JPH08300967A - Transmission of working traveling vehicle - Google Patents

Abstract

PURPOSE: To reduce the operating labor, and to enable the rapid transmission by operating a traveling transmission mechanism and a forward/rearward switching mechanism by a same transmission lever, and simplifying the transmission as a result. CONSTITUTION: Traveling transmission mechanisms (a main transmission mechanism 6, and a sub transmission mechanism 9), and a forward/rearward switching mechanism 8 are connected to one transmission lever 24. When the transmission lever 24 is operated in the longitudinal direction, the main transmission mechanism 6 and the sub transmission mechanism 9 are gear-changed. When the transmission lever 24 is operated from each traveling transmission position to one side, the forward/rearward switching mechanism 8 is switched in the condition where the transmission position of the main transmission mechanism 6 and the sub transmission mechanism 9 is fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a work vehicle such as a tractor.

[0002]

BACKGROUND OF THE INVENTION Generally,
In this type of work vehicle, a traveling speed change mechanism for changing the traveling power and a forward / reverse switching mechanism for switching the traveling power between the forward and reverse directions are independently configured to perform multi-stage traveling speed change in any of the forward and reverse states. There are things you can do.
However, in the prior art, since the traveling transmission mechanism and the forward / reverse switching mechanism are configured to be operated by separate levers, for example, when shifting from a high speed forward drive state to a low speed reverse drive state, two levers are used. In reality, it is difficult to perform a speed change operation, although it may be inferior in operability because it needs to be operated sequentially.

[0003]

SUMMARY OF THE INVENTION The present invention was conceived in view of the above circumstances and was devised with the object of providing a transmission system for a working vehicle capable of overcoming these problems. , A traveling speed change mechanism for changing the traveling power,
In a work vehicle equipped with a forward / reverse switching mechanism for switching the traveling power between forward and reverse, the traveling transmission mechanism and the forward / reverse switching mechanism are linked to the same shift operation lever, and based on the forward / backward operation of the shift operation lever. The present invention is characterized in that a speed change actuating mechanism is provided which actuates the travel speed change mechanism while actuating the forward / reverse switching mechanism on the basis of lever operation from each travel speed change operation position to one side. With this configuration, the present invention makes it possible to operate the traveling speed change mechanism and the forward / reverse switching mechanism with the same speed change operation lever, and as a result, in addition to simplifying the speed change operation and reducing the operation labor,
This enables a speed change operation.

[0004]

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a traveling machine body of a tractor. The traveling machine body 1 is provided with an engine 2 at a front portion of the machine body, and a power generated by the engine 2 is transmitted to a drive wheel 4 and a PTO via a transmission 3 described later. Although it is configured to be transmitted to the shaft (work power take-out shaft) 5, the basic configuration of these is the same as that of the conventional one.

The transmission 3 includes an engine 2
The power input from is distributed to the traveling system and the PTO system, and the distributed traveling system power is distributed to the main transmission mechanism 6, the hydraulic clutch 7,
While being transmitted to the rear wheel differential mechanism 11 via the forward / reverse switching mechanism 8, the auxiliary transmission mechanism 9, and the ultra-low speed transmission mechanism 10, the distributed PTO system power is transmitted to the PTO transmission mechanism 12 and PTO.
Although it is configured to be transmitted to the PTO shaft 5 via the reverse rotation mechanism 13, since the synchromesh system (synchronous meshing system) is adopted for each speed change mechanism of the traveling system, the speed change gears provided in each speed change mechanism are adopted. A smooth and quick shift can be performed based on the front and rear slide operation of the sleeve.

Reference numerals 14 to 16 denote traveling speed shifters connected to the respective speed change sleeves of the main speed change mechanism 6 and the auxiliary speed change mechanism 9, and the operation of the speed change shifters 14 to 16 is controlled by a rotary valve 17. The first to third hydraulic cylinders 18 to 20 are connected to each other. That is, in the main transmission mechanism 6 and the auxiliary transmission mechanism 9 of the present embodiment, the hydraulic cylinders 18 to 20 associated with the switching operation of the rotary valve 17 are performed.
A so-called power shift system is adopted in which gear shifting is performed by the hydraulic operating force of 8 gears (main gear shifting 4 gears, sub gear shifting 2
However, since the above-mentioned hydraulic clutch 7 is connected to the rotary valve 17, the "disengagement" operation of the hydraulic clutch 7 at the time of gear shifting and the hydraulic clutch 7 after the gear shifting is completed are possible. The "ON" operation can be automatically performed.

Further, reference numeral 21 is a forward / reverse switching shifter connected to the speed change sleeve of the forward / backward switching mechanism 8, and the forward / backward switching shifter 21 is operated by a manual operation force. A position detection switch 22 that detects an operation position (forward / reverse switching position and neutral position) of the forward / reverse switching shifter 21 is connected to a shifter shaft forming the shifter 21. Then, when the position detection switch 22 detects the neutral position, the solenoid valve 23 provided between the hydraulic pump P and the rotary valve 17 is switched, and the hydraulic clutch 7 is activated by the pressure change caused by the switching. On the other hand, when the position detection switch 22 detects the forward / reverse switching position while automatically performing the "off" operation, the solenoid valve 23 is returned to the initial position so that the hydraulic clutch 7 is automatically turned on. Has become.

On the other hand, reference numeral 24 is a gear shift operating lever provided in the operating portion of the traveling machine body 1.
Is allowed to rotate in the front-rear direction about the first lever support shaft 25 as a fulcrum and rotate in the left and right direction about the second lever support shaft 26 as a fulcrum. That is, the first boss member 27, which is integrally provided at the base end portion of the gear shift operation lever 24, is supported by the second boss member 28 via the second lever support shaft 26 facing forward and backward, and the second boss member 28 is also supported. 28 is supported on the machine body side via a first lever support shaft 25 facing left and right. When the shift operation lever 24 is operated in the front-rear direction, the above-mentioned rotary valve 17 linked via the link mechanism 29 is switched, and the travel shift corresponding to the switching position is performed. . Reference numeral 30 is a torsion spring for restraining the free rotation of the first boss member 27 with respect to the second boss member 28.

Further, reference numeral 31 is a guide plate facing the front-rear direction in the lateral direction of the base end portion of the gear shift operation lever 24 and closely facing the guide end plate. The guide plate 31 is provided at the base end portion of the gear shift operation lever 24 so as to project therefrom. The guide pin 32 is guided by the elongated hole 31a having an arc shape (the center of the arc is the first lever support shaft 25), but when the gear shift operation lever 24 is operated in the left-right direction, the lever operation is followed. It is slidably supported by a pair of front and rear guide rails 33 so as to be displaced in the left-right direction. When the guide plate 31 is displaced to the left or right, the forward / reverse switching shifter 21 linked via the connecting wire (push-pull wire) 34 is interlocked, and the forward / backward switching corresponding to the shifter position is performed. It has become.

Furthermore, 35 is a lever guide of the gear shift operation lever 24. The lever guide 35 is formed with a traveling gear shift guide groove 35a facing the front-rear direction to guide the traveling gear shift operation, and Corresponding displays (N, 1 to 8) are provided at the traveling gear shift operation positions,
Further, the forward / reverse switching guide grooves 35b facing the right and left directions are provided at the respective traveling speed change operation positions of the traveling speed change guide groove 35a.
Is extended toward one side. That is, lever operation to one side at each traveling gear shift operation position (forward / reverse switching operation)
In order to allow the
It is possible to perform a shift operation of 8 speeds and reverse speed.

In the embodiment of the present invention configured as described above, the gear shifts of 8 forward speeds and 8 reverse speeds can be performed by operating the main transmission mechanism 6, the auxiliary transmission mechanism 9 and the forward / reverse switching mechanism 8 provided in the transmission 3. However, the main transmission mechanism 6,
The sub-transmission mechanism 9 and the forward / reverse switching mechanism 8 are linked to a single shift operation lever 24. When the gear shift operation lever 24 is operated in the front-rear direction, the main gear change mechanism 6 and the sub gear change mechanism 9 are gear-shifted, while when the gear change operation lever 24 is operated one side from each traveling gear shift operation position. Means that the forward / reverse switching mechanism 8 is switched while the shift positions of the main transmission mechanism 6 and the auxiliary transmission mechanism 9 are fixed. Therefore, it is not necessary to operate two levers as in the prior art in which the traveling speed change mechanism (main speed change mechanism 6 and auxiliary speed change mechanism 9) and the forward / reverse switching mechanism 8 are operated by separate levers, and operability is improved. Perhaps it can be improved, but a speed change operation can be enabled as compared with the case of operating two levers in sequence.

In addition, since the two levers are integrated into one, there are advantages that the number of parts can be reduced, the structure can be simplified, the cost can be reduced, and the lever arrangement can be facilitated.

Further, since the forward / reverse switching is performed based on the lever operation to one side, the forward / reverse switching operation function can be added without particularly extending the operation stroke of the existing traveling speed change lever in the front-rear direction. There is an advantage.

[0014]

In summary, since the present invention is constructed as described above, it is provided with the traveling speed change mechanism for changing the traveling power and the forward / reverse switching mechanism for switching the traveling power between the forward and reverse directions. The traveling speed change mechanism and the forward / reverse switching mechanism are connected to the same speed change operation lever, and when the speed change operation lever is operated in the front-rear direction, the speed change operation mechanism is operated, while the speed change operation lever is moved from each of the speed change operation positions. Since the forward / reverse traveling switching mechanism is operated when operated to one side, it is possible to operate the traveling transmission mechanism and the forward / reverse traveling switching mechanism with one shift operation lever.
Therefore, it is not necessary to sequentially operate the two levers as in the conventional case in which the traveling speed change mechanism and the forward / reverse switching mechanism are operated by separate levers. As a result, the operation can be simplified and the operation labor can be reduced. It is possible to enable a quick shift operation.

[Brief description of drawings]

FIG. 1 is a side view of a tractor.

FIG. 2 is an explanatory diagram showing a schematic configuration of the entire transmission mechanism.

FIG. 3 is a side view of a shift operation lever.

FIG. 4 is a side view of the main part of the same.

FIG. 5 is a rear view of the main part of the same.

FIG. 6 is a plan view of a lever guide.

[Explanation of symbols]

 1 traveling machine body 3 transmission 6 main transmission mechanism 7 hydraulic clutch 8 forward / reverse switching mechanism 9 auxiliary transmission mechanism 24 shift operation lever 29 link mechanism 31 guide plate 34 connecting wire

Claims (1)

[Claims] 1. In a work vehicle equipped with a traveling speed change mechanism for changing traveling power and a forward / reverse switching mechanism for switching traveling power between forward and reverse, the traveling speed change mechanism and the forward / backward change mechanism have the same speed change lever. And a gear shift operating mechanism for operating the traveling gear shift mechanism based on the forward / backward operation of the gear shift operating lever and operating the forward / reverse switching mechanism based on the lever operation from each traveling gear shift operation position to one side. A transmission for a traveling vehicle for work, characterized by being provided.