JPS6234829Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transmission device for a mobile agricultural machine such as an agricultural tractor.

Conventionally, the transmission of agricultural tractors has generally been installed at a low position on the machine body, and the positioning mechanism that determines the operating position of the rotation axis of the inner arm that slides the transmission sliding gear inside the transmission case is located in the transmission case. Since the positioning mechanism is installed outside, when plowing or plowing rice fields with an agricultural tractor, the above positioning mechanism is easily exposed to muddy water or mud and becomes inoperable or malfunctions, and operations such as shifting gears are often impossible. There was an inconvenience.

In view of the above-mentioned conventional circumstances, the present invention has been developed by attaching a cover body to the outer arm to cover the positioning mechanism that determines the operation position of the rotation axis of the inner arm, which is configured outside the mission case. , to reliably protect the positioning mechanism that determines the operating position of the rotating shaft of the inner arm from muddy water and muddy soil, thereby preventing the positioning mechanism from becoming inoperable or malfunctioning due to muddy water, muddy soil, etc. It is an object of the present invention to provide a transmission device for a mobile agricultural machine, etc., which can prevent such problems and always perform operations such as shifting smoothly and accurately.

The structure of the present invention will be described with reference to an embodiment shown in the drawings. The drawings show an example of a transmission device for an agricultural tractor, 1 is a transmission case, 2 is a transmission sliding gear, An inner arm 3 is engaged with the speed change sliding gear 2, and a rotating shaft 4 of the inner arm 3 projects outward from a shaft hole 5 of the transmission case 1. Reference numeral 6 denotes an outer arm, and the outer arm 6 is attached to the protruding end of the rotating shaft 4 with a retaining pin 7. Reference numeral 8 denotes an operating lever for changing gears. The operating lever 8 is rotatably supported on a shaft 9, and a rod is connected between the protruding arm 10 of the operating lever 8 and the protruding pin 11 of the outer arm 6. connected by 12.

On the other hand, outside the mission case 1, a positioning mechanism 13 is constructed between the rotation shaft 4 of the inner arm 3 and the outer arm 6 to determine the operating position of the rotation shaft 4 of the inner arm 3. That is, a disk-shaped fixing plate 15 having a fitting hole 14 fitted to the rotating shaft 4 is fixed to the outside of the mission case 1 by inserting and screwing a bolt 17 into the fixing hole 16. , the fixing plate 15 has ball recessed holes 18a, 18 for positioning.
b, 18c are formed, and a ball fitting tube 19 is provided protruding from the outer arm 6 in correspondence with the ball recessed holes 18a, 18b, 18c. compression spring 21
The balls 20 are supported and fitted in the outer arm 6 so that they can freely move in and out of the ball recessed holes 18a, 18b, and 18c on the disk 15 side according to the rotation of the outer arm 6. The position where the ball 20 has entered the ball recess hole 18a is "high speed", the position where the ball 20 has recessed into the ball recess hole 18b is "medium speed", and the ball recess hole 18c is "medium speed".
Positioning is performed at "low speed" at the position where the outer arm 6 is invaginated, and the outer arm 6 has a positioning mechanism 1.
No. 3 cover bodies 22 are attached. This cover body 22 has a shape that covers the outer periphery of the fixed plate 15, and covers the positioning mechanism 13 in an enveloping manner. Note that the fixed plate 15
A part of the fitting hole 14 for the rotating shaft 4 is formed to be enlarged, and when fitting into the groove 23 of the rotating shaft 4, the fitting hole 14 is inserted into the rotating shaft 4 from the wide part of the fitting hole 14, and the narrow part of the fitting hole 14 is enlarged. By moving the portion in the direction of engagement with the groove portion 23, it can be easily attached. (See Fig. 3) In Fig. 4, reference numeral 24 is an operating lever for forward and reverse rotation in the transmission, and this operating lever 24 is also rotatably supported on the shaft 9.
It is also connected via a rod 25 to an outer arm 26 for forward and reverse rotation. The mechanism for forward and reverse rotation also includes a positioning mechanism 13' made up of a fixed plate 15, a ball 20, a compression spring 21, etc. in the same way as the mechanism for speed change, and this positioning mechanism 13' is also attached to the outer arm 26. It is constructed so as to be covered by an attached cover body 22' similar to the above-mentioned one.

In the configuration as described above, when the operating lever 8 for shifting is tilted back and forth, the shifting sliding gear 2 is slid through the rod 12, the outer arm 6, the rotating shaft 4, and the inner arm 3. and the gears are changed. In each speed change state, the ball 20 is inserted into the ball recessed hole 18 in the positioning mechanism 13.
By invaginating any one of a, 18b, and 18c, the speed is determined to be "high,""medium," or "low," respectively.

On the other hand, when the operation lever 24 for forward and reverse rotation is tilted, the sliding gear for forward and reverse rotation is slid via the rod 25, outer arm 26, etc., and the state can be switched to normal rotation or reverse rotation. The positioning is performed by the positioning mechanism 13' in the same manner as described above. By the way, in the positioning mechanism 13, the cover body 22 completely covers the inside of the fixed plate 15 so as to cover the outer periphery of the fixed plate 15, so that the transmission case 1 may be exposed to muddy water, mud, etc. However, the positioning mechanism 13 is always kept in a state of smooth and accurate operation, and will not become inoperable or malfunction due to muddy water, muddy soil, etc.

The same applies to the positioning mechanism 13' for forward and reverse rotation. Therefore, even when the transmission is exposed to muddy water or soil, such as plowing or plowing rice fields with an agricultural tractor that is installed at a low position on the body, the gear shift operation or forward/reverse operation can always be carried out smoothly and accurately. It can be done.

In short, the present invention has the rotating shaft of the inner arm that slides the sliding gear inside the mission case protrude outside the mission case, and the outer arm is attached to the end of the rotating shaft of the inner arm. In a transmission device in which this is connected to an operating lever, a disk-shaped fixing plate fitted to the rotating shaft is attached to the outside of the transmission case, and the fixing plate is placed in an enveloping shape opposite to the fixing plate. A cover body is attached to the outer arm, and a positioning mechanism consisting of a ball, a compression spring, etc. is provided between the fixed plate and the cover body, which determines the operating position of the rotating shaft. By completely covering the positioning mechanism that determines the operating position of the rotation axis of the inner arm with the cover body on the outer arm side, the positioning mechanism can be reliably protected from muddy water and mud. This has extremely useful practical effects, such as preventing inoperability or malfunction due to dirt, mud, etc., and making it possible to always carry out operations such as gear changes smoothly and accurately.

[Brief explanation of the drawing]

The drawings show an embodiment of the transmission device for a mobile agricultural machine according to the present invention, in which FIG. 1 is a sectional view showing the main parts of the transmission device for an agricultural tractor, FIG. 2 is a front view of a part thereof, Figure 3 is a side view of the same as above, Figure 4
The figure is an exploded perspective view of the main parts. In the figure, 1 is a transmission case, 2 is a transmission sliding gear, 3 is an inner arm, 4 is its rotation shaft, 6 is an outer arm for shifting, 8 is an operation lever for shifting, 12 is a rod, 13, 13' are positioning mechanisms, 15, 15' are fixed plates, 18
a, 18b, 18c are ball recessed holes, 19 is a ball fitting tube, 20 is a ball, 21 is a compression spring, 2
2 and 22' are cover bodies, 24 is an operating lever for forward and reverse rotation, 25 is a rod, and 26 is an outer arm for forward and reverse rotation.

Claims (1)

[Scope of utility model registration request] The rotating shaft of the inner arm that slides the speed change sliding gear inside the mission case is made to protrude outside the mission case, and an outer arm is attached to the end of the rotating shaft of the inner arm, and this is used as an operating lever. In the connected transmission, a disk-shaped fixed plate fitted to the rotating shaft is installed on the outside of the transmission case, and a cover body is provided opposite to the fixed plate to cover the fixed plate in an enveloping manner. A transmission device for a mobile agricultural machine, characterized in that it is attached to the outer arm and is provided with a positioning mechanism consisting of a ball, a compression spring, etc., which determines the operation position of the rotating shaft, between the opposing fixing plate and the cover body. .