JPH0620831B2 - Shifting structure of work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is configured to easily perform a multi-stage gear shift operation by operating an actuator based on forward / reverse operation in a certain direction in a multi-stage gear shift operation by a shift lever. The present invention relates to a shift operation structure of a working vehicle.

[Conventional technology]

Since such a shift lever can be operated by forward / reverse operation in a constant direction in which the shift lever is linearly operated, the operation thereof is simple and the operation of the transmission device is configured to shift gears via an actuator. Therefore, the operation is light and easy to handle. By the way, as the shape of the guide groove for guiding the gear shift lever, a linear shape in which a plurality of gear shift positions are continuously provided from a neutral position to a high speed has been conventionally proposed.

[Problems to be Solved by the Invention]

However, with the linear guide groove, the high-speed lever can be operated linearly forward and backward along the guide groove, so that there is an advantage that it is easy to operate, while a desired gear shift position is skipped during a gear shift operation. There is a case where the vehicle is switched due to a sudden start, acceleration, deceleration or deceleration.

As a solution to the above drawbacks, a stepped guide groove that is bent at each shift position of the shift lever is also proposed, but the guide groove of this structure does not have a straight line portion having a plurality of shift positions. It has the advantage that the gearshift lever does not jump over the desired gearshift position and can be switched reliably and safely, but it is necessary to bend the gearshift lever for each gearshift position. It had the drawback of being very bad.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a gear shift operation structure for a work vehicle that is safe and that can perform a switching operation with good operability.

[Means for Solving the Problems]

The technical means of the first aspect of the present invention, which has been implemented to achieve the above object, is a gear shift operation structure for a work vehicle configured to operate an actuator based on a constant direction forward / reverse operation of a gear shift lever to perform multiple gear shifts. In the operation range of the guide groove for guiding the shift lever, a high speed shift range having a plurality of shift positions for road traveling or high speed work, and a plurality of shift positions suitable for performing work at a speed lower than this are provided. It is divided into a low speed shift range and a shift neutral range where the output from the shift position is cut off, and each of the high speed transmission and the low speed shift range thus divided is defined by a straight line portion formed of a linear groove portion. In addition to the above structure, these linear portions are connected by a bending portion provided between the linear portions to form the guide groove in a bending linear shape, and the guide groove is connected to the low speed shift range. Shifting at one end It is characterized in that is provided with Tatsuiki.

For the same purpose, in the technical means of the second aspect of the present invention, in the gear shift operation structure of the work vehicle, the operation range of the guide groove for guiding the gear shift lever is set to have a plurality of gear shift positions for road traveling or high speed work. The high-speed shift range, the low-speed shift range having a plurality of shift positions suitable for performing work at a lower speed than this, and the shift neutral range in which the output from the shift position is cut off, Each of the high speed shift range and the low speed shift range is formed by a straight line portion formed of a linear groove portion, and these straight line portions are connected by a bending portion provided between the straight line portions, The guide groove is formed in a bent line, and further, the transmission operated by the actuator includes a main transmission having a number of shift stages smaller than the number of shift stages in the entire shift range, and a sub-transmission capable of shifting to high and low two stages. Assembly with device Align is composed of, is characterized in that the auxiliary speed change device is configured to be switched height in the middle position of the shift range in the entire speed range.

Further, for the same purpose, in the third aspect of the present invention, in the gear shift operation structure of the work vehicle, a linear portion that constitutes a gear shift range in an operation range of a guide groove that guides the gear shift lever is provided
A straight part for a low speed zone having a plurality of shift positions in a speed range suitable for low speed work, and a straight part for a high speed zone having a plurality of shift positions in a speed range suitable for road running or high speed work , And a straight portion for a medium speed zone having a plurality of gear shift positions at intermediate speeds of each of the high and low zones, and each straight portion of the end and the start of adjacent straight portions. That is, the guide groove is formed in a continuous refraction line shape by continuing the refraction portion provided between the guide grooves.

[Work]

The effect of taking the above technical means is as follows.

That is, since each straight line portion of the guide groove is provided with a plurality of shift positions, the forward / reverse operation of the shift lever in each straight line portion enables light shifting in a partial range relative to the entire shift range. You can do it. Moreover, since the bending portion is provided between the adjacent straight portions, in order to switch from the straight portion in the low speed shift range to the straight portion in the high speed shift range or vice versa, once the shift lever is moved in the bend portion. It is necessary to operate in the direction of refraction. Therefore, it is possible to prevent the gear shift lever from being suddenly switched to the gear shift position of the straight line portion in the high speed gear shift range or the low speed gear shift range, which is unexpected by only performing the forward and reverse operations on one straight line portion.

Further, in the case where the transmission is configured by the combination of the main transmission and the auxiliary transmission as in the second aspect of the present invention, the entire transmission can be downsized for the required number of gears, but the transmission lever Since it is necessary to operate the auxiliary transmission in addition to the operation of the main transmission at a specific position within the gear shift operation range, if the guide groove is linear, the transmission of the transmission that follows the rapid movement of the gear shift lever It is difficult to operate. However, in the second aspect of the present invention, as described above, since the guide groove is formed in the bending line shape, time can be gained by the detouring operation when the gear shift lever passes through the bending portion, and the operation of the sub-transmission device is involved. It is easy to change gears smoothly.

Further, as in the third aspect of the present invention, a linear portion that constitutes a shift range in the operation range of the guide groove that guides the shift lever
A straight part for a low speed zone having a plurality of shift positions in a speed range suitable for low speed work, and a straight part for a high speed zone having a plurality of shift positions in a speed range suitable for road running or high speed work , The middle speed zone in the middle part of the operation range where the operation position is the most difficult to recognize by configuring with the straight part for the middle speed zone which has a plurality of shift positions at the middle speed of each of the high and low zones. This makes it easy to recognize, and it is easy to avoid performing a single operation from the high speed zone to the low speed zone or vice versa.

〔The invention's effect〕

Therefore, there is an advantage that the operability and safety of the shift lever for shifting the traveling speed in the constant traveling direction can be ensured by a simple configuration in which the shape of the guide groove is changed.

Further, as in the second aspect of the invention, even when operating the main transmission and the auxiliary transmission, there is an advantage that smooth gear shifting can be easily performed while following the movement of the shift lever.

Further, as in the third aspect of the present invention, by providing the medium speed zone in the middle portion of the guide groove, it becomes easy to recognize the operation range for each zone.

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

As shown in FIG. 5, a wheel (5), (4) is mounted on the front and rear, a control part (31) is provided in the center, and a lift for driving and ascending and descending the connected working device is provided at the rear part. The tractor shown as an example of the work vehicle is configured by providing the arm (32).

The traveling transmission system and drive system of the tractor are configured as follows.

As shown in FIGS. 3 and 4, the power from the engine (1) is passed through the main clutch (2) to the main transmission (A), the multi-plate hydraulic clutch (3), and the auxiliary transmission (B). , The forward / reverse switching device (C) is sequentially transmitted, and the power from the forward / reverse switching device (C) is transmitted to the differential device (4a) for the rear wheel (4), and also from the forward / reverse switching device (C). The traveling power transmission system is configured to transmit the branched power of the vehicle to the actuator (5a) for the front wheels (5), and the power transmitted through the main clutch (2) is transmitted to the transmission.
(6) A drive system for a four-wheel drive type agricultural truck is constructed by sequentially transmitting the one-way rotation clutch (7) to drive the external power take-off shaft (8).

The main transmission (A) is composed of two synchromesh type gear transmissions (9) and (10) and is capable of shifting in four stages.
Further, the sub-transmission device (B) and the forward / reverse switching device (C) are also of the synchromesh type.

As shown in FIGS. 3 and 4, the main transmission device (A) and the auxiliary transmission device (B) are respectively operated by two hydraulic cylinders (11), (12) and one hydraulic cylinder (13) for shift operation. These three hydraulic cylinders (11), (12), (13)
Operates by being supplied with pressure oil from the hydraulic pump (15) through the speed change valve (14) for traveling.

Further, the three hydraulic cylinders (11), (12), (13) have their operating parts configured as three-position switching valves, and when each is operated to a position other than neutral, pilot pressure is generated. It is configured to let.

By the way, the hydraulic cylinder (13) for the auxiliary transmission (B) can be operated only in two positions of the low speed operation position (L) and the high speed operation position (H), and the neutral position of the switching valve of the cylinder (13) is It works only during operation.

Further, the forward / reverse switching device (C) is a swing type operation lever (1
It is operated manually by 6) and a hydraulic valve (17) is inserted in this artificial operation system. That is, the hydraulic valve (17)
Is configured to generate pilot pressure when the forward / reverse switching device (C) is set to the forward operation position (F) or the reverse operation position (R).

The hydraulic clutch (3) is configured to transmit power when pressure oil is supplied, and the hydraulic pump (15) and the shift valve (14)
The pressure oil is supplied by the oil passage (19) branched from the oil passage (18) between and.

Further, the hydraulic clutch (3) includes a main transmission (A) and an auxiliary transmission.
(B) or the forward / reverse switching device (C), when the shift operation is performed, the clutch is automatically disengaged, and when the shift operation is completed, the clutch is automatically engaged again. The main clutch is configured to be operated
The gear can be changed without turning (2).

That is, in the oil passage (19), the pilot pressure from the valve mechanism (20) for pressure control, the hydraulic valve (17) and the three hydraulic cylinders (11), (12) and (13) respectively is used. An operated switching valve group (21) is interposed, and an accumulator (22) is provided in a branched manner.

Then, when the main transmission (A) is set in a state in which the vehicle body is traveling, the switching valve group (21) is in the communication state, and the hydraulic clutch
(3) is the main transmission (A), the auxiliary transmission (B), the forward / reverse switching device when the vehicle is traveling while the entry state is maintained.
When any one of (C) is switched, the pilot pressure from the switching operation system is reduced during the switching operation and the switching valve group (2
At the same time that (1) shuts off the pressure oil from the hydraulic pump (15), the hydraulic oil of the hydraulic clutch (3) is caused to flow into the drain oil passage (23) and the hydraulic clutch (3) is disengaged. Next, when the shift change operation is completed, the changeover valve group (21) is set to the communication state again,
Engage and operate the hydraulic clutch (3).

Next, a shift operation structure for the multi-stage transmission including the main transmission (A) and the auxiliary transmission (B) will be described.

As shown in FIG. 3, the operation arm (25) is fixed to the spool (24) of the speed change valve (14) constituted by a rotary valve, and the speed change gear is provided at the tip of the operation arm (25). The base end of the lever (26) is swingably attached, and by operating the speed change lever (26) forward and backward in a fixed direction, the spool (24) is rotated to switch the oil passage, thereby enabling the multi-speed shift. It is configured to sequentially switch the device from the neutral state (N) to the eighth speed state (F8).

The shape of the guide groove (27) for guiding the speed change lever (26) is
As shown in Fig. 1, the guide plate (28) has three straight lines (L
1), (L2), (L3) are parallel and adjacent straight line parts (L1), (L
2) The holes of (L3) are drilled by shifting in the longitudinal direction so that the ends of (L3) are arranged close to each other, and bent at right angles between the adjacent straight parts (L1), (L2) or (L2), (L3) The refracted parts (W1), (W2)
The linear portions (L1), (L2), and (L3) are formed by being continuously drilled.

Further, at the end of the guide groove (27) is formed a neutral part (N) formed in the same direction as the refraction parts (W1), (W2),
From the neutral part (N) side, the straight part (L1) for the low speed zone has a gear shift position in a speed range suitable for tilling work, and the gear shift position has a gear range in a speed range suitable for front loader work. The straight line portion for the medium speed zone (L2) and the straight line portion for the high speed zone (L3) having a shift position in the speed range suitable for road traveling (L1), ( L2) and (L3) are provided. And, of these three straight line parts (L1), (L2), (L3), the straight line part (L3) for the high speed zone having the high speed position of the sixth speed to the eighth speed is used for road running or high speed work. A straight part (L1) for a low speed zone having a low speed position of 1st to 3rd speed and a medium speed position having a medium speed position of 4th speed to 5th speed, which constitutes a high speed shift range having a plurality of shift positions. The zone straight line portion (L2) constitutes a low speed shift range having a plurality of shift positions suitable for performing work at a lower speed than the work in the high speed range.

The operation arm (25) and the shift lever (2) for the shift valve (14)
6) and the tip of the speed change lever (26) between
A return spring (29) for urging the (W1) and (W2) in the bending direction is interposed, and a neutral part (N) is provided with a safety switch (30). Also, as shown in FIG. 2, the main clutch is
The pedal (31) that operates (2) is also equipped with a safety switch (32), and the engine is started by the key switch (33) with the transmission lever (26) set to neutral and the main clutch (2) disengaged. The safety switches (30) and (32) are connected to the engine starting control circuit (35) so that the starting cell motor (34) can be operated.

[Another embodiment]

The position of the speed change lever (26) may be electrically detected to control the electrically operated actuators (11), (12), (13). Also, the shift lever (26) and shift valve (14)
May be linked via a link mechanism or a wire.

[Brief description of drawings]

1 is a perspective view of a guide groove and a gear shift lever portion, and FIG. 2 is a schematic view showing a connection between a safety switch and a main clutch.
FIG. 3 is a hydraulic circuit diagram of a gear shift operation system, FIG. 4 is a schematic diagram showing an operating system of power for the underbody, and FIG. 5 is an overall side view of an agricultural tractor. (11), (12), (13) …… actuator, (26) …… gear lever, (27) …… guide groove, (L1), (L2), (L3) …… straight part, (W
1), (W2) …… Refraction part.

Claims (3)

[Claims] 1. A shift operation of a working vehicle configured to operate actuators (11), (12), (13) based on forward / reverse operation of a shift lever (26) in a fixed direction to perform multiple shifts. In the structure, the operation range of the guide groove (27) for guiding the speed change lever (26) is set to a high speed range having a plurality of speed change positions for road traveling or high speed work, and work speeds lower than this range. It is divided into a low speed shift range having a plurality of shift positions suitable for performing and a shift neutral range where the output from the transmission is cut off, and each of the divided high speed shift range and low speed shift range is defined by a straight line. It is composed of linear parts (L1), (L2), (L3) consisting of a groove section, and these linear parts (L1), (L2), (L3) are each linear parts (L1), (L2 ), (L3) between the refraction part (W
1) and (W2), the guide groove (27) is formed in a bent line shape, and the shift neutral area is provided at one end of the guide groove (27) that is continuous with the low speed shift area. A structure for shifting gears of a work vehicle. 2. A shift operation of a working vehicle configured to operate actuators (11), (12), (13) based on forward / reverse operation of a shift lever (26) in a fixed direction to perform multiple shifts. In the structure, the operation range of the guide groove (27) for guiding the speed change lever (26) is set to a high speed range having a plurality of speed change positions for road traveling or high speed work, and work speeds lower than this range. It is divided into a low speed shift range having a plurality of shift positions suitable for carrying out a shift, and a shift neutral range where output from the transmission is cut off, and each of the divided high speed shift range and low speed shift range is linearly divided. The straight part (L1), (L2), (L3) consisting of the groove part of, and these straight parts (L1), (L2), (L3), each straight part (L1), (L2) , (L3) Refraction part provided between them
(W1), (W2) in a continuous manner, the guide groove (27) is formed in a bent line shape, further, the transmission operated by the actuator (11), (12), (13) It is composed of a main transmission (A) having a number of gears smaller than the number of gears in a gear range and an auxiliary transmission (B) capable of shifting between high and low, and the auxiliary transmission (B). Is configured to be switched between high and low at an intermediate position of the shift range in the entire shift range. 3. A shift operation of a work vehicle configured to operate the actuators (11), (12), (13) based on forward / reverse operation of the shift lever (26) in a fixed direction to perform multiple shifts. In the structure, the linear portion (L1), (L2), (L3) forming the shift range in the operation range of the guide groove (27) for guiding the shift lever (26) is set to a speed range suitable for low speed work. In the low-speed zone straight line portion having a plurality of shift positions (L1), and the high-speed zone straight line portion having a plurality of shift positions in a speed range suitable for road traveling or high-speed work (L3), The straight part (L2) for the medium speed zone that has a plurality of shift positions at intermediate speed in each of the high and low zones, and each of the straight parts (L1), (L2), (L3) , Adjacent straight lines (L
1), (L2), (L3) is formed by connecting the refraction portions (W1), (W2) provided between the end and the start of each other to form the guide groove (27) in a continuous refraction line shape. The structure for gear shifting operation of the working vehicle.