JP5954289B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle. In particular, the present invention relates to a tractor that is an agricultural machine having a work machine attached to the rear of the machine body.

The tractor turns the power transmission on and off and selects forward or reverse while braking the rear wheels driven by the power transmitted from the engine in accordance with the pedal operation of the operator. A hydraulic continuously variable transmission is provided.

And the technique of the structure which brakes front and rear wheels by operation of a brake pedal, makes the rotation speed of a hydraulic continuously variable transmission zero, and further turns off a PTO clutch that stops driving of a work machine is disclosed. (See Patent Document 1).

JP 2011-230767 A

In a hydraulic continuously variable transmission, the forward / reverse switching is slow, so there is a case where there is no reaction between the operation of the brake pedal and the running and stopping of the aircraft. For this reason, there has been a problem that the interlocking with the PTO clutch off shifts.

An object of this invention is to provide the work vehicle which solves such a subject.

In claim 1, the brake pedal (B) for performing braking of the wheel driven by the power transmitted from the engine (5) according to the pedal operation of the operator, and the transmission of the power are turned on and off. The clutch pedal (C) for connecting and disconnecting the hydraulic clutch (48) according to the pedal operation of the worker, and the brake operation detection for detecting the pedal operation of the worker with respect to the brake pedal (B) In a work vehicle provided with a PTO main clutch (97) for turning on / off transmission of power to a machine (200) and a work machine (202) mounted on the vehicle,
When the brake pedal detector (200) detects the pedal depression operation of the operator with respect to the brake pedal (B), the operation of the clutch pedal (C) is unnecessary and only the operation of the brake pedal (B) is performed. The hydraulic clutch (48) and the PTO main clutch (97) are controlled to turn off the transmission of the power, and the operator's pedal opening operation on the brake pedal (B) is detected by the brake operation detector ( 200), a no-clutch for selecting or deselecting a no-clutch mode for performing control for turning on the transmission of the power to the hydraulic clutch (48) and the PTO main clutch (97). A mode selection switch (201) is provided,
When the brake pedal detector (200) detects that the operator depresses the pedal with respect to the brake pedal (B), the hydraulic clutch (48) is a predetermined time after the PTO main clutch (97) is turned off. The work vehicle is characterized by performing control to turn off the vehicle.

2. The isochronous control according to claim 1, wherein after the hydraulic clutch (48) and the PTO main clutch (97) are turned off, the engine speed is reduced to a substantially idling speed to perform isochronous control . It is a work vehicle.

According to the first aspect of the present invention, the clutch clutch 48 and the PTO main clutch 97 are simultaneously turned on and off by operating the brake pedal B, so that the no-clutch mode in the field can be used. Since the hydraulic clutch 48 is a multi-plate clutch housed in a clutch pack, the reaction is good.
Further, when the brake operation detector 200 detects an operator's stepping operation on the brake pedal B, a control is performed to turn off the hydraulic clutch 48 after a predetermined time since the PTO main clutch 97 is turned off first. Therefore, it is possible to reduce the influence of the work system load and prevent engine stalls.

In the second aspect of the present invention, the engine speed is reduced to substantially the idling speed after the PTO main clutch 97 and the hydraulic clutch 48 are turned off, and the isochronous control is performed. Immediately after idling speed is maintained and the idling speed is maintained by isochronous control, fuel efficiency is improved without using wasted fuel.

Side view of tractor Control mechanism diagram Perspective view of the tractor near the brake pedal Block diagram of main parts of control mechanism Flow chart Transmission diagram of tractor power transmission mechanism Perspective view near the instrument panel of the tractor Perspective view near the panel dash part of the instrument panel of the tractor Side view showing the action of the brake pedal

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The configuration and operation of the tractor according to the present embodiment will be described. The configuration of the tractor according to the present embodiment will be described with reference to FIGS.

FIG. 1 is a side view of a tractor according to an embodiment of the present invention, and FIG. 2 is a block diagram of the tractor according to an embodiment of the present invention. FIG. 3 is a perspective view of the vicinity of the brake pedal B of the tractor according to the embodiment of the present invention. The tractor according to the present embodiment is an example of the work vehicle according to the present invention.

The tractor according to the present embodiment includes left and right front wheels 2 and 2, left and right rear wheels 3 and 3, an engine 5, a forward and backward clutch 48, a control mechanism 300, and the like.
The forward / reverse clutch 48 is a clutch for turning on / off the transmission of power and selecting forward or reverse. The forward / reverse clutch 48 is an example of the predetermined clutch of the present invention, and is also an example of the hydraulic clutch of the present invention.

The predetermined clutch of the present invention is the same clutch as the hydraulic clutch of the present invention in the present embodiment, but may be a clutch different from the hydraulic clutch of the present invention. For example, the hydraulic clutch of the present invention may be a forward / reverse clutch, and the predetermined clutch of the present invention may be a mechanical clutch different from the forward / reverse clutch.

The brake pedal B is a pedal for performing braking of the rear wheel 3 (rear wheel and front wheel) driven by power transmitted from the engine 5 in accordance with an operator's pedal operation.
The brake operation detector 200 is a means for performing detection related to the operator's pedal operation on the brake pedal B.

The brake pedal B includes a left brake pedal BL and a right brake pedal BR. The left and right brake pedal coupler 205 is a coupler for coupling and non-coupling between the left brake pedal BL and the right brake pedal BR.

The left / right brake pedal connection detector 206 is a means for detecting whether the left / right brake pedal connector 205 is connected or disconnected.
The clutch pedal C is a pedal for connecting and disconnecting the forward / reverse clutch 48 for turning on / off the transmission of power according to an operator's pedal operation. The clutch pedal C is also a pedal for connecting and disconnecting the first high / low clutch 24 (see FIG. 6) and the second high / low clutch 25 (see FIG. 6).

The clutch operation detector 207 is a means for performing detection related to the operator's pedal operation with respect to the clutch pedal C.
The no-clutch mode selection switch 201 performs control for turning off the transmission of power to the forward / reverse clutch 48 when the brake operation detector 200 detects an operator's stepping on the brake pedal B with respect to the brake pedal B. When the brake operation detector 200 detects the operator's pedal opening operation with respect to the pedal B, the no-clutch mode for performing control for turning on power transmission to the forward / reverse clutch 48 is selected or not selected. Means.

FIG. 4 is a schematic block diagram of a main part of the tractor control mechanism 300 according to the embodiment of the present invention.
The controller 301 executes a control operation according to a signal read by a reading process for a plurality of switches and sensors, or executes a display operation on the meter panel 302 using CAN communication. Arithmetic unit.

The no-clutch mode selection switch 201 reduces the connection pressure of the forward / reverse clutch 48 in response to the operator's pedal depression operation on the brake pedal B, even if there is no operator's pedal operation on the clutch pedal C. This is means for freely selecting the operation and non-operation of brake stop control using clutch stop. The low pressure of the connection pressure of the forward / reverse clutch 48 is for improving the response at the time of reconnection.

When the extremely low speed with the largest reduction ratio of the auxiliary transmission is selected as the number of auxiliary transmission stages in the auxiliary transmission unit 154 (see FIG. 6), the first high / low clutch 24 (see FIG. 6) and the second high speed are selected. The connection of the low clutch 25 (see FIG. 6) is turned off.

This is because there is a possibility that the vehicle may move due to the high torque, and it is possible to prevent the piercing that is likely to occur in such a case.
By setting the connection pressure of the forward / reverse clutch 48 to a low pressure that is not completely zero, it is possible to improve the responsiveness when the operator's feet are separated from the brake pedal B and the vehicle is restarted.

When the speed reduction ratio of the auxiliary transmission is larger, the forward / reverse clutch 48 should be boosted in a shorter time in order to improve the response.
Since the operator can activate or deactivate the brake stop control, it can flexibly respond to the need to operate the tractor using the clutch pedal C as before without using the no-clutch mode. It is possible to increase user adaptability.

If it is desired to operate the tractor using the clutch pedal C without using the no-clutch mode, the forward / reverse clutch 48 is turned off in response to the depression of the clutch pedal C, and the first high The connection of the low clutch 24 (see FIG. 6) and the second high / low clutch 25 (see FIG. 6) is also turned off.

The forward / reverse switching operation detector 208 includes a forward / reverse switching switch 210 for switching the traveling direction of the tractor, which is forward, neutral or reverse, according to the switching operation of the forward / reverse switching lever 209 by the operator. Have.

The brake operation detector 200 includes a brake switch 211 that is turned on / off depending on whether the brake pedal B is stepped on by an operator.
The clutch operation detector 207 includes a potentiometer type clutch sensor 212 that can detect the amount of depression depending on whether or not the clutch pedal C is depressed by an operator.

The left and right brake pedal connection detector 206 is a switch for detecting the state of the left and right brake pedal connector 205, which is either connected or not connected, in accordance with an operator's fitting / unmounting operation (illustrated by arrows). (Not shown).

Basically, in the brake stop control described above, the left brake pedal BL for braking the left rear wheel 3 and the right brake pedal BR for braking the right rear wheel 3 are connected. It is activated only when

An operation of the tractor control mechanism 300 according to the present embodiment will be specifically described.
Of course, switching between selection and non-selection of the no-clutch mode can be easily performed using the no-clutch mode selection switch 201 as described above. For example, it is preferable that such switching cannot be performed under a specific condition with an emphasis on safety.

An operation of the control mechanism 300 accompanied by a change from the state where the no clutch mode is not selected to the state where the no clutch mode is selected will be described.
When the no-clutch mode is not selected and the left-and-right brake pedal coupling detector 206 detects that the left-and-right brake pedal coupling 205 is not coupled, the no-clutch mode selection switch 201 is used to select the no-clutch mode. The operation of the control mechanism 300 is considered to be invalid.

According to the operation of the control mechanism 300, the no-clutch mode selection switch 201 is used only when the left brake pedal BL and the right brake pedal BR are connected. A change from a state in which the no-clutch mode is not selected to a state in which the no-clutch mode is selected can be permitted, and safety can be improved.

When the left brake pedal BL and the right brake pedal BR are not connected, the state of the brake pedal B is an unstable state in which one-sided effect can occur, and if the no-clutch mode is not selected, the no-clutch mode is selected. If the change to the state where is selected is permitted even in such a case, the operator may perform an operation to operate the brake stop control described above in a situation where an accident is likely to occur. .

This example will be described with reference to FIG. 5 which is a flowchart for explaining the operation of the tractor control mechanism 300 according to the embodiment of the present invention.
A reading process is performed on the switch, the sensor, and the like, and it is determined whether the no-clutch mode is not selected (step S11).

As a result of determining whether or not the no-clutch mode is selected (step S11), when it is determined that the no-clutch mode is not selected, the switch operation for selecting the no-clutch mode is selected. It is determined whether or not the switch 201 is used (step S12). When it is determined that the no-clutch mode is selected, the process returns to the subroutine call.

As a result of determining whether or not the switch operation for selecting the no-clutch mode has been performed (step S12), when it is determined that the switch operation for selecting the no-clutch mode has been performed, the left brake by the left and right brake pedal coupler 205 It is determined whether or not the connection between the pedal BL and the right brake pedal BR is detected by the left and right brake pedal connection detector 206 (step S13), and when it is determined that the switch operation for selecting the no clutch mode is not performed. Return to subroutine call.

As a result of determining whether or not the connection between the left brake pedal BL and the right brake pedal BR is detected (step S13), when it is determined that the connection is detected, the no-clutch mode is selected (step S14), and the process returns. When it is determined that the connection is not detected, the no-clutch mode is continuously deselected (step S15), and the process returns.

The operation of the control mechanism 300 accompanied by a change from a state in which the no-clutch mode is selected to a state in which the no-clutch mode is not selected will be described.
In a state where the no-clutch mode is selected, when the brake operation detector 200 detects an operator's pedal operation on the brake pedal B, the left / right brake pedal connection detector 206 is disconnected. Even if it is detected, the control mechanism 300 operates such that the state in which the no-clutch mode is selected is not released.

According to the operation of the control mechanism 300, when the operator operates the brake pedal B, the no-clutch mode is selected even if the left brake pedal BL and the right brake pedal BR are disconnected. Therefore, it is possible to prevent a change from a state where the no-clutch mode is selected to a state where the no-clutch mode is not selected, and it is possible to improve safety.

FIG. 6 is a schematic transmission diagram of the power transmission mechanism of the tractor according to the embodiment of the present invention. About the power transmission mechanism of the transmission in the transmission case 8 in which the front case and the rear case are assembled together, the PTO output shaft connected from the engine 5 to the front wheels 2 and the rear wheels 3 and a rotary work machine (not shown). 111, the transmission mechanism to the gearbox will be described.

The main transmission unit 150 will be described. The rotation of the engine output shaft 20 of the engine 5 is transmitted to the input shaft 21. Power interruption by the clutch pedal C is performed by the forward / reverse clutch 48, and the forward / reverse clutch 48 serves as a main clutch.

The first input gear 22 fixed to the input shaft 21 meshes with the first low speed gear 26 of the first high / low clutch 24 and the second low speed gear 27 of the second high / low clutch 25, and fixed to the input shaft 21. The second input gear 23 meshes with the first high speed gear 30 of the first high / low clutch 24 and the second high speed gear 31 of the second high / low clutch 25.

When the first high / low clutch 24 is connected to the first low speed gear 26 side, the rotation is transmitted from the first low speed gear 26 to the first clutch shaft 28, and the first high / low clutch 24 is connected to the first high speed gear 30 side. , The rotation is transmitted from the first high speed gear 30 to the first clutch shaft 28.

When the second high / low clutch 25 is connected to the second low speed gear 27 side, the rotation is transmitted from the second low speed gear 27 to the second clutch shaft 29, and the second high / low clutch 25 is connected to the second high speed gear 31 side. , The rotation is transmitted from the second high speed gear 31 to the second clutch shaft 29.

The first high / low clutch 24 and the second high / low clutch 25, which are the same hydraulic multi-plate clutch, respectively reduce the rotation of the input shaft 21 in two stages of high and low at the same reduction ratio. 28 and the second clutch shaft 29 are transmitted.

The first high / low clutch 24 and the second high / low clutch 25 are immersed in the lubricating oil, and the first clutch shaft 28 and the second clutch shaft 29 are located slightly above the liquid level OL of the lubricating oil.

An oil supply hole 8b drilled from the left and right opening sides of the case is provided in the built-up portion 181a formed on the front partition wall 181 that supports the first clutch shaft 28 and the second clutch shaft 29 to the transmission case 8. Thus, the fuel is supplied to the shafts of the first high / low clutch 24 and the second high / low clutch 25 from the oil supply hole 8b.

The oil supply holes 8b are provided in a concentrated manner as oil passages in the vertical direction and the horizontal direction, avoiding the bearing portion, instead of the piping in the case.
If an oil filter (not shown) is attached near the oil supply hole 8b, piping can be simplified.

The first high / low clutch 24 and the second high / low clutch 25 are arranged on the left and right in the lower part of the downward inclined portion 8 c of the mission case 8.
The first gear 113 fixed to the first clutch shaft 28 meshes with the second gear 35 fixed to the low-speed transmission shaft 34, the rotation is decelerated and transmitted, and the third gear 149 fixed to the second clutch shaft 29 is transmitted at high speed. The fourth gear 33 fixed to the transmission shaft 32 is engaged with the fourth gear 33, and the rotation is increased and transmitted.

In the transmission so far, the low-speed transmission shaft 34 is shifted in two steps at a low speed, and the high-speed transmission shaft 32 is shifted in two steps at a high speed, so that a total of four speeds are changed.
The rotation of the low speed transmission shaft 34 and the high speed transmission shaft 32 is transmitted to the first sync change 42 and the second sync change 36, respectively.

The first sync small gear 43 of the first sync change 42 and the second sync small gear 37 of the second sync change 36 mesh with the fifth gear 40 of the first transmission shaft 39, and the first sync large gear of the first sync change 42. 44 and the second synchro large gear 38 of the second synchro change 36 mesh with the sixth gear 41 of the first transmission shaft 39, and the rotation is transmitted.

The first sync small gear 43 of the first sync change 42 and the second sync small gear 37 of the second sync change 36 are exactly the same gear, and the first sync large gear 44 of the first sync change 42, The second synchro large gear 38 of the second sync change 36 is exactly the same gear.

The low speed transmission shaft 34 rotates at a low speed, and the high speed transmission shaft 32 rotates at a high speed.
Accordingly, when the first sync change 42 is switched, a further two-stage shift at a low speed is performed, and when the second sync change 36 is switched, a further two-stage shift at a high speed is performed.

That is, the rotation of the first input shaft 21 is shifted by the first transmission shaft 39 to the low speed four stages and the high speed four stages.
The first sync change 42 and the second sync change 36 are accommodated in the mission case 8 by sub-assembling the shifter stay and the shifter.

The case opening of the speed change operation portion is provided on the left and right side surfaces of the case, and is provided above the lubricating oil level OL of the transmission case 8.
As a result , the main transmission unit 150 reads the shift position of the main transmission lever 9200 operated by the driver, and the traveling ECU automatically selects the first high / low clutch 24 and the first high / low clutch 24 which are high / low hydraulic multi-plate clutches. The second high / low clutch 25, the first sync change 36 and the second sync change 42 are controlled, and the speed is changed to the low speed four speeds and the high speed four speeds.

In the mission case 8, the first high / low clutch 24 and the second high / low clutch 25 are arranged on the left and right.
Below that, a low-speed transmission shaft 34 to which the first sync change 42 is attached and a high-speed transmission shaft 32 to which the second sync change 36 is attached are arranged on the left and right.

Thereby, a compact configuration with a narrow left and right width of the mission case 8 and a low height is realized.
Further, the first transmission shaft 39 is connected to the second transmission shaft 45 by shaft connection.

A seventh gear 46 and an eighth gear 47 are fixed to the second transmission shaft 45.
The seventh gear 46 is meshed with a forward clutch gear 49 of a hydraulic multi-plate forward / reverse clutch 48.

The eighth gear 47 is meshed with the reverse gear 51 of the reverse shaft 52, and the reverse gear 51 is meshed with the reverse clutch gear 50 of the forward / reverse clutch 48.
Therefore, when the forward / reverse clutch 48 is connected to the forward clutch gear 49 by boosting the forward clutch 48a, the rotation of the seventh gear 46 is transmitted to the auxiliary transmission shaft 53 connected to the forward / reverse clutch 48 in the forward rotation state. When the forward / reverse clutch 48 is connected to the reverse clutch gear 50 by boosting the reverse clutch 48b, the rotation of the eighth gear 47 is transmitted to the auxiliary transmission shaft 53 in the reverse state.

The reduction ratio is different between forward rotation and reverse rotation, and the reverse rotation is slower. The selection of forward transmission (forward) and reverse transmission (reverse) is performed by operating the forward / reverse switching lever 209 provided on the left side of the handle column on which the handle is erected.

The auxiliary transmission unit 154 will be described. The ninth gear 54 and the tenth gear 55 fixed to the auxiliary transmission shaft 53 mesh with the third sync large gear 56 and the third sync small gear 59 of the third sync change 58, respectively.

Accordingly, when the third sync change 58 is connected to the third sync large gear 56, the fifth transmission shaft 60 is driven at a high speed by increasing the speed transmitted from the ninth gear 54 to the third sync large gear 56. When the third sync change 58 is connected to the third sync small gear 59 side, the fifth transmission shaft 60 is decelerated by the rotation transmitted from the tenth gear 55 to the third sync small gear 59 and driven at medium speed. .

The eleventh gear 57 fixed to the third synchro small gear 59 side of the third synchro change 58 meshes with the fourth synchro small gear 69 of the fourth synchro change 71.
The fifteenth gear 70 fixed to the fourth synchro small gear 69 side meshes with the seventeenth gear 75 of the second cylindrical shaft 114, and the rotation starts from the eighteenth gear 76 fixed to the second cylindrical shaft 114. It is transmitted to the four synchro large gears 72.

A sixteenth gear 74 is fixed to the first cylinder shaft 73 on which the fourth sync change 71 is mounted.
Therefore, when the third sync change 58 is made neutral, the rotation of the tenth gear 55 is transmitted to the third sync small gear 59, and the rotation is transmitted from the eleventh gear 57 fixed to the third sync small gear 59 side. It is transmitted to the fourth synchro small gear 69.

In this state, when the fourth sync change 71 is connected to the fourth sync small gear 69 side, the rotation of the fourth sync small gear 69 becomes the rotation of the sixteenth gear 74 and the speed is lowered. When connected to the fourth synchro large gear 72 side, the rotation of the fourth synchro small gear 69 is transmitted from the fifteenth gear 70 to the seventeenth gear 75, the eighteenth gear 76 and the fourth synchro large gear 72, The sixteenth gear 74 becomes extremely low speed.

When the third sync change 58 is connected to the third sync large gear 56 side or the third sync small gear 59 side, the fourth sync change 71 is made neutral.
As a result, with respect to the rotation of the sub-transmission shaft 53 that has been subjected to the 150-speed change in the main transmission unit, the sub-transmission unit 154 performs four-speed shifts to the low-speed sixteenth and high-speed sixteenth stages. Is shifted.

The sixteenth gear 74 meshes with the twelfth gear 61 fixed to the fifth transmission shaft 60 to drive the fifth transmission shaft 60.
The first bevel gear 62 fixed to the shaft end of the fifth transmission shaft 60 meshes with the second bevel gear 63 of the rear bevel case 64, and from the bevel output shaft 65 of the rear bevel case 64 to the thirteenth gear 66 and the tenth gear. The rear wheel output shaft 68 is rotated via the four gears 67 to drive the rear wheel 3.

The twenty-first gear 117 is fixed to the fifth transmission shaft 60, and the twenty-second gear 118 and the twenty-second gear fixed to the second cylindrical shaft 119 supported by the auxiliary transmission shaft 53 are rotated. The sixteenth gear 77 of the first front wheel drive shaft 78 is transmitted to the nineteenth gear 77 through the gear 148, and the sixteenth gear 74 and the sixteenth rotation of the sixteenth gear 74 are transmitted to the first front wheel drive shaft 78. .

This rotation is transmitted from the first front wheel drive shaft 78 to the second front wheel drive shaft 84 via the front wheel acceleration clutch 79 and is taken over by the third front wheel drive shaft 85, the fourth front wheel drive shaft 86 and the front wheel drive bevel shaft 87. It is transmitted by.

The first front bevel gear 88 fixed to the shaft end of the front wheel drive bevel shaft 87 meshes with the second front bevel gear 115 of the front bevel case 89, and the front bevel output shaft 90 of the front bevel case 89, the first front bevel gear set. 91, the front wheel output shaft 93 is rotated via the front longitudinal axis 116 and the second front bevel gear set 92 to drive the front wheel 2.

The first speed increasing clutch gear 82 and the second speed increasing clutch gear 80 of the front wheel speed increasing clutch 79 are engaged with the first speed increasing gear 83 and the second speed increasing gear 81, respectively. Change the speed increase rate.

As a result, the sub-transmission unit 154 reads the shift position of the sub-transmission lever (not shown), and the traveling ECU automatically controls the third sync change 58 and the fourth sync change 71 to perform a shift.

The first cylinder shaft 73 to which the fourth sync change 71 is attached is disposed below the fifth transmission shaft 60 to which the third sync change 58 is attached.
Thereby, the structure with the short length of the mission case 8 is implement | achieved.

The transmission path of the PTO output shaft 111 will be described. The main clutch gear 96 of the PTO main clutch 97 is engaged with the second input gear 23, and power is interrupted by the PTO main clutch 97. The PTO main clutch 97 is located below the first high / low clutch 24 and the second high / low clutch 25, and is cooled and lubricated with lubricating oil accumulated in the transmission case 8. A PTO transmission 157 is provided on the first PTO shaft 95 to which the PTO main clutch 97 is attached.

The first PTO gear 98, the second PTO gear 99, the fifth synchro small gear 100 and the fifth synchro large gear 101 of the fifth sync change 151 are mounted.
The twenty-second gear 102, the twenty-third gear 152, the twenty-first gear 103, and the twenty-fourth gear 153 are fixed to the second PTO shaft 104, and the PTO reverse rotation gear 105 is attached to the counter shaft 106. It is supported.

When the first PTO gear 98 is slid and meshed with the twentieth gear 102, the second speed is obtained on the third PTO shaft 107.
When the first PTO gear 98 is slid and meshed with the second PTO gear 99, the rotation of the first PTO shaft 95 is transmitted to the third PTO shaft 107 via the second PTO gear 99 and the twenty-third gear 152. , 4th speed is obtained.

When the fifth sync change 151 is connected to the fifth sync small gear 100, the rotation is transmitted from the fifth sync small gear 100 to the 21st gear 103, and the first speed is obtained.
When the fifth sync change 151 is connected to the fifth sync large gear 101, the rotation is transmitted from the fifth sync large gear 101 to the twenty-fourth gear 153 to obtain the third speed.

When the PTO reverse rotation gear 105 is engaged with the first PTO gear 98 and the twentieth gear 102, the rotation of the first PTO shaft 95 is transferred from the first PTO gear 98 to the twentieth gear 102 via the PTO reverse rotation gear 105. It is transmitted to the third PTO shaft 107 and reverse rotation is obtained.

The first PTO gear 98, the second PTO gear 99, and the fifth sync change 151 include the first high / low clutch 24 and the second high / low clutch 25, the first sync change 42, and the second sync change 36. Located between these underneath.

The rotation of the third PTO shaft 107 is transmitted to the fifth PTO shaft 108 via the fourth PTO shaft 156, drives the first PTO output gear 109 and the second PTO output gear 110, and is further decelerated to generate the PTO output shaft. 111 is driven.

The input shaft 21 and the fourth front wheel drive shaft 86 are located in the center of the left and right sides of the transmission case 8, the first high / low clutch 24 and the second high / low clutch 25 are disposed in symmetrical positions, and the high speed transmission shaft 32 and The low-speed transmission shaft 34 is disposed at the left / right symmetrical position, and the fourth PTO shaft 156 and the auxiliary transmission shaft 53 are disposed at the left / right symmetrical position.

The fourth PTO shaft 156, the auxiliary transmission shaft 53, and the fourth front wheel drive shaft 86 are disposed below the inside of the transmission case 8, and form a vertex of a substantially isosceles triangle in a front view.

As shown in FIG. 7, a no-clutch mode lamp 213 that lights up or flashes when no-clutch mode is selected and turns off at other times is displayed on the monitor in an easy-to-understand manner. Do. FIG. 7 is a perspective view of the vicinity of the meter panel 214 of the tractor according to the embodiment of the present invention.

Even if the no-clutch mode is selected, when the brake switch 211 is off, it is difficult for the operator to know whether the no-clutch mode is selected, but the no-clutch mode lamp 213 is provided. Therefore, the operator can easily confirm whether or not the no-clutch mode is selected.

As shown in FIG. 8, the no-clutch mode selection switch 201 is laid out on the panel dash 215 portion of the meter panel 214.
Thereby, even during operation of a tractor in which the worker is often looking forward, the no-clutch mode can be switched between selection and non-selection using the no-clutch mode selection switch 201. Can be done easily.

When the brake pedal detector 200 detects that the operator depresses the pedal with respect to the brake pedal B, the hydraulic clutch 48 and the PTO main clutch 97 are controlled to turn off the transmission of the power. And When the brake operation detector 200 detects an operator's pedal release operation on the brake pedal B, control is performed to turn on the transmission of the power to the hydraulic clutch 48 and the PTO main clutch 97. .

FIG. 9 is a diagram schematically showing the released state and the depressed state of the brake pedal B.
When the brake pedal B is depressed to the first depression position L1, the brake switch 211 is activated and the brake is activated. Simultaneously with the operation of the brake, the hydraulic clutch (forward / reverse hydraulic clutch) 48 is turned off, and the PTO main clutch 97 is also turned off.

In addition, when providing a time difference that first turns off the PTO main clutch 97 and then turns off the hydraulic clutch 48, the time difference may be provided by the control program at the position of the first depression position L1, The PTO main clutch 97 may be turned off at the preceding depression position L0, and the hydraulic clutch 48 may be turned off at the first depression position L1.

Thus, by operating the brake pedal B to simultaneously turn on and off the hydraulic clutch 48 and the PTO main clutch 97, the no-clutch mode in the field can be used. Since the hydraulic clutch 48 is a multi-plate clutch housed in a clutch pack, the reaction is good. Further, since the hydraulic clutch 48 is a forward / reverse clutch, the no-clutch mode can be used regardless of whether the forward clutch is selected, the reverse clutch is selected, or the forward / backward clutch is frequently switched. Become.

In addition, a PTO main clutch single switch 203 for turning on and off the PTO main clutch 9 independently, that is, manually turning on and off the PTO main clutch is provided. Further, as described above, the PTO main clutch interlocking switch 204 that turns the PTO main clutch 97 on and off in conjunction with the operation of the brake pedal B is provided.

Accordingly, it is possible to freely select whether or not the no-clutch mode can be used during work traveling in the field while keeping the no-clutch mode selection switch 201 in the on state.
When an operator's pedal release operation on the brake pedal B is detected by the brake operation detector 200, the hydraulic clutch 48 is controlled to be turned off a predetermined time after the PTO main clutch 97 is turned off first. As a result, the impact on the work system can be reduced, and engine stalls can be prevented.

After the hydraulic clutch 48 and the PTO main clutch 97 are turned off, the engine speed is reduced to a substantially idling speed to perform isochronous control. As a result, the engine speed immediately becomes the idling speed when not running or working, and by maintaining the idling speed by isochronous control, fuel efficiency is improved without using wasted fuel.

Further, when the brake operation detector 200 detects an operator's pedal depression operation on the brake pedal B, in the case of performing control to turn off the hydraulic clutch 48 after a predetermined time from turning off the PTO main clutch 97 first. The hydraulic clutch 48 is turned off after confirming that the rotational speed of the PTO output shaft 111 is zero. Thereby, the influence of the PTO load can be reliably eliminated.

Further, when the brake pedal detector 200 detects that the operator depresses the brake pedal B, the PTO main clutch 97 is turned off as described above. At this time, the left and right brake pedals BL, Suppose you step on BR at the same time. Since the left and right brake pedals BL and BR are not connected during work running in the field, it is necessary to intentionally step on both brake pedals. Thereby, it is possible to prevent the operation while turning from being interrupted.

B Brake pedal C Clutch pedal 5 Engine 48 Hydraulic clutch 97 PTO main clutch
200 brake operation detector 201 node on the clutch mode selection switch 202 working machine 203 PTO main clutch alone switch 204 PTO main clutch interlock switch

Claims (2)

A brake pedal (B) for braking a wheel driven by power transmitted from the engine (5) according to an operator's pedal operation, and a hydraulic clutch (48) for turning on / off the power transmission A clutch pedal (C) for performing connection and disconnection in response to the pedal operation of the operator, a brake operation detector (200) for performing detection related to the pedal operation of the worker with respect to the brake pedal (B), In a work vehicle provided with a PTO main clutch (97) for turning on / off transmission of power to a work machine (202) mounted on the vehicle,
When the brake pedal detector (200) detects the pedal depression operation of the operator with respect to the brake pedal (B), the operation of the clutch pedal (C) is unnecessary and only the operation of the brake pedal (B) is performed. The hydraulic clutch (48) and the PTO main clutch (97) are controlled to turn off the transmission of the power, and the operator's pedal opening operation on the brake pedal (B) is detected by the brake operation detector ( 200), a no-clutch for selecting or deselecting a no-clutch mode for performing control for turning on the transmission of the power to the hydraulic clutch (48) and the PTO main clutch (97). A mode selection switch (201) is provided,
When the brake pedal detector (200) detects that the operator depresses the pedal with respect to the brake pedal (B), the hydraulic clutch (48) is a predetermined time after the PTO main clutch (97) is turned off. A work vehicle characterized by performing control to turn off the motor. The work vehicle according to claim 1, wherein after the hydraulic clutch (48) and the PTO main clutch (97) are turned off, isochronous control is performed by reducing the engine speed to substantially the idling speed .

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