JPH06127282A - Speed change operation structure for working vehicle - Google Patents

Abstract

PURPOSE:To provide a speed change operation structure which enables smooth speed change operation with less backlash and having simple structure. CONSTITUTION:A first rod 9 of a grip operation part 19 is interlockingly connected for free bending in the optional direction to a second rod 12 on the side of a speed change device 8, intermediate parts of respective rods 9, 12 are swingably supported on a machine body fixing part 11 via ball joints 10, 13 and engaged and guided along a fixed guiding part 25 so as to allow swinging of the first rod 9 in the predetermined direction. A guide member 23 for allowing swinging in the direction crossing the predetermined direction is provided, speed change operation tools 21, 22 of the speed change device 8 are selected by means of swinging operation in the predetermined direction of the grip operation part 19 and speed change shift operation is conducted by the swinging operation in the crossing direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work vehicle gear shift operation structure.

[0002]

2. Description of the Related Art Conventionally, in a shift operation structure for a work vehicle, an operation shaft is arranged along a vertical direction on the side of a steering wheel as shown in, for example, Japanese Patent Laid-Open No. 2-237823. A tubular portion is fitted onto the operating shaft so as to be rotatable relative to the operating shaft, and a gear shift lever is supported rotatably around an axis intersecting with the operating shaft. In addition to providing an engaging member that engages with, the pair of vertically oriented shift fork shafts are interlockingly linked to the lower ends of the operating shaft and the cylinder shaft, and the shift lever is switched up and down to select the operation target. There has been a structure in which a gear shift operation is performed by turning around an axis.

[0003]

The above conventional structure has the advantage that the gear shift lever and the gear shift fork shaft can be linked with each other by a relatively simple structure, but it is necessary to provide a plurality of gear shift fork shafts in a vertical posture. However, since the transmission gears are generally provided on the same axis, there is a drawback that the linkage structure between the transmission fork shaft and the shift fork in the transmission case becomes complicated. Further, since the operation shaft is arranged in a substantially vertical posture, if the speed change lever is arranged close to the lower side of the steering handle to improve the operability,
Since the lower part of the operation shaft is located at the foot of the driver in the driving step, the foot of the operator is narrowed and there is a possibility of getting caught when getting on and off, and there is still room for improvement. The present invention aims to eliminate the above-mentioned problems.

[0004]

A characteristic configuration of the present invention is that a first rod on the side of a grip operating portion and a second rod on the side of a transmission are interlockingly connected in a freely bendable manner, and the middle portion of each rod is connected. Are respectively supported by a body fixing portion via spherical bearings so as to be freely swingable, and are engaged and guided along a fixed guide portion to allow the first rod to swing in a predetermined direction, and also to perform the predetermined direction. A guide member that allows swinging in a direction intersecting with is provided, a shift operation tool of the transmission is selected by swinging operation of the grip operation portion in the predetermined direction, and a shift operation is performed by swinging operation in the intersecting direction. It is configured to perform a shift operation.

[0005]

When the grip operating portion is manually operated so that the first rod is engaged and guided by the guide member and swings in a predetermined direction in which the movement is allowed, the first rod uses the support portion of the spherical bearing in the middle as a fulcrum. The shift operation tool to be operated is selected by swinging the balance and interlockingly swinging the second rod flexibly connected to the other end side with the ball joint support portion in the middle as a fulcrum.
Next, when the grip operating portion is operated in a direction intersecting with the predetermined direction, the guide member allows the first rod to swing in that direction, and the second rod interlocks and swings to be selected. Is operated to shift gears.

[0006]

Therefore, even if the distance between the grip operating portion and the transmission is relatively large, the speed change can be achieved by simply swinging the plurality of freely bendable rods around an intermediate fulcrum. It can be operated, smooth shift operation with less rattling is possible, only one shift operation shaft is required,
It is possible to simplify the linkage structure with a plurality of gear shift operation tools.
Further, for example, even if the configuration in which the grip operation section is arranged near the steering handle is adopted, there is no restriction in the arrangement direction of the rod, so that there is a problem that the space at the foot of the operator is narrowed. Does not happen.

[0007]

Embodiments will be described below with reference to the drawings. Figure 4
Fig. 1 shows an agricultural tractor which is an example of a work vehicle. This agricultural tractor is provided with a driving unit 3 above the intermediate portion between the front and rear wheels 1, 2, an engine 5 is mounted in a hood 4 at the front of the machine body, and a mission case 6 is connected to the rear portion of the engine 5. I am doing it. Next, the shift operation structure will be described. A gear-type main transmission 8 is installed inside the mission case 6 at a position below the steering handle 7, and the gear shift lever A of the main transmission 8 is a steering handle 7.
It is arranged near the lower side of the so-called column shift type. As shown in FIGS. 1 and 2, the middle portion of the first rod 9 constituting the speed change lever A is supported by the body fixing portion 11 via the ball joint 10 so as to be freely rotatable, and the first rod 9 A second rod 12 is interlockingly connected to a lower end portion of the second rod 12 so as to be bendable in an arbitrary direction. Similarly, the second rod 12 also has an intermediate portion supported by a body fixing portion 11 via a ball joint 13 so as to be freely rotatable. is there. That is, the tubular member 14 is welded and fixed to the lower end portion of the first rod 9, the end portion of the second rod 12 is formed into a spherical shape, and the spherical portion 12a is inserted into the tubular member 14 to be linked and freely bent. It is interlockingly linked freely and slidably in the axial direction. Also, the lower end portion of the second rod 12 is welded and fixed to the tubular member 15 similarly to the first rod 9, and is inserted into the spherical shaft portion 18 formed on the operation member 17 integrally connected to the speed change operation shaft 16 so as to be linked. Then
It is linked so that it can be freely bent and slid in the axial direction. The upper portion of the first rod 9 is bent and formed in a dogleg shape so that the grip operating portion 19 is located laterally outward of the steering handle 7, and the lower half portion of the first rod 9 and the second rod 12 are substantially vertical. The grip operation part 19 is arranged as much as possible along with the rear tilted position, which is located slightly rearward as it goes upward.
A wide space can be provided in the driver's step 20 at the feet of the operator while the operator can easily perform the operation near the operator. The gear shift operation shaft 16 is provided in a horizontal posture so as to project laterally from the mission case 6 to one side.
By selecting one of the two shift shift forks 21 and 22 [an example of a shift operation tool] to be operated by sliding in the axial direction, the shift is selected by rotating around the axial center. A fork is used to shift gears (not shown) to shift gears. Incidentally, as shown in FIG. 3, the forward first speed F1 and the reverse state R are switched by the shift operation of one shift fork, and the second forward speed F2 and the forward third speed F1 are switched by the shift operation of the other shift fork.
The speed F3 can be switched.

A guide member 23 is mounted near the intermediate fulcrum of the first rod 9 to allow the rod 9 to swing in a predetermined direction and to swing in a direction intersecting with the predetermined direction. is there. The guide member 23 is formed by bending a plate material in a stepwise manner, integrally fixing the first rod 9 to the upper step surface 23a in a penetrating state, and forming a notch recess 24 in the lower step surface 23b on the other end side. . The lower step surface 23b in which the notch recess 24 is formed is arranged so as to be positioned at substantially the same level as the fulcrum of the ball joint 10, and the notch recess 24 is formed in the machine body fixing portion 11 along the longitudinal direction of the guide shaft portion 25 [. An example of a fixed guide portion] is configured to be allowed to swing in the vertical direction. Further, the width of the cutout recess 24 is equal to that of the guide shaft portion 2.
5 is set to be slightly larger than the outer diameter to form a gap, and the guide member 23 is twisted by an amount corresponding to the gap to allow swinging in the front-rear direction about the ball joint 10 as a fulcrum (see FIG. 3). . Therefore, when the laterally-oriented gripping operation portion 19 of the first rod 9 is operated in the up-down direction, the notch recess 24 of the guide member 23 is engaged and guided along the guide shaft portion 25 to swing, and the second rod 12 Interlockingly swings to shift the shift operation shaft 16 in the axial direction to select the shift fork, and swinging the grip operating portion 19 back and forth with any one selected, the notch recess 24 of the guide member 23 The twisting operation allows the swing, and the gear shift operation shaft 16 rotates and the gear slides to shift gears.

Another rod having an intermediate portion supported by a ball joint may be interposed between the second rod 12 and the operating member 17 in a linked state.

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

[Brief description of drawings]

FIG. 1 is a partially cutaway rear view showing a gear shift operation system.

FIG. 2 is a partially cutaway side view showing a shift operation system.

FIG. 3 is a cutaway plan view of a guide member mounting portion.

FIG. 4 is an overall side view of an agricultural tractor.

[Explanation of symbols]

 8 Gearbox 9 1st rod 10,13 Ball joint 12 2nd rod 19 Grip operation part 21,22 Gearshift operation tool 23 Guide member 25 Fixed guide part

Claims (1)

[Claims] 1. A first rod (9) on the side of a grip operating portion (19) and a second rod (12) on the side of a transmission (8) are interlockingly connected in a freely bendable manner, and each rod (9). ),
The intermediate part of (12) is supported by the body fixing part (11) so as to be freely swingable via spherical bearings (10) and (13), and is engaged and guided along the fixed guide part (25). A guide member (23) that allows the first rod (9) to swing in a predetermined direction and also to swing in a direction intersecting the predetermined direction is provided, and the predetermined portion of the grip operation part (19) is provided. By the swinging operation in the direction, the gear shift operation tool (21) of the transmission (8),
(22) is selected, and a shift operation structure of a work vehicle configured to perform a shift operation for shifting by swinging operation in the intersecting direction.