₎ (4
(See the figure) has already disappeared, and the urging force of the spring (49) is gradually strengthened. This allows the left side gear (21
In L), a spring (50) that biases the transmission gear (19) side (which was originally provided), and both operation parts (46R), (46L)
The urging force of both springs (49) installed on the left side gear (21L) is left braking by the strong urging force of both springs (49) and (50), as shown in FIG. Move away from the side gear (26L).

After that, when the inner wire (45b) is further pulled and operated, the right side gear (21R) meshes with the right braking side gear (26R) via the right operation portion (46R) as shown in FIG. The outer wire (45a) is moved to the right side of the drawing, and the left operation part (46L) is moved.
Via the left side gear (21L) to the left braking side gear (26L
L) occlusal operation. Then, in the state shown in FIG. 3, the main brake is turned on.

In this way, once the side gear that has been engaged with the braking side gear after the airframe is stopped is removed from the braking side gear (state in FIG. 2), the transmission shaft (27) in FIG. 8 and the left and right gears ( 29), (29) and left and right braking gears (26L), (26R)
Although it is in a small range, it is in a state where it can rotate freely (backlash between each gear, etc.).

Therefore, from this state, left and right side gears (21L), (21R)
If the left and right braking side gears (26L) and (26R) are engaged (states of FIG. 2 to FIG. 3), the left and right braking sides should match so that the rotation phases of both do not match. Gears (26L) and (26R) rotate slightly. This allows
The surface pressure generated on the contact surfaces of the gear teeth of both gears when they are engaged is
It will be relatively small. Therefore, when the main brake is turned off, the left and right side gears (21L) and (21R) are easily separated from the left and right braking side gears (26L) and (26R) by the spring (50) shown in FIG. ).

Also, as shown in FIG. 4, left and right side gears (21L), (21L)
(R) meshes with the transmission side gear (19), and during normal straight traveling, the springs (49) installed on both operating parts (46R) and (46L) are flexible (A ₁ ) and (A ₂ ). Is occurring. Therefore,
Left and right side gears (21L), (2
When one of the 1R) is engaged with the left and right braking gears (26L) and (26R) (see Fig. 1), the accommodation (A) of the spring (49) installed on both operating parts (46R) and (46L) Only ₁ ) and (A ₂ ) disappear, and the resistance from this spring (49) does not act.

〔The invention's effect〕

As described above, even if the main brake is operated immediately after turning to the ground, the side gear easily separates from the braking gear when the vehicle restarts, and the side gear meshes with the transmission gear when the vehicle restarts. The number of situations where the vehicle could not move away from the vehicle and could not move forward was reduced, and the running performance of the work vehicle was improved.

Then, if the spring (which corresponds to the spring (50) in FIG. 4) for urging the side gear to the transmission side gear side is simply strengthened, when the side gear is slid to the braking side gear side during normal turning, It requires a large operating force to overcome the spring. However, in the present invention, the springs (spring (49) in FIG. 4) installed on both operation parts during a normal turning operation.
Equivalent to) does not work as a resistance, so the sliding operation of the side gear is normal and the operation is not particularly heavy.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 8 shows a structure inside a transmission case (8) of a traveling system of a combine, which is one of the work vehicles, in which power from an engine (not shown) has a belt transmission mechanism (not shown) equipped with a tension clutch. ) Is transmitted to the input pulley (2) of the hydrostatic stepless transmission (1) and the power from the output shaft (3) of the hydrostatic stepless transmission (1) is transmitted to the first transmission shaft. It is transmitted from (4) through the one-way clutch (5) and the output pulley (7) to the reaper (6) shown in FIG.

The power from the first transmission shaft (4) is transmitted to the second transmission shaft (11) via the first gear (9) and the second gear (10). A first high speed gear (12) is fitted to the second transmission shaft (11) so as to be relatively rotatable, and a shift gear (14) is slidably fitted to have a spline structure.

On the other hand, the second high speed gear (16) is attached to the third transmission shaft (15).
And the low speed gear (17) is fixed, the first high speed gear (12) meshes with the second high speed gear (16), and the second transmission shaft (1
A medium speed gear (18) is fixed to 5).

With the above structure, the shift gear (14) is slid to operate the first high speed gear (12), the medium speed gear (18), and the low speed gear (17).
The power can be shifted to three stages of high, medium and low by engaging with the gear. This power is transmitted to the transmission side gear (19) which meshes with the medium speed gear (18).

The right side gear (21R) and the left side gear (21L) are relatively rotatably fitted onto the support shaft (20) that supports the transmission side gear (19), and the left and right axles (22L) and (22R) are Input gears (23R), (23L) are left and right side gears (21L),
(21R) is constantly biting. This allows
Sliding the right or left side gears (21R), (21L) to engage / separate with the transmission side gear (19) to transmit power to the drive sprocket (24a) of the crawler traveling device (24) shown in FIG. The side clutches (25R) and (25L) are formed between the transmission side gear (19) and the left and right side gears (21L) and (21R). Then, springs (50) are provided to separate the left and right side gears (21L) and (21R) from left and right braking side gears (26L) and (26R), which will be described later, and urge them toward the transmission side gear (19).

Next, the structure for braking one axle (22R) or (22L) will be described in detail. As shown in the figure, the support axle (20)
The right braking side gear (26R) and the left braking side gear (26L) are rotatably supported by the bearing, and the pair of third gears (29) fixed to the fourth transmission shaft (27) is right braking. It meshes with the side gear (26R) and the left braking side gear (26L).
A multi-plate hydraulically operated side brake (28) is provided at one end of the fourth transmission shaft (27) to separate the right side gear (21R) or the left side gear (21L) from the transmission side gear (19). Right braking side gear (26R) or left braking side gear (26R
One axle (22R) or (22L) by engaging the side brake (28) and operating it while engaging with (L)
Can be braked. As a result, a turning turn can be performed.

Next, the structure for reversing one of the axles (22R) or (22L) will be described in detail. As shown in the same figure, a fourth gear that meshes with the second high speed gear (16) of the third transmission shaft (15) ( 62)
Is externally fitted to the fourth transmission shaft (27) so as to be relatively rotatable, and a hydraulic clutch (30) is provided between the fourth gear (62) and the fourth transmission shaft (27). As a result, when the right side gear (21R) or the left side gear (21L) is engaged with the right braking side gear (26R) or the left braking side gear (26L) as described above, when the hydraulic clutch (30) is engaged and operated. Second
The power from the high speed gear (16) is transmitted in reverse to the axle (22R) or (22L) after being decelerated to 1/2. As a result, a super turning turn can be performed.

Next, the hydraulic oil supply structure for the hydraulic cylinders (31R), (31L), which slides the left and right side gears (21L), (21R), the side brake (28), and the hydraulic clutch (30) will be described in detail. As shown in FIG. 7, the hydraulic oil from the pump (32) passes through the first switching valve (33) and the left and right side gears (21
L) and (21R) are supplied to the hydraulic cylinders (31R) and (31L), and an oil passage (34) from the side surfaces of the hydraulic cylinders (31R) and (31L) is connected to the side brake (28) and the hydraulic clutch ( The variable pressure relief valve (36) for the side brake (28) and the hydraulic clutch (30) is connected to the second switching valve (35) for the hydraulic brake (30). The relief valve (61) keeps the pressure of the entire hydraulic circuit at a safe allowable pressure.

Next, the operation of the first switching valve (33), the second switching valve (35) and the variable relief valve (36) will be described in detail. As shown in FIG. 7, an operation lever (39) which can be operated in the front, rear, left and right directions, a first switching valve (33), a second switching valve (35) and a variable relief valve (36).
Are mechanically linked to each other. For example, when the operation lever (39) is operated from the neutral position (N) to the right first turning position (R ₁ ) or the first turning position (L ₁ ), the first switching valve (33) ) Is operated to operate the hydraulic gear (31R) or (31L) via the right or left operating section (46R), (46L), and the transmission side gear (1
Right or left side gear (21R), (21
L) is operated away from the transmission side gear (19) and meshes with the right or left braking side gears (26R), (26L).

In this case, the variable relief valve (36) is in the fully opened state, and both the side brake (28) and the hydraulic clutch (30) are in the disengaged state, so the right or left axle (22R), (2R)
2L) transmission is cut off (side clutch (25R)
Or (25L cut state), the aircraft makes a gentle turn to the right or left. The sequence valve (47) provided in the oil passage (34) is a right or left side gear (21R), (21L).
Is to secure the pressure required for the hydraulic cylinders (31R) and (31L) to completely engage the right or left braking side gears (26R) and (26L).

Next, the operation part (46L) for the left and right side gears (21L), (21R)
R) and (46L) will be described in detail. As shown in FIG. 5 and FIG. 6, a pair of support shafts (38R) and (38L) are rotatably supported on the front surface of the mission case (8), and are fixed at the inner ends thereof into a forked shape. Arms (40R) and (40L) are engaged with the right and left side gears (21R) and (21L), respectively. The L-shaped operation arms (41R) and (41L) are fixed to the outer ends of the support shafts (38R) and (38L), and the lower ends of the operation arms (41R) and (41L) are hydraulically operated. By pushing down the cylinders (31R) and (31L), the right or lower side gears (21R) and (21L) are moved to the right or left braking side gear (26
It is configured to be slid to the R) and (26L) sides.

Next, move the operating lever (39) to the right or left first turning position (R ₁ ),
When operating from (L ₁ ) to the right or left second turning position (R ₂ ), (L ₂ ), the right or left side gear (21R), (21L) moves to the right or left braking side gear (26R), (26L) and the second switching valve (35) is operated to supply hydraulic fluid to the side brake (28), the variable relief valve (36) is gradually closed from the fully open state. It will be operated. As a result, the side brake (28) starts to operate and the right or left axle (22
R) and (22L) are gradually braked, and the aircraft makes a right turn or left turn. Then, the braking force of the side brake (28) is maximized at the right or left second turning position (R ₂ ) or (L ₂ ) of the operating lever (39).

Next, the third pivot position right or left operating lever (39) (R _3), in the state as described above and operated to (L _3), the second
The switching valve (35) is switched to the hydraulic oil supply side to the hydraulic clutch (30). As a result, the side brake (28) is disengaged, the hydraulic clutch (30) is engaged, and the right or left axles (22R), (22L) are reversely driven, and the aircraft is superposed to the right or left. Turn around and go.

Further, the third switching valve (37) for the hydraulic cylinder (60) for raising and lowering the mowing section (6) and the operating lever (39) are mechanically linked. Thus, the reaper (6) can be moved up and down by operating the operation lever (39) to the ascending position or the descending position (upward or backward of the paper surface).

Next, the operation structure of the main brake (42) will be described in detail.
As shown in FIG. 8, a main brake (42) is provided at the other end of the fourth transmission shaft (27), and as shown in FIG. 4, the main brake (42) and the brake pedal (43). (Corresponding to a braking operation unit) is linked via a link (44). Then, in the operation portions (46R) and (46L) for the left and right side gears (21L) and (21R), the left operation arm (41
The outer wire (4) of the release wire (45)
5a) is connected at one end, and the bracket (4) is attached to one end of the inner wire (45b) of this release wire (45).
8) is attached and the long hole (48) of this bracket (48)
The pin (41Ra) of the right operation arm (41R) is engaged in a).

Then, the inner wire (45) of the release wire (45)
The other end of b) is connected to the brake pedal (43).
Further, as shown in FIG. 4, both operation arms (41R), (41R)
A spring (49) for urging the left and right side gears (21L) and (21R) toward the occlusal side of the third gear (19) is provided over the pins (51R) and (51L) fixed to L). In this case, the fourth
Left and right side gears (21L), (2
In the straight traveling state in which 1R) is engaged with the transmission side gear (19), the accommodation (A ₁ ) and (A ₂ ) are generated between the spring (49) and both pins (51R) and (51L). is doing. Also, the fifth
As shown in Fig. 4 and Fig. 4, the heads (51Ra), (51La) of the pins (51R), (51L) are oval-shaped, and the spring (49) is bent to bend the head ( 51Ra) and (51La) along the spring (49) to the pin (51R), (51R)
L) can be easily attached and detached.

With the above structure, even if the left side gear (21L) is engaged with the left braking side gear (26L) by the hydraulic cylinder (31L) and the operating portion (46L) to turn to the left from the straight traveling state shown in FIG. 4, As shown in Fig. 1, the accommodation of the spring (49) (A ₁ ),
Only (A ₂ ) disappears, and the resistance from the spring (49) does not work for the sliding operation of the left side gear (21L). This is the same when sliding the right side gear (21R). Also, the left and right side gears (21
Release wire (45) when sliding L) and (21R)
In the above, the brake pedal (43) is not operated but the accommodation effect of the elongated hole (48a) disappears.

Next, a case where the brake pedal (43) is depressed at the end of turning will be described in detail. For example, as shown in FIG.
The left side gear (21L) is engaged with the left braking side gear (26L) and the right side gear (21R) is engaged with the transmission side gear (19). It is assumed that the hydraulic continuously variable transmission (1) is temporarily stopped by performing a stop operation. In this case, the operation lever (39) is returned to the neutral position (N) and the brake pedal (43) is depressed to secure the safety during stop and restart. Fix it with 52).

When the operation lever (39) is returned to the neutral position (N) in this way, the supply of hydraulic oil to the side brake (28) and the hydraulic clutch (30) is cut off and both are disengaged, and both hydraulic cylinders ( 31R) and (31L) contract upward,
Although the transmission shaft (27) is within a small range, it can freely rotate. Then, when the brake pedal (43) is stepped on, the left side gear (21L) once separates from the left braking side gear (26L) due to the action of the release wire (45), as described in the item of [Operation]. (See Fig. 2)
The left and right side gears (21L) and (21R) again engage with the left and right braking side gears (26L) and (26R) (see FIG. 3), and the main brake (42) is turned on.

After that, when the brake pedal (43) is operated to be restarted, the urging force of the spring (49) installed over the operation arms (41R) and (41L), and the left and right side gears (21).
The left and right side gears (21L) and (21R) are separated from the left and right braking side gears (26L) and (26R) by the urging force of the spring (50) provided to the left and right (L) and (21R), and the spring (50) The left and right side gears (21L) and (21R) are engaged with the transmission side gear (19) by the urging force of.

The present invention is not limited to those equipped with a crawler traveling device,
It can also be applied to wheeled work vehicles such as 8-wheeled vehicles and 6-wheeled vehicles.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a work vehicle according to the present invention, and FIG. 1 is a front view around the left and right side gears and an operating portion showing a left turning state in which a left side gear is engaged with a left braking side gear, and FIG. The front view showing the state in which the brake pedal is started to be depressed from the state shown in the figure, the front view showing the state in which the brake pedal is further depressed from the state shown in FIG. 2, and the left and right side gears are the transmission sides in FIG. FIG. 5 is a front view of the left and right side gears and the vicinity of the operating portion in a straight state in which the gears are engaged, FIG. 5 is a perspective view of the operating portion for the left and right side gears, FIG. 6 is a front view of the operating portion and the hydraulic cylinder, and FIG. Fig. 8 is a hydraulic circuit diagram of the control valve, Fig. 8 is a vertical sectional front view of the mission case, and Fig. 9 is a side view of the front portion of the combine. (19) …… Transmission side gear, (21R), (21L) …… Side gear, (24) …… Traveling device, (26R), (26L) …… Braking side gear, (28) …… Side brake, ( 42) …… Main brake, (43) …… Brake operation part, (45) …… Release wire, (45a) …… Release wire outer wire, (4
5b) …… Inner wire of release wire, (46),
(46L) …… Operation part, (49), (50) …… Spring,
(A ₁ ), (A ₂ ) ... interchangeable.

Claims (1)

[Claims] 1. A pair of side gears (21R), (21L) for transmitting power to a pair of left and right traveling devices (24), (24) are respectively provided at an engagement position with a transmission side gear (19) and a side brake (21). 28) a pair of left and right braking gears (26R), (26L)
A spring (50) that slidably supports the gears and the side gears (21R) and (21L) to urge the side gears (21R) and (21L) to the transmission side gear (19), and both braking side gears. (26
A work vehicle including a main brake (42) for braking a transmission system that interlocks and couples R) and (26L), and a pair of operating portions that slides each of the side gears (21R) and (21L). Release wire (45) to one of (46R) and (46L)
Of the inner wire (45b) of the relays wire (45) is connected to the other of the operation portions (46R) and (46L). The other end of (45b) is connected to the braking operation part (43) of the main brake (42), and both side gears (21R) and (21L) are connected with the operation of entering the main brake (42).
Pull the inner wire (45b) toward the braking operation part (43) so that both operation parts (46R) and (46L) are operated until they mesh with both braking side gears (26R) and (26L). And a spring (49) for urging the operating parts (46R) and (46L) to attract each other toward the transmission side gear (19) and the occlusal side, and one side gear (21R) and (21L). When the other side gears (21R) and (21L) start to separate from the transmission side gear (19) while the gear meshes with the braking side gears (26R) and (26L), the accommodation (A ₁ ), ( A work vehicle that is installed over both operating parts (46R) and (46L) with A ₂ ).