JP3411432B2 - Work vehicle operation control structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering operation structure for a work vehicle in which a pair of left and right traveling devices and a pair of hydrostatic continuously variable transmissions are interlocked with each other so that each traveling device can be independently driven. .

[0002]

2. Description of the Related Art Conventionally, as a steering operation structure for a work vehicle of this type, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-10030, a pair of hydrostatic continuously variable transmissions have bevel gear mechanisms. One that can be linked to a single steering operation tool and a single gearshift operation tool through a mechanical linking mechanism such as a link mechanism or the like to enable forward and backward shifting operations and steering operations. Was known.

[0003]

However, in the above-mentioned conventional structure, a mechanism for interlockingly connecting a single steering operation tool, a single speed change operation tool, and a hydrostatic continuously variable transmission. In addition, since a mechanical linking mechanism having a relatively complicated structure such as a bevel gear mechanism and a link mechanism is used, it takes a lot of time for assembling work and maintenance work, and the parts cost is high. There was a problem such as

The present invention has been made in view of the above circumstances, and an object thereof is to provide a steering operation structure for a work vehicle which has a simple structure and can be constructed at low cost.

[0005]

[Means for Solving the Problems]

(Structure) The work vehicle steering operation structure according to claim 1 of the present invention is configured such that a pair of left and right traveling devices and a pair of hydrostatic continuously variable transmissions are interlocked with each other so that each traveling device can be independently driven. In the steering operation structure of the work vehicle, one end of an inner wire of a push-pull wire for applying a turning force to the shift operation shaft is connected to the shift operation shaft of each of the hydrostatic stepless transmissions, and the other end of the inner wire of the two push-pull wire, a single pre-reverse shift lever, connected as conjunction with pushed or pulled to the shifting operation of the front reverse shift lever, and the respective push-pull
The outer wire of the wire is closer to the hydrostatic stepless transmission.
One end of the push-pull wire and the other end of the outer wire of each push-pull wire and the forward / reverse shift lever.
And a steering operation tool that is operated separately from the other, so that the other end of the outer wire is moved along the push-pull direction of the push-pull wire in accordance with the steering operation amount of the steering operation tool. The feature is that it is linked to.

(Operation) According to the structure of claim 1 of the present invention, the inner wire of the push-pull wire for applying the turning force of the gear shifting operation to the gear shifting operation shaft of each hydrostatic stepless transmission is provided. While connecting one end, the other end of the inner wire of the both push-pull wires is connected to a single forward / reverse speed change lever so as to be pushed / pulled in conjunction with the speed change operation of the forward / reverse speed change lever. Moreover, the other end of the outer wire of each push-pull wire and the steering operation tool are arranged along the pushing / pulling direction of the push-pull wire corresponding to the steering operation amount of the steering operation tool. Since they are linked so as to move, the forward / backward speed change lever and the steering operation tool and the speed change operation shaft of the hydrostatic continuously variable transmission have a structure in which they are connected by a push-pull wire,
The structure is such that a part of the steering operation tool and the push-pull wire are mechanically linked to each other. When the forward / reverse speed change lever is operated to the forward speed increasing side or the reverse speed increasing side,
Both push-pull wires actuate the speed change operation shaft of each hydrostatic stepless transmission to the forward speed increasing side or the reverse speed increasing side, whereby the vehicle moves straight forward or backward. When the steering operation tool is steered in the straight forward or reverse straight state, the push-pull wire on the steering side is moved by the steering operation lever via the mechanical simple linkage mechanism. When the displacement of the hydrostatic continuously variable transmission is decelerated, and when the operation amount of the steering operation tool further increases, the hydrostatic continuously variable transmission can be operated so as to reversely drive beyond neutral. As a result, the aircraft will be steered.

(Effect) Therefore, according to the configuration according to claim 1 of the present invention, a single forward / reverse speed change lever and a steering operation tool are simply formed by using the push-pull wire and a simple mechanical linkage mechanism. Since a pair of hydrostatic continuously variable transmissions are operably linked, a gear shift operation and a steering operation can be performed satisfactorily with a single gearshift lever and a single steering operation tool. The structure is extremely simple, and the assembling and maintenance of the structure can be simplified, and the cost of parts can be greatly reduced and the working efficiency can be improved.

(Structure) A work vehicle steering operation structure according to claim 2 of the present invention is characterized in that in the structure of claim 1, the steering operation tool is constituted by a rotation operation handle. The configuration.

(Operation) According to the second aspect of the present invention, the steering operation tool is composed of the rotary operation handle, so that the hydrostatic stepless shift of the steering operation amount of the rotation operation handle is performed. The structure for linking the push-pull wire as a transmission mechanism to the gear shift operation shaft of the device can also be configured to be displaced in conjunction with the rotary operation handle, for example, so that an extremely simple interlocking connection structure can be obtained and the steering operation can be performed. A person can perform a desired steering operation by rotating the rotary operation handle with a rotation amount according to the degree of the steering operation.

(Effect) With the configuration according to the second aspect of the present invention, it is possible for the operator to easily operate the vehicle and to make it structurally simple.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combine as an example of the work vehicle. This combine is equipped with a threshing device 3, a control section 4, a grain collecting section 5, etc. on a machine body 2 supported by a pair of left and right crawler traveling devices 1 and 1 as a traveling device, and is equipped with the machine body 2 The cutting pretreatment unit 6 is mounted on the front side of the so that it can swing up and down around the horizontal axis X. Then, as shown in FIG.
A speed change lever 7 as a forward / reverse speed change lever is provided so as to be swingable back and forth, and a steering handle 8 as a steering operation tool is provided. The pair of left and right crawler traveling devices 1 and 1 are independently driven by the hydrostatic continuously variable transmissions H and H, respectively.

A steering operation structure for interlockingly connecting the speed change lever 7 and the steering wheel 8 to the hydrostatic continuously variable transmissions H and H will be described below. As shown in FIG. 2 and FIG. 3, the hydraulic pumps P, P of the pair of hydrostatic continuously variable transmissions H, H have a speed change operation shaft 9 for changing the swash plate angle for changing and adjusting the discharge oil amount. , 9 are provided. Operation arms 10, 10 are integrally provided on the shift operation shafts 9, 9, and one end rods of inner wires 11a, 11a of the push-pull wires 11, 11 are connected to the operation arms 10, 10, respectively. The push-pull wires 11, 11
The outer wires 11b, 11b on one end side of are fixed to the machine body 2. The other ends of the inner wires 11a, 11a of the push-pull wires 11, 11 are both connected to the speed change lever 7.

As shown in FIGS. 2 and 3, the steering handlebar 8 is a rotary operation handlebar. A shift gear 13 is spline-fitted to the handle shaft 12 so as to be slidable in the axial direction of the handle shaft 12 and integrally rotatable in the rotating direction. A lever shaft 14 is provided rotatably around the shaft axis in parallel with the shaft axis of the handle shaft 12, and the lever shaft 14 is provided with a pair of driven gears 15 and 16 in the axial direction. Further, a counter shaft 17 is rotatably provided in parallel with the axis of the handle shaft 12, and a counter gear 18 is attached to the counter shaft 17.
Is always meshed with one of the driven gears 15 and 16 (driven gear 16). The shift gear 13 is
As shown in FIG. 3, the shift operation is performed by an electric actuator 19 using a solenoid, and a state in which only the driven gear 15 is engaged and a state in which only the counter gear 18 is engaged. It is configured so that it can be switched by shifting to and. A pair of left and right lever arms 20L and 20R are integrally connected to the lever shaft 14, and the pair of push-pull wires 1 are attached to respective tip portions of the pair of left and right lever arms 20L and 20R.
The other end portions of the outer wires 11b and 11b of Nos. 1 and 11 are fixedly installed. Further, a limit switch 21 for detecting that the shift lever 7 is operated to the reverse side is provided, and when the limit switch 21 is turned on by the reverse side operation of the shift lever 7, the electric actuator 19 is operated. When the limit switch 21 is electromagnetically driven to shift the shift gear 13 so as to mesh with the counter gear 18, and the limit switch 21 is turned off by forward operation or neutral operation of the speed change lever 7, the electric actuator 19 is returned by a spring (not shown). The shift gear 13 is configured to be biased to shift so as to mesh with the driven gear 15.

With the above structure, the steering wheel 8
When the speed change lever 7 is operated to the forward speed increasing side in a state where the neutral position is neutral, both push-pull wires 11,
The inner wires 11a and 11a of 11 are both pulled by the same amount, and the speed change operation shafts 9 of the hydrostatic continuously variable transmissions H and H are
9 is operated to the forward speed increasing side by the same amount, and the crawler traveling devices 1 and 1 are driven to the forward side at a constant speed to move straight ahead. When the steering handle 8 is rotated to the left, for example, in the straight forward movement state, the left lever arm 20L causes the outer wire 11b of the push-pull wire 11 corresponding to the left crawler traveling device 1 to move to the shift lever 7.
Since the pulling operation is performed closer to the pulling operation, the shift operating shaft 9 of the hydrostatic continuously variable transmission H on the left side corresponding to the pulling operation of the outer wire 11b is moved to the neutral side or the reverse speed increasing side by the inner wire 11
The rod on the one end side of a is pushed and the right lever arm 20R moves the outer wire 1 of the push-pull wire 11 corresponding to the right crawler traveling device 1.
Since 1b is pushed to the side away from the shift lever 7, the shift operation shaft 9 of the hydrostatic continuously variable transmission H on the right side of the pushing amount of the outer wire 11b is moved toward the forward speed increasing side on one end side of the inner wire 11a. Will pull the rod. As a result, the left crawler traveling device 1 is operated to decelerate or move to the reverse side, and the right crawler traveling device 1 is operated to move to the forward speed-increasing side. When the steering handle 8 is operated to the right, the same operation is performed as described above, and the hydrostatic continuously variable transmission H on the right is operated.
Is operated to the deceleration or reverse side, and the crawler traveling device 1 on the left side is operated to the forward speed-increasing side, so that the aircraft turns right. When steering to the left, for example, when the shift operation shaft 9 of the hydrostatic continuously variable transmission H on the right reaches the maximum speed increasing state, the shift operation shaft 9 cannot be operated any further, so the steering handle When the operation of 8 to the left steering side is still performed, the speed change lever 7 frictionally held at the operation position is pulled to the deceleration side by the push-pull wire 11 on the right side. On the contrary, when the speed change lever 7 is operated to the reverse speed increasing side, the inner wires 11a, 11a of both push-pull wires 11, 11 are pushed by the same amount in association with the operation, and the hydrostatic stepless transmission H, The gear shift operation shafts 9 and 9 of H are operated to the reverse speed increasing side by the same amount, and the crawler traveling devices 1 and 1 are driven to the reverse speed at a constant speed and go straight ahead. When the steering handle 8 is steered to the left in order to steer the aircraft to the left when the vehicle is moving backward, the limit switch 21 that detects an operation to the reverse side of the speed change lever 7 is turned on to turn the electric actuator 19 on.
Is operated to engage the shift gear 13 with the counter gear 18, the left lever arm 20
L pushes the left outer wire 11b away from the gear shift lever 7, thereby operating the left gear shift operating shaft 9 toward the neutral side for deceleration or forward acceleration, and the right lever arm 20R. In this case, the right outer wire 11b is pulled so as to approach the speed change lever 7, and the right speed change operation shaft 9 is operated to the reverse speed increasing side, so that the vehicle turns left.

As the steering operation tool, a swinging operation type lever may be used instead of the rotation operation handle.

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 configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an overall side view showing a combine.

FIG. 2 is a schematic explanatory view showing a steering operation structure for a traveling device.

FIG. 3 is a schematic explanatory view showing a forward / reverse switching structure in a steering handle operation system.

[Explanation of symbols]

1 traveling device 7 Forward / reverse shift lever 8 Steering controls 9 Gear shifting operation tool 11 push pull wire 11a Inner wire 11b outer wire H hydrostatic continuously variable transmission

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60K 20/00-20/08 F16H 59/00-59/12 F16H 61/26-61/64 F16H 63 / 00-63/38 B62D 11/00-11/24 G05G 1/00-25/04

Claims (2)

(57) [Claims] 1. A control of a work vehicle in which a pair of left and right traveling devices (1) and a pair of hydrostatic continuously variable transmissions (H) are interlockingly connected to each other so that each traveling device (1) can be independently driven. An operation structure, wherein a shift operation shaft (9) of each of the hydrostatic continuously variable transmissions (H)
Is connected to one end of an inner wire (11a) of a push-pull wire (11) for applying a turning force to the shift operation shaft (9), and both push-pull wires (11) are connected.
The other end of the inner wire (11a) is connected to a single forward / reverse speed change lever (7) so as to be pushed and pulled in conjunction with the speed change operation of the forward / reverse speed change lever (7), and Outer wire of each push-pull wire (11)
(11b) One side closer to the hydrostatic continuously variable transmission (H)
While fixing the end side to the machine body (2), the other end of the outer wire (11b) of each push-pull wire (11),
A steering operation tool (8) which is operated separately from the forward / reverse speed change lever (7), and the outer wire (11b) corresponding to the steering operation amount of the steering operation tool (8). Of the push-pull wire (11) is connected to move the other end of the push-pull wire (11) along the pushing and pulling direction. 2. The steering operation structure for a work vehicle according to claim 1, wherein the steering operation tool (8) is constituted by a rotation operation handle.