JPH018419Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of a change lever device for a tractor, which prevents a decrease in the strength of the fork due to its complicated shape, matches human factors, and improves comfort. Moreover, it is an object of the present invention to provide a change lever device that prevents accidental leakage of gear oil.

Conventionally, there are two types of change lever devices for changing the transmission gear mechanism of a tractor: a direct shift method and a side select method.

Fig. 1 shows an overview of the side select system, in which a gear change mechanism (not shown) is built into the body 4 of a tractor 3, which is shown as a two-axle, four-wheel type with front wheels 1 and rear wheels 2. , a change lever 6 provided on the side of the driver's seat 5 for shifting the gear.
The gear change is carried out by rotating the select rod 7 as a fulcrum and selecting operation by moving the select rod 7 in the axial direction.According to this, the change lever 6 is located behind the entrance 8. This makes it easier to get on and off the vehicle, and the movement of the lever can be matched to the human factor, but on the other hand, the shape of the shift fork, etc. must be improved because the lever is further away from the change lever mechanism. Not only that, but the fork is complicated in shape, which not only causes a decrease in strength, but also creates a complicated structure and troublesome assembly and disassembly.

On the other hand, in the direct shift method shown in FIG. 2, the change lever 9 is directly engaged with the shift gear, shifter, etc. of the transmission gear mechanism, so that the disadvantages of the side select method can be solved, but on the other hand, Since the lever 9 directly engages the shift gear, shifter, etc., the lever 9 inevitably protrudes from the vehicle body 4 in front of the driver's seat 5, which makes it difficult to operate and prevents the entrance/exit. There is a problem with making 8 narrower.

Furthermore, in both the side shift method and the direct shift method described above, gear oil 17 is contained within the vehicle body 4 as shown in FIG. 3, and in this case, air must be vented. A breather means such as a breather pipe is usually provided on the rear upper surface of the vehicle body 4, and as shown in FIG. , the oil level changed, and there was a risk of gear oil leaking unexpectedly while climbing a hill.

Therefore, the present invention utilizes the advantages of the conventional side select system and eliminates its disadvantages. Therefore, in the present invention, an opening is provided on the upper surface of the longitudinally intermediate portion of the vehicle body that contains gear oil. A plurality of shift rods are provided on a transmission stand that closes the opening so as to be slidable in the axial direction, and each of the shift rods is extended toward a driver's seat provided on the rear side of the vehicle body. A select rod is provided on the extension side in a direction perpendicular to the axial direction of the shift rod,
A change lever device for a tractor that operates a change lever provided on the select rod to change the speed of a speed change gear mechanism in the vehicle body via the shift rod, wherein a bottomed oil drain chamber is connected to the speed change table via a partition wall. an engaging portion of the extending portion of the shift rod and a select arm of the select rod that is engaged with and disengaged from the engaging portion are housed in the oil cutting chamber;
It is characterized in that it is provided with a through hole that communicates the opening and the oil cut chamber, and further includes a breather that opens the oil cut chamber to the atmosphere.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 3 to 8.

In FIG. 3, 10 is a tractor, 11 is a front wheel, 12 is a rear wheel, and 13 is a vehicle body.
A suitable speed change gear mechanism is built in, and the speed can be changed using a change lever 15 provided on the side of the driver's seat 14. In addition, in Figure 3, 1
Reference numeral 6 indicates a hydraulic system for lifting and lowering the working machine, and 17 indicates gear oil.

Referring to FIG. 4 and subsequent figures, reference numeral 18 denotes a gearbox, which is placed on the vehicle body 13 so as to cover an opening 19 formed approximately in the center of the vehicle body 13 in the longitudinal direction, and is secured by bolts or the like. installed.

Reference numerals 20, 21, and 22 indicate a plurality of shift rods, which are held parallel to each other and slidably in the axial direction on the wall 23 of the transmission platform 18. ，
Upper end boss portions of shift forks 27, 28, and 29 are attached via 26.

Reference numeral 30 denotes a transmission gear mechanism, which is built into the vehicle body 13 and which is connected to the shift forks 27, 28, 2.
9 to the object to be changed 31, such as a gear or shifter.
32 and 33 can be turned on and off freely, and in this embodiment, the shift forks 27 and 28 are connected to the bodies 31 and 32 to be changed.
The shift fork 29 is engaged with the object to be changed 33 via a relay shift rod 34 and a fork 35, respectively.

The shift rods 20, 21, and 22 each extend toward the driver's seat 14, and selector engaging portions 36, 37, and 38 are provided on the extending sides via bolts 39, 40, 41, etc. in this embodiment. installed. Note that each of the engaging parts 36, 37, and 38 has an upward opening shape, and the central engaging part 37 has no walls formed on the left and right sides, and the left and right engaging parts 36, 38 are adjacent to the engaging part 37. It has a so-called U-shape in plan with walls on the outside.

42 is the select rod, and the gear shift cover base 4
3, in a direction perpendicular to the axial direction of the shift rods 20, 21, and 22, that is, along the width direction of the vehicle body 13, so as to be rotatable about the axis and slidable in the axial direction.

A select arm 45 is attached to the select rod 42 via a pin 44, and the spherical end portion 46 of the arm 45 is capable of engaging and disengaging from the engaging portions 36, 37, and 38 as shown in FIGS. 4 and 5. There is.

A change lever 15 is attached to the protruding end of the select rod 42.

In addition, in the figure, the upper and lower surfaces of the transmission table 18 are parallel to each other, and the shift forks 27, 28,
A cover 47 is removably attached to the upper surface corresponding to 29.

Further, eight circumferential grooves 48 shown in FIG. 5 are formed in the select rod 42 in this example, and a ball 50 biased by a spring 49 can be freely engaged with and detached from the circumferential groove 48.
A positioning mechanism is configured here. In addition,
Shift rods 20, 21, and 22 are also provided with positioning mechanisms having a similar configuration.

Reference numeral 51 denotes a breather pipe, which is attached to the top of the transmission cover base 43 via a threaded pipe 52, and allows air to be vented through a through hole 53 and an oil drain chamber 54 shown in FIG. That is, a bottomed oil cut chamber 54 is connected to the transmission platform 18 via a partition wall, and the upper surface of the oil cut chamber 54 is closed by a transmission cover base 43 having a select rod 42. The engaging portions 36, 37, 38 and the select arm 46 provided on the extension side of the shift rods 20, 21, 22 are housed in, and a through hole 53 is provided to communicate the opening portion 19 and the oil drain chamber 54. , a breather 5 shown by a pipe that opens the oil cutting chamber 54 to the atmosphere.
1. Note that the through hole 53 may be formed by casting or machining. By providing the breather pipe 51 in the illustrated position, it is possible to prevent the gear oil 17 from leaking even when the vehicle is running uphill or descending as shown in FIGS. 1 and 2.

Next, the effect will be explained.

Change lever 1 located on the side of the driver's seat 14
5 to move the select rod 42 in the direction of arrow A in FIG. , 38.

Therefore, by rotating the change lever 15 about the select rod 42 in the direction of arrow B in FIG. The bodies to be changed 31, 32, and 33 are turned on and off through the gears 28 and 29, and in this embodiment, the body to be changed 31 is for the first and second speeds of the traveling system, and the body to be changed 32 is for the traveling system. They are used for the third and fourth speeds of the system, and the body 33 to be changed is used for creep on/off.

In addition, gear oil 1 is generated by the operation of the transmission gear mechanism 30.
7 rises, and for this reason, it is necessary to provide a breather function. is suppressed, the splashed oil is stored in the oil cutting chamber 54, and only the air flows through the breather 5.
1 and released to the atmosphere.

At this time, the splashed oil lubricates the select arm 46 and the engaging parts 36, 37, 38,
Moreover, the shift rods 20, 21, and 22 are lubricated.

Also, even when the tractor is climbing a slope, the gearbox 1
8 is located at an intermediate portion in the longitudinal direction of the vehicle body, and a breather 51 is provided near this area, so that unexpected leakage of gear oil is prevented.

The present invention is as described above, and has an opening on the upper surface of the middle part in the longitudinal direction of the vehicle body containing gear oil, and a plurality of shift rods can be slidably axially on a transmission platform that closes the opening. each of the shift rods is provided to extend toward a driver's seat provided on the rear side of the vehicle body, and a select rod extending in a direction perpendicular to the axial direction of the shift rod is provided on the extending side of the rod, and a change lever provided on the select rod. With the operation of
Since the transmission gear mechanism inside the vehicle body is operated through the shift rod, the basic function and effect are that it is compatible with human factors while preventing a decrease in the strength of forks, etc., and there is little risk of impairing the comfort of the vehicle. In addition, there are the following advantages.

A bottomed oil drain chamber is connected to the transmission via a bulkhead, and the opening is connected to the oil drain chamber through a through hole. It is also equipped with a breather that opens the oil drain chamber to the atmosphere, so that it can be kept inside the vehicle. The gear oil is stored in the oil drain chamber and can be prevented from leaking outside.

Further, even when the tractor climbs a slope, the breather is located at the middle portion of the vehicle body in the longitudinal direction, thereby preventing accidental leakage of gear oil.

Furthermore, since the engaging part and the select arm in the extending part of the shift rod are housed in the oil drain chamber,
The friction part between the engaging part and the select arm is lubricated, and the shift rod can also be lubricated, which has excellent wear resistance and improves durability.
The shift rod slides smoothly, allowing for reliable and light change operations.

[Brief explanation of the drawing]

FIG. 1 is an external view of a tractor equipped with conventional example 1;
Fig. 2 is an external view of a tractor equipped with Conventional Example 2, Fig. 3 is an explanatory view of the external appearance of the tractor according to the embodiment of the present invention during climbing and descending, and Fig. 4 is a cross-sectional side view of the main part of the embodiment of the present invention. Fig. 5 is a vertical cross-sectional rear view of Fig. 4, Fig. 6 is
The figure is an explanatory plan view, Fig. 7 is a partial plan view, and Fig. 8 is an explanatory plan view.
The figure is a partial rear view. 13... Vehicle body, 14... Driver's seat, 15... Change lever, 20, 21, 22... Shift rod, 27, 28, 29... Shift fork, 3
1, 32, 33... body to be changed, 36, 37,
38...Selector engaging portion, 42...Select rod, 45...Select arm.

Claims (1)

[Claims for Utility Model Registration] An opening 19 is provided on the upper surface of a longitudinally intermediate portion of a vehicle body 13 containing gear oil 17;
A plurality of shift rods 20, 21, 22 are provided on a transmission platform 18 that blocks the vehicle body 13 so as to be slidable in the axial direction. A select rod 42 extending in a direction perpendicular to the axial direction of the shift rods 20, 21, 22 is provided on the extending side of the rod, and by operating a change lever 15 provided on the select rod 42, the shift rods 20, 21,
In the change lever device for a tractor, which operates the speed change gear mechanism 30 in the vehicle body 13 via the gearbox 22, a bottomed oil drain chamber 54 is connected to the speed change table 18 via a partition wall, and the oil drain chamber 54 The engaging portion 3 at the extending portion of the shift rods 20, 21, 22 is located inside.
6, 37, 38 and the select arm 45 of the select rod 42 which is engaged and disengaged from the engaging portions 36, 37, 38, and a through hole 53 is provided to communicate the opening 19 and the oil cut chamber 54. A change lever device for a tractor, comprising a breather 51 for opening an oil cutting chamber 54 to the atmosphere.