JP2519812B2 - Work vehicle traveling operation structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a work vehicle such as a walk-type work vehicle or a riding-type rice transplanter, and more specifically, it is operated by an operation tool that can be held at an arbitrary operation position. The present invention relates to a traveling operation structure of a work vehicle including a continuously variable transmission for traveling and a main clutch.

[Conventional technology]

Conventionally, as shown in Japanese Patent Application No. 1-231871 previously filed by the present applicant, the manual operation for the continuously variable transmission for traveling is interlocked with the disengagement operation of the main clutch for traveling. A running mechanism of a working vehicle that is provided with a holding mechanism for forcibly returning the tool to the neutral stop position and holding and fixing the tool, and is linked so that the holding action of the holding mechanism is released by the engagement operation of the main clutch. A structure has been proposed.

In this proposed technology, when the vehicle is started again after stopping traveling, the main clutch is engaged and then the continuously variable transmission that is in the neutral position is operated to change gears. The condition was obtained.

[Problems to be Solved by the Invention]

However, in the above-mentioned conventional technique, it is necessary to perform a gear shift operation every time the vehicle starts from a stop, and it is difficult to operate the gear shift operation lever to match the traveling speed before the stop again after the stop because of the continuously variable shift. In particular, the above operation is troublesome when a skilled worker wants to work efficiently at a constant speed.

 An object of the present invention is to eliminate the above disadvantages.

[Means for solving the problem]

The present invention that achieves the above-mentioned object, in the traveling operation structure of a work vehicle described at the beginning, enables forward and reverse operation of the operation lever of the main clutch in the order of a clutch engaged position, a first clutch disengaged position, and a second clutch disengaged position. In addition to the above, a neutral return mechanism for forcibly returning the operating tool from an arbitrary gear shift position to a neutral position is provided, and only the main clutch is disengaged at the first clutch disengagement position of the operation lever, and the second clutch disengagement operation is performed. In the position, the neutral return mechanism is operated in the main clutch disengaged state.

[Work]

According to the above configuration, between the "engagement" and the "disengagement" of the main clutch in the related art, "disengagement" in which only the main clutch is disengaged and does not interfere with the continuously variable transmission can appear. If the operating lever is operated to stop at the clutch disengaged position, the set speed of the continuously variable transmission does not change.Therefore, the operating lever can be operated again to obtain the same running condition as before stopping. There is no need to shift gears each time.

Then, if the operating lever is operated past the first clutch disengaged position to the second clutch disengaged position, the continuously variable transmission is automatically brought into a neutral state, and the operation lever is operated from the second clutch position to the clutch engaged position. If you do so, you will be able to obtain a smooth restart from a low speed.

That is, since the first clutch disengagement position is set between the clutch engaged position and the second clutch disengagement position, the state where only the main clutch is disengaged regardless of the continuously variable transmission and the continuously variable transmission as in the prior art are used. It is possible to arbitrarily use the main clutch disengaged state after returning to neutral.

〔The invention's effect〕

Therefore, it is possible to select a smooth start state in which the vehicle restarts normally after a stop from a low speed as usual, and an efficient start state in which the set traveling speed can always be maintained regardless of the stop and the gear shift operation is unnecessary. Therefore, for example, a skilled worker can use the first clutch disengaged position to achieve good work efficiency, and an unskilled worker can use the second clutch disengaged position to smoothly start the operation. It was possible to provide a convenient traveling operation structure in which both states can be selectively used according to the usage situation, such as selection.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 7, a frame (2) is extended rearward from the mission case (1), an engine (3) is mounted on the frame (2), and a pair of left and right parts are installed at the bottom of the mission case (1). Wheels (4), a steering handle (5) on the upper part of the mission case (1), and a rotary mower (6) on the front part of the mission case (1),
A walk-behind work vehicle, which is an example of a work vehicle, is configured.

Next, the transmission structure from the engine (3) to the mission case (1) will be described. As shown in FIG. 7, the output side (7) projects from the front surface of the engine (3) to the mission case (1) side, and the output shaft (7) has a first output pulley (8) and a second output. A pulley (9) is attached. On the other hand, the input shaft (10) of the PTO system is pierced and supported in the lower part of the mission case (1) in the front-rear direction, and the input pulley (11) is provided at the end of the input shaft (10) on the engine (3) side. ) Is attached, and two transmission belts (12) are wound around the second output pulley (9) of the output shaft (7) of the engine (3) and the input pulley (11).

In the input shaft (10) of the PTO system, a slidable engagement part (13) having a spline structure is attached to an end opposite to the engine (3), and an input pulley is provided on the engine (3) side. (11) and input shaft (10)
A multi-plate friction clutch (14) is provided between and.

 Next, the transmission structure of the traveling system will be described in detail.

As shown in FIGS. 6 and 7, a hydrostatic continuously variable transmission (15) (hereinafter, abbreviated as HST), which is an example of the continuously variable transmission, is provided on the engine (3) side portion of the mission case (1). It is attached, and the input shaft (16) of this HST (15) projects to the engine (3) side. The transmission belt (18) is wound around the input pulley (17) attached to the input shaft (16) and the first output pulley (8) of the output shaft (7) of the engine (3). ing. Further, a tension pulley (19) for transmission on / off is arranged on the transmission belt (18) to form a main clutch (C).

Next, the relationship between the operation system of the main clutch (C) and the operation system of the HST (15) will be described in detail. As shown in FIGS. 4, 5 and 6, the operating lever (20) of the gate-type main clutch is swingably supported around the horizontal axis (P ₁ ) of the steering handle (5). The tension pulley (19) and the operating lever (20) are interlockingly connected via a wire (21), and the swinging operation of the operating lever (20) causes the tension pulley (19) to be displaced and transmitted. The belt (18) is tensioned and relaxed, and power is turned on and off from the engine (3) to the HST (15).

As shown in FIG. 3, the rotation shaft (23) is supported rotatably around the horizontal axis (P ₂ ) with respect to the boss member (22), and the outside of the rotation shaft (23) is also supported. An operation tool (24) made of a leaf spring and serving as a speed change lever is fixed to the end. Then, the operating tool (24) and the operating portion (not shown) of the HST (15) are
The gears are interlocked and coupled via a push-pull wire (25), and a gear shift operation is possible between a forward drive position (F) and a reverse drive position (R) with a neutral stop position (N) in between.

The operation tool (24) has a rotary shaft (23) with a disc spring (2).
It is configured so that it can be held at any operating position by constantly pressing and urging it laterally by 6).

The operation lever of the main clutch is configured to be operable in the order of the clutch engaged position, the first clutch disengaged position, and the second clutch disengaged position, and the operation tool is forcibly moved from an arbitrary shift position to a neutral position. A neutral return mechanism for returning is provided, and only the main clutch is disengaged at the first clutch disengaged position of the operation lever, and the neutral return mechanism is operated at the main clutch disengaged state at the second clutch disengaged position. is there.

As shown in FIGS. 1 and 2, a holding plate (28) is bolted in a flat plate shape to a bracket plate (27) fixed to the rotating shaft (23) having a hexagonal cross section. Board (28)
Rollers (29) rotatable around the horizontal axis in the upper and lower parts,
(29) is attached to form the neutral return mechanism (A), and the left vertical pipe portion (20a) of the operation lever (20) can contact the rollers (29) and (29) in the front-rear direction. It is arranged to be. As a result, the operation lever (20) is moved from the clutch engaged position (I) to the first position while the operation tool (24) is operated to the forward drive position (F) or the reverse drive position (R).
When the clutch plate is moved past the clutch disengagement position (K ₁ ) to the second clutch disengagement position (K ₂ ), the holding plate (28) is in the posture shown by the solid line or the one-dot chain line as shown in FIG.
The vertical pipe portion (20a) of the operation lever (20) contacts the roller (29) on the upper side or the lower side, and the holding plate (28) is pushed back to the posture (neutral position) shown in FIG. Therefore, the operating tool (24) is returned to the neutral position (N) and the HST (15) stops. Then, since the operation lever (20) presses the holding plate (28) with the roller (29) from above, the operation lever (2)
The operation tool (24) cannot be operated unless the 0) is operated toward the entry position (I).

Move the operating lever (20) to the first clutch disengagement position (K ₁ ).
When the operation tool (24) is operated at any position, the rollers (29), (29) and the left vertical pipe section (20a) are set so as not to interfere with each other regardless of the position of the operation tool (24), and the main clutch ( Only C) is cut off.

In other words, the first clutch disengagement position is the position where the vertical pipe (20a) comes into contact with either the upper or lower roller (29) for the first time.

Further, (30) is a PTO lever for turning on and off the friction clutch (14), and (31) is the input shaft (10) of the PTO system.
It is a forward / reverse lever that reverses the rotation of.

The present invention can be applied to a riding type tractor, a rice transplanter, and the like.

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 structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a traveling operation structure of a work vehicle according to the present invention. FIG. 1 is a side view showing a positional relationship with an operation lever when an operation tool is neutral, and FIG. 2 is a first clutch of the operation lever. A side view showing a state of a cutting position, FIG. 3 is a sectional front view showing a structure of an operating tool, FIG. 4 is a side view showing an operating state of an operating lever, and FIG. 5 is a plan view showing a steering section of a handle. Sixth
FIG. 7 is a diagram of a main part showing a main clutch, and FIG. 7 is an overall side view of a walking work vehicle with a rotary mower. (15) …… continuously variable transmission, (20) …… operating lever, (2
4) …… Operating tool, (A) …… Neutral return mechanism, (C) ……
Main clutch, (I) …… Clutch engagement position, (K ₁ ) ……
1st clutch disengaged position, (K ₂ ) ... 2nd clutch disengaged position, (N) ... neutral position.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tokio Horikawa 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Iron Works Co., Ltd. Sakai Works

Claims (1)

(57) [Claims] 1. An operating tool (24) capable of being held at an arbitrary operating position.
A traveling operation structure of a working vehicle comprising a continuously variable transmission (15) for traveling operated by a vehicle and a main clutch (C), wherein an operation lever (20) of the main clutch (C) is engaged. The position (I), the first clutch disengagement position (K ₁ ) and the second clutch disengagement position (K ₂ ) are configured in such a manner that they can be operated in the forward and reverse directions, and the operation tool (24) is forcibly operated from an arbitrary gear shift position. Neutral return mechanism (A) to return to the neutral position (N)
Is provided, and only the main clutch (C) is disengaged at the first clutch disengagement position (K ₁ ) of the operation lever (20),
A traveling operation structure for a work vehicle configured such that the neutral return mechanism (A) is operated in the main clutch disengaged state at the second clutch disengaged position (K ₂ ).