JPH04274930A - Speed change operation structure of work vehicle - Google Patents

Abstract

PURPOSE:To enable the speed change lever to be returned lightly from advance side or retreat side to the neutral position of an advance-retreat changeover device, in case of operating a stepless speed change gear for run and the advance-retreat changeover device with one speed change lever. CONSTITUTION:This is constituted so that the advance-retreat changeover device may change it over to advance side F or retreat side R when the speed change lever 1 is operated to the end along the right-left operation course 19 corresponding to the neutral position N1 of a stepless speed change gear, and further this is provided with an operation course 20 on advance side, which extends from one end of the right-left operation course 19, and an operation course 21 on retreat side, which extends from the other end of this right-left operation course 19. One of the several ends of the advance side F and the retreat side R, which is positioned at the right or left in the right-left operation course 19, is provided with an auxiliary course 23, which allows the operation of the speed change lever 1 in the reverse direction to the operation course 20 or 23 on advance side or retreat side.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change operation structure for a working vehicle in which a continuously variable transmission for traveling and a gear shift type forward/reverse switching device are arranged in series.

0002

[Prior Art] Some working vehicles, such as agricultural tractors and walk-behind binders, are constructed so that the aforementioned continuously variable transmission and forward/reverse switching device can be operated simultaneously with a single gear shift lever. The transmission structure is as follows. In other words, the gear lever, the continuously variable transmission, and the forward/backward switching device are mechanically connected to each other by a linking rod, wire, etc., so that, for example, as shown in FIG.
The configuration is such that when the gear shift lever 1 is operated left and right along a left-right operation path 19 along the vertical direction in the drawing, the forward/reverse switching device is operated from the neutral position N2 to the forward side F and the reverse side R. Further, within this left and right operation path 19, the continuously variable transmission is operated to the neutral position N1. When the shift lever 1 is operated from the left and right ends of the left and right operation path 19 to the forward operation path 20 or the reverse operation path 21, the continuously variable transmission is operated from the neutral position N1 to the high speed side.

0003

[Problem to be Solved by the Invention] In the configuration shown in FIG. 8, for example, from the state where the shift lever 1 is operated to the forward operation path 20, the left end of the left and right operation path 19 (lower end in the page) is moved to the right in the page. Suppose that the operation is performed to return to . in this case,
Even if the forward/reverse switching device is operated to the forward side F, the continuously variable transmission will be operated to the neutral position N1, so the transmission should be cut off and the aircraft should be temporarily stopped. However, if a mechanical error occurs in the linkage system from the shift lever 1 to the continuously variable transmission, this error may occur even though the shift lever 1 is operated to the position corresponding to the neutral position N1 of the left and right operation path 19. As a result, a situation may arise in which the continuously variable transmission itself does not return to a neutral state, and the aircraft may move forward at a slow speed without stopping. This is because in belt-type or tapered-cone continuously variable transmissions using split pulleys, the range corresponding to the neutral position is relatively narrow, and if the transmission deviates even slightly from the neutral position, power will flow. Therefore, if even a small amount of power is flowing in this way, in the case of a gear shift type forward/reverse switching device, a certain amount of surface pressure will remain on the occlusal surfaces of the switching shift gear and the forward gear that are interlocking with each other. Therefore, even if you try to operate the shift lever from the left end of the left-right operation path 19 to the neutral position N2 of the forward/reverse switching device, the shift gear will be difficult to disengage from the forward gear due to the above-mentioned surface pressure, making it difficult to operate the shift lever. It becomes something. SUMMARY OF THE INVENTION An object of the present invention is to provide a structure in which a shift lever that has been operated to the forward or reverse side can be easily operated when returning it to the neutral position of the forward/reverse switching device.

0004

[Means for Solving the Problems] The feature of the present invention is that the shift operation structure for a work vehicle as described above is configured as follows. In other words, [1] When the gear shift lever is operated to the left and right ends along the left and right operation path corresponding to the neutral position of the continuously variable transmission, the forward/reverse switching device is switched to the forward or reverse side. A forward operation path that mechanically interlocks and connects the speed change lever and a forward/reverse switching device, and extends forward from one end of the left and right operation path, and a reverse operation path that extends rearward from the other end of the left and right operation path. When the gear shift lever is operated along the forward or reverse operation path, the continuously variable transmission is operated from the neutral position to the high speed side while the forward/reverse switching device is switched to the forward or reverse side. To be,
The speed change lever and the continuously variable transmission are mechanically interlocked and connected, and at one of the left and right forward end or the reverse end of the left and right operation path, there is a device opposite to the forward or reverse operation path. An auxiliary path is provided to allow operation of the gear shift lever in the direction. [2] The portion of the auxiliary path in the previous item [1] on the center side of the left and right operation paths is formed into an inclined surface that is inclined with respect to the left and right operation paths in plan view.

[0005]

[Operation] When configured as in the previous section [1], for example, Fig.
Assume that when moving forward with the gear shift lever 1 positioned within the forward operation path 20 as shown in FIG. In this case, if there is a mechanical error in the linkage system to the continuously variable transmission, the shift lever 1 may
Although it is operated to the position corresponding to the neutral position N1 of
There are cases where the continuously variable transmission itself does not return to the neutral state. Therefore, in such a case, after returning the shift lever 1 to the left end of the left and right operation path 19, the shift lever 1 is operated until it enters the auxiliary path 23. In this way, even if the above-mentioned mechanical error occurs, the continuously variable transmission will be operated to the neutral position N1 side more than this error is taken into account, so the continuously variable transmission itself will be operated to the neutral position N1 side. It will definitely return it to a neutral state. After that, when the gear shift lever 1 is moved out of the auxiliary path 23 and operated to the neutral position N2 at the center of the left and right operation path 19, the shift gear of the forward/reverse switching device is resisted by the forward gear because the driving transmission system is stopped. This allows the gear shift lever 1 to shift to the neutral position N.
This means that the operation to 2 can be performed easily without being difficult. When configured as in the previous item [2], for example, when moving forward with the shift lever 1 positioned in the forward operation path 20, the shift lever 1 is moved from the left and right operation path 1 as described above.
Assume that the user operates to the auxiliary route 23 from the left end of 9. Thereafter, for example, as shown in FIG.
When returning from the position to the center side (neutral position N2 side) of the left and right operation path 20, the shift lever 1 can be operated smoothly along the inclined surface 23a.

[0006]

Effects of the Invention: By providing an auxiliary path that absorbs errors in the linkage system and reliably returns the continuously variable transmission to the neutral state as claimed in claim 1, it is possible to move the gear shift lever from the forward or reverse side. The forward/reverse switching device can now be easily moved to the neutral position, improving shift operability. Further, with the configuration as claimed in claim 2, when the gear shift lever is operated into the auxiliary path and then operated to the neutral position of the forward/reverse switching device, smooth operation can be performed along the slope, so that the gear shift is further facilitated. It is possible to improve operability.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. In the walk-behind binder, which is one of the working vehicles shown in Fig. 6, Figs. 2, 3, and 4 show the structure near the gear shift lever 1, in which the cylindrical member 2 is rotatable around the axis P1. At the same time, the gear shift lever 1 is supported around the axis P2 of the cylindrical member 2 so as to be swingable.

Another cylindrical member 5 is rotatably supported around the axis P1, and a first operating arm 3 having an L-shape in front view is fixed to this cylindrical member 5. The upper end of the first operating arm 3 has a recess 3 into which the gear shift lever 1 can fit.
A is provided, and the continuously variable transmission device 25 for traveling shown in FIG. 6 and the first operating arm 3 are interlocked and connected by a linking rod 4 or the like. As shown in FIG.
It is equipped with a tapered cone. A ball-type detent mechanism 6 is provided to hold the first operating arm 3 at a neutral position N1 of the continuously variable transmission 25 shown in FIG.

On the opposite side of the first operating arm 3, another cylindrical member 7 is rotatably supported around the axis P1, and a second operating arm 8 is fixed to this cylindrical member 7. . A recess 8a into which the gear shift lever 1 can be inserted is provided at the upper end of the second operating arm 8, and a ball holds the second operating arm 8 at the neutral position N1 of the continuously variable transmission 25 shown in FIG. A detent mechanism 6 of the type is provided.

[0010] Then, a support shaft 9 is attached around the axis P3 at a different position.
is rotatably supported, and the first arm 1 is attached to the support shaft 9.
0 is fixed. On the other hand, a pin 11 with a roller 11a is fixed to the second operating arm 8, and this pin 1
1 is inserted into the long hole 10a of the first arm 10. Furthermore, a linking member 13 is constructed and connected across the second arm 12 fixed to the support shaft 9 and the first operating arm 3.

A support shaft 15 is rotatably supported around the axis P4 of the lever guide 14, and an operation arm 16 fixed to the lower part of the support shaft 15 is linked with a forward/reverse switching device 26 shown in FIG. They are interlocked and connected by a rod 17 or the like. This forward/reverse switching device 26 slides a shift gear (not shown) to shift it to a protrusion on the side of the forward gear (not shown) or a protrusion on the side of the reverse gear (not shown). It is a gear shift type that switches between forward and backward movement by engaging the gear. An operating section 18 is fixed to the upper part of the support shaft 15. As shown in FIG. 1, this operating portion 18 is provided with a U-shaped recess 18a, and arm portions 18b and 18c extend from the left and right sides of this recess 18a.

Next, the operating path of the gear shift lever 1 will be explained. As shown in FIG. 1, a left-right operation path 19 is formed in the lever guide 14 along the left-right direction of the aircraft (vertical direction in the drawing), and this left-right operation path 19 is connected to the continuously variable transmission 2.
5 corresponds to the neutral position N1 of
The operating arms 3 and 8 are set to the neutral position N1 by the detent mechanism 6.
is maintained. A forward side operation path 20 extends from the left end of the left and right operation path 19 (lower end in the page) to the front of the aircraft (left side in the page).
is opened, and the right end of the left and right operation path 19 (upper end of the page)
A reverse operation path 21 is opened at the rear of the aircraft (to the right in the paper).

The state shown in FIGS. 1 to 4 is a state in which the shift lever 1 is operated to the left and right center of the left and right operation path 19, and the shift lever 1 is located at the neutral position N1 of the continuously variable transmission 25, and the shift lever 1 is operated in the center of the left and right operation path 19. The operating portion 18 of the switching device 26 is also located at the neutral position N2. Then, from the state shown in Fig. 1, shift lever 1
When you operate the shift lever 1 to the left (downward on the page), the shift lever 1 shifts to the first position.
While engaging the concave portion 3a of the operating arm 3 (the continuously variable transmission 25 is in the neutral position N1), the operating portion 18 is operated to the forward side F in conjunction with the shift lever 1. In this state, shift lever 1
When the is operated forward (to the left in the paper) along the forward operation path 20, the first operating arm 3 is swung counterclockwise in FIG. 2, and the continuously variable transmission 25 is operated to the high speed side. I'm going to be done.

In this case, in the forward operation path 20, the length of the forward operation path 20 is approximately the entire length of the operation section 1.
8, and the forward/reverse switching device 26 is biased toward the neutral position N2, so the shift lever 1 is moved forward along the forward operation path 20 (toward the left in the paper) in FIG. When the arm portion 18b is operated, the arm portion 18b comes into contact with the shift lever 1 and is held. As a result, the operating portion 18 and the forward/reverse switching device 26 are held on the forward side F. Furthermore, as shown in FIGS. 2 and 4, a plurality of holes 3b and 8b into which the detent mechanism 6 can be inserted are provided on the side surfaces of the first and second operating arms 3 and 8, and the holes 3b and 8b are provided in the high speed range. The structure is such that the first or second operating arms 3, 8 can be easily held at a predetermined shift position within the gear shift position.

Next, from the state shown in FIG. 1, when the shift lever 1 is operated to the right (upward in the paper) along the left-right operating path 19, the shift lever 1 engages in the recess 8a of the second operating arm 8 and ( The continuously variable transmission 25 is in a neutral position N1), and the operating portion 18 is operated to the reverse side R in conjunction with the shift lever 1. Then, when the gear shift lever 1 is operated backward (to the right in the paper) along the reverse operation path 21, the support shaft 9 is rotated counterclockwise in FIG. 2 by the operation of the second operation arm 8. Then, the first operating arm 3 is swung in the counterclockwise direction in FIG. 2 in the same way as when moving forward. As a result, the continuously variable transmission 25 is operated to the high speed side.

As shown in FIG. 1, a concave-shaped auxiliary path 23 is provided at both left and right ends of the left and right operation path 19 (upper and lower ends in the drawing) in a direction opposite to each of the forward and reverse operation paths 20 and 21. ing. For example, when moving forward with the speed change lever 1 positioned within the forward operation path 20, assume that the speed change lever 1 is returned to the left end of the left and right operation path 19 (lower end in the drawing). In this case, even if the forward/reverse switching device 26 is operated to the forward side F, the continuously variable transmission 25
is operated to the neutral position N1, so the aircraft should stop temporarily.

However, if a mechanical error occurs in the linkage system from the linkage rod 4 to the continuously variable transmission 25, the shift lever 1 may be operated to a position corresponding to the neutral position N1 of the left and right operation path 19. However, it appears that the continuously variable transmission 25 itself has not returned to the neutral state. This causes the aircraft to move forward at a slow speed without stopping. Therefore, in such a case, after returning the shift lever 1 to the left end of the left-right operation path 19 (bottom end in the drawing), operate the shift lever 1 until it enters the auxiliary path 23. In this way, even if the above-mentioned mechanical error occurs, the continuously variable transmission 25 will be operated toward the neutral position N1 more than when this error is taken into consideration.
5 itself will definitely be returned to a neutral state. after that,
Take out the gear shift lever 1 from the auxiliary path 23 and move it to the left/right operation path 1.
9, the shift gear of the forward/reverse switching device 26 is smoothly disengaged from the forward gear with little resistance because the driving transmission system is stopped.

In the above-mentioned state, when the shift lever 1 located at the neutral position N2 of the left and right operation path 19 is operated to the forward operation path 20, the shift lever 1 is moved to the neutral position of the left and right operation path 19 as described above. There are cases where the continuously variable transmission 25 itself has not returned to the neutral state even though it has been operated to the position corresponding to N1. In this case, since a small amount of power is flowing through the driving transmission system, the shift gear or the forward gear in the forward/reverse switching device 26 is rotating at a low speed. Therefore, when operating the shift lever 1 located at the neutral position N2 of the left/right operation path 19 to the forward side F, even if the shift gear of the forward/reverse switching device 26 and the forward gear are not in phase, By rotating the shift gear or forward gear, the phases match and the two mesh smoothly.

The operation state of the shift lever 1 described above occurs in the same manner when the shift lever 1 is returned from the reverse operating path 21 to the left/right operating path 19.

As shown in FIG. 5, a clutch arm 28 for operating a reaping clutch (not shown) that turns on/off power transmission to the reaping section 27 and a binding device (not shown), and an operating arm 29 at the front of the machine. are mechanically interlocked and connected to the linking rod 30. When the reaping clutch lever 31 for the clutch arm 28 is operated to the automatic position, when the operating arm 29 hits the grain culm and swings backward at the start of reaping work, the clutch arm 28 is automatically operated to the engaged position. It is configured so that In this case, a linking rod 32 extends from the speed change operation part 25a of the continuously variable transmission 25 and is linked to a check arm 33,
5 is configured to prevent the clutch arm 28 from being operated to the engaged position by the check arm 33 when the clutch arm 28 is in an extremely low speed state from a neutral state to a predetermined position.

[Another Embodiment] As shown in FIG. 7, the surface of the left and right auxiliary paths 23 on the neutral position N2 side may be formed into an inclined surface 23a that is inclined with respect to the left and right operation path 19. With this, for example, when moving forward with the gear shift lever 1 positioned in the forward operation path 20, when operating the gear shift lever 1 back to the left/right operation route 19, the shift lever 1 is placed in the auxiliary route 23 and then the left/right operation is performed. When returning to the center side of the path 19, the shift lever 1 can be operated smoothly along the inclined surface 23a. In the embodiment described above, the auxiliary path 23 was provided at both the left and right ends of the left and right operation path 19 as shown in FIGS. 1 and 7, but the auxiliary path 23 was provided only on the forward side F or the reverse side R of the left and right operation path 19. It's okay.

[0022] Although reference numerals are written in the claims for convenience of comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

[Fig. 1] Plan view showing the gear shift lever, left and right operation paths, forward side and reverse side operation paths

[Figure 2] Side view of the vicinity of the base of the gear shift lever

[Figure 3] Rear view near the base of the gear shift lever

[Figure 4] Plan view of the vicinity of the base of the gear shift lever

[Fig. 5] A schematic side view showing the interlocking state of the clutch arm for operating the reaping clutch, the reaping clutch lever, the continuously variable transmission for traveling, etc.

[Figure 6] Overall side view of binder

[Fig. 7] Shift lever, left and right operation path in another embodiment,
Plan view showing forward and reverse side operation paths

[Fig. 8] A plan view showing a conventional gear shift lever, left and right operation paths, and forward and reverse side operation paths.

[Explanation of symbols]

1 Gear shift lever 19 Left and right operation path 20 Forward side operation path 21 Reverse side operation path 23 Auxiliary path 23a Slope of auxiliary path 25 Continuously variable transmission for traveling 26 Forward/forward switching device N1 Neutral position of continuously variable transmission for traveling F
Forward side R Reverse side

Claims (2)

[Claims] 1. A speed change operation structure for a work vehicle in which a continuously variable transmission (25) for traveling and a gear shift type forward/reverse switching device (26) are arranged in series, When the gear shift lever (1) is operated to the left and right ends along the left and right operation path (19) corresponding to the neutral position (N1) of
) or the reverse side (R), the speed change lever (1) and the forward/reverse switching device (26) are mechanically interlocked and connected, and from one end of the left/right operation path (19). A forward side operation path (20) extending forward and a reverse side operation path (21) extending rearward from the other end of the left and right operation path (19) are provided, so that the speed change lever (1) can be moved to the forward side or When operated along the reverse operation paths (20) and (21), the forward/reverse switching device (26) changes to the forward side (
The speed change lever (1) and the continuously variable transmission are arranged so that the continuously variable transmission (25) is operated from the neutral position (N1) to the high speed side when the gear is switched to the reverse side (R) or the reverse side (R). (25), and the forward side or A shift operation structure for a working vehicle, which is provided with an auxiliary path (23) that allows operation of the shift lever (1) in a direction opposite to the reverse side operation paths (20) and (21). 2. A central portion of the left and right operation path (19) in the auxiliary path (23) is formed into an inclined surface (23a) that is inclined with respect to the left and right operation path (19) in plan view. 1. A speed change operation structure for the work vehicle described in 1.