JPH03153478A - Farm working vehicle - Google Patents

Abstract

PURPOSE:To enhance the traveling performance of a far working vehicle by supporting a pair of side gears, transmitting power to a symmetrical pair of traveling devices, free of side motion ranging from an engagement position with the transmission side gear to that with a symmetrical pair of braking side gears equipped with the side brake. CONSTITUTION:Power out of an engine is shifted by way of a continuously variable transmission 1 and a transmission case 8 and transmitted to a transmitted side gear 19. Symmetrical side gears 21L, 21R are externally fitted in a support shaft 20 supporting this transmitted side gear 10 free of relative rotation, and engaging them with input gears 23L, 23R of symmetrical axles 22L, 22R at all times. In addition, symmetrical braking side gears 26L, 26R are supported on the support shaft 20 free of relative rotation, while one side of these side gears 21L, 21R is engaged with one side of the side gears 21L, 21R, and a side brake 28 is operated to ON, through which braking is imposed on one side of these axles 22L, 22R, letting them perform their ground turning. In this connection, the side brake 28 is controlled so as to reduce the braking force with braking operation of a main brake 42.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a traveling transmission system in a working vehicle such as a combine harvester.

[Conventional technology]

Some combine harvesters, which are one type of work vehicle, are equipped with a pair of left and right crawler-type traveling devices, and are configured to apply braking to one of the traveling devices to make a pivot turn. Its structure is as follows.

In other words, as shown in Figure 5, the left and right traveling devices (not shown)
Left and right side gears (21L) that transmit power to (21
When both of R) are engaged with the transmission side gear (19), power is input to both traveling devices to the input gear (23R).

(23L), axles (22R), and (22L) in a normal rotation state, and the aircraft moves straight. Then, for example, slide the left side gear (21L) to engage the left braking side gear (26L), and then engage the left braking side gear (26L).
When the left handbrake (28) is applied and operated, the left traveling gear is braked and the aircraft turns to the left. Also, since the left side gear (21L) is provided with a spring (50) that biases it toward the engagement side of the transmission side gear (19), when the sliding operation toward the left braking side gear (26L) is stopped, The biasing force of the spring (50) causes the left side gear (21L) to become the left braking side gear (26L).
The transmission side gear (19) is engaged with the transmission side gear (19).

Furthermore, slide the left and right side gears (21L) and (21,R) to shift the left and right braking side gears (26L) and (26
After the main brake (42) engages the left and right brake gears (26L) and (26R), the aircraft can be parked.

[Problem to be solved by the invention]

If the above-mentioned parking operation is performed immediately after completing a pivot turn by applying braking to one of the traveling devices in the above-mentioned work vehicle, the following problem may occur.

In other words, as shown in Fig. 5, for example, the left side gear (2
When performing a parking operation immediately after turning with the left braking side gear (26L) engaged with the left side gear (21L),
) remains engaged with the left braking gear (26L), and the right side gear (21R) is engaged with the right braking gear (26R) to engage and operate the main brake (42).

In this case, the right braking side gear (26R) is the gear (29).

Since it is connected to the handbrake (28) via the transmission shaft (27), the right braking side gear (26R) is not in a state where it can freely rotate due to the braking action of this handbrake (28), but at a certain rotational phase. It is in a fixed state. Conversely, the right side gear (21R) is the input gear (23R).
), is connected to the ground via the axle (22R) and the right traveling device, so it is not in a state where it can rotate freely, but is in a state where it is almost fixed at a certain rotational phase.

Therefore, when sliding the right side gear (2JR) to engage the right braking side gear (26R) in the above condition,
If the rotational phases of the right side gear (21R) and the right braking side gear (26R) do not match well, the right side gear (21R) and the right braking side gear (26R)
1R) does not mesh smoothly with the right braking side gear (26R), and the right side gear (21R) is forcibly engaged. As a result, the left and right side gears (21L),
<21R) and left and right braking side gears (26L), (26R)
The surface pressure on the contact surfaces of the gear teeth becomes extremely high.

When the main brake (42) is engaged and operated again in the above-mentioned state and the main brake (42) is disengaged to restart the vehicle, the left and right side gears (21L) are shifted by the biasing force of the spring (50).
), Even if an attempt is made to return (21R) to the occlusal side of the transmission gear (19), the spring (50) overcomes the frictional force on the contact surface due to the high surface pressure on the contact surface of the gear teeth. The left and right side gears (21L), (
21R) is the left and right braking side gear (26L).

(26R) becomes impossible to leave. Therefore, even if you try to move forward in this state, the transmission side gear (
19) will just spin idly and you will be unable to move forward.

Here, the present invention aims to prevent the situation where the vehicle cannot move forward when restarting, as described above.

[Means to solve the problem]

The feature of the present invention is that the above-mentioned work vehicle is constructed as follows. In other words, each of the pair of side gears that transmit power to the pair of left and right traveling devices can be slid freely between the engagement position with the transmission gear and the engagement position with the pair of left and right braking gears equipped with hand brakes. A main brake is provided to apply braking to a transmission system that is supported by the main brake and interlocks the two braking side gears, and a control means that reduces the braking force of the handbrake as the main brake is operated to the braking side. It is in the preparation, and its action/
The effects are as follows.

[For production]

For example, as shown in Fig. 5, the left side gear (21L) engages with the left braking side gear (26L) and the hand brake (2
8) applies braking to the left braking side gear (26L),
In addition, in a state where the right side gear (21R) is engaged with the transmission side gear (19), the main brake (42) is operated to the braking side while sliding the right side gear (21R) to the right braking side gear (26R). As this progresses, the braking force of the handbrake (28) is reduced.

When this condition occurs, the left braking side gear (26
L), the gear (29), the transmission shaft (27), and the right braking side gear (26R) are fixed by the handbrake (28), but are now able to rotate slightly.

Therefore, the right side gear (21R) is the right braking side gear (26
R), even if the rotational phases of both do not match well, the right side gear (21R) will engage the right braking side gear (21R).
26R), both rotate slightly against each other against resistance from the handbrake and the ground. As a result, the right side gear (21R) becomes the right braking side gear (26R).
), the surface pressure generated on the contact surfaces of the gear teeth of both gears is relatively small. When the right braking gear (26R) rotates slightly as described above, the left braking gear (26L) also rotates slightly or becomes rotatable in conjunction with this. This allows the left side gear (
21L) and the gear teeth of the left braking side gear (26L) are also relatively small.

Therefore, when the main brake (42) is turned off after this, the left and right side gears (
21L), (21R) are the left and right braking side gears (26L).

It easily separates from (26R) and engages with the transmission gear (19).

〔Effect of the invention〕

As mentioned above, when the main brake is operated to the braking side,
By increasing the margin for both braking side gears to rotate, there will be fewer situations where the side gear cannot move away from the braking side gear and the vehicle cannot move forward when restarting.
We were able to improve the driving performance of the work vehicle.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figure 5 shows the structure inside the transmission case (8) of the traveling system of a combine harvester, which is one of the working vehicles.
The power from the hydrostatic continuously variable transmission (not shown) is transmitted through a belt transmission mechanism (not shown) equipped with a tension clutch.
1), and the power from the output horn shaft (3) of the hydrostatic continuously variable transmission (1) is transmitted from the first transmission shaft (4) to the one-way clutch (5) and the output. It is transmitted to the reaping section (6) shown in FIG. 6 via the pulley (7).

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 (IO), and the second transmission shaft (11) A first high-speed gear (12) is fitted onto the outside so as to be relatively rotatable, and a shift gear (14) is fitted onto the outside so as to be slidable with a spline structure.

On the other hand, the second high-speed gear (1
6) and low speed gear (17) are fixed, and the first high speed gear (
12) is engaged with the second high-speed gear (16), and the third
A medium speed gear (18) is fixed to the transmission shaft (15).

With the above structure, by sliding the shift gear (14) and engaging it with the first high speed gear (12), medium speed gear (18), and low speed gear (17), the power can be shifted into three stages: high, medium and low. This power is transmitted to the transmission side gear (19) that meshes with the medium speed gear (18).

The support shaft (20) that supports the transmission side gear (19) includes a right side gear (21R) and a left side gear (21L).
is fitted on the outside so that it can rotate freely, and the left and right axles (22
L), (22R) input gear (23R), (23L
) are always engaged with the left and right side gears (21L) and (21R). As a result, the right or left side gears (21R) and (21L) are slid to engage and separate from the transmission gear (19), and the drive sprocket (24a) of the crawler traveling device (24) shown in FIG. On the other hand, it performs important operations in power transmission, and the transmission side gear (1
9) and the left and right side gears (21L), (21R) constitute side clutches (25R), (25L). And left and right side gears (21L).

(21R) is the left and right braking side gear (26L), (
26R) and biased toward the transmission gear (19).

Next, the structure for applying braking to one axle (22R) or (22L) will be explained in detail.As shown in the figure, the right braking side gear (28R) and the left braking side gear (28R) are attached to the support shaft (20).
26L) is supported by a relatively rotatable bearing, and
A pair of third gears (29) fixed to the fourth transmission shaft (27)
) is the right braking side gear (26R) and the left braking side gear (26L).
). A multi-plate hydraulically operated handbrake (28) is provided at one end of the fourth transmission shaft (27), and is connected to either the right side gear (21R) or the left side gear (21R).
21L) is separated from the transmission gear (19) and engaged with the right braking gear (26R) or the left braking gear (26L), and the handbrake (28) is applied to move one axle (22R) or (22L) can be braked. This allows a pivot turn.

Next, to explain in detail the structure for reversing one axle (22R) or (22L), as shown in the same figure, the fourth gear ( 62) is fitted onto the fourth transmission shaft (27) so as to be relatively rotatable, and the fourth gear (62) and the fourth transmission shaft (27)
A hydraulic clutch (30) is provided between the two. As a result, the right side gear (21R) or the left side gear (21R)
1L) is engaged with the right braking side gear (26R) or the left braking side gear (26L) as described above, and when the hydraulic clutch (30) is engaged and operated, the power from the second high speed gear (16) is reversed. state, and the axle is decelerated to 1/2 (
22R) or (22L). This allows you to perform a super solid turn.

Next, the hydraulic cylinders (31R), (31I,
The structure for supplying hydraulic oil to the handbrake (28) and the hydraulic clutch (30) will be described in detail. As shown in Figure 1, hydraulic oil from the pump (32) is supplied to the hydraulic cylinders (31R) and (31L) for the left and right side gears (21L) and (21R) via the first switching valve (33). At the same time, the oil passage (34) from the side of the hydraulic cylinders (31R) and (31L) is connected to the second switching valve (35) for the handbrake (28) and the hydraulic clutch (30), and the oil passage (34) There is a variable relief valve (36) for the handbrake (28) and hydraulic clutch (30).
) are connected. Further, the relief valve (61) maintains the pressure of the entire hydraulic circuit at a safe allowable pressure.

Next, the operations 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. 1, an operating lever (39) that can be operated forward, backward, left, and right is mechanically linked to a first switching valve (33), a second switching valve (35), and a variable relief valve (36). , for example, move the operating lever (39) from the neutral position (N) to the first right turning position (
R1) or the first left turning position (L,), the first
Only the switching valve (33) is operated and the hydraulic cylinder (31R
) or (31L), the right or left operation part (46R)
, (46L), and the right or left side gear (21R) meshing with the transmission side gear (19).

(21L) separates from the transmission gear (19) and engages with the right or left braking gear (26R), (26L).

In this case, the variable relief valve (36) is in a fully open state,
Since both the handbrake (28) and hydraulic clutch (30) are in the disengaged state, the right or left axle (22)
R), (22L) is cut off (side clutch (25R) or (25L) is disengaged),
The aircraft makes a slow turn to the right or left.

In addition, a sequence valve (47) provided in the oil passage (34)
) is the pressure required for the right or left side gear (21R), (21L) to fully engage the right or left braking side gear (26R), (26L), the hydraulic cylinder (31R),
(31L).

Next, the operation parts (46R) and (46L) for the left and right side gears (21L) and (21R) will be described in detail. Second
．． As shown in Figure 3.4, a pair of support shafts (38R) and (38L) are rotatably supported on the front of the mission case (8), and a bifurcated arm ( 40R) and 40L) are the right and left side gears (
21R, (engages with 21L. And the support shaft (
L-shaped operating arms (41R, (41L) are fixed to the outer ends of 38R, (38L), and the lower ends of these operating arms (4R), (4L) are connected to hydraulic cylinders (38L).
1R).

(By pushing down 31L, the right or left side gear (21R), (21L) will shift to the right or left braking side gear (21R).
26R).

It is configured to be slid to the (26L) side.

Next, move the operating lever (39) to the right or left first turning position (R+
), (L+) to the right or left second turning position (R2), (L
,) to operate the right or left side gear (21R).
.

(21L) is the right or left braking side gear (26R), (26
L) and the second switching valve (35) is operated to supply hydraulic oil to the handbrake (28), the variable relief valve (36) is gradually operated from the fully open state to the closed side. I'm going to be done. As a result, the handbrake (28) begins to act, and the right or left axle (22R) or (22L) is gradually braked, and the aircraft turns to the right or left. Then, the second right or left of the operating lever (39)
The braking force of the handbrake (28) is maximum at the turning positions (R2) and (Lm).

Next, move the operating lever (39) to the right or left third rotation position (R
3), (L:l), the second switching valve (35) is switched to the hydraulic oil supply side to the hydraulic clutch (30) in the state described above. This allows the handbrake (
28) is in the disengaged state, and the hydraulic clutch (30)
is engaged and the right or left axle (22R), (22
L) is driven in reverse, and the aircraft makes a sharp turn to the right or left.

Further, the third switching valve (37) for the hydraulic cylinder (60) for raising and lowering the reaping part (6) and the operating lever (39) are mechanically linked. This allows the operating lever (39)
to the raised position or lowered position (toward the top of the page or the back of the page)
By operating the reaping section (6), the reaping section (6) can be raised and lowered.

Next, the operating structure of the main brake (42) will be described in detail. As shown in FIG. 5, a main brake (42) is provided at the other end of the fourth transmission shaft (27), and as shown in FIG. 2, this main brake (42) and a brake pedal (43)
are connected via a link (44). And left and right side gears (21L).

In the operation parts (46R) and (46L) for (21R), one end of the outer wire (45a) of the release wire (45) is connected to the upper end of the left operation arm (41L), and the release wire ( A bracket (48) is attached to one end of the inner wire (45b) of the bracket (45), and the pin (41Ra) of the right operating arm (41R) is engaged in the elongated hole (48a) of the bracket (48). The other end of the inner wire (45b) of the release wire (45) is connected to the brake pedal (43).

Therefore, when the brake pedal (43) is depressed, the inner wire (45b) is pulled toward the brake pedal (43), and the left and right operating arms (41, R) are operated.

(41L) is the left and right side gear (21L) which is operated by swinging.

(2), R) is the left and right braking side gear (26L), (26R)
), the main brake (42) is engaged and operated to apply braking to the left and right crawler traveling devices (24).

The vehicle can be parked by fixing the brake pedal (43) at the depressed position with the hook member (52).

Next, a case in which the brake pedal (43) is depressed at the end of a pivot turn will be described in detail. For example, Figures 5 and 1
As shown in the figure, the left side gear (21L) is engaged with the left braking gear (26L), and the right side gear (21R) is engaged with the transmission gear (19). Assume that at the end of the second left turning position (L2), the hydrostatic continuously variable transmission (1) is stopped and temporarily stopped.

In this case, in order to ensure safety when stopping and restarting, return the operating lever (39) to the neutral position (N), depress the brake pedal (43), and secure it with the hook member (52). (When the operating lever (39) is returned to the neutral position (N), the variable relief valve (36) becomes fully open and the handbrake (28) is turned off).

However, if the brake pedal (43) is pressed while the control lever (39) remains at the second left turning position (L2) without returning to the neutral position (N), the right side gear (21R) in Fig. 5 When engaging the right braking side gear (26R), as mentioned in the item [Problems to be Solved by the Invention] above, the surface pressure on the contact surface of each gear tooth increases, causing the left and right side gear (21L) to engage.

(21R) or left and right braking side gear (26L), (26R)
It will be difficult to pull it out.

As shown in Fig. 1, as a configuration to prevent the above situation,
A switching valve (49) is provided in the oil path from the second switching valve (35) to the handbrake (28). This switching valve (49
) is the first position (49a) that communicates the handbrake (28) and the tank (51), and the handbrake (28)
and a second position (49b) that blocks off the tank (51) and the second position (49b) by a spring (49c).
biased toward the side. And the brake pedal (43)
When you step on the button, the switching valve (49) moves to the first position (49a).
The brake pedal (43) and the switching valve (49) are linked so that the brake pedal (43) is operated to the side.

As a result, when the main brake (42) is applied, the side brake (28) is turned off, and the left and right side gears (21L) and (21R) and the left and right braking side gears (26L) are turned off.
.

The surface pressure on the contact surface of the (26R) gear teeth does not increase (see the [Function] section above).

Therefore, when the operating lever (39) is returned to the neutral position (N) and the brake pedal (43) is operated again from the above-mentioned state, the main brake (42) is turned off and the switching valve (49)
is returned to the second position (49b), and the spring (50)
The biasing force causes the left and right side gears (21L) and (21R) to slide toward the transmission gear (19) and engage with it.

[Another example]

As shown in Fig. 7, an on-off valve (13) (
The brake pedal (43) and the on-off valve (13) are provided with a spring (13a) biased toward the closing side so that when the brake pedal (43) is depressed, the on-off valve (13) is operated on the open side. It is also possible to have a structure in which these are linked.

In the embodiment described above, the handbrake (28) was completely turned off when the brake pedal (43) was pressed, but the brake pedal (43) could be pressed without providing the cut-off valve (49) and the on-off valve (13). At the same time, the variable relief valve (36) shown in Fig.
8) A structure that reduces the braking force may also be used.

The present invention is applicable not only to those equipped with a crawler traveling device (24) but also to wheeled work vehicles such as eight-wheeled vehicles and six-wheeled vehicles.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the work vehicle according to the present invention, in which Fig. 1 is a hydraulic circuit diagram of a hydraulic cylinder and each control valve, Fig. 2 is a front view of left and right side gears and operating parts, etc. in a straight-ahead state, and Fig. 3 is a perspective view of the operating section for the left and right side gears, FIG. 4 is a front view of the operating section and hydraulic cylinder for the left and right side gears, FIG. 5 is a longitudinal sectional front view of the transmission case, and FIG. 6 is a side view of the front half of the combine harvester. , FIG. 7 is an oil passage circuit diagram in another embodiment. (19)...Transmission side gear, (2]R), (2
1L)...Side gear, (24)...
Traveling device, (26R), (26L)...Brake side gear, (28)...Handbrake, (42
)...Main brake. Figure 3 Ma 4

Claims (1)

[Claims] Each of a pair of side gears (21R) and (21L) that transmits power to a pair of left and right traveling devices (24) and (24),
The engagement position with the transmission side gear (19) and the handbrake (
A pair of left and right braking side gears (26R), (28) equipped with
A main brake (42) is provided that is slidably supported across the occlusal position with the main brake (42) and applies braking to a transmission system that interlocks and connects the two braking side gears (26R) and (26L). A work vehicle equipped with a control means for reducing the braking force of the handbrake (28) as the brake (42) is operated to the braking side.