JP2627816B2 - Steering device for traveling work vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a steering device for a traveling work vehicle.

<Conventional technology> Conventionally, as a steering lever of a combine or the like, a device is known in which one operating lever is swung left and right to activate a left or right side brake to steer.

In addition, in a riding traveling work vehicle such as a combine, etc., a reverse rotation shaft is provided in the transmission, and left and right friction clutches are attached to the reverse rotation shaft, and the reverse rotation shaft is used during normal running (forward rotation) of the body. A braking reaction force is obtained by operating either the left or right friction clutch in the locked state on the transmission side, and this mechanism has a switching clutch that turns the reverse shaft between the locked state and the reverse rotation state "on" and "off" Have been.

In addition, the turning side clutch is disengaged during forward running.
A mechanism is also proposed in which the friction clutch is actuated to turn in the state, or the turning side is reversely driven to make a pivot turn.

<Problems to be Solved by the Invention> However, in the above-described mechanism, the "disengagement" operation of the left and right side clutches during turning, the turning turning by one-side braking, the turning of the ground by the one-side reverse rotation, and the like are respectively performed. It is operated by another operation system, and has a disadvantage that the mechanism and operation are complicated.

<Means for Solving the Problems> An apparatus according to the present invention for solving the above-mentioned problems includes a reversing shaft for reversing left and right running parts in a transmission 3.
A switching clutch 43 for supporting the reverse rotation shaft 41 to lock the reverse rotation shaft 41 on the transmission 3 side or operating the reverse rotation transmission input to “on”, and performing “on” and “off” forward rotation power to the left and right traveling units. A side clutch is provided, and the reverse rotation shaft 41 is provided with left and right friction clutches 46, 47 by hydraulic control for braking the left and right traveling parts or transmitting and disconnecting the reverse rotation of the reverse rotation shaft 41 to the left and right traveling parts, In a mechanism in which one steering lever 79 for controlling each of the friction clutches 46 and 47 and the side clutch in association with the left or right swing is provided on the driver's seat side, the operation by the steering lever 79 is performed. In the system, by increasing the oil pressure corresponding to the amount of operation of the steering lever 79 to the left or right,
In the lock operation position of the switching clutch 43, only the braking force of the left or right friction clutch 46, 47 is increased, and in the reverse input operation position of the switching clutch 43, the braking force of the left or right friction clutch 46, 47 is reduced. A pressure proportional control valve 89 that acts in the clutch "on" direction of the reverse rotation input in addition to the rise is provided.

<Operation> The reverse rotation shaft 41 is connected and disconnected to transmit the reverse rotation driving force by the switching clutch 43 or is set in a locked state on the transmission 3 side. When the left or right friction clutches 46, 47 are engaged, when the reverse rotation shaft 41 is in the locked state, it acts as a brake for braking the forward (forward rotation) transmission system of the left or right traveling unit, and the reverse rotation shaft 41 When the reverse rotation is being performed, the brakes for forward running are applied to the traveling section on the side clutch "disengaged" side, and when the braking force is further strengthened, the brakes are sequentially turned to the braking side. The running part is reversely rotated together with the reverse rotation axis, and a super pivot turn is performed.

The above operation is performed by swinging one steering lever 79 left and right, thereby operating the pressure proportional control valve 89 in accordance with the swing amount from its neutral position. The braking force of the friction clutch 46 or 47 is increased in proportion to the pressure applied from the operating system. At this time, the steering lever 79
The left or right side clutch is in the "disengaged" state at the first position in which the left or right swings from the neutral position, and the subsequent swinging is performed in accordance with the swing operation charge by the braking force of the friction clutch 46 or 47. Are sequentially increased.

<Example> An example will be described in detail below with reference to the drawings. FIG. 2 shows a traveling power transmission device (transmission) for traveling work having a crawler traveling device such as a combine.
It is sectional drawing which shows the internal mechanism of No. 1.

An input shaft 5 is supported in the case 3, and an input pulley 6 is fixed to a protruding portion of the input shaft 5.

The other end of the input shaft 5 extends into a hydraulic continuously variable transmission (HST) 7 attached to the outside of the case 3, and the rotation of the input shaft 5 transmitted via the input pulley 6 is applied to the hydraulic continuously variable transmission. The speed is changed at 7 and output to the output shaft 8. The hydraulic continuously variable transmission 7 is operated by a main transmission lever to perform a speed change operation so that the speed can be continuously changed.

A gear 9 is fixed to an output shaft 8 supported in the case 3, and is connected to a gear shaft 12 via a gear 11 meshed with the gear 9.
The driving force is transmitted to the motor. A sub transmission gear 13 that rotates integrally with the gear shaft 12 is attached to the gear shaft 12 so as to be slidable in the axial direction. The sub-transmission gear 13 is composed of gears of three different diameters for three-speed shifting, and is fixed to the transmission shaft 14.
The gears of the step-variable gear 15 mesh with each other.

The medium-speed gear of the transmission gear 15 is a gear 18 fixed to the drive shaft 16.
And transmits the driving force to the drive shaft 16.

First, a forward (forward) transmission system will be described. In addition to the gear 18, a gear 17 having a smaller diameter than the gear 18 is fixed to the drive shaft 16, and a center gear 20 fixed to a center gear shaft 19 and a gear I agree.

Inner teeth 21 and 22 are formed on both left and right side surfaces of the center gear 20, and side clutch gears 23 and 24 are meshed with each other so as to be freely disengageable. The side clutch gears 23 and 24 are slidably attached to side clutch shafts 25 and 26 which are externally mounted on the center gear shaft 19 on the same axis.
By sliding left and right on 25 and 26, the engagement with the internal teeth 21 and 22 of the center gear 20 is disengaged. Output gears 27 and 28 provided on left and right axles 29 and 30 mesh with the left and right side clutch gears 23 and 24, respectively. Accordingly, the driving force of the center gear 20 is such that the left and right side clutch gears 23, 24
When engaged with 22, it is transmitted to axles 29,30. Axle 2
9 and 30 extend in the left-right direction from the case 3, and a sprocket 31 is attached to a tip end thereof, and a crawler belt 32 is wound around the sprocket 31. According to the above-described forward rotation transmission system, as shown in FIG.
Is set to the on state and the friction clutches 46 and 47 are set to the off state,
Power is transmitted in the order of the drive shaft 16, the gear 17, the center gear 20, the side clutch gears 23 and 24, the output gears 27 and 28, and the axles 29 and 30, so that the aircraft advances.

 Next, the transmission system of the reverse rotation shaft will be described.

The left and right side clutch shafts 25 and 26 reach the left and right outer sides of the case 3, and reverse rotation transmission gears 35 and 36 are fixed to protruding ends, respectively. Further, support portions 33, 34 formed of bearing bearings are provided inside the left and right reversing transmission gears 35, 36, and support the side clutch shafts 25, 26 and the center gear shaft 19 simultaneously and on the same axis. I have.

A free rotation gear 42 rotatably supported by a reverse rotation shaft 41 meshes with the gear 18 of the drive shaft 16. A switching clutch 43 is also supported on the reverse rotation shaft 41, and the switching clutch 43 is provided so as to rotate integrally with the reverse rotation shaft 41 and to be slidable in the axial direction. The switching clutch 43 is a meshing clutch. Clutch claws are provided on both sides of the switching clutch 43. Clutch claws that mesh with the clutch claws of the switching clutch 43 are provided inside the free rotation gear 42 and the case 3.

The switching clutch 43 is always engaged with the clutch pawl 44 on the free rotation gear 42 side or the clutch pawl 45 on the case 3 side.

When the switching clutch 43 is engaged with the clutch pawl 44 of the free rotation gear 42, the power of the drive shaft 16 is transmitted to the reverse rotation shaft 41 via the free rotation gear 42, and the switching clutch 43 When engaged, the rotation of the reverse rotation shaft 41 is restricted. Both ends of the reverse rotation shaft 41 reach the outside of the case 3, and input ends of friction clutches 46 and 47 are attached to both ends. The friction clutches 46 and 47 are multi-plate clutches in the device of the present embodiment, and clutch cases 50 and 51 are formed outside the friction clutches 46 and 47, respectively.
47 and the reverse transmission gears 35 and 36 are covered. Gears 48, 49 are formed on the output side of the friction clutches 46, 47, and the above-mentioned reverse rotation transmission gears 35, 36 mesh with each other.

The friction clutches 46 and 47 are actuated by pressing a pressing plate 54 fitted slidably in the axial direction at the end of the reversing shaft 41, and the pressing plate 54 is provided with a disc-shaped piston 57 via a thrust bearing 56. Are pressed from the outside. The piston 57 is fitted with a cylinder 59 formed in the clutch cases 50 and 51 at the center of the outer surface, and when the hydraulic pressure is applied to the cylinder 59, the piston 57 is
It performs 6,47 "on" operations and "off" operation by releasing the hydraulic pressure.

The piston 58 is also operated by rotating eccentric cam pins 61 and 62 inserted so as to penetrate the cylinder 59 by rotating a pin lever 63 attached to a protruding portion thereof. , 47 is used, for example, at the time of a parking brake for simultaneously operating the left and right friction clutches 46, 47 or at the time of braking during traveling.

According to the transmission system of the above-described reverse rotation shaft, the switching clutch 43 is engaged with the free rotation gear 42 side, and the side clutch gear 23,
If (24) is set to the off state and the friction clutches 46 and (47) are set to the on state, the drive shaft 16, the gear 18, the free rotation gear 42, the switching clutch 43, the reverse rotation shaft 41, the friction clutches 46 and (47), Gear 4
8, (49), reverse transmission gear 35, (36), side clutch shaft 2
5, (26), side clutch gear 23, (24), output gear 27,
(28) Power is transmitted in the order of axles 29 and (30), and the aircraft turns left or right.

Next, the operation of each part when the forward rotation operation is performed based on the transmission 1 will be described. The forward / backward movement is as described above. When the parking brake is applied, the switching clutch 43 is engaged with the clutch pawl 45 on the case 3 side to restrict the rotation of the reverse rotation shaft 41, and the left and right friction clutches are engaged.
46, 47 are in the ON state. As a result, a braking force acts on the axles 29 and 30, and the body does not move. When the switching clutch 43 is engaged with the free rotation gear 42 in the state shown in FIG.
Rotational force is applied to the drive shaft 16 in the reverse direction from the forward rotation transmission system and the reverse rotation transmission system, so that the axles 29 and 30 cannot rotate and are braked. In this case, it is desirable that the speed ratio of the forward rotation transmission system and the reverse rotation transmission system be the same, and the friction clutches 46 and 47 can be used as a parking brake, and a special parking brake structure is not required. Thereby, simplification of a mechanism, weight reduction, cost reduction, etc. can be achieved.

Next, a case of turning left is described. First,
When turning left from the forward state described above with reference to FIG. 1, as shown in FIG. 5, the left side clutch gear 23 is set to the disengaged state, and the switching clutch 43 is connected to the clutch pawl provided on the case 3 side. Engage with 45. By switching the switching clutch 43, the reverse rotation shaft 41 is brought into a stopped state. Here, since the right crawler is driven forward, the left crawler is rotated by the forward movement of the right crawler, and the body gradually turns left. When the operation amount of the operation unit is increased and the clutch lever 52 is swung and the friction clutch 46 is turned on, the left transmission system stops because the reverse rotation shaft 41 is stopped, and the left crawler stops. This allows the aircraft to make a left pivot turn around the left crawler. When turning right,
Similarly, the switching clutch 43 is engaged with the clutch pawl 45 on the case 3 side, the right side clutch gear 24 is disengaged, and the friction clutch 47 is engaged.

When the switching clutch 43 is engaged with the clutch pawl 45 on the case 3 side, the reverse rotation shaft 41 is stopped, so that only pivot turning is possible.

Next, a description will be given of a left pivot turn and a left pivot turn at the time of low-speed traveling in the case of working traveling. First, when turning left from the forward state described above with reference to FIG. The clutch gear 23 is disengaged, and the switching clutch 43 is engaged with the clutch pawl 44 provided on the free rotation gear 42 side.
To engage. By switching the switching clutch 43, the reverse rotation shaft 41 is always in the reverse rotation state.

Here, since the right crawler is driven forward, the left crawler is rotated by the forward movement of the right crawler, and the body gradually turns left. When the operation amount of the operation unit is increased and the friction clutch 46 is brought into the half clutch state, the reverse rotation
The rotation of the output gear 48 is stopped by the sliding friction with the friction plate 41, the left transmission system stops, and the left crawler stops. This allows the aircraft to make a left pivot turn around the left crawler. When the operation amount of the operation unit is further increased to bring the friction clutch 46 into the completely engaged state, the transmission system on the left side includes the reverse rotation shaft 41, the friction clutch 46, and the gear 4
8, reverse transmission gear 35, side clutch gear 23, output gear 27,
The axle 29 is arranged in this order, and the reverse power is transmitted. As a result, the left and right crawler driving directions are reversed, and the aircraft makes a super pivot turn. With the above configuration,
With the same operation amount as in the high-speed running state, it is possible to extremely easily and quickly switch from the pivot turn to the super pivot turn, thereby improving the operation performance. Therefore, it is particularly effective at the time of work traveling where fine and quick forward rotation operation is required.

Furthermore, switching from pivot turning to super turning is performed continuously due to changes in the clutch pressure of the friction clutches 46 and 47. There is an advantage that the impact load on each part of the mechanism at the time is extremely reduced.

Next, the shift operation of the sub-transmission gear 13 and the switching operation of the switching clutch 43 will be described. In the case where the switching clutch 43 is turned on to the gear 42 while the sub-transmission gear 13 is in the high-speed "on" state,
There is a risk of the aircraft turning sharply. For this reason, in the present embodiment, when the sub-transmission gear 13 is in the high-speed "on" state, the switching clutch 43 is prevented from being in the "on" state on the reverse rotation side.
A mechanism that does not cause the above-mentioned danger by using both the operation lever and the auxiliary transmission lever is adopted.

As shown in FIGS. 3 to 5, the auxiliary transmission lever 65 is provided with a mechanism for switching between a medium speed M, a high speed H, and a low speed L by swinging back and forth along a lever guide 66 provided on the body cover. None, a neutral N range is formed between the respective patterns, and this shift range 66 in the front-rear direction is provided.
On the other hand, switching regions 66b and 66c are formed in the middle-speed M region and the low-speed L region at the front and rear ends. When the operation is performed in the switching area 66a or 66c, the switching clutch 43 engages with the clutch pawl 44, and the reverse rotation shaft 41 rotates in the reverse direction.

To enable the above operation, the sub-transmission lever 65 is
As shown in FIGS. 7A and 7B, the upper lever 65a and the lower lever 65b are provided via a bracket 67 and a pin 68 which form a gate in a side view so as to be able to rotate (bend) left and right in the middle.
And the lower end of the lower lever 65b is pin 6
At 9, it is pivotally supported on the fuselage side so that it can swing back and forth.

And the upper lever 65a has a gate shape in a side view,
A front-rear guide groove 71a corresponding to the front-rear shift range 66a
The bracket 71 has a lower end pivotally supported by a pin 73 on a boss 72 fixed to the body frame side so as to be able to swing left and right. Swings right and left with.

In the vicinity of the pivotal support portion of the lower lever 65b and the bracket 71, swing arms 74 and 76 projecting in the respective swing directions and swinging together with the lower lever 65b and the bracket 71 are provided. An operating system 77, such as a wire or a rod (not shown), for operating the switching clutch 43 on and off is directly connected to the leading end, and the shift lever shown in FIGS. 4 (A) and 5 is used.
When the left and right sides 65 are oscillated, the switching clutch 43 is in the “on” state on the reverse rotation shaft 41 side, and when the right side is oscillated, the switching clutch 43 is in the “off” state and is “on” operation on the case 3 side. Locked.

The tip of the other swing arm 76 is connected to an operation system 78 such as a wire or a rod (both not shown) for performing a shift operation by moving the sub-transmission gear 13 right and left, and FIG. 3 and FIG. As shown in the figure, the lever gear 66 swings back and forth along the shift range 66a of the lever guide 66 in the range from the middle speed range M to the low speed line L, and the sub-transmission gear 13 is switched to each position.

Due to the above mechanism, the switching clutch 43 is turned on only when the sub-transmission gear 13 is at a middle / low speed position other than the high speed position. These operating systems can be used for both mechanical operation of rods and wires and hydraulic operation via valve operation.

Next, the linking operation of the side clutch gears 23, 24 and the friction clutches 46, 47 will be described. This operation corresponds to the left and right swing of the steering lever 79 shown in FIGS. 1, 3, and 6. Done. Incidentally, in this embodiment, the steering lever 79 is a dual-purpose lever capable of vertically moving the pre-processing unit of the combine by swinging back and forth, and a description of the structure of the swinging back and forth will be omitted.

The steering lever 79 has its lower end pivotally supported by a shaft 81 so as to be able to swing left and right.A lower end of the swing is provided with a drive lever 82 projecting downward, and further below the lower end, arms 84a and 84b are provided at the lower end left and right. A protruding inverted T-shaped plate 84 is rotatably supported by a shaft 83. At the upper end of the plate 84, pins 86a, 86b are provided so as to be in contact with the left and right sides of the drive lever 82, and at the ends of the arms 84a, 84b, either the left or right of the friction clutch 46, 47 is connected. The base end portions 87a and 87b of an operation system 87 including a wire or a rod which is operated alternatively are connected.

When the steering lever 79 is swung to the left or right from the upright neutral position by the above configuration, one of the left or right side clutch gears 23, 24 is moved through the operation system 87 to the center gear 20.
When it is released from the state and becomes "disconnected" and further swings, the friction clutch 46 or 47 is selectively operated in response to the swing, and at the time of maximum braking, the reverse rotation shaft 41 and the friction clutch
46 or 47 is locked.

The hydraulic operation will be described in more detail.
8 controls the switching of the switching valve 96 shown in FIG. 8 and controls the pressure proportional control valve 89 shown in FIG. That is, the operation system 87 is connected to one side of an L-shaped arm 92 whose bending portion is pivotally supported on the shaft 91, and the other side of the arm 92 is connected to the pressure proportional control valve 89 according to the swing amount of the steering lever 79. The rod 89a is pressed and slid, and the large and small springs 89c, 89d, 8 in the cylinder 89b are changed according to the sliding amount of the rod 89a.
Out of 9e, the springs 89e, 89d, 89c having small elastic coefficients and the valve body 89f are sequentially pressed. As a result, a hydraulic pressure is formed on the primary side in accordance with the elastic coefficients of the springs 89c to 89e and the pressing load at each stage, and the cylinder 59 of the friction clutches 46, 47 is selectively operated.

FIG. 8 is a circuit diagram of the hydraulic operation system. In the steering control circuit 95 connected via the pump 94, one of the left and right friction clutch cylinders 59 and 59 and the left and right "off" operation of the side clutch cylinder 93 are provided. A switching valve 96 is provided for selectively selecting either one of the left and right operation circuits 97a, 97
b is connected to the side clutch cylinder 93, respectively.
On the way, it branches to a pressure proportional control valve 89, and a throttle valve 98 and a check valve 99 are provided in each of the branch circuits.

With the above circuit configuration, for example, when the steering lever 79 is operated in the left swing direction, in the process of reaching each of the positions A to D,
At the A position, the side clutch gear 23 is in the "disengaged" state, and the springs 89e, 89d, 89c of the proportional control valve 89 sequentially act to increase the hydraulic pressure, the left friction clutch 46 sequentially increases the braking force, and makes a gentle left-turn. When turning the steering lever 79 to the right side when the turning state changes, such as when turning left or right on a sharp curve, turning left when the left crawler is stopped, or turning The clutch gear 24 and the right friction clutch 47 operate similarly. 90 is the steering lever 79
By side clutch cylinder 93 and friction clutch 46,4
7 represents a hydraulic control unit.

FIG. 9 shows the change in the operating position of the steering lever 79 and the operating load generated by each of the springs 89e, 89d, 89c. The change in the operating load almost corresponds to the change in the braking force of the friction clutches 46, 47. ing.

<Effects of the Invention> According to the present invention configured as described above, since the braking and reverse switching of each of the left and right traveling units is performed by one steering lever, the configuration of the operation unit is simple and the operability is improved. When turning the aircraft, the pattern of turning by gentle one-sided braking, turning by one-sided braking (spinning turn), and super-spinning turning by one-side reverse rotation from the running state is sequentially or in accordance with the swing operation amount of the steering lever. There is an advantage that the operation is selectively performed by one steering lever smoothly, and the operations corresponding to these operation patterns are performed by using both the left and right friction clutches.

Even if the above-described operation is enabled, the steering lever operation system does not need to be changed from the conventional steering lever operation system for brake operation, and there is no need to complicate the operation. In addition, there is an effect that the operation feeling seen from the change of the operation load is smooth and no erroneous operation occurs. Particularly when the switching clutch is operated to either the lock position or the reverse rotation input position, a braking force or a turning amount corresponding to the swing operation amount of the steering lever can be obtained, and the operation feeling is common. is there.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, FIG. 1 is an explanatory view showing a transmission and a part of an operation system thereof, FIG. 2 is a sectional view showing details of the transmission, and FIG. 4 (A) and 4 (B) are a rear view and a side view showing a structure of a shift lever, FIG. 5 is a plan view showing a shift lever pattern and a lever guide,
FIG. 6 is a rear view showing the structure and operation pattern of the steering lever, FIG. 7 is a sectional view of the pressure proportional control valve, FIG. 8 is a hydraulic circuit diagram of a friction clutch and a side clutch using the pressure control valve, FIG. 9 is a diagram showing a change in the pattern and the operation load during the steering operation. 3: Transmission, 41: Reverse shaft 43: Switching clutch, 46, 47: Friction clutch 65: Steering lever, 89: Pressure proportional control valve

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-45276 (JP, A) JP-A-3-139473 (JP, A)

Claims (1)

(57) [Claims] A reverse shaft (41) for reversing left and right running parts in a transmission (3) is supported, and said reverse shaft (41) is provided.
A switching clutch (43) that locks the transmission to the transmission (3) side or turns on the reverse transmission input, and a side clutch that turns on and off forward power on the left and right traveling parts, The left and right friction clutches (46), (47) are hydraulically controlled to brake the left and right running parts or to transmit the reverse rotation of the reverse rotating shaft (41) to the left and right running parts on the reverse rotation shaft (41).
One steering lever (79) for controlling the friction clutches (46), (47) and the side clutch in conjunction with the left or right swing is provided on the driver's seat side. In the mechanism, the operating system of the steering lever (79) increases the hydraulic pressure in accordance with the amount of left or right operation of the steering lever (79), thereby locking the switching clutch (43). Left or right friction clutch (46), (47) in position
At the reverse rotation input operation position of the switching clutch (43), the left or right friction clutch (46),
(47) In addition to the increase in the braking force, the reverse input clutch “ON”
A steering device for a traveling work vehicle provided with a pressure proportional control valve (89) acting in the direction.